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SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 127 (IN TWO PARTS), PART I

Charles D. and Mary Waux Walcott
Research Fund

CRAZYAN AND RELATED
BRACHIOPODS

PAR tO TEXT

(WitH 269 PLaTEs, IN Part II)

By
G. ARTHUR COOPER

Curator of Invertebrate Paleontology and Paleobotany
United States National Museum
Smithsonian Institution

(PUBLICATION 4253)

CITY OF WASHINGTON
PUBLISHED BY THE SMITHSONIAN INSTITUTION
JUNE 12, 1956

THE LORD BALTIMORE PRESS, INC.
BALTIMORE, MD., U. S. A.

CONTENTS

EEE, LHe Teesreri PIONS . Seis A Wash we Teas Ws 8 om isle Sin Wie aan die OA cine Ria
BPC HCHON ANG SEALE EAD MIC, SCEELIE ose..0.0:0:n ai0:0: 01010 0 s\slala\s\e wiepaialsie sia.e ate oats, ames or
Seether oatiel iF Ge EPICS ates Se. «ae 3)2 MS: sl @ialns cis AAP mise mi gies xm aitiainmae en Bie ambi a’
Renton tT ROME COE © 258616... bajo cenio is lo\oln x alpigmisinin nine Osnie ina teinapindinia Mien fs
GaPESCEONEELG TIMINIGELITIIN cps syascvsceye aucteastoe ete yee a voyaiss assholes euapegotecel epeis) e¥=Keneys,opacarttoce cbs aatys
ESOGLO Wes TAterialers conta’ cfs s, nletarelcterevoe relat Srodaveie tS biersis de ones asfshas oxcuahs lain ache <aspasb abies
Ree ied ATI FE REY SCHOSLIS Su SIUC aR GE salle « cvaeela sine. a orejapare lala lade o ieuhe ie. 8 inlm ening a yO 2p Salo ds ncaa
Acknowledgments ............ a pafanatorsjwustonsvoiansieiexe sieiekepuensteselaislekelepniehss Se covaeised aah renee
PGeAtion Of types ale ADPTEVIALLONS! Je Lisis wis oo oie.oi wlsiwre, ninieievaietesnayn iaudloiste meine =
INGLES ON tHemCORGE latioiny Cla tbe i. ajo (ay<]-sersiaveerctasiaieieiei-Warcioleiele ehedatiy tens lseleeiauavakenniersiciens
Geographic and geologic setting of the formations.............eeeeeeeeeeeeeeeeee
Brome NI esa OUTAGE Leh SICA ey eI a oft scl raha voresahatorctere laPeposanare aschouats laiephepaovatos miaichibolteheralocituts Shea Caitaieere
PE cay Mes MEDEA SORUCS \< eis! af at atatus at odatcrannratuie/winlete sais eintetatejnl ote eeelaie itahe ac aatals bia atisal Malate
Worrelationn Git ablenE lead) SETIES SHO 2 2/5 kcorcte/asausinschsiaysiaynadias nih ones payee sihi aupanasay ais
MBAOTTET EMOTE SELIGS IC OY Cie SY. atc shics sh sar att arese\ayo: ave) act io} olan hehe Viduka ia Sogn aah a STON BY Scariae
Correlation Of Longe (Point (SOnIesis iis 6% oie:a7-201 <5) ecarsrerm tape tehaigdanayatevalataresniainn dh
ACO WAAL SAM OCEAN HRs ccc enatcr anata’ avovacaysvekohaovores evens lshonaitave PLAS eis lacey We EER ie
FLUE ere AIT SE LIES: 12 vaccher wey cnct ovayelerstel stelaicy-enchheteponenexalats) skapnbap a aeoioRol qcor cuales taueyolebaiey
> St. Wawrence and Ottawa) Valleys and adjacentsareasin «)-poyatyet- sie sporciveitisieiaters «1 <1-
Rare ler S So. hs OLE TOR SA atanat ere snerstsnarsr ate) aver obLer qian SIRs akin ub deere eel
Meet? LOPITIALIONN SRE <idls coeds dad STAVE: ww: orxfualiateyoiouapaily luau tale: ioe breganaiarh
Correlation Gb | Mingan toemationy x. cal. Ae sacle eres ruersinnesd bile herds oyun oss
Oehecy City> FESO. -aivaee viele vic aheletalepere sjstets UATE A chugs OR IE RO eet atts
Ouepee’ City TOCmMIab OMe sas eens cna Aas adh aiken elt lp qnakpeineenee eaten gavel «
WIOMESEAIN ANAS VIGIHILY ..sio.c oncindnones qucdeoasenl qaadengeente dananltatontan ss
SPN r finoninia EIOID i sa<\ ne So ove alavelevaneliviniei ovo sis alet erenes buenas sta laverare Polat ore eyelet nal
Pameliattorirattotiasss 22), SUP rest Rese Soy) <aloxeneld siete: way occto ronal sity deiatereys
ORV VAN LEM AEO TINIE OMS. erciadic cre ocie emo ueersickere exohaier oaspeeg a anarenee eed Senet siebeanrar ate, &
GHawMonercOninia Llomsaeire eateries cree ehoversrovele, o S.o1nic) apateoncnaxersy = (oeberebtle! seperate sox
Oftawa’ Valley; vicinity’ Of Ottawaia «.< ¢,i)s.¢..0:5,0'0,0.0,s,5,0,05e,sppllememts aaivlad wpabtattes ws
PNET TOT MIALUON, <2) 5 4029. 4,0,4 8 Bia 5 6 059'0,3,0h4,)5 8.0 oes. apes ape naraees femae wimate Ne
Rockeliffe member’of Aylmer formation. «3. «34. swweawdnaawd «ba satestanle

St; Martin’ member of Aylmer formation) £2 « wadspaciaaa& eeiands «hs ele ble
Correlation ‘of Aylmef! formation.sirt ts ages «4 hijscsysiayadeneyet 9 potato wbars >< ef
Ottawa efoup (or formation) 45s. 2. ss. aeapiolnaleag dy oath cos eset
Pamelia formation’ Res 5 Sole SESS as sa a)ajars, te) 4) 4,5,0,0)0 ate aelates

Howyville formation 10h ob. ee te 5.8 25 5 5.0, 5,5y0,5/eaye,sereletons ete seh atte Bhs
Correlation of Lowville formattonwed: aacacle ds den chines dae einen ae are
@hanmiont formation 64 5c 5% <5,2 5.54 /5 5)005, 5 5,4,800 5.9/5 yeseuesdy8.08 0,0 apaneranties ot yet etal 2
Correlation and! discussiom of fatunals list. 4: sehen «se outs Wererete ole gable syeie ie
Rockland formation sek creek emeiatals a bustle ae Soler Baye. leocec6 se gierebearars eich axangdé «
Correlation of Rockland formation and remarks on the listed brachiopods. .
Head of the St. Lawrence Valley in New York and adjacent Canada..........
Patrician HOLmIAtlOL ss sic sle sie store spaslo eco lecs celavsge Slatue HS en ois stile etoiiebepeloneias eh themed wn :
Mow vallet formation sc os.4/es lose oe ls a s,s ae af adh eae ded oA bhectoiatd's ss
Chaumont formation toned. yhedeatt, den sides baeietie walawncen week he tits ss

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ry
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bo HHH NHN ND BS BF BH BB BS eS SB Re ee aOR OR OR OR ORR OR OR OR OR ORO
HRhWN HD NOOO UOMO WWAONNNNN DADA AUH NUS SPWWW WWW N

iv SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Page

ROCHE AOPIET ENON ho ii 0 ose vic uel nba hes 4h e's Soe ee WES RE ete Ore a, Ca a 24
Selby tether of Rockland fortaations s/c. iawceses ssh cme egos eee sd ace 24
Napanee member of Rockland formation. 1c i.)bev cece cs tcc ee deceveenens 25
Section at Coboconk, central Ontaniosccents rawness <piisycdveis avs ve deas eee 25
SAGO Wy MME CIPI ATION 5/530 sia iors cowie Maarten Minn ce ays hae APE See cueoni el avelle ase reine 25
Gail River: Sarsahions J2c.c ses 0 Hens ee eee ee eee eee a ca ceee oil eee 25
Rioore hint Teriation..'.'.'...nss decuet sane memati eine aoa: ce tpncten 26
RRIOCEUIE | TORTHATION” Scaisic cs ods as me ton wie ate ree teeroma ee parce eh car os can 26
iene slat region o's oo ete ees alee ee oe ts readies aie cine eee 26
WPerpurt MG OTTNALION eo ine ss oes cs eto uote Sle ee LOT Ee ee a eee ie as aah ae 27
Stree Grreist TOLMATION . s''. s- o oe mics Mics eee eRe eR Oe e EERE Otel e cies ofertas 27
Cincher tslated formation... sees a siettien bo oc otis d= a Stee atontcielae «sane 27
= Champlain. Mohawk, and’ fludson Valleysirsccuscactnsan cies iba sinns« peg pemee 27
Ghamipiai Valley CwestSiG@) ss cares sa tie. ant eierethe ue 3 Cie che gta neue ore aces a iol ecateiee raf
Pay Omit: LOTMALMOM sso (.4 ie de stares one svesyalerefelsieteheluater sheet are. opets Bic saleisis tepals 28
Correlation of Day “Point; formation. aus tiacves coe ch ol cus Se sem cetede wee 28
Crown Pome tormapion. A camer cea ards et atnray Sen eee ste octane ae cae 28
Correlation of ‘Crown “Point torhiahions <=. + se eee nos he eo ceo tepiceue see 29
Walcoti fOrimattont (1c oie a iote steals ater aioe tele reas MOLES Ce eee ete 29
Carrelatinn’ of; Valcourt formation... cc onc sc ccc es eine soins oelo es ieraromenes 29
Paw ile fOnniation 5.7... foe ome apereinte sea a are ore rc ae ee so & has Sao nice ee 29
GienanOnt TOMMIALION SO co miten a tee oo oe ote oe oe et are cr ael a Cena nie eer ee 30
mreasterdad SOTMAION, "i's sie os henge eceleis ote ow ees cre ta eg oe sie esl See eee 30
iste la" Motte Torindtion’ '.) cee eee tates ate cies,» scetss 8 sss 0) nie aganaia leit eee ake 30
Correlation of Islela’ Motte"iormatiOn ss co. sce tlt ec ec os Gee gn eae co tes 30
Paalinshare thrust slice ss Fe tone ee ole ce see ce ee aercte ra te ere eae 3I
Cririplain Valley (east sider eho iclee es ba age acne ean ce are eee 31
Correlation of formations on the east side of the Champlain Valley........ 32
Lower Mohawk and: Upper ‘Hudson ‘Valleys ioctl c oe nate cea cca 32
Amsterdam formation (Mohawk limestone of Conrad).................000. 32
Correlation ‘of -Amsterdam: formation...A.0.6). eile cena de teat aaa 33
isle tax Motte formationcsh nce eo ae Ae ae lane cee 33
Hudson Valley region (Albany to Poughkeepsie)............... cece cece 33
Normanskall- formation’ -o tar Eee eR neh ee eee ae eee cir 33
Mount: Merino: member.to5. chitin ste elses oe eter ae ticks oetentie ies 33
Adstin- Glen: miemtber-.rc.ro1ehe ssarcrs rests tate SORE a te See Oe ohttete bo Ste ite 34
Rysedoré. conglomerate: +s'+.1.hrcroccrciharateteehetcbbatetshalaleletttotetets Sen ae ets erate ae 34
Vicinity: of. Poughkeepsie, Nu Vo... GES, Fa ee IES sare 35
Micinity. of: North Cambridge, :N. Yes]gerey, RIA, o. POCO A rents. o 36
4. The Appalachians -( Pennsylvania to: Alabama) re en Seer ees 36
Facies .in the Appalachians: ici csicnecr irate iat te es oe ds ee. PERE ately 38
Airline formation +.+.:.:araree:araiaritetars!atatelatehatatatetetatatahetatutetatatevata «Sen ete iets aitlae ales ats 4I
Correlation: of Arline formation.:.-.:..:(870 08/078 SAO: A I eee. 43
Arthens: £0 rma tinder reeacorstenetetaicteterctalatotatatetatetetitetitetotaPatatotohate, MEE oes oie e lomin s 43
Correlation. and. fossils of Athens formation!) HUI. OP PRI. 44
Atttalla- f0rmatione os: :.reerereiateietelstaten tolatatetetetetetle tote ielate ee ene a ees eee een wie 45
Bacon Bend. member: of -Sevier formationee: 2 eines. seek feces lev oisreie 45
Baiysi LOmMAti OM) *reercierste ters tetetevateteratotatetetatete etetetaletetaleteletetelerdefacetrs siete, che ol ctelsie ertie 45
Worrelation of ‘Bays formation? 2° SOPOT, are Pa ek es 45
Benbolt. £orriatior yes ee Pee IG BME SE EB, PPE Ete, GENE TUN, ofits 45
Beribolt formation in- Vir wisla «-.octersrereseracetstetaroceretateteretats CURE Res data elke 46
Benboltformations in Tennessee orcs. sotetorcsivocorare bene rotate oleate trai an eet t treet 46

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER Vv

Page

SME PEE SUID NE Tg. cisierr ete vere 'e's bles oe cee gel oeeistle sete ates «feghepslt.s 48
ERE sa Raat HONTIALEL OM sce va lcve aro’ ove tp ialanang’s eis were he iGkalaneie wnerotagelh tapered -vspererst eee ease: 48
lack ford GOrmA ON. ...,.0ie0's2e-eteotbiasset> Gteuoosns b>: de qocheyaaiew ashalronste« 48
Bilgelshtousesfosimatomyy pens alm aeleie wiele ieipieleiele cis ous in chia io oiafenatobonersel merce ajtae:- 49
Botetaumt formation) ) ii. 000% sbo> oe Reseed cabal ha -eadeee dyationdd:. 49
Correlationyof Botetourt, formation,..<..tareiewrary.moetserae- tis raitierdarstore ads) -vee 50
Bowenttonmation se, 2:26.. oSaeeeiasehreeteriop te Ato. sradlienisp gestatiodd=. 50
Burkes Garden member of Benbolt formation.........00 ...ccesceceewcceece 50
GanevGreeleformation ts, } ase antares eebsertt wetness hada» Bee. ctembteersrete! the o,0:0 51
Gaslinailimestone i...) bers seis ieei wie o ein Win isco wurlene wie reper toate oS ere bospavel anand «xe 51
Centre Hall member of Nealmont formation. .............c.ceeeeesceeceees 52
Chambershurei formation. |.....hasdtaeaish aera dd «Seq sreratletenisy. bistete thsi: 52
Chatham: Tid) formation... co. Aen -asmietha- jo qokent. allt. onen ds. 53
Correlation; of Chatham: Hill formation yt ..teny,).iaeuyen. 2a. mardtadswetsebsioeie 53
Ghickaimanoa limestone: 5 ..j5 bic cos meicie® else eae trnater Bese atew panies 53
Ghotasiormation i. Deswed dessa ee's shotiteaes? elise a. de sedans oe 56
Gliteldetormationier wat i. Soi wlowinewe ous coiew sabia e eee. e REI Oita te. 56
Aifheld Peroni suis poo rece oe oRepaeIRs “ems t <tolsdet- de tebialavsie a> .<.< 56
Clover member of Loysburg. formations; 63 «scat. ia was} diabh wetrenit.t.. 56
Gollicsstownoformation) osc sess oreo cas atte bikie Ba- Cc eomaa. <2: 56
Gorrelationvot Gollierstown formation, . .oo...- oo. -cesksses «ee eieelemacice. 56
Columbianasfonmation: jo os. doce. pmseeeek oe eieetietishade te oweablenbot recto sc. 57
Custin formationy Saved also oc cree cic wie ewe Pein ve wes Hi@eleernen a wlare deci h ts be 57
WD OLHLOTMALOWWE:: 6s crocs prec ieiow aid wee w LHNGTROR OR cies AL ONs de Fel ARTE EE eters: 57
CopcelationyotmDot, fOrmatiOnig oicee cuss coir ve oleh oh RRO eaee cekeals 57
Donelasake member of Lenoir; formation, .\...\. 0+. teetemees aeeieeseet. 57
Doylesburg member of Shippensburg formation.................00.000 eee 57
Correlation, of Doylesburg, member... «-o.rieeery see msieie SOR RaOD “INET & 58
Mrgaen, TOemaHon veins sess sex pelese coe CAcicw ie wace steed -cinaath »iepiag hd. < 58
Bidinb ip oyOLMAtlOUls oc cicc cue wee wwe owes oeup ou otto Reet oe ReReete sets. 590
Beaawacmation Siu Joi Uaresiie coer ccs redveccre +See him aponne eM... 60
Correlation yot dE fina, FOrMaAlOs eee nieces c een ou nthieeiebht= Se eple eee =< 61
Peamlestenormiamonis, }. Louie fdeses vel oe oes ore eee OHMS ARIOOeR 61
Eidson member/of. Lincolnshire, formation. . { ssjoshvc.) sewtiacwzot .wrindeodd.. 61
Bere i OnmaAMOR ALES oe edececeevccwe cveweravev cane e Me@ateeel assed... 62
Bway ORInAtion, ee ate Gets toe elne eee cic ieee op wneteas Peete Sapa eds. 62
GorrelationotHlway, formation. ... 46.0 recesses Mette RO ve. teRd.. 62
Eyerjameniber of) Hatter. formationstinasck -iwunies. 3. sedonunn Heh olets. 62
Correlation: of Eyerimemberiitey o. is cceccoesccee o> HORIeaw. Sun Ee 63
Fannettsburg member of Shippensburg formation................eeeceeeees 63
Correlation of -Fannettsbure:member..cetteexel chant. Io.wollalerm>.... 63
Farragut, formation: ceecseu.. i een. mid anions Wes) units oragb aoamek 63
Gorselatipal df Marraent, formations ...5 06 uccensea our elie... 64
Peteer itoneueloet Arne, formation... ...<.<..csoc-c.s..0..0nvtarsel.¢teed.. 64
Pave Oaks carsiatiourlis bore. Pepeetlue. snc cascu ooo smetenneh mnedled... 64
Micanor (OMAHA 0 cena nw Gene, Sule do. tedeswe. geese nid... 65
(Corrclation.of JPleanor formation, ; . .vatdese.piudseotS. is. weliglewwd.... 65
rotten MIGRATION cc bce nner acc dhonavckdemdecsusepesvu dRIRMTOR Mestad... 65
Grazier member on Flatter formation... .uckisanet .eded os .wellaiont.... 65
CorrelationvoreGrazier MeEMDEL: «x oc cc ciou owoe'e oie ofS eAIssed er ees aR Ee : 65
Greencastle ched | .2io0:00..ou20% SEG eet aricd eine daa SE. Herne L550 65
foodie, Creel WOMMALON. bhi y Uccebkk LOWe boon seou cteobioarnat. wen bak. 65

Hattermiormations senzib2. beeese eek ue Basia ta ble bo okte eretlewni asc... 66

vi SMITHSONIAN MISCELLANEOUS COLLECTIONS

Heiskell shale ......
Hermitage formation

wcrc reece eee eee eee eee se eee eeeeeseseeseeeseeeeseseeeseses

weer e eee eee re es ee eeeeeeeeeeeseeeeeesboesreeeseseeeeee

Hogskin member of Lincolnshire formation............cccceeceecceneeeees

Holston limestone ...

eee renee rere reese sreseeeee et eeseseseeeseeesesseeesesesee

Correlation: of .-Hostler member... 0.8 US0s 2. UU GRO . OR EAI. «os
Housum member of Mercersburg formation.........ccccccececeeccecceeees
Hurricane: Bridge. formation, (3.0001 JeG0e. lo, DOVES Pd. OA,

Correlation of Hurricane Bridge formation. ..........c0cecceeecceccesece
Jagksonbure, formation sss ..sisccs snot ence ct4s tise bes MERE he beads s

Correlation of upper Jacksonburg formation..............0.cceceeeeeeees

Kauffman member of
Lantz Mills facies of

Mercersburg formation... .0ViVs0I0! . RIOR NIIOUIa A...
Edinburg formations «ss... RUsC) aes. PIR,

Gorrelation of lower Lantz: Millstiacies ss 4.0). Sew. Lalas a eee sees cee
Correlation of apper. Lantz Mills facies: ....% 640 UC ek. CORN
hemont smember of -Carlim-formationzsects +: es ccs ett cw eeee eae ae eee

Liberty Hall facies of

eee mee eee ee ee eee ee ee eeeoeeeeeereeeeeeeeeeeeeeeeeeeees

Edinburg. fofniatiGnlIyt GIsus i. to. JIL

Correlation -of Liberty: Hall: facies... +..10 046100. 00Oerset le Moise divide x
Isincolnshire- formation: <<< <> << cla eter ntact erecta latats ate bibtaieche a tates: s aye
Gorrelation- of “Lincolnshire formationic..<ccn sss ctoeotee cee aeeleles eentote ne

Little Oak formation

eee erm eee mee ower eerste eee eee eee eee eee eeeeeeeeeeeeeeee

Correlation. of Little: Oals formations «<< <sici elem sia e es sian o obMeIne etree eeeethete
hone, Savannah, formation... . ssi ssccte wk sOuseee ge «Mele «ke AOWRIT toute one

Loysburg formation .
Mahan formation ...
Marcem formation ..

i

ee oeee reese eee eee eee eee eeeeeHeeseeeeee eee eeeeeeeeeeeee®

eee reer tere eee eee e error e eee ee eee eee eee eeeeeeeeseee®

Martin.-Creelc. formation: i... c20satmbis 6 be Ceeesie th 0's Stowe a elete bene ets
Mastiisbure. formation. .+<00+).00cursane ene Neenwrinn x see eee la eleetltear,

Meadow marble ....

eee ee ee eee were wre eee ee eee eeeeeeeeeeeseeeeeeeeeeeeesee

Mercersbure. formation . «s+ 00s cx.s0n deel @eeer eek Bettas tW <CULWUNs Iv. es

Moccasin formation .
Mosheim formation (
Murat formation ....

= facies) sR NIE PRUNES Sita eee. est eeitsr

Comer ere eee ereee seer eeeeeeseeseeeeeeeseeeereeeseseseeeee

eee eee eee eee eee ese eee eee eeeseeeseeeeeseseeeeseeeeeeeeeses

eee eee sree ese eeseseseereeeeeeeeseeeseseseesseeeeeeseees

Ottosea tormation.( == facies) ...5.0..<.0sasnsvenuusheh OOS AMIE EER tes

Paperville formation
Peery formation ....
Pelham limestone ...
Pinesburg member of

eee eeresre ese ee eee reese ee eon eseeseseeeeeeeeeeeeeeeeeeene
CoeceereecececeorcocveeseenneeeseeseGeiessaceeeetreeeneoesesece

eee eeereer reste eee eer eee eeeeeeeseereeseeseeeeereseeeeseeeeese

Shippensburg formation. < cs Wincap Cee Wels Maetcts shes

Correlation.of .Pinesburg member. .. 0:5 )ss030e HMMS Ba POSIT T So 0

Poteet formation ....

Oe ee

Pratt, Berry. FOL AHO 6 6s.aixejee coe ove ous Sees MAD ete ORME S Bails ss 6
Correlation.of, Pratt. Kecry. formation. .....<ssiese ences tek abe aol on tele

Red Knobs formation

0, D0 219 @ (0S 6 0 6,6 © 00 0 68 0.0 8 060 01056 Oe Ue minlale © 8/0) C0256 EP © (0) & 2 Shel ake s

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER Vii

Page

Biel y Valley fOCiMAION. . 1s). si) sales as sie 'ee ale's's'g o's a Siblilanialels «si elsivicltyieienle 3 0 86
Rom Gam formation. +... ........ aeeteands .olskrenient he’. do. anitselvseesd s 87
ROCKS PE HOnIMATIONNs san Serchrele slave aciacie ac elaae ose crerale afobotoreierstcta ote te maittasters tals, » 87
Rodman member or Nealmont formation... = s sees se «= eeiiailo apie oo we lepeie 87
Correlation of Rodman: member... fos aa « Pais eleisiale «lmartsateyers: obotetctoiert «jdaysie 88
1eo\ yee lds aiovn eit) 6007 Ger AAO AISA ICC CCDC AICI OF OO US OOO ais for take 88
Correlatiotr of Row Patrik formation: tree. isonet: stimuiels dele leis cis’olweisreis o's 88
St @lair facies (of Murfreesboro. fotmation® .j 24. % os... «meemnielacle seiseae's bs 88
St. Luke member (facies) of Edinburg formation.............0.seeeeeeeees 89
(Gorselaiion Of St, Luke mactaber. ..;. . uoakries Baeeteck . Res sabelosenet ss 89
Bet Patel) Srey: «5 va canbe se ae huea a Ratsabaee d= MRED Sine <ibiy fete tis “leet Btelve o'er 89
Sole FOPMMATIOT |. oa ac oak bos cas ane § OOM Ce Riese eine Soho habe Geis ewig amleraiersy. 89
Sewer (OCIA (= SUACIES ) rc. o's a's 2 sac oe & cae oan Ses ate eee meneame ae eetS 90
Shannondale member of Benbolt formation... 5.5... wa tleccids eyejelere tre oi ew aiece's 90
SRMBCHSHOCS TORSION 0.) 6 os eases a ea. dicleinaee ds o/awisiarda 4 etndiefapewe «veuginntte ls tate o 91
Savder member of Denver TOrmation. 5.6... cee ac eco 04s eysie sence + Sela wablad ah OI
SPEELS Ment y) FOLMALION » oc, << craves forolsheisie ove otavabebone els exe) ohaysaisiajel> talermrarcedesl= «is1 OI
Stones: RIVE, STOUDs oo i s.c 5 ata bremay o0ld wmetdale - Bee Senrroieie cesberpieae et > 6 © QI
Stover membet of Benner foRmattonias. abiecaystocd se cles esretteyncye «leuraiegai bees «0. 92
SEC ASHMTe TOLMAMOL 2 of. 50s ss 4 2 « tam timrnwalt alae dale vrs opretiminnsienisiertae «== 92
Sureener LOLMAtiOn 62. ..5.is.0 sence Rerevense «eet aseveietena ede obale eehalerst ciate ciawet yotcuegetate'=> 03
AWGLLICOT LORIIAIOTE® cons cc 5 sre ees depeion eave daaieokotay a otal o ea oeakeercniene: che tele aaivedon ens e165 93
Whogipsod Valley TOLMAN’ oi. <5 5.5 cpreemiercqarst «ikl ieet oe ele Sine aneentyeeieh «<6 04
PA TORINAMION sss kee cea a sc naan ga ceste au masisnls qupreaetr «pata s 04
SBimibeae TOLMMATION Soe ics hc ES ESTaN TANS eae eS T: ahons crest cba iens Sxeyeioede ab ditevehepet 0's 04
Valentine’ member of Curtin formation), is... sncaeisieaemm st arc siatieicteiesiasle oes 04
Valley View member of Curtin formations... .ccie doe qicinveininp naslosmaysiels 5's 04
WrestalmriarDle mater en sara clk eae aici as caceituscanarsns 'aeueuslteusieVauebereteiotelaaihe palovasaieecee’ 94
Walker Mountain sandstone member of Moccasin formation..............+: 95
Wan GOVE: LOUIMALOM ccc calves oie. exelers)s oreyela’ cinievegaschepanepadelassiele Ss ere ais anlar stevs 95
Worrclationo® Watd Cove formation... cic. olsiecisie oleic) us aeasiakareefs siajsicieisetere 96
WwreathG@ellt ron matiomn, .vetevsse sobs. coi sve e/ovala'oia-o)5 4,00 sre) Soa cauer sists iovoucuatietowehekebaacieneroreie acca sick 96
Gorrelanon ol WVarGell, TOLrimaplOw..os avo cps s, oia's cpasckeua erersielerelsiaveislalaaetevsuciars orcas 97
WA TSS tied CO METLDLIOEN cee erevatesave &. svalersims Gy ous) oven: sins gua. avauetelalovahaiereraie eres lanetalafenatetetete sparese's 97
WWintstlen Oreck. TOMMaAtlOls ciccveccicieceirs sip cere svete nieve ake Wisi evecsto) ctonapelereleccieleeetalet suers 97
Correlation of VWViiustle’ Creek; formations; + 4. soc. ccle cosine oor siee calaie ey 07
NVIRITESDULE TORMAMOUTS cas ee he oe Ste ce Coe a eine creole een sence et nte Saree cre 97
Lis ig O Lg FO 100 ake RL AON ee OA i ok Aa eae Re aH Abed SORE A eco yl 98
Worrelation*or Witten formation: : + is's sacs seh ss eo OAS 98
Wioodway, formation vscs'.c0s2se 8s ee hee sk oie se eyes easels seats wees sa tae ee ee 99
Yellow Branch member of Poteet formation: 652.265.004.000 Tea eo ease 99
5. The Central Basin of Tennessee, Wells Creek Basin and High Bridge, Kentucky. 99
Central) Basin: of Tennessee: .sise css sd ses secs esd bac G5h e telteeeee ces eu elets 100
Muriceesboro- formation: :s'sicec ass ssac ee UIO. Nisa. VORA... 100
Correlation.o: -Muriréesboro. formation. so. ..isneesose tsb. Nas. . 100
IPHGECS LOSIMALIONY gnc s ns, yusex sb.vee sou ceeCleeeeeidel Same. A, AOU OER WIS, ws 100
Correlation.o: Pierce, tormation. ........ eewausod coe ated Aloo. os. 100
Beye GERARD eau scien 0.0/6) sia 's uo a6 0 'p0, oRPOEIIMRISOL,. MORIA Mt BOLERO els cis. IOI
Correlation a: Jidley: LOrmiation «sss ses +9 2 + 010 9.a'eien sheiabittetene saat S See IOI
Perm eeRE FQN HAUION co. cc hc syc.0'e tic 6 2's otaaghbanuet aay? amteretrrsidld & bays ganeeabe edie ch’s)s« IOI
GCorrelationjor Mebanon) formation. = ss 2esicrsie baie oie a's; 2 cielo ol oleretbvouspts areiaiethveiavere 102
Carers torino (otiginaiy Carters. Crecic) isc sin dimieatne As damn Pmctayeveatle-s \ 102

CHrrelamonmor Cables TOLMALION 7.) ties cles) dctels, ciao cisiais.sia <levsaicleleleisievers sere 103

Vili SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127
Page

(Hermanas wielcrs LimeStOHG «o oo.2¢ occ dodo see cou ais o.da an Sika bietttelaia a fataley Wis deahehs 103
Gorrelation of “Kimmswick”. limestone. .:« « « «00% «+ «side Mae. Qiateha.d oldie « 103
Bermntace- formation tiie udieisies ac dvia'seleSidiseiece o's adn e so SOMIMEE Mis, le sional, 103
Wells Greek Basin ois ccc caadcce aes OSU ITIRE EI. IM, TOI. MG the: 104
High: Bridge, central - Kentucky s2¢4-cce04 2 P20 TUT, SUES. A. TRIE Taal alae 105
Gamp Nelsonfortnation : cccd2 caesar teccece sa cae soa SOUR BIR ts Males. 105
Goerrelationof Camip-Nelson formation iis. 210 0. ie. a NOL eds s« | 505
Oreronforiaation luidaa'oins a oo vee USAR. ODOC ATTA, Mele Relate. TIM bine 106
LABOR HIORHAALION Vs as cine sl TROT, BIC. LO. 4 SOUR). eles Malte bea 106
Gorrelation of ‘Tyrone formation. «6 «JQ sUiaes Dt bdlé “dds eet elaa Ricci.

6: Ghe: disturbed! areavat. Kentland: Indiana js sas ed de25 cca sd ontlite Clee soles s.c1cheiere 106
Correlation of stratasof Kentland ‘areas tise 2 He az vols vac. aces dehonlee aosta te et overete 107
7) ier HETSSISSIP PE Walley Pelee ese eee odes and aa UREN DORIS a 108
Upner Whssissippt Vatley freee. 2 2 PORPIIOD, UIs 2 TRE Oe 108
St "Peter sandstones: /2écsi.c0ecsae0 sec sagecarss. PORAIOS, RO. 108
Plattevillesformation <2 ffs 2560 Fe Fors VOTE SE Se Peete ciels tetera 108
Glenwood member of Platteville formation................ cece eee eee 109
Pecatonica member of Platteville formation. : 2562520... 0. bec ec cee cence 109
McGregor ‘member’ of Platteville formation.) P03 120. (0. 220, Se 109
Mifilin' member of - Platteville formation: : << 22635233 . SPS ADSI 110
Macnoliay member of Platteville formations so:5222 2. S28 P2005. Sea. 110
Quimbys Mill member of Platteville formation...............c0e ec eee eee 110
Gorrelationof Platteville formations sss225 700 es Oa 110
Decorah formation “s2seedss shes boeceooonederonsiosse LO es Rae 110
Spechts Perry mémber ‘of Decorah: formation: : sz ::22. 00) 2022). Ss, 110
Gormelavon*of-Spechts Ferry member ies Se Ue aan III
Guttenbere member ‘of Decorah formation see ee deca eels III
Csarrelation" SF} Gutteubers “niermiber ices pg t eee ee ee 112
Loremenber ‘Or mecoraln 1Ormatione. te cece eee cece oe tec cee eee octet 112
Correlation ormlono members 2s Seite er oe tae tele eiee oes seretele dentuserhe 112
GOSSELEODIMIAUIOM Metre ic cic ee srociee cieels (so sistarciers sft oo are ociais oats aiers echt einer 113
Upper Mississippi Valley formations not in general use...............eeeeeeee 113
Wowell Park member of Platteville formation. :.....0...+0.0-6+s0+cceepe 113
IMMITMEAMOMS MtreSTOMEY. 2 o's asd cisls'erss.ov0\cle scverete cis: bo ae eis eese) etolelegelorenckoye ae ne kaeane II3
BelGityGOLOMMte: LODMIA TOM ais <a. 55 ceciterers ic ei ane avec, bke Bobb bake Gale Glaeser 113
Maddie INISsIssinpt Valley cis ss cis.ce 6 3 o's 500.4 e:sce 0.9 olbiorsias sip eera nt cand ee eee 113
AGE ALO Ip RRL CIedS LIES cms eye scheiossaicvore or ieichaveisiovs eraiaranetelnisie arene ane epepaiegsitce sxciv ees 113
ROG Mevee: TOPMAION <5 io.cr. sys b-aiae/0'e 6 ssajorevoraeleien tics ie iets cys mice eres II4
IPIBEEIN O LOUD A ras's ois ia ss ys\alsie/aiea.ieys 6.9 -0°% a/s'6 6) oaiaig orelels ois oie MO RORETS eae ere ere II4
Bloomsdale formation |. .2 =. -<siad byeniqgends bieteds Wes aeulegeuy oleae. eentie ee II4
Becett formation t. okie dws oisje:id dacs oontial/ds snenomse lt? Seeniene) dopeine asnete II4
Ineo ae Cig: Ch). a Se ee es II5
Gorrelation of Hager formation. «.. <oic.s.s0.9:< 2.0 Seer bis eee teem ete II5
Mire FOTIA OM: «oe cc ensesiecees sal cmkae? «Ghat SPE tas fea Ree sehr sa II5
Hook meniber of, Macy, formation s's 6s’. + ocee scene s.00 SRMIDAWR Rs dete « 115
Zell.member/of/Macyformation........cvibkwicl. eee ae. Sop oe 116
Gorrélatioaiof . Macy. formation, «.. 6... /s,0.s eidss.aieelemie ae SRE REM eee 116
Barahart formation iii 6 sina sca akc tas as OUIOE A FO IO 116
Gorrelation-of -Barnhart- formation: :: ss: << <4ss0% ca. Pores ta ioe weistele 116
AUT Chent fed PERE 2 FEE he Re ss OO es ere ere me ate ee nists 117

Gorrelationsot Atiburncherts or. 2. Feit ee eee emerson tea omer 117

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 1X
Page

NorthermbAckatisas {UL US Ui. cw awsic ec ne ge eam wan» MRR MeieIsialia oeiele nine syepenedies ig iy
Everton-Jasper. forriationy 220 <<... elec e'eiein eas GaN ROMAN ho ee a Risi tla e «oe 117
Correlation of Everton-Jasper formation......+++-++e+seerereresereceees 117
Bless 1 gio ae Ls v0 Winn ay 9 se Sn IDENT OES epee Mie oe eye Fes e+ 117

8. The Arbuckle and Wichita Wauntaiac, Oklahoma. itis riwsskehs «wilemsiee +e 118
Joins: formation ea yscse. eases veers ess enone selenite ye[tes% 118

Oil Greek FommmtionG vss og. sees a see tak aa py eee saben T° vine te * > 119
Mekush formation os eh 55 <cunegeey see sees ssN ss yh TORE NTC eee o + 119
Tulip Creek formation, .......<ss.2.+ 95s. ssemebinbeec et elteean sooo* 120
Correlation of Tulip Creek formation..........+eeseeeereeeeeertrereee 120
Bromide Formation. ov lols. «sees sia e seen enseasens ts: aeaebpe gy this * > * 120
Mountain Lake member of Bromide formation. ......+-++++++esseeeerrees 120
Pooleville member of Bromide formation.........+++eseseeerecreeerretes 121
Correlation of Bromide formation.........+.+eeeereeerseeeectsrssetetess 123

Wale TOLMIALION G4 sues Vel CRles ote save se oe eines we ehem hae NeeRarne oYn eG oe 2 123
Womble (Stringtown) formation of Arkansas and. Oldahoma.).,...sjefce > => == 125

g. The Black Hills, South Dakotas sso. ss% ss sc» gavatpleinsee ein sene® at biaisbiele te © © = oe 125
WY Hike WOOG AOC TALON 1/005 seis slo: 80.0 0m eines pine Se are ciniaselerain ely’ miotuis, ici = © © 125

10. The Great Basin—Nevada and California........s.esseeeereeesretereresceces 125
Antelope Valley and Toquima Range........-sseeeeeseeeseecrecree resets esse 126
Popomipyeroup J0leleee eek ess s ese e sss pase mt eee meaGs Van th ners 6555 126
GPeled OBO LLCO CO eth sees ess 56504 vhs ss yee CBs ab baie st o> 127
Pioche! District, Nevada (0.5 0450. .c0s seed. ccc c tte ge meee sa ss ae esas ckpes 129
EP ceET IL SORMACIOMUGS Lc cad ucs 6uee Shh ache wks e "Fines oa. Sibsoes § ate o iaieis/0'/* 129
California seis. PERO ORR ood Signa skins tsibe hs rs isin bat pie cases 129
Miarcble MOrmMAuOn GTi sss ccc sek ess Fon be aes ols ayes oh aan ae See 2.04) - 129
Barrels Sprite formations .)6.c5. 550+ ose00 bobs e ses Bae te A Ga Spaces: = s 129

Rr HOrmatUlisiin Wedheeee cc cecaatve ese res es oe e ora ets seg siee oss aaah > oko sos >, 1g0
bese bee NUEALITES ET OUNRR Tce ice L else ie sos ca eas aaaeas oe acer ges * 130
Niorihcasterm Utaly Cee ete LLL S ee eles ee sees mais see aes s pos cree ce * 130
Se Peake GUAT EZItecn NEL a Tes Dek lee tee ss be eee sae wae eae tae mec tt 9 130
Peepion Vi) “Phe Waseiict cto CC Sem Ps i ial cae ois sie a tye 8 cae mie te a cee alc 28 131
General discussion of the fossils... 0.2... cece eee eee eee een cece nce c cece cers 131
Concept of family atid genus: i) iif silicic eee eee eee ce epee neem nese recess 131
Shel geretite \ATONR SCENT SEAL ELLTEI EEL tlie tessa ssp a es Sapa sge scapes 131
TALES Tae NORTE TRUE SHES ASTI SNES Poetics seca tas ae es sas 0 132
serene PATIO ORSDELEPTEDES II SE ST Soh eer es ees sew get sae tee 78s 132
PPE DEREL E, PESUME TRONS eee eee eee ae aaa ea tae 133
Annotated list of genera and species........ 2.5. c cece cece e eect etree tees nets nce 138
bclacey WGastrocailiane tease hess athlS ch ligh sith Sel a meee sce ew ess asses 187
Superfamily Dictyoninacea : 232.22. 022s. ssh beets esse eee ge een eens ee ger ees 187
Paniily) Micromitridae’): 2. iss. kstsss cise i i ees ase ce ee ee tastes 187

Oe oe eo Re lac ang aM RES IIE Se a SC ICICI SCC cA I ae 189
Gupenimily @bOlaces els s; 2s fst Ass singe Teh eee Sees sae g ress: 189
Bagig Obolidacwt nt Oese Sheek tsar Teste steers me se coe sos ss aes ° 189
Suibiannly OPOlAae’: ses 555i82 sh TI2 sss eevee eee ares oan ges ss oes 189
Subfamily Lingulellinae: ¢2.:s...s2 6 eee eres. nee geese ele ase ees 195
Subfamily Acanthamboniinae ........-...se sees eee cece e rete tence eees 2iI
Subfamily ‘Glossellinae «: is... .ci cite ccs e sete cess e eee e ees c cece ce es 213
Superfamily Trimerellacea ........:..0eee seers reese eee eects eset se ceeees 229
Family ‘Trimeceliidae: os: 2 iss 2sia52 si: 5. DOSES a aes ee cles ele one * 220
Family Lingulasmatidae::..:.2:2s2.222 55. beer reece eee cece a cee ce rene 232

arly Paterabidae 1)... oteees esse sige enneneceeesoee es saweske ese ee 236

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Page

Supesiamily Acrotretacea . occ oun 0ojee cece ee sa roieie's » neil = teeiblalcleias)aisleletahtiae 5s 245
Berita ACE OEEGEUAAG pi eychsie's @ Biniuinalv-silene w fae doin ol SPORE Whete 5 aeRO a 245
Subtamily Acrotretinae 2. ..5/c)f Uelseihels sicelSaig oO SLO ale dials SUM AB eile led 5 0 245
SuneriamilySiphonotretacea <a sxc conde sc ves evaceu dv se esheets Tears s 263
Baszoily , Siphonoteetidac. situa ial a SURI. HE 4 OG, MIG RRR ch 263
Superfamily, Discinacea: <6 66666 coset te ds ood tae Sse fe AI UAE, 270
Panuly Drematidaesc nsec ic od ied tec ee oc ad see Ue Demo i e a 270
Praramt by DISCUS + ce en' oo ao sic of oleh oleic dl dathatet ujeldateteict. IUD ian dalle eR yee 275
Subfamily Orbiculoideinae |< «os oe es cee de dc ORO, Poe Gites 275
GeberrainriyeNeranideen ic Cod Ack ek ees Woe ee oe eee a a mee ae elon hee eeemee 282
Raesthy se canta (i oh ake fete Oe hte Anes sn. CORR, ne 282
Patan Paar mermnceue att ted Mts 4 Se! Sos ns. 0 cae e oe © ecu, Bl@in simisiaie mehr ig WRT mane aiagete as Re 292
Be pOtner (et hOiieais ye Osos cle wes sie ada s guide nome eames sag ae eames mr elon eee 2902
SOREIaEn i MORTHACCAS So cc davididde doses cas ean «8 ae a em ameie ® koe me amie 292
Rime TOG UINAG a ci cc Oc ta pola acceee Swen eee oe neha a sae eae 292
SPT ERIE ce tue e ode Siore's sive a einie ao alah a sir ts wiaasteia sie sea Syeiernan 293
Spiny ue UCOntnINAG) | TAS GSS SAR Sen 5 acct tg reais 333
Maia MELeSperCnOriGae te Se oe oo ict ve osc ee asngaeie nee aniotale tages ot alae 336
Ramilyg, Orthidiellidae. sis. icciesiaret ave chorea tlane 'c,0 3) evapo tous onan aus ipmie aie ere einteretans 338
Pamnly ELeSHeroriuitdae: cc jaecc ose oen as oicie mans ms 8s s¢ + Nee wn e'sg al tea er 343
pubieiily Flesperoreninde 952° odode ain: o'ee's Gal ease eee els hat emma mee 343
SubraimilyGiyptorthinae o.s/.irres-qeverterere sista ics cae ee cies ties teers aioe tae 361
Piaeatas NMOL TOR MOAE oc ba.cs sate sind 0a Sere 9 6 Oma inare ibs dems Gruen eee 301
UMAA UY: (PPLE AC 2.2 esis cece miaress ge a how wilde lath ine e's ens oo ware a ats oe ee ee 303
Picatinny PectOreidaa <5 iso faia's & aula lesion Oaks bik + Na ane pce Coe Rea ee 446
pupeamily (PIcetorthinaG, os nck Gewese as cons recom es aaeke acne wae oe ee oe 446

BF IS ERIGAICG 's. cia Scie ua sales sO SMORO REO ain o's oY? sinh Spomee Gaaes Uae OEE 491
BUPETAEE MoMA DGNITOIGEA ia aie fs atisddcewnas oe wuine dy bas 6a Same 1a heaie oai ewe SII
SupetiamslynC litambonittacea: /.6,c i serecels ore Sretcinietca et peters ote cise bile eee SII
I Sic LITT AR Bio fifo? fel gb 61 bo = ae aN SDR A Si AT 511
SAE SITOCCHIINAL. Vic i sort os biertare biewe Gino Salty CV EIe omer Mme ne 512
SubtamslyPolytoechinag ed .<.c'.s acisterto sicsepia teers Soe ee ee ee ee 512
Batatiy, OuUtambontidae \. 6's sois\<4+awaaemtcn sos © ppabasiowaue caminnae aah aae us 516
SIAC -PATELCIASINAEINAG os as cera s krereasd Ble ole we abate ie gore edie eee 516
Agni yO VOLdAEtiererd ays wie sgcecleco aie Goh GA Oe BREE SEL ORE Eee 526
Perinat SP LAMOSIACEA «6 os). bo... vd a elves oblate eee planien atl ieee 529
UENCE ARCSIATIAGS 05's sc <a, bos oye. dn.8 dha Wi oiatae Ae A AR ata 5 tysttalwle cei 520
SSUDOIMIET, NU RIEECIIIOIGEA ie as di.e oiale dno ¢ uo soa aun Rongelenl Witiens Madd ea ac Mae 559
PIGHeCIAidily SVMLTODINACEA: os. so < as os 64 are o'5)s bag che ale sm taleee pete nei 559
Peamety | SO VNELODMODSIOAS © 5... 4 s0:50'c 0:4 dis 5.0 a cae Meera Ieee 559
Pamty ETEVICAIMICTIONS v6 0 a cisiou siiey d04ohis ¥ CERES Ee Onl eae. ote 560
EaeMAy, MOAMOTCUICGE 5 cs a's cwinie cide a darg ad te Oe CRN CREE m RemeieeAaD Oui 562
POG AtEEy CAMETCUIIAG . . iiais.do's 6 0. 'o6 5’ mide is ee mm aed a aoe 562
PMotatily StCHOCAMALINAG . 2.66. seco se cccccnes + ogee aeatiesh «445 602
PAnIy PALAStVOPMINIGAC sco. advise t's soo co sik Gemetioeteh ad kinase ne ties 604
Suprdimily PATASTEODUININAG 2. oss «soc. cmnmabhbens Be ulbelttagh aaiaes 604
atte POrAtnpOrttlage 2's. oes. oo-05 4 5 garden Ee, ee cde oa 608
SBOtGer: PEMEAIEPOICED oo. sais ac e's 92.04 005 oy 2 BUR ERRU eS Wee cia wine 611
BUGRe raul y PP ORTAMETACES 3.5 occ soso sso die Qe ees atime qauaehe 611
Panuly’ Patallelelasmatidae oo. ...5..6eccesdccem Be ee mete yo OID 611

Superfamily Rhynchonellacea 2.06.65... 5.2.04 ene teneatee oF ee en 617

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER xi

Page

eatery E SCROLL VCO ciciee salsa cisiov ans ses cok cues sa daiee asineeasersnennes 617
Sseieoiniityr PTOtOrHyMentGae, co's eslsss se vie sd alate se a sree © e:6.0.0.0 se warn ene 617
SHDPATIE YO ATICISEPOLINVHCHSHAC 3.5 5c tics aidla'oia's si tis,sajsicisiovaieie a eee ne cie suas § 618
Bamily Riynchotcematimae sz 2 .tt hs cece oe Wee tes esis ce ccetesenencneeennees 628
eT PIE DICOCY.CHGAS Weveiaic/s cere aiasasrarepntaetavetatate oietsl later eiereitrai sree ieveise wisi erelete oe 657
Brera APOE Ly TAC NCEA id's dis nrs & oem Slate nl inlsra Si eicibialeia We )h)a aarela)s « ede woes 658
Family Orthoshyncbulidaeniwntiok 1! tee c enicig Mose. cece eee ce sans 669
RTI RIETNETIE HENLE VICE cca cterels: nisin svais walle ei Ga ata 8 Se vraLi’ a) 4: tease Shea aimee AR aah nies al ioe 669
Be ataat i CAVED WIAD: a5 ails Whee o-0ce «vain s,cuete time yee se uk ase halecr = ace trn nee eras 669
Sail y, LVCOSMEMIAG cates Me ease cea e rads sane Seems t eesti cece 669
Side WGMASSNAe’ aad cor eee oes. Se tata Mey ewace 2s F cas hoek moet es 690
MUMCEraMiy SUWMESACOD sn hacud, sess ferret te ee ere te taka st ots mere 693
Pantie, VCInsNiGae wocrese tts c« aces seer TCE te rashes feue meetin te ners 693
SRSCGEE StRMPEMIIEUOMUCd Ys ce wc ces te reat fe cate cee Ste mea Ne «ala sae ae oe 697
Supetiamily, Plectambonitacta Ooo. Soc sce cae ass Foie cha as make eset se 607
POY MEA UCAS fies cst owa hace ts sone cet ame sete ete ss «cas wate ane Mercer: 607
Poin PIecCtaMOniudde: Watts sovek Serre ou oke ries Sees tee anemic ror es 699
Sie CICctCMGAe LMS sees et a fe eee nek nas vege coats oes tes 699
PMEY TCPLCSLMAG tc scores ce st Mel eee teas cet tee re eros ate colnra ree 700
SDIAELY SICEMECSIIMAAE CCA ans veined ac.ae ages acinete teat «mek ete c Teta 700
MAY CSOPMEAPININAG Sets sock eset ees ce ab ec setae Pits ckte ee ee 733
Bice, tA UVOOOETIOAE aera < os ac atla cuss jarele Cee eee ee eee 740
PMU Sev MMTI Cha SIA EIEAE: a aia ska aipuarsinidiata caw te mee Seasleisia tee cccla knee cette 742
INN AE A MeN IOI? oy 5.4 cn iis las 'a,ej3; 0, sis egw hg esas hee Gee eee ee eee ee ee 744
SuUMimiy FIeSDELOMIENINIGe 3.03.05 css o.cenc ees tects ee trer tees ee rate 744
Sinrmmiy Terenas Cole es eek tae eee oct eee coer etmet oe eer eeas 746
SSeAULY, ACeHLCMONMINS is. cae cog acatiaa Wea came nascar te eee eee s 763
PAREN (EAITNOAG. 5. scninca ngs 3 cad Goa Me tee Cette CMT Te On 764
BeGHly SOWEERVEMICAE. i's gic'e «60,5 ti od woe veces cee eee ee Oe eee 774
BSUbaraily SOWEFUVELINAG |. beac es ce cacse cs adesceer een eee 774
Surely Nenamponitiiae 32° wPlOG, REIS, IOIE TY, STN 813
PUitcile: SPtvCnOPly PHAGE ..5 lon cies bs aswae als se o4 ele ke sale ede Ne 815
MUPELLAMMYy SLEOPMOMICHACEA, 0c c.. 6 ccs elie ec cc ne cc Meee TN nee cin nee 820
Pataily (Leptaenidae’.. 0.5. Pore tees Ff amee Pa Bee ewes ERR I 820
Paminy CHeStianudae® oo sis. sacs coe e ccc e oss ee CART pee 859
Pataily Strophomenidae 6. ce. 5.0. REPRE b CUORIIOER Rie RI ae 866
Suborder Dictyonheligides See See Pe. MEO A, TROY BETA, SEDER E 047
Pamilya Bidiwaldadaeo wins POA L028, AL, PIP VON)., OI 047
Suuortder Palmanecloided so 2cs acces sce leccs cs cece c oa SHEAR Roe hs aetna ae 047
Rraperiamily PalimanelaCed Jos rc sss 2 Giese bras dv ole bivreia ARM UA SOR ot 047
Paniy Maumanellidae: oo. osc asa/s sc do ROE, RT, OORT 047
Pamuly ‘Qimiellidae | SAT 7h. SEAT RIPE . HOE 053

EP eMNUE Ys (PAUP TERIA 5 25's 5) i) a'nid. on (elie ecae wi Wl ieeecnta o/s eine MOR OM ROE 064
Proritily’ TICrOrenidae: sce .cdisicin sos. onic c ROUTE, Rise. hho! 076
Sumamily ‘Harknessellinae ... ...d.0heiae). .eahvocrmen: Memon: 976
Pantily MMoOporeiudae . ose ves ces «cos coh ORUTIIGe F. RNY. Sh eer, 979
Pamiily) SchizOpROridae 6.66. aya oe o0.6. oe oisiid aialc'g SRR ce OTE, 085
SHIPMAN © SHCEEAO MOT INI a 6 oie case asses sb alee o'o oo dldia.o 4 ale ae OOOO 985
Grethts ae SPECIES WMCEE secs nec e ee ok ee oe 2. eer ee RlRinaLy 1006
OOS fh lal SM age ads Ln TS Pe Ear Leg it seER aa Giana So) 1007
Ee ets ee ge TK NG 5 a/c) Oak ins wierd g.ate abr wield mbes 6 eae oR MIRE 6.4 IOIQ

Heo) bln AN sg al So lS) ol

2

23.
24.
25.
26.
27.
28.
20.
30.
31.

32.

ILLUSTRATIONS
PLATES
(All plates in Part II, following page 1246.)

Lingulella, Obolus, Pseudolingula, Westonia.

Ectenoglossa, Lingulella, Obolus, Spinilingula.

Ectenoglossa, Glossella, Glyptoglossa, Lingulella, Pseudolingula.

Ectenoglossa, Glossella, Lingulella.

Glossella, Lingulella, Pachyglossa, Pseudolingula.

Ectenoglossa, Lingulella, Pachyglossa, Plectoglossa, Pseudolingula.

Lingulella, Obolus, Pachyglossa, Palaeoglossa.

Ectenoglossa, Lingulella, Obolus, Plectoglossa.

Acanthambonia, Dictyonites, Glossella, Lingulella, Obolus, Palaeoglossa, Torynelasma.
Dictyonites, Eoconulus, Lingulella, Palaeoglossa.

Glossella, Lingulella, Obolus, Pachyglossa, Schizotreta, Spinilingula, Trematis, Westonia.

. Leptobolus, Lingulasma.
. Glossella, Glyptoglossa, Lingulasma, Obolellina, Orbiculoidea, Schizambon.

Schizambon, Siphonotreta.

. Schizambon.

Conotreta, Spondylotreta.
Ephippelasma, Conotreta.

. Acanthambonia, Conotreta, Paterula, Rhysotreta, Scaphelasma, Spondylotreta, Toryne-

lasma, Undiferina.
Schizocrania, Schizotreta, Trematis.
Orbiculoidea, Schizotreta.

. Schizambon, Schizotreta.
. Acrotreta, Craniops, Obolellina, Obolus, Petrocrania, Philhedra, Schizambon, Schizo-

treta.
Elliptoglossa, Lingulops.
Elliptoglossa, Obolellina, Paterula, Pseudobolus.
Acanthocrania, Petrocrania.
Acanthocrania, Petrocrania, Philhedra.
Acanthocrania, Pachyglossa, Petrocrania, Schizotreta, Trematis.
Acrotreta, Conotreta, Lingulella, Pachyglossa, Schizotreta, Torynelasma.
Orthidiella, Trematorthis.
Orthidiella, Orthidium.
Archaeorthis, Orthidium, Pleurorthis.
Cyrtonotella, Hesperorthis, Pleurorthis, Rhysostrophia.

33-36. Orthambonites.

37.
38.
39.
40.
4I.
42.

43.

Mimella, Onniella, Orthambonites.
Nothorthis, Orthambonites, Taphrorthis.
Cyrtonotella, Nicolella, Taphrorthis.
Cyrtonotella, Taphrorthis.

Cyrtonotella.

Nicolella, Orthambonites, Ptychopleurella.
Glyptorthis, Ptychopleurella.

44-47. Glyptorthis.

48.

49.

Eridorthis, Glyptorthis.
Glyptorthis, Hesperorthis, Orthambonites, Productorthis, Ptychopleurella, Taphrorthis.

xii

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER xiii

50. Atelelasma, Cyrtonotella, Desmorthis, Eremotoechia, Glyptorthis, Hesperorthis, Ptycho-
pleurella.

51-54. Hesperorthis.

55. Scaphorthis.

56. Multicostella, Productorthis.

57-59. Dinorthis.

60. Multicostella.

61. Chaulistomella, Dinorthis, Multicostella.

62. Multicostella.

63, 64. Chaulistomella, Multicostella.

65. Chaulistomella, Dinorthis.

66, 67. Chaulistomella.

68. Campylorthis, Chaulistomella, Multicostella.

69. Campylorthis, Chaulistomella.

70. Chaulistomella, Valcourea.

71. Camerella, Chaulistomella, Dinorthis, Multicostella, Plectorthis, Valcourea.

72. Chaulistomella, Dinorthis, Valcourea.

73-75. Valcourea.

76. Chaulistomella, Valcourea.

77. Eremotoechia, Tritoechia.

78. Anomalorthis, Atelelasma, Eremotoechia.

79. Atelelasma.

80. Atelelasma, Kullervo.

81. Atelelasma, Plectorthis.

82. Atelelasma, Cyrtonotella, Hesperorthis, Orthambonites, Pionodema, Productorthis, Pty-
chopleurella.

83. Desmorthis, Plectorthis.

84. Plectorthis.

85-91. Mimella.

92. Doleroides, Mimella, Plectorthis, Skenidioides.

93-96. Doleroides.

97, 98. Skenidioides.

99. Ancistrorhyncha, Elasmothyris, Eremotoechia, Genus and species undet., Kullervo,
Mimella, Onychoplecia, Oxoplecia, Skenidioides, Tropidothyris.

100. Onychoplecia, Oxoplecia, Triplesia.

101-105. Oxoplecia.

106. Camerella, Oxoplecia, Parastrophina, Porambonites.

107. Porambonites, Salonia.

108. Camerella, Glyptorthis, Idiospira, Oxoplecia, Perimecocoelia, Porambonites, Taphrorthis.

109. Camerella, Idiostrophia, Rhysostrophia.

110. Camerella, Liricamera.

111. Camerella, Perimecocoelia, Stenocamara.

112. Camerella, Rhysostrophia.

113. Camerella, Idiostrophia.

114. Camerella, Perimecocoelia.

115. Camerella, Parallelelasma, Stenocamara.

116. Camerella.

117. Camerella, Parastrophina, Perimecocoelia.

118. Brevicamera, Camerella, Parallelelasma, Parastrophina.

119. Brevicamera, Parallelelasma, Parastrophina, Perimecocoelia, Protozyga, Stenocamara.

120. Didymelasma, Neostrophia.

121. Camerella, Dalmanella, Hesperonomiella, Macrocoelia, Onychoplecia, Parallelelasma,
Triplesia.

122. Liricamera, Plectocamara.

xiv

123.
124,
125.
126.

127.
128.
129.
130.

SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Plectocamara.

Dorytreta, Oligorhynchia, Rostricellula, Sphenotreta.

Oligorhynchia.

Ancistrorhyncha, Atelelasma, Chaulistomella, Dalmanella, Oligorhynchia, Phragmorthis,
Plectocamara.

Ancistrorhyncha, Oligorhynchia.

Ancistrorhyncha, Drepanorhyncha, Mimella, Orthorhynchula, Rhynchotrema.

Ancistrorhyncha, Rostricellula.

Lepidocyclus, Rhynchotrema, Rostricellula.

131-137. Rostricellula.

138.
139.
140.
I4I.
142.
143.
144.
145.
146.

147.
148.
149.
150,
152,
154.
155.
156.
157.
158.
159.
160.
161.
162.
163.
164.
165.
166.
167.
168.
1690.
170.
171.
172;
173.
174.
175.
176.
177,

Oxoplecia, Plectocamara, Rhynchotrema, Rostricellula.

Rostricellula.

Idiospira, Protozyga.

Cyclospira, Protozyga, Zygospira.

Cyclospira, Hallina, Protozyga, Zygospira.

Cyclospira, Fascifera, Hallina, Laticrura, Protozyga, Sphenotreta, Zygospira.

Laticrura.

Hirnantia, Howellites, Laticrura.

Cyclomyonia, Dalmanella, Diorthelasma, Eremotrema, Laticrura, Paurorthis, Phrag-
morthis.

Reuschella.

Genus and species undet., Phragmorthis, Reuschella.

Fascifera, Laticrura, Paurorthis.

151. Paurorthis.

153. Fascifera.

Pionodema.

Fascifera, Paurorthis, Pionodema.

Pionodema.

Cristiferina, Dalmanella, Onniella, Paucicrura, Pionodema.

Cristiferina, Dalmanella.

Cristiferina, Onniella, Paucicrura.

Cristiferina, Eremotrema, Paucicrura.

Cristiferina, Dalmanella, Onniella.

Dalmanella, Paurorthis, Pionodema.

Aporthophyla, Eichwaldia, Ingria.

Aporthophyla, Toquimia.

Taphrodonta.

Apatomorpha.

Palaeostrophomena.

Glyptambonites, Palaeostrophomena.

Isophragma, Palaeostrophomena, Sowerbyites.

Isophragma.

Glyptambonites, Isophragma.

Hesperonomiella, Paucicostella, Ptychoglyptus, Taffia.

Glyptambonites, Limbimurina, Macrocoelia, Paucicostella, Ptychoglyptus, Strophomena.

Ptychoglyptus.

Glyptambonites.

Glyptambonites, Palaeostrophomena.

178. Titanambonites.

179-181. Sowerbyites, Titanambonites.

182,
184.
185.

183. Sowerbyites.
Bimuria, Eoplectodonta, Isophragma, Palaeostrophomena, Sowerbyites, Titanambonites.
Hesperomena, Syndielasma, Titanambonites.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER XV

186. Ancistrorhyncha, Dactylogonia, Eremotoechia, Leptellina, Ptychoglyptus, Reuschella,
Zygospira.

187. Leptellina.

188. Leptellina, Leptelloidea.

189-191. Leptellina.

192. Bilobia, Eoplectodonta.

193. Anisopleurella, Bilobia.

194. Bilobia, Bimuria, Dactylogonia, Palaeostrophomena, Titanambonites.

195. Anisopleurella, Bilobia, Idiospira, Leptellina, Toquimia, Xenambonites.

196-202. Sowerbyella.

203. Eoplectodonta, Sowerbyella.

204, 205. Sowerbyella.

206. Sowerbyella, Titanambonites.

207. Eoplectodonta.

208. Eoplectodonta, Leptaena.

209. Eoplectodonta, Goniotrema, Sowerbyites.

210. Bimuria, Christiania, Isophragma.

211. Bimuria.

212. Bimuria, Leptaena.

213. Craspedelia, Hesperinia, Isophragma, Ptychoglyptus Rhipidomena, Strophomena.

214. Christiania.

215. Chonetoidea, Christiania, Sowerbyella.

216. Dactylogonia.

217. Dactylogonia, Murinella, genus and species undet.

218. Dactylogonia, Rhipidomena.

219. Dactylogonia, Leptellina.

220. Dactylogonia, Limbimurina.

221. Bellimurina, Christiania, Laticrura, Limbimurina, Petroria, Phragmorthis.

222. Bellimurina, Limbimurina, Strophomena.

223. Bellimurina, Cyphomena, Limbimurina, Murinella, Pelonomia.

224. Cyphomena.

225. Dactylogonia, Teratelasma.

226. Dactylogonia, Murinella.

227. Murinella.

228. Cyphomena, Dactylogonia, Leptaena, Murinella.

229. Furcitella, Hesperinia, Holtedahlina.

230. Macrocoelia, Platymena.

231. Glyptomena, Macrocoelia.

232-234. Macrocoelia.

235. Glyptomena, Macrocoelia.

236. Macrocoelia, Opikina.

237, 238. Opikina.

239. Macrocoelia, Opikina.

240-244. Opikina.

245. Glyptomena, Opikina.

246. Glyptomena, Opikina, Pionomena.

247. Macrocoelia, Opikina, Rafinesquina.

248. Pionomena, Rhipidomena, Strophomena.

249. Macrocoelia, Opikina, Rhipidomena.

250-253. Rhipidomena.

254. Rhipidomena, Strophomena.

255-262. Strophomena.

263. Strophomena, Trigrammaria.

Xvi SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

264. Strophomena.

265. Furcitella, Pionomena, Strophomena.

266. Platymena, Rafinesquina.

267. Colaptomena.

268. Dinorthis, Fascifera, Oligorhynchia, Opikina, Plectocamara, Ptychoglyptus, Sowerbyella,
Stenocamara, Xenambonites, Zygospira.

269. Eoplectodonta, Hesperorthis, Paurorthis, Plectorthis, Reuschella, Sowerbyella.

FIGURES
Page
1. Map showing location of sections in the Appalachians...............ceeeeeecccces 37
2. Diagram illustrating facies changes in East Tennessee and southwest Virginia from
north to south. The diagram is not made to scale because of difficulties in draw-
ing the facies shifts in the rapidly thickening wedge south of Friendsville....... 4O
a ane same facies pattern with formation! names... 2. ...0% 20sec oes cee 40

CHART

1. Chart showing correlation of formations and members from which brachiopods are
mentioned, described,’or Mlustrated . «0 csics05 0 scsesne0es.00 0» once pate 130

Charles DB. and Mary Waux MalcottiWesearch Fund

CHAZYAN AND RELATED BRACHIOPODS:
PARAL) ly Rel

By G. ARTHUR COOPER

Curator of Invertebrate Paleontology and Paleobotany
United States National Museum

(WirTH 269 PLates In Part IT)

Section I. THE FORMATIONS
INTRODUCTION AND STRATIGRAPHIC SETTING

The brachiopods forming the subject of this monograph are a natural sequel to
those of the Ozarkian and Canadian periods. While Dr. E. O. Ulrich and I were
preparing the monograph on Ozarkian and Canadian brachiopods it became evi-
dent that post-Canadian brachiopods were as little known as those on which we
were working. It was, therefore, planned to prepare a second monograph under
the joint authorship of Ulrich and myself on the brachiopods of Ulrich’s Chazyan
which included all the rocks between the top of the Canadian and the Lowyville.
Ulrich’s division comprised a very imposing sequence of rocks in the Appala-
chians and many other parts of North America. To his Chazyan was added the
Black River group of rocks and its correlates as Ulrich understood this group.
The brachiopods from the Black River were clearly closely related to those of
the Chazyan and, like the Chazyan, were little known. The plan was to regard
the lower Trenton, as understood by Ulrich, as the upper limit for the study.

Many unforeseen circumstances transpired to delay the work, and in the mean-
time Dr. Ulrich’s health declined to such an extent that he withdrew from the
project.

While the studies were progressing and the collections were being brought
together, views were changing on the stratigraphy of the Chazyan and Black
River divisions. G. M. Kay, in New York and Ontario, was revising the Tren-
ton and elaborating the Rockland division which proved to be of wide distribu-
tion. At the same time, Byron N. Cooper, then of the Virginia Geological Sur-
vey, and C. E. Prouty, of the Tennessee Valley Authority, were establishing in
Tazewell County, Va., a detailed section that was to become a standard for the
area. These studies and my own investigations in the Appalachians showed
clearly that the Chazyan of Ulrich actually included rocks from Chazyan to Tren-
ton and that the Black River of Ulrich was in large part of Trenton age. In
spite of these disclosures it seems unnecessary to change the name of this mono-
graph. The formations now have a far different alignment from that which UI-

SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 127, PART I

2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

rich gave them, but the brachiopods include Chazy forms with related Black
River and Trenton types.

BACKGROUND FOR THE STUDIES

In 1939, I had my first introduction to the Appalachians with Dr. Charles
Butts and Dr. Josiah Bridge. Dr. Butts, who knew the Appalachians more inti-
mately than anyone before him, kindly consented to show Bridge and myself
their intricacies from Pratt Ferry in Alabama, where the Appalachian structures
plunge under the Coastal Plain, to Winchester, Va. We saw the facies changes
involving the Athens and Arline formations and the reefs of the Effna at Porter-
field Quarry. This first expedition was followed by others, many of them with
Dr. B. N. Cooper.

My association with Dr. B. N. Cooper began about 1941 when the latter called
at the National Museum to confer regarding some of his fossils from Virginia.
Cooper was then studying the Ordovician sequences to learn of deposits of chemi-
cal limestone. These studies had made him familiar with many interesting and
important sections. The conference resulted in the discovery that the two of us
independently had arrived at the same facies picture for the Middle Ordovician
stratigraphy in the Appalachians of Virginia. It was then decided to join forces
and apply the new ideas to the sequences southwest of Virginia in Tennessee,
Georgia, and Alabama. We made seven expeditions between 1941 and 1951.

Additional background was obtained in several expeditions to the Arbuckle
Mountains, and two expeditions to the Antelope Valley of Nevada where an in-
comparable Ordovician sequence is exposed. Dr. Bridge and I visited Chazy in
1938 to study the typical sequences along Lake Champlain. Alwyn Williams of
Wales and I examined numerous sections in central Pennsylvania, covering the
ground described by G. M. Kay. The same party examined sections in southern
Wisconsin, Minnesota, and Iowa. All these expeditions added to our knowledge
and increased the collections.

BUILDING THE COLLECTION

The collection on which this study is based is a large one and was derived
from many sources. The initial stages of building consisted of selecting good
specimens from the large mass of stratigraphic material obtained by various mem-
bers of the U. S. Geological Survey. Part of this material was collected by E. O.
Ulrich, and another large part was brought in by Charles Butts during his years
of mapping in the Appalachians. Other contributors were R. S. Bassler, G. W.
Stose, Josiah Bridge, and Edwin Kirk.

The largest part of the collection was obtained by me in various trips to the
Appalachians and the West. Each year specific localities of promise were visited
and revisited and rare fossils tracked down so that adequate material for de-
scription was finally brought together. It was mainly through my efforts that
much silicified material was brought in, and later processed. It was this material

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 3

that produced so many of the small and unusual fossils such as those from Pratt
Ferry, Porterfield Quarry, and Friendsville.

Gifts to the Museum.—I am grateful to many of my colleagues for gifts of
important material :

Dr. G. M. Kay, Columbia University, presented specimens from Ontario and
New York; Dr. B. N. Cooper presented a fairly large collection from the Appa-
lachian Valley in Virginia; Dr. C. E. Decker presented to Dr. Ulrich an exten-
sive suite of collections from the Arbuckle Mountains; O. C. Cole, of Kenyon,
Minn., gave the Museum many brachiopods from the Ion and Prosser forma-
tions of Minnesota; Dr. G. Winston Sinclair presented several collections, one
from Paquette Rapids, Ontario, another from the vicinity of Montreal, and an
interesting lot of Strophomenas from Quebec and Ontario; Dr. Robert R. Shrock
presented an extensive suite of specimens from the cryptovolcanic structure in
Kentland, Ind. ; Dr. Helgi Johnson, of Rutgers University, and Dr. Cecil Kindle,
of City College of New York, gave small but choice collections of Table Head
material from Newfoundland; Dr. C. W. Merriam presented the Museum with
an extensive collection of early Middle Ordovician fossils from the Antelope
Valley of Nevada; Dr. Lawrence D. Whitcomb presented specimens of the new
genus Limbimurina from Pennsylvania; Dr. L. F. Hintze presented a few speci-
mens from the Confusion Range, Utah; Ray C. Gilbert made a present of a few
exceptional specimens from the lower part of the section near Lusters Gate,
Blacksburg, Va.; Dr. Robert B. Neuman presented a collection from the Row
Park and New Market formations in Maryland and Pennsylvania; a superb lot
of fossils from the Arbuckles sequence was donated by Dr. A. R. Loeblich, Jr.,
now of the U. S. National Museum staff.

Borrowed material_—Early in the work on this monograph the officials of the
Carnegie Museum lent the large and valuable collection of Chazy brachiopods
accumulated by the late Dr. P. E. Raymond, who made pioneer studies on this
group of rocks and its brachiopods. Peabody Museum, through Dr. C. O. Dun-
bar, lent material from the Mingan Islands. Dr. G. M. Kay, Columbia University,
lent a few rare specimens from New York and Ontario.

PREPARING THE FOSSILS

The collection on which this monograph is based consists of many superb
specimens. The material was prepared by several methods. Throughout the
United States and Canada fossils frequently occur in a silicified state. In the
Appalachians, many localities exist where the fossils can be removed from the
rock by means of hydrochloric and acetic acids. Indeed, in some localities such
as the Cahaba Valley, Ala., and the region around Friendsville, Tenn., fossils
abound in the residual soil resulting from the deep weathering of the Little Oak
and Arline limestone. In these places the silicification is often somewhat coarse
in texture but is, nevertheless, very good.

Muddy limestones frequently yield good silicified specimens. In etching such
material, great patience is required because decalcification of the rock yields a
mass of mud, often fairly hard, from which the fossils must be taken. It requires

4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

considerable care to pick or wash the mud from delicate and brittle interiors. The
Lincolnshire limestone, such as that at Shiloh Church on the north side of Clinch
Mountain in the Pressmens Home (T.V.A.) Quadrangle, commonly produces
quantities of mud when decalcified, and the shells are brittle and sometimes frac-
tured. They are nevertheless of the finest quality but require great care in
handling.

Recognition of silicified brachiopods is generally not difficult because the speci-
mens are usually weathered into relief on surfaces. The shells, too, often show
silicious rings or the blue-gray color of chalcedony. When selecting material for
etching, it is a good plan to look for blocks or take pieces of ledge rock showing
specimens well scattered throughout the mass and on all sides of the block.

Inarticulate brachiopods may be prepared by dissolving limestone in acetic
acid. This is a method described by W. C. Bell (1948). Generally, inarticulates
are not sufficiently common to give an abundance of specimens from limestone
pieces. The locality at Pratt Ferry, Ala., is unique in furnishing a great variety
of inarticulates. Some inarticulates have been prepared by using dilute hydro-
chloric acid. This is true of much of the cobbly limestone material occurring in
the lower part of the Edinburg limestone. Paterula, Elliptoglossa, Conotreta,
occasional linguloids, and Schizambon have been removed from this part of the
column by hydrochloric acid as well as acetic acid.

Chemical means can also be used to prepare molds of the interior and exterior
of brachiopods. This can be successfully accomplished on specimens that are
not silicified and that are preserved in a silty or fine sandy matrix. It is best to
apply the acid with a brush or medicine dropper so that the solution of the shell
can be controlled. It is usually necessary to harden the newly exposed matrix and
also newly revealed parts so that the mold will not be injured. Numerous speci-
mens from the Oranda formation were prepared by this treatment.

Most of the interiors of unsilicified specimens were prepared with needles
ground to a chisel edge. An excellent utility point may be made by beveling a
needle of appropriate gage at various angles to the long axis, depending on the
work to be done. This beveling produces a broad face with sharp edges for
scraping and also a sharp point for digging. It is best to scrape away matrix
against the shell rather than dig it away. Careful scraping leaves no unsightly
scratches.

A number of interiors were prepared by roasting the specimens in a blast lamp
and then letting the shell cool. This treatment calcines and softens the shell to
such an extent that it can be scraped away by a beveled needle. The shell gen-
erally turns white from the heating and makes a convenient color contrast with
the matrix. Careful scraping will produce molds of the interior that are quite as
good as those obtained by dissolving the shell away. The success of a brachiopod
study depends almost entirely on the information derived from the interior ; con-
sequently, no pains should be spared to preserve this part.

ACKNOWLEDGMENTS

Many friends and interested persons have been of great assistance in the
preparation of this monograph. Inasmuch as the work originated as a joint un-

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 5

dertaking by a member of the U. S. Geological Survey and one from the U. S.
National Museum, I have enjoyed favors from many of my colleagues in both
organizations. Dr. Alexander Wetmore, former Secretary of the Smithsonian
Institution, made possible my numerous field expeditions which furnished the
major part of the collection. The studies were supported by Dr. R. 5. Bassler,
the head curator of the department of geology in the National Museum. My
colleague, Dr. A. R. Loeblich, Jr., helped immeasurably as field companion and
donor of a large and exceptionally fine collection of Simpson brachiopods.

Dr. J. B. Reeside, then chief of the section of stratigraphy and paleontology,
made it possible for me to have and use parts of the collections of the U. S. Geo-
logical Survey made by Dr. E. O. Ulrich and Dr. Charles Butts. Drs. T. B.
Nolan and Harry S. Ladd assisted in field trips to the Southwest and West by
allowing the use of Survey equipment.

The early stages of the work were greatly facilitated by a grant from the Geo-
logical Society of America through the Penrose Fund. This grant was made in
1937 to help me in organizing, preparing, and photographing specimens. Dr.
Preston E. Cloud, Jr., now chief of the paleontology and stratigraphy branch of
the Geological Survey, who was the recipient of the grant, prepared and photo-
graphed most of the materials studied prior to 1938. I wish to express my thanks
for this grant and my appreciation of the diligence of the grantee.

In making acknowledgments, I cannot overlook the contributions of my two
mentors in Ordovician stratigraphy, now deceased. It was originally planned
that this should be a joint undertaking with Dr. Ulrich, but because of the long
delay in getting under way Dr. Ulrich voluntarily retired from the project.
Nevertheless, I will always remember the hours of instruction received from
him. To Dr. Charles Butts I owe much for his inspired guidance in the Appa-
lachians. Dr. Butts knew Appalachian stratigraphy as no one before him, and
he led me and my colleagues to many places where collections could be made and
information obtained. I am also grateful to Dr. Butts for the many discussions,
often heated but always illuminating, on problems of Appalachian stratigraphy.
Dr. Edwin Kirk, of the U. S. Geological Survey, helped with information on
sections in Nevada.

Many friends outside of Washington helped me in the laboratory and field.
Dr. G. M. Kay furnished information on many localities. Dr. William E. Ham,
Oklahoma Geological Survey, spent several days in the Arbuckles with me; Dr.
C. W. Wilson, Vanderbilt University, spent several days in the field and fur-
nished important information from his wide knowledge of the Central Basin of
Tennessee. Thanks are due the late Dr. Percy E. Raymond, of Harvard Col-
lege, for making it possible for me to study the type specimens of Southern
Appalachian brachiopods described by him and Dr. Bradford Willard. Similar
acknowledgments are due to Dr. E. M. Kindle and Miss Alice Wilson, both
former officials of the Canadian Geological Survey. They kindly placed at my
disposal type specimens of many of Elkanah Billings’ species for study and pho-
tographing while I was in Ottawa in 1938. Thanks are extended to Dr. W. A.
Bell, Canadian Geological Survey, for permission to prepare the interior of one
of the types of the brachiopod Petroria figured on plate 221, E. Dr. C. W. Mer-

6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

riam, U. S. Geological Survey, furnished much information on stratigraphy: in
Nevada.

Thanks are extended to two companions of several field expeditions, Dr. Byron
N. Cooper and Dr. Raymond S. Edmundson, both former members of the Vir-
ginia Geological Survey. These expeditions with Dr. Cooper and our associa-
tion during the 6 months he spent at the National Museum were informative and
inspiring.

Dr. Raymond S. Edmundson, now of the University of Virginia, and a col-
league of Dr. B. N. Cooper in the mapping of the Virginia chemical limestones.
accompanied us on several expeditions. His brilliant and careful structural and
stratigraphic work was of valuable assistance; he helped lay the groundwork of
the stratigraphy.

LOCATION OF TYPES AND ABBREVIATIONS

Most of the types illustrated in this monograph belong to the U. S. National
Museum. It was desirable to illustrate specimens borrowed from other institu-
tions to show structures or species not exhibited in National Museum specimens
or present in the National Collection. All the type repositories are designated
herein, as follows:

A.M.N.H. American Museum of Natural History.
Carnegie Mus. Carnegie Museum.
Columbia Univ. Columbia University.
G.S.C. Geological Survey of Canada.
M.C.Z. Museum of Comparative Zoology, Harvard College.
U.S.N.M. United States National Museum.
Y.P.M. Peabody Museum, Yale University.

In the descriptive part of the monograph all numbers are those of the National
Museum unless otherwise designated. In some cases, U.S.N.M. is prefixed to
numbers where ambiguity might otherwise appear.

In lists, names marked by an asterisk are doubtful identifications.

NOTES ON THE CORRELATION CHART

Any chart depicting correlation of formations is really only a report of prog-
ress that approximates but never portrays the real truth. The chart presented
herewith (chart 1, facing p. 130) is certainly not a final picture of this part of the
Ordovician. Many parts of it are not in clear focus and it will take much study
and more collecting of fossils to eliminate these fuzzy portions. Throughout all
the Ordovician covered by this chart, much paleontological work still needs to
be done. One of the important weaknesses in our knowledge of brachiopods is
the small amount of information that has been gleaned on this group from the
Table Head series of Newfoundland. The correlative rocks in Nevada are also
in need of attention. With the appearance of this monograph the Appalachians
will be better known, but many parts of them have not been studied and still
remain virtually unknown.

PART 51 CHAZYAN AND RELATED BRACHIOPODS—COOPER v4

Another quality of the correlations recorded herein must be stated to the
reader so that he can better understand the difficulties involved. Correlations
based on a single group of animals seldom if ever give the true story of relation-
ships and correlation of strata. Correlation by complete faunas is the only sound
method because different parts of a fauna may be retarded or advanced and
only the sum total gives the truth. The present chart is based mostly on evi-
dence deduced from a study of brachiopods, and most of the relationships herein
depicted were detected by comparison of brachiopod faunules. However, when
Dr. B. N. Cooper was making his studies of the trilobites of these same rocks at
the National Museum in 1946, we were in close touch. Correlation by trilobites
closely parallels that based on the brachiopods. A careful check by bryozoans,
which are very numerous in the Appalachians and elsewhere, is a natural sequel
to the present studies.

In preparing the chart I did not completely overlook the value of other fossils,
but, on the other hand, I was well aware of the unreliability of some “guide fos-
sils.” Reference is made to Cryptophragmus antiquatus, Tetradium cellulosum,
and Maclurites “magnus.” Cryptophragmus is now known to have a long range
and thus not to be an absolute indication of the Lowville or Pamelia as hitherto
believed. JT. cellulosum is known from Trenton rocks as well as Lowville.
Maclurites is long-ranged and is not an infallible guide to the Chazy, as con-
fusion in Pennsylvania between Lemont and Hostler shows.

The chart contains five new stage terms which are designed to divide this part
of the Ordovician into related parts. These stage terms are here proposed by
myself and B. N. Cooper. Older stage terms, such as Chazyan and Black River,
are no longer of use because these have been so defined that they do not describe
the stratigraphy, or, as in the case of the Black River, the interval represents
only a part of what we regard as a natural grouping of faunas. Grabau’s (1909)
usage of Chazyan included the Black River, which we regard as more closely
related to the overlying Rockland than to the Chazy group below. The Ulrich
(1911) conception of the Chazyan was for the interval between the Lowyville
and the top of the Canadian (Beekmantown or Knox dolomite), which is far
too inclusive. The name Bolarian (Kay, 1948, p. 1402) includes two divisions ;
Hatterian and Hunterian, but these, too, are unsatisfactory to show the relation-
ships as B. N. Cooper and I understand them. The Hatter formation, whose time
designation is Hatterian, appears to be the same as Hunterian if, as shown in this
monograph, the Hatter is equivalent to Ridley. The Hunterian includes Low-
ville, Chaumont, and their equivalents, but besides them Kay adds the Witten
formation. The Witten, with its Pionodema and Doleroides, is placed by B. N.
Cooper and myself as a correlative of the Rockland. Furthermore, the Rockland
fauna is closely tied to that of the Chaumont, as I understand those fossils. Thus
Bolarian is unsuited to depict the stratigraphic situation as understood herein.

It was not a simple task to find satisfactory names for the stage terms here
offered, but the sequences named are well exposed in the vicinity of the geo-
graphic locale selected.

Whiterock stage.—This name is taken from Whiterock Canyon in the Monitor

8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Range in the south center of the Roberts Mountains (1°) Quadrangle, Nev. The
rocks of the interval are well exposed in parts of the Antelope, Monitor, and
Toquima Ranges shown on the same sheet. The brachiopod fauna taken from
rocks deposited during this stage is characterized by numerous orthids, the early
strophomenids, plectambonitids, and the decline of the Syntrophiacea. Correla-
tive rocks appear in the Arbuckle Mountains of Oklahoma and the Table Head
series of Newfoundland. Exotic blocks containing fossils related to the Table
Head of Newfoundland have been found in the boulders of the Mystic con-
glomerate and from a little-known formation near North Cambridge, N. Y.
Equivalents of these beds in Europe are not clearly understood, but some related
forms have been taken in Norway and Estonia.

Marmor stage-—The name for this stage is taken from the point called Mar-
mor, just northeast of Friendsville on the Concord (T.V.A. 138-SW) Quad-
rangle, Tenn. The reference section is along the railroad to the east of Marmor
and extends to the adjacent Louisville (T.V.A. 138-SE) Quadrangle. This stage
includes the Chazy group of rocks and its correlatives.

Ashby stage-—The name for this stage is taken from a road intersection on
Hogskin Creek, in the northeast quarter of the center subquad. of the Maynard-
ville (30’) Quadrangle, Tenn. In the Hogskin Valley the formations Elway and
Lincolnshire comprise this stage and are well exposed. In fact part of the Lin-
colnshire and its shaly Hogskin member are especially well displayed. Kay
(1948, p. 1402) places the formations of this stage in his Chazyan, but I believe
that this is not justified on paleontological grounds. The Elway-Lincolnshire
contains many Chazy elements, but it also contains brachiopods, such as the
coarse-ribbed dinorthids, which are unknown in the Valcour or any other part
of the Chazy group. It is believed that the rocks deposited in the Ashby stage
are younger than those of the Marmor (Chazy group).

Porterfield stage-——This name is taken from the Porterfield Quarry, 5 miles
east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle, Va., and its environs.
This stage is characterized by the prolific and exotic fauna that floods into the
Appalachians and blots out and absorbs the Lincolnshire fauna. The Porter-
field fauna is strongly linked to the Stinchar-Balclatchie fauna of the Girvan of
Scotland. It is characterized by Christiania, Palaeostrophomena, Isophragma,
and a host of other restricted genera. In the vicinity of the type area the sequence
of rocks deposited during this time is not thick, but to the east the section be-
comes enormously thick. The fauna dies out in the upper part of the Benbolt and
is replaced in the Wardell by familiar “Black River” types. In northern Virginia
the Porterfield fauna occupies most of the Edinburg formation and, in modified
form, characterizes the Oranda formation.

Wilderness stage.—This stage takes it name from the Wilderness Trail (U. S.
Highway 58) that parallels the bold Cumberland Front in western Virginia.
Rocks deposited at this time are well exposed for several miles east of Cumber-
land Gap and are revealed in their entirety along the railroad at the switch near
Hagan, Rose Hill (T.V.A. 161-NE) Quadrangle. This stage includes the old
Black River plus the Rockland and their equivalents. The fauna is especially

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 9

characterized by abundance of Opikina, Strophomena, Pionodema, and Dole-
roides. It is succeeded by the Trenton with its flood of cryptolithid trilobites
and more modern brachiopods, many of which appear in the preceding stage but
fail to make a prominent impress on the fauna. The Oranda fauna is believed to
have lived in Wilderness time and represents the fading stages of the Porterfield
fauna, which lingered on in eastern areas probably now obliterated by the intru-
sions of the Blue Ridge and Great Smokies and the metamorphism of sediments
now underlying the Piedmont.

Trenton stage.—This stage is modified by removal of the Rockland which has
mostly fossils derived from the underlying Black River and Witten. Deposition
of the Sherman Fall is thought to inaugurate the Trenton stage.

The chart also gives the range of the important genera described. A star
indicates that the genus appears as far as known at present, at the point where
the star appears, and then ranges to a point beyond the upper limits of the chart.
An asterisk behind a generic name or group of names means that the genera
do not range beyond the point where the asterisk occurs. A number of genera
so marked are confined to the Pratt Ferry formation. Numbers are placed at
the top and bottom of the chart to make the finding of the generic name in any
column easier. In the annotated list of genera and species appearing in Sec-
tion II each genus bears the number of the column in which it appears.

GEOGRAPHIC AND GEOLOGIC SETTING OF THE FORMATIONS

In the following pages are set forth brief descriptions of the formations from
which were taken the brachiopods forming the subject of this report. The geo-
graphic setting for the formations is given according to the region or realm in
which they are developed. In the Southern Appalachians the stratigraphy is so
complicated and the formations so numerous that it seemed advisable to arrange
the formations alphabetically and reserve the regional discussion for the com-
panion paper to the present volume being prepared by B. N. Cooper and myself.
That discussion will consider all the Southern Appalachian formations from
Pennsylvania to Alabama in detail. Most of that information need not be given
here, but for the sake of completeness the formations and their faunas are
described and listed.

My field work has not been sufficiently extensive to cover all the regions from
which Chazyan and related brachiopods have been taken. Some of the discus-
sion is therefore based on the literature. This is true also of the fossil lists. I
have not seen all the species listed under some of the formations, nor does the
National Museum have collections from all the formations, but the names are
recorded nevertheless.

In discussing the formations, it seemed unnecessary to repeat any material
already appearing in the “Lexicon of Geologic Names” (Wilmarth, 1938). This
useful work contains the definitions of all formations described in the United
States up to January I, 1936. Formations named after that time are herein
described more fully. Although the definitions in the “Lexicon” are complete
and some information on correlation is given, the book contains scarcely any

Io SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

paleontological information. Inasmuch as the present work is concerned wholly
with brachiopods, stratigraphic discussion and correlation are based almost
wholly on them. The bearing on correlation of fossils other than brachiopods is
mentioned only in instances in which brachiopods tell an inaccurate or equivocal
story.

The lists of brachiopods appearing under the formation names have been ob-
tained from the studies recorded herein and from lists published by other authors.
In some instances listed identifications are so fantastic that the writer has placed
an asterisk before the name to show that the identification is incorrect. For
example, some Richmond species have been identified in the Simpson group.
In many instances, however, I have not seen specimens recorded for all the
formations and can only let the names stand even though considerable suspicion
of incorrectness may attach to the identification. This naturally detracts from
the value of the lists, but in any study of paleontological literature it must be
realized that listed forms must be used with great care. This is especially true
of the lists presented by the nonspecialist stratigrapher, who still feels that he
can identify any fossil.

In spite of the deficiencies noted above, the lists do contain the names of all
species I have identified or described. These also appear in a master list at the
head of the section on the brachiopods, but it will not be possible to check the
species appearing in the stratigraphical section with those in the brachiopod part
because the master list contains only species considered in the text.

The formation lists are notably incomplete in some instances. All the forma-
tions have not been evenly collected, and the need for some formation names
became apparent only at a late stage of the work. Consequently, lists for the
Sequatchie Valley formations, for example, are not entirely satisfactory, and the
same situation exists with most of the marbles. Specimens from the marbles are
usually difficult to identify because of exfoliation of shell, lack of preservation
of muscle scars, and generally poor interior preservation; consequently, the age
of the marbles was obtained by blocking them in between well-studied beds above
and below. Furthermore, the faunas of the marbles are very much the same in
generic composition, a remarkable example of facies restriction, which makes
the identification of an isolated marble a difficult proposition. At present the
marbles cannot be taken out of their sequences and satisfactorily identified or
their age determined. They must some day be studied individually.

Most of the lists suffer from incompleteness. This study has taken a long time
and a huge collection was examined. Nevertheless, the collection on which it is
based represents only a minute fraction of the fossils that must be collected and
studied in the future to determine the true story of Ordovician stratigraphy and
paleontology. It is at best a good beginning.

The brachiopods discussed in this monograph come from the following regions:
Newfoundland.

The St. Lawrence and Ottawa Valleys and adjacent areas.

The Champlain, Mohawk and Hudson Valleys.
The Appalachians (Pennsylvania to Alabama).

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER LE

The Central Basin of Tennessee, Wells Creek Basin and High Bridge, Kentucky.
The disturbed area at Kentland, Indiana.

The Mississippi Valley.

Arbuckle and Wichita Mountains, Oklahoma.

The Black Hills, South Dakota.

The Great Basin.

Formations in Utah and California.

I. NEWFOUNDLAND

Along the west coast of Newfoundland fossiliferous Ordovician rocks are ex-
posed at many places. These were examined by Logan (1863, p. 870) who
separated them into four divisions, lettered K-N. According to Schuchert and
Dunbar (1934, pp. 63-69) these four divisions form a natural group for which
they proposed the name “Table Head series.”

TABLE HEAD SERIES

The lower Table Head (K, L) is composed mostly of limestone somewhat
massively bedded in the lower part but the main mass consisting of thin-bedded
limestone weathering to rubble, the sequence measuring 811 feet. Middle Table
Head (M) consists of dark limestone and interbedded black shale, a total of
270 feet. The upper part of the series (N) is composed chiefly of black car-
bonaceous shale 300 feet thick.

Brachiopods occur in all parts of the sequence in more or less abundance.
The following genera and species are known:

Acrotreta gemma Billings
Aporthophyla aurora (Billings)
Archaeorthis electra (Billings) = A. new species
Camerella parva Billings

C. tumida Cooper

Ectenoglossa nympha (Billings)
Ectenoglossa sp. I

Idiostrophia perfecta Ulrich and Cooper
Idiostrophia plicata Cooper

Obolus cyane (Billings)

Obolus sp. 1

Onychoplecia kindlei Cooper
Onychoplecia sp. 1

Orthidium fimbriatum Cooper
Pelonomia delicatula (Billings)
Pleurorthis imbecilis (Billings)
Pleurorthis sp. 1, 2

Porambonites sp. 2

Ptychoglyptus ? kindlei Cooper
Rhysostrophia sp. 2

Correlation of Table Head series—The facies of the Table Head series
is that of a black shale and limestone environment and is strongly suggestive of
the Liberty Hall facies of the Edinburg formation or the Whitesburg formation
of Tennessee. The trilobites of the Table Head are similar to those from the

12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Virginia and Alabama formations with the exception that certain forms occurring
in Newfoundland, such as the trilobite Ectenonotus, have never been seen in the
Appalachians. The brachiopods apparently form a homeomorphous series when
compared to those of the Appalachians. The small orthids, for example, prove
to belong to Archaeorthis. Hesperonomiella seems to be present and numerous
others not yet described that look like higher genera but when examined on the
interior prove to have relationships to types that lived in late Canadian or in
Whiterock time.

In the present paper I have included only the few Newfoundland species for
which good material was at hand. Genera other than those here recorded are
represented. For example, Rhysostrophia is a not uncommon genus, but the
National Collections are not provided with good specimens.

The elements of the Table Head fauna are known elsewhere in Quebec, New
York, and Nevada. In Quebec some of the boulders of the Mystic conglomerate,
the youngest boulders yet found, contain many elements and even actual species
of the Table Head of Newfoundland. A small Rhysostrophia suggestive of the
Table Head one is present; Pleurorthis is common to both, as is Ptychoglyp-
tus (2). Also common to Newfoundland and Quebec are Idiostrophia and
Orthidium.

Genera common to the Table Head of Newfoundland and the upper Pogonip
of Nevada are: Idiostrophia, Orthidium, Rhysostrophia, Hesperonomiella,
Aporthophyla and Porambonites ?. The trilobite Ectenonotus is common to
Nevada, Quebec, and Newfoundland.

LONG POINT SERIES

This name is applied to the 1,500 feet of section exposed at Long Point in
southwestern Newfoundland with thin-bedded, greenish-gray, calcareous, rippled
sandstones and siltstones and zones of greenish shale in the upper part; greenish-
gray calcareous shale interbedded with limy sandstone and sandy limestone in
the middle part; and thin-bedded sandy limestone with oolitic limestone and
intraformational conglomerate and some heavier beds at the base. Brachiopods
listed from the series are:

Camerella aff. C. volborthi Billings
Dalmanella rogata (Sardeson)
Dinorthis aff. D. iphigenia (Billings)
Glyptorthis bellarugosa (Conrad)

G. cf. G. crispata (McCoy)
Hesperorthis aff. H. tricenaria (Conrad)
Rafinesquina alternata (Conrad) = R. trentonensis (Conrad)
R. aff. R. deltoidea (Conrad)

R. aff. R. minnesotensis = Opikina
Sowerbyella sericea ? (Sowerby)

S. aff. S. undulata (Salter)

Triplesia extans (Emmons)
*V alcourea sp.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 13

Correlation of Long Point series.—The listed fossils suggested a Trenton age
for the Long Point series. Glyptorthis bellarugosa, Rafinesquina trentonensis,
Dinorthis aff. D. iphigenia, and Triplecia extans are now regarded as good indi-
cators of the Rockland formation or Upper Wilderness stage or possibly slightly
higher in the Trenton. Valcourea sp. is the only brachiopod listed that is not
in harmony with a Trenton age, but this one may not be correctly identified.

COW HEAD BRECCIA

The Long Point series is overlain by the Cow Head breccia of uncertain thick-
ness, ranging from 350 feet to probably more than 1,200 feet. This formation
consists of a mass of ragged blocks of enormous size and of several different
ages. No fossils have been taken from the matrix of the breccia, consequently a
definite age is not known. The blocks incorporated in the mass range in age from
late Cambrian to those of the Long Point series. The formation is thus definitely
younger than the Long Point.

HUMBER ARM SERIES

The Cow Head breccia is overlain by 2,700 feet of red, green, and black shales
of the Humber Arm series. The few graptolites and brachiopods, among them
Paterula amii Schuchert, found in the series are thought to be no younger than
medial Ordovician. However, Schuchert and Dunbar (1934, p. 98) conclude
that some late Ordovician may be present because of the enormous thickness of
the series.

2. ST. LAWRENCE AND OTTAWA VALLEYS AND ADJACENT AREAS

Areas of Ordovician rock exposure, including the stratigraphic interval em-
braced by this study, appear in seven general areas: The Mingan Islands in
the St. Lawrence River north of the west end of Anticosti Island ; Quebec City;
Montreal; along the Ottawa River in the vicinity of Ottawa and Hull; at the
head of the St. Lawrence Valley in New York and adjacent Canada; the sec-
tion at Coboconk, Ontario; and Manitoulin Island region on the north side of
Lake Huron in Ontario.

MINGAN ISLANDS

These islands form a group in the St. Lawrence River just north of the west
half of Anticosti Island. A sequence of Chazyan rocks called the “Mingan
formation” has long been known on these islands.

Mingan formation.—The maximum thickness of this formation is 155 feet,
according to Twenhofel (1938, p. 23) who described it in detail. The upper 116
feet are composed of limestone containing numerous fossils. Below these lime-
stones occur 20 feet of shale with some beds of quartzite and lime sands. The
basal 3 to 8 feet is composed of sandstone and conglomerate. Fossils occur in

I4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

all parts of the sequence. The brachiopods listed by Twenhofel and Whiting

(1938), with additions by Cooper, are:

Ancistrorhyncha ? vacua Cooper

Camarella ? longirostris Billings = Onychoplecia longirosiris (Billings)

Camarotoechia orientalis Billings = Rostricellula orientalis (Billings)

C. pristina Raymond = Rostricellula pristina (Raymond)

Dactylogonia extensa Cooper

Glyptorthis cf. bellarugosa (Conrad) = Glyptorthis sp.

Hesperorthis ignicula (Raymond)

Lingula huronensis minganensis Twenhofel and Whiting = Lingulella ? huronensis minga-
nensis (Twenhofel and Whiting)

Mimella ? minganensis Twenhofel and Whiting = Mimella minganensis Twenhofel and
Whiting

Petrocrania prona (Raymond)

Plectorthis ? piger (Billings) = Mimella piger (Billings)

Rafinesquina champlainensis minganensis (Twenhofel and Whiting) = Glyptomena cham-
plainensis minganensis (Twenhofel and Whiting)

Rhynchocamara varians (Billings) = Camerella varians Billings

Rostricellula triangulata Cooper

Schizambon duplicimuratus Hudson = Schizambon duplicimuratwum Hudson

Correlation of Mingan formation.—The age of the Mingan formation is with-
out doubt the same as part of the Chazy group of New York; the only question
is, with what part of the New York section does it correlate? The assemblage
listed has nothing in common with the older Chazy (Day Point) and is un-
doubtedly all of younger age. In common with the Crown Point formation of
New York, which overlies the Day Point formation, it contains Schizambon
duplicimuratum, Glyptorthis, Dactylogonia incrassata=D. extensa Cooper, Ros-
tricellula pristina, Onychoplecia longirostris, and Camerella varians. The only
definite link with the high Chazy (Valcour) is Hesperorthis ignicula, which is
common in the lower 50 feet of the Mingan section. The reader must be re-
minded that the Valcour fauna is not yet completely known, particularly the
portion in Quebec known as the St. Martin formation which contains many ele-
ments of the Crown Point as the Glyptorthis and Dactylogonia. Consequently
the correlation is best made with Valcour and Crown Point rather than with
Crown Point alone.

The fossils mentioned above as diagnostic of the Crown Point and Valcour
formations are also reminiscent of species in the Lenoir of Tennessee and the
McLish of Oklahoma. These formations are correlated (see below) with the
Crown Point and Valcour of the New York section. This, therefore, seems
the best assignment for the Mingan formation as well.

QUEBEC CITY REGION

The Lévis shales, on the south side of the St. Lawrence, underlie the village
of Lévis and extend for considerable distances along the St. Lawrence Valley.
In the vicinity of Lévis these shales contain several boulder beds in which are
limestone erratics of several ages. Generally these boulders have never been
dated as younger than late Canadian, but some of the species that have been taken

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 15

from them, when compared with brachiopods from the Mystic conglomerate, the
Table Head of Newfoundland, and the Pogonip of Nevada, suggest that the
dating should be with at least part of the Whiterock stage. Billings (1865) de-
scribes species dissolved out of silicified pieces from Limestone (boulder bed—
No. 2) which are suggestive of post-Canadian brachiopods. These are Orthidium
gemmiculum, Nothorthis delicatula, Trematorthis lévisensis, and Pleurothis tri-
tonia. None of these genera have yet been taken from the highest Canadian
(Black Rock).

Quebec City formation—Much of Quebec City rests on the Quebec City
formation which is in fault contact with the Sillery formation (Lower Ordo-
vician-Canadian) and the Utica-Loraine shales. The Quebec City formation
also occupies the west side of the Island of Orleans in the St. Lawrence River.
The rocks are hard, fine-grained limestones, dark shales, and thin limestone con-
glomerates. The thickness is not yet known and the structure and stratigraphic
sequence have not been determined. According to Raymond (1913a, p. 29),
pebbles in the limestone conglomerate are fossiliferous and contain Bilobia pisum,
the trilobites Tretaspis and Lonchodomas hastatus, and the sponge Nidulites.
The shales contain the graptolite Corynoides calycularis. These fossils suggest
the Rysedorf conglomerate of New York, the lower part of the Edinburg forma-
tion of northern Virginia, and the lower part of the Chambersburg formation of
Pennsylvania and Maryland. Paterula amii also occurs in the formation.

Through the kindness of René Bureau, Laval University, Quebec, I examined
collections of brachiopods and trilobites from the Quebec City formation. One
collection contained excellent specimens of Sowerbyites (S. sp. 1) and Valcourea
sp. 5 which indicate affiliation of that part of the Quebec City formation with
the Lincolnshire formation or the part of the Tellico formation that abounds in
Sowerbyites.

Another collection loaned by Dr. Bureau contained a fine large O-roplecia like
O. multicostellata and Paucicrura-like punctate shells. These suggest the lower
Edinburg and Chambersburg, but I was assured by Dr. Bureau that the Sower-
byites was younger than the assemblage with O-roplecia. Possibly the various
faunas come from boulders because the sequence in the Southern Appalachians
is the reverse of that in the Quebec City.

On the chart, the Quebec City formation is interpreted as similar to the Ryse-
dorf conglomerate and given the same age. From these few remarks it should be
evident that the Quebec City formation invites close paleontological and strati-
graphical study.

MONTREAL AND VICINITY

The lowest beds in the vicinity of Montreal of concern here are heavy-bedded,
hard limestones belonging in the upper Chazy Group. These extend from Mon-
treal to the vicinity of Hawkesbury, Ontario, along the Ottawa River. Little
sand is present in the Chazy at this place. The limestone becomes thinner and
thinner to the west and does not extend far west of Ottawa. It is believed that
limestone is at least partially equivalent to the sands and shales of the Chazy in

-

16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the vicinity of Ottawa. The sands thin eastward while the limestones thin to
the west.

St. Martin formation—Dr. A. E. Wilson (1946a, p. 17) selected Cap
St. Martin as the type section of the St. Martin member of the Aylmer forma-
tion. This type section is not far northwest of Montreal, and St. Martin is prob-
ably thus applicable as a formation name to the Montreal occurrences. Camaro-
toechia plena is abundant in some layers around Montreal and thus makes
correlation with the Valcour formation of the New York sequence possible.

Brachiopods from the St. Martin formation are:

Camarotoechia plena (Hall) = Rostricellula plena (Hall)
Clitambonites porcia (Billings) = Ptychopleurella porcia (Billings)
Dactylogonia sp.
Glyptorthis transversa Cooper
“Heberitella’ acuminata (Billings)
Hebertella borealis Billings = Mimella borealis (Billings)
H. imperator (Billings) = M. imperator (Billings)
H. vulgaris Raymond = M. vulgaris (Raymond)
Lingula belli (Billings) = Palaeoglossa belli (Billings)
Lingulella cf. L. huronensis Billings
Plaesiomys platys (Billings) = Multicostella platys (Billings)
Rafinesquina incrassata Hall

*Rafinesquinia alternata (Conrad). (Incorrectly identified.)
Rostricellula raymondi Cooper
Schizambon duplicimuratum (Hudson)
Zygospira acutirostris (Hall) = Sphenotreta acutirostris (Hall)

Pamelia formation.—Okulitch (1936, p. 127) reports a thin equivalent of
this formation, not over Io feet thick, consisting of dolomite and sandy limestone
with green shale partings.

Lowville formation.—This formation consists of 16 feet of gray, thin- or
thick-bedded limestone weathering dove gray, the layers separated by this shale
partings. Fossils are common and Okulitch (1935) reports:

Opikina transitionalis Okulitch
Rafinesquina grandis Okulitch = Strophomena grandis (Okulitch)

Chaumont formation.—Under this heading are placed rocks formerly called
Leray in the vicinity of Montreal. This formation consists of thick beds of dark,
light-gray-weathering limestone about 23 feet thick. The formation may extend
to the east to within about 35 miles of Quebec. Brachiopods reported by Okulitch
(1935) and others are:

Dinorthis sp.

Leptaena radialis Okulitch = Cyphomena ? radialis (Okulitch)

Pionodema sinuata Okulitch = Genus ?

Rafinesquina alternata (Conrad) = Opikina clara (Okulitch) ?

. clara Okulitch = O. clara (Okulitch)

. grandis Okulitch = Strophomena grandis (Okulitch)

. minnesotensis (N. H. Winchell) = Opikina minnesotensis (N. H. Winchell)
. transitionalis Okulitch = O. transitionalis (Okulitch)

. wagnert Okulitch = O. wagneri (Okulitch)

AAAAD

PART T CHAZYAN AND RELATED BRACHIOPODS—COOPER 17

R. williamsi Okulitch = O. wagneri (Okulitch)

*Rhynchotrema increbescens (Hall)

Strophomena corrugata Okulitch = Strophomena okulitchi Cooper
*S. emaciata Winchell and Schuchert
*Strophomena incurvata (Shepard)

No formations correlative with Rockland are known in the vicinity of Montreal.

OTTAWA VALLEY, VICINITY OF OTTAWA

Ottawa and vicinity have long been known for the interesting fossils described
from the Ordovician rocks that underlie the city and surrounding country. Here
an interval from the Lower Ordovician (late Canadian) through the Richmond
is exposed.

Aylmer formation.—This name was used by Raymond (1905, p. 362) for
the Chazy rocks in this region. Recently the formation has been divided into
two formations, one of shale and sandstone, the other of limestone, which are
at least partial facies of each other and would be better considered as members
of the Aylmer formation. The Aylmer formation extends from L’Orignal west
to Alumette Island, about 115 miles. In its westernmost localities the limestone
is not present.

Rockcliffe member of Aylmer formation.—This name is applied by A. E. Wil-
son (1946a, p. 17) to the lower part of the Aylmer formation, which consists of
predominantly green shale containing lenses of fine, gray sandstone. It is named
for Rockcliffe Park, just east of Ottawa. In places the basal layer is a con-
glomerate. This member has an average thickness of about 160 feet.

Brachiopods reported are:

Camarotoechia orientalis Billings = Rostricellula orientalis (Billings)
C. plena (Hall) = R. plena (Hall)

Hebertella imperator (Billings) = Mimella imperator (Billings)
Lingula lyelli Billings = Ectenoglossa ? lyelli (Billings)

Lingulella rugosilinea Cooper

Lingulella sp. 6

Mimella latistriata Wilson

Rostricellula wilsonae Cooper

St. Martin member of Aylmer formation—This member is named by A. E.
Wilson (1946a, p. 19) from Cap St. Martin, north of Montreal, where I give it
formation rank. The member consists of about 20 feet of gray or brown shales,
gray-green sandstones and impure limestones, and dolomites which weather to
a rusty brown. East of Ottawa, deep wells indicate that the member thickens to
150 feet. Dr. Wilson reports four zones in the St. Martin, the lowest containing
several species of Hebertella (=Mimella) with a few specimens of Camaro-
toechia (=Rostricellula) orientalis. In the second zone the proportion of the
two genera is more nearly equal; in the third zone R. orientalis becomes much
more abundant. The fourth zone abounds in Camarotoechia (= Rostricellula)
plena with R. orientalis.

Correlation of Aylmer formation—Raymond (1905, p. 362-364) has shown

18 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

that the Aylmer formation of the Ottawa Valley region is to be correlated with
the Valcour formation, uppermost Chazy. This correlation is chiefly based on
the common presence of Rostricellula plena in the Ottawa formation and the
Valcour of New York. Few other fossils are common to the two sequences
because the facies are quite unlike.

Ottawa group (or formation)

This name is taken from the Ottawa Valley and embraces a number of units
that were hitherto regarded as formations. Dr. Wilson believes that the fos-
sils indicating certain time units do not conform with lithologic boundaries of
the formations that had been previously defined. In order to make Ottawa stra-
tigraphy more practical and more easily understood Dr. Wilson recommends
abandonment of the formations that had hitherto been recognized: Pamelia,
Lowville, Leray, Rockland, Hull, Sherman Fall, and Cobourg. This problem
occurs in many sequences that have been refined by paleontological work, such
as the Southern Appalachians. Here a number of geologists have attempted to
divide the Chickamauga limestone on the basis of fossils, but shifting facies make
boundaries cloudy and the geologist uninitiated in fossils finds the separation of
formations difficult. This has inspired a recent effort to revive the name Chicka-
mauga as a formation. Inasmuch as one purpose of the present work is to portray
in detail brachiopod assemblages, I prefer to recognize the named faunas in both
the Ottawa and Chickamauga limestones, realizing at the same time that the
boundaries between divisions are in many cases uncertain.
Pamelia formation.—In the Ottawa Valley this formation is composed of
two divisions, the lower one characterized by its large proportion of sandstones
and sandy shales. Thin layers of dark limestone, some fine-grained and others
dolomitic, also occur. The upper Pamelia consists mainly of gray limestone and
beds of dolomitic material, separated by shale partings. A few sandy layers ap-
pear, but the upper beds are distinguished from the lower ones by a lesser sand
content. The division between the upper and lower Pamelia and between the
Aylmer underneath and the Lowville above the Pamelia are transitional and
difficult to determine. The two divisions of the Pamelia are estimated to attain
at least 69 feet in thickness. Fossils are rare in the Pamelia but one of the im-
portant ones is the trilobite Bathyurus extans Hall. Brachiopods reported by
A. E. Wilson (1946a, pp. 3-9) are:
Camerella panderi Billings = Idiospira panderi (Billings)
Lingulella narrawayi Wilson
Strophomena canadensis Wilson

*S. filitexta Hall

S. minuta Wilson
S. venustula Wilson

Correlation of Pamelia formation—The Pamelia of the Ottawa Valley has
many characteristics of the New York or type Pamelia and is probably related
to it. Although the Pamelia was placed in the Chazyan by Ulrich (1911, pl. 27)
its affinities seem rather to be with the overlying Lowville than with the Chazy.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER I9

This view was expressed by A. E. Wilson (1932) as well as others. The lith-
ology is completely unlike that of the Aylmer formation below, and the few
fossils known are quite unlike those of the lower beds. The disappearance of
the Rostricellula of the Aylmer sees the appearance of new types. Wilson records
a number of species of Strophomena which is a genus not yet seen in rocks de-
posited in the Marmor Stage. This genus, too, links the Pamelia to the over-
lying Lowville. As a matter of fact it is doubtful if the formation is really sepa-
rable from the Lowville here or elsewhere on a paleontological basis.

Lowville formation.—In the Ottawa Valley the Lowville formation is 20 to
30 feet thick and consists of the usual light-gray limestone with an occasional
shaly bed. It abounds in the coral Tetradium cellulosum, and the trilobite
Bathyurus extans is a common fossil. Brachiopods are numerous in the forma-
tion and have been listed by A. E. Wilson (1946a, pp. 3-9) as follows:

Dalmanella rogata (Sardeson) = Paucicrura rogata (Sardeson)
Doleroides gibbosus (Billings)

D. pervetus ottawanus Wilson = D. ottawanus Wilson
Eridorthis rocklandensis Wilson

Glyptorthis bellarugosa (Conrad). (Identification doubtful.)
Lingula narrawayi Wilson = Lingulella narrawayi (Wilson)
Opikina sinclairi Wilson

O. subtriangularis Wilson

O. tumida Wilson

Rafinesquina alternata plana Wilson

Rhynchotrema ainsliei (N. H. Winchell) = Rostricellula ainsliei (N. H. Winchell)
R. increbescens (Hall). (Identification doubtful.)

Schizocrania filosa (Hall)
*Sowerbyella sericea (Sowerby)
*Strophomena filitexta Hall

S. venustula Wilson

Zygospira recurvirostris (Hall)

Correlation of Lowville formation—This formation is evidently the same as
the Lowville of New York, but the list presented above contains numerous Tren-
ton species and types. In the Appalachians Zygospira is very rare prior to the
Witten (equivalent to Rockland), and typical Rhynchotrema increbescens is cer-
tainly a post-Lowville (probably post-Rockland) species.

Chaumont formation.—In the Ottawa Valley this formation had hitherto
been called Leray formation (see below). It is a heavy-bedded, dark-gray lime-
stone with some shale partings but little chert in its northern manifestation. The
formation is about 30 feet thick. A E. Wilson (1946a, pp. 3-9) lists the follow-
ing species:

*Camerella hemiplicata (Hall)

Dalmanella rogata (Sardeson) = Paucicrura rogata (Sardeson)
Doleroides gibbosus (Billings)

D. pervetus ottawanus Wilson = Doleroides ottawanus Wilson
Eridorthis rocklandensis Wilson

Hesperorthis tricenaria (Conrad)

Lingula obtusa Hall = Genus ?

L. rectilateralis Emmons = Genus ?

20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

L. riciniformis Hall = Genus ?
Microtrypa altilis Wilson

Opikina wagneri robusta Wilson
*Rafinesquina alternata (Conrad)

R. alternata platys Wilson

R. normalis Wilson

R. ottawaensis Wilson
*Rhynchotrema ainsliei (N. H. Winchell)
*R. increbescens (Hall)

R. intermedium Wilson

Schisotreta canadensis Wilson
*Sowerbyella punctostriata (Mather)
*S. sericea (Sowerby)
*Strophomena delicatula Fenton
*S. cf. S. dignata Fenton
*S. filitexta Hall

S. filitexta crenulata Wilson

S. filitexta obesa Wilson
. minuta Wilson
. mollis Wilson
. planumbona praecipta Wilson
. rotunda Wilson
. thalia Billings
. venustula Wilson

Trigrammaria trigonalis prima Wilson
Zygospira deflecta (Hall)
Z. recurvirostris (Hall)

HAHHHHY

Correlation and discussion of faunal list—This list is composed only of those
species placed by Wilson in the “Leray column.” Those species placed on the line
“Leray-Rockland” are added to the Rockland list because many Trenton forms
appear on the line that elsewhere are unknown in the Chaumont. Even with this
precaution the list above contains many Trenton forms that are not known in
the Chaumont elsewhere such as Paucicrura rogata, Sowerbyella punctostriata,
Rafinesquina alternata and varieties or subspecies, Strophomena filitexta, Rhyn-
chotrema increbescens. Despite these uncertainties the formation probably is the
equivalent of the Chaumont of New York.

Rockland formation.—This is the type region for this formation which here
consists of about 35 feet of heavy-bedded, gray, somewhat crystalline limestone
interbedded with shale at some places. The brachiopods are listed below; those
prefaced by a double asterisk are from Leray-Rockland beds where difficulty
was experienced in separating the two. A single asterisk indicates a doubtful
identification as in other lists.

Camerella hemiplicata (Hall) = Parastrophina hemiplicata (Hall)

C. panderi (Billings) = Idiospira panderi (Billings)

**C. volborthi Billings
**Crama trentonensis Hall

Dalmanella paquettensis (Sinclair) = Onniella paquettensis Sinclair

D. rogata (Sardeson) = Paucicrura rogata (Sardeson)
**Dinobolus canadensis (Billings) = Obolellina canadensis (Billings)
**D. erectus Wilson=O. erecta (Wilson)

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 21

**D. magnificus (Billings) = O. magnifica Billings
Didymelasma abruptum Cooper
Dinorthis brownt Wilson
D. iphigemia (Billings)

D. iphigenia minor Wilson

D. pectinella (Emmons)

D. cf. D. p. sweeneyi (N. H. Winchell) = Dinorthis cf. D. sweeneyi (N. H. Winchell)
D. regularis Wilson

**Doleroides gibbosus (Billings)

**D. pervetus ottawanus Wilson = Doleroides ottawanus Wilson

**Fichwaldia subtrigonalis Billings

**Glyptorthis bellarugosa (Conrad)
Hesperorthis tricenaria (Conrad)
Microtrypa altilis Wilson
M. ? nasuta Wilson

**Opikina ampla Wilson

**O, gloucesterensis Wilson

**O. hemispherica Wilson

**O, inquassa (Sardeson)

O. ovalis Wilson
O. platys Wilson
0. rugosa Wilson

**O, rugosa avita Wilson

**O, septata borealis Wilson

**O, sinclairi Wilson
O. subtriangularis Wilson
O. transitionalis (Okulitch)

**O, tumida Wilson
Platystrophia amoena McEwan
P. a. longicardinalis McEwan
P. trentonensis McEwan

**Plectorthis ottawaensis Wilson

**P_ pulchella Wilson
Rafinesquina alternata (Conrad)

**R. a. alata Wilson

**R. a, intermedia Wilson
R. a. plana Wilson

**R. a. semiquadrata Wilson

**R. a. transversa Wilson
R. hullensis Wilson

**R. lennoxensis Salmon
R. opeongoensis Wilson

**R, orleansensis Wilson
R. patula Wilson

**R. robusta Wilson

**R. subcamerata Wilson
R. ottawaensis Wilson

**R. salmoni Wilson

**R. sinuata Wilson
Rhynchotrema increbescens (Hall)
R. ottawaense (Billings) = Drepanorhyncha ottawaensis (Billings)
Schizocrania filosa (Hall)
Skenidioides billingsi Schuchert and Cooper
S. ? merope (Billings)

22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Sowerbyella punctostriata (Mather)

*S. sericea (Sowerby). (Identification doubtful.)
**Strophomena billingsi Winchell and Schuchert

S. filitexta Hall

S. f. obesa Wilson

S. magna Wilson

S. ? millionensis affinis Wilson

S. rotunda Wilson

S. venustula Wilson

Trematis terminalis (Emmons )

Trigrammaria trigonalis prima Wilson

Triplecia cuspidata (Hall) = Triplesia cuspidata (Hall)

T. extans (Emmons) = T. extans (Emmons)
**V ellamo trentonensis (Raymond)

Zygospira recurvirostris (Hall)

Correlation of Rockland formation and remarks on the listed brachiopods.—
The Rockland formation has hitherto been correlated with the upper part of the
Decorah of the Mississippi Valley, but the above list indicates that the Ottawa
Valley Rockland formation contains elements of the Prosser formation of the
Mississippi Valley as well. Prosser elements are: Vellamo, Platystrophia, On-
niella, and Parastrophina.

The discrepancies in the above list are interpreted as defects in the listing
rather than indicating that the Rockland formation correlates with the Decorah
and Prosser of the Mississippi Valley. If this were the case the Hull and Sher-
man Fall formations would need to be completely reevaluated. The work of Kay
has shown these to be consistently identified over wide areas. The writer has
therefore placed the Rockland in the position and correlation given it by Kay

(1937).

HEAD OF THE ST. LAWRENCE VALLEY IN NEW YORK AND ADJACENT CANADA

This area includes the Black River Valley of New York, the Watertown area
of New York, and the adjacent part of Ontario along the north side from Kings-
ton westward. The Ordovician about Coboconk described by Okulitch (1939)
is on the westward side of the belt. The Black River rocks of this area were
described by Young (1943) and the Early Trentonian by Kay (1937). The
area is a well-known one numbering several formations almost as old as the
science of geology in New York. From the bottom up the section is: Pamelia,
Lowville, Chaumont (including several members), Rockland (with two mem-
bers: Selby and Napanee).

Pamelia formation.—This formation has its greatest thickness in Jefferson
County, N. Y., where it is 150 feet thick. It consists of a lower division of about
70 feet composed of basal conglomerate and arkosic sandstones, dark-gray fos-
siliferous rock, sublithographic limestone interbedded with gray dolomitic lime-
stone. The upper division is about 80 feet thick, of light-gray or whitish earthy
limestone interbedded with gray magnesian and sublithographic limestone. In
both divisions the dolomitic and earthy limestones weather to a buff or yellow-
ish-brown hue, and are thus readily distinguished from the overlying Lowyville.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 23

The formation thins to the east and west of its area of greatest thickness. It
thins to disappearance in Oneida County, N. Y., to the east, and Okulitch reports
the Shadow Lake formation, equivalent of the Pamelia, as only 18 feet thick in
the vicinity of Coboconk, Ontario.

The upper member is more persistent than the lower one. The formation is
also marked by shallow-water phenomena such as ripple marks and mud cracks.
Fossils are rare in this formation. Cryptophragmus is present in the lower divi-
sion. Ancistrorhyncha sp.=A. costata Ulrich and Cooper and Zygospira recur-
virostris (Hall) are the only brachiopods reported by Young (1943, p. 234) in
his extensive studies of this formation.

The age and affinities of the Pamelia formation have been the subject of con-
siderable debate (Young, 1943, p. 151) but it is generally conceded now that
it has its strongest ties with the Lowville rather than with the Chazy group.
This is certainly the indication given by the few fossils that have been taken
from it. The two mentioned brachiopods place the Pamelia fairly high. Zygo-
spira in the Appalachians is not known until the time of Witten deposition, but
Ancistrorhyncha is slightly older. The Pamelia appears to be a part of the Low-
ville and probably varies in age from place to place.

Lowville formation.—This name has been widely used in the eastern United
States and Canada as a formation name, but such use should be discouraged
outside of New York, Ontario, and Quebec. Only in these latter regions can
the formation be shown to be a laterally continuous unit. Elsewhere the name
has use only in a facies sense for so-called dove limestones.

In its type region the formation is 34 feet thick but a short distance away it is
54 feet thick. It thins to the southeast to 6 to 10 feet in the Mohawk Valley.
To the west it is 40 feet thick at Kingston and 47 feet at Marmora, Hastings
County. Okulitch records the Gull River formation, equivalent of the Lowville
at Coboconk, as 45 feet. The formation is divisible throughout its extent into
a lower and upper part, the former generally thin bedded and the latter heavy
bedded. In Ontario the Lowville usually is shalier than in New York.

The lithologic types seen in the Lowville are dove-gray and dark sublitho-
graphic limestones usually in thick beds and often with calcite-filled worm bor-
ings and tangled nets of the coral Tetradium cellulosum. Dark semicrystalline
and argillaceous limestones are often interbedded with the sublithographic beds.
Granular beds and oolites also occur. The lower beds are often conglomeratic
and the formation rests disconformably on the Pamelia or on Canadian rocks
where the Pamelia has been overlapped. Mud-cracked and ripple-marked shales
indicate shallow-water deposition.

Fossils are fairly common in Lowville rocks but the preservation is often poor
and it is difficult to extract specimens from the sublithographic limestones. The
following brachiopods are reported:

*Rafinesquina minnesotensis = Opikina
*Rhynchotrema sp. cf. increbescens (Hall)
Strophomena sp.

Zygospira recurvirostris (Hall)

24. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Chaumont formation.—This name was proposed by Kay (1929a, p. 644)
for rocks occupying the interval between the Lowville and the Rockland in
Jefferson County, N. Y. The name was made to include three members in
ascending order: Leray, Glenburnie, and Watertown. The Leray member con-
sists of 13 feet of heavy-bedded, dark brownish-gray to black limestone con-
taining considerable chert. This member in the type region of the Chaumont
is separated from the Watertown by 2 feet of fossiliferous shale, the Glenburnie.
The Watertown limestone, or top member, comprises 13 feet of massive lime-
stone without chert except for the lower part. Outside the type area it is diffi-
cult to separate the Leray and Watertown.

The Chaumont formation thins to the south and east and is absent at Middle-
ville, N. Y., and in the Mohawk Valley. When the formation is followed to the
west it tends to become thinner bedded, browner, and with chert absent, irregu-
larly spread through it, or confined to the top. The formation is also less easy
to separate from the Lowville but the faunal content is persistent. The forma-
tion attains as much as 25 feet in thickness north of Peterborough, Ontario, but
thins again in the vicinity of Lake Simcoe.

Brachiopods are fairly common and varied in the Chaumont formation:
*Camerella volborthi Billings
Doleroides gibbosus (Billings)

D. pervetus (Conrad)
*Glyptorthis bellarugosa (Conrad)
*G. insculpta (Hall)

Hesperorthis tricenaria (Conrad) = H. concava Cooper
Hesperorthis sp.

Leptaena radialis Okulitch = Cyphomena ? radialis (Okulitch)
Pionodema sp. 1

Rafinesquina clara Okulitch = Opikina clara (Okulitch)

R. minnesotensis (N. H. Winchell) = Opikina minnesotensis (N. H. Winchell)
*Rhynchotrema sp. cf. increbescens (Hall)
*Strophomena sp. cf. delicatula Fenton

Strophomena sp.

“Valcourea deflecta (Conrad)”

Zygospira recurvirostris (Hall)

Rockland formation.—This term refers to beds overlying Chaumont and
underlying Hull limestone. The formation is typically developed in Ottawa Val-
ley but occurs also in western New York and Ontario. The formation is 64 feet
thick east of Dexter, N. Y., and is of similar thickness in Lennox and Addington
County, Ontario. Two members have been distinguished in New York and
Ontario: Selby member and Napanee member.

Selby member of Rockland formation—Kay (1937, p. 252) proposed this
name for dark-gray to black, medium- to fine-textured, petroliferous thin-bedded,
buff-weathering limestones characterized by the brachiopod Doleroides ottawanus
Wilson. The member is recognized in New York in Jefferson County where it
extends southeast to about East Martinsburg in the Black River Valley, in
Lewis County. At Lowville, N. Y., it is about 15 feet thick. It is exposed in

PART. I CHAZYAN AND RELATED BRACHIOPODS—COOPER 25

southern Lennox and Addington County, Ontario, but is overlapped to the west.
Brachiopods are:

*Dalmanella rogata (Sardeson) = Paucicrura rogata (Sardeson)

Doleroides ottawanus Wilson

D. pervetus (Conrad)
*Hesperorthis tricenaria (Conrad)

Rafinesquina alternata (Conrad)

Rhynchotrema sp.

*Sowerbyella curdsvillensis (Foerste)

Strophomena sp.

Napanee member of Rockland formation—This member was named by Kay
(1937, p. 255) after Napanee, Ontario. The member is well exposed in western
New York and central Ontario. At the type section it is 34 feet of gray-blue,
medium-textured, heavy-ledged limestone with shaly partings, particularly in
the lower part. In New York it occurs at all areas having the Selby member,
but is absent from the Western Canada Creek and Mohawk Valleys except for
local occurrences at Inghams Mills and Newport Quarry in Herkimer County.
Westward from Napanee it extends to Peterborough County, Ontario. Still
farther west it is thought to be represented by the Coboconk limestone. Brachio-
pods recorded from the Napanee member are:

Camerella obesa Cooper

C. volboriit Billings

Dalmanella rogata (Sardeson) = Paucicrura rogata (Sardeson)
Hesperorthis tricenaria (Conrad)

Parastrophina hemiplicata (Hall)

Protozyga exigua (Hall)

Rafinesquina alternata (Conrad)

“R.” inquassa (Sardeson) = Opikina inquassa (Sardeson)
R. lennoxensis Salmon

R. olliformis Salmon

Sowerbyella punctostriata (Mather)
*Strophomena filitexta (Hall)

Trigrammaria wilsonae Cooper

Triplesia cuspidata (Hall)

SECTION AT COBOCONK, CENTRAL ONTARIO

In central Ontario Black River—Rockland rocks make a narrow belt extending
east-west from Kingston to Victoria Harbour on Georgian Bay. Sections studied
by Okulitch (1939) are located on Highway 35 between Coboconk and Norland.
Four formations in ascending order are recognized: Shadow Lake, Gull River,
Moore Hill, and Coboconk.

Shadow Lake formation.—This basal formation, 18 feet thick, consists of
unfossiliferous purple and green shales and magnesian limestones or dolomites.
The position of the formation resting on the pre-Cambrian and the lithologic
character are suggestive of the Pamelia formation of New York.

Gull River formation.—Compact, light-gray, aphanitic limestone, 45 feet

26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

thick, with some magnesian and shaly limestone at the base. Fossils are rare
but the following brachiopods are recorded:

Rafinesquina cf. alternata (Emmons) = R. cf. R. trentonensis (Conrad)

R. clara Okulitch = Opikina clara (Okulitch)

R. minnesotensis Winchell = O. minnesotensis (N. H. Winchell)

*Strophomena incurvata (Shepard)

Strophomena sp.

Zygospira recurvirostris (Hall)

Presence of Crytophragmus and some other fossils suggests lower Lowville.
Moore Hill formation.—Consists of about 20 feet of limestone containing
“birdseyes” and in the lower part thin aphanitic beds and thin greenish layers.
Tetradium celluloswm, Lambeophyllum, and Stromatocerium are common. The
brachiopods recorded are:
*Rafinesquina cf. alternata (Emmons) = R. cf. R. trentonensis (Conrad)
R. clara Okulitch = Optkina clara (Okulitch)
*R. minnesotensis (N. H. Winchell) = Opikina minnesotensis (N. H. Winchell)
Rafinesquina n. sp.
*Strophomena filitexta Hall
Zygospira recurvirostris (Hall)

Coboconk formation.—This formation consists of 20 feet of moderately
heavy-bedded, aphanitic to fine-grained limestone, gray-brown to gray and
weathering brown. The uppermost bed is of fine- to medium-grained limestone
containing a fauna with some different species from those below. Cryptophrag-
mus is present in the lower beds but Receptaculites occidentalis, Calapoecia cana-
densis, Hesperothis tricenaria, and Maclurites logani occur in the top layer.
Brachiopods are:

Leptaena cf. radialis Okulitch = Cyphomena cf. C. radialis (Okulitch)
Rafinesquina alternata (Conrad) = Rafinesquina trentonensis (Conrad)
R. clara Okulitch = Opikina clara (Okulitch)

R. minnesotensis (N. H. Winchell) = 0. minnesotensis (N. H. Winchell)
Strophomena cf. corrugata Okulitch

*S. filitexta Hall. (Identification doubtful.)
Zygospira recurvirostris (Hall)

According to Okulitch the lower beds have affinities with Chaumont but Kay
(1937, p. 250) argues that the Coboconk is of Rockland age. Okulitch believes
that the only Rockland elements occur in the uppermost bed as listed above. He
believes further that the whole formation is correlative to Chaumont age be-
cause the characteristic Rockland elements are missing. The only Rockland he
will concede is the uppermost bed. On the chart the entire Coboconk is correlated
with the Rockland.

MANITOULIN ISLAND REGION

Foerste (1912a, pp. 38-41) described the stratigraphy of Cloche Island and
others of the Manitoulin Group and assigned ages to several of the beds. Kay
(1937, pp. 257-259) discusses the same sequence but assigns the ages differently
from Foerste. Two of the three formations were named by Foerste in ascending
order: Lowville, Swift Current, and Cloche Island.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 27

Lowville formation.—The lowest Ordovician rocks of the region are ex-
posed on the west side of Cloche Peninsula and consist of at least 60 feet of
reddish clay shale that produced a few fossils. The only brachiopod recorded is
Lingulella clochensis (Foerste).

Swift Current formation.—This consists of a possible 50 feet of section ac-
cording to Foerste’s estimate. The lower beds are reddish limestone or dolomite
with fragmental material at the base in which are mixed a number of Ordovician
species. The higher beds are of fine-grained, white, “birdseye’’ limestone poor in
fossils. Except for the basal beds, few fossils occur except at the base of the
white “birdseye” limestone where the same fauna as that at the base is found.
Foerste lists the following brachiopods:

Pionodema sp.
Rhynchotrema ainsliet (N. H. Winchell) = Rostricellula rotundata Cooper

Foerste suggests that the Swift Current formation resembles the Tyrone of
Kentucky but Kay refers it to the Chaumont division of the Black River.
Cloche Island formation.—This formation is composed of 55 feet of light-

gray, heavy-bedded limestone with shaly beds in the lower part. It occupies most
of the southern part of Cloche Island and may extend to Delta County, Mich.
Brachiopods listed by Kay and others are:

Camerella panderi Billings =Idiospira panderi (Billings)

C. volborthi Billings

Dalmanella rogata (Sardeson) = Paucicrura rogata (Sardeson)

Dinorthis sweeneyi (N. H. Winchell)

Doleroides pervetus (Conrad)

Glyptorthis bellarugosa (Conrad)

Hallina sp.

Hesperorthis tricenaria (Conrad)

Rafinesquina alternata (Conrad) = Rafinesquina trentonensis (Conrad)

“R.” inquassa (Sardeson) = Opikina inquassa (Sardeson)

Rhynchotrema increbescens (Hall)

Rostricellula rotundata Cooper

Sowerbyella punctostriata (Mather)

*Strophomena sp. S. emaciata Winchell and Schuchert

*S. filitexta (Hall)

Kay (1937, p. 257) correlates this formation with the Rockland of Ottawa
and with the Guttenberg of the upper Mississippi Valley section. The fossils
recorded above, if correctly identified, indicate that the Cloche Island formation
may embrace a somewhat higher part of the Trenton as well. The Cloche Island
on the chart is made equivalent to the Rockland of the Ottawa Valley, otherwise
difficulties arise with the higher formations. All these faunas need revision.

3. CHAMPLAIN, MOHAWK, AND HUDSON VALLEYS
CHAMPLAIN VALLEY (WEST SIDE)
In and about the village of Chazy, Clinton County, N. Y., on the west side

of Lake Champlain, a considerable body of fossiliferous rocks, nearly goo feet
on Valcour Island, has long been known as the Chazy limestone (here called

28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Chazy group). The sequence is best displayed on Valcour Island, N. Y., but
good sections are also known at Crown Point, N. Y., and on Isle la Motte, Vt.
The sequence was early separated into three divisions by Brainerd and Seely
(1896) who designated them A, B, and C. Later, Cushing (1905) proposed to
substitute the name Day Point for division A, Crown Point for division B, and
Valcour for Division C. Raymond and others have expressed dissatisfaction
with these names because the terms applied do not accord with the sections at
the various places. For example, the section at Day Point belongs to the Crown
Point formation. This is really not an issue because the Cushing names were
made as substitutes for the Brainerd and Seely divisions and the reference sec-
tions must be those given by Brainerd and Seely for their divisions rather than
the locations from which Cushing took his names.

Raymond (1905) made a detailed study of the fauna of the Chazy rocks on
the west side of Lake Champlain and further divided the beds into faunal zones.

Day Point formation.—This formation consists of gray sandstone inter-
bedded with layers of slate or occasional limestone layers near the base. These
beds are succeeded by nodular limestone that alternates with tough slate. The
next division is composed of limestone often packed with Orthambonites ?
exfoliata (Raymond). The uppermost limestone is in beds 8 to 20 inches thick
and has many beds of echinoderm fragments. The whole sequence is 338 feet
thick.

Brachiopods recorded from the Day Point formation are:
Camerella ? costata Billings
C. longirostris Billings = Onychoplecia longirostris (Billings)
Lingulella brainerdi (Raymond)
Orthis acutiplicata Raymond = Orthambonites acutiplicatus (Raymond)
O. exfoliata Raymond = Orthambonites ? exfoliatus (Raymond)
Palacoglossa belli (Billings)
Rafinesquina incrassata = Dactylogonia incrassata (Hall)
Schizambon ? duplicimuratus Hudson=S. ? duplicimuratwm Hudson

Correlation of Day Point formation.—The Day Point for the most part con-
stitutes Raymond’s Hebertella exfoliata zone or division 1. This zone contains
brachiopods and other fossils that are confined to it. At present no satisfactory
correlation of this formation can be stated. The fauna seems not to have any
connections with that of the Table Head or its equivalents and it is not assign-
able to the Whiterock stage. The listed species are mostly related to higher
Crown Point forms.

Crown Point formation.—This formation consists of 200 to 400 feet, mostly
of dark fine-grained, heavy-bedded limestone with occasional beds of light-gray
coarsely crystalline limestone. Brachiopods are common:

Camarella longirostris Billings = Onychoplecia gracilis (Raymond)

Camerella varians Billings

Camarotoechia pristina Raymond = Rostricellula pristina (Raymond)
Clitambonites multicostatus Hudson = Atelelasma ? multicostatum (Hudson)

Hebertella bellarugosa (Conrad) = Glyptorthis sulcata Cooper
H, vulgaris Raymond = Mimella vulgaris (Raymond)

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 29

Leptaena incrassata Hall = Dactylogonia incrassata (Hall)

Leptellina primaria Cooper

Lingulella columba Raymond

Mimella nucleoidea Cooper

M. ulrichi Cooper

Multicostella platys (Billings)

Orthidium ? lamellosum Raymond = Ptychoplewrella lamellosa (Raymond)
Orthis costalis Hall = Hesperorthis ? costalis (Hall)

O. ? porcia Billings = Ptychopleurella porcia (Billings)

Petrocrania prona (Raymond)

Rafinesquina champlainensis Raymond = Macrocoelia champlainensis (Raymond)
R. distans Raymond = Glyptomena ? distans (Raymond)

R. fasciata Hall = Dactylogonia incrassata (Hall)

Rhynchonella ? acutirostris Hall = Sphenotreta acutirostris (Hall)
Schizambon duplicimuratum Hudson

Strophomena prisca Raymond = Glyptomena ? prisca (Raymond)
Triplecia gracilis Raymond = Onychoplecia gracilis (Raymond)

Valcourea strophomenoides (Raymond)

Zygospira acutirostris (Hall) = Sphenotreta acutirostris (Hal!)

Correlation of Crown Point formation—This formation is correlated with
parts of the Mingan formation, the McLish formation, and the Lenoir formation.
All the named formations also have elements of the Valcour fauna in them and
all are correlated with the Crown Point—Valcour interval.

Valcour formation.—This is division 3 of Raymond, or the Camarotoechia
(=Rostricellula) plena zone. The formation contains massive dove-colored
limestone at the base followed by impure limestone abounding in Rostricellula
plena. The formation is capped by sandy magnesian limestone passing into sand-
stone. It is 172 feet thick. The following brachiopods have been reported :
Camarotoechia major Raymond = Rostricellula major (Raymond)

C. plena (Hall) = R. plena (Hall)

Dactylogonia sp.

Glossina belli Billings = Palaeoglossa belli (Billings)
Hebertella costalis (Hall) = Hesperorthis ? costalis (Hall)
Mimella transversa Cooper

M. valcourensis Cooper

Orthis ignicula Raymond = Hesperorthis ignicula (Raymond)
Rostricellula plena altilis (Hall)

R. plena plicifera (Hall)

Correlation of Valcour formation —Except for the continuation of this forma-
tion in Canada, no other Chazy beds are quite like it. In the Appalachians the
Lenoir formation contains elements of the Valcour as well as of the Crown Point.
This is true also of the Mingan and McLish faunas. Furthermore, the Valcour
contains species and genera that are related to Crown Point species or holdovers
from that formation. It seems best, therefore, to include the Valcour formation
with the Crown Point formation as a unit in correlation.

Lowville formation.—This formation is represented by only 5 feet or a
little more of heavy-bedded (6 to 12 inches) dove-colored limestone. The “birds-
eyes” characteristic of the formation occur throughout. The only brachiopod
reported is Zygospira recurvirostris (Hall).

30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Chaumont formation.—In the Crown Point section (Raymond, 1902, p. 21),
Kay (1937, p. 259) states that beds 19 to 23 should be assigned to the Chaumont.
The thickness is about 26 feet. Raymond records the following brachiopods.

Dalmanella subaequata pervetus = Doleroides pervetus (Conrad)
Hesperorthis ? costalis (Hall) ?

*Plectorthis plicatella (Hall)

*Rafinesquina alternata (Conrad)

*Rhynchotrema inaequivalve (Castelnau)

*Strophomena incurvata (Shepard)

Zygospira recurvirostris (Hall)

Some of the above brachiopods are undoubtedly incorrectly identified, but it
is not possible to make revision without studying a collection from this forma-
tion. Rafinesquina is generally absent from the Chaumont. If the fossils are
correctly identified the limestone might be assigned to the overlying Amsterdam
formation.

Amsterdam formation.—According to Kay (1937, p. 259) beds 24 and 25
of Raymond’s Crown Point section plus the lower 4 feet of bed 26, about 17 feet
in all, belong to the Amsterdam formation of Cushing which is better displayed
in the lower Mohawk Valley. The following brachiopods are reported by
Raymond:

*Dalmanella testudinaria = Paucicrura ? sp. ?

*Dinorthis pectinella (Emmons)

Plectorthis plicatella (Hall)

Rafinesquina alternata (Conrad) = Rafinesquina trentonensis (Conrad)

*Strophomena incurvata (Shepard)
Zygospira recurvirostris (Hall)

If the brachiopods recorded above are correctly identified, assignment of this
manifestation of the Amsterdam formation to a position equivalent to high
Decorah (Ion) would be necessary, but this is not in accord with faunas of
overlying formations.

Isle la Motte formation.—Kay (1937, pp. 259, 260) assigns the remainder
of bed 26 and beds 27 and 28, about 16 to 20 feet of limestone, to the Isle la Motte
formation. At the type section this is 10 feet of black, gray-weathering, heavy-
bedded limestone. This formation extends to the south to the vicinity of Glens
Falls, N. Y. Brachiopods listed by Raymond are:

Dalmanella testudinaria = Probably Paucicrura

Dinorthis pectinella (Emmons)

Glossina trentonensis (Conrad)

Rafinesquina alternata (Conrad) = Rafinesquina trentonensis (Conrad)
Strophomena incurvata (Shepard)

Triplecia extans (Emmons) = Triplesia cuspidata (Hall)

Correlation of Isle la Motte formation.—Kay (1937, p. 261) correlates the
Isle la Motte formation with the Rockland of Ontario because of Triplesia and
other fossils such as Maclurites logani and Colwmnaria hall. If the recognition
of these formations in the Crown Point section is correct the position of the
Amsterdam formation is made clear between the Chaumont and Isle la Motte.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 31

It also means that listed fossils from the lower formation are either long ranged
or misidentified. The Isle la Motte formation is overlain by the Larrabee forma-
tion which is correlated with the Hull formation of Ontario and western New
York because of abundance of Parastrophina.

PHILLIPSBURG THRUST SLICE

In southern Quebec, just north of the Vermont border and on the east side
of Lake Champlain, a long sequence of Ordovician rocks is revealed in the
Phillipsburg slice which is thrust over the Iberville shale. Most of this slice
is composed of Lower Ordovician formations but these are overlain by the
Mystic conglomerate or breccia (Clark, 1934, pp. 6, 7). This formation is com-
posed of limestone boulders of varying size, often quite large. These boulders
are of several ages but the ones of immediate interest here are the youngest ones.
These are of gray, granular limestone abounding in fossils related to those of
the Table Head series of Newfoundland. This assemblage is of considerable
interest because the fauna is known nowhere in the vicinity in an undisturbed
sequence. Affinities with the highest Pogonip of Nevada are also apparent.
Brachiopods from the youngest boulders are:

Acrotreta magna Cooper Palaeoglossa mysticensis Cooper

Bimuria ? matutina Cooper Paucicostella canadensis Cooper
Camerella breviplicata Billings Pleurorthis convexa Cooper

C. polita Billings P. corinna (Billings)

Hesperonomiella quebecensis Cooper P. costellata Cooper

Idiostrophia costata Ulrich and Cooper P. fascicostellata Cooper

I. perfecta Ulrich and Cooper Ptychoglyptus sp. 1

Idiostrophia sp. 1 Rhysostrophia elliptica Ulrich and Cooper
Neostrophia subcostata Ulrich and Cooper R. transversa Ulrich and Cooper

CHAMPLAIN VALLEY (EAST SIDE)

In west-central Vermont Cady (1945, pp. 548-554) described a series of Chazy
rocks which are mostly poorly fossiliferous and of uncertain classification. The
sequence from the top down is Middlebury limestone, Beldens formation, and
Crown Point limestone. The last limestone is about 60 feet thick at Orwell, Vt.,
but thickens to 150 feet to the north. It is mostly gray, compact, massive lime-
stone containing Maclurites “magnus” (LeSueur). The Beldens formation is
buff-weathering dolomite interbedded with white marble. The formation con-
tains the Weybridge member consisting of limestone with thin sandy streaks.
The formation ranges up to 700 feet in thickness. Fossils are very rare. The
Middlebury limestone, which attains a thickness of about 600 feet, is dark, blue-
gray, partially dolomitic limestone with buff streaks.

In northwestern Vermont Kay (1945, p. 1171; 1947, p. 601) described a
sequence consisting of the Beldens white, dense limestone 500 feet thick, fol-
lowed by the Carman quartzite 60 to 125 feet thick. The latter is succeeded by
the Youngman formation composed of argillaceous limestone grading upward
into dark slate with interbedded limestone. The Youngman formation contains
the brachiopod Christiania and the trilobite Lonchodomas halli (Billings).

32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Kay (1947, p. 601) suggested substitution of the name Burchards for the
“Crown Point” formation “east of the Champlain thrust” because it is “struc-
turally separated from the Crown Point limestone of the type locality and other
outcrops in New York and is succeeded by the Beldens formation rather than
by the Valcour limestone.”

Correlation of formations on the east side of the Champlain Valley.—In a
recent table of correlations Kay (1948, p. 1402) indicates equivalence of the
Carman quartzite with the sandstone at the base of the Day Point formation in
New York. The Youngman formation then becomes the equivalent of the Crown
Point and Valcour limestones of New York. The Beldens and Burchards are
not equivalent to any known formation under this arrangement. Inasmuch as
these correlations are based on the lithology of two sandstones and not on fos-
sils, they cannot be regarded as reliable. Based on what fossil evidence is avail-
able another arrangement is possible which is more in harmony with the known
fossils.

Inasmuch as the Burchards was originally called Crown Point and does con-
tain Maclurites according to Cady (1945, pp. 548-549) it is reasonable to cor-
relate the Burchards with the Crown Point limestone. This places the Beldens
as a possible equivalent of a sandstone at the top of the Valcour formation al-
though no other evidence than position is now known. The Youngman forma-
tion with Christiania, by this arrangement would be thrown above the Chazy.
This is in complete harmony with a similar situation in the Southern Appa-
lachians where the Christiania beds of the Arline formation, probable equiva-
lent of the Youngman, occur above Lenoir limestone with fossils that indicate
correlation with the Crown Point-Valcour sequence.

LOWER MOHAWK AND UPPER HUDSON VALLEYS

Rocks deposited in the times embraced within this monograph are not well
developed in this part of New York. The Lowville appears as remnants, about
27 feet thick at Inghams Mills and 6 feet at Amsterdam, according to Kay (1937,
p. 254). It is not known at Glens Falls in the upper Hudson Valley but is
present in the Champlain Valley as noted above. The Chaumont formation was
not identified by Kay in the Lower Mohawk Valley but does appear in the
Champlain Valley.

Amsterdam formation (Mohawk limestone of Conrad).—This formation
is 11 feet thick in its type region but increases to 23 feet at Glens Falls. In the
Saratoga Springs region Cushing and Ruedemann (1914, pp. 45-47) indicate
an underground thickness of 40 to 60 feet. In the Saratoga region the limestone
is somewhat thin bedded, crystalline, and fossiliferous. Kay (1937, p. 259) re-
ports it as gray-black and heavy ledged in many sections in the Mohawk Valley.
Few brachiopods have been listed from the formation:

Dalmanella rogata (Sardeson) = Paucicrura rogata (Sardeson)
Dinorthis pectinella (Emmons)

Rhynchotrema sp.

Strophomena trentonensis Winchell and Schuchert

Zygospira sp.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 33

Correlation of Amsterdam formation—Kay (1937, p. 259) shows that the
Amsterdam limestone in the Crown Point section overlies the Chaumont forma-
tion (although the listed fossils are typical) and underlies the Isle la Motte lime-
stone which is classified as equivalent to the upper Rockland. The Amsterdam
is thus probably to be correlated with the lower part of the Rockland formation.

Isle la Motte formation.—This formation was named from the Champlain
Valley and consists of black, gray-weathering limestone, medium textured and
heavy bedded. It is about 10 or 11 feet thick at the type section. It occurs
southward at many sections from Isle la Motte to Glens Falls in the upper Hud-
son Valley where it retains its heavy-bedded character but is considerably thicker,
about 16 feet. Strophomena and Zygospira are listed as occurring in it at Glens
Falls. The Isle la Motte limestone contains fossils that are associated with
Triplesia cuspidata (Hall) elsewhere and therefore correlated by Kay (1937,
p. 261) with the upper Rockland of the Ottawa Valley.

The Glens Falls limestone is overlain by the Larrabee formation which is re-
garded as equivalent to the Hull formation.

HUDSON VALLEY REGION (ALBANY TO POUGHKEEPSIE )

Rocks deposited in early Middle Ordovician time are not developed in the
form of-limestones in the region around Albany but the shelly facies is developed
to a limited extent in the neighborhood of Poughkeepsie, N. Y. In Hudson
Valley between Albany and Poughkeepsie the dark shales and slates of the
Normanskill formation are developed. These abound in graptolites, but few
brachiopods have been taken from them.

Normanskill formation.—This formation has been divided into two mem-
bers: The lower one the Mount Merino chert and shale and the upper one
called the Austin Glen grit and shale. The formation is estimated to be about
2,000 feet thick, but it has proved impossible to make accurate measurements.
The bulk of the formation consists of shale, but grit, sandstone, chert, arkose,
and conglomerate, ranking in the order named, are present.

Mount Merino member.—This member is mainly located on the east side of
the Hudson and is characterized by considerable chert which, owing to its com-
petent character, forms the backbone of some of the prominent hills in the Hud-
son Valley. The chert often contains numerous radiolaria (Ruedemann and
Wilson, 1936). Black shales, especially those from the type section at Mount
Merino, a quarry on the north side of the mountain, have produced more than
69 species of graptolites which make up the Nemagraptus zone of the Norman-
skill. These correlate with the lower part of the Athens formation of Tennessee,
the Blockhouse formation of East Tennessee, the Columbiana formation of Ala-
bama, the Paperville formation of Virginia, and other formations that contain
this graptolite. The following brachiopods occur:

Leptobolus walcotti Ruedemann

Paterula amii Schuchert
Schizotreta papilliformis Ruedemann

34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Austin Glen member.—This member is composed of thick and thin beds of
grit and shale, but the former predominates. The member is chiefly confined to
the west side of the river. Fossils are rare in the Austin Glen member, but a
few graptolites, eurypterids, and other fossils have been taken. Brachiopods are
not reported. Corynoides and Diplograptus are two important graptolites of
this member.

Overlying the Normanskill formation is an interesting conglomerate contain-
ing pebbles of several formations, and known as the Rysedorf conglomerate.

Rysedorf conglomerate.—This conglomerate is of varying thickness, from
a few feet to 50 feet. Ruedemann (1930, p. 104) states “The Rysedorf con-
glomerate has a wide distribution within the Normanskill shale belt in the capi-
tal district; but it also extends into the Schuylerville quadrangle, where the
writer has described it from the base of Bald Mountain (’14, p. 80) ; and it is
found at Schodack Landing and may be identical with the Burden conglomerate
described by Grabau from Becraft mountain near Hudson.”

The pebbles of the Rysedorf conglomerate are of several kinds: gray lime-
stone of early Cambrian age, black crystalline limestone with Bolboporites, said
to be Chazy limestone (not necessarily so because Bolboporites is common in
the lower part of the Edinburg formation in Virginia), Lowville limestone with
Tetradium cellulosum, and black compact limestone with a prolific fauna related
to the Chambersburg of Pennsylvania and the Edinburg formation of Virginia.
This fauna is of considerable interest because it is impossible to derive it from
any known source near Albany. The brachiopods of this suite of black limestone
pebbles are:

Christiania trentonensis Ruedemann

Crama trentonensis Hall = Petrocrania trentonensis (Hall)
*Dalmanella testudinaria (Dalman) = Paucicrura ?

Leptaena rhomboidalis Wilckens = L. ordovicica Cooper

Orthis tricenaria Hall (sic) = Hesperorthis sp.
*Platystrophia biforata (Schlotheim)
*Plectambonites sericeus (Sowerby)

P. pisum Ruedemann = Bilobia pisum (Ruedemann)

Rafinesquina alternata (Emmons) = Macrocoelia ruedemanni (Salmon)
Siphonotreta minnesotensis Hall and Clarke

Ruedemann correlates this fauna with that of the Chambersburg limestone,
but the part of that formation is not stated. Christiania occurs throughout the
Edinburg formation which is a southwestward extension of part of the Cham-
bersburg formation, but some of the other fossils occur more commonly in the
Oranda formation just above the Edinburg such as Leptaena, Rafinesquina, and
Hesperorthis. The possibility of these pebbles having been derived from the
Youngman formation of Vermont should not be overlooked. This formation also
contains Christiania, but the rest of the fauna is not known.

The presence of Platystrophia in these pebbles of the Rysedorf conglomerate
is probably an error of identification. This genus has not yet been seen in the
Chambersburg or Edinburg formations. It is suggested that Oxoplecia has been
mistaken for Platystrophia. The Rysedorf conglomerate also reminds one

PART I - CHAZYAN AND RELATED BRACHIOPODS—COOPER 35

strongly of the Quebec City limestone which has Edinburg and possibly Young-
man elements in it.

Another group of pebbles are composed of compact reddish-gray limestone
and contain the following brachiopods:
Dalmanella testudinaria (Dalman)
Protozyga exigua Hall = Cyclospira ? longa Cooper

Rafinesquina alternata (Conrad)
Triplecia nucleus Hall

These are undoubtedly of Trenton age problably younger than the preceding.
A final group of pebbles are of gray crystalline limestone and are the com-

monest in the conglomerate. They abound in Rafinesquina and Sowerbyella.

These contain also:

Dalmanella testudinaria (Dalman)

Dinorthis pectinella (Emmons)

Leptaena rhomboidalis (Wilckens) = L. ordovicica Cooper

Orthis tricenaria Conrad = Hesperorthis tricenaria (Conrad)

Parastrophia hemiplicata Hall = Parastrophina hemiplicata (Hall)

Plectambonites ruedemanni Raymond

P. piswm Ruedemann = Bilobia piswum (Ruedemann)

Plectorthis plicatella Hall

Protozyga exigua (Hall)

Rafinesquina alternata (Conrad)

R. deltoidea (Conrad)

Triplecia nucleus Hall

Zygospira recurvirostris (Hall)

Ruedemann dates this fauna as early Trenton. The presence of Parastrophina
suggests Hull, and this is thus the youngest fauna in the conglomerate.

VICINITY OF POUGHKEEPSIE, N, Y.

Ordovician limestone appears in two northeast-southwest belts in the Pough-
keepsie Quadrangle ; the westernmost one is the Wappinger belt and the eastern-
most one is the Fishkill belt. Fair fossils have been produced from the Wap-
pinger belt in the vicinity of Pleasant Valley and Rochdale, Poughkeepsie (15’)
Quadrangle. The Wappinger Creek belt is the only one mentioned here because
fossils from the two localities mentioned above are recorded. At the railroad cut
at Pleasant Valley Tetradium cellulosum is recorded from dove limestone
(Knopf, 1927, p. 439). These are dated as Lowville, but it is conceivable that
they actually belong to the Trenton. The dove beds are overlain by 65 feet of
gray shale according to Knopf. The shales are followed by fine-grained, dark-
gray, bluish-weathering limestone containing fossils. Another locality for fossils
is on Wappinger Creek at Rochdale about 24 miles southwest of Pleasant Valley.
Brachiopods recorded from these two places are:

Dalmanella testudinaria = Paucicrura ?
Idiospira ? warthini Cooper

Lingula sp.

Nicolella angulata Cooper

36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Orthis pectinella = Dinorthis pectinella (Emmons)

O. tricenaria = Hesperorthis tricenaria (Conrad)
*Plectambonittes sericea = Sowerbyella sp.

Rafinesquina alternata = Rafinesquina trentonensis (Conrad)

These fossils suggest correlation with some part of the Rockland formation.

On the west bank of the Hudson (Gordon, r1gr1, p. 83) near Highland, dur-
ing construction of the railroad, graptolites were found in the shales that cover
a large portion of the west side of the Hudson in the Poughkeepsie Quadrangle.
These graptolites contain Nemagraptus and belong to the lower Normanskill
assemblage.

VICINITY OF NORTH CAMBRIDGE, N. Y.

A collection from three-quarters to a mile north of North Cambridge, N. Y.,
is of special interest. The rock is a coarsely granular, dark-gray limestone con-
taining a few brachiopods, Pleurothis ? sp., Bimuria ? sp., Onychoplecia,
Sphenotreta, and Ptychoglyptus sp. The specimens were taken from an area
mapped as the Georgia slate. The collection has been variously identified from
Ordovician to Silurian, the latter an obvious error.

The Pleurorthis is a questionable reference for some of the specimens because
they are plicate with the plicae overlain by costellae. No other orthid quite like
it is known to the writer. The Bimuria ? is similar to the small Bimurias from
the Pratt Ferry and Rich Valley formations and resembles B. ? matutina Cooper.
The Onychoplecia is a large one and is most like O. gracilis (Raymond) from
the Chazy group. The Ptychoglyptus is similar to P. ? kindlei. This compari-
son at once suggests Table Head or Mystic conglomerate as the probable rela-
tionship of these brachiopods. Doubt may be cast on this suggestion, however,
because Sphenotreta, a Marmor and Porterfield genus, has not yet been taken
in the Quebec or Newfoundland formations. It is possible, too, that these fossils
actually belong to a part of the Chazy group hitherto undiscovered. Possibly
they are related to the Youngman formation of Vermont which might be expected
to have these genera.

Nothing is now known of the field relationships of the rocks from which this
collection was taken. Possibly they came from boulders and are related to the
Mystic and the Table Head, but more probably they belong in some part of the
Chazy group or the early Porterfield stage Youngman formation.

4. THE APPALACHIANS (PENNSYLVANIA TO ALABAMA)

Many parts of the Appalachian Valley have been mapped in detail, and excel-
lent maps have been published showing the extent of the formations in Alabama,
Georgia, Tennessee, and Virginia. Yet with all this mapping and stratigraphic
work very little has been done with the faunas. A few fossils were published,
mostly without description, in reports on the geology of Alabama and Virginia,
but similar reports on Tennessee are not provided with any helpful material on
fossils. In fact only one paper on the brachiopods of the middle Ordovician of

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER a7

the Appalachians has ever appeared (Willard and Raymond, 1928). The prac-
tice has been general of identifying Appalachian species with described forms
from New York and Canada. These names have been applied without regard
to facies, which has been, until recently, disregarded in the Appalachians. The
vast stretch of elongated belts in the Valley thus afford almost virgin ground for
the paleontologist. This monograph is testimony to this long neglect. The stra-
tigraphy of the valley was not so long neglected, but it has been confused and

misunderstood.

IND. 1

CENTRAL P

; *KENTLAND A.
(UNION FURNACE)

»STRASBURG

/ “PENN LAIRD

\ -COLLIERSTOWN
BRIDGE pe *DUNKARD GHURCH
UZ *CATAWBA VALLEY
i “TA

ee dled ZEWELL

STORE_/ RYE ge es QUARRY
HAGAN NY VE “MARI
AGAIN, OVE srunpeZ TT

Nee mes
ee na ae cme.

TENN. LONE MINN “EIDSON
ROSE HILL**. *ST CLAIR aagrs MTN,
ANDERSONVILLE | —
CENTRAL *FLEANOR Wir os HOGSKIN
VALLEY
Gabe sLENOIR CITY J <

SEQUATCHIE Y
VALLEY * Sa pary FRIENDSVILLE

HIWASSEE RIVER. — FRONT

‘
"| ‘GHICKAMAUGA
i \ CREEK .
‘ —

H i oN SS

! 1

| *ATTALLAL
1

eGATE CITY
« CAHABA
VALLEY

*PRATT
FERRY

:
¥
\

; 25 50 75 100 wnes
i
i

Fic. 1.—Map showing location of sections in the Appalachians.

For years the Appalachian stratigraphy has been explained on the theory that
the Ordovician saw this area occupied by elongated seas separated by barriers.
This view has now been displaced by the idea that the sediments of the Appa-
lachian Valley were laid down in a normal geosyncline, and the long belts of
varying types of sediment are best explained as facies developments. In this con-
nection B. N. Cooper and I have prepared a detailed discussion of Appalachian
stratigraphy based on facies, which is a collateral work to this monograph on
the brachiopods and B. N. Cooper’s study of Appalachian trilobites.

38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

In the following portrayal of Appalachian stratigraphy I have arranged the
formations alphabetically. To discuss them on a regional or structural basis
would involve too much repetition. Consequently, formations proposed prior to
1936 are given with a list of brachiopod species and notes on correlation. Forma-
tions proposed after 1936, of which there are many, are described in more detail
and the brachiopods listed.

FACIES IN THE APPALACHIANS

The idea of facies is as old as geology, but the application of the idea to the
Appalachians is essentially new. Several of the pioneers in Appalachian geology
knew and expressed ideas on shifts of lithologies from one part of the Appa-
lachians to others. Keith, in particular, mentioned the passage of shales to lime-
stones in certain instances, but at the turn of the century Appalachian stratig-
raphy was explained by elongate seas and barriers. Lately this idea has been
challenged, and the classical theory of interlocking facies to explain Appa-
lachian sedimentation is now the vogue. It is possible to divide the facies into
the three basic rock types: Sandstones, shales, and limestones.

Sandstones——Among the sandstones several facies types can be recognized:
(1) The conglomerates often seen at the base of many of the formations but also
in great masses such as that at Fincastle, Va. Generally these make up a minor
portion of any section. Usually a basal conglomerate exists above the great un-
conformity on the Knox dolomite. (2) Coarse, clean quartz sands are not of
common occurrence but are prominent in the Bays formation in Bays Mountain.
(3) Shaly sandstones and mudstones are prominent, particularly in the upper
part of the section. As exhibited by the Moccasin formation these may be red,
green, or yellow and often mud cracked. The Bays and Moccasin formations
are the great examples of the red-bed facies, but the same types are occasionally
seen in the lower part of the section where they occur in the Surgener, Long
Savannah, Attalla, or Blackford formations, but seldom compose the whole mass.
Dirty sands, often ferruginous and occasionally with hematitic oolite, are ex-
hibited by the Tellico and Red Knobs formations.

Shales——The shales form rocks texturally intermediate between some of the
limestones and the sandstones and usually contain combinations of the two op-
posite types. (1) A prominent shaly type is the shaly sandstone or sandy shale
which covers hundreds of square miles as the Sevier formation. This is gen-
erally somewhat calcareous, and the fresh rock is a light blue. When leached
and weathered, however, it is generally a dirty yellow. Fossils are rare in the
Sevier, which generally is located in the easternmost belt of outcrop which is
partly overridden by the Great Smoky Mountain mass. (2) Black shales are
not prominent in the Appalachians except in a few areas such as that surround-
ing the city of Bristol in Virginia-Tennessee and in the Catawba Valley. The
black shales generally contain graptolites in more or less abundance. The grapto-
lite shales in the Appalachians, rather than being indicators of deep water, ap-
pear to be close shore deposits found in eastern belts or eastern belts that have
been shoved to the west. The graptolite-bearing rocks of the easternmost belt of

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 39

East Tennessee interfingers with platy sandstones which themselves often con-
tain fine graptolites. (3) Calcareous shales, often yellow-weathering, characterize
the Hogskin member of the Lincolnshire formation and most of the Benbolt
formation. These shales are reminiscent of the Sevier but do not contain much
sand and are usually more calcareous than the Sevier. Furthermore, they are
often characterized, particularly the Benbolt as exhibited in Raccoon Valley, by
layers of limy cobbles.

Limestones.—The western belts of the Appalachians are predominantly com-
posed of limestone which interfingers with the finer clastics of the medial belts.
(1) “Marble” is a term incorrectly applied to the calcarenites or coarse lime
sands which are a prominent feature of some of the belts, particularly those in
East Tennessee passing through Knoxville, but also prominent from Eidson
southwest to Luttrell along Clinch Mountain. These masses have caused con-
siderable difficulty in correlation because of their similarity of lithology and
fauna regardless of position. The marbles are generally composed of echinoder-
mal material, broken shells, and other organic debris. In some instances, as at
Porterfield Quarry, McNutt Quarry, Tillson Mill, and a few other places, the
calcarenites are associated with bioherms or “reefs” probably formed by bryo-
zoans. A special type related to the calcarenites is the shell breccia which forms
beds usually less than a foot, but occasionally several feet, thick. One or more
beds of this type occur in the Witten formation and generally contain the peculiar
Cryptophragmus antiquatus. This fossil is not confined to this lithology but is
commonest in it. Many other types of fine or coarse detrital limestone are present
in the Appalachians, but they do not generally form large masses. (2) Calcilu-
tites, massive or thin bedded, are one of the commonest facies of the Appalachians
and form most of the western belts. Indeed, this type of rock is so thick and so
like the Lowville of New York that the New York name was applied to nearly
the entire sequence along the Cumberland Front regardless of fossils which indi-
cated otherwise. The name Lowville as used in the Appalachians was truly a
facies term. The calcilutites form thick masses in the so-called Mosheim facies,
which occurs at several levels in the Lenoir formation, and similar bodies occur
at other levels. The fact that Mosheim-type calcilutites appeared frequently at
the base of the Lenoir gave credence to the idea that it was a continuous sheet
of rock rather than a facies. However, in one quadrangle in Virginia the Mos-
heim was mapped at three different levels, a clear indication that it is a facies
and not a formation. (3) The black limestones of Virginia as typified by the
Liberty Hall facies, and the Whitesburg formation of Tennessee are a special
type of calcilutite. These are often heavy bedded, but may be the reverse, and
are generally poorly fossiliferous. In some places they interdigitate with black
shales, as in Catawba Valley. (4) The cobbly limestones, which are generally
sandy or silty, are an eastern phase of limestone prominent in several belts in
East Tennessee and also in the Lantz Mill facies of the Edinburg formation.
The best example of this type is seen in the Arline formation and its lateral
equivalent, the Athens formation. In East Tennessee this rock is often leached
of its lime, when it appears to be a sandy shale, occasionally graptolitic, occa-

40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 127

sionally wonderfully fossiliferous, as in the vicinity of Friendsville, Tenn. (5) A
dolomitic facies is the final prominent carbonate rock facies. This type of rock
sonsisting of light-gray dolomite or dolomitic limestone is prominent at the base
of the Middle Ordovician in many belts. It is well displayed in the Blackford,
Surgener, Pamelia, Long Savannah, and other formations. These rocks, although
at the base of the sequence, are quite clearly of different age across the geosyn-
cline. This is probably true also of the Pamelia formation of New York. The
statement can be truly demonstrated in the Appalachians where the Blackford
formation is equivalent to the Lenoir, but the Surgener formation, which is like
the Blackford lithologically, contains marine fingers with fossils of the Lincoln-
shire (Hogskin member).

The facies diagrams.—Figures 2 and 3 represent ideal diagrams of the facies
relationships roughly north and northeastward from the belt along the base of
the Great Smoky Mountains to the exposures at High Bridge, Ky. The sequence
would be essentially the same if it had been taken from the same beginning point
to the Central Basin of Tennessee. The diagrams show a great wedge ranging
in thickness from 7,000 to 9,000 feet on the east to about 600 feet on the west
side. The eastern and thickest part of the wedge consists of clastics, coarse only
in the extreme eastern and upper part of the column. The main mass of the
clastics is sandy shale and sandstone, in some places limy and in others quite
shaly. In the central portion of the diagrams the sequence has become shaly
and limy with sand definitely subordinate except for the marbles which are
actually a kind of coarse sand possibly formed by a continuously growing com-
munity of crinoids and cystids. The western and tapering edge of the wedge is
composed of moderately thick and thin-bedded limestone, the so called “dove”
limestone or Lowville facies. This facies evidently covered a great shelf area that
occupied much of Tennessee and Kentucky in Ordovician days. It must be
borne in mind that these diagrams are idealized and conventionalized and are
not drawn to scale. It would be difficult to portray the facies intelligibly if the
diagrams were to scale.

Comparison with Devonian facies of New.York.—Perhaps the best exhibition
of Paleozoic facies across a geosyncline is that exhibited by the great wedge
of Middle Devonian sediments that extends from the Catskill Mountains to
Lake Erie near Buffalo. The form of the Devonian wedge is like that of the one
in Tennessee, but some differences are obvious. In the Devonian the red-bed
facies occupies nearly the entire sequence in extreme eastern New York, and
coarse conglomerates are present in the upper part of the sequence. In other
words the Devonian facies are more developed as regards the clastics than the
Tennessee wedge. It is suggested that this coarse clastic portion of the Ordovi-
cian facies is either overridden by the Great Smokies or was obliterated by
mountain-making and accompanying contemporaneous igneous intrusions.

In the Devonian wedge a great development of black shales fingers with the
sandy clastics to the east but occupies much of the section on the thinned edge
of the wedge. This condition may be due to unusual paleogeographic conditions
in the Devonian, such as a lowland to the north and west, that might have fur-

KNOXVILLE, FRIENOSVILLE, HOUK,BLOUNT = ¢
TENN. TENN. CO., TENN.
I

N_ HIGH BRIDGE,
KENTUCKY

-o— Fi —_—_ eer : aes

— =’,
——_a

—s :

————-7000 10 9000 feet

ee

OROOVICIAN WI
OATUM DRAWN
MARTINSBURG

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Fscale because of difficulties

KNOXVILLE, FRIENDSVILLE, HOUK, BLOUNT
TENN. TENN enn
NN HIGH BRIDGE,
KENTUCKY ant? Bacon
a
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SEVIER =
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LONE
CUMBERLAND MOUNTAIN, THORN HILL,

, BULLS GaP, KNOXVILLE, FRIENOSVILLE, HOUK, BLOUNT
GAP, TENN. TENN. TENN. TENN. TENN. TENN. 6o, TENN. s
i, | | lee —
N_ HIGH BRIDGE,
KENTUCKY E
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390 feet

} WIRASA\S\
34 7600 to 9000 (set

CALCAREOUS SHALY

SILTY
OROOVICIAN WEDGE WITH UPPER SAnoeyons SANDSTONE MUDSTONE

SHALE LIMESTONE
DATUM DRAWN ON BASE OF

MARTINSBURG FORMATION. Po 3
E-I=—1
SES
COBBLY “wareie” CHERTY MASSIVE

PLATY CALCAREOUS DOLOMITE CONGLOMERATE
LIMESTONE LIMESTONE Oove LIMESTONE MUDSTONE

Fic. 2—Diagram illustrating facies changes in east Tennessee and southwest Virginia from north to south. The diagram is not made to scale because of difficulties
in drawing the facies shifts in the rapidly thickening wedge south of Friendsyville.

LONE
CUMBERLAND MOUNTAIN, THORN HILL, BULLS GAP, KNOXVILLE, FRIENOSVILLE, HOUK, BLOUNT
GAP, TENN. TENN. TENN. TENN. TENN. TENN. ©. TENN,
NY HIGH BRIDGE,
KENTUCKY ent? BACON,
EVIER EVIER 3
TARDY CREEK- CAN 8 s =
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° NELSON —
8 ORYDEN RED KNOBS a
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— SS _LINGOLNSHIRE 8
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CERO,
MOSHEIM = = TELLicg
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HOGSKIN OCR
MOSHEIM SUS
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FETZER

Fic. 3.—The same facies pattern with formation names.

Ow

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west Mad

my rodine now
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PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 4I

nished the black shale. Nevertheless, black-shale development is less in the Ordo-
vician wedge at the point the section was made. Had the section been taken
through Bristol, Tennessee-Virginia, a greater development of the black shale
would have been evident, but it is doubtful if it would have the enormous extent
of that occurring in the Devonian. Furthermore, in the Devonian the black shale
intervenes between the clastics and the limestones of the shelf facies. In the
Ordovician wedge, on the other hand, cobbly limestones and limy shales with
cobbles form an intermediate stage between the clastics and the limestones. The
limestone facies is unlike that of the Devonian limestone in being composed of
lime muds, whereas the corresponding facies in the Devonian contains more
coarsely detrital limestone. Although the facies of the two periods are unlike in
these minor respects, they are actually quite similar in their major aspects and
show that a pattern existed in geosynclinal sedimentation.

The author (or authors) of each new formation name appears after the name.

Arline formation (B. N. Cooper and G. A. Cooper).—This name is taken
for a limestone formation about 400 feet thick exposed almost in its entirety on
both sides of the valley of a small stream tributary to Gallagher Creek, 2 miles
southwest of the railroad switch at Arline on the Concord (T.V.A. 138-SW)
and Louisville (T.V.A. 138-SE) Quadrangles, Tenn. The rock is mostly a
cobbly-weathering, impure limestone containing considerable quantities of fine
clastic material. It weathers by leaching of the lime to a yellow-brown soil con-
taining numerous silicified fossils. The formation is underlain by dark, cherty
limestone of the Lenoir formation and is overlain by shaly rock or calcarenite
which is usually called “Holston marble” but is now the Red Knobs formation
described herein as new.

This limestone is of restricted distribution in eastern Tennessee. It extends
northeast from its type section to Knoxville where it forms a fairly wide belt
in the south environs of the city and in the neighborhood of Shooks Gap. To
the southwest it interfingers with the silty calcareous beds of the Athens forma-
tion. Fingers of the two types of sediment can be seen associated in the vicinity
of Christiansburg, Sweetwater (T.V.A. 131-SW) Quadrangle, Tenn. South-
west of the latter place in the vicinity of Athens and southwest of Calhoun the
type Athens formation in its upper part is cobbly limestone like the Arline, con-
taining numerous trilobites and a few brachiopods having affinities with those of
the Arline formation.

In the long and wide Ordovician belt along the west front of the Great Smoky
Mountains fingers of this formation appear in the Tellico formation. These
are especially well displayed along the Chapman Highway (Tennessee Highway
71) near Cusick, Walden Creek (T.V.A. 156-SW) Quadrangle. The Ordovi-
cian belt running from Philadelphia through Concord, just west of the Friends-
ville belt, does not reveal this formation, but a shale underlying the Farragut
marble south of Philadelphia contains one of the leading guide fossils of the
Arline formation (Bimuria superba). On the west side of the syncline north
of Morristown, at St. Clair, about 300 feet of Arline is exposed on the east
side of the road in a small quarry and adjacent area. Here the formation fingers

42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

with black shale at the top, and calcarenite masses with Ptychoglypitus suggest
the Effna formation of Virginia.

In Virginia, at Marion and vicinity, the characteristic fossils of the Arline
formation occur in cobbly and shaly limestone 225 feet thick which occur above
the Maclurites beds of the Lenoir and interfinger with black shale of the Rich
Valley formation. The position of these beds and the occurrence of typical Arline
fossils elsewhere in Virginia in the Botetourt formation, as in Catawba Valley,
make it clear that these two formations are at least partial equivalents.

On the northeast side of the Saltville Thrust block at Porterfield Quarry, 5
miles northeast of Saltville, a thin remnant of the Arline formation occurs under
the Effna calcarenites and reefs. The latter contain many elements of the Arline
fauna, and the siliceous dark limestone underlying the Effna contains a suite
of species related to, but not identical with, those of typical Arline.

The following brachiopods have been identified in the Arline formation of
Tennessee (Knoxville to Friendsville) :

Atelelasma holstoni (Hall and Clarke) ?
A. perfectum Cooper

Bimuria superba Ulrich and Cooper
Camerella tennesseensis Cooper
Christiania subquadrata (Hall)

Conotreta ? alta Cooper

Cyrtonotella virginiensis Butts
Dactylogonia geniculata Ulrich and Cooper
D. obtusa Cooper

Eremotoechia cloudi Cooper

E, silicica Cooper

Glyptorthis concinnula Cooper
Isophragma biseptatum Cooper

I. extensum Cooper

I. subabbreviatum Cooper

Laticrura latibrachiata Cooper

Leptellina tennesseensis Ulrich and Cooper
Lingulasma matutinum Cooper
Lingulella sp. 4

Lingulella sp. 5

Macrocoelia obesa Cooper

Multicostella planosulcata Cooper

M. plena Cooper

M. saffordi (Hall and Clarke) ?

Opikina glabella Cooper

Orthambonites angulatus Cooper

O. blountensis Cooper

O. friendsvillensis Cooper

O. tennesseensis Cooper

Oxoplecia plicata Cooper

Palaeostrophomena superba Cooper

Paterula perfecta Cooper

Paurorthis fasciculata Cooper

P. longa Cooper

Perimecocoelia elliptica Cooper

Phragmorthis buttsi Cooper

Platymena plana Cooper

Plectorthis australis Cooper

P. compacta Cooper

Productorthis americana Cooper
(Virginia, Marion quarry)

Ptychopleurella globularis Cooper

Rhipidomena sp. 1

Schizambon irregulare Cooper

S. subradiatum Cooper

Siphonotreta americana Cooper

Sowerbyella varicostellata Cooper

Taphrorthis emarginata Cooper

Titanambonites amplus (Raymond)

Valcourea brevicarinata Cooper

Valcourea sp. 4

The thinned Arline at Porterfield Quarry in Virginia has yielded:

Leptellina transversa Cooper

Opikina matutina Cooper
Palaeostrophomena subtransversa Cooper
Sowerbyella silicica Cooper

S. silicica nana Cooper

Valcourea semicarinata Cooper

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 43

Correlation of Arline formation.—The most important elements of the brachio-
pod faunules listed above are: Bimuria, Christiania, Eremotoechia, I sophragma,
Palaeostrophomena, Phragmorthis, Platymena, and Titanambonites. These have
a wide geographic distribution, and some of them have a fair stratigraphic dis-
tribution. The Little Oak fauna of Alabama is very similar to that of the Arline
and contains nearly all the genera and many species that are very close and a
few identical ones. The Pratt Ferry fauna is related to the Arline and is prob-
ably a part of the Little Oak. The Botetourt formation of Virginia, particularly
in the Catawba Valley and on the north side of Marion, contains many of the
same species. This is true also of the Effna formation which appears to be a
reefy development of the Arline. Farther afield the lower Edinburg (Cyrtono-
tella zone) of northern Virginia and the Shippensburg formation (Pinesburg
member) of Maryland and southern Pennsylvania contain many of the Arline
genera together with some of its species. The Arline and its correlates thus
extend from Alabama to south-central Pennsylvania.

It should be mentioned here that the fauna of the Benbolt formation contains
numerous elements of the Arline fauna and is indeed the last manifestation of
that fauna, except for its return in a modified form in the Oranda formation.
The Tellico formation of East Tennessee for many hundreds of feet contains
fossils in tongues of limestone or sandstone that are undoubtedly extensions of
the Arline. It should also be mentioned that the Arline-Little Oak faunas and
their correlates are closely related to the Stinchar-Balclatchie assemblage of the
Girvan district of Scotland. The Oranda of Virginia is the final manifestation
of the Arline fauna but is modified by numerous Trenton elements such as
Cryptolithus, Rafinesquina, Calymene, Sitrophomena, and Reuschella. Elements
of the Arline fauna such as Christiania can be found all through the Edinburg
formation of northern Virginia.

Athens formation.—The Athens shale was described by Hayes (1894b) as
follows :

East of the Tennessee River the upper part of the Chickamauga limestone is replaced by
shales from 300 to 500 feet in thickness. Eastward beyond the edge of this sheet this forma-
tion increases to several thousand feet in thickness, where the strata represent the rapid and

variable accumulation of sediment near the shore.
The formation takes its name from Athens, Tennessee, on the Cleveland sheet.

In the description of the Athens “shale” on the Cleveland sheet the rock is
said to be “in some places sandy, but generally calcareous, dark-blue when fresh,
but weathering yellow.” Examination of the type section in the railroad cut
north of Athens shows the type Athens to have only a small amount of shale
near the base. The formation is mostly a silty or sandy, cobbly limestone that
weathers to a yellow sandy, shaly rock. The disintegrated rock evidently led to
the conception that the Athens is a shale. As now applied, the name Athens is
most used for black graptolite shale, completely unlike anything in the type sec-
tion. It is here proposed that the name “Athens” be restricted to the type region
where the formation proves to be a facies of the Arline formation.

At the type section of the Athens the formation rests on a thin tongue of the

44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

“Chickamauga” limestone, identified in this belt as Lenoir limestone, overlain
by a thin bed of impure limestone, the Fetzer tongue of the Arline formation
abounding in Christiania. The lower bed, like the Athens above it, is often
leached of its lime, as it is 24 miles southeast of Riceville. The lower shaly-
fracturing part of the Athens in the type section is succeeded by cobbly-weather-
ing, silty limestone abounding in trilobites.

Essentially the same sequence is shown in the superb section along the road
running parallel to the Hiwassee River, 2 to 3 miles southeast of Charleston.
Here about 170 feet of silty shale overlies sandy, oolitic beds containing calcare-
ous lenses and Christiania. These sandy shales contain graptolites and are over-
lain by calcareo-arenaceous beds strongly suggesting Sevier lithology and grad-
ing into cobbly-weathering limestone. The cobbly beds abound in trilobites,
particularly the genus Lonchodomas. These beds are overlain by shaly lime-
stone and marble containing many fossils. The upper cobbly beds yielded few
fossils besides the trilobite mentioned, but poor specimens of Christiania and
Platymena occur very close to the top of the section.

Traced to the northeast from Athens to Friendsville, the Athens formation
loses it shaly character in the lower part and becomes more limy. With the
advent of the line, fossils of the Christiania fauna become increasingly abundant.
This shift of facies is well exhibited in the neighborhood of Christiansburg on
the Sweetwater (T.V.A. 131-SW) Quadrangle. Farther north, at Friendsville,
no trace of the Athens has yet been identified. Southeast of Sweetwater along
Route 68 the cobbly zone of the Athens is well exposed and contains elements
of the Christiania fauna of the Arline limestone. Thus, followed northeast along
the strike from Athens, the Athens formation passes from cobbly and shaly beds
to wholly limestone of the Arline formation. Outside of this belt rocks called
Athens have different characters, black shale or black limestone, and actually
generally represent only a part of the type Athens to the east but include more
than that formation where the so-called Athens overlies the Arline formation.
To these manifestations of the Athens or post-Athens outside of the Athens belt
other names are here applied.

Correlation and fossils of Athens formation—lIn the vicinity of Athens and
as far south as the Hiwassee River the leached rock at the base of the Athens
yields an interesting fauna of brachiopods. Those taken from this part of the
Athens and the rest of the formation follow:

Apatomorpha pulchella (Raymond) L. tennesseensis Ulrich and Cooper
Atelelasma dorsoconvexum Cooper Orthambonites rotundiformis Cooper
Christiania subquadrata Hall Paurorthis sp. 1

Glyptorthis sp. 5 Schizotreta posteroconvexa Cooper
Isophragma ricevillensis Cooper Titanambonites amplus (Raymond)
Leptellina subcarinata Cooper T. medius Cooper

Athens shale of Georgia.—This is a thinned representative of the Paperville
formation of Cooper and Cooper (see below).

Athens shale of Alabama.—This is generally a papery black shale, in places
abounding in graptolites. It is here termed by Cooper and Cooper the Colum-

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 45

biana formation and is regarded as a lateral facies of the Little Oak formation
(see below).

Athens shale of Virginia.—This has been renamed in the Bristol area and
Catawba Valley the Paperville formation by Cooper and Cooper. The graptolite
shales in the Saltville thrust block are called Rich Valley formation by Cooper
and Cooper (see below).

Athens limestone-——The ash-weathering black limestones of Virginia, which
were called Athens by Butts, were regarded as a facies of the Edinburg forma-
tion for which Campbell’s (1905) name “Liberty Hall” was revived by Cooper
and Cooper (1946).

Attalla formation.—A coarse conglomerate at the base of the Chickamauga
limestone in Birmingham Valley, Alabama (Butts, 1911, p. 37). The conglomer-
ate is patchy in occurrence. This conglomerate, together with red and green
shales at the base of the Chickamauga which the writer includes in the name
Attalla, is suggestive of the Blackford lithology of Tennessee and Virginia but
obviously deposited at a different time than the Blackford.

Only one brachiopod, Lingulella fostermontensis (Butts), has been taken from
the shaly phase of the Attalla on the Birmingham Quadrangle.

Bacon Bend member of Sevier formation.—R. B. Neuman (1956, p. 162)
proposed this name for interbedded gray and red calcareous shale and siltstone
with some non-red beds possessing submarine slump structures. The type sec-
tion is near Bacon Bend on the Tennessee River, Vonore (T.V.A. 139-SW)
Quadrangle. The formation contains a few poorly preserved fossils:

Pionodema camerata Cooper

Rostricellula sp.
Zygospira sp.

Bays formation.—This name was proposed by Keith (1895, p. 4) for the
great succession of red beds in Bays Mountain, northeast Tennessee. These
red beds contain a considerable thickness of clean white quartzite. The Bays
is variable in thickness but in places is many hundreds of feet thick. It is also
identified in the Catawba Valley belt.

Brachiopods taken from the Bays are:

Ectenoglossa ? rubra Cooper
Pseudolingula luttrellensis Cooper

Correlation of Bays formation—Fossils taken just under the base of the
Bays formation in Tallassee Quadrangle at Fourmile Church are identified as
a new species of Pionodema (P. camerata). This suggests that the Bays rests
on rocks equivalent to part of the Witten formation. The same conclusion was
reached from fossils collected under the Bays in Bays Mountain at Guthrie Gap,
Bulls Gap (T.V.A. 171-SE) Quadrangle, where Zygospira occurs. The earliest
known appearance of this fossil elsewhere in the Appalachians is in the Witten
formation.

Benbolt formation.—This formation was described by B. N. Cooper and
C. E. Prouty (1943, p. 868), and its type section was designated as exposures

46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

14 miles south of Benbolt west of the Tazewell County Farm. At its type sec-
tion the formation consists of two members both composed of limestone, the
lower one called Shannondale limestone and the upper one known as the Burkes
Garden member. These member names have not been used far outside the con-
fines of the county. The Benbolt is separated from the overlying Wardell forma-
tion by the Gratton formation. The Benbolt is characterized by numerous dis-
tinctive fossils that are confined to this level as far as known. These fossils make
it possible to identify the Benbolt interval in belts in which the lithology is quite
different from that of the type section. The Benbolt, as indicated by its distinc-
tive fossils, is widely distributed in southwestern Virginia and northeastern
Tennessee. Traces of the fossils occur as far north as southern Pennsylvania and
as far south as Georgia.

Benbolt formation in Virginia.—In the Cumberland Front sequence in extreme
southwest Virginia the Benbolt is not typically developed, but a probably partial
equivalent is the Hurricane Bridge limestone. At the north end of the St. Clair
fault block the Benbolt is typically developed and is composed chiefly of limestone
as described for the type section. To the southwest the Benbolt becomes a soft
shale and cobbly limestone abounding in exceptionally well preserved fossils. The
Clinch Mountain belt contains an excellent sequence of this formation which
here is a soft gray shale. In some of these belts the Gratton limestone is absent,
with the result that it is usually difficult to draw a satisfactory boundary between
the Benbolt and Wardell formations. The two combined formations are then
called Dryden formation, but it is usually possible to recognize Wardell elements
in the upper part and Benbolt species in the lower part.

In the Saltville fault block the interval of the Benbolt plus part of the Ward
Cove is represented by black limestone, here called Chatham Hill formation, but
a sufficient number of Benbolt fossils is preserved in these dark limestones to
distinguish the presence of the formation. In west-central and northern Vir-
ginia the Middle Ordovician sequence is dominated by the Edinburg formation.
At the base of this formation is a zone characterized by cobbly and black lime-
stone containing Benbolt fossils intermingled with those characteristic of the
Arline formation. For example, Dinorthis transversa is present in the Cyrtono-
tella and Nidulites zones of the Edinburg formation and in the lower part of the
Shippensburg formation (Pinesburg member) of Pennsylvania and Maryland,
which is a partial equivalent of the Edinburg. The same Dinorthis together
with characteristic fossils of the Arline fauna betray the presence of Benbolt
equivalents in the dark limestones exposed in the Eagle Rock (15’) Quadrangle.

Benbolt formation in Tennessee.—The extension of the Clinch Mountain belt
into Tennessee exposes the Benbolt formation in its shaly facies for many miles.
It is also well displayed as a shale, often with limy cobbles and thin layers of
limestone in Beaver, Raccoon, and Hogskin Valleys. In the vicinity of Lone
Mountain, shale at the interval of the Benbolt appears to contain a fauna with
Wardell as well as Benbolt faunal elements intermingled to such an extent that
the term Benbolt is inapplicable and Dryden is used as in Virginia. In the Clin-
ton belt the formation has lost its individuality.

PART. I CHAZYAN AND RELATED BRACHIOPODS—COOPER 47

In the Knoxville region and to the south Benbolt faunal elements appear in
the lower part of the Ottosee (=Sevier) shale. Benbolt fossils appear in the
upper part of the Sevier along the west front of the Great Smoky Mountains in
a sandstone (No. 5) above the Chota sandstone of Neuman.

In northwestern Georgia thin-bedded limestone separated by layers of shale
occurs on U. S. Highway 27 just north of Chickamauga Creek. Mimella and a
few other species here are suggestive of the Benbolt, but the sequence has been
placed tentatively in the Ridley formation.

Brachiopods are abundant in most localities of the Benbolt. The greatest
variety occurs in the lower beds near the contact with the subjacent formation.
Here occur genera and species reminiscent of the Arline fauna. In the higher
shales specimens are usually more scattered and some appear in the limy cobbles
that often make up a substantial part of the formation. Brachiopods are:

Acanthocrania grandis Cooper

Atelelasma planum Cooper

Bellimurina sp. 1

Camerella sp. 1

Chaulistomella brevis (Willard)

C. elongata (Willard)

Cyrtonotella crassicostella
(Schuchert and Cooper)

C. fasciculata Cooper

C. subquadrata Cooper

Dactylogonia sp. 1

Dactylogonia sp. 3

Dactylogonia sp. 6

Dinorthis interstriata Willard

D. transversa Willard

D. transversoides Cooper

Eremotrema biconvexa Cooper

Fascifera convexa Cooper

F. stonensis (Safford)

Glyptorthis rara Cooper

G. uniformis Cooper

G. uniplicata Cooper

Hesperorthis multicostata Cooper

Tsophragma biseptatum Cooper

Leptellina platys Cooper

L. pulchra Cooper

L. sublamellosa Cooper

Lingulella virginiensis Cooper

Lingulella sp. 11

Macrocoelia magna (Butts)

M. rotunda Cooper

Mimella globosa (Willard)

M. sulcata Cooper

Murinella cancellata Cooper ?

M. muralis Cooper

M. plana Cooper

Oligorhynchia bifurcata Cooper
Oligorhynchia sp.

Opikina parvula Cooper

Opikina pulchella Cooper

Opikina sp. 1

Orthambonites parvicrassicostatus Cooper
Oxoplecia multicostellata Cooper

O. parva Cooper

Pachyglossa pachydermata Cooper
Palacostrophomena resupinata Cooper
Paurorthis ponderosa Cooper
Perimecocoelia semicostata Cooper
Pionodema crassipunctata Cooper
Plectocamara aseptata Cooper

P. sulcata Cooper

Plectoglossa sp. 1

Plectorthis tenuis Cooper

Protozyga uniplicata Cooper
Ptychopleurella uniplicata Cooper
Rhipidomena tennesseensis (Willard)
Rostricellula rostrata Ulrich and Cooper
Schizambon macrothyris Cooper
Skenidioides mediocostatus Cooper
Sowerbyella compacta Cooper
Strophomena anomala Cooper

Faunal discussion and correlation of Benbolt formation.—The Benbolt fauna
is essentially a transitional assemblage because it contains elements of the Arline
and equivalent faunas and at the same time elements of the overlying Wardell
assemblage. The basal beds of the Benbolt are the parts that contain most of
the elements related to the Arline fauna such as Palaeostrophomena, Cyrtono-

48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

tella, Isophragma, Paurorthis, Perimecocoelia, and Rhipidomena. This is the
last appearance of Cyrtonotella, Isophragma, Perimecocoelia, and Rhipidomena.
Wardell elements are: Fascifera, Murinella, Pionodema, Rostricellula. The
Benbolt is not the earliest appearance of any of the genera just mentioned ex-
cept Pionodema, but these genera are abundant in the Wardell and fairly char-
acteristic of it, except for Pionodema. The assemblage that appears in the Arline
is thus terminated in the Benbolt, and thereafter a marked faunal change takes
place. After the Benbolt the faunas contain elements of the Trenton such as
Strophomena, Doleroides, Zygospira, and Pionodema.

Benner limestone.—This formation (Kay, 1944, p. 15) is composed of well-
bedded limestone 14 to 190 feet in thickness. It is present throughout central
Pennsylvania and southeastward to the western belts of Cumberland Valley. The
type section is at Union Furnace although the name is from a township in Centre
County. The formation is composed of two members; the lower one is the
Snyder limestone and the upper is the Stover limestone. These two names should
be consulted for details.

Hallina lirata Cooper is recorded from the undivided formation. The Benner
is regarded as a correlate of the Witten formation of Virginia and Tennessee.

Ben Hur formation.—This formation was proposed by Miller and Brosge
(1950) and consists of yellowish-gray limestone and yellow to buff, drab mud-
stone about 180 feet in thickness. The middle portion of the formation is marked
by a few limy layers with Camarocladia. This formation was named for an ex-
posure in the L. and N. RR. cut west of Ben Hur, Ben Hur (T.V.A. 170-NE)
Quadrangle, Va. The following brachiopods are known:

Pionodema minuscula (Willard)
Strophomena sp.
Zygospira sp.

Blackford formation.—Butts proposed this name for a series of conglomer-
ates, red beds, gray shales, dolomites, and chert beds which overlie the Knox
dolomite at Blackford, Russell County, Va. These beds were overlain by a
vaughanitic limestone or calcilutite identified by Butts as Mosheim limestone.
The Blackford was originally defined as a facies of the Murfreesboro formation
which was thought to overlie the Knox and underlie the Mosheim.

Subsequent work on the Blackford indicates that it does not correlate with
the Murfreesboro limestone of the Central Basin of Tennessee. Cooper and
Prouty (1943, p. 862) therefore graduated Butts’ term to their Cliffield forma-
tion where it formed the lowest member. The member as described by Cooper
and Prouty is a composite containing separable units. The Blackford therefore
has undergone further revision. The upper “blocky chert’’ was separated as the
Elway formation (B. N. Cooper, 1945b, p. 42). In some areas the Blackford
contains calcarenites with Rostricellula that are recognizable as, and referable
to, the Lenoir formation. These, too, have been named. Blackford has thus be-
come a name of little use. It may be applied to basal shales, dolomites, and
conglomerates, but these are often demonstrably of different age in different
belts. The name is therefore of little use in Appalachian stratigraphy in any

|

}

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 49

other sense than a facies term except in its type belt. (See Elway and Tumbez
for faunal lists.)

The supposed equivalence of Murfreesboro and Blackford is explained under
the Chickamauga limestone. The varying age of the Appalachian Mosheim fixed
the ages of underlying beds. It takes no imagination in examining faunal lists
said to be from the Murfreesboro of the Appalachians to understand that the
Blackford is not the same from place to place. It is an odd fact that no uni-
formity of faunas has been detected in this member. Few brachiopods have been
taken from the restricted Blackford:

Camerella sp. 2
Obolus sp. 2

Blockhouse formation (R. B. Neuman (1956, p. 148).—This name is pro-
posed for dark-gray to black calcareous shale containing graptolites, exposed in
the belt along the base of the Great Smoky Mountains in East Tennessee and
best seen on the Blockhouse (T.V.A. 148-NW) Quadrangle where the type
section is located. The formation ranges from 175 to 500 feet in thickness. It
correlates with part of the Athens formation, probably the lower part. The
Blockhouse shale rests on the cobbly Fetzer, a tongue of the Arline formation.
Few brachiopods have been taken:

Paurorthis catawbensis (Butts)

Botetourt formation.—Cooper and Cooper (1946, p. 80) proposed this name
as a member of the Edinburg formation for brown-weathering, impure granular
limestone overlying the Lincolnshire formation. The type section is on the hill-
side 4 mile south of Dunkard Church and 6.9 miles S. 80° W. of Natural Bridge,
Va. This member, now made a formation, is prominent and easy to identify in
many localities in central Virginia, but it was identified with some difficulty in
northern Virginia, although many species of the member occur in granular lime-
stone at the base of the Cyrtonotella zone. An excellent development may be
examined in Catawba Valley northeast of Blacksburg where it underlies or
fingers with calcarenites of the Effna formation. The member is here given
formation rank.

The Botetourt can be recognized in parts of Tennessee as at the type section
of the Whitesburg of Ulrich. At this place it overlies the Lenoir and occurs at
the base of Ulrich’s Whitesburg formation. It is identifiable at Mosheim and at
Albany, Tenn.

At Edinburg Dam section about 1 mile below Edinburg and at Tumbling Run
14 miles southwest of Strasburg, Va., dark thin-bedded limestone occurs between
granular beds thought to be Botetourt and the cherty Lincolnshire. These con-
tain the trilobite Cybelloides and brachiopods such as Cristifernia that are
clearly of post-Lincolnshire affinities. These beds are here placed in the Botetourt
formation.

The following brachiopods have been taken from the Botetourt formation:
Acanthamboma virginiensis Cooper Bilobia virginiensis Cooper
Atelelasma sp. 2 Bimuria immatura Cooper

50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

B. superba Ulrich and Cooper
Camerella minuta Cooper
Christiania subquadrata (Hall)
Conotreta ? altirostra Cooper

C. multisinuata Cooper
Cyrtonotella grandistriata (Willard)
C. virginiensis Butts
Cyrtonotella sp.

Dactylogonia transversa Cooper
Dactylogonia sp. 2

Doleroides ? ponderosus Cooper
Elliptoglossa ovalis (Bassler)
Eoplectodonta ? dubia Cooper
Glossella sp. 1

Glyptorthis equiconvexa Cooper
Hesperorthis ? costellata Cooper
Hesperorthis sp. 1

Isophragma biseptatum Cooper
Kullervo punctata Cooper
Leptellina pulchra Cooper

L. tennesseensis Ulrich and Cooper
Limbimurina brevilimbata Cooper
Multicostella bursa (Raymond)
Opikina ? dubia Cooper
Orthambonites brachiophorus Cooper
O. parvicrassicostatus Cooper

O. tennesseensis Cooper

O-xoplecia holstonensis Willard
Pachyglossa pachydermata Cooper
Palaeostrophomena angulata Cooper
P. ? rugosa Cooper

Paterula perfecta Cooper

Paurorthis catawbensis Butts
Perimecocoelia semicostata Cooper
Productorthis americana Cooper
Ptychoglyptus virginiensis Willard
Scaphorthis perplexa Cooper
Schizambon cuneatum Willard
Schizotreta shuleri (Willard)
Taphrorthis peculiaris Cooper

Correlation of Botetourt formation—The fauna of the Botetourt forma-
tion is clearly related to that of the Arline and Effna formations. Ptychoglytus,
Kullervo, Leptellina pulchra, Oxoplecia holstonensis, and Perimecocoelia empha-
size this correlation.

Bowen formation.—This formation was named by Cooper and Prouty (1943,
p. 876) from Bowen Cove at the northwest base of Short Mountain, Tazewell
County, Va. It consists of about 60 feet of brown sandstone and red mudrock
often exquisitely mudcracked lying between the Wardell and Witten formations.
The Bowen has been identified extensively in southwestern Virginia and parts of
northeastern Tennessee. The formation has not yet produced any brachiopods.

The Bowen formation was thought by Butts to be the initial stage of the Mocca-
sin formation, but Cooper and Prouty (1943, p. 877) show that Campbell did
not include this red bed in his definition of the Moccasin formation. Witten
and Wardell may be difficult to separate where the Bowen is absent.

Burkes Garden member of Benholt formation.—This member was named
by Cooper and Prouty (1943, p. 869) from Burkes Garden Creek south of Gose
Mills, Tazewell County, Va. The rock is mostly argillaceous, crinoidal, and
bryozoan-bearing limestone. The lower beds abound in ramose bryozoans. The
member is variable in thickness, ranging from 50 to approximately 100 feet. In
Thompson Valley and Burkes Garden cross-bedded calcarenites are present, at-
taining about 100 feet in thickness in the latter place. The member is absent in
the Clinch and Bluestone valleys.

Brachiopods listed from the member (Cooper and Prouty, 1943) are:

Campylorthis sp. = Chaulistomella sp.
Dinorthis cf. D. quadriplicata Willard
D. transversa Willard

*Glyptorthis bellarugosa (Conrad)
“Leptaena” aff. L. palustris Willard = Dactylogonia

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 51

Mimella superba Butts

Opikina “minnesotensis” (N. H. Winchell)

Paurorthis sp.

Planidorsa sp. = Cyrtonotella sp.

Ptychoglyptus sp.

“Rafinesquina” cf. R. obsoleta Butts

Sowerbyella aff. S. aequistriata Willard

Strophomena tennesseensis Willard = Rhipidomena tennesseensis (Willard)

Cane Creek formation (B. N. Cooper and G. A. Cooper).—Mostly thin-
bedded gray to dove limestone weathering to light gray, the layers of limestone
often separated by thin shale partings. The sequence contains several bentonites,
especially two thick ones near the top. One of these, 3 feet thick, is about 2
feet below the top, but the other 2 to 8 feet thick occurs 42 feet below the top. A
bentonite about 1 foot thick occurs at the base of the section. The entire forma-
tion is about 150 feet thick. A greenish mudstone bed 30 feet thick occurs 13
feet from the base. The type section is along the L. and N. RR. east of Cane
Creek and approximately 4 mile west along the railroad from Ben Hur Station,
Ben Hur (T.V.A. 170-NE) Quadrangle, Lee County, Va.

Brachiopods are fairly common in the upper part of the formation between
the two thick bentonites. The following species occur:

Chaulistomella lebanonensis Cooper
Doleroides tennesseensis Cooper
Opikina sp.

Pionodema sulcata Cooper
Strophomena sp.

Zygospira sp.

Carlim limestone.—The discriminating work of Kay (1944, p. 20) has
shown this formation of Butts (1918, p. 526) to be a composite one. Kay states
that “the Carlim limestone is the upper Loysburg plus the Hatter in its type
locality.” In his original publication Butts also named the Lemont member of
the Carlim formation which formed the top. The Carlim formation was said
to overlie the Bellefonte dolomite and underlie the Lowville limestone. Its posi-
tion inferior to the Lowville limestone led to assigning a Chazyan age to the
Carlim limestone.

The fact that the Carlim limestone consists of distinct units is not the only
difficulty in understanding it. The Lemont member at the top is usually the
Hostler of Kay rather than the type Lemont which occurs in a position much
higher (Nealmont) than the Carlim. Occurrence of Maclurites in the Lemont
and Hostler and the insistence that this fossil must be Chazyan added to the
confusion.

Published lists of fossils from the Carlim limestone and Butts’ collections in
the National Museum indicate that the Carlim is actually not Chazyan at all.
In view of the confusion all around it seems best to drop Carlim in favor of the
units recommended by Kay: Loysburg and Hatter. Faunal lists are cited
under these names.

Carters formation in the Appalachians.—(See Chickamauga limestone.)

52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Centre Hall member of Nealmont formation.—The original spelling of
this name by Field (1919, p. 417) was incorrect. Kay altered the spelling to
conform, as above, with that of the county and village. Although Field pro-
posed the name as a formation, Kay has lowered its rank to one of the members
of his Nealmont formation. The Centre Hall member is distinguished from the
underlying Oak Hall member by its thinner-bedded and more shaly character.
A fairly imposing list of brachiopods has been identified from the member, but
some of the identifications seem incorrect. The member has been placed in the
early Trenton and correlated with part of the Rockland formation. The list of
brachiopods does not wholly support this contention. Valcourea has not been
seen this high elsewhere, nor has Parastrophina hemiplicata been seen below
the Oranda. The identification of Sowerbyella punctostriata is probably incorrect.
The brachiopods identified are:

Ancistrorhyncha sp. O. wagneri (Okulitch)
*Doleroides pervetus (Conrad) Parastrophina hemiplicata (Hall)
*Glassia sp. Rhynchotrema sp.
*Glyptorthis sp. cf. G. bellarugosa (Conrad) *Sowerbyella punctostriata (Mather)
Hesperorthis tricenaria (Conrad) Strophomena sp. cf. S. filiterta (Hall)
*Leptaena sp. cf. L. charlottae Winchell and Strophomena sp.

Schuchert = Limbimurina *Valcourea sp. cf. V. loricula (Hall)
*Opikina inquassa (Sardeson) Zygospira recurvirostris (Hall)

O. minnesotensis (N. H. Winchell)

Chambersburg formation.—This, like some other thick formations of the
Appalachians, has been revised and reorganized to such an extent that the name,
when used at all, really takes the form of a group term. This is now especially
true of the Chambersburg formation. It was first revised by Butts, then by
Cooper and Cooper, and finally by Craig, who completely split up the old forma-
tion and did not use the name Chambersburg.

As originally defined the formation included about 150 feet of calcilutite at
the base which was correlated to the Lowville formation. The Chambersburg
above this basal part was thought to belong to the Black River. Butts (1940b,
p- 195) excluded the Lowville part from the formation. In 1946 Cooper and
Cooper defined the Oranda formation and separated it from the top of the Cham-
bersburg formation. In 1949 Craig made an exhaustive study of the Middle
Ordovician rocks above the Stones River group in south-central Pennsylvania.
His studies led to a complete revision of the formation. Butts’ Chambersburg
was divided into two formations: The Shippensburg and Mercersburg forma-
tions. Each of these formations in turn was subdivided into three and two
members respectively. Craig’s divisions have not been carried into Virginia and
West Virginia, but some of his formations are certainly there. In the vicinity of
Strasburg, Va., it is possible to recognize part of the Shippensburg formation,
and the upper massive beds just below the Oranda formation suggest some
part of the Mercersburg formation. This subject is discussed further under the
Edinburg formation.

In Virginia, Cooper and Cooper felt that the removal of the Lowville and
Oranda from the Chambersburg formation so altered the stratigraphic value of

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 53

the name that it no longer was of use in that State. Cooper and Cooper there-
fore proposed the name “Edinburg formation” which is the Chambersburg
formation minus Oranda and Lowville but including some uncertain layers at
the bottom: Botetourt and Cybeloides bed.

Butts believed that the Chambersburg in Virginia was superposed on the
Athens limestone which he had identified in northern Virginia. Cooper and
Cooper, however, contend that the Chambersburg and Virginia Athens (now
Liberty Hall) are facies of each other. This subject is pursued at greater length
under the Edinburg formation.

The brachiopods of the Chambersburg formation are listed under the new
and more restricted units of Craig, and Cooper and Cooper.

Chatham Hill formation (B. N. Cooper and G. A. Cooper).—This forma-
tion is named from exposures adjacent to Viriginia Highway 16 along the lower
northwestern slopes of Walker Mountain. The base of the formation is gen-
erally not well exposed and is transitional with the underlying black graptolitic
shales (Rich Valley formation), but the top is prominently defined by the suc-
ceeding ledges of calcarenite forming the lower part of the Wassum formation.
The total thickness is about 450 feet in the type section 2 miles south of Chatham
Hill, Chatham Hill (T.V.A. 218-NE) Quadrangle. The upper 150 feet is cherty,
dark bluish-gray limestone containing Echinosphaerites, Calliops strasburgensis,
and Nidulites pyriformis, as well as numerous brachiopods. The lower beds
are not so fossiliferous but contain Lonchodomas, Robergia, and Bronteopsis.
Generally just above the thin zone with Nidulites a few beds are crowded with
gastropods like those in the Peery limestone. The Chatham Hill formation thus
includes part of the Ward Cove, the Peery, and the Benbolt formations of Taze-
well County, Va.

Anisopleurella inaequistriata Cooper L. sublamellosa Cooper

Bimuria parvula Cooper Mimella bursa (Raymond)
Camerella immatura Cooper Opikina nasuta Cooper

C. minuta Cooper Orthambonites bellus Cooper
Conotreta multisinuata Cooper O. parvicrassicostatus Cooper
Cristiferina cristata Cooper Oxoplecia multicostellata Cooper
Cyclospira sulcata Cooper Plectocamara rotunda Cooper
Ectenoglossa nymphoidea Cooper Scaphorthis virginiensis Cooper
Glyptoglossa sp. 1 Skenidioides mediocostatus Cooper
Glyptomena sculpturata Cooper Sowerbyella nasuta Cooper
Glyptorthis bellatula Cooper S. perplexa Cooper :
Leptellina bella Cooper Trematis ? parva Cooper

Correlation of Chatham Hill formation—The brachiopods listed from this
formation are obviously related to those of the Arline, Effna, Botetourt, and
Pratt Ferry formations, but in addition some Benbolt types appear. Similarity
to the Edinburg formation is also evident.

Chickamauga limestone.—Except for Butts’ use of the name Chickamauga
in Alabama, this designation has long since passed into disuse. The name was
so broadly used throughout the Southern Appalachians that it lost its value
when the Middle and Upper Ordovician limestones and shales were studied in

54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

detail. As originally defined by Hayes for exposures in the valley of West
Chickamauga Creek, the Chickamauga limestone embraced all the strata be-
tween the Knox and the Rockwood formations. This included what is now
known as the Murfreesboro, Lenoir, Mosheim, Lebanon, Lowville, Trenton,
and Upper Ordovician.

It is of interest to point out the composition of the type Chickamauga because
of the interpretation put on it by Dr. Butts. Northwestern Georgia is one of the
areas of the Chickamauga limestone in which Dr. Butts discovered that the “Mos-
heim” limestone overlies the Murfreesboro limestone and that the Lenoir of the
Appalachians is equivalent to the Ridley limestone of the Central Basin. This
correlation, however, has caused a great deal of mischief.

The location in which these views were established is in the long sequence
exposed at intervals along the road from Pond Spring to Catlet Gap, Kensing-
ton (T.V.A. 106-SE) Quadrangle, Ga. On the south bank of West Chicka-
mauga Creek and on the east side of the bridge about 3 mile south of Pond
Spring, limestones occur which contain numerous large Leperditia interbedded
with calcilutites that weather to a white-crusted surface. These limestones have
the lithology and some of the fossils of the Murfreesboro and were so correlated
by Butts. The ostracod beds are succeeded by calcilutite, massive and strongly
resembling the Mosheim. This bed was identified as Mosheim by Dr. Butts who
thus established the position of the Mosheim above the Murfreesboro. The
“Mosheim” bed is overlain in this section by dark limestones containing black
chert and specimens of the gastropod identified as Maclurites magnus by Dr.
Butts. Because of the black chert and the gastropod this limestone was linked
to the dark chert- and Maclurites-bearing limestones of the Southern Appa-
lachians regardless of other considerations and disregarding the fact that the
chert contained Tetradium like T. cellulosum. Because of its occurrence above
the Murfreesboro, this dark limestone was correlated with the Ridley limestone
of the Central Basin which also contains Maclurites. This was done in spite of
the fact that the chert and other fossils in true Ridley are quite different from
those in the type Chickamauga limestone.

Just north of the intersection of the Catlet Gap road and the road to Davis
Crossroads, and lying on the Maclurites beds, are calcareous shaly limestones
containing Fascifera in abundance. These were correlated with Lebanon by Dr.
Butts. The presence of the latter genus is a link to the true Ridley of the Cen-
tral Basin area rather than to Lebanon. The Fascifera beds are followed by thin-
bedded limestones which are probably of Ridley age because they contain
Mimella and Chaulistomella. They are well exposed in a quarry on the west
side of the Catlet Gap road about half a mile south of the intersection mentioned
above where many Wardell-Ridley types occur: Ancistrorhyncha, Opikina
speciosa, Doleroides, Hesperorthis australis, and Protozyga rotunda. Typical
Lebanon thin-bedded limestone with yellow shaly partings and containing
Hesperorthis and Sowerbyella in abundance occurs beside the road 0.7 mile south
of the Catlet Gap-Davis Crossroads road intersection and for 0.3 mile farther
south.

PART, I CHAZYAN AND RELATED BRACHIOPODS—COOPER 55

Above the Lebanon, exposures are poor and infrequent. Limestone with
Tetradium in abundance occurs 1.35 miles south of the intersection beside a
small stream in a pasture on the west side of the road. This limestone is sug-
gestive of some seen in the Moccasin or Carters. Undoubted Trenton with
Hebertella frankfortensis was seen in a bluff on the south side of the same brook
where the Tetradium beds were seen.

The section just described is herein somewhat differently interpreted. The
lowest beds containing Leperditia are truly Murfreesboro limestone, but to this
formation would be assigned the so-called Mosheim and the overlying Maclurites-
bearing beds as well. The type Murfreesboro limestone of the Central Basin con-
tains much black chert and also has rare Maclurites. Therefore, all these cherty
beds, the Mosheim, and the Murfreesboro are correlated with the Murfreesboro
limestone of the Central Basin area.

The shaly beds containing Fascifera are thought to be Ridley (Pierce) because
this is the only horizon for this genus in the Central Basin. The higher beds
containing Mimella and rare Doleroides suggesting Lebanon probably also be-
long to the Ridley. These beds, like those below, have the lithology of the Pierce
and suggest that the characteristic massive Ridley limestone of the Central Basin
is represented eastward by shalier beds. In addition to Mimella, which occurs
only in the Pierce in the Central Basin, Ancistrorhyncha, a common Ridley fossil,
is frequent in the lower layers of the quarry mentioned above. The Sowerbyella
beds are quite characteristic of the Lebanon. This brachiopod is characteristic
of the Lebanon in the Central Basin and is extremely rare in any of the Stones
River beds outside the Lebanon. The Tetradium beds are thought to be Carters.

In Alabama, in the belts west of the Cahaba Coal Field area, the name ‘“‘Chicka-
mauga limestone” has been used in the maps of the U. S. Geological Survey
(Birmingham, Bessemer). As in Georgia, the name really is not that of a
formation, but is a group term embracing several distinguishable formations. Ac-
cording to Butts (1927, p. 7) fossils taken from the Chickamauga limestones of
Alabama were identified by Ulrich, who recognized in them representatives of
the Stones River group, Black River (Lowville) limestone, and Trenton lime-
stone. In these identifications Butts and Ulrich appear to be mistaken. It is be-
lieved by the present writer that the so-called Stones River and Black River
limestones actually represent part of the true Stones River and the Carters lime-
stones of the Central Basin sequence. The overlying Trenton limestones can
also be related to Trenton strata of the same region. In the quarry at Gate City,
Leeds (15’) Quadrangle, fossiliferous limestones containing representatives of
the Lebanon and Carters formation are overlain by Trenton (Curdsville).

In the Birmingham and Bessemer quadrangles, the Chickamauga limestone
is marked by a basal conglomerate, the Attalla conglomerate, 20 to 40 feet thick
and containing angular to subrounded pebbles of chert. The rock varies from a
coarse sand to a coarse conglomerate. In places, as at Foster Mountain, the
lower part of the “formation” (about 25 feet) is composed of shale often mottled
or streaked with purple and containing a medium-sized Lingulella (L. foster-
montensis (Butts) ) and suggesting the Blackford formation.

56 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

The name “Chickamauga” is no longer a useful formation name because the
limestone can be broken into recognizable formations to which the names from
the Central Basin may be applicable. The Chickamauga is probably not synony-
mous with the Pelham limestone proposed by E. A. Smith a year earlier.

Chota formation (R. B. Neuman, 1956).—This name was introduced for
the “Sandstone lentil in the Sevier,’ described by Keith, in the belt along the
Great Smoky Mountains in East Tennessee. The formation consists of gray
sandstone for the most part, calcareous in places, 550 to goo feet thick. The
Chota occurs just under a sandstone containing Dinorthis transversa Willard.
On the basis of this occurrence the formation is placed opposite the Benbolt
formation of western belts.

Cliffield formation.—This name was proposed by Cooper and Prouty (1943,
p. 862) for a succession of limestone beds which made a convenient unit for
mapping purposes. The formation northwest of Clinch Mountain was divided
into five members: Blackford, Five Oaks, Lincolnshire, Ward Cove, and Peery.
Subsequent studies have shown that each of these members is best recognized
as a formation; consequently, the brachiopods from each are listed under the
respective names.

Cliffield group.—Under this heading B. N. Cooper (1944, p. 54-69) groups
rock units equivalent to the aggregate of members under the Cliffield formation.
These are Blackford, Five Oaks, Lincolnshire, Effna, Whitesburg, Athens, and
Peery. It will be seen from this listing that the position of the Ward Cove is
occupied by three units, Effna, Whitesburg, and Athens, of unlike character. The
brachiopods of these units are discussed under the Effna and Rich Valley
formations.

Clover member of Loysburg formation.—This is the top member of the
Loysburg formation in central Pennsylvania. The name was proposed by Kay
(1944, pp. 4-6) for sublithographic limestone, 40 to 80 feet thick, interfingering
with the magnesian rock of the Loysburg formation and underlying the Hatter
formation. The member to date has produced no brachiopods.

Collierstown formation.—This unit was named by Cooper and Cooper
(1946, p. 60) for Collierstown on Collier Creek, west of Lexington, Va. The
type section is just north of Virginia State Highway 241, 2 miles east of Col-
lierstown. This limestone consists of a maximum of 75 feet of shell limestone
and calcarenite with minor parts of buff shale and argillaceous limestone. It is
known only in the westernmost belt of Middle Ordovician limestone along the
base of Little North Mountain. The limestone is crowded with a few species of
poorly preserved brachiopods, among them Rafinesquina.

Cyclospira sp. Rafinesquina trentonensis (Conrad)
Doleroides sp. Zygospira sp.

Correlation of Collierstown formation.—The Collierstown formation occupies
the same stratigraphic position in the southern part of the Shenandoah Valley
as the Oranda formation in northern Virginia. It also has a similar position to
the Cane Creek formation.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 57

Columbiana formation (B. N. Cooper and G. A. Cooper).—In southeastern
belts of the Appalachian Valley in Alabama, the Pratt Ferry limestone is suc-
ceeded by a body of black graptolitic shale varying in thickness from a few
inches up to 325 feet. The variation in thickness of the shale reflects the major
disconformity between it and the overlying Devonian Frog Mountain sandstone.
The Columbiana shale is approximately the same as the Rich Valley shale of Vir-
ginia and the Paperville shale of the Bristol district of Virginia and Tennessee.
The profusion of graptolites in the Columbiana shale has been described by
Decker (1952, pp. 14-26) from exposures near Pratt Ferry, Blocton (15’)
Quadrangle, Ala. The type section of the Columbiana formation is just west of
Simpson Spring, 24 miles northwest of Calera. The name is from the Colum-
biana (15’) Quadrangle in which the east side of Calera is located.

Brachiopods are rare in the black shales, and only one is listed from the
Columbiana formation :

Lingulella tenuitesta Cooper.

Curtin formation.—This formation (Kay, 1944, p. 19) is exposed in parts
of Centre, Clinton, and Lycoming Counties, Pa., and ranges in thickness from
o to 150 feet. The formation is composed of two members: Valley View and
Valentine. (See further discussion under these headings. )

Dot formation.—This name was proposed by Miller and Brosge (1950) for
dolomitic limestone, reddish and green mudstone, dove-gray limestone, and light-
gray dolomites with a prominent conglomeratic zone of chert and dolomite peb-
bles at the base. The name is from exposures along Virginia State Highway
70 just west of Dot, but the type section is from the blind spur at the south end
of the railroad cut at Hagan, Rose Hill (T.V.A. 161-NE) Quadrangle. No
fossils were seen or have been reported.

Correlation of Dot formation—Only lithology and position can be used to
correlate this formation. Lithology indicates a correlation with the Blackford
facies at the base of the Middle Ordovician sequence in western Virginia, but
its position indicates that the Dot formation is probably a correlative of the
Lincolnshire-Elway formations.

Douglas Lake member of Lenoir formation.—This name was proposed
by Josiah Bridge for exposures at Douglas Lake Dam. The rocks are an argil-
laceous dolomite attaining a maximum thickness of 30 feet and usually conglom-
eratic at the base. The type section is 14 miles upstream from Douglas Dam,
near Shady Grove on the Kykers Ferry (T.V.A. 156-NE) Quadrangle. The
Douglas Lake dolomites underlie Lenoir limestone with Rostricellula, The mem-
ber is patchy in occurrence. The facies is like that of the Blackford which dis-
places the Lenoir to the west.

Doylesburg member of Shippensburg formation.—This member overlies
the Fannettsburg member of the Shippensburg formation and is unconformably
overlain by the Nealmont formation. The member was named by Craig (1940,
Pp. 727) with its type section 1 mile S. 70° W. of St. Thomas, Pa. The forma-
tion consists of dove, massive, white-weathering limestone in the eastern belts,

58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

but interfingers with fine- to medium-grained, platy limestone with beds of dove
limestone conglomerate. The member ranges in thickness from 40 feet south-
west of Doylesburg, Pa., to 6 feet at Rockdale, northwest of Williamson, Pa.
The member is absent in the eastern belts. The Doylesburg member is especially
characterized by Cryptophragmus and Tetradium cellulosum. Brachiopods are
few:

*Mimella sp.
Zygospira recurvirostris (Hall)

Correlation of Doylesburg member—Cryptophragmus and Zygospira are a
combination suggesting correlation with the Witten formation and the Lantz
Mills facies of the Edinburg formation.

Dryden formation (B. N. Cooper and G. A. Cooper).—This name is used
for the combined Benbolt and Wardell formations where they are not separated
by the Gratton formation. The type section is in the fields on both sides of the
highway about 1 mile east of Dryden and less than 1,000 feet west of Stallard
Ford bridge across Powell River, Keokee (T.V.A. 178-SW) Quadrangle, Lee
County, Va. This formation consists mostly of limestone but may contain con-
spicuous amounts of shale, as at Rye Cove and Lone Mountain. It attains a
thickness of 300 to 500 feet. The formation occurs in the western belts of Vir-
ginia and East Tennessee. It is usually fairly easy to identify the Benbolt or
Wardell portions of the sequence in the lower and upper parts, respectively, but
to find the boundary line between the two is more difficult. Usually the zone of
Dinorthis transversa denotes Benbolt, and the zone of Hesperorthis australis
indicates the Wardell part. In some instances in the descriptive part of this
monograph it is stated that the fossils come from Benbolt (or Wardell) although
they are actually in the Dryden formation. The parts are so clear in these in-
stances that it is thought better to keep the added refinement. In other instances
the species are said to be from the Benbolt (or Wardell) part of the Dryden
formation.

In the vicinity of Lone Mountain, near Tazewell, Tenn., some mingling of
Benbolt and Wardell types can be detected. Here Doleroides appears low in the
section in such a position that it might be interpreted as belonging to the Benbolt
part of the Dryden formation. The listed fossils show the Benbolt-Wardell
relationships.

Chaulistomella brevis (Willard) Opikina speciosa Cooper

Dinorthis transversoides Cooper O. varia Cooper

Doleroides irregularis Cooper Petrocrania sp. 1

D. regularis Cooper Protozyga rotunda Cooper

Fascifera stonensis (Safford) Rostricellula ovata Cooper

F. subcarinata Ulrich and Cooper R. rostrata Ulrich and Cooper
Glyptambonites platys (Butts) R. tumidula Cooper

Hesperorthis australis Cooper Sowerbyella compacta Cooper
Mimella globosa (Willard) Strophomena grandimusculosa Cooper
Murinella muralis Cooper S. inspeciosa Willard

Oligorhynchia sp. 1 S. medialis Butts

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 59

Edinburg formation.—This name was proposed by Cooper and Cooper
(1946, p. 78) for the Chambersburg limestone of Virginia minus the Oranda.
The type section was taken near the Shenandoah River, 1.5 miles N. 61° E. of
Edinburg, Shenandoah County, Va. The lithology of the formation is so variable
that two facies and one member have been defined to make it better understood.
The Liberty Hall facies of the Edinburg formation consists of black, slabby con-
choidally-fracturing limestone that weathers to an ash gray. This facies was
called Athens by Butts (1940b, p. 159) and was thought by him to pinch out
under the “Chambersburg” (Butts, 1940b, p. 196) in the vicinity of Edinburg.
Cooper and Cooper, on the other hand, contend that the Virginia “Athens” is a
black limestone facies, including some black shale with graptolites, which inter-
fingers with the Lantz Mills facies of the Edinburg. This member consists of
cobbly limestone that comes to occupy more and more of the sequence in the
northern part of the range of the formation.

At the base of the formation is a granular, often brown-weathering and impure
limestone containing fossils that constitute a very distinctive assemblage. This
is the Botetourt formation, which is definitely related to part of the Arline, Effna,
and Pratt Ferry formations. It is thus now excluded from the Edinburg forma-
tion and combined with the Cybeloides bed under it.

Under the probable Boteourt formation at Edinburg dam and along Tumbling
Run 14 miles southwest of Strasburg, Va., where a superb section is exposed,
dark slabby limestones appear between the Lincolnshire and the Botetourt. These
limestones were placed by Butts (1949b, p. 197) in the Chambersburg, but were
left in the Lincolnshire by Cooper and Cooper. Faunally they are most like the
overlying Botetourt and are better placed with it. They are called the Cybeloides
beds after a trilobite which is fairly common in this limestone.

Cooper and Cooper (1946, pp. 81, 94, 95) note a number of sections in which
the sequence is well divided between the two facies. In the northern range of
the formation where the Lantz Mills facies is dominant it is possible to distin-
guish some elements described by Craig in Maryland and southern Pennsy]l-
vania. Craig’s Shippensburg formation is mainly composed of Lantz Mills facies
rocks. The upper massive beds with Camarocladia in the Strasburg section
undoubtedly belong to Craig’s Mercersburg formation.

Fossils are numerous in the Edinburg formation, and three major zones can
be readily recognized: The first is the Cyrtonotella zone, which also abounds in
Echinosphaerites as well as the zone-naming brachiopod ; the next zone is char-
acterized by the peculiar Nidulites pyriformis; and the third zone is that of the
massive limestones with Camarocladia. Brachiopods occur in all the zones; those
of the Cyrtonotella zone indicate the faunas of the combined interval of Effna,
Ward Cove through Benbolt, in terms of the Tazewell County sequence. Fos-
sils taken from the Nidulites zone are most suggestive of an early Trenton (Rock-
land) level although many genera from the lower beds pass upward through the
Edinburg, Oranda, and into the overlying Martinsburg (=Salona). No good
brachiopods have been taken from the Camarocladia beds.

60 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Edinburg formation (Echinosphaerites-Cyrtonotella zone)

Bilobia virginiensis Cooper Opikina bellula Cooper

Bimuria parvula Cooper O. dorsatiformis Cooper
Christiania platys Cooper Opikina sp. 3

C. subquadrata (Hall) Orthambonites bielsteini Cooper
Cristiferina cristata Cooper Oxoplecia multicostellata Cooper
Cyphomena angulata Cooper Palaeoglossa sp. 1

Cyrtonotella subplana Cooper Paucicrura matutina Cooper
Dactylogonia strasburgensis Cooper Perimecocoelia semicostata Cooper
Dinorthis transversa Willard Plectocamara magna Cooper
Eoplectodonta ? dubia Cooper Ptychoglyptus virginiensis Willard
Laticrura pionodema Cooper Scaphorthis kayi Cooper

Leptaena ordovicica Cooper Sowerbyella aequicostellata Cooper
Leptellina sp. 1 Trematis sp. 3

Limbimurina brevilimbata Cooper

Edinburg formation (Nidulites zone)

Christiania platys Cooper O. dorsatiformis Cooper

C. subquadrata (Hall) Paucicrura virginica Cooper
Cyphomena angulata Cooper Paurorthis spinosa Cooper
Dinorthis transversa Willard Plectocamara transversa Cooper
Hesperorthis sp. 2 Skenidioides obtusus Cooper
Lingulasma sp. 3 Sowerbyella aequicostellata Cooper

Opikina alata Cooper

Effna formation.—This name was proposed by B. N. Cooper (1944, p. 59)
for calcarenites overlying the Lincolnshire limestone and underlying the “Whites-
burg” limestone. The type section is in and near the McNutt Quarry located
about 12 miles southwest of Bland (14 miles southeast of Sharon Springs), Va.
The formation is generally composed of calcarenite or shell debris or both. At
the type locality it attains a thickness of about 221 feet, but it is thinner to the
southwest along the same belt and also in the northern belt. One of the best places
for the study of this formation is at the Porterfield Quarry, 5 miles east of Salt-
ville. At this place the Effna formed a great reef (now quarried away) at the
base of the Rich Valley formation. The McNutt Quarry locality is also a reef,
and it is likely that others appear along that line of outcrop. In Catawba Valley
Effna banks of calcarenite appear at the same level and in places interfinger
with the Botetourt formation as well as overlie it.

The fauna of the Effna is essentially that of the Arline formation of Tennessee.
At the Porterfield Quarry the Effna rests on a thin tongue of the Arline forma-
tion. It is evident, then, that the Effna is of the same age as part of the Arline
formation. It is therefore also evident that the Effna formation is older than the
Red Knobs formation which contains a thick calcarenite that overlies the Arline
in the Friendsville area.

Brachiopods are abundant in the reefy limestone as follows:

Bimuria superba Ulrich and Cooper C. plana Cooper
Camerella minuta Cooper C. triangulata Cooper
Christiania subquadrata (Hall) Cyrtonotella grandistriata (Willard)

Conotreta cuspidata Cooper Dactylogonia sp. 5

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 61

Doleroides ? ponderosus Cooper
Eridorthis inexpectata Cooper
Glyptambonites glyptus Cooper
Glyptoglossa sp. I

Glyptomena parvula Cooper
Glyptorthis glypta Cooper
Laticrura pionodema Cooper
Leptellina pulchra Cooper

L. tennesseensis Ulrich and Cooper
Lingulella lirata Cooper

L. subparallela Cooper

Lingulella sp. 4

Obolus ? virginiensis (Willard)
Obolus sp. 5

Oxoplecia abnormis Cooper

O. depressa Cooper

O. gibbosa Cooper

O. holstonensis Willard
Pachyglossa pachydermata Cooper
Perimecocoelia semicostata Cooper

P. triangulata Cooper

Petrocrania ? magna Cooper
Phragmorthis buttsi Cooper
Pionomena ? dubia Cooper
Productorthis agilera (Raymond)
Protozyga tumida Cooper
Pseudobolus sp. I

Ptychoglyptus virginiensis Willard
Piychopleurella medicostata Cooper
P. rectangulata Cooper
Scaphorthis perplexa Cooper
Schizambon cuneatum Willard
Schizotreta pannea (Willard)

S. shulert (Willard)

Skemdioides transversus Cooper
Sowerbyella negritus (Willard)
Spondylotreta ? declivis (Willard)
Taphrorthis peculiaris Cooper
Titanambonites crassus Cooper

Correlation of Effna formation.—A glance over the faunal list will show that
the Effna formation is related to the Arline formation of Tennessee and southern
Virginia, the Little Oak formation of Alabama, the Botetourt formation (or
member) of central and northern Virginia, and the Cyrtonotella zone of the
Edinburg formation. A few species such as Bimuria superba occur in the Arline
and the Effna. Ptychoglyptus appears to be confined to this suite of formations.
In Catawba Valley not only the fauna relates the Effna to the Botetourt but the
fact that the two interfinger indicates a close relationship between them. In the
Porterfield Quarry the Effna limestone is underlain by a thin, dark, siliceous
limestone that appears to be a tongue of the Arline formation.

Eggleston formation.—This name is applied to the dark-gray calcareous
mudrocks overlying the Moccasin formation and underlying the Martinsburg
formation (Curdsville). Parts of the limestone, particularly those associated
with metabentonites, are characterized by cuneiform jointing. Two thick meta-
bentonites appear in the upper part of the section and can be seen in many places.
This formation appears in the western belts of southwestern Virginia and East
Tennessee on the northwest slope of Wallen Ridge from Tennessee nearly to
Big Stone Gap, and throughout Russell and Giles Counties, Va.

The following brachiopods have been reported:

Dalmanella rogata (Sardeson) = Paucicrura rogata (Sardeson)
Pholidops sp. = Craniops sp.
Rafinesquina alternata (Conrad) = Rafinesquina trentonensis (Conrad)
*R. minnesotensis (N. H. Winchell) = Opikina minnesotensis (N. H. Winchell)

*Strophomena incurvata (Shepard)
Zygospira recurvirostris (Hall)

Eidson member of Lincolnshire formation—This name (B. N. Cooper
and G. A. Cooper) is used for the thinned portion of the Lincolnshire formation
underlying the Hogskin shale in the belts where that is present: Clinch Valley,

62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Hogskin Valley, and Beaver Valley. The rock is dark limestone containing
black chert. The type section is just north of Eidson, Kyles Ford (T.V.A.
170-SE) Quadrangle. Brachiopods are:

Dinorthis atavoides Willard

Macrocoelia duplistriata Willard
Sowerbyites triseptatus (Willard)

Ellett formation (B. N. Cooper and G. A. Cooper).—This name is proposed
for dark-gray limestones between the top of the Knox (Lower Ordovician) and
the Botetourt in the belt east of Roanoke Valley. The formation contains equiva-
lents of the Lenoir, Whistle Creek, and probably Lincolnshire. Silicified fossils
are abundant at Ellett and in Catawba Valley. The type section is in the fields
west of County Road 615, about 800 feet north of the Virginian Ry., near Ellett
Station, Blacksburg (15’) Quadrangle, Montgomery County, Va.

Camerella sp. Opikina sp. 5

Hesperorthis longirostris Cooper Rostricellula multicostata Cooper
Mimella gilberti Cooper Stenocamara perplexa Cooper
Multicostella quadrata Cooper Valcourea austrina Cooper

Elway formation.—B. N. Cooper (1945b, p. 42) proposed this name for
part of Butts’ Blackford formation which yields a blocky chert when weathered.
The rock is usually a fine-grained, light-gray limestone interbedded with layers
of dark-gray to black chert. In places, near Gate City, Va., and in Clinch Val-
ley, the limestone is often a gray calcarenite abounding in large ostracodes. The
formation varies from 30 to slightly more than 70 feet in thickness. It is wide-
spread in western belts of southwestern Virginia and Tennessee. The name is
taken from Elway on U. S. Highway 19 near Lebanon, Russell County, Va., and
the type section is near Blackford, Russell County. A few species of brachiopods
are common:

Camerella costellata Cooper Mimella intermedia Cooper

C. indefinita Cooper Mimella sp. 1

C. multiplicata Cooper Pionomena neumam Cooper

C. perplexa Cooper Protozyga microscopica Cooper
Dinorthis holdeni (Willard) Rhipidomena subparallela Cooper

Lingulella decorticata Cooper

Correlation of Elway formation.—This formation, by the presence of Rhipido-
mena, belongs in the suite with Lincolnshire and Whistle Creek. The Elway
may be a partial equivalent of the Whistle Creek because both formations con-
tain Dinorthis holdem.

Eyer member of Hatter formation.—Kay (1944, p. 7) proposed this name
for a gray, granular limestone, ranging from 6 to 37 feet in thickness, which lies
on the Clover member of the Loysburg formation and underlies the Grazier mem-
ber of the Hatter formation. The Eyer is restricted to south-central Pennsyl-
vania. The rock contains massive heads of Tetradium fibratum Safford. Kay
(1944, p. 12) lists the following brachiopods:

Campylorthis sp. = Chaulistomella sp.
Glyptorthis sp.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 63

Opikina sp.
Pionodema ? sp.

Rhynchocamara sp. cf. R. plicata Schuchert and Cooper = Camerella cf. C. plicata Schuchert
and Cooper
Strophomena sp.

Correlation of Eyer member.—The faunal list indicates correlation with the
suite of rocks from Benbolt up. Campylorthis, and Strophomena together with
a Camereila suggestive of C. plicata Schuchert and Cooper, indicate correlation
at about the level of the Wardell.

Fannettsburg member of Shippensburg formation.—This member (Craig,
1949, p. 722), at its type section 1 mile S. 70° W. of St. Thomas, Pa., consists
of 39 feet of light-gray crystalline limestone in heavy beds. The Fannettsburg
overlies the Pinesburg member of the Shippensburg formation in eastern belts.
It is conformably overlain by the Doylesburg formation. In western belts it is
overlain unconformably by the Mercersburg formation. In eastern belts the
member is fine-grained, dark gray, and slabby, but westward becomes more
coarsely granular, the two types of lithology intertonguing. The member is thick-
est, 263 feet, in the railroad cut southwest of Marion, but it thins rapidly to the
northeast and west to 7 feet in the former direction and 19 to 55 feet to the west.
Craig (1949, p. 726) correlates the member with the upper part of the Hostler
and the lower part of the Snyder. The Hostler member contains numerous
Solenopora, a feature also characteristic of the Fannettsburg. Cryptophragmus
occurs in the upper part of the Fannettsburg and forms the basis for the corre-
lation with the Snyder.

Fossils are said to be common in the Fannettsburg, and the following brachio-
pods are recorded by Craig (1949, p. 724) :

Campylorthis sp. cf. C. magna Schuchert *Opikina sp. aff. O. ampla Wilson

and Cooper = Chaulistomella sp. *Opikina sp. aff. O. gloucesterensis Wilson

*Corineorthis sp. *Opikina sp. cf. wagneri (Okulitch)
Glyptorthis sp. *Oxoplecia simulatrix (Bassler)
*Hebertella sp. Resserella sp.

Hesperorthis tricenaria (Conrad) cf. Rostricellula plena (Hall)

Leptaena ? sp. Sowerbyella sp. aff. S. alternata Butts
Leptaena sp. cf. L. homostriata Butts Sowerbyella sp. cf. aequistriata (Willard)
Leptobolus sp. “Sowerbyella” sp. cf. “S.” pisum (Ruedemann)
Mimella sp. Strophomena sp.
*Multicostella sp. Zygospira recurvirostris (Hall)

Correlation of Fannettsburg member.—Its position between Pinesburg and
Doylesburg members of the Shippensburg formation indicates correlation with
Wardell, but Cryptophragmus and Zygospira indicate that it may have affinities
with the Witten formation.

Farragut formation.—This name was proposed by C. E. Prouty (1946, p.
1156) for the “Holston” of the Concord, Tenn., belt. Prouty believes the name
“Holston” to have no validity as a formation because Keith proposed the term
for marbles regardless of their stratigraphic position. The type section of the
Farragut limestone is 1.4 miles east of Lowes Ferry, 94 miles southwest of Knox-

64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ville. The rock is a calcarenite, generally gray in color but often pink or reddish.
This formation has been correlated with the Effna and Lincolnshire formations.
The latter correlation is certainly wrong because the Effna formation is the par-
tial equivalent of the Arline formation containing Christiania which overlies the
Lincolnshire as shown by the Edinburg-Lincolnshire relationship in northern
Virginia. Prouty (1946, p. 1157) speaks of the Athens formation being younger
than the Farragut. This, too, is an error because the type Athens is the time
equivalent of the Arline. Fossils are fairly common in the Farragut but are
difficult to identify. This is true of most of the calcarenite formations because
the fossils must be broken out of the rock and specific details of the ornamenta-
tion are lost. The known brachiopods are:

Dactylogonia palustris (Willard)

Leptellina cf. L. elegantula (Butts)

Multicostella whitesburgensis Butts = M. bursa (Raymond)

Multicostella sp.

Oxoplecia holstonensis Willard
Schizambon sp.

Correlation of Farragut formation.—This formation appears to be equivalent
to the Arline and thus a correlate of the Effna.

Fetzer tongue of Arline formation (B. N. Cooper and G. A. Cooper).—
This thin but persistent bed is recognized in southeastern belts of the Southern
Appalachian region from Wytheville, Va., to Georgia. In the type section
along U. S. Route 64 about 3 miles southwest of Benton Station, Benton
(T.V.A. 126-NW) Quadrangle, Polk County, Tenn. the tongue consists of 6
to 8 feet of nodular, crumbly limestone with thin granular interbeds. The divi-
sion is readily identified by its characteristic assemblage of fossils which includes
Trinodus elspethi, Bronteopsis gregaria, Nicholsonella, Christiania, Bimuria, T1-
tanambonites, Cyrtonotella, and other brachiopods of the Arline. The division
is generally more argillaceous than the underlying beds of the Lenoir limestone.
The Fetzer is virtually the same unit as the Botetourt limestone member of the
Edinburg formation of the Shenandoah Valley of Virginia. The Fetzer is not as
silty and hard as the Botetourt but rather partakes of the general lithology of
the Arline limestone, and is a thin tongue of that formation. The name is taken
from Fetzer Creek, not far from the type section of the Fetzer along Ocoee
River. Additional brachiopods are:

Leptellina tennesseensis Ulrich and Cooper

Palaeostrophomena superba Cooper
Titanambonites amplus (Raymond)

Five Oaks formation—This name was applied in southwestern Virginia
by Cooper and Prouty (1943, p. 863) to a dove-gray calcilutite overlying the
Blackford (Elway) formation and underlying the Lincolnshire formation. No
brachiopods have been taken from it. This is one of the several calcilutites mis-
taken for the Mosheim of Tennessee. The Five Oaks actually is higher in the
section than the true Mosheim, which is a part of the Lenoir formation. The
latter is a partial equivalent of the Blackford formation below the Five Oaks.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 65

Fleanor formation.—This name is proposed by B. N. Cooper and G. A.
Cooper for about 200 feet of maroon and red shale, thin gray limestones, silt-
stone, and calcarenite. The name is taken from the exposures on a farm lane
along Foster Branch near Fleanor Mill, 2 miles northeast of Heiskell, Powell
Station (T.V.A. 137-SE) Quadrangle, Tenn. The formation contains:

Rhipidomena mesleri Cooper Oligorhynchia subplana Cooper
Mimella costellata Cooper Plectocamara sp.

Correlation of Fleanor formation—The few fossils found in this formation
clearly indicate correlation with the Hogskin member of the Lincolnshire
formation.

Gratton formation.—This name was applied by Cooper and Prouty (1943,
p. 872) to a thick limestone occurring in Virginia between the Benbolt and
Wardell formations in the belts northwest of Clinch Mountain. In general, the
formation consists of a lower zone of straticulate calcilutite with mud-cracked
surfaces and edgewise conglomerate ranging from 15 to 30 feet in thickness.
The upper part of the formation averages about 60 feet of medium- to thick-
bedded dove-gray calcilutite. Gratton fossils are difficult to identify, but Tetra-
dium is abundant and Cryptophragmus is present. No brachiopods have been
reported from the formation. The Gratton is a partial equivalent of the Wardell.

Grazier member of Hatter formation.—This is dark, dense, heavy-bedded
limestone with wavy partings, reaching 35 feet in thickness. The member was
named by Kay (1944, p. 10), and its type section is at Union Furnace, Pa. In
south-central Pennsylvania the member rests on the Eyer limestone, but to the
northeast it overlies the Clover member of Loysburg formation. The thickness
of the member decreases to the southeast, and it is only 7 feet thick in northern
Path Valley. At Waterside, Pa., the base of the member is characterized by a
coquina layer composed of Pionodema. The following brachiopods were seen:

Glyptorthis sp. Pionodema sp.
Mimella sp. Pionomena neumani Cooper
Opikina sp. Strophomena sp.

Correlation of Grazier member.—The presence of Pionodema indicates a cor-
relation in the post-Benbolt suite.

Greencastle bed (Bassler, 1919, p. 143).—Craig (1949, p. 739) suggests
the abandonment of this name because the Greencastle in several sections is a
confusion of parts of the Kauffman member of the Mercersburg formation.
Furthermore, the section at Greencastle is poorly exposed and structural com-
plications may have caused the repetition of Echinosphaerites and Nidulites. The
formation probably belongs to the present Oranda formation.

Hardy Creek formation.—This name was proposed by Miller and Brosge
(1950) for even-bedded, tan, dense, fine-grained limestone with oval chert nod-
ules in a few beds. The thickness varies from 93 to 150 feet. The formation is
poorly fossiliferous. This formation underlies the Cane Creek limestone and

66 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

overlies the Ben Hur formation. The name is taken from Hardy Creek in the
Jonesville District, Va. Brachiopods present are:

Campylorthis sp. Strophomena sp.
Opikina sp. Zygospira recurvirostris (Hall)
Pionodema minuscula Willard

Hatter formation.—This name was proposed by Kay (1944, p. 6) for a suc-
cession of limestones overlying the Loysburg formation and underlying the Ben-
ner formation in central Pennsylvania. It varies in thickness from 60 to 500
feet. It consists of three members: Eyer, Grazier, and Hostler. The brachiopod
content is listed under the various members.

Heiskell shale-—Apparently the only appearance of this name in the litera-
ture is on a chart by E. O. Ulrich (1911, pl. 27) correlating the Ordovician
formations of the eastern half of the United States. On Ulrich’s chart, Heiskell
is in the Tennessee Basin of the Appalachian Valley and in a division of this
called the Pearisburg Trough. Heiskell shale is correlated with the Pearisburg
limestone proposed by Bassler in 1907. According to Wilmarth, the shale was
“Probably named for Heiskell, Knox Co., Tenn., in SE corner of Briceville
quad.” The Heiskell is indicated by Ulrich as overlying the Holston and under-
lying the Lowyville.

At Heiskell a long sequence is fairly well exposed. Just east of the school
grounds on the east side of the village Cryptophragmus occurs in abundance on
the west side of a small stream. This would have been interpreted by Ulrich
as Lowville limestone. Shaly beds are exposed at the four corners in the center
of the village. These shales contain fossils of the Benbolt formation. Beneath
them are limestones assigned to the Ward Cove formation, and beneath that
limestones and red beds equivalent to the Hogskin and here called Fleanor
formation. Thus the only rocks answering lithologically to the Heiskell are the
Benbolt shales. Inasmuch as the name Heiskell was never established by defi-
nition or designation of a type section it cannot replace the well-established and
validly proposed name of Benbolt.

Hermitage formation.—Butts identifies this formation in the Appalachians
at Birmingham, Ala. The new species Sowerbyella angulata Cooper occurs in it.

Hogskin member of Lincolnshire formation.—This name is proposed
here by B. N. Cooper and G. A. Cooper for yellow-weathering shale and cobbly
limestone, both of “Ottosee type” and usually confused with that formation,
lying between the Eidson member of the Lincolnshire formation and the Ward
Cove or Rockdell formations. The Hogskin has not been identified outside of
eastern Tennessee. Belts from the north side of Knoxville nearly to the Cum-
berland Front have this formation more or less well developed. One of the best
displays is along the road from Thorn Hill to Washburn, especially at Red Hill
about 4 miles west-southwest of Thorn Hill. It is also well displayed in the
next belt to the north, in the Evans Ferry section along U. S. Highway 25E,
north of Indian Creek in the southern part of the Howard Quarter Quadrangle.
In the Heiskell-Maynardville belt the formation has passed over mostly to red

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 67

beds, but thin tongues of limestone contain the characteristic fossils of the forma-
tion. These red beds are well displayed near Heiskell and at Rose Hill near
Maynardville. They also appear in the belt running through Clinton, Tenn.

The Hogskin member seems to be a time equivalent of the Lincolnshire which
it displaces to the south and west. The faunal content generically is like that of
the Lincolnshire, but some of the species are different.

In belts south of Knoxville some parts of the Sevier, as at Miser and south
of Athens, contain fossils similar to those of the Hogskin. The species, how-
ever, appear to be different, and that part of the Sevier is related to the Benbolt
rather than the Hogskin because the Sevier beds referred to overlie the Arline
Christiania beds. The latter are related to the Ward Cove which in turn over-
lies the Hogskin. It is evident, therefore, that these Sevier beds have nothing to
do with the Hogskin but merely simulate its facies and repeat its generic types.

Brachiopods are numerous in the Hogskin formation, as follows:

Atelelasma obscurum Cooper Murinella biconvexa Cooper
A, platys Cooper M. semireducta Cooper
Camerella bicostata Cooper M. speciosa Cooper

C. quadriplicata (Willard) Oligorhynchia angulata Cooper
Cyrtonotella bella (Schuchert and Cooper) O. subplana Cooper
Dactylogomia concentrica Cooper O. subplana gibbosa Cooper

D. magna Cooper Oxoplecia recta Cooper

D. parva Cooper Paurorthis magna Cooper
Dinorthis willardi Cooper Petrocrania cicatricula Willard
Dorytreta reversa Cooper Plectocamara costata Cooper
Glyptorthis sp. 2 Protozyga microscopia Cooper
Macrocoelia duplistriata (Willard) Rhipidomena mesleri Cooper
Mimella costellata Cooper R. tenuitesta (Willard)

M. similis Cooper Schizotreta sp. 1

M. tumida Cooper Sowerbyites triseptatus (Willard)

Multicostella semisulcata Cooper

Holston limestone.—This is another of the Appalachian names that has lost
its usefulness by application to a lithology that occurs in many formations of
different ages. The name was originally proposed not as a formation name but
as applied to marble beds in the Chickamauga limestone. The name was later
used as a stratigraphic term for marbles in Tennessee and Virginia that were
thought to occupy a particular horizon, i.e., just above the “Lenoir.” Recent
work in Tennessee is reviving the term to be applied to the marbles in each of
the belts in the vicinity of Knoxville. It has not yet been satisfactorily demon-
strated that the marbles of these belts are actually the same. Furthermore, Prouty
(1946, p. 1156) proposed the name Farragut for the marble in the Concord belt
and recommended that the use of Holston be discontinued.

It should be evident from the nature and origin of calcarenite beds that they
are likely to have only a local development and meaning. They are the product
usually of the concentration of animal debris and therefore may occur at any
level and have much the same lithology at each level. They may represent the
debris accumulated by the continued occupation of a site by a crinoid-cystid
plantation, It is probable that close study of all the marbles will reveal criteria

68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

whereby each may be separated, but the state of our paleontology and sedi-
mentary petrology has not yet reached this desired goal. The name “Holston”
in the literature has been applied to calcarenites demonstrably of Lenoir, Lin-
colnshire, “Athens,” Benbolt, and Wardell associations. The name “Murat,”
which was applied to Lincolnshire calcarenites, was early abandoned in favor of
Holston. Because of the uncertainty and inaccuracy of the present application
of Holston, the name should be dropped as a stratigraphic term.

Hostler member of Hatter formation.—This member consists of tan-
weathering silicious or argillaceous limestone with ripple-marked surfaces. The
thickness ranges from 35 to 69 feet. Kay (1944, p. 10) designated the type sec-
tion as Union Furnace where it overlies the Grazier member of the Hatter forma-
tion and underlies the Snyder member of the Benner formation. Hostler rock
is so impure that it is never quarried for commercial lime with the result that it
is often left as a “rib” or a hanging wall in many of the large quarries. Butts
confused this formation with his Lemont member and related it to the Ridley
formation because it contains Maclurites. Although this correlation with Ridley
is believed to be correct, Butts was actually thinking of the Ridley as Lenoir or
Chazy, which it is not.

The Hostler member contains the following brachiopods :

Ancistrorhyncha sp. = A. crassa Cooper

Ancistrorhyncha sp. aff. A. costata Cooper = A. costata Ulrich and Cooper
*Camarotoechia sp. cf. C. plena (Hall)
*Campylorthis deflecta (Conrad) = Chaulistomella
*C. magna (Schuchert and Cooper) = Chaulistomella

Doleroides sp.

Glyptorthis sp.

Fascifera subcarinata Ulrich and Cooper
*Leptaena ? sp.

Opikina sp. aff. inquassa (Sardeson)

Opikina sp. cf. O. magna (Butts)

Opikina sp. aff. O. minnesotensis (N. H. Winchell)
*Opikina sp. aff. O. septata Salmon

Pionodema minuscula Willard

Pionodema sp.

Rostricellula ovata Cooper

Sowerbyella sp.

Strophomena sp. aff. medialis Butts

Strophomena sp.

Strophomena sp.

Correlation of Hostler member—Kay (1944, p. 12) correlates the Hostler
member of the Hatter formation with the Benbolt formation of Virginia. This
correlation is believed to be incorrect because the formation contains no species
in common with the Benbolt. The characteristic Dinorthis transversa Willard
is not present, nor is the host of other species and genera having affinities with
the Arline suite. Actually the fauna of the Hostler has its ties with beds higher
than the Benbolt, specifically with the Wardell formation. Wardell ties appear
in the Ancistrorhyncha, not yet known in the Benbolt, Fascifera subcarinata,

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 69

abundant Opikina and Strophomena like S. medialis Butts. Besides having a
fauna like that of the Wardell formation, the Hostler member is lithologically
reminiscent of the Ridley, equivalent of the Wardell in the Central Basin of
Tennessee.

Housum member of Mercersburg formation.—This name was proposed
by Craig (1949, p. 732) for the basal member of the Mercersburg formation
exposed only in the eastern belts of central Pennsylvania. The type section is
in the railroad cut 24} miles southwest of Marion. The member consists of 67
feet of tan to medium-gray, fine-grained, argillaceous, slabby, cream- to bufi-
weathering limestone with an interval of dark-gray, thin, crinkly, gray-weather-
ing limestone near the top. The member thins to the northeast. It contains few
fossils, but the presence of Leptaena (?) sp. cf. L. charlottae Winchell and
Schuchert was regarded as so important that the member was transferred from
the Shippensburg, where it had originally been placed, to the Mercersburg. As
shown elsewhere in this monograph, this fossil is a long-ranging one and does
not have the significance for correlation given it by some stratigraphers. The
few brachiopods recorded from this member are:

*Leptaena sp. cf. L. charlottae Winchell and Schuchert
Lingula sp.
Lingulasma sp.
Opikina aff. O. ruedemanni Salmon

*Sowerbyella ci. S. punctostriata (Mather)

Hurricane Bridge formation.—This name was proposed by Miller and
Brosge (1950) for 288 to 368 feet of calcilutite with occasional thin beds of
buff shaly mudstone. Tetradium cellulosum is abundant in the lower 150 feet.
The name is taken from exposures along and near the road southeast of Hur-
ricane Bridge, Hubbard Springs (T.V.A. 170-NW) Quadrange, Va. Brachio-
pods are uncommon.

Ancistrorhyncha sp.

Strophomena sp.
Zygospira ? sp.

Correlation of Hurricane Bridge formation—This formation underlies the
Woodway formation of Miller which contains fossils of the Wardell and Witten
formations and overlies the Martin Creek limestone, a probable Ward Cove
equivalent. The Hurricane Bridge formation is thus in the position of the Ben-
bolt formation and part of the Wardell but has the calcilutite facies with abun-
dance of Tetradium.

Jacksonburg formation.—This formation in northwestern New Jersey and
adjacent Pennsylvania occurs in two physiographic provinces: The Appa-
lachian Valley, and an extension of the New England Upland. In the Appa-
lachian Valley the formation consists of 135 feet of high-grade limestone resting
unconformably on the Kittatinny limestone. At the type section the lower 58
feet are faunally different from the upper 77 feet, and the lower Division is sepa-
rated from the upper by a conglomerate and a faunal change. The lower part

7O SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

contains Leperditia in abundance and was originally assigned to the Black River.
Elsewhere the Jacksonburg (R. L. Miller, 1937) attains a thickness up to 300
feet and is transitional to the overlying Martinsburg formation.

The lower division of the Jacksonburg contains Receptaculites occidentalis
Salter as well as Leperditia. Brachiopods found in the Lower Jacksonburg are:

Camarella inornata Weller = Idiospira inornata (Weller)

Dalmanella subaequata (Conrad) = Pionodema subaequata (Conrad)
Lingula sp. = Skenidioides sp.

Rafinesquina alternata (Emmons) = R. trentonensis (Conrad)
Scenidium anthonensis Sardeson = Skenidioides sp.

Strophomena conradi Hall and Clarke

Strophomena sp.

This list suggests assignment to lower Trenton rocks such as the Guttenberg
member of the Decorah because of the presence of Rafinesquina and Pionodema.
Correlation with the Nealmont of Pennsylvania, the Collierstown formation of
Virginia, and the Rockland of New York and Ontario is also possible.

Brachiopods from the upper division are:

Dalmanella subaequata (Conrad) = Pionodema subaequata (Conrad)
*D. testudinaria (Dalman) = Paucicrura sp. 2
Dinorthis pectinella (Emmons)
Lingula riciniformis Hall
Orbiculoidea lamellosa (Hall)
Orthis tricenaria Conrad
Parastrophina hemiplicata (Hall)
*Platystrophia biforata (Schlotheim) = Oxoplecia ?
*Plectambonites sericeus (Sowerby)
Plectorthis plicatella (Hall)
*P. (Austinella) whitfieldi (N. H. Winchell)
Rafinesquina alternata (Emmons)
Reuschella americana Cooper
*Rhynchotrema dentata (Hall)
*R. inaequivalvis (Castelnau)
Schizocrania filosa (Hall)
Strophomena conradi Hall and Clarke
*Strophomena incurvata (Shepard)
Zygospira nicolleti (Winchell and Schuchert) = Protozyga nicolletti (Winchell and
Schuchert)
Z. recurvirostris (Hall)

Correlation of upper Jacksonburg formation.—This list is difficult to interpret
because of unlikely species listed, but presence of Reuschella and Parastrophina
are links to Oranda and Salona.

Kauffman member of Mercersburg formation.—This formation has its
type section in the railroad cut 24 miles southwest of Marion, Pa. The mem-
ber consists of 168 feet of platy, bedded limestone lying conformably on the
Housum member of the Mercersburg formation and disconformably below the
Oranda formation. Craig (1949, p. 734), who named the member, states that it
thins to the northeast of the type section. In the western belts the member can
be recognized only in a few sections containing Mercersburg metabentonite No. 2.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER yA

The Kauffman is thought to correlate with the Centre Hall member of the
Nealmont formation. The following brachiopods were identified by Craig (1949,
pp. 736, 737) :

Dinorthis sp. cf. D. pectinella (Conrad)

Doleroides sp. cf. D. pervetus (Conrad)

Glyptorthis sp. cf. G. bellarugosa (Conrad)

Leptaena sp. cf. L. charlottae Winchell and Schuchert = Limbimurina

Lingula sp.

Sowerbyella sp. ci. S. punctostriata (Mather)

Strophomena 2 sp.

Zygospira recurvirostris (Hall)

Lantz Mills facies of Edinburg formation.—This name is applied by
Cooper and Cooper (1946, p. 78) to the cobbly to nodular, buff-weathering lime-
stone well developed near Lantz Mills about 4.6 miles N. 69° W. of Edinburg,
Va. As a facies this type of lithology appears at various levels in the Edinburg
formation. But on the west side of the Massanutten syncline and western belts
it is best developed in the lower part of the formation where it comprises the
Echinosphaerites-Cyrtonotella and Nidulites zones. On the east side of the Mas-
sanutten syncline this facies alternates with the black shale and limestone of the
Liberty Hall facies. The two fossil zones of the Edinburg formation mentioned
above roughly correspond to the Shippensburg formation of Craig (1949) and
are the Virginia equivalent of that formation.

Brachiopods taken from the Echinosphaerites-Cyrtonotella zone of the Edin-
burg formation are listed under this heading under the Edinburg formation.

Correlation of lower Lantz Mills facies—The correlation of this part of the
Lantz Mills facies of the Edinburg formation is with the interval from the Effna-
Arline to the lower part of the Benbolt. Effna-Arline affinities appear in the
presence of Ptychoglyptus, Christiama, Scaphorthis, Glyptambonites, and Cyrto-
notella. Dinorthis transversa is a link to the Benbolt.

Brachiopods from the Nidulites zone are listed under that heading under Edin-
burg formation.

Correlation of upper Lantz Mills facies —This portion of the Edinburg under-
lies the St. Luke member which is correlated with the Witten and the Rockland
formation. The part of the Edinburg with Nidulites bridges a long time interval.
The fauna, too, is somewhat transitional in having the last remnants of the Ben-
bolt (Dinorthis transversa) near the base and elements of the Wardell suite such
as Strophomena in the upper part.

Lemont member of Carlim formation.—This member was named by Butts
(1918, p. 526) for limestone exposed in the railroad cut a short distance south
of Lemont. At this place a species of Maclurites is fairly common and was con-
fused by Butts with M. “magnus” Leseuer of the Chazy group. Butts thus re-
garded his Lemont as a part of the Chazy and identified his member elsewhere
in Pennsylvania where the rock was shaly and had M. “magnus.” The type sec-
tion of the Lemont is actually at the top of the limestone sequence now called
Nealmont (Kay, 1944, p. 97). Butts’ use of the name Lemont was generally

72 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

for a brownish, shaly rock left as a “rib” in quarrying operations to which Kay
(1944, p. 10) applied the name “Hostler member of the Hatter formation.”
Butts’ Lemont of the type section is thus part of the Nealmont, and his Lemont
outside the type section is generally Hostler.

Lenoir formation.—B. N. Cooper and G. A. Cooper here restrict the name
Lenoir to the sequence exhibited at the type locality on the east side of Lenoir
City. So restricted, the long sequence containing Christiania, originally referred
to the Lenoir by many geologists, is excluded. The Christiania beds are now
called Arline formation. At the type locality the Lenoir contains three zones in
ascending order: Rostricellula zone, Valcourea-Mimella zone, and Maclurites
zone. In the southeastern belts in Tennessee the Rostricellula zone is widespread
but is often difficult to find. In places, such as the belt along the base of the
Great Smoky Mountains, it occurs in sinks or small masses (the Douglas Lake
is an example). It is often a mass of calcarenite abounding in Rostricellula and
other fossils, as behind the Friends Church at Friendsville.

The biggest and best development of the Lenoir is at Friendsville where each
of the zones is well developed and fairly thick.

To the west of the Friendsville area in Tennessee, across the strike of the
various belts, the Lenoir changes its lithology and is ultimately cut out. In its
changed lithology, the Lenoir appears as a calcarenite well exhibited near Tum-
bez in Virginia with a basal conglomerate containing Rostricellula, and the mas-
sive limestones above it contain Valcourea and Mimella. Here it has been called
the Tumbez formation (B. N. Cooper, 1945b, p. 133). The Blackford forma-
tion of dolomites, red beds, and conglomerates is equivalent to Tumbez and
Lenoir. In the belt along the Cumberland Front the Lenoir is missing; the
Blackford facies (Dot formation) there is equivalent to the Hogskin member of
the Lincolnshire formation.

Brachiopods identified in the restricted Lenoir are:

Aitelelasma variabile Cooper Onychoplecia brevirostris Cooper
Camerella triangulata Cooper Ptychopleurella glypta Cooper
Dactylogonia alternata Cooper Rostricellula basalaris Cooper
Dorytreta ovata Cooper R. costata Cooper

Hesperorthis tenuicostata Cooper R. multicostata Cooper
Macrocoelia nuclea (Butts) R. varicosta Cooper

M. plebeia Cooper Titanambonites praecursor Cooper
Macrocoelia sp. 1 Valcourea obscura Cooper

Correlation of restricted Lenoir formation—The Lenoir formation as re-
stricted contains elements of the Crown Point and Valcour formations of the
New York sequence. The Hesperorthis is a link to the Valcour, as is Titanam-
bonites, which ties the Lenoir to the higher beds. Onychoplecia and Valcourea
are suggestive of the Crown Point formation. The Mimellas might relate the
Lenoir to either of the New York formations. Actually the Lenoir fauna may
be more like that of the Valcour than now realized because description of the
fossils of the St. Martin formation will make available Valcour species of Dacty-
logonia, Mimella, and other genera not now recorded from the Valcour but
definitely present.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 73

Liberty Hall facies of Edinburg formation.—This name was used by
Cooper and Cooper (1946, p. 78) for black graptolitic shale and black con-
choidally fracturing limestone which interfingers with the Lantz Mills facies of
cobbly limestone. The Liberty Hall facies is best developed on the east side of
the Massanutten syncline and in the vicinity of Lexington and Natural Bridge,
Va. This facies corresponds in the Lexington region to the Liberty Hall forma-
tion of H. D. Campbell (1905, p. 445), In general, the Liberty Hall facies dis-
appears to the northeast and is best developed to the southwest.

The following brachiopods have been taken from the Liberty Hall facies:

Acanthocrania spinosa Cooper Laticrura pionodema Cooper
Camerella leiorhynchoidea Cooper Leptobolus sp. 1

Chonetoidea virginica Cooper Leptobolus sp. 2

Conotreta multisinuata Cooper Lingulella lirata Cooper
Cyclospira quadrata Cooper Oxoplecia holstonensis Willard
Ectenoglossa nymphoidea Cooper Paucicrura virginica Cooper
Elliptoglossa ovalis Cooper Perimecocoelia semicostata Cooper
E, rotundata Cooper Petrocrania sp. 2

Eoplectodonta sp. 1 Phragmorthis buttsi Cooper
Glyptambonites glyptus Cooper Ptychoglyptus virginiensis Willard
Kullervo parva Cooper Skenidioides costatus Cooper

Correlation of Liberty Hall facies—The black limestone interfingers with
Lantz Mills facies. The faunal list, with its many Botetourt and Arline elements,
shows that the lower Liberty Hall, like lower Rich Valley, contains lenses or
fingers of limestone with Arline fossils. The Liberty Hall facies also fingers with
beds having Wardell affinities.

The Whitesburg formation of East Tennessee is the same type of facies as
the Liberty Hall but seems not to have as great a stratigraphic range as the
Liberty Hall. It seems to include Benbolt equivalents, but nothing higher was
definitely identified. It is interesting to note that the rocks on the east side of
the Massanutten syncline in northern Virginia are mostly of the Liberty Hall
facies. On Opequon Creek east of Winchester fingers of Martinsburg lithology
appear in the Liberty Hall. This suggests that eastward Martinsburg lithology
would replace Liberty Hall if unmetamorphosed sequences were preserved. Such
fingers also appear in the Edinburg.

Lincolnshire formation.—This formation was named by Cooper and Prouty
(1943, p. 863) for exposures in the quarry on Lincolnshire Branch west of Five
Oaks, Va. It consists of dark, granular, cherty limestone ranging in thickness
from 40 to 100 feet. The formation is widespread in Virginia and the western
belts of East Tennessee. It is not known in the belts south of the Saltville fault.
The formation generally overlies the Five Oaks formation or formations sub-
jacent to the Five Oaks. It is overlain by the Ward Cove formation or its equiva-
lents. In the Clinch Mountain and adjacent belts to the north, the Lincolnshire
appears to be displaced entirely or in part by the Hogskin member. In these
areas two members are recognized: Eidson cherty limestone and Hogskin shale.

The Lincolnshire is the “Lenoir” of northern Virginia as mapped and de-
scribed by Butts. The formation extends in a northeasterly direction nearly to the

74 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Virginia—West Virginia line. In this direction the formation may be partially
equivalent to the New Market formation of Maryland and West Virginia.
Brachiopods are abundant in the Lincolnshire formation :

Atelelasma decorticatum Cooper M. semtisulcata Cooper
Camerella elliptica Cooper Oligorhynchia subplana Cooper
Cyrtonotella minor Cooper Oxoplecia eidsonensis Cooper
Dactylogonia obtusa Cooper O. recta Cooper

D. prona (Willard) Paurorthis magna Cooper
Dinorthis atavoides Willard Pionomena newmani Cooper
Hesperorthis biconvexa Cooper Plectocamara aseptata Cooper

H. longirostra Cooper Protozyga rotundiformis Cooper
H. multicostata Cooper Rhipidomena tenuitesta (Willard)
Macrocoelia duplistriata Cooper Sowerbyella medioplicata Cooper
M. platys Cooper Sowerbyites gildersleevet Cooper
Mimella laticardinia Cooper S. subnasutus Cooper

M. tumida Cooper S. triseptatus (Willard)
Mimella sp. 3 Valcourea sp. 1

Multicostella gerontica Cooper Valcourea sp. 2

M. plicata Cooper

Correlation of Lincolnshire formation—The correlation of this formation has
caused considerable difficulty because it has obvious similarity to the New York
Chazy but also equally strong relationships with post-Chazy rocks. Kay (1948,
p. 1405) correlates the Lincolnshire with the Chazy (Valcour) of New York
on the “bases (sic) of stratigraphic position, the presence of the overlying re-
gional unconformity and fossils not known in younger beds.” The Lincolnshire
formation contains equally strong post-Chazy faunal elements in the form of
Dinorthis, Sowerbyites, Cyrtonotella, Oxoplecia, and Sowerbyella. Not one of
these genera has yet been cited from the Valcour fauna, the fossils of which are
very like those of the Crown Point formation rather than the higher Black River
types. The only strictly Chazy types in the Lincolnshire are Multicostella and
Valcourea. Kay does not record the fossils on which he relies and which may
not be brachiopods.

Prouty (1946, p. 1152) correlates the Lincolnshire with the high Lenoir
(Christiania beds), here assigned to the Arline formation. This correlation is
untenable because the Lincolnshire underlies the Effna, Botetourt, or basal Edin-
burg, all of which are equivalents of the Arline formation and contain Christiania.
No trace of the Lincolnshire (or Elway) formations has been found in the Salt-
ville fault block and the Friendsville region.

Little Oak formation.—The Little Oak formation of Alabama was named
by Butts (1926, p. 112) but has long been misunderstood and has never been
satisfactorily correlated. It consists of thick-bedded, dark, nodular limestone
with nodular chert. The maximum thickness is Cahaba Valley is 500 feet. In
the neighborhood of Ragland, St. Clair County, Ala., it contains two layers of
metabentonite. Near Siluria the thinned edge of the Little Oak rests on black
shale (Columbiana formation). To the north along Cahaba Valley, the Little
Oak thickens enormously and rests on the Lenoir formation. It is here sug-
gested that the relationships in Cahaba Valley are those of a replacement be-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 75

tween Little Oak limestone and the black Columbiana shale. At Pratt Ferry

only the Columbiana black shale is present, except for the upper 20 feet of the

“Lenoir,” which contains Little Oak fossils and the thin Pratt Ferry formation.
Brachiopods are abundant in the Little Oak formation:

Atelelasma sp. Opikina sp. 4

Bimuria buttsi Cooper Orthambonites buttsi (Schuchert and Cooper)
Christiama subquadrata (Hall) O. mostellerensis Cooper
Dactylogonia geniculata Ulrich and Cooper O. tennesseensis Cooper

D. obsoleta (Butts) Oxoplecia gibbosa Cooper
Eremotoechia alabainensis Cooper Paurorthis fasciculata Cooper
Glyptorthis concinnula Cooper Plectorthis australis Cooper
Glyptorthis sp. 3 Polytoechia ? oakensis Butts
Isophragma extensum Cooper Productorthis americana Cooper

I. sulcatum Cooper Skenidioides platys Cooper
Laticrura heteropleura Cooper Sowerbyella varicostellata Cooper
Leptellina delicatula (Butts) Taphrorthis emarginata Cooper

L. tennesseensis Ulrich and Cooper Titanambonites amplus (Raymond)
Lingulella sp. 3 T. convexus Cooper

Macrocoelia ornata Cooper Titanambonites sp. 1

Multicostella fasciculata (Butts) Valcourea ventro-carinata (Butts)
Murinella sp. 3 Zygospira ? matutina Cooper

Correlation of Little Oak formation——This fauna was originally thought to
be related to the Oranda fauna (=Upper Chambersburg), but later Ulrich
(1930, p. 59) revised his views and stated that the Little Oak fauna is unlike
any other Blount fauna except that of the Holston marble. According to Ulrich
the fauna has a general resemblance to that of the upper Lenoir and through
that fauna with the middle Chazy of the Champlain Valley. In his correlation
chart Ulrich (1930, p. 73) places the Little Oak on top of the Blount group
but under the Lowville.

The Little Oak fauna is actually almost identical generically with that of the
Arline formation which is the cobbly limestone equivalent of the Athens forma-
tion (=Columbiana) of Tennessee. The rare genus Eremotoechia is known
only from these two formations and the Pratt Ferry formation, which is also
a manifestation of the Little Oak (see below). The Little Oak, like the Arline,
is also correlated with the Stinchar-Balclatchie limestones of the Girvan district
of Scotland. The Little Oak is also correlated with the Effna formation and the
Lower Edinburg formation of Virginia. The Little Oak appears to be equivalent
to the graptolitic Columbiana shale which contains Nemagraptus.

It is important here to state the conditions involving the Little Oak formation
at Pratt Ferry. At this place Lenoir, with big Maclurites, is overlain by 20 feet
of massive limestone that weathers with a white crust. Christiania is abundant
in this limestone together with Titanambonites and Isophragma, all Arline-
Little Oak fossils. This bed must be separated from the Lenoir with which it
has been mapped. The Pratt Ferry formation overlies the Christiania bed and
is thus within the Little Oak. It is overlain by Columbiana shale with
Nemagraptus.

Long Savannah formation.—In belts northwest of the White Oak Moun-

76 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

tain fault in southern Tennessee, Georgia, and Alabama, the Lower Ordovician
(Canadian limestones and dolomites) are succeeded by red beds and buff earthy
limestone 50 to 175 feet thick, which resemble closely the Blackford red beds
of Virginia and Tennessee and parts of the Attalla formation of Alabama. The
basal layers of the Long Savannah formation contain detrital chert and some
minor quartz sand. There are indications that the formation possibly ranges as
high as Peery and Rob Camp formations. It is also possible that the base, al-
though lithologically identical with the basal Blackford beds, is considerably
higher in the column than the latter. No fossils have been taken from the forma-
tion. The type section is exposed along the Mahan Gap Road, but the name is
taken from Long Savannah Creek just northeast of Snow Hill, Snow Hill
(T.V.A. 212-NE) Quadrangle.

Loysburg formation.—As described by Kay (1944, pp. 1-6), this formation
in central Pennsylvania consists of two members: The “Tiger-striped” and the
Clover. The formation lies between the Lower Ordovician Bellefonte formation
and the Hatter formation. The “Tiger-striped” consists of buff-weathering dolo-
mite which penetrates and channels the Bellefonte limestone. In addition to this
lithology are limestones, laminated dolomites, and thin beds of ostracode-bearing
limestone. This part of the sequence has never been studied in detail, but it is
possible that the dolomites and interbedded limestones between the Clover and
Lower Ordovician are to be correlated with the Row Park formation. The Loys-
burg, like the Blackford of Virginia, may be of different age in different places.

The Clover member is a sublithographic limestone mentioned under that head-
ing above. No brachiopods have been reported from the Loysburg formation.

Mahan formation.—(B. N. Cooper and G. A. Cooper.) This name is pro-
posed for 200 feet of ribbon-banded to thick-bedded dove-gray calcilutite, the
lower half of which is characteristically studded with plates and nodules of black
chert. The upper part of the formation is even-bedded Tetradium-bearing cal-
cilutite with numerous shaly interbeds containing Pionodema and Ancistro-
rhyncha. The Lower beds contain species of Strophomena, like those in the
Ridley limestone of the Central Basin of Tennessee, and S. inspeciosa Willard.
The Mahan formation succeeds a body of red dolomitic mudstone and inter-
bedded buff earthy limestones, the Long Savannah formation. The top of the
Mahan is defined at the type locality by a Moccasin-type red mudstone—one of
several red intercalations in a thick succession of ribbon-banded Camarocladia-
bearing limestones. The type section is along Mahan Road, Snow Hill (T.V.A.
112-NE) Quadrangle, about 1,900 feet west-northwest of the intersection with
Tennessee Highway 60, Hamilton County, Tenn. The Mahan formation is be-
lieved to include mainly beds of Benbolt and Pierce-Ridley affinities, but possi-
bly Peery and Rob Camp formations of southwestern Virginia are represented
in the lower part. (See Benbolt and Pierce-Ridley formations for lists of fos-
sils.) The Tetradiwm-bearing beds of the Mahan are lithologically indistinguish-
able from Hurricane Bridge formation as developed at Hagan, Va., and Speed-
well, Tenn.

Marcem formation (B. N. Cooper and G. A. Cooper, new formation) .—

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER Fy.

Along the northwest base of Clinch Mountain west of Gate City the Lincolnshire
formation is underlain by a section with conglomerate at the base, succeeded by
light-gray to pink massive calcarenite containing worn colonies of Billingsaria.
Minor portions of shale, mudstone, and calcilutite may be present. Dinorthis
holdeni (Willard) occurs in the upper part. The formation ranges from 120 to
300 feet thick. The basal beds contain Rostricellula basalaris Cooper. The
formation is thus a calcarenite equivalent of the Elway and Tumbez. The forma-
tion name is from Marcem Quarry, 2 miles west of Gate City, Va.

Martin Creek formation.—Miller and Brosge (1950) proposed this name
for dark-gray and brown limestone smelling of oil, with chert nodules and tan
cryptocrystalline limestone with abundant chert nodules in the upper part. The
thickness is 40 to 180 feet. It is named for exposures at the mouth of Martin
Creek, Back Valley (T.V.A. 161-SE) Quadrangle, Virginia-Tennessee. The
following brachiopods were identified :

Camerella sp. Rhipidomena tenuitesta (Willard)
Multicostella cf. M. saffordi (Hall and Clarke) Schizambon sp.

The formation is uncertainly correlated with part of the Ward Cove formation.

Martinsburg formation.—This formation consists of a thick mass of silty
and arenaceous shale overlying the great body of Middle Ordovician limestones
in the Appalachian Valley. The base of the formation, as exhibited near Green
Mount Church, about 5 miles north of Harrisonburg, Va., contains some thin
beds of limestone and has the fauna of the Salona formation of Pennsylvania.
The higher Martinsburg formation contains Eden and Maysville fossils, but only
the basal portion is of concern in this monograph. In southwestern Virginia and
East Tennessee the base of the Martinsburg formation contains thin-bedded
limestones abounding in Dinorthis and a large Sowerbyella. This part of the
section is correlated with the Curdsville formation of Kentucky. Brachiopods
are abundant at the base of the formation in most areas.

Brachiopods taken from the lower Martinsburg (Salona) near Green Mount
Church, Broadway (15’) Quadrangle, Va.:

Colaptomena leptostrophoidea Cooper Parastrophina sp. 1

Cyclospira quadrata Cooper Paucicrura subplana Cooper
Cyphomena grandis Cooper Petrocrania trentonensis (Hall)
Dalmanella sculpta Cooper Phragmorthis crassa Cooper
Eoplectodonta alternata (Butts) Plectorthis ponderosa Cooper
Laticrura magna Cooper Skenidioides elongatus Cooper
Leptaena ordovicica Cooper Sowerbyella cava Cooper
Orthambonites bielsteint Cooper S. eximia Cooper

Oxoplecia globularis Cooper Strophomena bellilineata Cooper

Parastrophina hemiplicata (Hall)

Brachiopods from the lower Martinsburg (Curdsville) in southwestern Vir-
ginia and Tennessee:
Dalmanella rara Cooper

Dinorthis pectinella (Emmons)
Hesperorthis tricenaria (Conrad)

78 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Onniella fertilis (Ulrich)
Rafinesquina trentonensis (Conrad)
Rhynchotrema sp.

Sowerbyella curdsvillensis (Foerste)
Zygospira sp.

Brachiopods from Sinuites zone at base of Martinsburg in Pennsylvania listed

by Bassler (1919, p. 165) are:

Christiania lamellosa Bassler = Bimuria lamellosa (Bassler )

Dalmanella edsoni Bassler = Reuschella americana Cooper

D, testudinaria (Dalman) var. = D. sculpta Cooper

Leptaena tenuistriata Sowerby var. = L. ordovicica Cooper

Leptobolus ovalis Bassler = Elliptoglossa ovalis (Bassler)
*Lingula riciniformis Hall = ?

Strophomena sculpturata Bassler = S. ? sculpturata Bassler

Triplecia (Cliftonia) simulatrix Bassler = Oxoplecia simulatrix (Bassler)

Meadow marble.—This name is applied (C. H. Gordon, 1924, p. 39) to a
calcarenite lens located southwest of Friendsville, Tenn., which is near the base
of the Sevier formation. It contains numerous fossils, especially brachiopods,
but the specimens are difficult to identify accurately because of poor preserva-
tion. The genera present in the formation are listed below.

Cyrtonotella sp. Paurorthis sp.
Glyptorthis sp. Protozyga sp. 1
Oxoplecia sp. Sowerbyella sp.

Mercersburg formation.—This formation was proposed by Craig (1949,
p. 731) for “dark grey, fine-grained, thin crinkly- and thick evenly-bedded blue-
grey weathering limestones with an interval of tan to medium-grey, slabby, buff-
weathering limestone at the base.” The type section is the railroad cut 2 miles
southwest of Marion, Pa. The formation thins from 235 feet at the type section
to 155 feet at Middle Spring to the northeast, and to less than 100 feet in the
belts to the northwest. The formation is composed of the Housum and Kauff-
man members. The brachiopods reported by Craig are listed under the member
names,

Moccasin formation.—This name is applied to the red and yellow mudrock
overlying the Witten formation and underlying the Eggleston formation. This
rock is widespread in southwestern Virginia and East Tennessee. In the western
belts occasional fingers of calcilutite appear. In Sequatchie Valley, Tenn.,
equivalents of the Moccasin are referred to Lebanon and Carters limestones.

Pseudolingula luttrellensis Cooper
Zygospira lebanonensis Cooper

Mosheim formation (=facies).—This is really a facies rather than a
formation and has been widely misidentified as a formation. The name should
be used only for calcilutites associated with the restricted Lenoir formation in
the southeastern belts and their equivalents. At the type section, the formation
overlies the Knox dolomite but underlies Lenoir lithology. Northeast of Friends-
ville typical Mosheim appears, sandwiched between beds with typical Lenoir

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 79

lithology. Behind the Friends Church in Friendsville, Mosheim is also under-
lain by calcarenites abounding in typical Lenoir species. Thus the Mosheim is
a part of the Lenoir, but it is discontinuous and appears at different levels in the
Lenoir. This type of rock containing a fairly definite molluscan fauna can be
seen as far southwest as the Cahaba Valley of Alabama, and to the northeast it
is known in south-central Virginia, as at Marion where it overlies calcarenites
containing fossils, in both places like those behind the Friends Church. The
Mosheim fauna contains few brachiopods, but the few that have been found
are unusual types:

Rostricellula basalaris Cooper

Stenocamara bicostata Cooper
S. perplexa Cooper

Murat formation.—This is also a facies rather than a formation and is litho-
logically like the “Holston” of Tennessee. It is not, however, of the same age
as the Holston and is more usually a gray limestone, particularly in its type
region. The Murat is a calcarenite equivalent of the dark, cherty Lincolnshire
formation. Fingers of the Lincolnshire can be seen in the calcarenite near Lex-
ington, also in localities on the Pressmens Home Quadrangle, Tenn. Numer-
ous brachiopods have been taken from the formation but, like those of the so-
called Holston limestone and Meadow marble, are difficult to identify because of
poor preservation.

Atelelasma decorticatum Cooper Mimella laticardinia Cooper
Dactylogonia marmorata Cooper Pseudobolus gibbosus (Willard)
Dinorthis atavoides Willard Schizambon hirsutum Cooper
Glyptomena bella Cooper Sowerbyites triseptatus (Willard)

Nealmont formation.—The name was proposed by Kay (1944, p. 97) for a
sequence of limestones exposed in all the belts of central Pennsylvania. It con-
sists of three members from the base up: Oak Hall, Centre Hall, and Rodman.
The formation is composed of limestone and is correlated with the lower part of
the Trenton. The brachiopods are listed under the separate members except for
those listed below for which data relating them to the members are lacking:

Ancistrorhyncha australis (Foerste) Pionodema sulcata Cooper
Craniops trentonensis (Hall) Zygospira elongata Cooper

New Market formation.—This name was proposed by B. N. Cooper and
G. A. Cooper (1946, p. 71) for calcilutites overlying the Knox formation but
underling the Lincolnshire formation. The type section is in the Madden Quarry
0.65 miles west of New Market, Va. To the northeast of the type section the
New Market thickens and its stratigraphy becomes complex. Neuman (1951,
p. 286) amplified the New Market formation and identified the so-called “Low-
ville” underlying the Chambersburg formation (Shippensburg of Craig) as New
Market. Cooper and Cooper (1946, p. 69) identified the New Market forma-
tion underneath an 800-foot sequence of “Stones River” which immediately
underlies the “Lowville.””’ The New Market of Cooper and Cooper near Marion,
Pa., fingers at the base with dolomites, as it does at New Market.

80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Neuman named the 800-foot sequence of “Stones River” the Row Park
formation. Cooper and Cooper had previously identified this sequence as Whistle
Creek on the basis of contained fossils. Below the New Market of Cooper
and Cooper, Neuman discovered granular limestone containing abundance of
Rostricellula.

The seemingly conflicting identifications of New Market by Cooper and
Cooper and Neuman can be interpreted as a facies condition.

It is postulated here that both identifications of New Market are correct, but
that the Row Park is a partial facies of the New Market and also the Whistle
Creek. Neuman shows New Market lithology interfingering with Maclurites-
bearing limestones. The same situation can be seen at Wilson, Md., and in the
big quarry at Pinesburg, Md. Thus the New Market is sandwiched between
Rostricellula beds of the Row Park at the base and the main body of the Row
Park. It interfingers with the main mass of the Row Park. New Market also
overlies Row Park, as it does near Marion.

A more moot point is the suggestion by B. N. Cooper and G. A. Cooper
(1946, p. 70) that New Market (their “Lowville” facies) interfingers also with
the Lincolnshire which overlies New Market at its type section. The Lincoln-
shire thins to the northeast in the same direction in which the New Market
thickens. Lincolnshire is not certainly known in Maryland, but a tongue of dark
limestone on the New Market in a quarry at Wilson is tentatively indentified
as Lincolnshire.

The facies shifts described above are like those that occur elsewhere in the
Appalachians. In fact the whole of the Appalachian sequence treated herein,
except the Martinsburg, passes into calcilutites of one kind or another.

Few brachiopods have been taken from the New Market:

Pionomena neumant Cooper
Rostricellula elliptica Cooper

Oak Hall member of Nealmont formation.—This member was defined by
Kay (1944, p. 97) for exposures on Pennsylvania Highway 322, 1 mile west of
Tusseyville, Pa. The Oak Hall is the lowest member of the Nealmont formation
and consists of heavy-bedded limestone about 60 feet thick. The Oak Hall lies
unconformably over the Valentine formation. At Bellefonte, Pa., the Oak Hall is
absent from the Nealmont formation, except for channels in the underlying
limestone.

Ancistrorhyncha sp. = A. australis (Foerste)
Camarotoechia sp. = Rostricellula sp.
Leptaena (?) sp. cf. L. charlottae Winchell and Schuchert = Bellimurina

Leptaena sp.
Zygospira recurvirostris (Hall)

Ooltewah formation (B. N. Cooper and G. A. Cooper).—This formation,
named from Ooltewah, Hamilton County, Tenn., consists of 250 to 600 feet of
ribbon-banded Camarocladia-bearing limestone with numerous intercalations of
red Moccasin-type mudstone and fewer interbeds of buff shaly limestone over-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 81

lying the Long Savannah formation and overlain by the Bays formation. The
lower half of the formation contains thin, shaly layers packed with Ancistro-
rhyncha, Pionodema, and Sowerbyella. The upper beds contain abundant Dolo-
roides, Pionodema, Opikina, Hesperorthis, and Chaulistomella. The Ooltewah
limestone is linked with the Ridley and Lebanon limestones of the Central Basin
of Tennessee, with the Witten and Wardell formations of the middle belts of
southwestern Virginia, and with the Hardy Creek-Ben Hur-Witten and Upper
Dryden formations of Powell Valley, Lee County, Va. The type section is along
Mahan Gap Road and extends for a quarter of a mile or more on either side of
State Highway 60, Snow Hill (T.V.A. 112-NE) Quadrangle, Hamilton County,
Tenn. The following brachiopods in addition to those recorded above also occur:

Fascifera subcarinata Ulrich and Cooper Strophomena grandimusculosa Cooper
Rostricellula ovata Cooper S. inspeciosa Willard

Oranda formation.—This name was proposed by Cooper and Cooper (1946,
p. 86) for the upper 30 or more fect of the old Chambersburg formation which
is lithologically and faunally very distinctive. The name is taken from a hamlet
about 3.5 miles northeast of Strasburg, Va., and the type section is on Virginia
State Highway 55, about 0.4 mile west of its junction with U. S. Highway 11
in the north outskirts of Strasburg.

Lithologically the Oranda in many parts of Virginia is a calcareous, fine-
grained, dirty sandstone. Fossils are numerous and the matrix is ideal for dis-
solving the shells out of the rock to produce molds of great fidelity (see illustra-
tions of Eoplectodonta alternata and Strophomena bellilineata). The sandy
character of the formation makes it resistant and thus easily recognized through-
out its range. The formation has been identified in Maryland and southern Penn-
sylvania, but in the latter region it becomes somewhat shaly and contains thin
beds of dark limestone.

In the vicinity of Strasburg and along that belt for miles the Oranda main-
tains its arenaceous character. In the vicinity of Green Mount Church, how-
ever, about 4 to 5 miles north of Harrisonburg, Va., the formation contains
many thin layers of limestone and suggests a passage, in this direction, to a
more limy character.

The Oranda formation has elements of the Kimmswick limestone of Missouri,
the Salona of Pennsylvania, and parts of the Trenton of New York. In the
vicinity of Lexington and Natural Bridge, Va., the Oranda has not been identi-
fied, but its place in the section is occupied by the Collierstown formation which
is completely unlike the Oranda lithologically and faunally. It is interesting to
note that the dark shales under the Eureka quartzite in central Nevada contain
a fauna almost identical in generic composition to the Oranda formation of
Virginia.

Brachiopods of the Oranda formation:

Bilobia hemispherica Cooper Cristiferina cristifera Cooper
Bimuria lamellosa (Bassler) Cyphomena homostriata (Butts)
Chaulistomella sp. 2 Dalmanella costellata Cooper

Christiania auriculata Cooper Elliptoglossa ovalis (Bassler)

82 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Eoplectodonta alternata (Butts) O. multicostellatus Cooper

E. ? triradiata (Butts) Oxoplecia simulatrix (Bassler)
Furcitella plicata Cooper Parastrophina sp. 2
Glyptambonites musculosus Cooper Paterula perfecta Cooper
Hesperorthis virginiensis Cooper Ptychopleurella sulcata Cooper
Laticrura magna Cooper Rafinesquina planulata Cooper
Leptaena ordovicica Cooper Reuschella americana Cooper
Leptellina abbreviata Cooper Schizotreta microthyris Cooper
Lingulasma compactum Cooper Skenidioides rectangulatus Cooper
Lingulasma sp. 1 Sowerbyella cava Cooper
Nicolella strasburgensis (Butts) S. eximia Cooper

Orbiculoidea linnvillensis Cooper Strophomena bellilineata Cooper

Orthambonites bielsteini Cooper

Correlation of Oranda fauna.—Perhaps the most striking feature of this fauna
is its close similarity generically to the faunas of the Arline, Effna, Pratt Ferry,
and lower Edinburg formations. The relationship to the Stinchar-Balclatchie
formation of the Girvan district, Scotland, is also striking. It seems obvious
that the Oranda fauna is a recurrence of the Arline fauna but with modifications
that give it the stamp of the Trenton. These younger elements among the brachi-
opods are Strophomena, Rafinesquina, Dalmanella, Leptaena, Parastrophina, and
Furcitella. The latter is similar to F. schofieldi of the Prosser of the Mississippi
Valley.

Kay (1948, p. 1402) places the Oranda opposite the Shoreham member of
the Sherman Fall formation in his correlation table. The Oranda distinctly
underlies the zone of abundant Cryptolithus trilobites although this trilobite also
occurs in it. Cryptolithus, however, is a rare fossil in the Oranda. Reuschella
is another Sherman Fall guide fossil, but the Virginia representative of this genus
is clearly a different species from the Vermont R. edsoni. It is the writer’s belief
that the Oranda formation, by virtue of its position, is pre-Sherman Fall.

The Oranda formation is also closely related to the Prosser formation because
of the presence of Echinosphaerites and the brachiopod Furcitella. In the Appa-
lachians the Oranda is directly referable to the Rodman formation of Butts.

Ottosee formation (=facies).—This is a facies ranging in age from the
Hogskin member of the Lincolnshire formation through the Wardell formation.
As applied by some Appalachian workers the name has been used for any of the
yellow-weathering shales regardless of age. The name is also applied to cobbly
limestone in the western belts of Virginia and an assortment of other rocks. The
type section is at Chilhowee Park in Knoxville, and this part of the section is
probably equivalent to the Benbolt formation. The name is better dropped from
the Appalachians and is therefore not used in this monograph.

Paperville formation (B. N. Cooper and G. A. Cooper).—This unit com-
prises a thick succession of gray siltstones, black graptolitic shales and interbedded
black limestones, and brown-weathering calcareous sandstones which Keith
mapped as Athens in southeastern belts of the Appalachian Valley in Tennessee.
These beds form the lower division of a buff-weathering shale-siltstone-sand-
stone succession totaling several thousand feet in thickness, succeeding the thin

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 83

but persistent Fetzer formation. The name is taken from Paperville, near Bris-
tol, Bristol (T.V.A. 206-SW) Quadrangle, where the shales are well exposed.
The type section is along Steele Creek, near Paperville, and has been described
by Decker (1952, pp. 39-47), who collected representatives of many well-known
Normanskill graptolites from these beds. The Paperville shales are capped by
the ridge-making calcareous brown-weathering sandstones of the “Tellico”
formation. Few brachiopods are known:

Ectenoglossa nymphoidea Cooper
Obolus biconvexa Cooper

Peery formation.—This name was proposed by Cooper and Prouty (1943,
p. 863) for a sequence lying between the Ward Cove and Benbolt formations.
It consists of a lower cherty limestone, thin-bedded and dark gray, weathering
to ash gray. The upper part of the formation is a dove-gray calcilutite. The
lower part averages 30 feet thick, but the upper part is usually less than 50 feet
thick although it reaches 140 feet at one locality. The best development is north-
west of Clinch Mountain. The formation is also present on the southeast side
of Clinch Mountain but is usually less than 20 feet thick. On this side of Clinch
Mountain the Peery overlies Rich Valley limestone but underlies Benbolt shale.

In the Peery, on the northwest side of Clinch Mountain, fossils are com-
mon but poorly preserved in the lower part; they are uncommon and poorly
preserved in the upper part. B. N. Cooper reports, with additions of new forms,
the following brachiopods:

Ancistrorhyncha crassa Cooper

Mimella sp.

Multicostella sp.

Sowerbyella aequistriata (Willard)

S. delicatula Butts = ? Leptellina delicatula (Butts)
S. ci. S. negritus (Willard)

Sowerbyella sp.

Sowerbyites sp.

Strophomena fasciculata Cooper

S. “filitexta’ (Hall) = S. basilicoidea Cooper
S. tenuitesta Willard

Pelham limestone.—This is a broad name that is nearly equivalent to Chicka-
mauga limestone because it embraces the interval from the top of the Knox to
the Clinton. The name was long neglected while Chickamauga was becoming
entrenched in the literature. Actually neither name now has any value because
the Chickamauga sequence of Georgia and the Pelham of Alabama can be divided
into several formations ranging in age from Marmor to Trenton or higher.

Pinesburg member of Shippensburg formation.—This name was proposed
by Craig (1949, p. 718) for 140 feet of cobbly and slabby limestone. The type
section is on the south side of U. S. Highway 30, 1 mile S. 70° W. of St. Thomas,
Pa., although the name is taken from Pinesburg Station in Maryland. The
lower part of the member is of platy-weathering limestone, the middle part (73
feet at type section) of cobbly limestone, and the upper 36 feet of dark-gray platy

84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

or slabby limestone. In the eastern belts the member attains a thickness of 238
feet, but it thins to 21 feet near Spring Run; it thickens again to the west and
is 41 feet thick in Blacklog Valley. Echinosphaerites is abundant in the lower
part of the member and Nidulites in the upper part. Brachiopods are numerous:

Bilobia virginiensis Cooper
Bimuria parvula Cooper
*Camerella sp. cf. C. varians Billings
Cyphomena angulata Cooper
Dinorthis transversa Willard
*Doleroides (?) sp.
Glyptoglossa cavellosa Cooper
Glyptorthis sp. cf. G. bellarugosa (Conrad) = G. equiconvexa Cooper
*Hesperorthis sp. cf. H. tricenaria (Conrad)
Leptaena sp. = L. ordovicica Cooper
*Leptellina (?) sp. cf. L. elegantula Butts
Lingula sp.
Lingula sp. 10
Lingulasma sp. 2
Mimella sp.
*Multicostella sp.
Opikina bellula Cooper
*Opikina sp. cf. O. ruedemanni Salmon
Opikina sp. cf. O. wagneri (Okulitch)
Orthambonites bielstein Cooper
O. rectangulatus Cooper
Oxoplecia aff. O. calhouni Wilson = O. magnaplicata Cooper
*O. simulatrix (Bassler)
*Parastrophina sp. cf. rotundiformis (Willard)
Paurorthis ponderosa Cooper
Plectocamara magna Cooper
Plectorthis sp. 1
Protozyga sp.
Pseudolingula sp. 1
Resserella sp. = Paucicrura matutina Cooper
Scaphorthis kayi Cooper
*Skenidium (?) sp. cf. S. anthonense (Sardeson) = Skenidioides obtusus Cooper
S. aequicostellata Cooper
*Sowerbyella sp. cf. S. aequistriata (Willard) = S. aequicostellata Cooper
Sowerbyella sp. cf. S. alternata Butts = Eoplectodonta ? dubia Cooper
“Sowerbyella” sp. cf. “S.” piswum (Ruedemann) = Bilobia virginiensis Cooper
Strophomena sp.
Strophomena sp. 1
Strophomena sp. 2

Correlation of Pinesburg member.—The lower part of the Pinesburg member
is its most fossiliferous part. This contains the Echinosphaerites zone and numer-
ous representatives of the Cyrtonotella zone of the Edinburg formation of Vir-
ginia. The upper boundary of the Pinesburg member has not yet been identified
in Virginia.

Poteet formation.—Miller and Brosge (1950) proposed this name for 45 to
97 feet of gray-brown and tan, fine-grained, heavy-bedded limestone named from

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 85

exposures along the lane north of Poteet Ford, Ben Hur (T.V.A. 170-NE)
Quadrangle, Va.-Tenn. A zone of calcarenite 7 to 8 feet thick (Yellow Branch
member) occurs near the base. The zone is well exposed on the road along Yel-
low Creek on the south-central margin of the Rose Hill (T.V.A. 161-NE) Quad-
rangle. Brachiopods are mostly from the calcarenite near the base and are listed
under the heading of Yellow Branch member of the Poteet formation.

Correlation of Poteet formation.—This formation underlies the Rob Camp for-
mation and overlies the Dot formation. The latter belongs to the Blackford facies
here, a probable partial equivalent of the Lincolnshire formation. The Poteet is
thus probably related to the Ward Cove formation.

Pratt Ferry formation.—This name is here proposed (B. N. Cooper and
G. A. Cooper) for the limestone at the base of the black Columbiana shale 0.2
mile southeast of Pratt Ferry. Widening and paving of the road at this locality
has resulted in a fine exposure. The rock is also well exposed in the woods on
the east side of the road. About 8 feet of somewhat bituminous calcarenite are
exposed in layers varying in thickness up to 4 inches or more. This is the only
exposure of the formation known in Alabama. It overlies heavy-bedded gray
limestone mapped as Lenoir limestone but which contains the Christiania fauna
of the Little Oak (see Little Oak). The Pratt Ferry is overlain by black shale
with Nemagraptus and other graptolites of that zone.

The formation abounds in fossils. Trilobites are numerous, particularly Tele-
phus, Trinodus, and ceraurids. Brachiopods are abundant and include a variety
of inarticulate genera as well as a rich representation of articulates. Treatment
with acetic acid yields a harvest from this limestone. Many bizarre and unusual
genera are now known from this formation:

Acanthambonia minutissima Cooper Kullervo sulcata Cooper
Anisopleurella tricostellata Cooper Leptellina pulchra Cooper
Bellimurina sulcata Cooper Lingulella alabamensis Cooper
Bimuria siphonata Cooper L. lirata Cooper

Christiania subquadrata (Hall) L. pachyderma Cooper

Conotreta apicalis Cooper Lingulella sp. 8

C. concentrica Cooper Nothorthis tarda Cooper

C. depressa Cooper N. transversa Cooper

C. gigantea Cooper Obolus sp. 3

C. multisinuata Cooper Obolus sp. 4

Craspedelia marginata Cooper Orthambonites tenuicostatus Cooper
Cyclomyonia peculiaris Cooper Pachyglossa dorsiconvexa Cooper
Dictyonites perforata Cooper P. pachydermata Cooper
Diorthelasma parvum Cooper Parallelelasma pentagonum Cooper
Elasmothyris concinnula Cooper Parastrophina bilobata Cooper
Elliptoglossa ovalis Cooper Paterula perfecta Cooper
Eoconulus rectangulus Cooper Perimecocoelia semicostata Cooper
Ephippelasma minutum Cooper Phragmorthis buttsi Cooper
Eremotoechia silicica Cooper Ptychoglyptus virginiensis Willard
Glossella papillosa Cooper Rhysotreta corrugata Cooper
Glyptambonites glyptus Cooper Scaphelasma septatum Cooper
Glyptorthis glypta Cooper Schizambon sp. 2

Isophragma sp. 1 Schizotreta corrugata Cooper

86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

S. subconica Cooper T. minor Cooper

S. willardi Cooper Trematis elliptopora Cooper
Skenidioides convexus Cooper T. ? spinosa Cooper
Spinilingula intralamellata Cooper Triplesia carinata Cooper
Spondylotreta concentrica Cooper Tropidothyris pentagona Cooper
Taphrorthis peculiaris Cooper Undiferina rugosa Cooper
Titanambonites amplus (Raymond) Westonia superba Cooper
Torynelasma toryniferum Cooper Xenambonites undosus Cooper

Correlation of Pratt Ferry formation.—The fauna of the Pratt Ferry forma-
tion is obviously closely related to that of the Arline formation and its correla-
tives. The position of the formation is most interesting because it really is a
part of the Little Oak formation. Cambrian elements, such as Lingulella, and
Dictyonites which is a member of the family Micromitridae, form another inter-
esting feature of the fauna.

Red Knobs formation (B. N. Cooper and G. A. Cooper).—The Red Knobs
formation is a thick succession of red to pink calcarenites and limy ferruginous
sandstones up to 750 feet in thickness. The exposures from which the name
is taken are near and along the Blount-Loudon County line, near Meadow, on
the Meadow (T.V.A. 139-NW) Quadrangle. The lower part of the Red Knobs
formation consists of red to pink marble—the Holston marble of Ulrich, Gordon,
Rodgers, and others, which is well exposed in the old marble quarries just south-
east of Friendsville, Louisville (T.V.A. 138-SE) Quadrangle. The upper beds,
which yield a characteristically dark-maroon, sandy regolith, are calcareous sand-
stones and ferruginous sandy calcarenites with partings of greenish-gray to buff
shale. The marble beds contain Multicostella, Atelelasma, Oxoplecia holstonen-
sis, and numerous bumastid trilobites.

Dinorthis venusta Cooper O. holstonensis Willard
Obolus ? grandis Cooper O. marmorata Cooper

O. ? virginiensis (Willard) Philhedra ferruginea Cooper
Oligorhynchia inex pectata Cooper Skenidioides costatus Cooper
Oxoplecia gibbosa Cooper Valcourea sp. 3

Correlation of Red Knobs formation.—By position and faunal character this
formation is correlated with the Benbolt. It occurs above the Arline. Its assem-
blage of species seems to be from the Arline.

Rich Valley formation (B. N. Cooper and G. A. Cooper).—This forma-
tion consists of black and chocolate-brown shales, containing abundant grapto-
lites, brachiopods, and trilobites, which range in thickness from a few feet to
350 feet. The type section is immediately south of the Porterfield Quarry and
Worthy Mine of the Mathieson Chemical Corp., about 7 miles east-southeast of
Saltville on the Maccrady (T.V.A. 218-NW) Quadrangle, Smyth County, Va.
The basal 40 feet of black shaly limestone which capped the limestone reef in
Porterfield quarry (G. A. Cooper, 1940, pp. 17-20) constitutes the lower part of
the Rich Valley formation. These beds have yielded some of the most remark-
able fossils found in the Appalachian Valley, and most of the species listed below
are from this part of the Rich Valley. At Quarry Village, south of Saltville on
the Glade Spring (T.V.A. 212-SE) Quadrangle, the base of the Rich Valley

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 87

formation is black shale containing a profusion of Normanskill graptolites and
the trilobites Telephus bicornis, Robergia major, Porterfieldia caecigenus, Ampyx
americanus, A. camurus, and Bevanopsis. The beds herein defined as the Rich
Valley shale are the lower and characteristic part of a unit widely identified by
Butts, Decker, and others as Athens shale. The Rich Valley corresponds to the
lower part of the Liberty Hall black-limestone-black-shale succession of central-
western Virginia.

Bimuria immatura Cooper O. parvicrassicostatus Cooper
Glyptambonites glyptus Cooper Phragmorthis buttsi Cooper
Glyptomena parvula Cooper Ptychopleurella mediocostata Cooper
Glyptorthis glypta Cooper P. rectangulata Cooper

Kullervo ornata Cooper Scaphorthis perplexa Cooper

K. parva Cooper Scaphorthis sp. 1

Laticrura pionodema Cooper Schizambon sp. I

Leptellina pulchra Cooper Schizotreta shuleri (Willard)
Obolus nitens Cooper Skenidioides transversus Cooper
Orthambomites brachiophorus Cooper Taphrorthis peculiaris Cooper

O. divaricatus Cooper

Rob Camp formation.—This formation was named by Miller and Brosge
(1950) for heavy-bedded calcilutite with few fossils. The type locality is taken
from exposures northeast of Rob Camp Church, Coleman Gap (T.V.A. 161-SW)
Quadrangle in Virginia-Tennessee. The formation lies between the Poteet and
Martin Creek limestones. No identifiable brachiopods have been found in this
formation.

Rockdell formation.—This name was proposed by B. N. Cooper (1945b,
p. 137) for a unit composed of the Peery and Ward Cove formations where they
are inseparable. The formation consists of 58 to 420 feet of fine-grained, dark-
gray limestone and gray calcarenite. The type section is near Elk Garden, Russell
County. The formation is sandwiched between the Lincolnshire and the Ben-
bolt formations. Nidulites is present in the dark limestones. See Ward Cove
for brachiopods.

Rodman member of Nealmont formation.—According to the writer’s ob-
servations, this member is really two facies rather than a true member. In cen-
tral Pennsylvania it generally consists of about 30 feet of coarse calcarenite (simi-
lar to St. Luke facies) containing an abundance of fossils. It occurs at the top
of the Nealmont formation and underlies the Salona formation. In places the
top of the Nealmont is not calcarenite but consists of thin-bedded limestone, the
bedding being marked by thin, dark shale partings. This lithology has also been
placed in the Rodman. The list of species presented below is composed from a
list presented by Field (1919, p. 424) together with the species identified by
the writer.

Bilobia hemispherica Cooper
*Christiama trentonensis Ruedemann
Dalmanella n. sp.

*Dinorthis pectinella (Emmons)
Glyptorthis n. sp.

88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Leptaena charlottae Winchell and Schuchert = Limbimurina insueta Cooper
Leptaena n. sp.
*Orthis disparilis Conrad

O. tricenaria Conrad = Hesperorthis virginiensis Cooper

Oxoplecia n. sp. = O. pennsylvanica Cooper

Parastrophia hemiplicata (Hall) = Parastrophina hemiplicata (Hall)
*Pionodema subaequata (Conrad)

Plectambonites n. sp. = Sowerbyella n. sp.

Plectorthis pennsylvanica Cooper

Protozyga exigua (Hall)

Rafinesquina alternata (Conrad) = R. trentonensis (Conrad)
Sowerbyella sp. 2

Correlation of Rodman member—The Rodman member is clearly related to
the Oranda formation of Virginia, Maryland, and southern Pennsylvania. This
is indicated by the presence of Christiania, Bilobia, Hesperorthis, Leptaena, Rafi-
nesquina, and Parastrophina. Furthermore, the member lies under the Salona, in
the same position occupied by the Oranda near Green Mount Church, north of
Harrisonburg in Virginia.

Row Park formation.—This formation was named by Neuman (1951, p.
278) for a sequence consisting of two facies, one granular limestone and the
other calcilutite, ranging in thickness from 30 to 680 feet and extending from
Bessemer, W. Va., through Maryland into southern Pennsylvania. The type
section is 0.2 mile northwest of Row Park, Md., about 7 miles west of Hagers-
town. The granular limestones are best developed on the east side of the Massa-
nutten syncline. In the western exposures the formation is composed mostly of
calcilutite. The Row Park rests unconformably on the Beekmantown and is
overlain by New Market limestone to which it is partially equivalent (see New
Market).

Calcarenites in the lower part of the formation contain numerous brachiopods,
but the calcilutites usually do not contain remains of these animals. Row Park
brachiopods are:

“Camerella”’ longirostris Billings = Onychoplecia obesa Cooper
Camerella cf. C. varians Billings = C. pennsylvanica Cooper
Dactylogonia cf. D. incrassata (Hall)

Hesperorthts sp.

Mimella cf. M. vulgaris (Raymond)

Multicostella sp.

Ptychopleurella sp.

Rostricellula basalaris Cooper
R. plena (Hall)

Correlation of Row Park formation.—The Row Park formation is correlated
with the Lenoir of Tennessee and Virginia and with the Crown Point—Valcour
sequence of the Champlain Valley, N. Y. The presence of Hesperorthis and
possibly R. plena are the links to the Valcour. Crown Point elements are nu-
merous Maclurites in the lower part, Onychoplecia, and Dactylogonta.

St. Clair facies of Murfreesboro formation.—This name was proposed
by Butts (1940b, p. 126) for the purely limestone facies of the Murfreesboro
formation in Virginia, mainly northwest of the strike of Clinch Mountain. This

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 89

is now known not to be Murfreesboro, and the limestones have been placed in
other formations.

St. Luke member (facies) of Edinburg formation.—This name was pro-
posed by Cooper and Cooper (1946, p. 81) for dove-gray massive limestone beds
and calcarenites occurring between the Oranda formation above and the Nidu-
htes-Lambeophyllum beds of the Edinburg formation below. At the type locality,
1 mile S. 60° E. of St. Luke, Va., the member is go feet thick. It is often com-
posed of calcarenite which contains Cryptophragmus.

Brachiopods taken from the St. Luke member are:

Doleroides sp. Rostricellula sp.

Oligorhynchia bifurcata Cooper Zygospira sp.
Opikina sp.

Correlation of St. Luke member.—The St. Luke is correlated by Cooper and
Cooper (1946, p. 86) with the Witten formation. The presence of Cryptophrag-
mus, Zygospira, and Oligorhynchia aid in making the correlation.

St. Paul group.—This term was proposed by Neuman (1951, p. 278) as a
substitute for the outmoded and erroneous name “Stones River” as applied
throughout West Virginia, Maryland, and southern Pennslyvania. The type
section is located near St. Paul’s Church, Md., at the intersection of U. S. High-
way 40 and Maryland Highway 57, 9 miles west of the center of Hagerstown.
The group consists of the Row Park formation at the base and the New Market
formation at the top.

Salona formation.—This formation extends from Pennsylvania into northern
Virginia. It consists of black or dark argillaceous limestone and dark calcareous
shale usually with numerous fossils. In Virginia it overlies the Oranda forma-
tion and is more shaly than is usual in Pennsylvania. In the latter State the
Salona formation overlies the Rodman member of the Nealmont formation. In
Virginia much of the Salona fauna appears to have been inherited from the
underlying Oranda formation. A similar condition is true in Pennsylvania be-
cause some of the Rodman elements pass into the Salona. The trilobite Brongni-
artella is the most significant marker of the Salona formation.

Brachiopods are numerous. For a faunal list of the Salona fauna in Virginia,
see Martinsburg. Additional brachiopods from the Salona (Kay, 1944, p. 112)
of Pennsylvania are:

Colaptomena leptostrophoidea Cooper

Conotreta rustit Walcott

Dalmanella sp.

Leptaena sp. aff. L. rhomboidalis (Wilckens) = L. ordovicica Cooper
Leptelloidea pisum (Ruedemann) = Bilobia hemispherica Cooper
Oxoplecia sp. cf. simulatrix (Bassler) = O. pennsylvanica Cooper
Parastrophina hemiplicata (Hall)

Porambonites sp. = Porambonites sp. 4

Salonia magnaplicata Cooper and Whitcomb

Sowerbyella cava Cooper

Sowerbyella sp.

Strophomena sp.

Rafinesquina sp.

go SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Sevier formation (=facies).—This name is applied to a thick series of
sandy shales and fine-grained sandstones with intercalated beds of calcarenite,
bryozoan “reefs,” and thin lenses of sandy limestone. The color of the rock is
blue-gray when fresh but weathers to a dull yellow. The formation is very thick
and is best developed in the belts south of Knoxville and along the Great Smoky
Mountain Front into northern Georgia. In the vicinity of Friendsville the Sevier
formation overlies the Red Knobs formation and contains fossils that suggest a
Benbolt age. In the belt along the Great Smoky Mountain Front, on the other
hand, the Sevier formation is very extensive. In northern Georgia, near the
village of Cisco, Sevier-type lithology succeeds Tellico sandstone and extends
to the base of the Bays red beds. The Sevier appears to be a facies rather than
a definite formation.

In Guthrie Gap, southeast of Whitehorn, Bulls Gap (T.V.A. 171-SE) Quad-
rangle, fossils have been taken from Sevier-type rock at the church in the gap
which indicate a correlation of that part of the Sevier with the Witten formation.
In the vicinity of Fourmile Church, Tallassee (T.V.A. 139-SE) Quadrangle,
fossils taken just under the Bays red beds contain Pionodema and are thus like-
wise indicative of a Witten age. The evidence indicates that the Sevier ranges
from Benbolt to as high as Witten in the standard section.

The subjoined list indicates the species that have been identified from the
Sevier formation, and in the right-hand column the probable level from which
each was taken.

Chaulistomella brevis (Willard) Benbolt-Wardell equivalent
Cyclospira sulcata Cooper Wardell :
Cyrtonotella magna Cooper Benbolt -
Dactylogoma sp. 4

Dinorthis tenuis Cooper

D. transversa Willard
Glyptorthis subcarinata Cooper
G. uniformis Cooper
Hesperorthis dubia Cooper
Multicostella robusta Cooper
Oligorhynchia angulata Cooper
O. bifurcata Cooper Witten i.
Oxoplecia multicostellata Cooper Benbolt ¥
O. planiventra Cooper ms
Paurorthis ponderosa Cooper
Rhipidomena filicostellata Cooper
Sowerbyites delicatus Cooper
Sphenotreta cuneata Cooper Witten is
Teratelasma neumani Cooper Benbolt
Zygospira mediocostellata Cooper Witten
Zygospira sp. " a4

The lower part of the Sevier just above the Meadow marble contains many
species suggestive of Hogskin affinities. This is taken as a facies development
in the lower yellow shales of the Sevier which are similar to the Hogskin shale.

Shannondale member of Benbolt formation.—This is another name of

PART ad CHAZYAN AND RELATED BRACHIOPODS—COOPER gI

Cooper and Prouty (1943, p. 868) for argillaceous, dark-gray, nodular-weather-
ing limestone, often with a dark, bluish-gray coarse-grained limestone at the
base. These coarse-grained rocks are local in their development. The member
is variable in thickness but attains 100 feet. It is named from exposures along
the northwest base of East River Mountain south of Shannondale on U. S. High-
way 19. Cooper and Prouty (1943, p. 870) report the following brachiopods:
*Camerella quadriplicata (Willard)

*Camarella cf. C. varians Billings

Campylorthis sp. = Chaulistomella sp.

Dinorthis quadriplicata Willard = D. transversa Willard
*Glyptorthis bellarugosa (Conrad)

Mimella melonica (Willard) = M. globosa (Willard)
*Opikina “minnesotensis” (N. H. Winchell)
*Plectorthis cf. P. exfoliata Raymond

Piychoglyptus sp. (probably Bellimurina sp. True Ptychoglyptus not seen this high by the

writer)
*“Rafinesquina”’ cf. R. deltoidea (Conrad) = Opikina
*“Rafinesquina” sp. = Opikina

Sowerbyella sp.

Strophomena tennesseensis Willard = Rhipidomena tennesseensis (Willard)
*Zygospira” cf. Z. acutirostris (Hall) = Sphenotreta cuneata Cooper ?

Shippensburg formation.—This formation with type section in the railroad
cut 24 miles southwest of Marion, Pa., was defined by Craig (1949, p. 717).
In the eastern belts of south-central Pennsylvania the formation attains its great-
est thickness of 416 feet. Here it is divided into two members: Pinesburg and
Fannettsburg. In the western belts the formation is thinner, but there a third
member, the Doylesburg, appears above the Fannettsburg. The Shippensburg
formation consists of five lithologic types: Dark-gray, fine-grained cobbly lime-
stone ; fine-grained, dark-gray and evenly bedded limestone ; medium to coarse
calcarenite; interbedded dark-gray, medium-grained limestone; and calcilutite
pellet conglomerate and dove calcilutite. The brachiopod content of the formation
is discussed under the individual members.

Snyder member of Benner formation.—Described by Kay (1944, p. 15)
for a calcilutite attaining a thickness of 110 feet in central Pennsylvania; this
member forms the lower part of the Benner formation. Conglomerates with white
limestone pebbles are diagnostic of the member, which has not yet yielded
brachiopods.

Speers Ferry formation.—This name was used by Ulrich (1939, p. 106)
in a correlation chart, but no description was ever published to validate it. On
that chart the formation appears in a column headed Clinton and Pearisburg
troughs. It is placed between the Ottosee below and the Pierce formation above.
According to present understanding of Appalachian stratigraphy, this position
is impossible. The Speers Ferry may have been designed for the beds now
called Wardell.

Stones River group.—This is a group term (see C. W. Wilson, 1949)
which, after some refinements, was made to contain four formations in ascend-

Q2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ing order: Murfreesboro, Pierce, Ridley, and Lebanon. Although the Carters
formation which succeeded the Lebanon was originally included in the Stones
River group by Safford, it was thrown out by Ulrich and Bassler because it
was correlated with the Lowville and could not be included in their Chazyan
Stones River group. Views on this subject have lately changed, and it has been
shown that the rocks of the Stones River group of the Central Basin of Tennes-
see were deposited after those of the Chazy (G. A. Cooper in Schuchert, 1943,
p- 474; B. N. Cooper, 1945a, pp. 262-275). In 1949 C. W. Wilson (p. 24)
returned the Carters (originally Carters Creek) formation to its old position
at the top of the Stones River group.

The term “Stones River group” is appropriate to the Central Basin of Ten-
nessee and possibly parts of Alabama but not to most parts of the Appalachians
to which it has already been applied. For years this term has been used for the
lower or “Chazyan” part (Lenoir through Lincolnshire) of the Appalachian
section from Pennsylvania to Alabama. It was also just as inappropriately ap-
plied to parts of the Minnesota section. Identification of the Carters formation
of the Central Basin as Lowville, because of the presence of Tetradiwm cellulo-
sum, was the chief factor in declaring the subjacent beds, Lebanon through Mur-
freesboro, as Chazyan in age. A similar error was made in the Appalachians in
identifying all the formations below the Cryptophragmus and Tetradium cellu-
losum-bearing ‘““Lowville” as Chazyan in age. This threw the lower formations
of the Appalachians into correlation with the Stones River formations. Thus,
because of the common presence of Maclurites and the position in relation to
“Mosheim” rocks, Lenoir and Ridley were correlated, and from these false
premises many other errors were brought about which are detailed by B. N.
Cooper (1945a). (See Chickamauga. )

Examination of the fossils of the Stones River formations of the Central Basin
of Tennessee shows that the affinities of this group are with the old Black River—
Trenton (Wilderness) assemblage of formations rather than with the Chazy
(Marmor). It is evident, therefore, that the Stones River as a group term
should be dropped from the Appalachians.

Stover member of Benner formation.—Mostly a dense, heavy-ledged
limestone with Camarocladia markings numerous. The formation attains a thick-
tion of about 90 feet but varies to a low of slightly less than 30 feet. The forma-
tion was described by Kay (1944, p. 17) and its type section is at Union Fur-
nace in central Pennsylvania. Cryptophragmus occurs with a few other fossils.
Brachiopods are:

Ancistrorhyncha sp. *Strophomena sp. aff. S. filitexta (Hall)
Glyptorthts sp. Strophomena sp.
*Opikina sp. cf. O. wagneri (Okulitch) Zygospira sp. cf. Z. recurvirostris (Hall)

Correlation of the Stover member of the Benner formation.—Cryptophragmus,
Camarocladia, and Zygospira indicate correlation with part of the Witten forma-
tion of Cooper and Prouty.

Strasburg formation.—This is another undefined name of Ulrich’s (1939, p.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 93

106) which appears on a chart. This is in the Clinton and Pearisburg troughs
between the Lenoir below and the Holston above. It is thus in the position of
the Lincolnshire formation.

Surgener formation.—This name is proposed by B. N. Cooper and G. A.
Cooper for chalky-weathering dark limestone, cherty dark limestone, gray to
buff mudstone, and maroon mudstone that occupy an interval from about Elway
through Peery. The name is used in southwestern Virginia and adjacent parts
of East Tennessee. The name is taken from a small cemetery 4 mile due east of
the section along Yellow Creek, Rose Hill (T.V.A. 161-NE) Quadrangle, but
the type section is just east of the Hagan Switchback on the L. and N. RR., 44
miles due north of Surgener Cemetery, Rose Hill (T.V.A. 161-NE) Quad-
rangle. The Surgener is also well displayed at the south (blind) end of the
Hagan Switchback. Good sections occur at Hagan, Dryden, and Yellow Branch,
Va., and at Rose Hill and near Andersonville Dock, Tenn. At Hagan the
sequence embraces the Poteet, Rob Camp, and Martin Creek formations of
Miller and Brosge (1950). These names may be consulted for lists. Thin marine
fingers in the maroon and buff mudstones near Rose Hill, Tenn., produced
Oligorhynchia bifurcata Cooper and Plectocamara. Other brachiopods taken
from the Surgener formation are:

Ancistrorhyncha crassa Cooper
Rhipidomena tenuitesta (Willard)

Tellico formation.—This name is used for a predominantly clastic forma-
tion occurring in the southeastern belts of the Southern Appalachians in East
Tennessee and northern Georgia. Neuman (1956) has amplified this name to in-
clude shales equivalent to Upper Athens, the Tellico sandstone, and lower part
of the Sevier. In the belt along the west front of the Great Smoky Mountains
the formation is several thousand feet thick and consists of some thick calcareous
sandstones and sandy shales. These weather to a red or brown soil by leaching
of the lime, and produce lines of knobs. Rocks identified as this formation are
also developed in the belts north to Knoxville, but uncertainty exists as to their
identification with the Tellico of the type belt along the Great Smoky Front. In
these belts considerable hematite and marble containing numerous fossils occur
in the formation.

In its type belt the Tellico overlies shales (Blockhouse) with graptolites that
are only partially equivalent to the Athens formation; the Tellico is overlain
by shales and sandstones (Sevier) of uncertain correlation. In the belts passing
through Friendsville and Knoxville the sands and calcarenites mistaken for
Tellico overlie “Holston” marble (= Red Knobs) and are overlain by the Sevier
formation. In this belt “Tellico” fossils are clearly related to those of the Arline
formation and possibly fossils occurring as high as Benbolt. It is probable, there-
fore, that the type Tellico is actually older than that of the belts north of Athens.
The entire interval of shale and sandstones from the Knox to the base of the
Sevier formation is equivalent on the basis of fossils to the interval from the

94 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

top of the Knox through the “Tellico’=Red Knobs of the belts south of
Knoxville.

Bimuria superba Ulrich and Cooper Paurorthis catawbensis (Butts)
Dinorthis tenuis Cooper P. fasciculata Cooper
Leptellina tennesseensis Ulrich and Cooper Sowerbyites lamellosus Cooper

Orthambonites newmani Cooper

Thompson Valley formation.—Prouty (1946, p. 1152) proposed this name
for the coarse calcarenite in the lower part of the Ward Cove formation in parts
of Virginia and East Tennessee. It is the coarse-grained limestone mentioned
by B. N. Cooper (1944, p. 42) in the Burkes Garden Quadrangle report. Prouty
thus restricted the Ward Cove formation to the finer-grained limestone in which
Nidulites is abundant. The Thompson Valley formation is best developed in the
median belts of the Appalachian Valley and occurs locally in the northwestern
belts. The formation thus overlies Lincolnshire (or Hogskin member) and
underlies the restricted Ward Cove. The name does not appear on the chart.
The following brachiopods have been reported:

Dactylogonia magnifica Cooper Oligorhynchia subplana Coope1
Dinorthis atavoides Willard O-xoplecia holstonensis Willard
Mimella sp. Schizambon sp.

Toqua formation (R. B. Neuman, 1956).—This is a name for a sandstone
facies of the Blockhouse formation which replaces the dark shales to the south-
west along the base of the Great Smoky Mountains in East Tennessee. The
Tellico sandstone in the section at Cisco, Ga., may be in part Toqua sandstone.

Tumbez formation.—This formation was defined by B. N. Cooper (1945b,
p- 133) with type section I mile south of Tumbez, Russell County, Va. It con-
sists of a basal boulder conglomerate succeeded by dolomite, mudrock, and
calcarenite containing Rostricellula basalaris and Mimella nuclea. It underlies
Elway and overlies the Mascot dolomite (Lower Ordovician) unconformably.
The formation is equivalent to the Rostricellula beds of the Lenoir and is also
well displayed under the Maclurites beds in a small quarry 3.4 miles southwest
of Marion, Va.

Dactylogonia alternata Cooper

Mimella nuclea (Butts)
Rostricellula basalaris Cooper

Valentine member of Curtin formation (Kay, 1944, p. 21).—Pure quarry
rock, dove calcilutite in central Pennsylvania. The only brachiopod so far
reported is a large Lingula sp.

Valley View member of Curtin formation (Kay, 1944, p. 20).—This is
the lower member of the Curtin formation of central Pennsylvania from which
no brachiopods have been reported or seen by the writer in sections studied
by him.

Vestal marble.—This name is applied to a marble 150 to 200 feet thick near
the base of Sevier formation on the south side of Knoxville. It has about the
same position as the Meadow marble.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 95

Walker Mountain sandstone member of Moccasin formation.—This
name was proposed by Butts and Edmundson (1943, p. 1678) for the upper of
the two sandstones in the Moccasin formation in the southwestern end of Walker
Mountain. No type section is designated, but the best display of the member is
said to be along Keywood Branch Road about 4 mile north of Seven Springs
and along Virginia Highway 91, about a mile northwest of McCall Gap, Wash-
ington County. No fossils have been named from the formation. It is composed
of thick-bedded, gray, quartzose rock 8 to 12 feet thick. The name is not placed
on the chart because it has little significance, but if it were placed there it would
appear in the Marion and Porterfield Quarry columns.

Ward Cove formation.—This formation was made by Cooper and Prouty
(1943, p. 863) for a limestone on the southeast side of Clinch Mountain which
overlies the Lincolnshire formation (Thompson Valley, according to Prouty)
and underlies the Peery. The type section is along State Highway 91 at the
northwest base of Clinch Mountain near Ward Cove, Tazewell County, Va. The
lower part of the formation consists of an average of 60 feet of shell breccia and
calcarenite (Thompson Valley of Prouty); the upper part is composed of 75
to 150 feet of cherty medium- to fine-grained limestone, quite argillaceous in
Burkes Garden and Thompson Valley. Prouty (1946, p. 1152) later named the
shell breccia and calcarenite portion “Thompson Valley formation.” The Ward
Cove formation is characterized by the fossil Nidulites pyriformis. Brachiopods
are fairly common but are difficult to obtain in good condition.

The formation has been recognized in several belts in East Tennessee where
it deviates from the lithology of the type area. Biohermal masses of bryozoans
occur in the belt passing through Elza, Tenn.

Camerella unicosta Cooper
Dactylogonia magnifica Cooper
Fascifera sp. 1

Glyptomena sp. 1

Lepiellina sp.

Lingula cf. L. nympha Billings = Ectenoglossa nymphoidea Cooper
Lingula sp.

Neostrophia sp. 1

Oligorhynchia angulata Cooper

O. bifurcata Cooper

O. subplana Cooper

Opikina transversa Cooper
Oxoplecia gibbosa Cooper

O. holstonensis Willard

Paurorthis fascifera Cooper
Plectocamara aseptata Cooper
Plectorthis transversa Cooper
Protozyga microscopica Cooper
Schizambon cuneatum Willard
Skenidioides mediocostatus Cooper
Sowerbyella aequistriata (Willard)
S. delicatula (Butts) = Leptellina delicatula (Butts)
S. negritus (Willard)

96 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

S. parva Cooper
Strophomena tenuitesta Willard = Rhipidomena tenuitesta (Willard)
*Zygospira sp.

Correlation of Ward Cove formation.—This formation in the western belts of
Virginia takes the place of the Arline formation and has species related to the
Arline.

Wardell formation.—This formation was proposed by Cooper and Prouty
(1943, p. 873) with type section near the settlement of Wardell near the Taze-
well—Russell County line. The formation has a thickness of 200 feet or more
in median and southeastern belts of the Appalachians in Virginia and Tennessee.
The lithology is variable and consists of limestones, calcarenites like the Effna,
dove calcilutites, and shales. Where the Gratton is not present the formation
is difficult to separate from the Benbolt, as at Rye Cove, and the two combined
are known as Dryden formation. The fauna, however, is very prolific and
abounds in brachiopods. The list includes identifications by Cooper and Prouty
with additions by the writer:

Ancistrorhyncha costata Ulrich and Cooper

A. crassa Cooper

Bellimurina sp. 2

Camerella plicata Schuchert and Cooper

Camarotoechia ? plena (Hall) = Rostricellula rostrata Ulrich and Cooper
Chaulistomella inaequistriata Cooper

C. rectangulata Cooper

Dinorthis transversoides Cooper

Doleroides regularis Cooper

Fascifera stonensis (Safford)

Glyptorthis irregularis Cooper

Glyptorthis sp.

Hesperorthis cf. H. tricenaria (Conrad) = H. australis Cooper
*Mimella globosa (Willard)

M. wardellana Cooper

Murinella muralis Cooper

Oligorhynchia elongata Cooper

Oligorhynchia sp.

Opikina speciosa Cooper

O. subplanodorsata Cooper
*Pionodema subaequata (Conrad)

P. subaequata circularis (Winchell) = Fascifera subcarinata Ulrich and Cooper
Plectocamara erecta Cooper

Protozyga rotunda Cooper

Rostricellula ovata Cooper

Rostricellula sp. 2

Schizambon lineatum Cooper

S. macrothyris Cooper

Sowerbyella aequistriata (Willard)

S. socialis Cooper

S. socialis crassa Cooper
*Strophomena cf. S. emaciata Winchell and Schuchert

S. incurvata ? (Shepard) = S. medialis Butts

S. inspeciosa Willard

Valcourea cf. V. deflecta (Conrad) = Chaulistomella inaequistriata Cooper

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 97

Correlation of Wardell formation—The Wardell formation appears to be the
equivalent of the Ridley limestone in the Appalachian Valley. This equivalence
is shown in the common presence in the two formations of Fascifera stonensis,
Ancistrorhyncha costata, and Opikina speciosa. The Wardell and Ridley also
see establishment of the genus Strophomena which appeared in Murfreesboro.
The Wardell is the level at which Doleroides appears in abundance and virtually
displaces Mimella, which is commonest below. The Wardell thus contains a
more modern fauna than that of the Benbolt below, and the New York—Canada
elements become conspicuous. Most of the genera of the Benbolt suite fail to
pass over into the Wardell.

Wassum formation (B. N. Cooper and G. A. Cooper).—The Wassum for-
mation consists of Solenopora- and Stromatocerium-bearing calcarenites and
buff crumbly shales with Receptaculites, which underlie the red sandy mudstones
of the Bays formation and which succeed the black petroliferous limestones of
the Chatham Hill formation. The type locality is 4 miles northwest of Marion,
Marion (T.V.A. 218-SE) Quadrangle, Smyth County, Va. In the type locality
the formation is about 125 feet thick and composed principally of variegated
marble or calcarenite. On Walker Mountain south of Chatham Hill, Smyth
County, Va., the Wassum formation is fully exposed with a total thickness of
about 150 feet. The fossils and position of the Wassum formation place it oppo-
site the upper part of the Wardell and part of the Dryden formations of middle
and western belts of the Appalachian Valley. The formation extends northeast-
ward in one persistent belt of outcrop to Sinking Creek Valley, Giles County,
Va., where it carries Favistella halli and Stromatocerium in abundance.

Whistle Creek formation.—This name is applied by Cooper and Cooper
(1946, p. 74) to dark, cherty limestones underlying the Lincolnshire or its equiva-
lent along U. S. Highway 60 and Whistle Creek, northwest of Lexington, Va.
The full extent of this formation is not yet known. Fossils are abundant in
many places and often weather out of the limestone by solution, The known
brachiopods are:

Atelelasma perfectum Cooper ? Multicostella quadrata Cooper
Camerella globularis Cooper Murinella parva Cooper
Dactylogonia sp. 7 Opikina sp. 5

Dinorthis holdem (Willard) Oxoplecia costellata Cooper
Hesperorthis longirostris Cooper Protozyga nasuta Cooper
Macrocoelia elegantula Cooper Rhipidomena

Mimella intermedia Cooper Valcourea austrina Cooper

M. virginiensis Cooper

Correlation of Whistle Creek formation—The Whistle Creek formation is
related to the Elway formation by virtue of the common presence of Dinorthis
holdent.

Whitesburg formation.—This formation was so ambiguously defined that
the name is no longer of any use outside its type locality. At the type section
24 miles southeast of Whitesburg, on Bulls Gap (T.V.A. 171-SE) Quadrangle,
siliceous limestones about to feet thick rest on the Maclurites beds of the Lenoir
formation. The siliceous limestones contain Christiania and other fossils char-

98 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

acteristic of the Botetourt or Fetzer formations. These siliceous limestones are
overlain by about 600 feet of slabby, carbonaceous limestone and shaly limestone
similar lithologically to the Liberty Hall facies of Virginia.

Only at the type section is the Whitesburg of such great thickness. Wherever
it was recognized elsewhere by Ulrich and Butts it is some 50 feet or less thick
and is a siliceous, brown-weathering, resistant limestone underlying the “Athens”
but overlying “Lenoir” or “Holston.” The Lenoir and Holston in these instances
are the Lincolnshire and Murat formations. In Catawba Valley this remnan-
tal Whitesburg is well developed and interfingers with Effna limestone. Cooper
and Cooper (1946, p. 80) named this resistant thin bed the Botetourt member
(now formation) of the Edinburg formation.

In Alabama the Pratt Ferry limestone of Cooper and Cooper was also referred
by Butts and Ulrich to the Whitesburg formation, but it actually occupies a posi-
tion somewhere within the Little Oak. Inasmuch as the several hundred feet of
the Whitesburg, like the Virginia “Athens,” are conspicuous in the Bulls Gap
area, the name is used locally.

Dark, thin-bedded limestone overlying the Effna formation at Porterfield
Quarry near Saltville, Va., carries a holdover fauna of the Effna and is here as-
signed to the Rich Valley formation. Brachiopods of the Whitesburg are:

Anisopleurella inaequistriata Cooper L. spicata Cooper

Camerella sp. 4 Multicostella bursa (Raymond)
Conotreta magna Cooper Paterula perfecta Cooper

C. multisinuata Cooper Trematis ? parva Cooper
Ectenoglossa nymphoidea Cooper Trematis sp. 1, 2

Elliptoglossa ovalis (Bassler) Triplesia sp. 1

Leptellina bella Cooper W estonia sp. 1

Lingulella lirata Cooper

Witten formation.—This name was proposed by Cooper and Prouty (1943,
p. 877) for limestones overlying the red Bowen formation in Virginia and East
Tennessee. The formation is especially characterized by Crytophragmus which
is often found in calcarenites. Camarocladia-bearing limestone is also a promi-
nent feature of the formation. In places tongues of mudrock appear. The forma-
tion is widespread in southern Virginia and many of the belts of East Tennessee.
The red Bowen formation usually separates the Wardell and Witten formations,
but where it is absent faunal differences may be relied on. The Witten forma-
tion contains numerous brachiopods, but they are often not well preserved or are
difficult to extract from the rock. Brachiopods are as follows:

Doleroides sp. Rostricellula compressa Cooper
Hesperorthis aff. H. tricenaria (Conrad) R. subtransversa Cooper
Oligorhynchia bifurcata Cooper Sowerbyella cf. S. lebanonensis Bassler
Pionodema minuscula Willard Zygospira “recurvirostris” (Hall)

Correlation of Witten formation.—This formation is correlated with the Leba-
non of the Central Basin of Tennessee because of the common presence of Piono-
dema minuscula Willard and Rostricellula compressa Cooper. It also records
the earliest occurrence of Zygospira in the Appalachians.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 99

Woodway formation.—This formation name was proposed by Miller and
Brosge (1950) for cryptocrystalline, tan and gray limestone with interbeds and
zones of medium-crystalline limestone. A prominent zone of Stromatocerium
rugosum occurs at the base. The formation is named from exposures on the
slope of Wallen Ridge east of Woodway, Stickleyville (T.V.A. 179-NW) Quad-
rangle, Va. Brachiopods occurring in this formation are:

Ancistrorhyncha costata Ulrich and Cooper

Doleroides cf. D. gibbosus (Billings)

Hesperorthis aff. H. tricenaria (Conrad) = H. australis Cooper
Pionodema minuscula Willard

Protozyga sp.

Rostricellula sp.

Strophomena sp.

Zygospira recurvirostris (Hall)

Besides the Stromatocerium this formation contains Crypiophragmus. The
former is more commonly a Wardell species, and the latter belongs to the Witten
formation as a rule. It is evident, therefore, that Miller and Brosge’s Woodway
formation includes parts of the Wardell (=Upper Dryden) and Witten forma-
tions. Of the brachiopods the Ancistrorhyncha and Hesperorthis australis are
Wardell fossils. Pionodema and Zygospira are Witten guide fossils.

Yellow Branch member of Poteet formation (B. N. Cooper and G. A.
Cooper).—This thin but easily recognizable unit corresponds to the “nine-foot
limestone bed” of Butts (1940b, p. 122, pl. 24, C) in the much-discussed section
along Yellow Branch (so called locally, but Yellow Creek on the Rose Hill
Quadrangle), 54 miles south of Hagan and 2 miles north of the Tennessee line,
Rose Hill (T.V.A. 161-NE) Quadrangle. The formation is gray, thick-bedded
calcarenite about 8 or 9 feet thick, and carries fossils that make it of special in-
terest. The brachiopod genera Mimella, Glyptorthis, Camerella, and Murina
are suggestive of the upper Ridley, although Butts classed the beds in the Mur-
feesboro limestone. The Yellow Branch member is also fully exposed along
the L. and N. RR. switchback south of Hagan, Lee County, Va.

Camerella edmundsoni Cooper Mimella globularis Cooper
Dactylogonia sp. 8 Murinella muralis Cooper
Glyptorthis senecta Cooper

5. THE CENTRAL BASIN OF TENNESSEE, WELLS CREEK BASIN AND
HIGH BRIDGE, KENTUCKY

The early Middle Ordovician sequences of the Central Basin of Tennessee
and High Bridge, Kentucky, are composed of limestones closely related faunally
to the upper part of Southern Appalachians sequence. A complete section from
the Lower Ordovician to the Trenton is not exposed in either area because the
bottom portion, probably several hundred feet thick, is under cover.

100 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

CENTRAL BASIN OF TENNESSEE

The formations of interest here in the Central Basin are the Stones River
group and the Hermitage formation. The Stones River group, as redefined by
C. W. Wilson (1949, pp. 24-75) consists of five formations from the bottom:
Murireesboro, Pierce, Ridley, Lebanon, and Carters limestones.

Murfreesboro formation.—This formation consists of about 70 feet of dark-
gray, cherty, moderately heavy-bedded limestone on the outcrop. Collins and
Bentall (1945) report approximately 400 feet of this formation in wells drilled
in central Tennessee. Fossils are common but are usually silicified and enclosed
by chert. The fauna abounds in gastropods, but a few brachiopods have been
reported by Bassler, as follows: Dinorthis deflecta (Conrad), Orthis tricenaria
Conrad, Pianodema (sic) subaequata (Conrad), and Strophomena filitexta Hall.
In four visits to the Central Basin the writer has been unable to verify this list ex-
cept for the presence of an abundant strophomenoid. No specimens from the Mur-
freesboro formation in the National Museum or in the Schuchert Collection at
Yale University corroborate the first three species. Murfreesboro brachiopods
are:

Camerella nuda Cooper Protozyga untplicata Cooper
Murinella sp. 1 Strophomena planobesa Cooper
Plectorthis sp. 2

Correlation of Murfreesboro formation—The Murfreesboro formation is gen-
erally correlated on fossils other than brachiopods. It contains a scaphopod, Poly-
lopia billingsi (Safford) in abundance. B. N. Cooper (1944, pp. 69-71) correlates
the Murfreesboro formation with the Peery formation of Tazewell County. As ex-
plained under the Chickamauga limestone, the Murfreesboro formation is present
in northwestern Georgia but its correlation elsewhere is not clear. A representa-
tive of it may occur in Missouri in the Rock Levee formation. The Blackford
has nothing to do with Murfreesboro.

Pierce formation.—This formation consists of 27 feet of thin-bedded lime-
stone separated by shaly partings. Fossils, particularly bryozoans, are abundant.
The following brachiopods are known:

Ancistrorhyncha costata Ulrich and Cooper Opikina ? planulata Cooper

Bellimurina concentrica Cooper Philhedra minor Cooper

Doleroides regularis Cooper Protozyga sp.

Doleroides sp. I Rostricellula rostrata Ulrich and Cooper
Fascifera stonensis (Safford) R. variabilis Cooper

Glyptorthis irregularis Cooper Strophomena planobesa Cooper

Mimella biconvexa Cooper

Pionodema subaequata has also been reported but was not seen by the writer.
The report is probably erroneous. A small Mimella may have been confused
with the punctate genus, an error that is frequently made.

Correlation of Pierce formation—The Pierce formation is closely related to
the Ridley formation which overlies it, and the two may be only facies of each
other. In Sequatchie Valley, Tenn., Pierce has been identified, but there, too, it

PARTE CHAZYAN AND RELATED BRACHIOPODS—-COOPER IOI

is probably a shaly part of the Ridley. This seems to be the case in northwestern
Georgia where the Ridley is partially a shaly facies. Fascifera appears in all the
shaly facies, and F. stonensis is identified in the Wardell formation which is cor-
related with the Ridley.

Ridley formation.—This consists of about 93 to 115 feet of dark cherty
limestone containing an abundance of fossils, often beautifully silicified. In places
the coral Tetradium is common, and Opikina occurs in countless numbers at
the top of the formation. Brachiopods identified are:

Ancistrorhyncha costata Ulrich and Cooper

Camerella varians = C. plicata (Schuchert and Cooper)
C. pulchra Cooper

Chaulistomella superlata Cooper (in Georgia)
Dinorthis deflecta = Chaulistomella ridleyensis Cooper
Doleroides crassus Cooper (Georgia)

D. extensus Cooper (Georgia)

Fascifera subcarinata Ulrich and Cooper

Glyptorthis multicostellata Cooper (Georgia)
Heberiella bellarugosa = Glyptorthis assimilis Cooper
Mimella biconvexa Cooper

M. globosa (Willard) (Georgia)

Opikina maja Cooper

O. quadrata Cooper

O. speciosa Cooper

Orthis tricenaria Conrad = Hesperorthis australis Cooper
Petrocramia sp. 1 (Georgia)

Pianodema subaequata (probably a misidentification)

P. stonensis (Safford) = Fascifera stonensis (Safford)
Protorhyncha rideleyana (Safford) = Ancistrorhyncha costata Ulrich and Cooper
Protozyga rotunda Cooper

Rafinesquina incrassata (Hall) = ?

Rostricellula rostrata Ulrich and Cooper

R. variabilis Cooper

Strophomena filitexta = S. basilica Cooper

S. planobesa Cooper (in Sequatchie Valley)

Correlation of Ridley formation—tThe correlation of the Ridley formation is
with the Wardell of the Southern Appalachians. This is based on the common
presence of Fascifera, Hesperorthis australis, Opikina speciosa, and Ancistro-
rhyncha costata. The Ridley of the Central Basin of Tennessee with its scattered
and light-colored chert cannot be correlated lithologically with the “Lenoir” of the
Appalachians which has black chert. Furthermore, the “Lenoir” of the Appa-
lachians includes a variety of formations, none of which is faunally like the Rid-
ley. Certainly the Lenoir as now restricted has no species in common with the
Ridley. Correlation of the Ridley of northwestern Georgia is discussed under the
Chickamauga.

Lebanon formation.—This formation consists of approximately 100 feet of
thin-bedded limestone separated by thin beds of shale often containing exquisite
fossils. Camarocladia markings are frequent and conspicuous. A thick bed of
calcarenite (about 3 feet thick) containing abundant Cryptophragmus occurs

102 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

near the middle of the formation in the vicinity of Readyville. The following
brachiopods have been identified:

Acanthocrania sp. 1

Ancistrorhyncha australis (Foerste)

Bellimurina parviplicata Cooper

Camarotoechia orientalis = Rostricellula compressa Cooper
Didymelasma longicrurum Cooper

Dinorthis deflecta = Chaulistomella lebanonensis Cooper
Doleroides tennesseensis Cooper

Hallina saffordi (Hall)

Hebertella bellarugosa = Glypthorthis irregularis Cooper
*H. borealis (Billings) = probably a misidentification
Opikina eximia Cooper

O. septata Salmon

Orthis tricenaria = Hesperorthis quadrata Cooper
Pianodema subaequata = Pionodema minuscula Willard
Plectorthis lebanonensis Cooper

Protozyga rotunda Cooper

Rostricellula compressa Cooper

R. truncata Cooper

Skenidioides halli (Hall and Clarke)

Sowerbyella lebanonensis Bassler

Strophomena filitexta = S. grandimusculosa Cooper
Triplesia subcarinata Cooper

Zygospira circularis Cooper

Z. elongata Cooper

Z. lebanonensis Cooper

Z. saffordi Winchell and Schuchert = Hallina saffordi Winchell and Schuchert

Correlation of Lebanon formation.—The Lebanon limestone is correlated with
the Witten limestone of the Appalachian Valley. These two formations have
Pionodema minuscula, Doleroides, Rostricellula compressa, and abundant Zgyo-
spira in common. The presence of Triplesia subcarinata, which is quite similar
to T. extans, is a link to the Rockland of New York and Ontario. In addi-
tion to the brachiopods the Lebanon and Witten share Cryptophragmus and
Camarocladia.

Carters formation (originally Carters Creek).—C. W. Wilson (1949, pp.
50, 58) divides this formation into lower and upper members and drops the
name Tyrone, from the Central Basin of Tennessee, hitherto used for the upper
member. The lower member is generally heavy-bedded and abounds in coral-
line animals: Foerstephyllum, Stromatocerium, Solenopora, Dystactospongia,
and Streptelasma. The rock is calcarenite with some fine-grained layers. The
average thickness is about 50 feet, but the range of thickness is from 27 to 95
feet. The contact between the Lebanon and the lower Carters is disconformable.
No brachiopods are recorded from the lower Carters.

The upper member of the Carters formation is composed mostly of thin-bedded
limestone, dove colored, and with the layers often separated by thin shale part-
ings. The rock contains Tetradium cellulosum in abundance. This is the part
referred to the Lowville of New York by Ulrich and was the basis for identify-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 103

ing the members of the Stones River group below the Carters as equivalent to
the New York Chazy. Brachiopods from the upper Carters are:
Camerella bella Fenton

Chaulistomella lebanonensis Cooper

Chaulistomella sp. 1

Craniops attenuata Cooper (in Alabama)

Doleroides tennesseensis Cooper

Fascifera sulcata Cooper

Hesperorthis “tricenaria”

Opikina varia Cooper

Oxoplecia planulata Cooper (Alabama)

Sowerbyella subcarinata (Ulrich) (Alabama)

Strophomena filitexta = S. auburnensis nasuta Cooper (Sequatchie Valley)
S. platyuwmbona Cooper (Alabama)

Zygospira circularis Cooper

Correlation of Carters formation.—The Carters formation is identified in the
Appalachian Valley and Sequatchie Valley with the Hardy Creek and Cane Creek
formations of southwestern Virginia.

“Kimmswick” limestone.—Ulrich (1911, p. 310) reported Kimmswick lime-
stone near Aspen Hill, Giles County, Tenn. This rock, which is a coarse cal-
carenite about 35 feet thick, contains the ball-cystid Echinosphaerites and Re-
ceptaculites oweni, both characteristic of the Kimmswick of Missouri. C. W.
Wilson (1949, p. 66), in mapping the Carters formation, discovered that the
lower Carters member grades into the calcarenites of the “Kimmswick” and
that typical Carters fossils occur in the Kimmswick facies as well as in the lower
Carters facies. This, then, is corroboratory evidence that the Kimmswick of
Tennessee equals Carters and that the Carters itself is of Trenton age. Brachio-
pods reported from the Tennessee “Kimmswick”’ are:

Rafinesquina cf. R. minnesotensis

Rhynchotrema minnesotensis
Strophomena cf. S. scofieldi = Furcitella scofieldi (Winchell and Schuchert)

Correlation of “Kimmswick” limestone.—It is suggested here that this “Kimms-
wick,” which is a facies of the Carters, correlates with the Oranda formation of
the Appalachian Valley. The latter formation also contains a large Receptaculites
but is probably older than the Kimmswick of the Mississippi Valley which con-
tains Platystrophia, a genus not yet taken in the Appalachians as low as the
Oranda.

Hermitage formation.—The Carters is succeeded by a complete change of
lithology and fauna. The Hermitage, as displayed in the vicinity of Woodbury,
Cannon County, Tenn., introduces a fauna characterized by large Dinorthis and
Heterorthis clytie. C. W. Wilson (1949, pp. 82-88) places this part of the
Hermitage formation in the Curdsville member. The Curdsville fauna of Ken-
tucky and the Appalachian Valley, however, is quite different from that of the
Central Basin. In the Appalachians the Curdsville contains a large Dinorthis, to
be sure, but it also is teeming with Sowerbyella curdsvillensis and Hesperorthis
tricenaria. The assemblage, besides lacking Heterorthis, is quite different from

104. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the fauna at the base of the Hermitage. According to McFarlan (1931, p. 50),
the Hermitage of Kentucky is characterized by large Dinorthis and Heterorths.
It is the writer’s belief that the correlation of the Heterorthis assemblage with
the Curdsville is not correct. Hermitage brachiopods besides those listed are:
Dalmanella crassicostellata Cooper

D. sulcata Cooper

Dinorthis pectinella (Emmons)

Onniella ? americana Cooper

O. ? planoconvexa Cooper

Pionodema tennesseensis Cooper

Platystrophia extensa McEwen

Rafinesquina hermitagensis Bassler = R. trentonensis (Conrad) ?

Rhynchotrema “increbescens”

Rostricellula minuta Cooper

Zygospira “recurvirostris” (Hall)

WELLS CREEK BASIN

The Wells Creek Basin is a small cryptovolcanic structure located in south-
eastern Stewart County in north-central Tennessee. Bucher (1936, p. 1069)
described the structure and some of the stratigraphy of the basin. C. W. Wilson
(1949, p. 324-325) gives the most complete section and identifies the Ordovician
formations for the first time. Most of the formations of the Stones River group
are present, as follows:

RoweriGarters members, gOs954. 2czis SERINE SA PAS SE (100 feet, est.)

Eebartonylimestone, <4. 4.02% «1s, smulseny. seater e re present

Fem Py MAO SEONE os 5 2075 a aya, « ate: Seine de mcpeanapnet bois, Phe Sie present

FERC SM TMES TOME ais <<a “<4 tere ocussensieucio oucdsvelustene otereieue the not recognized but probably present
Muorireesporo limestone”... ce cect be ccccesccetnesns present

The lowest formation rests on the Wells Creek dolomite of Canadian age and
the lower Carters member is overlain by 100 feet (estimated) of Hermitage.

In 1903 Foerste (p. 705) applied the name “Wells” to limestones about 14
miles southwest of Cumberland City, along the railroad, about 4 mile south of
the crossing of the Erin Pike. The fossils from these beds were identified as an
upper Stones River assemblage. The brachiopods listed by Foerste are:

Acanthocrania cumberlandensis (Foerste)
Crania related to setigera but with surface spinose
Dalmanella subaequata var. = ? Pionodema minuscula Willard
Dinorthis deflecta= ? Chaulistomella
Hallina nicolleti = Protozyga
Orthis tricenaria = Hesperorthis tricenaria (Conrad)
*Plectambonites sericea = Sowerbyella
*Rafinesquina minnesotensis = Opikina
Rhynchotrema related to inaequivalvis but with more triangular outline and with the sides
more flattened, producing a more angular shell; probably identical with Rh. orientalis of
Safford. This description suggests Rostricellula compressa Cooper.
*Strophomena incurvata (filitexta)
Zygospira recurvirostris

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 105

This list is strongly suggestive of the Lebanon formation, but it is possible
that some Carters is represented. In addition to the above fossils the writer is
describing Eoplectodonta foerstei which is said to have come from the Lowville.
It is probable that it was derived from a part of the column now referred to
the Carters. Its occurrence is in accord with the correlation of Carters with
the Oranda.

HIGH BRIDGE, CENTRAL KENTUCKY

The sequence in the bluffs along the Kentucky River south of Lexington, Ky.,
was described by A. M. Miller (1905), A. C. McFarlan (1931, p. 49), and
G. G. Huffman (1945, pp. 165-168). The “Highbridge Series” is divided into
three formations from the bottom: Camp Nelson, Oregon, and Tyrone.

Camp Nelson formation.—This formation consists of 315 feet of mostly
dove-gray limestone, massively bedded in the lower 100 feet but becoming thinner
bedded above. Important among the fossils reported from this formation is
Cryptophragmus antiquatus (Raymond) which “forms a prominent zone (65
feet or more) in the upper go feet.” The following brachiopods are reported:
Ancistrorhyncha sp. = Ancistrorhyncha australis (Foerste)

Camarotoechia plena (Hall) = Rostricellula sp.
Chaulistomella lebanonensis Cooper

Doleroides sp.

Glyptorthis sp.

Multicostella (?) sp. aff. M. platys (Billings) = Chaulistomella sp.
Opikina eximia Cooper

Opikina sp. cf. O. minnesotensis (N. H. Winchell)
Opikina sp. cf. O. transitionalis (Okulitch)
Pionodema minuscula Willard

Pseudolingula ? sculptata Cooper

Rostricellula compressa Cooper

Strophomena sp.

Zygospira lebanonensis Cooper

Correlation of Camp Nelson formation.—The presence of Cryptophragmus
in the upper part of the Camp Nelson formation is a clue to the correlation. This
combined with the Wardell-Witten types of brachiopods indicates that the
Camp Nelson is equivalent to the Ridley-Lebanon of the Central Basin. Crypto-
phragmus occurs in the lower part of the Witten and in the middle of the
Lebanon. The correlation is thus with the lower Witten and part of the Wardell,
a correlation that is corroborated by Opikina and Ancistrorhyncha. Cryptophrag-
mus occurs in the middle of the Lebanon; therefore, the correlation is with the
lower Lebanon and probably part of the Ridley.

The above correlation is possible but may not be the true one. Inasmuch as
Cryptophragmus is commonly tied to the calcarenite facies, it may occur in any
part of the formation. If this be true, the correlation of the Camp Nelson is
more probably with Witten and Lebanon; Wardell and Ridley may or may not
be represented. The fossils listed by Huffman and recorded above are more
suggestive of high Lebanon than they are of any other part of the column, but
the thickness of the Camp Nelson is far greater than that of the Lebanon. Sower-

106 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

byella is not reported from the Camp Nelson and is rare in the upper Lebanon.
The Camp Nelson probably thins toward the Central Basin of Tennessee and
could thus be the equivalent of the Lebanon alone. The Camp Nelson forma-
tion lithologically is like the Lebanon and has Camarocladia markings like that
formation. On the chart the correlation is indicated as mainly with the Lebanon
toward the Central Basin and with Witten and part of the Wardell to the east.
Oregon formation.—This formation consists of 35 feet of cream-colored
dolomite without fossils. The bed has been correlated with the lower Carters.
Tyrone formation.—This formation consists of 75 feet of dove-gray lime-
stone with conchoidal fracture and birdseye-type calcite rods. The formation has
three metabentonites, one near the base, a second 55 feet above the base, and
the third at the top just under the overlying Curdsville formation. Fossils are
not common. The following brachiopods occur :
Idiospira panderi (Billings) *S. cf. S. plattinensis Fenton

Strophomena auburnensis nasuta Cooper Zygospira sp.
*Strophomena cf. S. dignata Fenton

Correlation of Tyrone formation—The Tyrone formation is correlated with
the Cane Creek formation of southwestern Virginia and the upper Carters of
the Central Basin of Tennessee. This correlation has hitherto been accomplished
more by bentonites (Huffman, 1945) than by fossils because so few fossils have
been taken from the formation. However, the strophomenoids are of Trenton
types and the Zygospira indicates correlation with the range of Witten to Cane
Creek.

6. THE DISTURBED AREA AT KENTLAND, INDIANA

An area of disturbed Ordovician strata occurs in the north half of sec. 25,
T. 27 N., R. 9 W., along the south line of Newton County about 3 miles east
of Kentland. Shrock (1937) describes this area in great detail. The Means
Quarry is the westernmost opening and the McKee Quarry is the easternmost
one. The middle exposure is the McCray Quarry. The sequence is divided into
12 divisions: The lowest is the Prairie du Chien and the highest is in the
Pleistocene. Divisions 1 to 9 are of interest in this discussion.

Division 1.—Consists of 15 feet of sandstone assigned to the St. Peter but no
brachiopods are reported.

Division 2.—White quartzose sandstone with a few beds containing many
mollusks of a few kinds. This bed is referred by Shrock to the Glenwood shale
and sandstone of Illinois.

Division 3.—Uncertain.

Division 4.—36 feet of light-buff, dolomitic, arenaceous limestone and sand-
stone containing Leperditia fabulites.

Division 5.—Blue-gray to light-brown somewhat dolomitic limestone, fine-
grained and arenaceous. Thickness about 20 feet. The following brachiopods are
reported :

Pholidops trentonensis minor = Craniops minor (Winchell and Schuchert)
Pionodema cf. conradi = P. conradi (N. H. Winchell)

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 107

Rafinesquina minnesotensis = Opikina minnesotensis (N. H. Winchell)
Rafinesquina n. sp. = Opikina

Rhynchotrema minnesotense = Rostricellula minnesotensis (Sardeson)
Strophomena plattinensis = S. plattinensis Fenton

S. p. crassa = S. p. crassa Raasch

Valcourea deflecta = Campylorthis deflecta (Conrad)

Zygospira saffordi = Hallina saffordi Winchell and Schuchert

Division 6.—Thirty-six feet of light-brown to buff dolomitic limestone, fine-
granular and fairly even textured in thick beds. Two brachiopods, Hesperorthis
tricenaria and Valcourea deflecta=Campylorthis, are reported.

Division 7—Limestone, dolomitic, moderately granular and heavy bedded
with numerous Cryptophragmus antiquatus. The division is about 11 feet thick.
Brachiopods reported are:

Rhynchotrema minnesotensis = Rostricellula minnesotensis (Sardeson)

Strophomena auburnensis = S. auburnensis Fenton
Valcourea deflecta = Campylorthis deflecta (Conrad)

Division 8.—Somewhat dolomitic limestone, blue-gray, white-weathering, thin-
bedded, semilithographic, separated by films of black or gray somewhat car-
bonaceous shale. The division is 58 feet thick. Fossils are abundant and include
the following brachiopods:

Crania setigera = Acanthocrania setigera (Hall)

Glyptorthis bellarugosa = G. bellarugosa (Conrad)

Hesperorthis tricenaria = H. tricenaria (Conrad)

Leptaena charlottae = Bellimurina charlottae (Winchell and Schuchert)
Rafinesquina cf. hermitagensis = R. trentonensis (Conrad)

R. minnesotensis = Opikina minnesotensis (N. H. Winchell)
Rhynchotrema minnesotensis = Rostricellula minnesotensis (Sardeson)
Strophomena trentonensis Winchell and Schuchert

Zygospira recurvirostris (Hall)

Division 9.—Sixty-five feet of cherty, dolomitic limestone containing Colum-
naria halli in abundance. Hesperorthis tricenaria and Strophomena trentonensis
are the only brachiopods reported.

Overlying Division 9 are beds referrable to Trenton rocks and higher.

Correlation of strata of Kentland area—According to Shrock and Raasch
(1937), Divisions 4 to 6 are referrable to the Platteville formation ; Division 7
is assigned to the Lowville (=Carters). Division 8 is referred to the Black
River but its lower part is thought to be Platteville. Division 9 is Black River-
Trenton by its position under Division 10, which is assigned to the Galena
formation.

Closer correlations may actually be possible in some instances, but they will
only slightly change the picture as given by Shrock and Raasch. Divisions 4 to
6 contain a number of brachiopods of which Pholidops [=Craniops] trentonensis
minor is important. In Minnesota this species occurs in the Ctenodonta bed
of the Guttenberg member. In Oklahoma Craniops occurs in the upper Bromide
of about Ridley age. The presence of Rhynchotrema [=Rostricellula] minneso-
tensis and Pionodema conradi suggest a somewhat earlier dating than Gutten-

108 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

berg. The Mollusca, particularly Salterella [Polylopia] billingsi, suggest corre-
lation with the Murfreesboro limestone of Tennessee. The ensemble seems best
placed in the position of the Platteville.

Abundance of Cryptophragmus antiquatus in Division 7 suggests assignment
to the Pamelia, Gratton, or Witten limestones, all of which contain this peculiar
fossil. The numerous species that occur in this division besides the Cryptophrag-
mus do not help in correlating with the Pamelia because so few species are known
from that formation. Not much help is to be found in these fossils of Division 7
in comparing with the Witten fauna because no important Witten elements are
included. The division could correlate with the Ridley or Wardell as well as
Witten. Strophomena auburnensis suggests correlation with the Guttenberg.

Division 8, if the reported fossils are correctly identified, is probably assign-
able to the Guttenberg member of the Decorah formation. This is based on the
presence of Rafinesquina cf. hermitagensis which seems to be identical with
R. alternata Conrad=R. trentonensis (Conrad). This division also contains
Leptaena charlottae = Bellimurina, which occurs in the Guttenberg of Minnesota.

7. THE MISSISSIPPI VALLEY

The Ordovician formations of the Mississippi Valley are best discussed in
two geographic areas: the upper Mississippi Valley and the middle Mississippi
Valley. Embraced in the former are northeastern Iowa, northwestern Illinois,
southeastern Minnesota, and southwestern Wisconsin. The latter area covers
parts of Missouri, adjacent Illinois, and Arkansas.

UPPER MISSISSIPPI VALLEY

The section in this part of the Mississippi Valley consists of the following
section from the bottom up: St. Peter sandstone, Platteville limestone, Decorah
shale, and Prosser limestone.

St. Peter sandstone.—This is a widespread formation throughout the Missis-
sippi Valley and in the subsurface of several States as far east as Indiana and
Kentucky and west to Oklahoma. The St. Peter has generally been regarded
of Marmor (Chazyan) age, but no clear faunal evidence has ever been accu-
mulated to prove this point. The formation may actually be a transgressing sand-
stone and of different age in different places as indicated on the chart. The
known fauna consists mostly of mollusks, which are the types of animal to be
expected in a sandstone environment. Sardeson (1896) lists the fauna which
includes three brachiopods: ? Crania reversa Sardeson, Lingulella morsu (N. H.
Winchell), and Orthis [Doleroides| pervetus ? Conrad. If the latter identifica-
tion be correct, the formation would be high Porterfield and not equal to Marmor
(Chazyan), at least in the upper Mississippi Valley.

Platteville formation (group of Templeton and Willman).—The Platte-
ville limestone occurs in all the States named and consists of several members
from the bottom up: Glenwood shale, Pecatonica limestone, McGregor lime-
stone Mifflin limestone, and Magnolia limestone.

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 109g

Glenwood member of Platteville formation—This member consists of green-
ish shale and ranges in thickness from 0 to Io feet but is generally from 4 to 6
feet thick. This formation, like the St. Peter below it, is widespread and may
be of different age in different places. In the bluffs on the Mississippi River,
Minneapolis, thin layers of dolomite in the green shale produced a few fossils
that ally it with the overlying Platteville: Campylorthis deflecta (Conrad).

Templeton and Willman (1952, p. 6) state that the equivalents of the Glen-
wood attain a thickness of 400 feet.

Pecatonica member of Platteville formation.—This is the Lower Buff division
of the early reports. It consists of dense, blue, buff-weathering, heavy-bedded
magnesian limestone or dolomite. This member succeeds the Glenwood in north-
ern Illinois, southwestern Wisconsin, and northeastern Iowa. Its maximum
thickness, about 30 feet, is in Illinois and it thins to disappearance to the north.
Few fossils have been listed, mostly Mollusca.

McGregor member of Platteville formation—tThis term was proposed by Kay
(1935, p- 286) to include the “Blue beds” and “Upper Buff” beds of the older
reports. In Minnesota the Vanuxemia bed is partially equivalent to the “Blue
beds.” The brachiopods listed for the McGregor in Minnesota are:
Acanthocrania granulosa (N. H. Winchell)

Crania setigera Hall = Acanthocrania setigera (Hall)

Lingula elderi Whitfield = Pachyglossa elderi (Whitfield)

Orthis tricenaria Conrad = Hesperorthis concava Cooper

O. (Dalmanella) subaequata Conrad (not seen)

O. (D.) subaequata conradi N. H. Winchell = Pionodema conradi (N. H. Winchell)
O. (D.) subaequata perveta Conrad = Doleroides pervetus (Conrad)

O. (Dinorthis) deflecta Conrad = Campylorthis deflecta (Conrad)

O. (Hebertella) bellarugosa Conrad (not seen)

Petrocrania dixonensis Cooper

Rafinesquina minnesotensis N. H. Winchell = Opikina minnesotensis (N. H. Winchell)
Rhynchotrema minnesotensis Sardeson = Rostricellula minnesotensis (Sardeson)
Siphonotreta ? minnesotensis Hall

Skenidioides anthonensis (Sardeson)

Sowerbyella sp.

Strophomena incurvata (Shepard) = S. plattinensis Fenton

S. plattinensis crassa Raasch

Trematis huronensis ? Billings

Trigrammaria winchelli (Hall and Clarke)
*Zygospira recurvisrostris (Hall)

Z. (Hallina) nicolleti Winchell and Schuchert = Protozyga nicolleti (Winchell and

Schuchert)

Stauffer and Thiel (1941, p. 77) state that although remnants of the Peca-
tonica and Magnolia members appear in Minnesota, they are not sufficiently
clear to separate, and therefore the term “McGregor” as defined by Kay is pre-
ferred. Bays and Raasch (1935, p. 298) excluded the “Upper Buff” beds from
the McGregor and proposed Magnolia for them and other overlying beds. Bays
(1938, p. 269) rejected McGregor and recognized Mifflin and Magnolia above
the Pecatonica. Satisfactory faunal lists have never been published for these
members.

IIo SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Mifflin member of Platteville formation—This name was proposed by C. A.
Bays for 174 feet of thin-bedded limestone exposed on the Pecatonica River at
Mifflin, Iowa County, Wis. This member underlies the Magnolia and overlies
the Pecatonica members. No fossils are listed.

Magnolia member of Platteville formation—This name is applied by Bays
and Raasch (1935, p. 298) to the “Upper Buff” division of earlier authors.
These are light-buff, moderately thick-bedded dolomites, thickest in south-central
Wisconsin.

Doleroides ottawanus Wilson ? S. plattinensis Fenton

Obolellina dixonensis Cooper S. plattinensis crassa Raasch.
Strophomena auburnensis impressa Raasch

Templeton and Willman (1952, fig. 3) divide the Magnolia member into two
formations which are themselves many times divided into members. The Grand
Detour formation (with seven members) attains a thickness of slightly more
than 50 feet of dolomite or limestone, thicker bedded than the Mifflin below.
The Nachusa formation (of three members) is 19 feet thick, of dolomite or
limestone, and containing Foerstephyllum and Tetradium. No brachiopods are
recorded from either formation.

Quimbys Mill member of Platteville formation——This name was proposed by
Agnew and Heyl (1946, p. 1585) for the “Glass Rock” between the Spechts
Ferry and the McGregor member of the Platteville formation. It consists of
limestone and dolomite, 12 feet thick at the type section, at old Quimby’s Mill
in SESSE4 sec. 11, T. 1 N., R. 1 E., near the Fever River at Etna, Wis. The
formation abounds in Opikina. It is placed with the Spechts Ferry by Templeton
and Willman (1952, fig. 3).

Correlation of Platteville formation.—The Platteville formation abounds in
Strophomena, Opikina, Pionodema, and Doleroides. The combination appears
in the Chaumont and extends into the early Rockland. In the Appalachians this
combination comes in with the Wardell and continues through the Lebanon. The
writer, therefore, correlates the Platteville with Chaumont and part of the
Rockland.

Decorah formation.—This formation is composed chiefly of greenish shale
with thin limestone layers. According to Kay (1935, p. 289) “Southward, the
calcareous shales pass into limestones, of which the lower, the Guttenberg mem-
ber, are gray with brown, ‘oil rock’ partings, and the upper, the Ion member,
bluish, containing intercalated greenish, calcareous shales. Northward from the
type locality, the members persist as greenish, calcareous shales.” Three mem-
bers have been distinguished from the bottom up: Spechts Ferry, Guttenberg,
and Ion.

Spechts Ferry member of Decorah formation.—Blue or green laminated shale
with a thickness from 5 to 8 feet from Platteville, Wis., to southern Minnesota.
To the north it thickens to nearly 4o feet. In Minnesota it is the Stictoporella
bed of the Minnesota Survey. The following brachiopods are reported:

Crania halli Sardeson = Petrocrania halli (Sardeson)
C. setigera Hall = Acanthocrania setigera (Hall)

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER Ii!

Dalmanella perveta (Conrad) = Doleroides pervetus (Conrad)
D. subaequata (Conrad) = Pionodema subaequata (Conrad)
Doleroides gibbosus (Billings)

D. medius (Winchell) = D. winchelli Cooper

Lingula elderi Whitfield = Pachyglossa elderi (Whitfield)
Orthis tricenaria (Conrad) = Hesperorthits sp.

Pionodema uniplicata Cooper

Plectambonites sericea (Sowerby) = Sowerbyella (not seen)
Rostricellula ainsliei (N. H. Winchell)

R. minnesotensis (Sardeson)

Strophomena incurvata (Shepard) = S. auburnensis Fenton
Trematis huronensis ? Billings = T. punctostriata Hall

T. minnesotensis Sardeson

Zygospira recurvirostris (Hall) (not seen)

Correlation of Spechts Ferry member.—This member is difficult to place be-
cause it contains elements of the fauna below but also elements of the Gutten-
berg above, such as Pionodema subaequata. The abundance of large Pionodema
and Doleroides suggests assignment to upper Plattin of Missouri and to the Car-
ters of West Tennessee. This correlation is also borne out by the large Trematis
which occurs in the top of the Plattin.

Guttenberg member of Decorah formation.—In northern Illinois this is the “oil
rock” ; in northern Iowa it is composed of grayish, shaly limestone about 13 feet
thick; in Minnesota the member consists of the Rhinidictya bed composed of
soft, dark-greenish shale, and the Ctenodonta bed characterized by pelecypods.
Brachiopods occurring in the Rhinidictya bed are:

Crania setigera Hall = Acanthocrania setigera (Hall)

Craniella ? ulrichi Hall = Petrocrania ulrichi (Hall)

Dalmanella hamburgensis Winchell and Schuchert (not Walcott) = D. winchelli Cooper

Idiospira panderi (Billings)

Leptaena charlottae Winchell and Schuchert = Bellimurina charlottae (Winchell and
Schuchert)

Lingula clathrata Winchell and Schuchert = W estonia clathrata (Winchell and Schuchert)

L. eva Billings

Orthis tricenaria Conrad = Hesperorthis tricenaria (Conrad)

O. (Dalmanella) subaequata perveta Conrad = Doleroides pervetus (Conrad)

O. (Hebertella) bellarugosa Conrad = Glyptorthis bellarugosa (Conrad)

Pionodema subaequata (Conrad)

P. uniplicata Cooper

Plectambonites sericea Sowerby = Sowerbyella punctostriata (Mather)

Rafinesquina minnesotensis inquassa Sardeson = Opikina inquassa (Sardeson)

R. prestonensis Salmon

R. sinclairi Salmon

R. trentonensis (Conrad)

Rhynchotrema ainsliei N. H. Winchell = Rostricellula ainsliei (N. H. Winchell)

R. minnesotensis Sardeson = Rostricellula minnesotensis (Sardeson)

Rostricellula pulchra Cooper

Schizocrania filosa Hall

Strophomena delicatula Fenton

S. dignata Fenton

II2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

S. incurvata (Shepard) = S. auburnensis Fenton
Trematis huronensis ? Billings
Zygospira recurvirostris (Hall) (not seen)

The brachiopods recorded from the Ctenodonta bed are:

Crania setigera Hall = Acanthocrania setigera (Hall)

Lepiaena charlottae Winchell and Schuchert = Bellimurina charlottae (Winchell and
Schuchert)

Orthis tricenaria Conrad = Hesperorthis tricenaria (Conrad)

Pholidops trentonensis minor Winchell and Schuchert = Craniops minor (Winchell and
Schuchert)

Plectambonites sericea Sowerby = Sowerbyella punctostriata (Mather)

Strophomena incurvata (Shepard) = probably S. auburnensis Fenton

Zygospira recurvirostris (Hall)

Correlation of Guttenberg member.—The Guttenberg brings the first appear-
ance in the Upper Mississippi Valley of Rafinesquina ss., Dalmanella ss., and
the large Sowerbyella. The formation is correlated with the Oranda of the
Appalachians and the Carters of West Tennessee. The Barnhart of Missouri is
thought to be a southward extension of the Guttenberg. It is uncertain in the
writer’s mind whether or not the Guttenberg is equivalent to lower Curdsville.
That formation has the large Sowerbyella and early form of Rafinesquina. The
Oranda is an earlier-deposited formation than the Curdsville and also contains
large Sowerbyella and Rafinesquina. The Collierstown, probably the lateral
equivalent of the Oranda, contains the Rafinesquina and other fossils to estab-
lish this correlation.

Ion member of Decorah formation —The 16 feet of shale and limestone form-
ing the lon member at its type section passes into limestone to the south and into
greenish shale to the north. In Minnesota this member includes the Phylloporina
and fucoid beds. These contain the following brachiopods:

Dinorthis sweeneyi (Winchell)

Glyptorthis subcircularis Cooper

Orthis tricenaria Conrad = Hesperorthis colet Cooper

O. (Dalmanella) hamburgensis ? Walcott = D. winchelli Cooper

O. (D.) testudinaria Dalman = Paucicrura rogata (Sardeson)

O. (D.) subaequata circularis N. H. Winchell = Pionodema circularis (N. H. Winchell)
O. (Hebertella) bellarugosa Conrad = Glyptorthis bellarugosa (Conrad)
Pionodema minnesotensis Cooper

P. uniplicata Cooper

Plectambonites sericea Sowerby = Sowerbyella monilifera Cooper
Rafinesquina alternata Conrad = R. trentonensis (Conrad)

R. minnesotensis inquassa Sardeson = Opikina lirata Cooper

Rhynchotrema inaequivalvis Castelnau = R. wisconsinense Fenton and Fenton
Rostricellula colei Cooper

Scenidium anthonensis Sardeson = Skenidioides anthonensis (Sardeson)
Strophomena incurvata (Shepard) = S. musculosa Fenton

S. septata Winchell and Schuchert

S. trentonensis Winchell and Schuchert

Zygospira recurvirostris (Hall)

Correlation of Ion member.—Kay (1937, p. 294) correlates the lon member
with the lower part of the Hull formation of Ontario, Quebec, and New York.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER Ts,

This member with its true Rhynchotrema, Rafinesquina, and large Sowerbyella
is of about the same age as the preceding member and is correlated with part
of the Kimmswick of Missouri and Curdsville of West Tennessee and Kentucky.

Prosser formation.—The Ion member of the Decorah formation is overlain
by rocks lithologically and faunally quite distinct from the underlying shales.
The Prosser formation overlying the Ion member is thin-bedded limestone and
calcareous shale abounding in fossils. The species occurring in this formation
introduce new elements for the upper Mississippi Valley such as Vellamo, Platy-
strophia, Furcitella scofieldi (Winchell and Schuchert). These indicate correla-
tion with the Kimmswick of Missouri and the Sherman Fall of New York and
Ontario, but these elements do not occur in the Appalachians.

Obolellina parva (Whitfield) Philhedra depressa Cooper
Parastrophina bernensis (Sardeson) Rostricellula acutiplicata Cooper
P. rotundiformis Willard Rostricellula sp. 3

The Salona of Virginia and Pennsylvania contain many Kimmswick elements
such as the ball cystid Echinosphaerites, large Parastrophina, large Sowerbyella.

Templeton and Willman (1952, p. 6 and fig. 3) propose the name Dunleith
for the combined Prosser and Ion of Wisconsin and Illinois and split their
new formation into 10 members.

UPPER MISSISSIPPI VALLEY FORMATIONS NOT IN GENERAL USE

Lowell Park member of Platteville formation.—This name was applied
by Knappen (1926, p. 54) to interbedded gray and buff heavy-bedded limestone
and coarse-grained, yellow-brown porous dolomites like the overlying Galena.
The formation is 20 to 30 feet thick. It overlies the “blue” limestone and under-
lies the Galena and thus forms the upper member of the Platteville. Brachiopods
listed are:

Leptaena charlottae Winchell and Schuchert Strophomena incurvata (Shepard)

Orthis tricenaria Conrad S. trentonensis Winchell and Schuchert
Rafinesquina minnesotensis (N. H. Winchell)

Minneapolis limestone.—This was proposed by Sardeson for the basal bed
of the Beloit formation or lower Platteville. (See Wilmarth, 1938, p. 1381.)

Beloit dolomite formation.—This is another name proposed by Sardeson
(1896) which includes the equivalents of the Decorah and Platteville. (See
Wilmarth, 1938, p. 157.)

MIDDLE MISSISSIPPI VALLEY

In this part of the Valley the section, in ascending order, consists of the
Buffalo River series, Rock Levee formation, Plattin group, Decorah formation,
Auburn chert, and Kimmswick limestone. Some members of the Buffalo River
series are well displayed in Ste. Genevieve County, Mo., and in the vicinity
of Cape Girardeau.

Buffalo River series (originally Big Buffalo series, but the name of the
Big Buffalo River, after which the group is named, was changed by the Geo-

II4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

graphic Board to Buffalo River [Wilmarth, 1938, pp. 181, 182] ).—The Buffalo
River series consists, in ascending order, of the Everton, St. Peter, Dutchtown,
and Joachim formations. These formations have not yielded brachiopods in the
lower Mississippi area except Lingulella sp. 7 from the Dutchtown formation
and are therefore not discussed in this paper. Their correlation is based on posi-
tion in the section and fossils other than brachiopods. (Dake, 1921, pp. 14-28;
Weller and St. Clair, 1928, pp. 91-104; for Dutchtown formation, see Cullison,
1938, pp. 219-228.)

Rock Levee formation.—This formation was proposed by Grohskopf (1948,
p. 360) for part of the limestones referred by Ulrich (1939, p. 109) to the
Murfreesboro formation in the vicinity of Cape Girardeau in Missouri. This
formation takes some thickness from the underlying Joachim and the over-
lying Plattin formations. Knowledge of this formation is derived from surface
exposures and a study of deep wells. The name is from a siding on the St. Louis—
San Francisco RR. in NW4NW4NW43 sec. 24, T. 30 N., R. 13 E., Cape
Giradeau County. In the type area the thickness in wells is 270 feet but only
about 50 feet appear on the outcrop at the junction of U. S. Highway 61 and
Missouri Highway 74. The formation contains an upper zone 70 feet thick char-
acterized by cystid plates; the remainder of the formation contains silt and sand
in the residues. The formation is composed mostly of buff and gray dolomitic
rock but the upper part is fine gray limestone. Fossils are not abundant, but
the upper layers contain Ancistrorhyncha nussouriensis Cooper. Correlation is
with the Peery limestone formation in the Appalachians because of similarity of
the Ancistrorhyncha occurring in the two formations.

PLATTIN GRouP.—The rocks to which this name is applied formerly had only
formational rank. Larson (1951, pp. 2041-2075) recently raised them to the
status of a group. Larson recognized four formations in ascending order:
Bloomsdale, Beckett, Hager, and Macy. The Plattin group is prominent in east-
ern Missouri from Scott County in the south to Ralls County at the north, and
westward to eastern Callaway County. The group thins to the north, and all
the member formations thin in the same direction. The maximum thickness is
about 300 feet; near Mineola in its western range only 31 feet of the lower beds
is exposed.

Bloomsdale formation.—This is composed mainly of calcilutite and fine-
grained dolomite with interbeds of oolite and limestone pebble conglomerate. At
its thickest, near Beckett Mills, Ste. Genevieve County, it is mostly 59 feet of
calcilutite but thins to about 12 feet at Kings Lake in Lincoln County. The forma-
tion is sparsely fossiliferous as usual in calcilutites and, as usual in that lithology,
Ancistrorhyncha (=A. costata Ulrich and Cooper) is common. hynchotrema

(probably Rostricellula) sp. is also reported. Correlation is suggested with the —

Wardell formation.

Beckett formation.—This is a fine-textured limestone with intraformational
calcarenite and carbonate pebble conglomerate. Chert is abundant in the upper
part. The lower Beckett is pinkish-brown, fucoidal, and fine-textured. This part
is absent north of Herculaneum, Jefferson County. The Upper Beckett contains

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PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 115

many layers of calcarenite, limestone pebble conglomerate, and brown chert
nodules. The formation attains a thickness of 108 feet in Cape Girardeau and
Perry' Counties but thins to 75 feet at Kings Lake. Twenty-eight feet is exposed
at Mineola, but there the Plattin has been eroded to this level. Few good col-
lections were taken by Larsen from this formation, but he reports Cryptophrag-
mus antiquatus (Raymond) among other fossils. Brachiopods listed are:

Ancistrorhyncha sp. O. cf. O. wagneri (Okulitch)

? Camerella sp. Opikina sp.

Campylorthis deflecta (Conrad) *Parastrophina hemiplicata (Hall)
Glyptorthis bellarugosa (Conrad) Rostricellula sp.

Opikina subtriangularis Wilson

Correlation is suggested with the Witten of the Appalachians and Platteville
of the upper Mississippi Valley.

Hager formation.—Generally fine-textured limestone named after Hager
School in Perry County. Three facies are recognizable: The major part is
slabby olive-gray limestone with buff-weathering partings; calcilutite and cal-
carenite make up the remainder. The first facies is mainly in the thicker sec-
tions on the south. The calcilutite generally overlies the slabby limestone and
both grade laterally into calcarenite. The formation is 85 to 93 feet thick in Cape
Girardeau County and thins out near the latitude of St. Louis. The slabby lime-
stone facies contains abundant fossils:

Campylorthis deflecta (Conrad) ? R,. minnesotensis (Sardeson)
*Glyptorthis bellarugosa (Conrad) ? Rostricellula sp.
*Hesperorthis tricenaria (Conrad) Strophomena cf. S. delicatula Fenton
*Opikina cf. O. transitionalis (Okulitch) S. dignata Fenton
*O. cf. O. wagneri (Okulitch) S. extgua Fenton

Opikina sp. S. plattinensis Fenton

Orbiculoidea sp. Strophomena sp.

Rostricellula cuneiformis (Fenton and Fenton) Zygospira recurvirostris (Hall)

Correlation of Hager formation.—Presence of Campylorthis is a link to the
Platteville limestone of the upper Mississippi Valley. The formation is also
linked to the Lebanon of the Central Basin of Tennessee by the Zygospira.

Macy formation.—Named after Macy in Ste. Genevieve County, Mo. The
formation is 87 feet thick at the type locality and is slightly thicker in Cape
Girardeau County. It thins to a little more than 4o feet in Lincoln County but
is absent in Callaway County to the west. The formation is mostly of fine-tex-
tured limestone divided into two members: Hook below and Zell above.

Hook member of Macy formation——This member is composed of fine, yel-
lowish-brown fucoidal limestone with irregular buff-weathering dolomitic part-
ings. The member is 13 to 15 feet thick near Kings Lake in Lincoln County, Mo.,
and thickens to 4o feet in Perry County. The following brachiopods are reported:
Campylorthis deflecta (Conrad)

Hesperorthis tricenaria (Conrad)
Opikina sp.

116 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Zell member of Macy formation.—This member is named from the town of
Zell, in Ste. Genevieve County, Mo., and consists of fine-textured limestone with
green shale partings. It is 32 feet thick at the type locality and contains nodular
and bedded brown chert. The member is 52 feet thick near Altenburg in Perry
County but thins to 29 feet at Kings Lake. It is 22 feet thick just west of
St. Louis. Fossils, including brachiopods, are abundant in the Zell:

Ancistrorhyncha sp. R. cf. R. missouriensis
Camerella bella Fenton (Fenton and Fenton)
C. gregeri Cooper R. plattinensis Fenton
Campylorthis deflecta (Conrad) = C. subplana Rostricellula sp.

Cooper Schigocrania filosa (Hall)
Doleroides gibbosus (Billings) Sowerbyella punctostriata (Mather)
D. cf. D. pervetus (Conrad) = D. missouriensis Strophomena auburnensis Fenton

Cooper S. delicatula Fenton

*Glyptorthis bellarugosa (Conrad) S. dignata Fenton
Hesperorthis tricenaria (Conrad) S. exigua Fenton
*Opikina septata ? Salmon S. inconsueta Fenton
*O. transitionalis (Okulitch) S. musculosa Fenton
Opikina sp. S. plattinensis Fenton
Pionodema subaequata (Conrad) S. winchelli Hall and Clarke
Protozyga rotunda Cooper Strophomena sp.
Rhynchotrema sp. Trematis foerstei Cooper
Rostricellula cuneiformis Zygospira recurvirostris (Hall)
(Fenton and Fenton) Z. variabilis Fenton

Correlation of Macy formation.—The combination of genera and species in
this formation indicates a correlation with the Carters limestone formation of
the Central Basin of Tennessee and with the Spechts Ferry member of the De-
corah formation. The Carters contains Camerella bella, Doleroides, Pionodema
subaequata, and Strophomena suggestive of S. auburnensis.

Barnhart formation.—This name is here proposed for the “Decorah” of
Missouri which overlies the Plattin group and underlies the Kimmswick forma-
tion. The type section is at Koch Valley School on U. S. Highway 61-67,
2 miles south of Barnhart, Kimmswick (15’) Quadrangle. Here the formation
consists of about 20 feet of greenish shale with interbedded thin limestones, all
abundantly fossiliferous. The following species were collected:

Campylorthis subplana Cooper R. missouriensis (Fenton and Fenton)
Hesperorthis tricenaria (Conrad) Sowerbyella sp.

Pionodema subaequata (Conrad) Strophomena delicatula Fenton
Protozyga rotunda Cooper S. dignata Fenton

P. superba Cooper Trematis foerstei Cooper
Rafinesquina sinclairi Salmon Zygospira sp.

Rostricellula cuneiformis (Fenton and Fenton) Z. lebanonensis Cooper

Correlation of Barnhart formation—Although the lower shaly part of this
formation was correlated with the Spechts Ferry member of the Decorah forma-
tion by Kay (1935, p. 288), the fossils collected by the writer from the lower
and upper parts indicate equivalence with the Guttenberg member of the De-
corah formation rather than the Spechts Ferry. This is indicated by the great
abundance of Pionodema, Rafinesquina, large Sowerbyella, and Zygospira, The
writer failed to find Doleroides in the few localities visited.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 117

Auburn chert.—Residual chert in Lincoln County, Mo., contains numerous
fossils listed by E. B. Branson (1909) and A. F. Foerste (1920). The brachio-
pods in the fauna are:

Dalmanella subaequata (Conrad) = Pionodema subaequata (Conrad)
D. testudinaria (Dalman) = Paucicrura rogata (Sardeson)
Hallina globularis Cooper

Idiospira panderi (Billings)

Lingula sp.

Orthis tricenaria Conrad = Hesperorthis tricenaria (Conrad)
Paucicrura rogata (Sardeson)

Strophomena incurvata (Shepard) = S. auburnensis Fenton
Rafinesquina minnesotensis (N. H. Winchell) = Opikina

R. sinclairi Salmon

Zygospira recurvirostris (Hall)

Z. nicolleti Winchell and Schuchert = Protozyga superba Cooper

Correlation of Auburn chert—lIt has been suggested that the Auburn chert
should be included in the Plattin group (Bradley, 1925, p. 66), but the brachio-
pods are not in accord with this suggestion from what is now known about the
Auburn fauna. The presence of Rafinesquina indicates a higher correlation. It
is here suggested that this formation may be chertified Decorah of Missouri=
Barnhart formation, rather than Plattin and that the correlation should be with
the Guttenberg member of the Decorah of the upper Mississippi Valley.

NORTHERN ARKANSAS

In the Eureka Springs, Harrison, and Yellville Quadrangles and adjacent
areas to the east, the Buffalo River group is well exhibited. The section here
from the bottom up is: Everton, Jasper, St. Peter, Joachim, and Plattin forma-
tions. As in the Missouri section, fossils are rare and brachiopods are not known
from the Buffalo River group except in the Everton-Jasper limestones.

Everton-Jasper formation.—According to McKnight (1935, p. 40) the
Jasper limestone has a maximum thickness of 50 feet and is indistinguishable
from denser phases of the Everton limestone below. The Jasper was originally
thought to be above the Joachim and St. Peter formations, but McKnight indi-
cates that these formations were incorrectly identified in the Eureka Springs—
Harrison Folio. The rocks so identified in reality are only parts of the Everton.
McKnight further states that according to present evidence the Jasper limestone
“interfingers with the dolomitic facies in the upper part of the Everton and
should be considered a member of the Everton.” The following brachiopod was
found in the Jasper at Pindall:

Onychoplecia matutina Cooper

Correlation of Everton-Jasper formation—The one species of brachiopod
(Onychoplecia matutina Cooper) known from the Everton-Jasper does not per-
mit a good correlation. However, the position below the St. Peter and the pres-
ence of Onychoplecia is a possible link with the Lenoir of the Appalachians.

Plattin formation.—This formation in the Yellville Quadrangle ranges from

118 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

a feather edge to 100 feet in thickness. It is mostly dense blue-gray limestone
often resembling lithographic limestone. The few brachiopods listed are:
Ancistrorhyncha costata Ulrich and Cooper Strophomena cf. incurvata (Shepard)

Camerella aff. C. panderi Billings Zygospira aff. Z. recurvirostris (Hall)
Rafinesquina aff. R. alternata (Emmons)

This is a short list, but the presence of Rafinesquina aff. R. alternata suggests
that part of this formation should be correlated with the Decorah-Barnhart rather
than all with the Plattin. It may be noted that in the Missouri occurrences of
Plattin true Rafinesquina is unknown, but this genus is abundant in the over-
lying Barnhart. In the Batesville region Ancistrorhyncha is common and is a
good indicator of the lower Plattin.

8. THE ARBUCKLE AND WICHITA MOUNTAINS, OKLAHOMA

The rocks of the Arbuckle and Wichita Mountain areas include an important
section of early Middle Ordovician strata known as the Simpson group. This
group consists of five formations, all of them originally proposed in charts or
correlation tables. The history of the nomenclature of the Simpson group is
discussed fully by Loeblich (1942, pp. 413-416) and need not be repeated here.
Detailed description of the formations was published by Decker and Merritt
(1931) and later elaborated by Decker (1941). As is usual with many for-
mations in the United States, stratigraphic information may be had in minute
detail, but the paleontology has never been well done. So it is with the Simpson
group. The only paleontology besides Loeblich’s (1942) description of the
Bryozoa of the upper Simpson is the faunal listing attempted by Decker (in
Decker and Merritt) in 1931. These lists are most unsatisfactory because they
contain numerous identifications of genera and species now known not to occur
anywhere in the Simpson sequence. In at least one instance Richmond species
have been identified in a formation that cannot be younger than the Porterfield
stage.

At present, and on the basis of Decker’s work (1941), five formations are
recognized in the Simpson group. Ulrich (1933) distinguished eight formations,
but three of them were not accepted by Decker. It seems best to follow Decker
in this matter at the present time, but it is possible that the future may see
further splitting within the group. The five formations recognized are, from the
base up: Joins, Oil Creek, McLish, Tulip Creek, and Bromide. Herein the
Bromide is divided into two members. Faunal affinities of the formations are
with the Appalachians and with the Great Basin. Like their geographic situa-
tion between the Appalachian and Great Basin areas, the faunas also indicate.
intermediate relationships to both realms.

Joins formation.—This formation consists of thin limestones and shales vary-
ing from 30 to 296 feet in thickness. It is limited to the middle southern and
western parts of the Arbuckles and the north end of the Criner Hills. The forma-
tion abounds in the brachiopod Desmorthis nevadensis, which was formerly re-
ferred to Orthis costalis Hall by earlier workers. Desmorthis costata Cooper is

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 119

a rare species. The Oklahoma specimens, however, do not seem to be related
to the New York species. Anomalorthis sp. occurs in the Joins also, This genus
thus indicates relationship to the Oil Creek formation which occurs just above
the Joins.

The occurrence of these two brachiopods in the Joins formation as well as in
the overlying Oil Creek formation is interesting in connection with other fossils
found in the Joins. The graptolite Didymograptus artus has been taken from a
shaly zone and indicates relationship to the D. bifidus zone which occurs at the
top of the Lower Ordovician (Canadian). On the basis of this graptolite, Decker
assigns the Joins to the high Canadian. Such an assignment leads to difficulties,
however, when the Joins is compared to the Pogonip sequence in Nevada.

The brachiopod Desmorthis characterizes certain beds in the Pogonip which
immediately overlie the Palliseria [Mitrospira| and Receptaculites zones several
hundred feet in thickness. These zones are not represented in the Arbuckle
sequence, consequently a disconformity of considerable magnitude occurs in
that area. These zones in Nevada contain fossils of post-Canadian aspects which
suggest that the Joins, despite Didymograptus artus, should be assigned to the
early Middle Ordovician.

Oil Creek formation.—This formation consists of sandstones, limestones,
and shales. The sandstones are more than 200 feet thick in the eastern part of
the mountains but thin to the west; the limestones thicken in the opposite
direction from 20 feet to more than 500 feet. Several species of brachiopods oc-
cur in the Oil Creek which have been incorrectly assigned to species from the
Chazy group. Two of them were referred to Clitambonites: C. multicosta and
C. porcia. The former is Anomalorthis oklahomensis Ulrich and Cooper, but
the latter is not yet redescribed. The other Chazy species identified are Orthis
acutiplicata and O. ignicula. The former is described herein as Orthambonites
dinorthoides, new species, and the other as O. subconvexus, new species. This
formation is correlated satisfactorily with the upper Pogonip, the part which
contains Pseudomera nevadensis, because this trilobite also occurs in the Oil
Creek formation. Lingulella sp. 2 is another Oil Creek brachiopod.

McLish formation.—This formation consists of limestone, sandstone, and
shale which reach a thickness of nearly 500 feet. Decker’s list of brachiopods
includes a number of obvious misidentifications :

Camarotoechia sp. = Ancistrorhyncha ? perplexa Cooper
Dorytreta bella Cooper
Glyptorthis sp. 4
Orthambonites minutus Cooper
*Orthis acutiplicata (Identification doubtful)
O. ignicula
*Plectambonites pisum
Ptychopleurella oklahomensis Cooper
*Rafinesquina champlainensis
Sphenotreta sulcata Cooper
*Strophomena incurvata
Valcourea strophomenoides ?
Zygospira recurvirostris = Dorytreta bella Cooper

I20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

This list includes Black River-Trenton species and some Chazyan species.
This formation is correlated with the Lenoir of the Southern Appalachians and
shares a number of species, aside from brachiopods, with it.

Tulip Creek formation.—This formation is best known in the western part
of the mountains and the Criner Hills. It consists chiefly of sandstone and shale
with minor amounts of limestone. The thickness varies between 190 and 380
feet. Not many brachiopods have been found in the formation. Decker reports:
Dalmanella sp., Dinorthis deflecta, and Pionodema sp. Neither the first nor the
last genus has yet been seen in the Simpson group. The middle species is obvi-
ously misidentified because that species is restricted to the Platteville formation
which is considerably younger than the Tulip Creek. The following brachiopods
were taken from this formation:

Atelelasma sulcatum Cooper Orthambonites minus Cooper
Hesperorthis matutina Cooper Plectorthis punctata Cooper
Mimella sp. 2 Valcourea deckeri Cooper
Murinella sp. 2 V. tennis Cooper

Correlation of Tulip Creek formation—Abundance and kind of Valcourea
suggest possible correlation with the Elway formation of Virginia and Tennessee.

Bromide formation.—This is the uppermost and most widespread of the
Simpson formations. As at present constituted, it consists of sandstone, shale,
and limestone, the latter predominating at least in the upper part. The forma-
tion is thickest at the west end of the Arbuckle Mountains where it measures
674 feet. The Bromide is divisible into two members: A lower shaly member
here called the Mountain Lake member of the Bromide formation, and a limy
member here called the Pooleville member.

Mountain Lake member of Bromide formation.—This name is suggested for
the fine sequence of lower Bromide nearly completely exposed along Spring
Creek on both sides of the line between secs. 8 and 17, T. 2 S., R. 1 W., Murray
County. The name is taken from Mountain Lake, E34 sec. 22, T. 2, S., R. 1 W.,
near Woodford, Okla., where the shores of the lake exhibit this shale. The lower
194 feet above the basal sandstone of the Bromide consists chiefly of shales with
some thin limestone beds. Between 25 and 46 feet above the saudstone the
brachiopod Sowerbyites is abundant in association with numerous massive bryo-
zoans. Above this zone Valcourea transversa is abundant. At the top of the
sequence and just under the light-colored nodular limestones of the Pooleville
member numerous brachiopods are associated with the cystids Platycystites and
Cheirocrinus. The uppermost beds contain the brachiopod Multicostella convexa
Cooper. This brachiopod zone affords a means of comparison with other sections
and gives a clue to the facies changes.

To the east, this member appears to become more limy and in places has de-
veloped bryozoan bioherms and calcarenite banks. Along Oklahoma Highway
99, about 3 miles south of Fittstown, a fine sequence contains the Valcourea
transversa zone. Here it occurs just above a thick calcarenite or lime sand. In
the section 1.8 miles south of Sulphur, along Oklahoma Highway 18, the Sower-

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 121

byites zone appears in the form of a bryozoan reef on the west side of the road.
The brown and purplish shales on the east side of the road contain the fauna
accompanying Multicostella convexa at the type section.

At Rock Crossing in the Criner Hills the Multicostella convexa zone occurs
just under the thin-bedded, light-colored limestones of the upper Bromide. The
section underlying the Multicostella zone here is composed mostly of green shales
and thin-bedded, brownish limestone.

Brachiopods from the Mountain Lake member are:

Acanthocrania erecta Cooper

A, subquadrata Cooper
Atelelasma oklahomense Cooper
Bellimurina compressa Cooper
B. subquadrata Cooper
Chaulistomella crassa Cooper
C. mira Cooper

C. mundula Cooper

C. nitens Cooper

C. obesa Cooper

Dactylogonia sculpturata Cooper
D, subaequicostellata Cooper
Doleroides compressus Cooper
Fascifera dalmanelloidea Cooper
Glyptorthis crenulata Cooper

G. obesa Cooper

G. uncinata Cooper
Hesperorthis crinerensis Cooper
Lingulella galba Cooper
Macrocoelia bella Cooper
Mimella extensa Cooper

M., subquadrata Cooper

Multicostella convexa Cooper
M. sulcata Cooper

Murinella partita Cooper
Onychoplecia tenuis Cooper
Opikina expatiata Cooper

O. gregaria Cooper

Oxoplecia filosa Cooper
Paurorthis macrodeltoidea Cooper
Petrocrania sp. 3

Philhedra sp. 1

Protozyga costata Cooper

P. elongata Cooper

P. magnicostata Cooper
Rostricellula cuneata Cooper
Skenidioides oklahomensis Cooper
Sowerbyella indistincta Cooper
S. plicatifera Cooper

S. vulgata Cooper

Sowerbyella sp. 1

Sowerbyites lamellosus Cooper
Valcourea transversa Cooper

Pooleville member of Bromide formation.—This name is proposed for the
upper limy beds which are quite uniform in lithology from place to place but
vary considerably in thickness. The name is taken from Pooleville on the west
side of the Arbuckle Mountains, but the type section is on Spring Creek above
the Mountain Lake member about on the line between secs. 8 and 17, T. 2 S.,
R. 1 W., Murray County. Here is mostly a light-gray to nearly white limestone,
thin bedded except for the top 15 feet which is massive and contains Receptacu-
lites. The member at the type section is about 250 feet thick. The lowest zone is
that of Strophomena oklahomensis, then follows a zone of Oxoplecia gouldi, a
zone of Doleroides oklahomensis. A zone with Ancistrorhyncha occurs near the
top. These zones are not present in all sections, and their thicknesses are different
in different sections. It is also clear from the variations of thickness in this part
of the column and the different zones that occur at the top of the section in
different places that the contact with the overlying Viola formation is an uncon-
formable one.

This is essentially the interval to which Ulrich applied the name Criner on
several of his charts. Ulrich, however, failed to define the formation and to desig-
nate a type section. It seems best, therefore, to use another name. Besides, the

I22 SMITHSONIAN MISCELLANEQUS COLLECTIONS VOL, 127

section on Spring Creek is a more complete and far superior one in every respect
to that in the Criner Hills.

Brachiopods are abundant and exquisitely preserved in most of the localities of
the Pooleville member. Decker’s list (Decker and Merritt, 1931, p. 48) is almost
wholly from the Pooleville member and is duplicated below with corrections and
additions by the writer:

Acanthocrania oklahomensis Cooper

A. subquadrata Cooper

Ancistrorhyncha costata Ulrich and Cooper

A. globularis Cooper

Camarella volborthi = Camerella anteroplicata Cooper

C. oklahomensis Cooper

Cliftonia gouldi = Oxoplecia gouldi Ulrich and Cooper

Cramia granulosa = Either or both of the species of Acanthocrania above
C. trentonensis = Petrocrania inflata Cooper

Craniops tenuis Cooper

Cyclospira parva Cooper

Dalmanella fertilis = ?

Dinorthis deflecta = ? Chaulistomella magna Schuchert and Cooper
D. subquadrata = Chaulistomella magna Schuchert and Cooper
Ectenoglossa ? sculpta Cooper

Glossella liumbona Cooper

Hebertella bellarugosa = Glyptorthis costellata Cooper

H., frankfortensis = ?
*Lingula coburgensis

L. cf. elegantula

L. eva

Lingulasma oklahomense Cooper

Lingulella ? glypta Cooper

Neostrophia gregaria Cooper

Onychoplecia tenuis Cooper

Opikina extensa Cooper

O. formosa Cooper

Opikina sp. 2

Orbiculoidea cf. lamellosa= O. eximia Cooper

Orthis tricenaria = Hesperorthis sulcata Cooper

Pachyglossa biconvexa Cooper

Paurorthis macrodeltoidea Cooper

Pionodema cf. subaequata = Doleroides oklahomensis Cooper
Plaesiomys sp. = ?

Platymena ? bellatula Cooper

Plectambonites sericeus

Plectambonites sp. (small) = ?

Plectoglossa oklahomensis Cooper

Plectorthis symmetrica Cooper

Pseudolingula imperfecta Cooper
*Rafinesquina alternata (incorrect identification, genus not seen by writer)
Rafinesquina minnesotensis = Opikina
*R. winchesterensis = ? This is a Trenton species from Kentucky misidentified.
Rhynchotrema minnesotense = Rostricellula transversa Cooper
Rostricellula sp. 1

Scenidium anthonense = Skenidioides perfectus Cooper

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER I23

Schizambon dodgei= S. perspinosum Cooper
Sowerbyella variabilis Cooper

Sowerbyites hami Cooper

S. lamellosus Cooper

Strophomena incurvata = S. costellata Cooper
S. oklahomensis Cooper

S. cf. planumbona = S. crinerensis Cooper
*S. trentonensis

Zygospira nicolleti = Protozyga loeblichi Cooper

Correlation of Bromide formation.—The Bromide has been variously placed
from the Chazyan to the Trenton (Loeblich, 1942, p. 413-416). Decker’s (1952)
final pronouncement was correlation with the lower Trenton. Loeblich (1942,
p. 417) states that “The evidence presented by the bryozoa suggests a lower
Trenton age, and the fauna is closely allied to the Decorah of Minnesota.” The
brachiopod evidence does not support this conclusion. This is, however, not the
first instance in which age determination of the same formation based on differ-
ent types of fossils is not in agreement. In considering the age of the Bromide
from the brachiopod evidence, it is desirable to evaluate the brachiopods from
the two divisions of the Bromide described above.

The brachiopods occurring in the lower Mountain Lake member with its reefy
beds include Atelelasma, Multicostella, Mimella, Sowerbyites, and Valcourea.
These are genera that occur together in the Appalachian sequences in formations
underlying the Benbolt formation. They are common particularly in the Lincoln-
shire and Hogskin formations. The presence of Fascifera and Opikina suggest
somewhat higher beds because the former has not been taken in the two Appa-
lachian formations referred to below the Ward Cove. Conspicuously absent from
the lower part of the Mountain Lake member is Strophomena, which becomes
abundant in the Appalachians in beds above the Benbolt formation, particularly
in the Wardell formation. The best correlation of the lower Mountain Lake is
with the Lincolnshire.

Upper Mountain Lake abounds in cystids, Platycystites and Cheirocrinus, with
abundance of Sowerbyella, Chaulistomella, and Glyptorthis. Also present are
Fascifera and Doleroides. Correlation with the Benbolt is suggested.

Significant brachiopods occurring in the upper or light-colored Pooleville
member are: Strophomena, Doleroides, Craniops, Campylorthis, and Ancistro-
rhyncha. These genera characterize beds in the Appalachians and the Central
Basin that overlie the Benbolt. The association, except for Craniops, appears
first in the Wardell formation of the Appalachians and in the Ridley limestone of
the Central Basin of Tennessee. The correlations thus suggested indicate that
Bromide sediments spanned a time similar to the sediments of the Appalachians
between, but including the Lincolnshire and the Wardell.

Viola formation.—Information on this formation is now relevant to the dis-
cussion of brachiopods forming the subject of this monograph because of Decker’s
(1952) recent correlations of the Athens shale of Virginia with part of the Viola
limestone of Oklahoma. The report of Nemagraptus in the Viola is quite dis-

124 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

turbing because it leads to a correlation that is in distinct conflict with that indi-
cated by other groups of animals.

The Viola limestone is commonly a light-gray to dark-buff limestone, but it
may be nearly white with scattered brown blotches. The limestone is usually
tough, fine-grained, but some coarsely crystalline beds occur in it. At Rock
Crossing in the Criner Hills a shaly zone occurs at the base, but a similar shaly
zone occurs elsewhere 100 to 150 feet above the base. The limestone is mostly
thin bedded in layers 2 to 6 inches thick. The formation, minus the Upper Ordo-
vician (Fernvale), attains a thickness of 165 to 880 feet.

The Viola formation has been dated as spanning the time of Trenton to Rich-
mond sedimentation. The Upper Ordovician has been separated as the Fernvale
formation. The only part of the Viola of immediate concern in this discussion is
the lower part and that of the shales. Brachiopods reported from the lower mem-
ber of the Viola according to Decker (1933, p. 1414) are:

*Dalmanella hamburgensis *Rafinesquina deltoidea
Dinorthis pectinella *Rhychotrema increbescens
Paterula polita Cooper *Strophomena filitexta
Platystrophia sp. *Zygospira recurvirostris

*Plectambomites sericeus

Examination of this list will at once disclose that some of the names are prob-
ably incorrect. The combination of species does not exist anywhere else and
seems impossible from what is known of Trenton faunas elsewhere. The list,
however, is sufficiently accurate to show that the assemblage belongs above the
lower Trenton. The presence of Dinorthis pectinella suggests the Ion member
of the Decorah formation, but the reported presence of Platystrophia makes
further complications. This genus does not appear below the Trenton as far as
present knowledge goes. Furthermore, it is not known in low Trenton but char-
acterizes Hull in New York and Ontario and the Prosser in the upper Mississippi
Valley.

On the basis of brachiopods, therefore, the lower Viola would be placed at the
lowest with about middle Trenton. Decker (1952, p. 100) makes the same age
assignment for the Viola. Inconsistent with this age, however, is Decker’s (1952,
p. 101) reported discovery of the Nemagraptus fauna in the lower part of the
Viola. The occurrence of the trilobite Robergia in the Viola and its presence in
the “Athens” (Liberty Hall) led Decker to correlate these two divisions of rock.
It might be suggested here that an inconsistency exists with the trilobite and
perhaps also with the graptolite. In the Appalachians the Nemagraptus fauna is
the midgraptolite zone of the Athens at the Athens type locality, as in other parts
of the Appalachians. It has been shown above that type Athens is equivalent to
the Arline formation. In Catawba Valley the Nemagraptus fauna occurs 300 feet
above Botetourt—Effna formations which are equivalent to part of the Arline.
Now the Arline fauna is many hundreds of feet below the Oranda or overlying
Salona faunas, which are the only ones in the Appalachian Valley that could be
correlated with the lower Viola brachiopods listed above. Thus Nemagraptus in
the Appalachians is definitely below Oranda—Salona faunas. However, the

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 125

Oranda is undoubtedly a derivative of the Arline whose black shale equivalent,
if any existed, might conceivably have included a Nemagraptus derivative in the
higher position. Possibly this is the case with Nemagraptus in the Viola—it is
a holdover or recurrent Nemagraptus fauna equivalent to a middle Trenton
brachiopod fauna. If this supposition should prove to be true, our views regard-
ing the infallibility of graptolite correlation will be severely shaken.

Womble (Stringtown) formation of Arkansas and Oklahoma.—A thick
sequence of dark shales occurs in the Ouachita geosyncline in Arkansas and ad-
jacent Oklahoma. This is the Womble (Stringtown in Oklahoma) shale which
contains the Nemagraptus graptolite assemblage and is said (Decker 1952, pp.
96-100) to be equivalent to the “Athens” of Virginia. Two brachiopods, Archae-
orthis biconvexa Cooper, new species, and Paterula subcircularis Cooper, were
taken from this shale in Oklahoma.

g. THE BLACK HILLS, SOUTH DAKOTA

Whitewood formation.—This formation as exposed just northeast of Dead-
wood, S. Dak., consists of three members. The lowest member overlies the
Scolithus sandstone of the Upper Cambrian Deadwood formation and consists of
gray fissile shale containing scolecodonts and a few other fragmentary fossils.
Above the shale occurs a coarse-grained, soft, light-gray siltstone which contains
conodonts and remains of other types of fossils. The siltstone is transitional to
the overlying dolomite member of the Whitewood formation which contains fos-
sils of probable upper Devonian age.

The shale and siltstone members are said by Furnish, Barragy, and Miller
(1936) to be of medial Ordovician age. The scolecodont fauna of the shale indi-
cates a correlation with the Spechts Ferry member of the Decorah formation.
The siltstone contains the following brachiopods:

Crania ?

Dalmanella ? cf. D. hamburgensis (Winchell, not Walcott) = Dalmanella winchelli Cooper
Lingula sp.

Rafinesquina sp.

Rhynchotrema cf. R. minnesotense (Sardeson)

Sowerbyella sp.

Strophomena sp.
Zygospira

This list of brachiopods and species of conodonts indicates a low Trenton
(Rockland) age for the siltstone.

I0. THE GREAT BASIN—NEVADA AND CALIFORNIA

The Ordovician of the Great Basin region in Nevada and California has never
been described in detail, and actually very little is known about it. In some areas
rocks comprising the Pogonip group or formation have been assigned to the
Chazy and some to the Black River and Trenton, but the faunas are nearly un-
known. After two short visits to southern and central Nevada the writer is able

126 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

to give a brief statement on the major divisions of the early Middle Ordovician
in the Antelope Valley west of Eureka, Nev., and in the range fronting French-
man Flat about 45 miles northwest of Las Vegas, Nev. Although I have seen
and collected from all the rocks mentioned herein, I am indebted to Drs. Edwin
Kirk and C. W. Merriam, of the U. S. Geological Survey, for information as to
localities and for the use of their collections.

ANTELOPE VALLEY AND TOQUIMA RANGE

Between the top of the Canadian and the base of the Upper Ordovician, in the
region between Eureka and the Antelope Valley, occurs a remarkable thicken-
ing of the sequence to the west. Examination of both sides of Antelope Valley
and the east side of the Toquima Range, 25 miles west of the Antelope Range,
is necessary to build a composite section. Even after this is done the complete
section has never been ascertained, and some uncertainty exists as to sequence.

In ascending order the following divisions were recognized :

Poconip Group: With Orthidiella zone, Pallaseria (formerly Muitrospira)
zone, Desmorthis zone, Anomalorthis zone, Rhysostrophia zone ; EUREKA GROUP:
With a lower 25-foot sandstone, yellow limestone with Sowerbyites, dark shale
with Reuschella, and upper or Eureka quartzite. All the zones below the lower
sandstone have hitherto been placed in the Upper Pogonip limestone, a term
that has for many years outlived its usefulness.

Poconrp Group: Orthidiella zone.—Lowest zone of the sequence character-
ized by the small brachiopod Orthidiella. Specimens abundant, often silicified.
In Whiterock Canyon, Roberts Mountains Quadrangle, the limestone of the zone
rests on green shale thought to be the same as that at the top of the Canadian.
The Orthidiella zone is better developed and replete with fossils in the first ridge
east of Frenchman Flat on the Las Vegas, Nev., Quadrangle. Here 150 feet of
heavy-bedded limestone underlies the Palliseria (Mitrospira) beds. Most of the
brachiopods listed below were taken from the Frenchman Flat locality, but many
of them were seen also in Whiterock Canyon.

Idiostrophia nuda Cooper O. longwelli Ulrich and Cooper

Ingria cloudi Ulrich and Cooper Orthidiella sp. 1

Liricamera nevadensis Cooper Porambonites sp. 3

Orthambonites eucharis (Ulrich and Cooper) Trematorthis masoni Ulrich and Cooper
Orthidiella carinata Ulrich and Cooper T. robusta Cooper

O. costellata Cooper T. tenuis Cooper

O. extensa Ulrich and Cooper

Correlation—At present few of the genera listed above have been certainly
identified in any North American deposits other than those of Nevada. Brachio-
pods suggesting Orthidiella occur in the Table Head series of Newfoundland.
Trematorthis lévisensis Ulrich and Cooper is known from the limestone No. 2
boulder bed of the Lévis shale. This suggests a younger age for this bed than
hitherto suspected.

Pallaseria (Mitrospira) zone.—Consists of a great thickness of heavy-
bedded limestone abounding in the snail that gives the zone its name, and also

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 127

in large Maclurites which are suggestive of those of the Chazy group of the
Champlain Valley, N. Y. The upper part of the zone is characterized by abun-
dance of Receptaculites. No brachiopods have been described from this zone.

Rhysostrophia sp. 1

Desmorthis zone.—This zone overlies the Receptaculites beds of the Pal-
laseria (Mitrospira) zone. The bed is well displayed under the Eureka quart-
zite on the west and south sides of Lone Mountain about 18 miles west-northwest
of Eureka, Nev. It consists of dark, moderately heavy-bedded limestone con-
taining Desmorthis nevadensis Ulrich and Cooper in abundance and often ex-
quisitely silicified. In addition, Anomalorthis nevadensis Ulrich and Cooper
and A. lonensis (Walcott) occur. Hesperonomiella minor (Walcott) is a less
well known species.

Correlation—Abundant Desmorthis and Anomalorthis signify correlation of
this part of the ““Pogonip” with the Joins formation of Oklahoma.

Anomalorthis zone.—Under this heading are placed thin-bedded limestones
abounding in sponges described by Bassler (1941), abundant Pseudomera and
other peculiar trilobites, together with Anomalorthis and a few other brachiopods,
as follows:

Aporthophyla typa Ulrich and Cooper Orthambonites minusculus (Phleger)

Idiostrophia paucicostata Cooper Porambonites sp. 1
Lingulella sp. 1

Correlation.—Presence of the trilobite Pseudomera and the brachiopod Ano-
malorthis indicate correlation with the Oil Creek formation of Oklahoma.

Rhysostrophia zone.—Consists of thin-bedded limestone abounding in fos-
sils. Some of the brachiopods are silicified, while others occur in a silicious
matrix which permits dissolving the shell away from the rock to produce impres-
sions of the interior. The following species are known:

Goniotrema perplexum Ulrich and Cooper Rhysostrophia nevadensis Ulrich and Cooper
Hesperomena leptellinoidea Cooper R. occidentalis Ulrich and Cooper
Leptellina occidentalis Ulrich and Cooper Sowerbyella rugosa Ulrich and Cooper
Orthambonites bifurcatus Cooper Syndielasma biseptatum Cooper

O. occidentalis Cooper Taphrodonta parallela Cooper

O. paucicostatus (Ulrich and Cooper) Toquimia kirki Ulrich and Cooper
Orthidium bellulum Ulrich and Cooper Valcourea intracarinata Ulrich and Cooper

Porambonites ? umbonatus Cooper

Correlation.—This is a difficult fauna to place, but it has obvious affinities with
the Table Head Series of Newfoundland and some of the boulders of the Mystic
conglomerate. Rhysostrophia occurs in both of the formations named and so
does Orthidium. The latter genus also links these beds to the limestone No. 2
of Lévis, Quebec. The Newfoundland faunas are still too little known to make
any close comparisons. Another genus common to the Table Head and Rhyso-
strophia zone is Porambonites.

EuREKA GROUP: Lower 25-foot sandstone.—On Martins Ridge, west side
of Antelope Valley, northeast of the Martin Ranch, the Pogonip is overlain by

128 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

a 25-foot bed of brown sandstone containing a few cephalopods. This bed is
thought by some (Kirk, 1933.) to be the lower part of the Eureka sandstone. In
Lone Mountain, 18 miles north-northwest of Eureka, the main body of the White
Eureka sandstone is thought to rest on the “lower sandstone,” but in Martins
Ridge some 350 feet of limestone and shale intervene between the two sandstones.

Yellow limestone.—Overlying the “lower sandstone” occurs about 150 feet
of thin-bedded, yellow-weathering limestone abounding in fossils. Generally the
specimens are not well preserved, and they are not silicified. One of the abundant
genera is Sowerbyites. The species identified from this bed are:

Camerella umbonata Cooper Multicostella parallela Cooper
Camerella sp. 3 M. rectangulata Cooper
Eoplectodonta alternata (Butts) Oxoplecia monitorensis Cooper
Isophragma ponderosum Cooper Sowerbyella sp. 4

Lingulasma occidentale Cooper Sowerbyites lamellosus Cooper
Macrocoelia occidentalis Cooper Valcourea plana Cooper

Correlation—The brachiopods listed suggest a correlation with the Arline
formation of the Southern Appalachians. The relationship is best shown by the
presence of Isophragma, which has not been seen outside of this horizon and the
lower part of the Benbolt formation. The presence of Sowerbyites is not an
anomaly because that genus ranges from the Lincolnshire to the level of the
Bromide (approximately Ridley-Wardell). The Macrocoelia is also in accord
with the suggested correlation. The zone in question cannot be lower than Lin-
colnshire or higher than Benbolt, with the balance in favor of the Arline-Effna
level.

Dark shale with Reuschella.—Overlying the yellow-weathering limestone
are dark shales, about 150 feet in thickness, abounding in brachiopods and other
fossils reminding one most strongly of the Oranda formation of Virginia. Here
occur :

Bilobia hemispherica Cooper Oxoplecia nevadensis Cooper
Bimuria sp. I Paurorthis gigantea Cooper
Cristiferina cristifera Cooper Plectorthis obesa Cooper
Eoplectodonta alternata (Butts) Reuschella vespertina Cooper
Glyptorthis sp. 1 Rostricellula angulata Cooper
Hesperorthis antelopensis Cooper Sowerbyella merriami Coopet
Leptaena ordovicica Cooper Sowerbyella sp. 1 and 2
Leptellina incompta Cooper Strophomena sp. 1

Correlation —The Reuschella, Bilobia, Leptaena, and Eoplectodonta are links
to the Oranda formation. This is corroborated by the presence of the trilobite
Cryptolithus. The other genera are all more or less common in the Virginia
formation.

Eureka quartzite.—The main mass of the Eureka, sparkling quartzite, white
and heavy-bedded, overlies the dark shales. It underlies the Hanson Creek for-
mation of probable Maquoketa age. This fixes the level of the Eureka as probably
middle or high Trenton.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 129

PIOCHE DISTRICT, NEVADA

The Tank Hill formation is named from Tank Hill in the Ely Springs
Range west of Pioche, Nev. The formation also appears at the north end of
the Bristol Range. It consists of 450 feet of gray thin-bedded limestone, con-
glomeratic in the lower part. The upper 50 feet is shaly limestone with abundant
fossils. Brachiopods are:

Hesperinia kirki Cooper
Orthambonites sp.

CALIFORNIA

Phleger (1933, p. 2) proposed the Mazourka and Barrell Spring formations
for Ordovician rocks exposed in the Inyo Range, east-central California.
Mazourka formation.—This formation consists of argillaceous shales and
limestones 675 feet thick. Fossils are not well preserved, but several brachiopods
were collected and some new species described, as follows:
Crania sp.
Orthis minusculus Phleger = Orthambonites minusculus (Phleger )
Plectorthis mazourkaensis Phleger

P. patula (Phleger)
Triplesia sp. = syntrophoid

Besides the brachiopods listed, interesting trilobites were collected indicating
correlation of these beds with the Oil Creek of Oklahoma and the Anomalorthis
zone of the Pogonip. These trilobites are Pseudomera barrandei (Billings),
Encrinurus hastula Phleger, and E. octonarius Phleger, the latter two being
referable to the genus Ectenonotus which occurs in the East in the Table Head
series and Mystic boulders.

Barrel Spring formation.—This formation was also proposed by Phleger
(1933, p. 5) for 130 feet of quartzites, impure limestones, and argillaceous shales.
Three brachiopods are listed:

*Orthis tricenaria Conrad = Hesperorthis ?

O. decipiens Phleger = Hesperorthis ? decipiens (Phleger)
Plectambonites angulatus Phleger = Valcourea angulata (Phleger)

The identification of Orthis tricenaria Conrad is almost certainly a mistake,
but the identification may indicate some other species of Hesperorthis. Although
the description of Plectambonites angulatus states that the ‘Pedicle valve [is]
evenly convex, but gently arched along the median line from beak to front,” the
figure of the one cotype illustrated gives the impression that the specimen is
really nearly flat or gently concave. Furthermore, the long slits representing the
pits formed by the dental plates in the impression and the muscle scars suggest
Valcourea rather than Plectambonites. The latter name is undoubtedly used in
the old sense and would now be called Sowerbyella, inasmuch as true Plectambo-
nites is at present unknown on this continent.

The lithology and the few fossils known from the Barrel Spring formation

I30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

suggest correlation with the lower yellow beds overlying the 25-foot quartzite
in Martins Ridge on the east side of the Monitor Range.

II. FORMATIONS IN UTAH

Pogonip equivalents of post-Canadian age occur in Utah where sections and
brachiopods have been described.

IBEX AREA, UTAH

Hintze (1951) has split the Pogonip of western Utah, Millard County, into
six formations in ascending order: House limestone, Fillmore limestone, Wah-
wah limestone, Juab limestone, Kanosh shale, and Lehman formation. The for-
mations below the Wahwah limestone have few brachiopods, but the top of the
formation is characterized by a bed 1 foot thick abounding in Hesperonomiella
minor (Walcott). The Juab limestone contains Orthambonites subalatus (UI-
rich and Cooper). The Kanosh shale is characterized by Orthambonites michaelis
(Clark) and Anomalorthis utahensis Ulrich and Cooper. Kirkina millardensis
Salmon is reported from the top of the Kanosh shale and the overlying Lehman
formation. The Kanosh shale thus seems to be the equivalent of the Oil Creek
of Oklahoma and the Anomalorthis zone in Neveda. These names do not appear
on the chart.

NORTHEASTERN UTAH

Swan Peak quartzite.—This formation contains the brachiopods Orthambo-
nites subalatus (Ulrich and Cooper), O. michaelis (Clark), O. swanensis (UI-
rich and Cooper), Anomalorthis utahensis Ulrich and Cooper, A. lonensis (Wal-
cott), Syntrophopsis utahensis Ulrich and Cooper, and Westonia ? elongata
Walcott. The presence of Anomalorthis suggests correlation with the Oil Creek
of Oklahoma and the Anomalorthis zone in Nevada.

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SECTION [It [THE PUootlo
GENERAL DISCUSSION OF THE FOSSILS

After the appearance of the publication on Ozarkian and Canadian Brachio-
poda, to which the present monograph is a sequel, brachiopod studies were con-
siderably retarded by World War II. Nevertheless, some important ideas have
been expressed. One of these has to do with the naming of the valves of brachio-
pods. Hitherto the valves have been known as ventral and dorsal, but the work
of Percival (1944) makes mandatory a return to the more cumbersome terms
“pedicle” and “brachial,” + which are used throughout this monograph.

CONCEPT OF FAMILY AND GENUS

The same principles that guided Ulrich and Cooper in the preparation of the
Ozarkian and Canadian Brachiopoda are used in the present monograph. The
basis for uniting genera into families is again basically the pattern of the cardi-
nalia combined with some constant features of the pedicle valve. Genera are
then based on minor details of the interior deviating from the normal family
pattern and the nature of the ornamentation and exterior form of the valves.
Specific characters are found in minor details of the ornamentation and differ-
ences in exterior form.

SHELL STRUCTURE

The writer has used shell structure as a guide in classification, but it is far
too early to propose the nature of the shell as a basis of classification. Too much
has to be learned about shell structure before it will have real value in defining
major divisions. The arrangement of convenience used in the Shimer-Shrock
“North American Index Fossils” (1944) has been misconstrued by some as a
scheme of classification. It was not so proposed; the arrangement was designed
to help the student separate brachiopods into easily recognized small groups in
order to make identification easier.

In the present work the shells are again divided for convenience into groups
based on shell structure. In the endopunctate shells the genera and families are
probably well grouped, but with the impunctate and pseudopunctate forms some
difficulties are still to be mastered. For example, the orthoid genus Anomalorthis
appears to have scattered pseudopunctae ; it is also well known through the work
of Opik (1934) on the clitambonitids that some of these genera are pseudopunc-
tate while others are without pseudopunctae. These difficulties cannot be re-
solved in this monograph because much of the material does not permit detailed

1In a recent note Percival discards his views of 1944 and indicates that the orientation of
Terebratella inconspicua agrees with that of Tegulorhynchia and the pedicle valve is ventral
in orientation.

131

132 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

knowledge of the shell structure, and furthermore the problem is one that con-
cerns all the brachiopods and not just those of the early Middle Ordovician.

NOTES ON EVOLUTION

The time in which the brachiopods here described lived is not a long one geo-
logically speaking, yet considerable change took place in brachiopod evolution.
During this time the appearance and rise of several major groups, as far as now
known, took place, namely, the dalmanellids, rhynchonellids, and spiriferoids.
In addition this time saw the heyday of the plectambonitids. Among the Gastro-
caulia, Cambrian types still lingered on, but the group as a whole had already
lost ground to the Pygocaulia except in a few limited habitats.

Gastrocaulia.—Perhaps the most interesting feature connected with the in-
articulate brachiopods is the persistence into the Middle Ordovician of genera
that definitely have Cambrian affinities. This is strikingly seen in the genus Dic-
tyonites which is structurally a member of the Dictyoninacea, new superfamily,
a specialized group of early brachiopods. This group at present defies classifica-
tion in either Neotremata or Atremata, because there is no pedicle foramen, nor
is there a pedicle groove as in the linguloids.

The appearance of Lingula in the Ordovician has been stated as a fact, yet
the writer does not use that name for any of the linguloids described herein.
The etched linguloids from Pratt Ferry make it clear that, on hinge structures
at least, the linguloids of the part of the Ordovician covered by this monograph
are varied and some of them have the definite characters of Lingulella. It can-
not now be said that Lingula did not exist in the Middle Ordovician, but the
specimens that could be prepared, and the apical structures revealed, all proved
to have other affinities. For this reason the name Lingulella was preferred to
Lingula for species whose apical structures could not be revealed.

The limestone of the Pratt Ferry formation in particular and bituminous lime-
stones associated with black shales in general yielded many specimens of the
conical Acrotretacea. These showed more variety than has hitherto been re-
vealed in the Middle Ordovician. The genus Conotreta is obviously related to
the Cambrian shells now called Homotreta and others like them, but the Ordo-
vician genera seem to have more elaborate pallial markings than those from the
Cambrian. The bizarre interior of Ephippelasma is still not understood, but it
is here suggested that the saddle-shaped plate of the brachial valve is probably
a lophophore support.

Lingulasma is a giant form of linguloid characterized by elevated muscle plat-
forms. The genus seems to be totally unrelated to the Trimerellidae but may
have affinities with Lingulops.

The early trimerellid genus Obolellina is characterized by the modest develop-
ment of the muscle platforms which become highly elevated in the Silurian mem-
bers of the superfamily.

The genus Schizambon is of interest because it is a spiny genus that appeared
in the earliest Ordovician and persisted into late Middle Ordovician. The mem-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 133

bers of this genus available for study have been examined with great care, but
no basis was found for generic separation anywhere along the line.

The Craniidae appear in this part of the Ordovician well formed except for
two possible genera and proved to be fairly common in places. The cemented
habit seems to have been well established. Eoconulus is a small cone that is
abundant in the suite of formations at the base of the rocks deposited in the
Porterfield stage. Only brachial valves that have a primitive musculature are
known. These are not postulated as the forerunners of the Craniacea because
Acanthocrania, a more standard genus, occurs with them.

A form of uncertain relationships, Undiferina, possibly was a cementing
brachiopod. The median septum and general form of the one known valve sug-
gest relationship to Conotreta and allies rather than to the Craniacea. It is pos-
sible that the Acrotretacea may have developed a cemented form, but this is not
yet positively known.

The insoluble residues from the Pratt Ferry limestone yielded a number of
forms of which single valves only are known. Perhaps the most peculiar among
these is the brachiopod here called Trematis ? spinosa, which at present is known
only from the brachial valve. This valve contains a tuft of spines on the hinge
area. The purpose of these spines cannot at present even be conjectured. Spines
such as these on the opposite valve might have been used for attachment in early
stages as they are in the Productacea, but attachment spines on a brachial valve
are at present unknown. The Pratt Ferry residues have opened the door only
a slight crack but have permitted a fleeting glance at the form and habits of a
wonderful world of inarticulate brachiopods. Much of significance and interest
to morphology and classification is yet to come from these shells that have been
thought to be retarded in evolution and diversification.

Pygocaulia.—This monograph contains many new articulate genera that have
been revealed by extensive collecting and also by the acid treatment of limestones.
The Pratt Ferry limestone has produced some of the most unusual forms. The
Effna-Rich Valley limestone, Botetourt formation, and Arline formation, all be-
longing to a related suite of beds which are likewise related to the Pratt Ferry
formation, have yielded other odd genera. The result is that some families have
become unexpectedly large and much has been learned about hitherto poorly
known brachiopods.

The Table Head series and upper Pogonip group have yielded their share of
unclassifiable material. These formations form a sort of bridge between the
Lower Ordovician (Canadian) rocks and those laid down in the Marmor stage.
They have produced brachiopods that are intermediate in their structure between
the Canadian ones and the higher genera. An example is Syndielasma which
is prophetic of Sowerbyella but differs in not having the cardinalia welded to-
gether as in the later genera. Hesperomena is a more primitive leptellinoid than
the higher ones as it does not have the visceral disk elevated. The Table Head
brachiopod fauna gives indications of containing numerous genera that will plug
gaps in the developmental stages of the families of the Middle Ordovician brachi-
opods when it is fully studied.

134 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

OrTHIDAE.—The members of this family are fairly abundant but show few
remarkable features. It is interesting to note that many of the species have strong
resemblances to European forms. One of the interesting European types is
Productorthis which is represented by two species, both of which, as true Ameri-
can representatives, far outstrip in size any of the known European species. The
American species are not exactly like the European ones, especially in the cardi-
nal process, but the exterior is similar.

HESPERORTHIDAE.—This family is represented by numerous species of the
genus Hesperorthis and, in places, hosts of Glyptorthis.

DINoRTHIDAE.—This family had its probable origin and culmination in the
time spanned by this monograph. The earliest genera are Valcourea and Multi-
costella. The latter, which lacks a pseudodeltidium, is probably the more advanced
form. The last of the American multicostellate Dinorthidae except Plaesiomys
appear in the Lebanon and Carters formations. There they are strongly con-
vexi-concave and without a pseudodeltidium. The origin of the family is uncer-
tain, but it may have been derived from Hesperonomia as suggested by Ulrich
and Cooper (1938, p. 20).

PLECTORTHIDAE.—The earliest member of this family appears as Desmorthis
in the Joins and Pogonip formations of the Whiterock stage. The genus is short
ranged but may have developed into Plectorthis in the time represented by Tulip
Creek sedimentation. Plectorthis has a long range into the Upper Ordovician.
In general the older species of Plectorthis are more finely ribbed than those of
the higher formations and the Upper Ordovician. Mimella is an abundant Mar-
mor form which extends into the Dryden and Wardell but then gives way to Dole-
roides which is the probable forerunner of Heberiella. No origination stock for
the Plectorthids can now be postulated other than the Finkelnburgiidae as indi-
cated by Ulrich and Cooper (1938, p. 18).

SKENIDIIDAE.—This group appears in the formations deposited in Marmor
time, and some of its members are fairly long ranged. Skenidioides appears in
Porterfield time and extends into the Silurian. In this family, too, are placed a
smooth to plicate form of skenidioid which has modified cardinalia, Tropidothyris.
Scaphorthis and Phragmorthis are also placed within the family. These are char-
acterized by cruralia and the latter by an enormous median septum. Scaphorthis
has the profile and ornamentation suggesting a dalmanelloid, but the shell is
definitely impunctate. Origin of these shells is obscure indeed, and they may
not be a natural group as now placed.

TRITOECHIIDAE.—This family is represented by the unusual genus Eremo-
toechia that is essentially a strongly biconvex Tritoechia having the external
appearance of Mimella. In spite of appearances the genus has the apically per-
forated pseudodeltidium (the foramen is smaller than in Tritoechia) and cardi-
nalia of the Ordovician (Canadian) genus. The few specimens in the collection
do not show development of a pseudospondylium such as that often exhibited by
Tritoechia. No other shells related to this one were seen, and this may be the
end of the stock.

CLITAMBONITIDAE.—This family is represented by Atelelasma which is spe-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 135

cialized to the extent that it has lost the pseudodeltidium. The stock is an ancient
one, first appearing in rocks laid down in Marmor time, and extends into the
late Porterfield stage.

KULLERVOIDAE.—This family is represented by a few specimens only of the
genus Kullervo. Pseudopunctae, which are a family character, were not seen in
the American shells.

CAMERELLIDAE.—After the Whiterock stage, members of the Syntrophiacea
are rare or absent, but the Camerellidae take their place and are often very
abundant. The group reaches its zenith in the rocks deposited from Whiterock
to Wilderness time. After that time the group declines. Certain trends may
be detected in some genera. Plectocamara is especially noteworthy for the reduc-
tion of the median septum of the brachial valve. Brevicamera, which forms a
family by itself, is noteworthy because of its sessile cruralium, the only genus to
achieve such a structure. The variety of exteriors and shapes exhibited by mem-
bers of the Camerellidae may ultimately permit further separation of genera. The
camerellids are structurally like syntrophids and probably arose from them, but
the change from a spondylium simplex in the latter group to a spondylium
duplex of the Camerellidae cannot be explained.

PARALLELELASMATIDAE.—This family belongs to the Pentameracea and is
characterized by having two long, subparallel septa in the brachial valve which
enclose the muscle scars. The family is represented by three genera unlike in
appearance but close internally. Parallelelasma occurs in the Pratt Ferry forma-
tion and is the earliest known pentamerid. Although it is an early form, it is
nevertheless a very complicated shell in its articulation at both ends of the valves.
The webbed costae at the front are a novel strainer device. The source of this
unusual group was not detected in the early Middle Ordovician; it must be
sought in Whiterock or earlier faunas.

RHYNCHONELLACEA.—One of the important events that took place in the time
spanned by this monograph is the arrival of the rhynchonellids. These appear in
the form of Rostricellula and Ancistrorhyncha. The former is the earlier, but
it is the more complicated shell of the two. Rostricellula has the standard rhyn-
chonellid complement of a cruralium (or septalium), hinge plate, and strong
median septum in the brachial valve, and dental plates in the pedicle valve.
Ancistrorhyncha, on the other hand, has complicated crura, a divided hinge plate,
but no median septum. This is probably an advanced form which cannot be an-
cestral to the rhynchonellids. The same is true of Rostricellula which is an early
but specialized type. The ancestor of the group must be looked for in rocks de-
posited in Whiterock time or earlier. Several small shells, such as Oligorhynchia,
Dorytreta, and Sphenotreta, appear to be rhynchonellids. These are probably
primitive forms in that they have a fold on the pedicle valve, which is an early
character. They are, however, specialized forms, too, in their complicated orna-
mentation, especially Oligorhynchia.

ATRYPACEA and SpiIRIFERACEA.—The advent of the calcified lophophore, as
far as now known, took place within the time embraced by this monograph. The
shells are all small and are generally rare in the earlier formations. The first

136 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

spire bearer is a small undescribed form from the Row Park formation of Mary-
land and a probably contemporaneous one, possibly the same species, from the
Crown Point formation of New York. Only single specimens are known in each
instance ; consequently, the interior is not known. Both of these are Protozyga-
like shells. This seems to be the most primitive of the genera. The spire has only
one volution. This genus, however, is fairly long ranged and becomes fairly
large in the late members of the genus in the Trenton group. No originating
form can now be postulated.

Idiospira and Cyclospira have more complicated spires. The former suggests
affinities with Atrypa and allies in which the spire is coiled toward the brachial
valve. In the latter the spiral coils are directed inward. Cyclospira and Zygospira
may have arisen from Protozyga. The same origin is possible for /diospira.

PLECTAMBONITACEA.—The present study shows the members of this super-
family to be numerous, extensively distributed, and diverse in structure. In North
America the first of these appear in rocks deposited during late Canadian time,
and a fairly large development took place in Whiterock time and culminated in
the Porterfield stage. Three major stocks can be recognized: The palaeostro-
phomenoids, probably originated from Aporthophyla, the leptellinoids, and the
sowerbyelloids ; the origin of the last two is obscure. The first group is well rep-
resented in Europe as well as America. The group also is commonest in rocks
deposited during Porterfield time. Distinctive genera are Apatomorpha, Palae-
ostrophomena, Glyptambonites, and Sowerbyites, which have similar growth
forms to the Strophomenidae. These genera are characterized by having a single
septum in the brachial valve. The sowerbyelloids have two or more septa and
form a prolific group that appears in the Whiterock stage and continues on into
the Silurian. This group may have come from Syndielasma or some still more
primitive pseudopunctate shell such as Pelonomia. The leptellinoids are charac-
terized by a visceral disk and strong median septum. They appear in the late
Canadian with Leptella and become moderately common in the early part of the
Middle Ordovician. They continue into the Silurian but are generally rare fos-
sils at that time. It is not possible to say what the derivation of the Plectam-
bonitids is, but the most likely ultimate origin is from an orthid stock sometime
in the early Ordovician or late Cambrian. Cymbithyris Cooper (1952), a con-
cavo-convex billingsellid of the late Cambrian, is a possibility.

STROPHOMENIDAE.—It has been shown that the resupinate and normally con-
vex forms of this division are closely related. The resupination of the shells
seems not to be a valid means of classification (A. Williams, 1953). The genera
of this subfamily probably originated in some orthoid stock in the early Ordovi-
cian, possibly from some form like Taffia or Aporthophyla. Kirkina is the oldest
known form in this group having a lobate cardinal process. At any rate it ap-
pears in the Marmor stage as Macrocoelia and rapidly becomes more diverse.
Species of Strophomena and Opikina are the commonest shells in certain parts
of the country in rocks deposited during the Wilderness stage.

LEPTAENIDAE.—This division seems to have originated with Hesperinia in the
high Pogonip, deposited during the Whiterock stage. At any rate this genus has

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 137
i

a bilobed cardinal process necessary to produce the leptaenoids. The family re-

tained its pedicle opening through all the time embraced by this monograph.

DALMANELLACEA.—The earliest known punctate brachiopod on this continent
is Paurorthis, which is found in rocks formed during the Ashby stage. The genus
has some features that relate it to the Orthidae, such as the form of the vascula
media and the nature of the brachiophores. It seems difficult, however, to derive
other punctate forms from this one.

Several other punctate stocks appear simultaneously in the Porterfield stage:
Cyclomyonia, Paucicrura, and Laticrura. The first-named has the structure of
Pionodema and the Schizophoriidae. It seems to form a satisfactory originating
point for that family, but the stock from which Cyclomyonia itself came cannot
be conjectured. Paucicrura may have been derived from Paurorthts. This seems
possible, but it cannot be accepted with assurance. With Paucicrura came the
large family of Onniellidae which has a greater development in Europe than in
America. Laticrura parallels Scaphorthis in its cardinalia, and no progenitor is
known for it. The Heterorthidae appear to have had their origin outside of
America, possibly in the Llandeilo of Great Britain. Elasmothyris appears to be
a complicated punctate brachiopod but is probably out of the main line.

VOL. 127

SMITHSONIAN MISCELLANEOUS COLLECTIONS

138

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VOL. 127

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VOL. 127

SMITHSONIAN MISCELLANEOUS COLLECTIONS

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PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Acanthambonia minutissima
Cooper
A. virginiensis Cooper

Acanthocrania cumberlandensis
(Foerste )

A. erecta Cooper

A. grandis Cooper
A. granulosa (N. H. Winchell)

A. oklahomensis Cooper
A. setigera (Hall)
A. spinosa Cooper

A. subquadrata Cooper

Acanthocrania sp. 1

Acrotreta gemma Billings
A. magna Cooper

Ancistrorhyncha australis
(Foerste)
A. costata Ulrich and Cooper

A. crassa Cooper
A. globularis Cooper

A. missouriensis Cooper
A, ? perplexa Cooper
A. ? vacua Cooper

Anisopleurella inaequistriata
Cooper
A. tricostellata Cooper

Anomalorthis lonensis
(Walcott)

SPECIES
Stage Formation
Porterfield Pratt Ferry
Porterfield Botetourt ?
Wilderness Wells
Porterfield Bromide
(Mountain Lake)
Porterfield Benbolt
Wilderness- Decorah
Trenton
Wilderness Bromide
(Pooleville)
Wilderness- Platteville
Trenton Decorah
Porterfield Edinburg
(Liberty Hall)
Porterfield Bromide
(Mountain Lake)
(Pooleville)
Wilderness Lebanon
Whiterock Table Head
Whiterock Boulders of
Mystic cgl.
Wilderness Lebanon, Camp
Nelson, Nealmont
Wilderness Dryden, Ridley,
Wardell, Hostler,
Bromide, Pamelia,
Plattin
Wilderness Peery, Hostler,
Wardell, Dryden
Wilderness Bromide
(Pooleville)
Porterfield Rock Levee
Marmor McLish
Marmor Mingan
Porterfield Whitesburg,
Chatham Hill
Porterfield Pratt Ferry
Whiterock Upper Pogonip,

Swan Peak

Geographic
location

Ala.

Okla.

Wis. and Minn.

Va.

Okla.

Tenn.

Newfoundland
Quebec

Tenn., Pa.

Tenn, Va.,
Pa Ark:
Okla yY.,
Mo., Ga.

Tenn.

Okla.

Mo.

Okla.

St. Lawrence

River,
Quebec

Tenn., Va.

Ala.

Nev., Utah

147

Page
212

213

284
284

284
285

285
285
285

286

286
246
246
620

621

623
624
624

625
625

805

806

392

148 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
A. nevadensis Ulrich and
Cooper

A. oklahomensis Ulrich and
Cooper
A, utahensis Ulrich and Cooper

Apatomorpha pulchella
(Raymond)

Archaeorthis biconvexa Cooper

Atelelasma decorticatum
Cooper

A. dorsoconvexum Cooper
A. holstoni (Hall and Clarke)

A. ? multicostum (Hudson)
A, obscurum Cooper

A. oklahomense Cooper
A. perfectum Cooper

A. planum Cooper
A. plaiys Cooper

A. sulcatum Cooper
A. variabile Cooper
Atelelesma sp. 1
Atelelesma sp. 2

Bellimurina charlottae
(Winchell and Schuchert)
B. compressa Cooper

B. concentrica Cooper
B. parviplicifera Cooper
B. subquadrata Cooper

B. sulcata Cooper
B.sp.1
B.sp.2

SPECIES
Stage Formation
Whiterock Upper Pogonip,
(Anomalorthis
zone)
Whiterock Oil Creek
Whiterock Swan Peak,
Kanosh,
Upper Pogonip
Porterfield Athens
Porterfield Womble
Ashby Murat, Lincoln-
shire, Whistle
Creek?
Porterfield Athens
Ashby or Lincolnshire
Porterfield (Hogskin), or
Arline
Marmor Crown Point
Ashby Lincolnshire
(Hogskin)
Porterfield Bromide
(Mountain Lake)
Porterfield Arline, Whistle
Creek?
Porterfield Benbolt
Ashby Lincolnshire
(Hogskin)
Ashby Tulip Creek
Marmor Lenoir
Porterfield Little Oak
Porterfield Botetourt
Wilderness Decorah
(Guttenberg )
Porterfield Bromide
(Mountain Lake)
Porterfield Pierce
Wilderness Lebanon
Wilderness Bromide
(Mountain Lake)
Porterfield Pratt Ferry
Porterfield Benbolt ?
Wilderness Wardell

Geographic
location

Nev.

Okla.

Utah, Nev.

Tenn.

Okla.

Va., Tenn.

Tenn.
Tenn.

Naya. Vis
Tenn.

Okla.
Tenn., Va.

Tenn.
Tenn.

Okla.
Tenn.
Ala.
Va.

Minn.
Okla.

Tenn.
Tenn.
Okla.

Ala.
Va.
Va.

VOL. 127

Page
392

392

393

709

293

518

859

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Bilobia hemisphaerica Cooper

B. piswm (Ruedemann)

B. virginiensis Cooper

Bimuria buttsi Cooper
B. immatura Cooper

B. lamellosa (Bassler)
B. ? matutina Cooper

B. parvula Cooper

B. siphonata Cooper
B. superba Ulrich and Cooper

Bimuria sp. 1

Brevicamera camerata Cooper

Camerella anteroplicata Cooper
C. bella Fenton

C. bicostata Cooper

C. breviplicata Billings

C. costellata Cooper
C. edmundsoni Cooper

C. elliptica Cooper

C. globularis Cooper

C. gregeri Cooper

C. immatura Cooper

C. indefinita Cooper

C. ? leiorhynchoidea Cooper

SPECIES

Stage
Wilderness

Wilderness or
Porterfield

Porterfield

Porterfield
Porterfield

Wilderness
Whiterock

Porterfield

Porterfield
Porterfield

Wilderness

Porterfield

Porterfield
Wilderness
Ashby

Whiterock

Ashby
Porterfield

Ashby
Ashby
Wilderness
Porterfield
Ashby
Wilderness ?

Formation
Oranda, Rodman,
dark shale of
Eureka group,

Salona
Boulder in
Rysedorf cgl.
Edinburg (Cyrt.-
Nid. zone),
Shippensburg,
Botetourt

Little Oak

Botetourt, Effna-
Rich Valley

Oranda

Boulders in
Mystic cgl.

Shippensburg,
Chatham Hill,
Edinburg (Cyrt.
zone), Liberty
Hall

Pratt Ferry

Botetourt, Effna,
Arline, Tellico

Dark shale, under
Eureka quartzite

Pratt Ferry

Bromide
(Pooleville)
Carters, Plattin

(Macy )
Lincolnshire
(Hogskin)
Boulder in
Mystic cgl.
Elway
Poteet
(Yellow Branch)
Lincolnshire
Whistle Creek
Plattin (Macy)
Chatham Hill
Elway
Edinburg
(Liberty Hall)

Geographic

location

Vai) -Pa., Nev,

N.Y.

Va., Md., Pa.

Ala.
Va.

PasevVia:
Quebec

123. Wel

Ala.

Va., Tenn.

Nev.

Ala.

Okla.

Tenn., Mo.

Tenn.

Quebec

Tenn., Va.

Va.

Va.
Va.
Mo.
Va.
Tenn.
Va.

149

Page
760

150 SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 127

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
C. minuta Cooper

C. multiplicata Cooper
C. nuda Cooper

C. obesa Cooper

C. oklahomensis Cooper

C. parva Billings

C. pennsylvanica Cooper

C. perplexa Cooper

C. plicata (Schuchert and
Cooper )

C. polita Billings

C. ? primigenia (Bradley)
C. pulchra Cooper

C. quadriplicata (Willard)
C. tennesseensis Cooper

C. triangulata Cooper

C. twmida Cooper
C. umbonata Cooper

C. unicostata Cooper
C. varians Billings

C. ventricosa Cooper
C. volborthi Billings
Camerella sp. I
Camerella sp. 2
Camerella sp. 3

Camerella sp. 4

Campylorthis deflecta (Conrad)

C. subplana Ulrich and Cooper

Chaulistomella brevis (Willard)

C. crassa Cooper

SPECIES
Stage Formation
Porterfield Botetourt, Effna,
Chatham Hill
Ashby Elway
Porterfield Murfreesboro
Wilderness Rockland
Wilderness Bromide
(Pooleville)
Whiterock Table Head (N, P)
Marmor Row Park
Ashby Elway
Wilderness Ridley, Wardell
Whiterock Boulders in
Mystic cgl.
Trenton Kimmswick
Wilderness Ridley
Ashby Lincolnshire
(Hogskin)
Porterfield Arline
Marmor Lenoir
Whiterock Table Head
Ashby Yellow ls. on 25’
ss. at base of
Eureka group
Porterfield Ward Cove
Marmor Mingan, Crown
Point
Marmor Crown Point
Wilderness Cloche Island,
Rockland
Porterfield Benbolt
Marmor Blackford
Ashby Yellow ls. on 25’
ss. at base of
Eureka group
Porterfield Whitesburg
Wilderness Platteville
(McGregor )
Wilderness Plattin (Macy),
Barnhart
Porterfield Benbolt, Dryden,
Sevier
Porterfield Bromide

(Mountain Lake)

Geographic
location

Newfoundland
ipa

Tenn., Va.
Tenn.

Quebec

Mo., Ark.
Tenn.
Tenn.

Tenn.

Tenn.
Newfoundland
Nev.

Tenn.

St. Lawrence
River,
Quebec,
Nee

Ney:

Ontario,
Manitoulin

Tenn.

Va.

Nev.

Tenn.

Wis., Minn.,
Ill.

Page
571
572
573
574
574

575

577

578

579

434

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
C. elongata (Willard)
C. inaequistriata Cooper
C. lebanonensis Cooper

C. magna (Schuchert and
Cooper )
C. mira Cooper

C. mundula Cooper
C. nitens Cooper
C. obesa Cooper

C. rectangulata Cooper
C. ridleyensis Cooper
C. superlata Cooper
Chaulistomella sp. 1
Chaulistomella ? sp. 2

Chonetoidea virginica Cooper

Christiania auriculata Cooper
C. platys Cooper

C. subquadrata (Hall)

C. trentonensis Ruedemann

Colaptomena leptostrophoidea
Cooper

Conotreta ? alta Cooper
C. ? altirostra Cooper
C. apicalis Cooper

C. ? concentrica Cooper
C. cuspidata Cooper

C. depressa Cooper

SPECIES
Stage Formation
Porterfield Benbolt, Dryden
Wilderness Wardell, Dryden
Wilderness Carters, Lebanon,
Camp Nelson,
Cane Creek
Wilderness Bromide
(Pooleville)
Porterfield Bromide
(Mountain Lake)
Porterfield Bromide
(Mountain Lake)
Porterfield Bromide
(Mountain Lake)
Porterfield Bromide
(Mountain Lake)
Wilderness Wardell
Wilderness Ridley
Wilderness Ridley
Wilderness Carters
Wilderness Oranda
Porter field- Edinburg
Wilderness (Liberty Hall)
Wilderness Oranda
Porterfield Edinburg
(Nidulites and
Cyrtonotella
zones )
Porterfield Little Oak

Porterfield or
Wilderness

Trenton

Porterfield
Porterfield
Porterfield
Porterfield
Porterfield
Porterfield

“Lenoir,” Arline,
Athens, Botetourt
Effna, Edinburg
(Cyrt. & Nid.
zones), Pratt
Ferry, Young-
man, Rich Valley

Rysedorf

Martinsburg
(Salona)

Arline
Botetourt
Pratt Ferry
Pratt Ferry
Effna

Pratt Ferry

Geographic
location

Tenn.

Tenn., Va.

Ala., Ky.,
Tenn.

Okla.
Okla.
Okla.
Okla.
Okla.
Tenn.
Tenn.
Ga.

Ala.
Va.

Wire

Va.
Va.

Tenn., Ala.,
Va., Vt.

I51

Page
435
435
437

438
439
440
441
441
442
443
444
445
445

804

860
861

862

865

890

248
248
249
250
250
251

152 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
C. gigantea Cooper
C. magna Cooper
C. multisinuata Cooper

C. plana Cooper
C. rusti Walcott
C. triangulata Cooper

Craniops attenuata Cooper

C. minor (Winchell and
Schuchert)

C. tenuis Cooper

C. trentonensis (Hall)
Craspedelia marginata Cooper

Cristiferina cristata Cooper

C. cristifera Cooper

Cyclomyonia peculiaris Cooper

Cyclospira bisulcata (Emmons )
C. ? longa Cooper

C. parva Cooper
C. preciosa Cooper
C. quadrata Cooper

C. sulcata Cooper

Cyphomena angulata Cooper

C. grandis Cooper

C. homostriata (Butts)
C. ? radialis (Okulitch)

SPECIES
Stage Formation
Porterfield Pratt Ferry
Porterfield Whitesburg
Porterfield Botetourt, Pratt
Ferry, Whites-
burg, Chatham
Hill, Edinburg
(Liberty Hall)
Porterfield Effna
Trenton Trenton, Salona
Porterfield Effna
Wilderness Carters
Wilderness- Decorah to
Trenton Prosser
Wilderness Bromide
(Pooleville)
(Mountain Lake)
Wilderness Nealmont
Porterfield Pratt Ferry
Porterfield Chatham Hill,
Edinburg
Wilderness Oranda,
under Eureka
Porterfield Pratt Ferry
Trenton Coburg
Wilderness or Pebble in
Porterfield Rysedorf cgl.
Wilderness Bromide
(Pooleville)
Wilderness Edinburg
(Lantz Mills)
Wilderness Edinburg
(Liberty Hall)
Wilderness Sevier, Chatham
Hill
Porterfield Edinburg
(Cyrt.-Nid. zone)
(Liberty Hall),
Shippensburg
Trenton Martinsburg
(Salona)
Wilderness Oranda
Wilderness Chaumont

VOL. 127
Geographic

location Page
Ala. 251
Tenn. 252
Ala., Tenn., 253

Va.

Va. 254
NY We Pa. 254
Va. 254
Ala. 240
Minn. 240
Okla. 240
Pa: 241
Ala. 773
Va. 962
Va., Nev. 963
Ala. 975
N. Y 603
N. Y 693
Okla. 604
Va. 604
Va. 695
Tenn., Va. 606
Md., Va., Pa. 841
Va. 842
VayiPa. 843
Quebec 844

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

Cyrtonotella bella (Schuchert
and Cooper )

C. crassicostella (Schuchert and
Cooper)

C. fasciculata Cooper

C. grandistriata (Willard)

C. magna Cooper

C. minor Cooper

C. subplana Cooper

C. subquadrata Cooper
C. virginiensis Butts
Cyrtonotella ? sp. 1

Dactylogonia alternata Cooper
D. concentrica Cooper

D. extensa Cooper

D. geniculata Ulrich and Cooper

D. incrassata (Hall)
D. magna Cooper

D. magnifica Cooper
D. marmorata Cooper
D. obsoleta (Butts)
D. obtusa Cooper

D. palustris (Willard)
D. parva Cooper

D. prona (Willard)
D. sculpturata Cooper

D. strasburgensis Cooper

D. subaequicostellata Cooper

D. transversa Cooper

Dactylogonia sp. 1
Dactylogonia sp. 2
Dactylogomia sp. 3
Dactylogonia sp. 4
Dactylogonia sp. 5

SPECIES
Stage Formation
Ashby Lincolnshire
(Hogskin)
Porterfield Benbolt
Porterfield Benbolt
Porterfield Botetourt, Effna
Porterfield Sevier
Ashby Lincolnshire
Porterfield Edinburg
(Cyrtonotella
zone)
Porterfield Benbolt
Porterfield Arline, Botetourt
Porterfield Botetourt
Marmor Lenoir, Tumbez
Ashby Lincolnshire
(Hogskin)
Marmor Mingan
Porterfield Arline, Little Oak
Marmor Crown Point
Ashby Lincolnshire
(Hogskin)
Porterfield Ward Cove
Ashby Murat
Porterfield Little Oak
Ashby- Lincolnshire,
Porterfield Arline
Porterfield Farragut
Ashby Lincolnshire
(Hogskin)
Ashby Lincolnshire
Porterfield Bromide
(Mountain Lake)
Porterfield Edinburg
(Cyrtonotella
zone)
Porterfield Bromide
(Mountain Lake)
Porterfield Botetourt
Porterfield Benbolt
Porterfield Botetourt
Porterfield Benbolt
Porterfield Sevier
Porterfield Effna

Geographic
location

Tenn.
Tenn.

Va.
Va.
Tenn.
Tenn.
Va.

Va.
Va., Tenn.
Va.

Tenn., Va.
Tenn.

St. Lawrence

River,
Quebec
Tenn., Va.,

Ala.
ING Vit
Tenn.

Tenn.

Va.

Ala.
Tenn., Va.

Tenn.
Tenn.

Va.
Okla.

153

834

835

836

836

837
838
838
838
838

154 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Dactylogonia sp. 6
Dactylogonia sp. 7
Dactylogonia sp. 8

Dalmanella costellata Cooper
D. crassicostellata Cooper
D. rara Cooper

D. sculpta Cooper

D. sulcata Cooper
D. winchelli Cooper

Desmorthis costata Cooper
D. nevadensis Ulrich and
Cooper

Dictyonites perforata Cooper

Didymelasma abruptum Cooper
D. longicrurum Cooper

Dinorthis atavoides Willard
D. holdeni (Willard)

D. interstriata Willard
D. sweeneyi (N. H. Winchell)

D. tenuis Cooper
D. transversa Willard

D. transversoides Cooper

D. venusta Cooper
D. virginiensis Cooper

D. willardi Cooper

Diorthelasma parvum Cooper

Doleroides compressus Cooper

D. crassus Cooper
D. extensus Cooper

SPECIES
Stage Formation
Porterfield Probably Benbolt
Ashby Whistle Creek
Porterfield Poteet
(Yellow Branch)
Wilderness Oranda
Trenton Hermitage
Trenton Curdsville
Trenton Martinsburg
(Salona)
Trenton Hermitage
Wilderness Decorah
(Guttenberg)
Whiterock Joins
Whiterock Upper Pogonip,
Joins
Porterfield Pratt Ferry
Wilderness Rockland
Wilderness Lebanon
Ashby Lincolnshire
Ashby Elway,
Whistle Creek
Porterfield- Trenton, Benbolt
Trenton
Trenton Decorah (Ion)
Porterfield Sevier, Tellico
Porterfield Benbolt, Sevier,

Porterfield to
Wilderness

Porterfield
Wilderness ?

Ashby

Porterfield

Porterfield

Wilderness
Wilderness

Shippensburg,
Chota, Edinburg
(lower)

Dryden

Red Knobs

Edinburg,
Lantz Mills

Lincolnshire
(Hogskin)

Pratt Ferry

Bromide

(Mountain Lake)
Ridley
Ridley

VOL. 127
Geographic

location Page
Tenn. ° 839
Va. 8390
Va. 840
Va. 948
Tenn. 949
Tenn., Va. 949
Va. 950
Tenn. 951
Minn. 053
Okla. 446
Nev., Okla. 447
Ala. 188
Ontario 616
Tenn. 617
Tenn., Va. 303
Tenn., Va. 305
Nos Vaz 306
Iowa, Minn. 307
Tenn. 307
Md., Pa., 308

Tenn., Va.

Tenn. 400
Tenn. 401
Va. 402
Tenn. 402
Ala. 998
Okla. 456
Ga. 457
Ga. 457

PART I

CHAZYAN AND RELATED BRACHIOPODS—-COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
D. gibbosus (Billings)
D. irregularis Cooper
D. missouriensis Cooper
D. oklahomensis Cooper
D. ottawanus Wilson
D. pervetus (Conrad)

D. ? ponderosus Cooper
D. regularis Cooper

D. tennesseensis Cooper
D. winchelli Cooper

Doleroides sp. 1

Dorytreta bella Cooper
D. ovata Cooper
D. ? reversa Cooper

Drepanorhyncha ambigua
(Hall)
D. ottawaensis (Billings)

Ectenoglossa ? lyelli Billings

E. nympha (Billings)
E. nymphoidea Cooper

E. ? rubra Cooper
E. ? sculpta Cooper

Ectenoglossa sp.1

Eichwaldia subtrigonalis
Billings

Elasmothyris conctnnula
Cooper

SPECIES
Stage Formation

Wilderness Decorah
(Spechts Ferry),
Plattin (Macy)

Porterfield- Dryden

Wilderness

Wilderness Plattin (Macy),
Zell

Wilderness Bromide
(Pooleville)

Wilderness Chaumont,
Platteville

Wilderness Platteville
(McGregor)

Porterfield Botetourt, Effna

Wilderness Wardell, Pierce,
Dryden

Wilderness Carters, Lebanon,
Cane Creek

Wilderness Decorah
(Spechts Ferry)

Wilderness Pierce

Marmor McLish

Marmor Lenoir

Ashby Lincolnshire
(Hogskin)

Trenton Hull

Wilderness Rockland

Marmor Aylmer
(Rockcliffe)

Whiterock Table Head

Porterfield Whitesburg,
Paperville,
Chatham Hill,
Liberty Hall

Wilderness Bays

Wilderness Bromide
(Pooleville)

Whiterock Table Head

Wilderness Rockland

Porterfield Pratt Ferry

Geographic
location

Minn., N. Y.,

Ontario,
Mo.
Tenn.
Mo.

Okla.

Ontario, Wis.

Ill., Wis.

Was
Tenn., Va.

Ala., Tenn.,

IN: YY.

Ontario

Ontario

Newfoundland

Tenn., Va.

Tenn.
Okla.

Newfoundland

Ontario

Ala.

155

Page
458
459
460
461
462
462

463
464

465
466
467
667

667
668

627
628
217

218
218

219
220

220

947

985

156

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL.

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Elliptoglossa ovalis (Bassler )

E. rotundata Cooper

E. sylvanica Cooper

Eoconulus rectangulatus
Cooper

Eoplectodonta alternata
(Butts)

E. ? dubia Cooper

E. foerstei Cooper
E. ? triradiata (Butts)
Eoplectodonta sp. t

Ephippelasma minutum Cooper

Eremotoechia alabamensis
Cooper

E. cloudi Cooper

E. silicica Cooper

Eremotrema biconvexum
Cooper

Eridorthis inex pecta Cooper

Fascifera convexa Cooper

F. dalmanelloidea Cooper

F, stonensis (Safford)

SPECIES
Stage Formation
Porterfield Whitesburg,
to Trenton Oranda,
Botetourt,
Pratt Ferry,
Martinsburg,
Edinburg
Porterfield- Edinburg
Wilderness (Liberty Hall)
Upper Ord. Maquoketa
(Sylvan),
Maquoketa
Porterfield Pratt Ferry
Ashby- Oranda,
Trenton Eureka group,
Martinsburg
(Salona),
Salona
Porterfield Botetourt,
Edinburg
(Cyrt. zone)
Wilderness Wells
Wilderness Oranda
Porterfield or Edinburg
Wilderness
Porterfield Pratt Ferry
Porterfield Little Oak
Porterfield Arline
Porterfield Pratt Ferry,
Arline
Porterfield Benbolt
Porterfield Effna, Edinburg
(Liberty Hall)
Porterfield Benbolt
Porterfield Bromide
(Mountain Lake)
Wilderness Pierce, Dryden,

Wardell, Ridley,
Benbolt

Geographic
location

Ala., Md., Pa.,
Tenn., Va.

Ala.

Pa., Va., Nev.

127

Page
242

244

244

283

808

Iool

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
F, subcarinata Ulrich and
Cooper
F. sulcata Cooper
Fascifera sp. I

Furcitella plicata Cooper
F. scofieldt (Winchell and
Schuchert)

Glossella liumbona Cooper

G. papillosa Cooper
Glossella sp. 1

Glyptambonites glyptus Cooper

G. musculosus Cooper
G. ? platys (Butts)

Glyptoglossa cavellosa Cooper

Glyptoglossa sp. 1

Glyptomena ? bella Cooper

G. ? distans (Raymond)

G. ? minganensis (Twenhofel
and Stiles)

G. parvula Cooper

G. ? prisca (Raymond)
G. sculpturata Cooper
Glyptomena sp. 1

Glyptorthis alta Cooper
G. assimilis Cooper

G. bellarugosa (Conrad)
G. bellatula Cooper

G. concinnula Cooper

G. costellata Cooper

G. crenulata Cooper

SPECIES
Stage Formation
Wilderness Dryden, Ooltewah,
Wardell, Ridley
Wilderness Carters
Porterfield Ward Cove
Wilderness Oranda
Trenton Prosser
Wilderness Bromide
(Pooleville)
Porterfield Pratt Ferry
Porterfield Botetourt
Porterfield Effna,
Liberty Hall,
Pratt Ferry,
Rich Valley
Wilderness Oranda
Porterfield Edinburg
(Cyrtonotella
zone)
Porterfield Shippensburg
(Pinesburg)
Porterfield Effna,
Chatham Hill
Ashby Murat
Marmor Crown Point
Marmor Mingan
Porterfield Effna-Rich Valley
Marmor Crown Point
Porterfield Chatham Hill
Porterfield Ward Cove?
Trenton Kimmswick
Wilderness Ridley
Trenton? Decorah (Ion?)
Porterfield Chatham Hill
Porterfield Little Oak,
Arline
Wilderness Bromide
(Pooleville)
Porterfield Bromide

(Mountain Lake)

4

Geographic
location

Ga., Tenn., Va.

Tenn.
Va., Tenn.

Va.
Minn.

Okla.

Ala.
Va.

Va., Ala.

Va.

Ney:

St. Lawrence
River,
Quebec

Va.

INESY-;, Vit:

Va.

Va.

Mo.

Tenn.

Iowa, Wis.

Va.

Ala., Tenn.,
Va.

Okla.

Okla.

157

228

158 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
G. equiconvexa Cooper

G. glypta Cooper
G. irregularis Cooper

G. multicostellata Cooper
G. obesa Cooper

G. rara Cooper
G. senecta Cooper

G. subcarinata Cooper
G. subcircularis Cooper
G. sulcata Cooper

G. transversa Cooper
G. uncinata Cooper

G. untformis Cooper
G. untplicata Cooper
G. virginica Cooper
Glyptorthis sp. 1

Glyptorthis sp. 2

Glyptorthis sp. 3
Glyptorthis sp. 4

Goniotrema perpleaum Ulrich
and Cooper

Hallina globularis Cooper

H. lirata Cooper

H. saffordi Winchell and
Schuchert

Hesperinia kirki Cooper

Hesperomena leptellinoidea
Cooper
Hesperonomiella minor

(Walcott)

H. quebecensts Cooper

SPECIES
Stage Formation
Porterfield Botetourt,
Shippensburg
(Pinesburg)
Porterfield Effna, Rich Valley,
Pratt Ferry
Wilderness Pierce, Wardell,
Lebanon
Wilderness Ridley
Porterfield Bromide
(Mountain Lake)
Porterfield Benbolt
Porterfield Poteet
(Yellow Branch)
Porterfield Sevier
Trenton Decorah (Ion)
Marmor Crown Point
Marmor St. Martin
Porterfield Bromide
(Mountain Lake)
Porterfield Benbolt, Sevier
Porterfield Benbolt
Wilderness Wardell
Wilderness Dark shale under
Eureka quartzite
Ashby Lincolnshire
(Hogskin)
Porterfield Little Oak
Marmor McLish
Whiterock Upper Pogonip
Wilderness Auburn
Wilderness Benner-Stover
Wilderness Lebanon
Whiterock Tank Hill
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Whiterock Upper Pogonip
(Desmorthis
zone), Wahwah
Whiterock Boulder in

Mystic cgl.

VOL. 127
Geographic

location Page
Md., Va. 368
Va, Ala 360
Tenn. 370
Ga. 371
Okla. 372
Wee 372
Va. 373
Tenn. 374
Minn., Iowa 374
NEY 375
Quebec 376
Okla. 377
Tenn., Va. 378
Va. 379
Va. 379
Nev. 381
Tenn. 382
Ala. 382
Okla. 383
Nev. 711
Mo. 689
Pa 6890
Tenn. 690
Nev. 822
Nev. 745
Nev., Utah 337
Quebec 337

PART I

CHAZYAN AND RELATED BRACHIOPODS—-COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Hesperorthis antelopensis
Cooper
H. australis Cooper

H. biconvexa Cooper
H. colei Cooper
H. concava Cooper

H, ? costalis (Hall)

H., ? costellata Cooper
H. crinerensis Cooper

H. ? decipiens (Phleger)
H. dubia Cooper
H.ignicula (Raymond)
H. longirostris Cooper

H. matutina Cooper

H. multicostata Cooper
H. quadrata Cooper

H., sulcata Cooper

H., tenuicostata Cooper
H. tricenaria (Conrad)

H. virginiensis Cooper
Hesperorthis sp. 1
Hesperorthis sp. 2

Idiospira ? inornata (Weller)

I. panderi (Billings)

I. ? warthim Cooper

Idiostrophia costata Ulrich and

Cooper
I. nuda Cooper

SPECIES
Stage Formation
Wilderness Dark shale under
Eureka quartzite
Wilderness Wardell, Dryden,
Ridley
Ashby Lincolnshire
Trenton Decorah (Ion)
Wilderness Platteville,
Chaumont
Marmor or Crown Point or
Wilderness Chaumont?
Porterfield Botetourt
Porterfield Bromide
(Mountain Lake)
Ashby Barrel Spring
Porterfield Sevier
Marmor Valcour
Ashby Whistle Creek,
Lincolnshire,
Ellett
Ashby Tulip Creek
Ashby Lincolnshire
Wilderness Lebanon
Wilderness Bromide
(Pooleville)
Marmor Lenoir
Wilderness Guttenburg,
to Trenton Auburn,
Barnhart,
Rockland,
Curdsville
Wilderness Oranda
Porterfield Botetourt
Wilderness ? Edinburg
(middle Nidu-
lites zone)
Wilderness- Jacksonburg
Trenton
Wilderness- Tyrone, Auburn,
Trenton Hull, Rockland,
Guttenberg
Trenton Wappinger
Whiterock Boulders in
Mystic cgl.
Whiterock Upper Pogonip
(Orthidiella

zone)

Geographic
location

Ney.
Tenn., Va.

Tenn.

Minn., Iowa

Ill., Wis.,
ING:

N. Y.

Va:
Okla.

Calif.
Tenn.
Nwy:
Tenn., Va.

Okla.
Tenn.
Ga., Tenn,
Okla.

Tenn., Va.

TiN. Y., Mo.,
Wis., Ky., Va.,
Ontario

Va.
Va.
Va.

N. J.

Ontario,
Quebec,
Mo., Ky.,
N. Y., Iowa

N.Y.

Quebec

Ney.

159

691

692
588

588

160 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
I. paucicostata Cooper

I. perfecta Ulrich and Cooper

I. plicata Cooper
Idiostrophia sp. 1

Ingria cloudi (Ulrich and
Cooper )

Isophragma biseptatum Cooper

I. extensum Cooper

I. ponderosum Cooper

I. ricevillense Cooper

I. subabbreviatum Cooper

I. sulcatum Cooper

Isophragma sp. 1

Kirkina millardensis Salmon

Kullervo ornata Cooper
K. parva Cooper

K. punctata Cooper
K. sulcata Cooper

Laticrura heteropleura Cooper
L. latibrachiata Cooper
L. magna Cooper

L. pionodema Cooper

SPECIES
Stage Formation
Whiterock Upper Pogonip
(Anomalorthis
zone)
Whiterock Boulders in
Mystic cgl.,
Table Head
Whiterock Table Head
Whiterock Boulders in
Mystic cel.
Whiterock Upper Pogonip
(Orthidiella
zone)
Porterfield Botetourt,
Benbolt, Arline
Porterfield Arline,
Little Oak
Ashby or Yellow Is. on 25’
Porterfield ss. at base of
Eureka group
Porterfield Athens
Porterfield Arline
Porterfield “Lenoir”-
Little Oak
Porterfield Pratt Ferry
Whiterock Rocks equivalent
to Upper Pogo-
nip-Lehman
Porterfield Effna-Rich Valley
Porterfield Effna-Rich Valley,
Edinburg
(Liberty Hall)
Porterfield Botetourt
Porterfield Pratt Ferry
Porterfield Little Oak
Porterfield Arline
Wilderness Oranda, Martins-
burg (Salona)
Porterfield Effna-Rich Valley,

Edinburg
(Cyrt. zone),
Liberty Hall

VOL. 127
Geographic
location Page
Nev. 588

Quebec, New- 589
foundland

Newfoundland 5890

Quebec 590
Nev. 700
Va. 734
Tenn., Ala. 735
Nev. 737
Tenn. 737
Tenn. 738
Ala. 739
Ala. 740
Utah 866
Va. 527
Va. 527
Va. 528
Ala. 529
Ala. 980
Tenn. 081
Par av ae 982
Va. 983

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Leptaena ordovicica Cooper

Leptellina abbreviata Cooper
L. bella Cooper

L. delicatula (Butts)
L. incompta Cooper

L. occidentalis Ulrich and
Cooper

L. platys Cooper
L. primaria Cooper
L. pulchra Cooper

L. subcarinata Cooper
L. sublamellosa Cooper

L. tennesseensis Ulrich and

Cooper

L. transversa Cooper
Leptellina sp. 1

Leptobolus walcotti
Ruedemann
Leptobolus ? sp.1

Leptobolus ? sp. 2

Limbimurina brevilimbata Cooper Porterfield

L. insueta Cooper

SPECIES
Stage Formation
Porterfield- Oranda, Rodman,
Trenton Rysedorf, Carters,
Edinburg
(Cyrt. zone),
Martinsburg
(Salona), Salona,
dark shale under
Eureka quartzite
Wilderness Oranda
Porterfield Whitesburg,
Chatham Hill
Porterfield Little Oak
Wilderness Dark shale under
Eureka quartzite
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Porterfield Benbolt
Marmor Crown Point
Porterfield Botetourt, Effna,
Pratt Ferry,
Rich Valley,
Benbolt,
Liberty Hall
Porterfield Athens
Porterfield Benbolt,
Chatham Hill
Porterfield Arline, Red Knobs,
Little Oak,
Effna, Botetourt,
Tellico, Fetzer
Porterfield Arline
Porterfield Edinburg
(Cyrtonotella
zone)
Porterfield- Normanskill
Wilderness
Porterfield- Edinburg
Wilderness (Liberty Hall)
Porterfield- Edinburg
Wilderness (Liberty Hall)
Edinburg
(Cyrt. zone),
Botetourt
Wilderness Rodman

Geographic
location

Ala., N. Y.,
Pa., Va.,
Nev.

Va.
Tenn., Va.

Ala.
Nev.

Nev.
Va

N.Y., Vt.
Ala. .Via.

Tenn.
Va.

Ala., Tenn.,
Va.

Va.
Va.

Pa:

161

Page
820

747
748

749
750

751
751

752
753

754
755

756

758
759

214
214

214

852

853

162 SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL.

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

Lingulasma compactum Cooper

L. matutinum Cooper
L. occidentale Cooper
L. oklahomense Cooper

Lingulasma sp. 1
Lingulasma sp. 2

Lingulasma sp. 3

Lingulella alabamensis Cooper

L. brainerdi (Raymond)

L. ? clochensis (Foerste)
L. columba (Raymond)
L. decorticata Cooper

L. endopunctata Cooper

L. fostermontensis (Butts)
L. galba Cooper

L. ? glypta Cooper
L. huronensis (Billings)

L. ? huronensis minganensis
(Twenhofel and Whiting)

L. kingstonensis (Billings)
L. lirata Cooper

L. morsei (N. H. Winchell)
L. narrawayi (Wilson)

L. rideauensis Cooper
L. rugosilinea Cooper

L. spicata Cooper
L. subparallela Cooper

L. tenuitesta Cooper
L. virginiensis Cooper
Lingulella sp. 1

SPECIES
Stage Formation
Wilderness Oranda
Porterfield Arline
Ashby or Yellow ls. above
Porterfield 25’ ss. in Eureka
group
Wilderness Bromide
(Pooleville)
Wilderness Oranda
Porterfield Shippensburg
(Pinesburg)
Porterfield- Edinburg
Wilderness (Nidulites zone)
Porterfield Pratt Ferry
Marmor Chazy group
(base)
Wilderness “Lowville”
Marmor Chazy
Ashby Elway
Porterfield Botetourt
(Cybeloides bed)
Wilderness Attalla
Porterfield Bromide
(Mountain Lake)
Wilderness Bromide
(Pooleville)
Wilderness Black River
Marmor Mingan
Wilderness Black River
Porterfield Pratt Ferry, Effna,
Whitesburg,
Edinburg
(Liberty Hall)
Wilderness St. Peter
Wilderness Pamelia, Lowville
Marmor Aylmer
(Rockcliffe)
Marmor Aylmer
(Rockcliffe)
Porterfield Whitesburg
Porterfield Effna
Porterfield Columbiana
Porterfield Benbolt ?
Whiterock Upper Pogonip
(Anomalorthis

zone)

Geographic
location

Va.
Tenn.
Nev.

Okla.

Va.
Md.

Va.

Ala.
N: Yo VE

Ontario
N.Y. Vite
Va.

Va.

Ala.
Okla.

Okla.

Lake Huron

St. Lawrence
River,
Quebec

Ontario

Ala., Tenn.,
Va.

Minn.
Quebec and
Ontario

Ontario

Ontario

Tenn.
Va.

Ala.
Va.
Nev.

Page
232
233
234
233

235

235

235

195

107

PART JI

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Lingulella sp. 2
Lingulella ? sp. 3
Lingulella ? sp. 4
Lingulella ? sp. 5
Lingulella sp. 6

Lingulella sp. 7
Lingulella ? sp. 8

Liricamera nevadensis Cooper

Macrocoelia bella Cooper

M. champlainensis
(Raymond)
M. duplistriata (Willard)

M. elegantula Cooper
M. magna (Butts)

M. obesa Cooper

M. occidentalis Cooper

M. ornata Cooper

M. platys Cooper

M. plebeia Cooper

M. rotunda Cooper

M. ruedemanni( Salmon)

Macrocoelia sp. 1

Microtrypa altilis Wilson

M. ? nasuta Wilson

Mimella biconvexa Cooper
M. borealis (Billings)
M. costellata Cooper

M. extensa Cooper

M., gilbertt Cooper
M. globosa (Willard)

M. globularis Cooper

SPECIES
Stage Formation
Whiterock Oil Creek
Porterfield Little Oak
Porterfield Arline
Porterfield Arline
Marmor Aylmer
(Rockcliffe)
Ashby Dutchtown
Porterfield Pratt Ferry
Whiterock Upper Pogonip
(Orthidiella
zone)
Porterfield Bromide
(Mountain Lake)
Marmor Crown Point
Ashby Lincolnshire,
Lincolnshire
(Hogskin)
Ashby Whistle Creek
Porterfield Benbolt
Porterfield Arline
Ashby or Yellow ls. on 25’
Porterfield ss., at base of
Eureka group
Porterfield Little Oak
Ashby Lincolnshire
Marmor Lenoir
Porterfield Benbolt
? Boulder in
Rysedorf cgl.
Marmor Lenoir
Wilderness Chaumont,
Rockland
Wilderness Rockland
Wilderness Ridley, Pierce
Marmor St. Martin
Ashby Lincolnshire
( Hogskin)
Porterfield Bromide
(Mountain Lake)
Marmor Ellett
Porterfield Benbolt, Ridley,
Dryden
Porterfield Poteet (Yellow

Branch), Ridley

Geographic
location

Okla.
Ala.
Tenn.
Tenn.
Quebec

Mo.

Ala.
Nev.

Okla.
N.Y:
Tenn., Va.
Va.

Tenn Via:

Tenn.
Nev.

Ala.
Tenn.
Tenn.
Va.
N. Y.

Tenn.

Ontario

Ontario

Tenn.
Quebec
Tenn.
Okla.

Va.

Tenn., Va., Ga.

Va., Tenn.

163

Page
206
207
207
207
208

208

208
592

891
802

893

164 SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 127 .

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

M. imperator (Billings)
M. intermedia Cooper

M. laticardinia Cooper

M. latistriata Wilson

M. minganensis Twenhofel
and Whiting

M. nuclea (Butts)
M. nucleoidea Cooper
M. piger (Billings)

M. similis Cooper
M. subquadrata Cooper
M. sulcata Cooper

M. transversa Cooper
M. tumida Cooper

M. ulrichi Cooper

M. valcourensis Cooper
M. virginiensis Cooper
M. vulgaris (Raymond)

M. wardellana Cooper
Mimella sp. 1
Mimella sp. 2
Mimella sp. 3

Multicostella bursa
(Raymond)

M. convexa Cooper
M. fasciculata (Butts)

M. gerontica Cooper
M. parallela Cooper

M. planosulcata Cooper
M. platys (Billings)

M. plena Cooper
M. plicata Cooper

SPECIES
Stage Formation
Marmor Aylmer
(Rockcliffe)
Ashby Elway, Whistle
Creek
Ashby Murat, Lincolnshire
Marmor Aylmer
Marmor Mingan
Marmor Lenoir
Marmor Crown Point
Marmor Mingan
Ashby Lincolnshire
(Hogskin)
Porterfield Bromide
(Mountain Lake)
Porterfield Benbolt
Marmor Valcour
Ashby Lincolnshire
(Hogskin)
Marmor Crown Point
Marmor Probably Valcour
Ashby Whistle Creek
Marmor Crown Point,
St. Martin
Wilderness Wardell
Ashby Elway
Ashby Tulip Creek
Ashby Lincolnshire
Porterfield- Whitesburg,
Wilderness ? Chatham Hill,
Botetourt
Porterfield Bromide
(Mountain Lake)
Porterfield Little Oak
Ashby Lincolnshire
Ashby or Yellow Is. on 25’
Porterfield ss. at base of
Eureka group
Porterfield Arline
Marmor Crown Point,
St. Martin
Porterfield Arline
Ashby Lincolnshire

Geographic
location

Quebec,
Ontario
Tenn., Va.

Va., Tenn.
Ontario

St. Lawrence

River,
Quebec
Ala., Tenn.

N.Y;

St. Lawrence

River,
Quebec
Tenn.

Okla.

Was

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

M. quadrata Cooper

M. rectangulata Cooper

M. robusta Cooper

M. saffordi (Hall and Clarke)

M. semisulcata Cooper

M. sulcata Cooper

Murinella biconvexa Cooper

M. cancellata Cooper
M. muralis Cooper

M. partita Cooper

M. parva Cooper
M. plana Cooper

M. semireducta Cooper
M. speciosa Cooper

Murinella sp. 1
Murinella sp. 2
Murinella sp. 3

Neostrophia ? gregaria
Cooper

N. subcostata Ulrich and
Cooper

Neostrophia sp. 1

Nicolella angulata Cooper

N. strasburgensis Butts

Nothorthis delicatula Ulrich

and Cooper
N. tarda Cooper
N. transversa Cooper

SPECIES

Stage
Ashby

Ashby or
Porterfield

Porterfield

Porterfield
Ashby

Porterfield

Ashby
Porterfield
Porterfield-
Wilderness
Porterfield

Ashby
Ashby

Ashby
Ashby
Porterfield

Ashby
Porterfield

Wilderness
Whiterock

Porterfield

Trenton
Wilderness

Canadian or
Whiterock

Porterfield

Porterfield

Formation

Whistle Creek,
Ellett

Yellow ls. on 25
ss. at base of
Eureka group

Sevier

Probably Arline

Lincolnshire,
Lincolnshire
(Hogskin)

Bromide

,

(Mountain Lake)

Lincolnshire
(Hogskin)

Benbolt?

Poteet (Yellow
Branch), Ben-
bolt, Wardell,
Dryden

Bromide

(Mountain Lake)

Whistle Creek
Lincolnshire
(Hogskin)
Lincolnshire
(Hogskin)
Lincolnshire
(Hogskin)
Murfreesboro
Tulip Creek
Little Oak

Bromide
(Pooleville)

Boulder in
Mystic cgl.

Ward Cove?

Wappinger
Oranda

Boulder in Lévis
shale

Pratt Ferry

Pratt Ferry

Geographic

location

Ala.

165

Page
424

425
426

427
427

428

845

846
846

847

848
849

849
850
850

851
851

590
591

591

317
318

315

315
315

166 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Obolellina canadensis
(Billings )
O. dixonensis Cooper
O. erecta (Wilson)
O. magnifica Billings
O. parva (Whitfield)

O. ? biconvexa Cooper

Obolus ? cyane (Billings)
O. ? grandis Cooper

O. ? nitens Cooper

O. ? virginiensis Cooper
Obolus sp. 1

Obolus sp. 2

Obolus sp. 3

Obolus sp. 4

Obolus sp. 5

Oligorhynchia angulata
Cooper

O. bifurcata Cooper

O. elongata Cooper
O. inexpectata Cooper
O. subplana Cooper

O. subplana gibbosa Cooper

Oligorhynchia sp. 1

Onniella ? americana Cooper

O. fertilis (Ulrich)

O. paquettensts Sinclair
O. ? planoconvexa Cooper

Onychoplecia brevirostris
Cooper

O. gracilis (Raymond)

O. kindlet Cooper

SPECIES
Stage Formation
Wilderness Leray-Rockland
Wilderness Platteville
Wilderness Leray-Rockland
Wilderness Rockland
Trenton Prosser
Porterfield- Paperville
Wilderness
Whiterock Table Head
Porterfield Red Knobs
Porterfield Rich Valley
Porterfield Effna, Red Knobs
Whiterock Table Head
Marmor Blackford
Porterfield Pratt Ferry
Porterfield Pratt Ferry
Porterfield Effna
Ashby- Lincolnshire
Wilderness (Hogskin),
Ward Cove,
Sevier
Porterfield- Benbolt, Sevier,
Wilderness Ward Cove,
Witten, St. Luke,
Surgener
Wilderness Wardell
Porterfield Red Knobs
Ashby- Lincolnshire,
Porterfield Lincolnshire
(Hogskin),
Ward Cove,
Sevier
Ashby Lincolnshire
(Hogskin)
Porterfield- Dryden
Wilderness
Trenton Hermitage
Trenton Martinsburg
(Curdsville)
Wilderness Rockland
Trenton Hermitage
Marmor Lenoir
Marmor Crown Point
Whiterock Table Head

VOL. 127
Geographic

location Page
Ontario 230
Ill. 230
Ontario 231
Ontario 231
Minn. 232
Tenn. 189
Newfoundland 190
Tenn. 190
Va. 190
Va., Tenn. 191
Newfoundland 192
Va. 192
Ala. 193
Ala. 193
Va. 193
Tenn., Va. 659
Tenn., Va. 659
Tenn. 660
Tenn. 661
Tenn. 662
Tenn. 662
Tenn. 663
Tenn. 053
Tenn., Va. 054
Ontario 955
Tenn. 955
Tenn. 530
Ne. Ve 531
Newfoundland 532

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

O. longirostris (Billings)

O. matutina Cooper
O. obesa Cooper
O. tenuis Cooper

Onychoplecia sp. 1

Opikina alata Cooper

O. bellula Cooper

O. clara (Okulitch)
O. dorsatiformis Cooper

O. ? dubia Cooper
O. eximia Cooper

O. expatiata Cooper
O. extensa Cooper
O. formosa Cooper

O. glabella Cooper
O. gregaria Cooper

O. inquassa (Sardeson)

O. lirata Cooper
O. maja Cooper
O. matutina Cooper
O. minnesotensis

(N. H. Winchell)
O. nasuta Cooper
O. parvula Cooper
O. ? planulata Cooper
O. pulchella Cooper

O. quadrata Cooper
O. septata Salmon
O. speciosa Cooper

O. subplanodorsata Cooper

SPECIES
Stage Formation
Marmor Mingan
Marmor Jasper, Everton
Marmor Row Park
Porterfield Bromide
(Mountain Lake)
Porterfield Chota
Porterfield Edinburg
(Nidulites zone)
Porterfield Edinburg
(Cyrt. zone),
Shippensburg
Wilderness Chaumont
Porterfield Edinburg
(Nidulites,
Cyrtonotella
zone)
Porterfield Botetourt
Wilderness Lebanon, Camp
Nelson
Porterfield Bromide
(Mountain Lake)
Wilderness Bromide
(Pooleville)
Wilderness Bromide
(Pooleville)
Porterfield Arline
Porterfield Bromide
(Mountain Lake)
Wilderness Decorah
(Guttenberg)
Trenton Decorah (Ion)
Wilderness Ridley
Porterfield Arline
Wilderness Platteville
(McGregor)
Porterfield Chatham Hill
Porterfield Benbolt
Wilderness Pierce
Porterfield Benbolt
Wilderness Ridley
Wilderness Lebanon
Wilderness Ridley, Wardell,
Dryden, Pierce
Wilderness Wardell

Geographic

location

St. Lawrence

River,
Quebec
Ark.
Pa., Md.
Okla.

Tenn.

Via

Md., Va.

Quebec
Va.

Va.
Ky., Tenn.

Okla.
Okla.
Okla.

Tenn.
Okla.

Minn.

Minn.

Ga.

Va.

Ill., Minn.,

Wis.

Va.

Va.

Tenn.

Va.

Tenn.

Tenn.

Ga., Tenn.,
Va.

Tenn., Va.

167

Page
533

920

168 SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 127

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
O. transitionalis (Okulitch)
O. transversa Cooper
O. varia Cooper
O. wagneri (Okulitch)
Opikina sp. 1
Opikina sp. 2

Opikina sp. 3

Opikina sp. 4
Opikina sp. 5

Orbiculoidea eximia Cooper

O. linvillensis Cooper

Orthambonites acutiplicatus
(Raymond)

O. angulatus Cooper

O. bellus Cooper

O. bielsteint Cooper

O. bifurcatus Cooper

O. blountensis Cooper
O. brachiophorus Cooper

O. buttsi (Schuchert and
Cooper )

O. dinorthoides Cooper

O. divaricatus Cooper

O. eucharis (Ulrich and
Cooper)

O. ? exfoliatus (Raymond)
O. friendsvillensis Cooper
O. michaelis (Clark)

O. minus Cooper
O. minusculus ( Phleger )

O. minutus Cooper
O. mostellerensis Cooper

SPECIES
Stage Formation
Wilderness Chaumont
Porterfield Ward Cove
Wilderness Carters, Dryden
Wilderness Chaumont
Porterfield Benbolt
Wilderness Bromide
(Pooleville)
Porterfield Edinburg
(Cyrtonotella
zone)
Porterfield Little Oak
Ashby Ellett
Wilderness Bromide
(Pooleville)
Wilderness Oranda
Marmor Day Point?
Porterfield Arline?
Porterfield Chatham Hill
Wilderness- Edinburg, Benbolt,
Trenton Shippensburg
(Pinesburg),
Oranda,
Martinsburg
(Salona)
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Porterfield Arline
Porterfield Effna-Rich Valley,
Botetourt
Porterfield Little Oak
Whiterock Oil Creek
Porterfield Effna-Rich Valley
Whiterock Upper Pogonip
(Orthidiella
zone)
Marmor Day Point
Porterfield Arline
Whiterock Swan Peak,
Kanosh
Ashby Tulip Creek
Whiterock Mazourka,
Upper Pogonip
Marmor McLish
Porterfield Little Oak

Geographic
location

Quebec
Va.

Ala., Tenn.
Quebec
Va.

Okla.

Ney:

Tenn.
Va.
Md: Pas, Wa:

Nev.

Tenn., Va.
Va.

Ala.

Okla.
Va.
Nev.

Ne Ys
Tenn.
Utah

Okla.
Calif., Nev.

Okla.
Ala.

Page
921
921
922
923
924
024

925
925
925
275
276
204
204

295
296

207

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
O. multicostellatus Cooper

O. neumani Cooper

O. occidentalis Cooper

O. parvicrassicostatus Cooper

O. paucicostatus Cooper

O. rectangulatus Cooper
O. rotundiformis Cooper
O. subconvexus Cooper

O. tennesscensis Cooper

O. tenuicostatus Cooper

Orthidiella carinata Ulrich
and Cooper

O. costellata Cooper

O. extensa Ulrich and Cooper

O. longwelli Ulrich and Cooper

Orthidiella sp. 1

Orthidium bellulum Ulrich
and Cooper

O. fimbriatum Cooper
O. gemmiculum (Billings)

O-xoplecia abnormis Cooper
O. costellata Cooper

O. depressa Cooper

O. eidsonensis Cooper

SPECIES
Stage Formation
Porterfield- Edinburg
Wilderness (Cyrt. zone),
Oranda
Porterfield Tellico
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Porterfield Effna, Botetourt,
Chatham Hill,
Benbolt
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Porterfield Shippensburg
(Pinesburg )
Porterfield Athens
Whiterock Oil Creek
Porterfield Arline, Botetourt,
Little Oak
Porterfield Pratt Ferry
Whiterock Upper Pogonip
(Orthidiella
zone)
Whiterock Upper Pogonip
(Orthidiella
zone)
Whiterock Upper Pogonip
(Orthidiella
zone)
Whiterock Upper Pogonip
(Orthidiella
zone)
Whiterock Upper Pogonip
(Orthidiella
zone)
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Whiterock Table Head
Whiterock Boulders in Lévis
cgl. (No. 2)
Porterfield Effna
Ashby Whistle Creek
Porterfield Effna
Ashby Lincolnshire

Geographic
location

Va.
Nev.
Md.
Tenn.

Okla.
Tenn.

Ala.

Nev.

Nev.

Nev.

Nev.

Nev.

Nev.

Newfoundland
Quebec

Va.
Va.
Va.
Tenn., Va.

Page
307

307

308

309

310

310

311
312

313
314

338

338

339

339

340

340

340
341

539
540
540
541

170 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

O. filosa Cooper

O. gibbosa Cooper

O. globularis Cooper

O. gouldi Ulrich and Cooper

O. holstonensis Willard

O. magnaplicata Cooper
O. marmorata Cooper

O. monitorensis Cooper

O. multicostellata Cooper

O. nevadensis Cooper
O. occidentalis (Butts)

O. parva Cooper

O. pennsylvanica Cooper
O. planiventra Cooper
O. planulata Cooper

O. plicata Cooper
O. recta Cooper

O. simulatrix (Bassler)

Pachyglossa biconvexa
Cooper

P. dorsiconvexa Cooper

P. ? elderi (Whitfield)

P. pachydermata Cooper

SPECIES
Stage Formation
Porterfield Bromide
(Mountain Lake)
Porterfield Effna, Ward Cove,
Red Knobs,
Little Oak
Trenton Martinsburg
(Salona)
Porterfield Bromide
(Pooleville)
Porterfield Effna, Botetourt,
Whitesburg,
Red Knobs,
Liberty Hall
Porterfield Shippensburg
(Pinesburg)
Porterfield Red Knobs
Ashby or Yellow ls. on 25’
Porterfield ss. at base of
Eureka group
Porterfield Benbolt, Sevier,
Chatham Hill,
Edinburg
(Cyrt. zone)
Wilderness Dark beds under
Eureka quartzite
Wilderness Bromide
(Pooleville? )
Porterfield Benbolt
Trenton Salona
Porterfield Sevier
Wilderness Carters
Porterfield Red Knobs
Ashby Lincolnshire,
Lincolnshire
(Hogskin)
Wilderness Oranda
Wilderness Bromide
( Pooleville)
Porterfield Pratt Ferry
Wilderness Platteville
(McGregor),
Decorah
(Spechts Ferry)
Porterfield Effna, Botetourt,
Benbolt,

Chatham Hill,
Pratt Ferry

Geographic
location

Okla.

Ala., Tenn.,
Va.

Md.
Tenn.

Nev.

Tenn., Va.

Nev.
Okla.
Va.
Pas

Tenn.
Ala.

Tenn.
Tenn.

Md., Pa., Va.

Okla.

Ala.
Minn., Wis.

Ala., Va.

127

Page
542

543

544
545

545

546
547
548

549

559
551
552
553

554
554

555
550

556
224

225
225

225

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Palaeoglossa ? belli
(Billings )
P. mysticensis Cooper

P. ? pulicis (Sinclair)
Palaeoglossa sp. 1

Palaeostrophomena angulata
Cooper

P. resupinata Cooper

P. ? rugosa Cooper

P. superba Cooper

P. subtransversa Cooper

Parallelelasma pentagonum
Cooper

Parastrophina bernensis
(Sardeson)

P, bilobata Cooper
P. hemiplicata (Hall)

P. rotundiformis (Willard)
Parastrophina sp. 1

Parastrophina sp. 2

Paterula amii Schuchert

P. perfecta Cooper

P. polita Cooper
P, subcircularis Cooper

Paucicostella canadensis
Cooper

Paucicrura matutina Cooper

SPECIES
Stage Formation
Marmor St. Martin
Whiterock Boulders in
Mystic cgl.
Wilderness Black River?
Porterfield Edinburg
(Cyrtonotella
zone)
Porterfield Botetourt
Porterfield Benbolt
Porterfield Botetourt
Porterfield Arline, Fetzer
Porterfield Arline
Porterfield Pratt Ferry
Trenton Prosser
Porterfield Pratt Ferry
Trenton Martinsburg
(Salona),
Salona
Trenton Prosser
Trenton Martinsburg
(Salona)
Wilderness Oranda
Porterfield ? Quebec City,
Normanskill,
Humber Arm
Porterfield- Whitesburg,
Wilderness Pratt Ferry,
Botetourt,
Oranda, Arline,
Edinburg
(Liberty Hall)
Wilderness Viola
Porterfield Stringtown-
Womble
Whiterock Boulder in
Mystic cgl.
Porterfield Edinburg
(Cyrtonotella
zone),
Shippensburg

(Pinesburg)

Geographic
location

Quebec
Quebec

Quebec
Va.

Ala.

Iowa, Minn.,
Wis.

Ala.

Vai, Pa:

lowa
Va.
Was

Quebec, N. Y.,
Newfoundland

Ala., Tenn.,
Va.

Okla.
Okla.

Quebec

Md., Pa., Va.

171

Page
221

221
221
222
702
704
705
700
797

614
604
605
606
607
608

608

238

238

239
239

712

957

172 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
P. rogata (Sardeson)

P. subplana Cooper

P. virginica Cooper

Paurorthis catawbensis Butts

P. fasciculata Cooper

P. fascifera Cooper
P. gigantea Cooper

P. longa Cooper

P.. macrodeltoidea Cooper

P. magna Cooper

P. ponderosa Cooper

P. spinosa Cooper

Paurorthis sp. 1
Paurorthis sp. 2

Pelonomia delicatula
(Billings)

Perimecocoelia elliptica
Cooper
P. semicostata Cooper

P. triangulata Cooper

Petrocrania cicatricula
Willard

P. dixonensis Cooper

P. halli (Sardeson)

P. inflata Cooper

SPECIES
Stage Formation
Wilderness- Auburn, Prosser,
Trenton Decorah (Ion)
Trenton Martinsburg
(Salona)
Porterfield- Edinburg
Wilderness (Nidulites zone)
(Liberty Hall)
Porterfield Botetourt, Block-
house, Tellico
Porterfield Little Oak,
Tellico, Arline
Porterfield Ward Cove
Wilderness Dark shale under
Eureka quartzite
Porterfield Arline
Wilderness Bromide
(Mountain Lake)
Ashby Lincolnshire,
Lincolnshire
(Hogskin)
Porterfield Benbolt, Sevier,
Shippensburg
(Pinesburg)
Porter field- Edinburg
Wilderness (Nidulites zone)
Porterfield Athens
Porterfield Sevier
Whiterock Table Head
Porterfield Arline
Porterfield Effna, Botetourt,
Benbolt,
Pratt Ferry,
Liberty Hall,
Edinburg
Porterfield Effna
Ashby? Probably Lincoln-
shire (Hogskin)
Wilderness Platteville
Wilderness- Decorah
Trenton (Spechts Ferry)
Wilderness Bromide

(Pooleville)

Geographic
location

Mo., Minn.,
Wis.
Va.

Va.

Va., Tenn.
Ala., Tenn.

Tenn.
Nev.

Tenn.
Okla.

Tenn.

Md., Tenn.,
Va.

Va.

Tenn.
Tenn.

N eatoundiond

127

Page
957

958

958

594

596
287

287
288

288

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
P. ? magna Cooper
P. prona (Raymond)

P. trentonensis (Hall)
Petrocrania sp. I

Petrocrania ? sp. 2
Petrocrania sp. 3

Petroria rugosa Wilson

Philhedra depressa Cooper
P. ferruginea Cooper

P. minor Cooper

Philhedra ? sp. 1

Phragmorthis buttsi Cooper

P. crassa Cooper

Pionodema camerata Cooper
P. circularis (N. H. Winchell)
P. conradi (N. H. Winchell)
P. crassipunctata Cooper

P. minnesotensis Cooper
P. minuscula Willard

P. sinuata Okulitch

P. subaequata (Conrad)

P. sulcata Cooper

P, tennesseensis Cooper

SPECIES
Stage Formation
Porterfield Effna
Marmor Crown Point,
Mingan
Trenton Martinsburg
(Salona)
Wilderness Ridley, Dryden
Porterfield Liberty Hall
Porterfield Bromide
(Mountain Lake)
Probably Beaverfoot
Canadian
Porterfield Prosser
Wilderness Red Knobs
Porterfield Pierce
Porterfield Bromide
(Mountain Lake)
Porterfield Effna-Rich Valley,
Pratt Ferry,
Arline,
Liberty Hall
Trenton Martinsburg
(Salona)
Wilderness Sevier
(Bacon Bend)
Trenton Decorah (Ion)
Wilderness Platteville
(McGregor)
Porterfield Benbolt
Trenton Decorah (Ion?)
Wilderness Lebanon, Hatter,
Camp Nelson,
Witten
Wilderness Chaumont
Wilderness Decorah
(Spechts Ferry,
Guttenberg),
Auburn,
Barnhart
Wilderness Nealmont, Cane
Creek
Trenton Hermitage

Geographic
location

Va.

INGYES St:
Lawrence
River,
Quebec

Va.

Ga., Tenn.
Va.
Okla.

British
Columbia

Wis.

Tenn.

Tenn.
Okla.

Ala., Tenn.,
Va.

We

Tenn.

Iowa, Minn.,

Wis.
Iil., Minn.,
Wis.
Va.
Minn.
Tenn., Pa.,
Ky., Va.

Quebec

Towa, Minn.,

Wis., Mo.

Pa.) Vaz

Tenn.

173

Page
289
289

290
290

290
291

746

201
291
292
292

510

994

995

174 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
P. uniplicata Cooper

Pionodema sp. I

Pionomena ? dubia Cooper
P. neumani Cooper

P. pulchra Cooper

Platymena ? bellatula Cooper

P. plana Cooper

Plectocamara aseptata
Cooper
P. costata Cooper

P. erecta Cooper
P. magna Cooper

P. rotunda Cooper
P. sulcata Cooper
P. transversa Cooper

Plectoglossa oklahomensis
Cooper
Plectoglossa sp. I

Plectorthis australis Cooper

P. compacta Cooper

P. lebanonensis Cooper

P. mazourkaensis Phleger
P. obesa Cooper

P. patula (Phleger)
P. pennsylvanica Cooper
P. ponderosa Cooper

P. punctata Cooper
P. symmetrica Cooper

SPECIES
Stage Formation
Wilderness- Decorah
Trenton (Spechts Ferry-
Ion)
Wilderness Chaumont
Porterfield Effna
Ashby Elway,
New Market,
Lincolnshire
Wilderness Grazier
Wilderness Bromide
(Pooleville)
Porterfield Arline
Porterfield Benbolt, Ward
Cove, Sevier
Ashby Lincolnshire,
Lincolnshire
(Hogskin),
Ward Cove
Wilderness Wardell
Porterfield Edinburg (Cyrt.),
Shippensburg
(Pinesburg)
Porterfield Chatham Hill
Porterfield Benbolt
Porterfield- Edinburg
Wilderness (Nidulites zone)
Wilderness Bromide
(Pooleville)
Porterfield Benbolt
Porterfield Arline,
Little Oak
Porterfield Arline
Wilderness Lebanon
Ashby Mazourka
Wilderness Dark shale under
Eureka quartzite
Ashby Mazourka
Wilderness Rodman
Trenton Martinsburg
(Salona)
Ashby Tulip Creek
Wilderness Bromide

(Pooleville)

Geographic
location

Iowa, Minn.
Wis.

Ni, ¥.

Va.
Md:, ‘Pa.
Tenn., Va.

Pa.

Okla.

Tenn.

Tenn., Va.

Tenn., Va.

Tenn.
Md., Va.

VOL. 127

Page

996

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
P. tenuis Cooper
P. transversa Cooper
Plectorthis sp. 1

Plectorthis sp. 2

Pleurorthis convexa Cooper
P. corinna (Billings)

P. costellata Cooper

P. fascicostellata Cooper

P. imbecilis (Billings)

P. tritonia (Billings)

Pleurorthis sp. 1
Pleurorthis sp. 2

Porambonites ? umbonatus
Cooper

Porambonites ? sp. 1

Porambonites ? sp. 2
Porambonites ? sp. 3

Porambonites sp. 4

Productorthis agilera
(Willard)
P. americana Cooper

Protorhyncha dubia (Hall)

Protozyga costata Cooper
P. elongata Cooper
P. exigua (Hall)

P. loeblichi Cooper

SPECIES
Stage Formation
Porterfield Benbolt
Porterfield Ward Cove
Porterfield- Shippensburg
Wilderness (Pinesburg )
Porterfield Murfreesboro
Whiterock Boulder in
Mystic cel.
Whiterock Boulder in
Mystic cgl.
Whiterock Boulder in
Mystic cel.
Whiterock Boulder in
Mystic cel.
Whiterock Table Head
Whiterock Boulder in Lévis
shale (boulder
No. 2)
Whiterock Table Head
Whiterock Table Head
Whiterock Upper Pogonip
(Rhysostrophia
zone )
Whiterock Upper Pogonip
(Anomalorthis
zone)
Whiterock Table Head
Whiterock Upper Pogonip
(Orthidiella
zone)
Trenton Salona
Porterfield Effna
Porterfield Arline, Botetourt,
Little Oak
Marmor Chazy
Porterfield Bromide
(Mountain Lake)
Porterfield Bromide
(Mountain Lake)
Wilderness Rockland
(Napanee)
Wilderness Bromide

(Pooleville)

Geographic
location

Va.
Va.
Pa.

Tenn.

Quebec
Quebec
Quebec
Quebec

Newfoundland
Quebec

Newfoundland
Newfoundland

Nev.

Calif.

Newfoundland
Nev.

Pa.

Va.

Tenn., Ala.

Okla.

175

Page
454
454
455
455
329
330
330
331
331
332
332
333

609

609

610
610

611

335

336

618
676

677
678

679

176 SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 127

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
P. magnicostata Cooper

P. microscopica Cooper

P. nasuta Cooper

P. nicolleti (Winchell and

Schuchert)
P. profunda Cooper
P. rotunda Cooper

P. rotundiformis Cooper
P. superba Cooper

P. twmida Cooper

P. uniplicata Cooper

Protozyga sp. I

Pseudobolus gibbosus
(Willard)
Pseudobolus sp. t

Pseudolingula aquilina
Sinclair

P. ? eva (Billings)

P. ? imperfecta Cooper

P. ? luttrellensis Cooper
P. pyxidata Sinclair

P. ? sculptata Cooper
Pseudolingula sp. 1

Ptychoglyptus ? kindlei
Cooper

P. ? matura Cooper
P. virginiensis Willard

Ptychoglyptus ? sp. 1

Ptychopleurella globularis

Cooper

SPECIES
Stage Formation
Porterfield Bromide
(Mountain Lake)
Ashby- Elway, Ward Cove,
Porterfield Lincolnshire
(Hogskin)
Ashby Whistle Creek
Wilderness Platteville
(McGregor)
Trenton Trenton
Wilderness Lebanon, Ridley,
Wardell, Plattin
(Macy), Barn-
hart, Dryden
Ashby Lincolnshire
Wilderness Auburn, Barnhart
Porterfield Effna
Porterfield Benbolt,
Murfreesboro
Porterfield Meadow
Ashby Murat
Porterfield Effna
Marmor ? Chazy?
Wilderness Black River?
Wilderness Bromide
(Pooleville)
Wilderness Moccasin
Wilderness Black River?
Wilderness Camp Nelson
Porterfield Shippensburg
(Pinesburg)
Whiterock Table Head,
boulder in
Mystic cgl.
Porterfield Pratt Ferry
Porterfield Effna, Pratt
Ferry, Botetourt,
Edinburg,
Liberty Hall,
Rich Valley
Whiterock Boulder in
Mystic cel.
Porterfield Arline

Geographic

location Page
Okla. 680
Tenn., Va. 681
Va. 681
Ill., Minn., 682

Wis.
Quebec 683
Ga., Mo., 683

Tenn., Va.
Tenn. 685
Mo. 686
Va. 687
Va. 687
Tenn. 688
Va. 194
Va. 195
Quebec 215
Quebec 215
Okla. 215
Tenn. 216
Quebec 217
Ky. 217
Md. 217

Newfoundland, 816
Quebec

Ala. 817
Ala., Tenn., Va. 818

Quebec 810

Tenn. 385

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Concluded

Species
P. glypta Cooper
P. lamellosa (Raymond)
P. mediocostata Cooper
P. oklahomensis Cooper
P. porcia (Billings)
P. rectangulata Cooper
P. sulcata Cooper
P. uniplicata Cooper

Rafinesquina lennoxensis
Salmon
R. olliformis Salmon

R. planulata Cooper
R. prestonensis Salmon

R. sinclairi Salmon

R. trentonensis (Conrad)

Reuschella americana Cooper

R. edsoni (Bassler)
R. vespertina Cooper

Rhipidomena filicostellata
Cooper
R. mesleri Cooper

R. subparallela Cooper
R. tennesseensis (Willard)
R. tenuitesta (Willard)

Rhipidomena sp. I

Rhynchotrema kentuckiense
Fenton and Fenton

R. wisconsinense Fenton and
Fenton

Rhysostrophia elliptica
Ulrich and Cooper

SPECIES
Stage Formation
Marmor Lenoir
Marmor Crown Point
Porterfield Effna-Rich Valley
Marmor McLish
Marmor St. Martin
Porterfield Effna-Rich Valley
Wilderness Oranda
Porterfield Benbolt
Wilderness Rockland
(Napanee)
Wilderness Rockland
(Napanee)
Wilderness Oranda
Wilderness Rockland,
Decorah
(Guttenberg )
Wilderness Auburn, Barn-
hart, Decorah
(Guttenberg)
Wilderness- Decorah
Trenton (Guttenberg),
Hermitage
Wilderness Oranda,
Jacksonburg
Trenton Sherman Fall
Wilderness Dark shale under
Eureka quartzite
Porterfield Sevier
Ashby Lincolnshire
(Hogskin)
Ashby Elway
Porterfield Benbolt
Ashby Lincolnshire,
Lincolnshire
(Hogskin)
Porterfield Arline
Trenton Trenton
Trenton Decorah (Ion)
Whiterock Boulder in

Mystic cel.

Geographic
location

Tenn.
NY:
Va.
Okla.
Quebec
Va.
Va.
Va.

N. Y., Ontario
Ontario

Va.

Til.

Mo., Wis.

Wis., Tenn.

Vag No J. Pa.

Vt.
Nev.

Tenn.
Tenn.
Tenn.

Tenn., Va.
Tenn., Va.

Tenn.

Ky.

Minn., Wis.

Quebec

177

Page

888

976
978
979
867
868
870
870
872
873
629

630

559

178 SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL.

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
R. nevadensis Ulrich and
Cooper

R. occidentalis Ulrich and
Cooper

R. transversa Ulrich and
Cooper

Rhysostrophia sp. 1

Rhysostrophia sp. 2

Rhysotreta corrugata Cooper

Rostricellula acutiplicata
Cooper
R. ainsliei (N. H. Winchell)

R. ? angulata Cooper

R. basalaris Cooper

R. colei Cooper
R. compressa Cooper

R. costata Cooper
R. cuneata Cooper

R. cuneiformis (Fenton and
Fenton)

R. decorahensis (Fenton and
Fenton)

R. elliptica Cooper

R. major (Raymond)

R. minnesotensis (Sardeson)

R. ? minuta Cooper

R. missouriensis (Fenton and
Fenton)

R. multicostata Cooper

R. nucleolata Cooper

R. orientalis (Billings)

SPECIES
Stage Formation
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Whiterock Boulder in
Mystic cgl.
Whiterock Upper Pogonip
Whiterock Table Head
Porterfield Pratt Ferry
Trenton Prosser
Wilderness Decorah
(Spechts Ferry)
Wilderness Dark shale under
Eureka quartzite
Marmor Mosheim, Lenoir,
Tumbez, Row
Park
Trenton Decorah (Ion)
Wilderness Camp Nelson,
Lebanon, Wells
Marmor Lenoir
Porterfield Bromide
(Mountain Lake)
Wilderness Plattin (Macy),
Barnhart
Wilderness Decorah
(member ?)
Marmor New Market
Marmor Valcour
Wilderness Platteville
(McGregor),
Decorah
(Spechts Ferry )
Trenton Hermitage
Wilderness Barnhart,
Plattin (Macy)
Marmor Ellett
Wilderness Platteville
(Pecatonica )
Marmor Mingan

Geographic
location

Nev.
Nev.

Quebec

Nev.
Newfoundland

Ala.

Minn.
Minn.
Nev.

Ala. Pas
Tenn., Va.

Towa, Minn.
Ky., Tenn.

Ala.
Okla.

Mo.
Iowa
Va.
INESe

Ill., Minn.,
Wis.

Minn.

St. Lawrence
River,
Quebec

127

Page
559

559

559

560
560

259
630
631
632
632
634
634

636
637

637
638
638

639
639

640
641

641
642

642

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
R. ovata Cooper
R. parva Cooper
R. plattinensis (Fenton)

R. plena (Hall)

R. plena altilis (Hall)

R. plena plicifera (Hall)

R. pristina (Raymond)

R. pulchra Cooper

R. raymondi Cooper

R. rostrata Ulrich and Cooper

R. rotundata Cooper

R. subtransversa Cooper
R. transversa Cooper

R. triangulata Cooper
R. truncata Cooper
R. tumidula Cooper
R. variabilis Cooper
R. varicosta Cooper
R. wilsonae Cooper

Rostricellula sp. 1

Rosiricellula sp. 2
Rostricellula sp. 3

Salonia magnaplicata Cooper
and Whitcomb

Scaphelasma septatum Cooper

Scaphorthis kayi Cooper

SPECIES
Stage Formation
Wilderness Hostler, Wardell,
Dryden,
Ooltewah
Wilderness Bromide
( Pooleville)
Wilderness Plattin (lower )
Marmor Aylmer, Valcour,
Row Park,
St. Martin
Marmor Valcour
Marmor Valcour
Marmor Crown Point
Wilderness Decorah
(Guttenberg)
Marmor St. Martin
Wilderness Benbolt, Ridley,
Wardell, Dryden,
Pierce
Wilderness Swift Current,
Cloche Island
Wilderness Witten
Wilderness Bromide
(Pooleville)
Marmor Mingan
Wilderness Lebanon
Wilderness Dryden
Wilderness Ridley
Marmor Lenoir
(Douglas Lake)
Marmor Aylmer
(Rockcliffe)
Wilderness Bromide
(Pooleville)
Wilderness Wardell
Trenton Prosser
Trenton Salona
Porterfield Pratt Ferry
Porterfield Edinburg
(Cyrtonotella
zone),
Shippensburg

(Pinesburg )

Geographic
location

Pa., Tenn.,
Va.

Okla.

Mo.

N.Y, Vt,
Pa., Quebec,
Ontario

Nee

N. Y.

Nw

Minn.

Quebec
Tenn., Va.
Ontario

Tenn.
Okla.

St. Lawrence
River,
Quebec

Tenn.

Was

Ga.

Tenn.
Ontario
Okla.

Va.
Minn.

Bas

Ala.

Md., Pa., Va.

179

503

180

SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

S. perplexa Cooper

S. virgimensis Cooper
Scaphorthis sp. t

Schizambon cuneatum
Willard
S. duplicimuratum Hudson

S. hirsutum Cooper

S. irregulare Cooper
S. lineatum Cooper

S. macrothyris Cooper

S. perspinosum Cooper

S. subradiatum Cooper
Schizambon sp. 1
Schizambon sp. 2

Schizocrania filosa (Hall)

Schizotreta canadensis Wilson
S. corrugata Cooper

S. microthyris Cooper

S. pannea (Willard)

S. papilliformis Ruedemann

S. posteroconvexa Cooper
S. shuleri (Willard)

S. subconica Cooper
S. willardit Cooper
Schizotreta sp. 1

Siphonotreta americana
Cooper

Skenidioides anthonensis
(Sardeson)

S. billingsi Schuchert and
Cooper

S. convexus Cooper

S. costatus Cooper

SPECIES
Stage Formation
Porterfield Effna-Rich Valley,
Botetourt
Porterfield Chatham Hill
Porterfield Effna-Rich Valley
Porterfield Effna, Botetourt
Marmor Crown Point,
Mingan,
St. Martin
Ashby Murat
Porterfield Arline
Wilderness Wardell
Porterfield- Benbolt, Wardell
Wilderness
Wilderness Bromide
(Pooleville)
Porterfield Arline
Porterfield Effna-Rich Valley
Porterfield Pratt Ferry
Wilderness- Barnhart,
Trenton Martinsburg
Wilderness Chaumont
Porterfield Pratt Ferry
Wilderness Oranda
Porterfield Effna
Porter field- Normanskill
Wilderness (Mount Merino)
Porterfield Athens
Porterfield Effna, Botetourt,
Rich Valley
Porterfield Pratt Ferry
Porterfield Pratt Ferry
Ashby Lincolnshire
(Hogskin)
Porterfield Arline
Wilderness Platteville
(Pecatonica)
Wilderness Rockland
Porterfield Pratt Ferry
Porterfield Liberty Hall,

Red Knobs

Geographi
location

VOL.

Cc

N. Y., Quebec,

St. Lawrence

River
Va.
Tenn.
Va.

Va.

Okla.
Tenn.

Vas
Ala.

Mo., Va.

Ontario
Ala.
Va.
Vas
Nix?

Tenn.
Va.

Ala.

Ala.
Tenn.

Tenn.

Iil., Minn.
Ontario

Ala.
Tenn., Va.

127

492
493

PART I

CHAZYAN AND RELATED BRACHIOPODS—COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
S. elongatus Cooper

S. halli( Hall and Clarke)
S. mediocostatus Cooper

S. obtusus Cooper

S. oklahomensis Cooper
S. perfectus Cooper

S. platys Cooper

S. rectangulatus Cooper
S. transversus Cooper

Sowerbyella aequicostellata
Cooper

S. aequistriata (Willard)

S. angulata Cooper

S. bellarugosa Ulrich and
Cooper

S. cava Cooper

S. compacta Cooper

S. curdsvillensis (Foerste)
S. eximia Cooper

S. indistincta Cooper

S. lebanonensis Bassler

S. medio plicata Cooper

S. merriami Cooper

S. monilifera Cooper

S. nasuta Cooper
S. negritus (Willard)

S. parva Cooper
S. perplexa Cooper

SPECIES
Stage Formation
Trenton Martinsburg
(Salona)
Wilderness Lebanon
Porterfield Chatham Hill,
Benbolt
Porterfield- Edinburg
Wilderness (Nidulites zone)
Porterfield Bromide
(Mountain Lake)
Wilderness Bromide
(Pooleville)
Porterfield Little Oak
Wilderness Oranda
Porterfield Effna-Rich Valley
Porterfield Edinburg
(Nid. and Cyr-
tonotella zone),
Shippensburg
(Pinesburg)
Wilderness Wardell
Trenton Hermitage
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Wilderness Oranda, Martins-
burg (Salona),
Salona
Porterfield Benbolt, Dryden
Trenton Martinsburg
(Curdsville)
Wilderness- Oranda, Martins-
Trenton burg (Salona)
Porterfield Bromide
(Mountain Lake)
Wilderness Lebanon
Ashby Lincolnshire
Wilderness Dark shale under
Eureka quartzite
Trenton Decorah (Ion)
Porterfield Chatham Hill
Porterfield Effna, Ward Cove,
Botetourt,
Chatham Hill,
Whitesburg
Porterfield Ward Cove
Porterfield Chatham Hill

Geographic
location

Was

Tenn.
Va.

PRasoVias
Va.

MdsPa., Va.

Tenn.
Ala.
Nev.

Pay Vas;

Ala., Tenn.,
Va.

Ky., Tenn.,
Va.

Va.

Okla.

Tenn.
Va.
Ney.

Towa, Minn.,
Wis.

Va.

Va.

Wide
Va.

181

Page
494

495
496

497
498
499
500

500
501

774

775
776
777

777

778
780
781
782
782
784
785
785

787
788

789
790

182 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
S. plicatifera Cooper

S. punctostriata (Mather )

S. silicica Cooper

S. silicica nana Cooper
S. socialis Cooper

S. socialis crassa Cooper
S. subcarinata (Ulrich)
S. variabilis Cooper

S. varicostellata Cooper
S. vulgata Cooper

Sowerbyella sp. 1

Sowerbyella sp. 2
Sowerbyella sp. 3

Sowerbyella sp. 4

Sowerbyites delicatus Cooper

S. gildersleevei Cooper
S. hami Cooper

S. lamellosus Cooper

S. subnasutus Cooper
S. triseptatus (Willard)

Sowerbyites sp. 1

Sphenotreta acutirostris
(Hall)

S. cuneata Cooper

S. sulcata Cooper

Spinilingula intralamellata
Cooper

Spondylotreta concentrica
Cooper
S. ? declivis (Willard)

SPECIES
Stage Formation
Porterfield Bromide
(Mountain Lake)
Wilderness Rockland, Decorah
(Guttenberg)
Porterfield Arline
Porterfield Arline
Wilderness Wardell
Wilderness Wardell
Wilderness Carters
Wilderness Bromide
( Pooleville)
Porterfield Arline, Little Oak
Porterfield Bromide
(Mountain Lake)
Porterfield Bromide
(Mountain Lake)
Wilderness Rodman
Wilderness Dark shale under
Eureka quartzite
Ashby or Yellow Is. on 25’
Porterfield ss. at base of
Eureka group
Porterfield Sevier
Ashby Lincolnshire
Wilderness Bromide
(Pooleville)
Ashby- Bromide
Porterfield (Mountain Lake)
Tellico, Great
Basin
Ashby Lincolnshire
Ashby Lincolnshire,
Lincolnshire
(Hogskin)
Ashby or Quebec City
Porterfield
Marmor Crown Point
Porterfield Sevier
Marmor McLish
Porterfield Pratt Ferry
Porterfield Pratt Ferry
Porterfield Effna

VOL. 127
Geographic
location Page

Okla. 791
N.Y., Ontario, 792

Minn., Wis.
Va. 793
Va. 794
Tenn., Va. 704
Tenn., Va. 7096
Ala. 797
Okla. 798
Ala., Tenn. 799
Okla. 801
Okla. 802
Pas 802
Nev. 803
Nev. 803
Tenn. 725
Va. 725
Okla. 727
Okla., Nev., 728

Tenn., Great

Basin
Va. 729
Tenn., Va. 730
Quebec 732
N. ¥.° Ve 664
Tenn. 665
Okla. 666
Ala. 210
Ala. 255
Va. 256

PART I

CHAZYAN AND RELATED BRACHIOPODS—-COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

Stenocamara bicostata Cooper

S. perplexa Cooper

Strophomena anomala Cooper

S. auburnensis Fenton

S. auburnensis impressa
Raasch

S. auburnensis nasuta Cooper

S. basilica Cooper
S. basilicoidea Cooper
S. bellilineata Cooper

S. billingsi Winchell and
Schuchert

S. canadensis Wilson

S. conradi Hall and Clarke

S. costellata Cooper

S. crinerensis Cooper
S. delicatula Fenton

S. dignata Fenton
S. exigua Fenton

S. fasciculata Cooper
S. filitexta obesa Wilson
S. grandimusculosa Cooper

S. grandis (Okulitch)
S. inconsueta Fenton
S. inspeciosa Willard

S. magna Wilson

S. medialis Butts

S. ? millionensts affinis
Wilson

S. minuta Wilson

S. mollis Wilson

S. musculosa Fenton

S. oklahomensis Cooper

S. okulitcht Cooper

SPECIES
Stage Formation
Marmor Mosheim
Marmor- Mosheim, Whistle
Ashby Creek, Ellett
Porterfield Benbolt
Wiiderness Auburn, Decorah
(Spechts Ferry,
Guttenberg)
Wilderness Platteville
Wilderness Carters, Tyrone
Wilderness Ridley
Porterfield Peery
Wilderness- Oranda, Martins-
Trenton burg (Salona)
Wilderness Chaumont-
Rockland
Wilderness Pamelia
Trenton Jacksonburg
Wilderness Bromide
(Pooleville)
Wilderness Bromide
(Pooleville)
Wilderness Barnhart, Plattin
(Macy), Zell
Wilderness Barnhart
Wilderness Plattin (Macy),
Zell
Porterfield Peery
Wilderness Rockland
Wilderness Lebanon, Dryden,
Ooltewah
Wilderness Lowville,
Chaumont
Wilderness Plattin (Macy),
Zell
Wilderness Wardell, Dryden,
Mahan
Wilderness Rockland
Wilderness Wardell, Dryden
Wilderness Chaumont-
Rockland
Wilderness Chaumont
Wilderness Chaumont
Trenton Decorah (Ion)
Wilderness Bromide
(Pooleville)
Wilderness Chaumont

Geographic
location

Ala.
Ala., Tenn.,
Va.

Va.

Mo., Ill., Wis.

Wis.

Ky., Tenn.
Tenn.

Wer

Va.

Ontario

Ontario
NEE
Okla.

Okla.
Mo.

Mo.
Mo.

Tenn.
Ontario
Tenn.

Quebec
Mo.

Ga., Tenn.,
Va.
Ontario
Tenn., Va.
Ontario

Ontario
Ontario
Minn.
Okla.

Quebec

183

Page
603
603

927
928
928
929
930
931
931
932
932
933
933
934
935

935
935

936

937
937

938
938
939
940
940
941
941
942
942
942

943

184 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species

S. planobesa Cooper

S. planumbona praecipta
Wilson
S. plattinensis Fenton

S. plattinensis crassa Raasch
S. platywmbona Cooper
S. rotunda Wilson

S. ? sculpturata Bassler

S. septata Winchell and
Schuchert
S. vernnstula Wilson

Strophomena sp. 1

Syndielasma biseptatum
Cooper

Taphrodonta parallela Cooper

Taphrorthis emarginata
Cooper
T. pecularis Cooper

Teratelasma neumani Cooper

Titanambonites amplus
(Raymond)

T. convexus Cooper
T. crassus (Willard)
T. medius Cooper

T. praecursor Cooper
Titanambonites sp. 1

Toquimia kirki Ulrich and
Cooper

SPECIES
Stage Formation
Porterfield- Murfreesboro,
Wilderness Ridley
Wilderness Chaumont
Wilderness Plattin (Macy),
Platteville
Wilderness Platteville
Wilderness Carters
Wilderness Chaumont-
Rockland
Trenton Martinsburg
(base)
Trenton Decorah (Ion)
Wilderness Chaumont-
Rockland
Wilderness Just beneath
Eureka quartzite
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Whiterock Upper Pogonip
(Rhysostrophia
zone)
Porterfield Arline, Little Oak
Porterfield Effna, Botetourt,
Pratt Ferry,
Rich Valley
Porterfield Sevier
Porterfield Pratt Ferry,
Arline, Little
Oak, Fetzer,
“Lenoir”
Porterfield Little Oak
Porterfield Effna
Porterfield Athens
Marmor Lenoir
Porterfield “TLenoir”-
Little Oak
Whiterock Upper Pogonip

(Rhysostrophia
zone)

VOL. 127
Geographic

location Page
Tenn. 943
Ontario 044
Mo., Wis. 045
Wis. 945
Ala. 945
Ontario 946
Pa. 946
Minn. 946
Ontario 946
Nev. 947
Nev. 743
Nev. 741
Tenn., Ala. 327
‘Ala, Wal. 328
Tenn. 824
Tenn., Ala. 718
Ala. 719
Va. 720
Tenn. 721
Tenn. 722
Ala. 723
Nev. 698

PART I

CHAZYAN AND RELATED BRACHIOPODS—-COOPER

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
Torynelasma minor Cooper
T. toryniferum Cooper

Trematis elliptopora Cooper
T. foerstet Cooper

T. huronensis Billings
T. minneapolis (Sardeson)

T. parva Cooper
T. ? spinosa Cooper
Trematis sp. 1

Trematis sp. 2
Trematis sp. 3

Trematorthis masoni Ulrich
and Cooper

T. robusta Cooper

T. tenuis Cooper

Trigrammaria trigonalis
prima Wilson
T. wilsonae Cooper

T. winchelli (Hall and Clarke)
Triplesia carinata Cooper
T. subcarinata Cooper

Triplesia sp. 1

Tropidothyris pentagona
Cooper

Undiferina rugosa Cooper

Valcourea angulata ( Phieger)
V. austrina Cooper

SPECIES
Stage Formation
Porterfield Pratt Ferry
Porterfield Pratt Ferry
Porterfield Pratt Ferry
Wilderness Plattin (Macy),
or Barnhart
Wilderness Black River
Wilderness Decorah
(Spechts Ferry)
Porterfield Whitesburg,
Chatham Hill
Porterfield Pratt Ferry
Porterfield Whitesburg
Porterfield Whitesburg
Porterfield Edinburg
(Cyrtonotella
zone)
Whiterock Upper Pogonip
(Orthidiella
zone)
Whiterock Upper Pogonip
(Orthidiella
zone)
Whiterock Upper Pogonip
(Orthidiella
zone)
Wilderness Chaumont
Wilderness Rockland
(Napanee)
Wilderness Platteville
Porterfield Pratt Ferry
Wilderness Lebanon
Porterfield Whitesburg
Porterfield Pratt Ferry
Porterfield Pratt Ferry
Ashby Barrel Spring
Ashby Whistle Creek,

Ellett

Geographic
location

Ala.
Ala.

Ala.
Mo.

Lake Huron
Minn.

Tenn., Va.
Ala.
Tenn.

Tenn.
Wer

Nev.

Nev.

Nev.

Quebec
Ney

Ill., Wis.,
Minn.

Ala.
Tenn.
Tenn.

Ala.

Ala.

Calif.
Var

185

Page
257
258

271
271

273
273
273
274
274

274
275

341

342

342

874
875
875
537
538

539

507

263

405
405

186 SMITHSONIAN MISCELLANEOUS COLLECTIONS

ANNOTATED LIST OF GENERA AND SPECIES—Continued

Species
V. brevicarinata Cooper
V. deckeri Cooper
V. intracarinata Ulrich and
Cooper
V. obscura Cooper
V. plana Cooper

V.. semicarinata Cooper

V. strophomenoides
(Raymond)

V.. tenuis Cooper

V.. transversa Cooper

V. ventro-carinata (Butts)
Valcourea sp. I
V alcourea sp. 2
V alcourea sp. 3
Valcourea sp. 4
Valcourea sp. 5

W estonia clathrata (Winchell
and Schuchert)

W. superba Cooper

W estonia sp. I

Xenambonites undosus Cooper

Zygospira circularis Cooper
Z. elongata Cooper

Z. lebanonensis Cooper

Z. ? matutina Cooper

Z. mediocostellata Cooper

Z. recurvirostris (Hall)

Z. variabilis Fenton and
Fenton

Zygospira sp. 1

Gen. and sp. undet.

SPECIES
Stage Formation
Porterfield Arline
Ashby Tulip Creek
Whiterock Upper Pogonip
Marmor Lenoir
Ashby or Yellow shaly Is. on
Porterfield 25’ ss., Eureka
group
Porterfield Arline
Marmor Crown Point
Ashby Tulip Creek
Porterfield Bromide
(Mountain Lake)
Porterfield Little Oak
Ashby Lincolnshire
Ashby Lincolnshire
Porterfield Red Knobs
Porterfield Arline
Ashby or Quebec City
Porterfield
Wilderness Decorah
(Guttenburg)
Porterfield Pratt Ferry
Porterfield Whitesburg
Porterfield Pratt Ferry
Wilderness Lebanon, Carters
Wilderness Lebanon,
Nealmont
Wilderness Lebanon, Barnhart,
Camp Nelson,
Moccasin
Porterfield Little Oak
Wilderness Sevier
Trenton Middle Trenton
Wilderness Plattin (Macy),
Zell
Wilderness Sevier
Porterfield Athens, Arline,

Pratt Ferry

VOL. 127
Geographic

location Page
Tenn. 406
Okla. 407
Nev. 408
Tenn. 409
Nev. 409
Va. 410
IND YS, Wits 4II
Okla. 412
Okla. 413
Ala. 414
Va. 415
Tenn. 415
Tenn. 415
Tenn. 416
Quebec 416
Minn. 209
Ala. 209
Tenn. 210
Ala. 815
Tenn. 670
Pa., Tenn. 670
Tenn., Mo., 671

Ky.

Ala. 672
Tenn. 672
N.Y. 673
Mo. 673
Tenn. 674
Ala., Tenn. 1006

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 187

Subclass GASTROCAULIA

Superfamily DicryoninaAcea Cooper, new superfamily

Small, transversely elliptical shells having a homoeodeltidium in pedicle valve
and a broad, open or partially closed notothyrium in the brachial valve.

Family MICROMITRIDAE Schuchert, 1929

Conservative corneous brachiopods with delthyrium more or less completely
closed by a homoeodeltidium.

The writer places in this family Micromitra, Dictyonina, and Dictyonites. The
structure of these genera is very similar, and it is no longer possible to assign
them to the Atremata. They cannot be assigned to the Palaeotremata because
Thompson defined that order as possessing calcareous shells.

According to Bell all the genera of the Paterinidae are in need of restudy. He
feels that some of them are polyphyletic, in which case family reassignments may
be necessary.

Dictyonites is unusual because it is essentially a Cambrian type of brachiopod,
having features that are among the earliest known in the brachiopods. The
family range is thus extended to the lower part of the Middle Ordovician.

DICTYONITES Cooper, new genus
(Greek dictyon, a net)

Semielliptical in outline ; valves hemiconical in profile, the pedicle valve form-
ing a fairly high cone; the brachial valve, a low cone; umbonal region of both
valves smooth and imperforate ; remainder of valves closely perforated by large
pores to form a fine meshwork (see discussion below).

Pedicle valve with moderately well formed but narrow pseudointerarea and
strongly arched homoeodeltidium. Pedicle interior with short median ridge at
apex. Brachial valve with narrow pseudointerarea and short, arched homo-
eochilidium. Traces of the musculature not seen in either valve.

Genotype.—Dictyonites perforata Cooper, new species.

Discussion.—Many features of this peculiar brachiopod are worthy of discus-
sion. The general aspect of the shell allies it with the Paterinacea, and the shell
itself is suggestive of the genus Dictyonina. It is quite unlikely that the shell
was perforated through its entire substance in life. Two of the specimens indi-
cate that an impervious outer layer was present, but its true nature cannot be
ascertained from the material at hand. Evidence points to the possibility that
the exterior was smooth or marked by concentric undulations. The reticulate
interior reminds one strongly of the deeply punctate inner shell surface of Jso-
gramma and Dictyonella.

Equally intriguing is the development of the umbonal region of both valves.
This consists of imperforate shell somewhat porcellaneous in appearance form-
ing a hemiconical apex. From the apex 2 low ridges diverge which separate 3
depressed areas. The anterior rim of the umbo is slightly protruding and from

188 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

it descends the fenestrate body of the shell. The brachial valve umbo is some-
what similarly constructed except for the fact that a median ridge divided a
shallow depression on each side.

DICTYONITES PERFORATA Cooper, new species
Plate 9, D, figures 11-13; plate 10, A, figures I-10

Shell small, semielliptical in outline with a straight hinge. Both valves hemi-
conical, the pedicle valve having the greater depth. Surface probably smooth or
marked by concentric undulations. Inner shell layer completely and densely
perforated.

Pedicle valve with narrowly rounded margins but broadly convex anterior
margin; lateral profile deeply concave anterior to the umbo but flattening some-
what anteriorly ; anterior profile conical with the apex of the cone surmounted
by the narrowly rounded umbonal and deltidial structures and the lateral slopes
steep and gently convex. Posterior margin narrowly rounded to the smooth and
somewhat inclined pseudointerarea sloping upward toward the homoeodeltidium.
Pseudointerarea triangular with the apex lying between the homoeodeltidium
and the main shell mass, marked by indistinct horizontal lines. Homoeodeltidium
strongly arched and elevated, deeply reentrant on its posterior edge and with
its sides tapering along the edge of the pseudointerarea. Umbo marked by 2
diverging ridges with depressed areas separating them and the homoeodeltidium.
Anterior margin of umbo defined by a slightly elevated and protruding ridge.
Interior with short septum in apex.

Brachial valve forming a low half cone; lateral profile gently concave ; anterior
profile flat but with the umbonal region elevated ; pseudointerarea very narrow;
sides somewhat narrowly rounded, anterior margin broadly rounded. Homoeo-
chilidium short, moderately strongly arched and with its sides extended along
the edge of the pseudointerarea as a low ridge. Umbonal region somewhat cres-
centic in outline with the convex side of the crescent facing anteriorly ; homoeo-
chilidium separated from the umbo by a horizontal ridge; umbo divided by a
triangular ridge with its apex pointing anteriorly ; ridge bounded by depressed
areas.

Measurements in mm.—

Length Width Thickness
Paratype (pedicle valve 116830f) ............. 2 2.4 1.0
A as. FUROR AEA inte ces Auer et 1.3 2.3 1.1
‘a (brachial valve 116830c) ........... 1.3 2.3 0.5

Types——Holotype: 116830-1; figured paratypes: 116830a-d,h-k; unfigured
paratypes: 116830e-g.

Horizon and locality—Lower 3 feet of the Pratt Ferry formation in Alabama:
0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This species is suggestive of some of the Cambrian forms referred
to Dictyonina or Micromitra, but the umbones of both valves are completely
unlike any known species of these or any other genera.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 189

Order ATREMATA Beecher, 1891

Superfamily OzsoLacea Schuchert, 1896
Family OBOLIDAE King, 1846

Obolacea with thickened and striated pedicle regions traversed by a pedicle
groove. Life habits as in modern Lingula.

Recovery of superb corneous brachiopod material by the use of acetic acid
has permitted a better understanding of some of the genera assigned to this
family. It is now clear that “Obolus” and “Lingula”’ are composite groups con-
sisting of many genera. Specimens recovered from the Pratt Ferry limestone
of Alabama permit wider identification of Lingulella. The type of that genus is an
Ordovician fossil, but the genus itself has been widely identified, probably cor-
rectly, in the Cambrian. A number of species herein described have the apical
characters of Lingulella and are so assigned. A number of others are tentatively
referred to this genus rather than Lingula because no Ordovician specimens
with the beak characters of Lingula were seen in the material herein described.

Subfamily OxsoLtinaAre Dall, 1870

Usually round or broadly oval forms with pedicle groove.

Genus OBOLUS Eichwald, 1829
OBOLUS ? BICONVEXA Cooper, new species
Plate 8, A, figures I-3

Shell small, broadly oval in outline with strongly curved margins; subequally
biconvex ; surface marked by concentric undulations. Pedicle valve moderately
convex but with the greatest convexity just anterior to the middle; anterior slope
short and steep. Anterior profile of pedicle valve broadly convex and with short,
steep lateral slopes and with median region swollen.

Brachial valve fairly strongly convex with the greatest convexity located in
the umbonal region and its vicinity ; anterior slope long and gentle ; anterior pro-
file moderately convex, somewhat narrowed medianly. Interiors unknown.

Measurements in mm.—

Length Width
Ftolarype (pedicle “valye):’ .s.. 2.0.0. inn vena ene os eee 5.9 5.4
Paritype, (orachtal valve TIG78ep) . 0). c date een. se 4.8 4.6

Types.—Holotype: 116788c; figured paratypes: 116788a,b.

Horizon and locality—lLower Paperville formation in Tennessee: On the
slope just south of the Southern RR. cut, 1 mile west of Mosheim, Mosheim
(T.V.A. 181-NW) Quadrangle.

Discussion—This species suggests O. nitens Cooper, new species, from a
similar position in the Rich Valley in a more western belt, but differs in the
lesser regularity of its ornamentation, the stronger biconvexity, and smaller size.

190 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

OBOLUS ? CYANE (Billings)

Lingula cyane Brtu1ncs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 216, fig. 200, 1865.—
Basser, U. S. Nat. Mus. Bull. 92, p. 862, 1915.

Horizon and locality—Table Head series (Logan’s Division P): 4 miles
northeast of Portland Creek, Newfoundland.

OBOLUS ? GRANDIS Cooper, new species
Plate 1, H, figures 26-28

Shell large and thick, suboval in outline and narrowly lenticular in profile.
Lateral margins moderately curved, anterior margin subsemicircular. Valves
subequally convex with the pedicle valve slightly deeper than the brachial one.
Greatest convexity of both valves at about the posterior third. Surface marked
by subequal concentric undulations which are a little more distinct and crowded
in the posterior half than at the front.

Pedicle valve with beak missing; umbonal and midregions swollen; lateral
slopes nearly flat in profile, sloping moderately to the margins. Slope from a
point one-third the length from beak faintly convex.

Brachial valve with beak having an apical angle of about 120° and protruding
posterior to the margin of valve junction. Midregion swollen for about two-
thirds the length from the beak. Anterior slope moderately steep, flat in profile.
Slopes to the lateral margins flat in profile, moderately steep.

Measurements in mm.—Holotype, length 42.7+, width 31.8, thickness 12.9.

Type.—Holotype: 71823.

Horizon and locality—Red Knobs formation, Tennessee: In a marble quarry
near Knoxville.

Discussion—This species may be distinguished by its large size and oval form.
Next to Ectenoglossa nymphoidea it is the largest of the linguloids known from
these rocks. It differs from all other species of Obolus in its great size.

OBOLUS ? NITENS Cooper, new species
Plate 7, C, figures 17-19

Shell small, broadly oval in outline. Brachial valve nearly circular. Sides and
anterior margin strongly rounded; posterolateral margins straight, forming a
beak angle of 100°. Surface marked by strong, even, elevated, fairly closely
crowded concentric lines.

Pedicle valve gently but unevenly convex in lateral profile. Strongest con-
vexity in the umbonal region from which a long, gentle slope extends to the
anterior margin. Anterior profile with low convexity but stronger than in the
other view. Pedicle valve somewhat humped-up in the middle with long, mod-
erately steep lateral slopes. Umbonal region and median two-thirds slightly
swollen, most so posteriorly. Beak small and not protruding posterior to the
posterior margin.

Brachial valve in lateral profile with its maximum convexity in the posterior

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER I9I

or umbonal region. Anterior profile slightly less convex than that of pedicle valve
and not so noticeably elevated in the median region. Beak marginal and small.
Umbo and posterior third slightly swollen. Posterolateral margins and anterior
two-thirds somewhat flattened. Umbonal slopes short but moderately steep.

Measurements in mm.—

Length Width

Holotype :(brachialy valve): .iic.is A. «ssi deo entiona. eek 8.2 7.6
Paratype, (pedicle valve \100329e), 0.3 scas}eyoo ne sind + ve amdas 6.8 6.4
. (brachial valye Too320DN (os. swe o. eae aes 6.2 6.0

Types.—Holotype: 109329a; figured paratypes: 109329b,d; unfigured para-
types: 109329c,e-g.

Horizon and locality—Lower Rich Valley formation, Porterfield Quarry in
Virginia: 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This species is characterized by its small size, slightly oval out-
line, low convexity and depth of the valves. It differs from O. virginiensis in its
smaller size, even, concentric ornamentation without radial elements, and broader
beak angle. Specimens are fairly common in the thin-bedded Rich Valley
formation.

OBOLUS ? VIRGINIENSIS Cooper, new species
Plate 7, E, figures 20-22

Palaeoglossa belli Wittarp (not Billings), Bull. Mus. Comp. Zool., Harvard Coll., vol. 68,
No. 6, p. 255, 1928.

Shell large, moderately thick, oval in outline and with the greatest width lo-
cated just anterior to the middle; valves unequal in depth, the brachial being the
deeper. Surface marked by uneven and interrupted undulations. Umbonal region
and posterolateral areas marked by transverse rows of short, elongated pustules
or elevated dashes separated by short gashes. Rows of pustules extending
medianly to form a low chevron.

Pedicle valve oval in outline with the greatest width located at about three-
fifths the length from the beak ; lateral profile slightly convex and with the maxi-
mum depth near the middle; anterior third flattened; anterior profile fullest in
the median region and with short, moderately steep lateral slopes. Beak
angle 95°.

Brachial valve subcircular in outline and with all margins rounded. Beak
marginal; umbo and central portion of valve swollen. Lateral profile more
strongly convex than that of the pedicle valve; greatest convexity in the posterior
third. Posterolateral slopes moderately steep.

Measurements in mm.—

Length Width
Polerype (pemicle Valve). Fee vec crc nnmaeare shes 23.8-+ 20 +
Patatype ‘(brachial valve’ 1009395) 622 P29 0EH) GFP 18.7-+ 18.5-+-

Types.—Holotype: 109334; paratype: 109335.
Horizon and locality.—Effna limestone in Virginia: Lower part of McNutt
Quarry, 5 to 6 miles northeast of Ceres, Burkes Garden (15’) Quadrangle; on

Ig2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

road to Ceres near W. S. Waddles’ house, 8 miles southwest of Bland, Bland
County.

Red Knobs formation in Tennessee: Ross and Republic Quarry, 5 miles south-
east of Knoxville.

Discussion.—This species is based on two specimens from calcarenite lime-
stone at two localities. Both specimens show the chevron arrangement of the
elongate pustules in the umbonal region. Although both are exfoliated, details
of the interior are not clear. The species is not related to Lingula=Palaeoglossa
belli to which it was originally referred. The ornamentation distinguishes this
species from all other known American Obolus.

OBOLUS sp. 1
Plate 8, D, figures 9-11

Shell thin, of about medium size for the genus, transversely oval in outline.
Greatest width located about two-thirds the length from the beak. Sides strongly
rounded; anterior margin broadly rounded. Surface marked by fine, elevated
concentric lines of growth.

Pedicle valve bluntly pointed, the beak forming an angle of 110°. Lateral
profile very gently convex, maximum convexity located at the umbo. Anterior
slope gently arched and long. Anterior profile moderately convex with flat and
moderately steep lateral slopes. Umbonal and median regions swollen.

Brachial valve with outline similar to that of the pedicle valve but having a
blunter and more rounded beak; greatest depth in the umbonal region. Lateral
and anterior profiles gentle but similar to those of the pedicle valve.

Measurements in mm.—

Length Width
Pedicle valve (LIO7GGd ys vc sags ane cree gee ts os 10.8 10+
Brachial Valve CLIOZOOC) tess ces cores Soe ee see eee as 10.5 12.0

Figured specimens.—11678ga-c.
Horizon and locality—Upper Table Head series, Port-au-Port, Newfoundland.
Discussion.—This is a more transverse species than any described from
younger rocks.
OBOLUS sp. 2

Plate 22, F, figures 12, 13

Shell of about medium size for the genus, represented by a single brachial valve
showing the interior and a counterpart thereof. Outline triangular with gently
rounded sides and narrowly rounded anterolateral extremities. Anterior margin
straight. Interior showing pallial marks and some of the muscle marks. Margin
with fine depressions perpendicular to the shell margin; matrix along shell mar-
gin on sides and anterior with a discolored margin showing hairlike marks sug-
gesting setae.

Measurements in mm.—Length 10.8, midwidth 8.8, widest part at front margin
10.2.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 193

Figured specimens.—116790a,b.

Horizon and locality—Blackford formation (shale below the ““Mosheim” but
above the Knox dolomite) in Virginia: About 3 mile east of Rocky Point, Natu-
ral Bridge Special (15’) Quadrangle.

OBOLUS ? sp. 3
Plate 0, F, figure 16; plate 11, A, figure 1

Fragments of a large oboloid brachiopod occur infrequently in the debris from
the Pratt Ferry limestone which indicate a new species of this genus. The ex-
terior is characterized by strong, elevated, narrowly rounded and crowded con-
centric lines. Not enough details of the interior are preserved to permit definite
identification with Obolus.

Figured specimens.—116791a,b.

Horizon and locality.—Pratt Ferry limestone in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

OBOLUS ? sp. 4
Plate 9, H, figures 20-22; plate 11, D, figures 6-8

Fragments of an oboloid brachiopod taken from the residues resulting from
the solution of the Pratt Ferry limestone indicate a new genus. The specimens
have the usual oboloid outline, but the exterior is marked by rounded concentric
ridges arranged in quincunx. Where the ridges intersect, pits are formed which
are also arranged in quincunx. Inside the brachial valve is a short triangular
area like that of Obolus formed by a fold of the shell.

Figured specimens.—116792a-c.

Horizon and locality.—Pratt Ferry limestone in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

OBOLUS ? sp. 5

Plate 2, D, figures 10, 11

This is a large species, 16.1 mm. long by 12.5 mm. wide. The single speci-
men is rather broadly oval in outline with the greatest width at about the middle.
The greatest depth is in the posterior half. The ornamentation consists of nar-
rowly elevated, concentric, often somewhat wavy lines. The spaces between the
concentric lines are very narrow in the posterolateral slopes but widen as they
cross the median part of the valve where they are distant by a space slightly more
than the thickness of the concentric line. On the posteromedian region the dis-
tance between the concentric lines is greater in the posterior half than in the
anterior half.

Figured specimen.—1 16772.

Horizon and locality —Effna limestone in Virginia: In a pasture along Vir-
ginia State Highway 114, 11 miles east of the junction with Virginia State High-
way 311 near Haymakertown, Roanoke (15’) Quadrangle.

194 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PSEUDOBOLUS Cooper, new genus
(Greek pseudes, false)

Shells attaining a length of about an inch, oval in outline; subequally biconvex,
the brachial valve having the greater convexity; pedicle beak elongated, in-
curved. Greatest width in anterior third. Surface marked by concentric undu-
lations and lines of growth. Interiors delicately marked by muscular and other
impressions, but none could be identified as particular scars. Muscle platforms
and septa wanting.

Genotype.—Palaeoglossa gibbosa Willard (see below for reference).

Discussion.—It is not usually wise to propose a genus for a species that does
not reveal its internal characters because of the delicacy of their preservation,
but this negative fact combined with a peculiar exterior may lend value to the
genus. Pseudobolus in its attenuated beak and strongly convex valves is ex-
teriorly unlike Obolus. Furthermore, its somewhat elongate oval form is another
feature unlike Obolus. This form suggests assignment to Palaeoglossa, but
reference to the type of that genus shows a fairly characteristic linguloid with
somewhat attenuated beak quite unlike that of the genus under discussion.
Furthermore, Lingula attenuata, type of Palaeoglossa, is strongly convex but
is more like Lingula in its outline and presumably its profiles.

Pseudobolus in exterior form is more like Dinobolus or Eichwaldia. The
elongate beak and spacious, deep shells are reminders of the Trimerellidae, but
no muscle platforms are present in either valve. Pseudobolus differs from Eich-
waldia in not possessing the peculiar foramen so characteristic of that genus,
and the brachial valve is nonseptate.

A word about the shell structure of Pseudobolus is necessary to its under-
standing. The shell seems to be laminated, but the lamellae are short and strongly
oblique to the surface. The color is a dull whitish gray and not the usually lus-
trous and highly colored brown or black common to Obolus and closely related
shells.

PSEUDOBOLUS GIBBOSUS (Willard)

Plate 24, G, figures 26-31

Palaeoglossa gibbosa WiLtard, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 256,
pl. 1, fig. 3, 1928.

Four specimens of this species are known besides the original type specimen.
Only one is fairly well preserved ; it is a young individual but shows both valves
in contact. The form and beak features of this young specimen taken together
with the lack of detail in the interior of the other specimens suggest a new
generic stock.

The young specimen indicates a nearly equally biconvex shell with the brachial
valve having the greater depth. In outline the shell is ovoid with the greatest
width slightly anterior to the middle. Profile of pedicle valve gently convex;
umbo well rounded, but anteriorly toward the anterior margin the shell is
flattened perceptibly. Beak of pedicle valve long and slender and moderately
incurved over the brachial beak.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 195

Brachial valve more strongly convex than the pedicle valve and with the great-
est convexity slightly posterior to the middle. Beak narrow and prominent ;
umbo swollen. Anteriorly the convexity becomes less.

Measurements in mm.—Hypotype 109422a, length 13.3, width 9.3, greatest
width 10.5, thickness 5; hypotype 109422b, length 23.9, greatest width 22.1.

The proportions of the larger specimens agree with those of Dr. Willard’s
type specimen.

Types.—Holotype: M.C.Z. 8587; figured hypotypes: 109422a,b; unfigured
hypotypes: 109422c,d.

Horizon and locality—Murat formation in Virginia: 2 miles northwest of
Lexington, Lexington (15’) Quadrangle.

PSEUDOBOLUS sp. 1

A single valve of another species occurs in the collection. The specimen is
subtriangular in outline, chalky grayish white in color. The surface is smooth
except for 4 deep concentric grooves representing resting stages of growth.
Greatest width in anterior third. The lateral profile is moderately convex with
the greatest curvature at the umbo. Anterior profile is broadly convex with a
flattened median region and short but steep lateral slopes.

Measurements in mm.—Length 15.6, midwidth 12.5, greatest width 16.

Described specimen.—109421.

Horizon and locality —Effna formation in Virginia: In the lower part of the
McNutt Quarry, 12 miles south of Bland, Burkes Garden (15’) Quadrangle.

Discussion.—This species differs from adult P. gibbosus by its plaited exterior
and more attenuate form.

Subfamily LINGULELLINAE Schuchert, 1893

Elongate and narrowly oval oboloids with pedicle groove; brachial valve with
concave, transversely striated apical plate.

Until recently it has not been possible to distinguish the true generic charac-
ters of most of the early and middle Ordovician linguloids. The etched material
from Pratt Ferry has permitted a good look at the hinge structures, but the
muscle arrangements are still to be worked out. The type species of Lingulella
comes from the Ordovician. Most of the species referred here to Lingulella have
not revealed their hinge structures. It is believed to be sounder to refer all these
to Lingulella, which is an Ordovician genus, rather than to call them Lingula,
which is a recent genus.

Genus LINGULELLA Salter, 1866
LINGULELLA ALABAMENSIS Cooper, new species
Plate 8, E, figures 12, 13

Shell small for the genus, brown to yellow-brown in color, widely oval in out-
line and with the greatest shell width anterior to the middle. Pedicle valve with

196 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

an apical angle of 70° to 80°; posterolateral margins straight; lateral margins
moderately strongly curved and gradually passing into the broadly curved an-
terior margin. Surface of both valves marked by elevated concentric lines crowded
on the lateral margins but more distant where they swing over the median parts
of the valves.

Pedicle valve with lateral profile gently convex and with maximum depth
slightly posterior to the middle; anterior slope long and gentle; anterior profile
fairly strongly convex.

Brachial valve less acuminate at the beak than the pedicle valve and with
gently rounded lateral margins; lateral profile flat medianly but with nearly equal
and gentle anterior and posterior slopes occupying the anterior and posterior
quarters. Umbonal and median regions somewhat swollen. Anterior profile
broadly curved.

Interior of pedicle valve with blisterlike, elongate triangular folds inside the
beak, the folds bounding a deep pedicle groove. Brachial valve with thickened
posterior margin and deep umbonal cavity and a long, low median ridge extend-
ing to about the middle.

Measurements in mm.—

Length Width Thickness
Holotype. (brachial valve). ocerenus - A-.simo asco 8.9 6.6 ?
Paratype (pedicle valve 1093092) ........... 10.7 7.6 1.0 ?
C Op. +, SEOOZOOR ) ls Hels teres 11.2 8.4 ?

Types.—Holotype: 1093094 ; figured paratype: 109309b; unfigured paratypes:
1093094,c.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—Lingulella alabamensis is characterized by having a widely oval
outline and somewhat attenuated beaks. It differs from L. lirata, which it resem-
bles, in its wider anterior region and more narrowly pointed beaks.

LINGULELLA BRAINERDI (Raymond)
Plate 3, D, figures 8-12

Lingula brainerdi Raymonp, Bull. Amer. Paleont., vol. 3, p. 36, pl. 18, figs. 2, 3, 1902; Ann.
Carnegie Mus., vol. 7, No. 2, p. 217, pl. 33, fig. 2, 1911.

Lingula limitaris SrELY (nom. nud.), Rep. State Geol. Vermont, n. s., vol. 1, p. 145, 1902;
vol. 5, p. 183, pl. 41, 1906.

Shell of moderate size for the genus, longer than wide; outline subpentagonal ;
apical angle about go°; lateral margins gently curved to nearly straight and
forming shoulders with the posterolateral margins. Anterolateral extremities
narrowly rounded to subangular; anterior margin gently rounded. Greatest
width located between the anterolateral angles and the posterolateral shoulders.
Ornamentation consisting of fine concentric growth lines and stronger, more
distant concentric undulations.

Pedicle valve gently convex in lateral profile with the greatest convexity about
one-third the length anterior to the beak. Valve full in the midregion but slop-

PART Wy CHAZYAN AND RELATED BRACHIOPODS—COOPER 197

ing gently to the anterior margin; anterior third flattened; slopes to lateral mar-
gins fairly steep in the posterior third but becoming gentle in the anterior third.

Brachial valve rounder in outline than the pedicle valve. Moderately convex
in lateral profile; fairly strongly rounded in anterior profile; posterior margin
obtuse, rounded, having an apical angle of about 110°. Beak blunt, reaching the
margin; umbo somewhat swollen; valve full for two-thirds the distance from
beak ; lateral slopes moderately steep.

Measurements in mm.—

Length Width Thickness
Hypotype (pedicle valve 109277a) .......... 21.4 13.9 ?
x Care eS EOQ277D) sere eee 20.7 14.5 ?
s (ees PPT OOZ77C) IS AER: 18.1 12.6 1.5
i Ces Teh woOpar7d) , . 523 0 18.8 14.4 ?
ff (brachial valve 109277e) ......... 14.8 10.0 2
¥ ae fm mOGoer Ey aii lees 2) i 16.8 12.1 2.0
: Girne? Beaty LOOZ 77S eevee is are 17.3 12.0 ?

Types.—Cotypes: Cornell Univ.; hypotype: Carnegie Mus. 5432; figured
hypotypes: 109277a,c,f,g; unfigured hypotypes: 109277b,d,e.

Horizon and locality.—Lower sandstone of the Chazy group in New York:
At Valcour Island, and Crown Point, Plattsburg (15’) Quadrangle. In Ver-
mont: On South Hero and Isle La Motte, Rouses Point (15’) Quadrangle.

Discussion.—This species is characterized by its subpentagonal outline with
greatest width near the anterior margin and the gently curved anterior margin.
The latter feature gives the valves an appearance of possessing a truncated an-
terior, but in fact it is broadly curved.

An attempt was made to determine internal features by dissolving the shell
away from its matrix. Although some good impressions of the exterior were
obtained, the internal features are not sufficiently distinct or well-enough pre-
served to leave traces on the sandstone. Fine radial lines appear on the inside
of exfoliated specimens of both valves and the casts of interiors. Such lines are
common in many linguloid shells and may be the impressions of setae.

A few immature specimens indicate that L. brainerdi is a somewhat longer
and more slender shell in its early maturity. The valves at that time are pro-
portionately longer and the outline more rounded and elliptical. The greatest
width remains in the anterior third, but it is by no means so pronounced as in
the older shells.

Lingulella brainerdi differs from L. huronensis Billings in its proportions, the
location of the greatest width near the front rather than near the middle, and in
having the greater height in the posterior third. Pseudolingula lutirellensis
Cooper, new species, has a pentagonal form similar to that of L. brainerdi but
is proportionally wider and has a much flatter shell.

LINGULELLA ? CLOCHENSIS (Foerste)
Lingula clochensis Forrste, Bull. Sci. Lab., Denison Univ., vol. 17, p. 253, pl. 2, figs. 11a, 11b,
1914.
Types.—Holotype: G.S.C. 8403; paratype: G.S.C. 84038.
Horizon and locality —Lowville”’ formation, La Cloche Peninsula, Ontario.

198 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

LINGULELLA COLUMBA (Raymond)

Lingula columba RAymMonp, Amer. Journ. Sci., ser. 4, vol. 20, p. 368, 1905; Ann. Carnegie
Mus., vol. 7, No. 2, p. 218, pl. 33, figs. 3, 4, IQTI.

Horizon and locality.—Chazyan limestone, Valcour Island and Chazy, Platts-
burg (15’) Quadrangle, N. Y.; and Isle La Motte, Rouses Point (15’) Quad-
rangle, Vt.

LINGULELLA DECORTICATA Cooper, new species
Plate 9, E, figures 14, 15

Shell thin, small for the genus; length about 14 times the width; sides gently
convex, subparallel; anterior margin broadly rounded; anterolateral extremities
narrowly rounded ; apical angle about 85° ; posterolateral margins nearly straight
and forming indistinct shoulders at about one-fifth the length from the beak.
Greatest width at about the middle. Surface marked by fine, crowded concentric
lines.

Pedicle valve with fairly evenly but gently convex lateral profile; unbonal re-
gion slightly the more convex part of the valve; anterior slope long and gentle;
anterior profile moderately convex.

Brachial valve slightly more convex than the pedicle valve and with broadly
rounded posterior margin. Beak small, protruding slightly posterior to the mar-
gin; lateral profile most convex at about the middle; anterior profile more con-
vex than that of the pedicle valve; somewhat swollen in the medial region with
moderately long and steep lateral slopes.

Measurements in mm.—Length 11.2, width 7.3.

Type.—Holotype: 116757.

Horizon and locality—Elway formation in Virginia: 4 mile east of Belfast
Mill, Saltville (T.V.A. 212-NE) Quadrangle.

Discussion.—This species differs from L. lirata in having a less attenuated
posterior.

LINGULELLA ENDOPUNCTATA Cooper, new species
Plate 8, G, figures 15, 16

Shell small for the genus, lustrous dark brown to black in color ; longitudinally
elliptical in outline with rounded lateral margins, narrowly rounded anterior and
bluntly pointed posterior extremities. Brachial valve deepest slightly posterior
to the middle, with a moderately steep and short posterior slope but with a longer,
convex but gentle anterior slope. Moderately strongly convex in anterior profile ;
umbonal region swollen; median region full; lateral slopes moderately steep.
Median elevation indistinct but present. Pedicle valves too poorly preserved for
description. Surface poorly preserved but the ornamentation consisting of more
or less distant concentric undulations.

Measurements in mm.—Holotype, length 7.3, width 4.5.

Types.—Holotype : 109320b; figured paratype: 109320a; unfigured paratypes:
109320c-e.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 199

Horizon and locality.—Botetourt formation (Cybeloides bed) in Virginia:
4 mile east of Strasburg Junction, Strasburg (15’) Quadrangle.

Discussion.—This small species is characterized by its lustrous black color,
strong convexity, and narrowly oval form. It suggests Elliptoglossa in outline
but is much more convex. It is not close to any other described Ordovician species
of Lingulella.

LINGULELLA FOSTERMONTENSIS (Butts)
Plate 1, E, figures 13-18; plate 10, D, figures 18-22

Lingula fostermontensis Butts, Alabama Geol. Surv., Special Rep. 14, p. 108, pl. 22, figs. 11,

12, 1926.

Shell of medium size for the genus, subpentagonal to elongate oval in outline ; |
longer than wide with the greatest width at about the middle. Valves nearly
equal in depth; lateral margins subparallel; anterolateral extremities strongly
rounded; anterior margin only moderately rounded. Posterolateral and lateral
margins forming a distinct shoulder, particularly in young specimens. Color
dark brown. Surface marked by irregularly spaced concentric undulations crossed
by fine concentric wavy lines.

Pedicle valve with beak missing in all specimens; gently convex in lateral
profile but moderately convex in anterior profile. Full in midregion for two-
thirds the length and with moderately steep slopes at the posterior becoming gen-
tler anteriorly. Front third flattened.

Brachial valve having posterolateral shoulders prominent, flattened ; umbonal
region swollen but merging into the flattened front third. Lateral slopes steep
and abrupt to the flattened areas defining the shoulders. Beak protruding slightly
posterior to the posterior margin. Anterior slope gentle.

Measurements in mm.—

Length Width Thickness
Lectotype (bractial *valve) <..0......-...-5 ba 8.9 1.5
Paratype (pedicle valve 71490a) ........... 13.0+ 8.9 1.5
Hypotype( “ sa AT LO7Z5Oa IN Ae 20.8 12 Toy
és (brachial valve 116759b) ......... 18.5 10.8 1.3

Types.—Lectotype: 71490b; paratype: 71490a; figured hypotypes: 109284d,
116759a-c ; unfigured hypotypes: 109284a-c,e-f, 116759d-f.

Horizon and locality.—Attalla formation (Blackford facies), Alabama: West
base of Foster Mountain, 14 miles northwest of Clay, Jefferson County, Leeds
(15’) Quadrangle.

Discussion.—This species is characterized by its solid form, fairly prominent
posterolateral shoulders, strong concentric undulations covered by fine concentric
but wavy lines. In shape it suggests Lingulella brainerdi Raymond and Pseudo-
lingula luttrellensis Cooper, new species, but both of these have less distinct
shoulders on the brachial valve.

200 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

LINGULELLA GALBA Cooper, new species
Plate 7, B, figures 13-16

Color orange-yellow ; valves oval in outline with the greatest width slightly
anterior to the middle. Lateral margins gently rounded. Anterolateral and an-
terior margins forming a semicircle. Beak of pedicle valve acute, apical angle,
about 70°. Surface of both valves marked by concentric undulations crowded at
the margins but more spread-out in the median region.

Pedicle valve: Lateral profile gently convex ; anterior profile moderately con-
vex. Umbonal region narrowly rounded and with steep slopes to the margins.

Brachial valve: Both profiles gently convex and having greater convexity than
the pedicle ones. Midregion moderately swollen; anterior slope gentle; slopes
to lateral margins moderate.

Measurements in mm.—

Length Width Thickness
Halotype’ (gediclé "valvey "occ es'ceae sce hs ce os 12.0 8.5 Pe
Paratype (brachial valve 109282a) .......... 10.4 8.2 1.8

Types.—Holotype: 109282b; figured paratype: 109282a ; unfigured paratypes:
109282c-g.

Horizon and locality—Bromide formation (Mountain Lake member), in
Oklahoma: Middle of east line sec. 33, T. 2 S., R. 2 E., 2 miles east of Springer,
Carter County.

Discussion—This species suggests the exfoliated Spinilingula intralamellata
Cooper, new species, but that is a much smaller species with stronger and more
distant concentric lamellae, and external spines.

LINGULELLA ? GLYPTA Cooper, new species
Plate 1, G, figures 21-25

Represented by two specimens of longitudinally elliptical outline; brachial
valve slightly deeper than the pedicle valve. Color light grayish brown. Sides
subparallel, gently curved. Anterior margin narrowly rounded. Median and lat-
eral areas differently sculptured, the former by irregular concentric undulations
which disappear on the flanks. Sides marked by striae closely crowded on the
lateral slopes near the margins but extending obliquely over the concentric undu-
lations on the lateral slopes near the junction with the median region.

Pedicle beak broken ; lateral profile gently convex with the most elevated part
at about the middle; anterior profile more strongly convex and with moderately
steep lateral slopes. Brachial valve with moderately convex lateral profile, with
the greatest convexity slightly posterior to the middle; posterior slope short and
moderately steep; anterior slope long and gentle. Anterior profile moderately
convex and with moderately steep lateral slopes. Incomplete dimensions in
mm. of holotype: length 11, width 6.5, thickness 2.9.

Types.—Holotype: 116760a; figured paratype: 11676ob.

Horizon and locality—Bromide formation (Pooleville member-zone 3) in

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 201

Oklahoma: At Rock Crossing of Hickory Creek, about center sec. 35, T. 5 S.,
R.1 E., Criner Hills, Carter County.

Discussion.—This species is characterized by the crowding of striae along the
sides and its long slender form. It differs from L. lirata Cooper, new species,
in its laterally confined striate ornamentation.

LINGULELLA HURONENSIS (Billings)

Lingula huronensis Bittincs, Canadian Nat. Geol., vol. 4, p. 433, fig. 9, 1859; Geol. Canada,
p. 124, fig. 48, 1863—RayMonp, Ann. Carnegie Mus., vol. 7, p. 219, 1911.—SINCLAIR,
Trans. Roy. Soc. Canada, ser. 3, vol. 30, sec. 4, p. 60, pl. 4, figs. 1-3, 1945.—WILSoN,
Geol. Surv. Canada, Bull. 8, p. 19, pl. 1, figs. 14, 15, 1946.

Types.—Lectotype: G.S.C. 1159; paratype: G.S.C. 11592.
Horizon and locahity.—Black River, St. Joseph Island, Lake Huron.

LINGULELLA ? HURONENSIS MINGANENSIS (Twenhofel and Whiting)
Lingula huronensis Bituncs, Canadian Nat. Geol., vol. 4, p. 433, fig. 9, 1859.
L. huronensis minganensis TWENHOFEL and WHITING, Geol. Soc. Amer. Special Pap. 11,
Pp. 44, pl. 7, fig. 15, 1938.

Type.—Holotype in Twenhofel Collection.

Horizon and locality.—Basal Mingan formation, Mingan Islands, St. Law-
rence River.

LINGULELLA KINGSTONENSIS (Billings)

Lingula kingstonensis Brttincs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 48, fig. 51
(adv. sheets, 1862), 1865; Geol. Canada, p. 141, fig. 74, 1863.

Types.—Lectotype (G. W. Sinclair, 1945): G.S.C. 1158; paratypes: G.S.C.
1158a-c,e,f.

Horizon and locality—Black River formation, near Long Island, near Kings-
ton, Ontario, Canada.

LINGULELLA LIRATA Cooper, new species
Plate 2, C, figures 8, 9; plate 5, H, figures 20-25; plate 6, D, figures 16, 17; plate 11, B,
figures 2-4; plate 28, F, figures 17-23

Lingula lyelli WiLLaRp (not Billings), Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 256, pl. 1, fig. 2, 1928.

Elongate oval in outline, length slightly less than twice the width; lateral mar-
gins very slightly convex and forming small shoulders where they join the pos-
terolateral margins. Beak forming an angle of about 80°. Surface marked by fine
elevated concentric lines which are crowded and prominent in the lateral and
posterolateral regions on the lateral slopes but indistinct on the median part of
the shell. Median region appearing smooth.

Pedicle valve deepest at a point about one-third the length from the beak;
anterior slope long and gentle; umbonal region narrowly swollen, the swelling
extending for the whole length but becoming gentler anteriorly ; anterior profile
moderately strongly convex. Posterolateral slopes short and steep.

202 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve with narrowly rounded posterior and anterior margins ; deepest
in the posterior third and with a long, gently convex anterior slope. Anterior
profile low and gently rounded. Median region from beak to anterior margin
gently swollen; lateral slopes short and moderately steep.

Measurements in mm.—

Length Width Thickness
Holotype ..is «. ARROBER CEA Poet 16.3 8.4 3.0
Paratype (pedicle valve 109332a) ........... 12.0 6.6 ?
- Om rs GARR Fe 4-0) RE OM 10.9 6.5 1.8
- (brachial valve 109332c) .......... 10.0 5.9 ?
. es “As TOOST AD) pita ae eter ef 16.0 0.3 4.4
- Corr, BM EL FOOO) | ec ra 0.2 6.2 1.5

Types—Holotype: 109317a; figured paratypes: 109317b, 109332a,b,
116761a,b, 117975a-c, 117980; unfigured paratypes: 109332c,d, 116761a,b,
117975d.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 miles south of
Pratt Ferry, Blocton (15’) Quadrangle.

Whitesburg formation in Tennessee: 2 miles southeast of Whitesburg, Bulls
Gap (T.V.A. 171-SE) Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: 1 mile northwest of
Lexington, Lexington (15’) Quadrangle.

Effna formation in Virginia: McNutt Quarry, 12 miles southwest of Bland,
Burkes Garden (15’) Quadrangle.

Discussion—This species is characterized by its moderate size, elongate-oval
outline, subparallel sides, and acutely angular beak. It is larger than L. decorti-
cata, new species, and with more parallel sides. Its elongate form distinguishes it
from L. galba, new species.

LINGULELLA MORSEI (N. H. Winchell)
Lingulepis morsensis N. H. Wi1NcHELL, 4th Ann. Rep. Geol. Nat. Hist. Surv. Minnesota,
p. 41, fig. 6, 1876.
Lingula morsei (N. H. Winchell) BAsster, U. S. Nat. Mus. Bull. 92, p. 731, 1915.

Horizon and locality——Upper part of the St. Peter sandstone in Minnesota:
Near Fountain, Fillmore County.

LINGULELLA NARRAWAYI (Wilson)

Lingula narrawayi Witson, Geol. Surv. Canada, Bull. 33, p. 49, pl. 3, figs. 4-6, 1921; idem,
Bull. 8, p. 19, pl. 1, figs. 10, 11, 1946.

Type.—Holotype in Royal Ontario Museum, Toronto.

Horizon and locality —Lowville formation, Parkdale Avenue, Ottawa, Canada ;
also reported from Pamelia formation at Aylmer and Hull in Quebec and at
Ottawa, Ontario.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 203

LINGULELLA RIDEAUENSIS Cooper, new species
Plate 5,1, figures 26-31

Shell thin, of about medium size for the genus, oval in outline, dark brown
or black in color. Beak pointed, posterolateral margins straight and forming an
angle of about 90° with the beak. Widest slightly anterior to the middle. Lateral
margins broadly rounded; anterior margin gently rounded, forming narrowly
rounded anterolateral extremities. Valves subequal in depth. Surface marked
by unevenly spaced, elevated concentric lines crowded in the posterolateral re-
gions, more distant in the median area.

Pedicle valve unequally convex with the maximum depth at about the middle ;
anterior slope long and gentle; umbonal and median regions swollen; lateral
slopes moderately steep, short, extending anteriorly nearly to the anterolateral
margins.

Brachial valve swollen in the umbonal and median regions, the swelling ex-
tending anteriorly to a point anterior to the middle; lateral profile strongly ele-
vated in the median half, sloping in the posterior and anterior quarters ; anterior
slope short but fairly gentle. Anterior and posterior profiles broadly rounded
in the median region with short, moderately steep lateral slopes. Beak bluntly
pointed, not protruding posterior to the posterior margin.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle valve) ................6 13.5+ 10.6 1.0?
Paratype (brachial valve 109315a) ......... 15.6 12.0 ? 1.6?

Types.—Holotype: 109315c; figured paratypes: 109315a,b, 109324a,c; un-
figured paratypes: 109324b.

Horizon and locality—Aylmer formation (Rockcliffe member) in Canada:
Hogs Back on Rideau River south of Ottawa, Gloucester Township, Carleton
County, Ontario; 44 miles west of Ottawa, Ontario.

Discussion—This species is characterized by its thin shell, oval outline, and
exterior marked by concentric undulations only. It suggests L. brainerdi, but
that species generally attains a larger size than the Canadian species and is more
quadrate in outline. Lingulella? huronensis is of about the same size but is less
attenuated.

LINGULELLA RUGOSILINEA Cooper, new species
Plate 4, D, figures 14-16

Shell small, longer than wide, ovate in outline with gently convex lateral
margins. Anterior margin gently rounded; anterolateral extremities broadly
rounded. Pedicle beak bluntly pointed, forming an angle of about 100°. Beak
of brachial valve marginal, forming an angle of about 110°. Surface ornamented
by fine irregular radial striae between which are located fine concentric wrinkles
concave posteriorly and ending laterally against the striae. Radii lost near the
margins where wavy concentric lines make the ornament.

Measurements in mm.—Holotype, length 12.5, width 7.3.

204. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 45069a and counterpart 45069b; figured paratype: 45069c.

Horizon and locality—Aylmer formation (Rockcliffe member, black shale)
in Canada: Hogs Back, south of Ottawa, Gloucester Township, Carleton County,
Ontario.

Discussion—The ornamentation of this species is like that of Pseudolingula
sculptata from the Camp Nelson formation at High Bridge, Ky., but the latter is
a much larger species with relatively finer ornamentation.

LINGULELLA SPICATA Cooper, new species
Plate 7, D, figures 23, 24

Shell of small to medium size for the genus, brownish gray to dark brown in
color ; length 14 times the width, narrowly oval in outline with a strongly pointed
beak and broadly expanded anterior. Apical angle about 60°. Lateral margins
gently curved from the beak to the anterolateral margins which are narrowly
rounded ; anterior margin strongly curved. Surface marked by strong concentric,
elevated lines, crowded along the margins but not strongly elevated, faint on the
median areas.

Pedicle valve: Lateral profile gently convex with the greatest depth at about
the middle and with long, gentle anterior and posterior slopes. Posterior profile
narrowly rounded; anterior profile only gently rounded. Umbonal region nar-
rowly convex and with steep lateral slopes, the swelling continuing anteriorly to
a point slightly anterior to the middle; anterior third flattened.

Brachial valve: Brachial convexity about equal to that of the pedicle valve
but with the maximum depth slightly posterior to the middle; anterior profile
moderately convex, distinctly more so than that of the pedicle valve; posterior
profile less convex than that of the opposite valve; anterior slope gently convex,
long and moderately steep. Posterior margin narrowly rounded and with the
beak anterior to the posterior margin. Lateral margins very gently curved; an-
terolateral extremities narrowly rounded; anterior margin strongly curved.
Umbonal and median areas moderately strongly swollen.

Measurements in mm.—

Length Width
Helotype (pedicle valve). ois‘ sseiomeclathshtores ae hte es does 15.0 98
Paratype (brachial valve 100300 D)jsssie essere -yseies toe gay ws 10.5 7.4

Types.—Holotype : 109301a; figured paratype: 109301b; unfigured paratypes:
10930Ic,d.

Horizon and locality —Whitesburg formation in Tennessee: Railroad cut at
Summit Hill School, 1 mile southwest of Otes, Bulls Gap (T.V.A. 171-SE)
Quadrangle.

Discussion.—This species is characterized by the strongly acuminate pedicle
beak, in which respect it is reminiscent of the Cambrian Lingulepis. This species
is different from all others herein described in the acuminate character of the
beak.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 205

LINGULELLA SUBPARALLELA Cooper, new species
Plate 4, B, figures 5-8

Shell small, longitudinally narrowly elliptical ; lateral margins faintly rounded,
nearly parallel; anterior margin narrowly rounded. Beak of pedicle valve form-
ing approximately a right angle. Posterior margin of brachial valve narrowly
rounded. Surface marked by strong and irregular concentric undulations and
covered by very fine concentric, wavy lines.

Valves of unequal depth, the brachial valve having a slightly greater depth
than the pedicle valve. Valves deepest at the posterior but becoming shallower
toward the front. Lateral slopes moderately steep at the posterior and median
part of both valves but merging into the flattened anterior part.

Measurements in mm.—Holotype, length 7.5, width 2.8, thickness 1.5.

Type.—Holotype: 109295.

Horizon and locality —Effna formation in Virginia: 1 mile east of Tilson
Mill, 16 miles northeast of Marion, Nebo (T.V.A. 223-NW) Quadrangle.

Discussion.—This interesting little species suggests Lingula clathrata Win-
chell and Schuchert from the Decorah shale of Minnesota, but the Virginia shell
differs in its larger size and more elongate form, and in not possessing the pecu-
liar ornamentation of the Minnesota species which is referred to as Westonia.

LINGULELLA TENUITESTA Cooper, new species
Plate 1, F, figures 19, 20

Shell small, dark brown in color, oval in outline, biconvex, with thin shell.
Posterolateral margins nearly straight ; lateral margins convex ; widest at middle;
anterior margin gently convex. Beak of pedicle valve pointed, forming an angle
of 80°. Ornamentation consisting of very fine, closely crowded, elevated con-
centric lines, often irregular and discontinuous.

Pedicle valve gently convex in anterior and lateral profiles. Lateral profile
uneven with the greatest elevation slightly posterior to the middle; anterior
profile broadly and somewhat depressed convex. Beak bluntly pointed ; umbonal
region somewhat narrowly swollen. Posterolateral slopes moderately steep,
median slopes gentler than the posterolateral ones. Anterior slope long and
gentle.

Brachial valve with anterior and lateral profiles depressed convex. Lateral
slopes narrow and moderately steep; anterior slope long and gentle. Maximum
convexity of valve at about the middle which is somewhat flattened.

Measurements in mm.—
Length Width Thickness

Holotype, (pedicle valve): ais ois ssc a ssinys de ee 8.1 6.3 ?
Paratype (pedicle valve 109299c) ............. 9.8 6.6 ty
Ch (brachial valve 109299b) ........... 6.2+ 5.5 ?

Types.—Holotype: 109299a; figured paratype: 109299b; unfigured paratypes:
109299c, 109300a-}.

206 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality Columbiana formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—Small size and thin shell are the characteristics of this species.
It differs from L. lirata Cooper, new species, from the Pratt Ferry formation
from the same locality in size and shape.

LINGULELLA VIRGINIENSIS Cooper, new species
Plate 1, C, figures 4, 5

Shell small, yellowish brown in color, subovate in outline. Beak approxi-
mately a right angle ; lateral margins rounded ; anterior margin narrowly rounded.
Valves unequally convex, the brachial one having the greater convexity. Sur-
face ornamented by a few distant concentric lines and finer lines of growth.

Pedicle valve nearly flat in lateral profile but gently convex in anterior profile.
Slopes to the lateral margins steep at the posterior but becoming obsolete
anteriorly.

Brachial valve gently convex with the greatest convexity located slightly pos-
terior to the middle. Lateral slopes steep posteriorly where the valve is some-
what swollen medially, but becoming gentle anteriorly. Beak blunter than pedicle
one.

Measurements in mm.—Holotype (pedicle valve), length 6.8, brachial length
6.5, width 4.0, thickness of complete specimen 1.6.

Type.—Holotype: 109296.

Horizon and locality—‘Ottosee formation” (probably Benbolt) in Virginia:
1 mile west of Rye Cove, Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—The ornamentation will serve to distinguish this species before
any of its other features. The distant concentric lines are like those of Plecto-
glossa oklahomensis, but this is a smaller and narrower species.

LINGULELLA sp. 1
Plate 8, C, figures 6-8

Black in color, narrowly elliptical in outline, length twice the width; greatest
width at about the middle. Lateral margins gently curved, anterior and posterior
extremities rounded. Ornamentation poorly preserved. Brachial valve deepest
in the middle with long posterior and anterior slopes, the latter being the steeper.
Anterior and posterior profiles narrowly convex with steep lateral slopes.

Measurements in mm.—Length 18.3, width 8.9, thickness 2.4?

Figured specimens.—116769a,c.

Horizon and locality.—Dark limestone of Upper Pogonip group (Anomalor-
this zone) in Nevada: Ikes Canyon, east side of Toquima Range, Roberts Moun-
tains (1°) Quadrangle.

LINGULELLA sp. 2
Plate 5, B, figure 6

Shell large for the genus, as shown by a single brachial valve; elongate oval
in outline, length about 13 times the width. Maximum width slightly anterior

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 207

to the middle. Posterior bluntly pointed; lateral margins broadly rounded but
with a strongly rounded anterior margin. Gently convex in anterior and lateral
profile. Surface preserved in the posterolateral region where it is marked by
regular, fine, elevated concentric lines.

Measurements in mm.—Length 27.1, width 15.6, thickness 1.5?

Figured specitmen.—116771.

Horizon and locality—Oil Creek formation (60 feet above the basal sand)
in Oklahoma: Sec. 12, T. 3 S., R. 3 E., 13 miles northwest of Sylvan, Carter
County.

LINGULELLA ? sp. 3

Plate 8, H, figures 17, 18

Represented by a single brachial valve which is large for the genus, oval in
outline with the length about 14 times the width. Beak prominent, narrowly ele-
vated and protruding posterior to the posterior margin which is somewhat
broadly rounded. Ornamentation consisting of fine, crowded, faintly elevated
lines shown in 2 small patches preserved at the posterior on both sides of the beak.
Evidence of an elongated central muscle track is indicated on the exfoliated
specimen.

Measurements in mm.—Length 22.6, width 15.8.

Figured specitmen.—109312.

Horizon and locality—Little Oak formation in Alabama: 4 mile south of
Newala, Montevallo (15’) Quadrangle.

LINGULELLA ? sp. 4
Plate 5, A, figures 1-5

Fairly large for the genus, elongate elliptical in outline with nearly parallel
sides; valves subequally biconvex ; length twice the width. Surfaces badly ex-
foliated but a patch showing the exterior indicates elevated concentric lines as
the surface ornament. Brachial valve showing indications of a median ridge
extending nearly the full length.

Measurements in mm.—Length 16.3 (not complete), width 8.3, thickness 4.0.

Figured specimen.—109304.

Horizon and locality—Arline formation (middle to upper) in Tennessee: On
Sevierville Pike, 5 miles southeast of Knoxville, Knoxville (T.V.A. 147-NW)
Quadrangle.

LINGULELLA ? sp. 5
Plate 5, C, figures 7, 8

This also is an elongate species which measures 14.3 mm. in length by 7.7 mm.
in width. It may be related to or the same as Lingulella sp. 4 but seems a deeper
shell. The brachial valve is moderately deep and moderately convex in lateral
profile but is fairly strongly convex in anterior view. The surface is marked by
fairly regular concentric elevated lines, finer and more crowded on the sides than
on the median portion of the shell.

208 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Figured specitmen.—109307a.

Horizon and locality—Arline formation in Tennessee: North side of wagon
road in glade, 4 mile east of Friendsville, Concord (T.V.A. 138-SW) Quad-
rangle.

LINGULELLA sp. 6
Plate 2, B, figures 6, 7

About medium size for the genus, length about 14 times the width; sides
gently curved, subparallel; anterior margin broadly curved; anterolateral ex-
tremities somewhat narrowly curved; posterior margin forming an angle of
about 110°. Beak anterior to posterior margin. Surface with concentric, ele-
vated growth lines crowded on the posterolateral extremities but more distant
and somewhat more regularly spaced on the median region. Specimens somewhat
crushed, making it impossible to describe the profiles accurately. The two speci-
mens available are brachial valves.

Figured specimen.—109322.

Horizon and locality——Aylmer formation (Rockcliffe member) in Canada:
Aylmer, Province of Quebec.

LINGULELLA sp. 7
Plate 8, F, figure 14

Shell small for genus, shiny brown in color, represented by the pedicle valve
only. Outline oval, posterior end acutely angular, apical angle about 80°. Lateral
margins gently curved; anterior margin strongly and broadly curved; lateral
profile gently convex but with anterior and posterior profiles fairly strongly con-
vex. Umbonal region strongly convex with steep lateral slopes. Anterior slope
long and gentle, forming a broad depressed area in the anterior third. Greatest
width anterior to the middle. Surface marked by fine, elevated concentric lines
crowded along the sides but often indistinct on the median region.

Measurements in mm.—Length 5.9, width 4.3.

Figured specimen.—109298.

Horizon and locality—Dutchtown formation in Missouri: Geiser Quarry, 14
miles east of Dutchtown, Cape Girardeau (15’) Quadrangle.

LINGULELLA ? sp. 8
Plate o, B, figures 7, 8

Shell small, narrowly oval in outline and with the narrowest part at the pos-
terior ; anterior narrowly rounded ; surface marked by distant, elevated corruga-
tions. Interior with a median callosity.

Figured specimen.—116779.

Horizon and locality —Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

PART)'T CHAZYAN AND RELATED BRACHIOPODS—COOPER 209

Genus WESTONIA Walcott, 1901
WESTONIA CLATHRATA (Winchell and Schuchert)
Plate 1, A, figures 1, 2

Lingula clathrata WINCHELL and ScHucHERT, Geol. Minnesota, vol. 3, p. 345, pl. 20, fig. 42,
1803.

Shell small, thin, longitudinally elliptical in outline. Lateral margins broadly
rounded ; anterior margin narrowly rounded. Greatest width at the middle or
slightly anterior to the middle. Beak angle about 90°. Surface marked by strong
concentric undulations which are crossed by transverse, subparallel lines that
swing slightly posteriorly at the middle to form a broad and shallow V. Trans-
verse lines most prominent on the flanks and body of the shell in the posterior
two-thirds, the anterior third being marked by such lines only on the lateral
slopes.

Pedicle valve with umbonal and median region somewhat swollen; greatest
depth in the posterior third ; anterior slope long and gentle ; umbonal slopes short
and steep. Anterior profile gently convex.

Brachial valve somewhat more convex than the pedicle one in both profiles.
Lateral profile gently convex but anterior profile moderately arched ; beak mar-
ginal; lateral slopes fairly strong; anterior slope gentle.

Measurements in mm.—

Length Width
MECRLOUU Pe |CrACKIAl VaANVG)\ cc's 0. soit ceca ane dere Sees queue 3.6 2.0
Paratype’ (pedicle:walve"45546a)) 0. kA Pe ee 4.5 2.3+

Types.—Lectotype: 45546b; figured paratype: 45546a; unfigured paratypes:
45546c-l.

Horizon and locality—Decorah formation (Guttenberg member-Rhinidictya
bed) in Minnesota: At St. Paul.

Discussion.—This species is characterized by its small size and peculiar orna-
mentation. The transverse lines are fairly distant, about 4 to the millimeter on
the shell edge, and crowding only slightly medially. The posterior swing in the
lines is shallow and separates this species easily from the others here assigned
to this genus.

Details of the interior are so difficult to determine from the specimens availa-
ble that it is not possible to decide the type of hinge region in the two valves.

WESTONIA SUPERBA Cooper, new species

Plate 11, E, figures 9, 10

Shell of about medium size for the genus, known from the brachial valve only.
Elongate, oval in outline, sides diverging anteriorly, nearly straight; anterior
margin narrowly rounded. Beak and umbo smooth; remainder of valve marked
by concentric, narrowly rounded, low costellae, nearly parallel on the margins
but swinging posteriorly to form a quincunxial pattern on the median region.
Strongly convex medially with long and moderately steep lateral slopes. Interior

210 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

like that of Lingulella. The largest specimen is incomplete but measures 6.5 mm.
in length and 5.2 mm. at its widest part.

Type.—Holotype: 116780b; unfigured paratypes: 116780a,¢c,d.

Horizon and locality Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

WESTONIA sp. 1
Plate 1, B, figure 3

Specimen incomplete, consisting of the posterior two-thirds of a brachial valve
with swollen median and umbonal regions and gently curved lateral margins.
Posterior profile somewhat narrowly convex and with fairly steep lateral slopes.
Surface, particularly the median region, marked by transverse regular undula-
tions forming a moderately deep V or chevron directed posteriorly in the median
region. The chevrons are cancellated by strong concentric undulations which
give the valve a pitted appearance in places.

Figured specimen.—116781a.

Horizon and locality—Lower part of Whitesburg formation in Tennessee:
Just above the Fetzer formation, on the slope 24 miles southeast of Whitesburg,
Bulls Gap (T.V.A. 171-SE) Quadrangle.

Discussion——Another specimen in the collection, 109355, is a crushed valve
having ornamentation similar to the above. The specimen was taken from the
lower Athens formation from the prolific Christiania beds, 25 miles southeast of
Riceville, Calhoun (T.V.A. 125-SW) Quadrangle, Tenn.

SPINILINGULA Cooper, new species
(Latin spina, a point)

Shells small to medium-sized, suboval in outline, biconvex, surface concentri-
cally lamellose, lamellae broad with short prone spines on their anterior margin.
Pedicle valve interior with deep pedicle groove bounded by two Dlisterlike,
elongate plates forming long umbonal cavities. Plates marked by narrow grooves
where they are attached to the side of the valve.

Brachial valve marked by a moderately long, undivided plate lying prone on
the posterior surface, anteriorly emarginate. Brachial valve also marked by a
faint median ridge, in adults extending from a point slightly posterior to the
middle to the anterior margin.

Genotype.—S pinilingula intralamellata Cooper, new species.

Discussion.—This genus is characterized by an interior like that of Lingulella
but with the exterior lamellose and spinose. It differs from other Lingulellinae
in its exterior features.

SPINILINGULA INTRALAMELLATA Cooper, new species
Plate 2, A, figures 1-5; plate 11, J, figures 25-32

Shell small, longer than wide, suboval in outline, with the greatest shell width
at about the middle. Apex acute forming an angle of about 70°. Lateral mar-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 2II

gins with nearly straight slopes from beak forming indistinct shoulder about
one-third length of valves from beak; lateral margins rounded ; anterior margin
gently rounded; anterolateral extremities narrowly rounded. Surface marked
by irregular concentric undulations that are crossed by irregular interrupted
radial lines which terminate in short, prone spines. Shell lamellae broad and
regularly spaced when seen on exfoliated specimens.

Pedicle valve very gently and evenly convex in lateral profile, broadly convex
in anterior profile. Greatest convexity slightly posterior to the middle. Anterior
slope gentle ; lateral slopes short, moderately steep.

Brachial valve evenly and gently convex in lateral profile, flattened to gently
convex in anterior profile. Umbonal region convex; anterior to umbo a broad,
shallow sulcus extending to anterior margin. Outer slopes of folds bounding
sulcus to lateral margins steep in posterior two-thirds but becoming gentle and
obsolete toward the anterior.

Measurements in mm.—

Length Width
Solotype. (bsachial, valve): 4: «xj. islam. | -caqulie. gett Be 3a 3.1
Paratype” (pedicle. valve 116783) .2006 000.2 o see ce eens 4.2 3.0

Types.—Holotype: 116784a; figured paratypes: 1og281a-e, 116784b-h; un-
figured paratypes : 116782a-i, 116783.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species is characterized by its ornamentation and small size.
The exfoliated shell shows regular concentric lamellae, distant and evenly spaced,
but well-preserved specimens show that the lamellae are covered by a surface
layer marked by concentric undulations and irregular radial lines terminating in
short spines. These features will serve to distinguish S. intralamellata from any
known linguloid from rocks herein treated.

The appearance of radial ornamentation arises from the fact that the lamellae
grow over the ends of the spines and therefore become wrinkled. This species
is abundant at the Pratt Ferry locality but has not been seen elsewhere. It can
be successfully etched from the limestone by acetic acid. Views of exfoliated
shells as well as etched specimens have been included because of the frequent
necessity of identifying specimens on fractured rock surfaces, which is the usual
way fossils are encountered.

Subfamily ACANTHAMBONIINAE Cooper, new subfamily
Subcircular shells with interior apical structures of both like Lingulella.
Exterior spiny.
ACANTHAMBONIA Cooper, new genus
(Greek acanthos, spine; ambon, umbo)
Shell minute, subcircular to suboval in outline; subequally biconvex ; surface

covered by minute, hairlike spines extending from the surface at a fairly high
angle.

212 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve with minute beak and broad apical angle; interior with narrow
propareas marked by concentric lines and appearing as narrow folds on the pos-
terior margin. Muscle marks so lightly impressed as to make it impossible to
determine the individual muscles. Pedicle groove poorly defined.

Brachial valve generally somewhat deeper than the pedicle valve and usu-
ally marked medially by a shallow sulcus. Umbo swollen; interior with some-
what thickened margin, incurved and with a posteriorly directed wave at the
beak which forms a notch. Muscle scars not deeply enough impressed to
distinguish.

Genotype—Acanthambonia minutissima Cooper, new species.

Discussion.—This genus is suggestive of Leptobolus but differs in the nature
of the posterior margins of both valves and the ornamentation. The spiny ex-
terior of Acanthambonia is a means of ready distinction between the two genera.
The apical structures of both valves are suggestive of Lingulella, but the exterior
is quite different. The genus is assigned to the Lingulellidae because the apical
structures are suggestive of that family. The general habit of Acanthambomia is
so different from that of the other Lingulellidae that the new subfamily is erected
for it.

ACANTHAMBONIA MINUTISSIMA Cooper, new species
Plate 18, D, figures 23-27

Shell minute, biconvex, the brachial valve having a slightly greater convexity
than the pedicle valve; beaks inconspicuous; outline nearly circular; surface,
including posterior margin, marked by fine hairlike spines, and faint concentric
lines of growth.

Pedicle valve moderately convex and with the greatest convexity located in
the posterior third; anterior slope gently convex and moderately steep. Anterior
profile fairly evenly and broadly convex ; beak small, protruding slightly posterior
to the posterior margin; umbo and median region inflated.

Brachial valve fairly strongly convex with the greatest convexity in the pos-
terior third ; anterior slope moderately long and gently convex, moderately steep ;
anterior profile swollen in the middle and with short and steep lateral slopes.
Median sulcus shallow, originating just anterior to the umbo and widening to
the front margin where it occupies about one-third the width.

Measurements in mm.—

Holotype "(pedidles yalvepioO.4 sr kiea4 be RRR tee 1.4 ng
Paratype. (brachial. yalve_ 1167954) #..jss20< sci eosjensis ations 1.6 1.4

Types.—Holotype: 116795b; figured paratypes: 116795a,c.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile south-
east of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species differs from A. virginiensis Cooper, new species,
which occurs at about the same level in Virginia, by its small size and more
scattered spines.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 213

ACANTHAMBONIA VIRGINIENSIS Cooper, new species
Plate 9, A, figures 1-6

Shell small, nearly circular in outline and with a small beak; surface marked
by crowded hairlike spines. Pedicle valve moderately convex in lateral profile
but with the greatest convexity located in the posterior third which is somewhat
swollen. Anterior slope long and gently convex. Umbonal region faintly carinate.
Anterior profile moderately convex, swollen in the middle with moderately steep
lateral slopes. Greatest width at the middle.

Brachial valve moderately convex in lateral profile but with the greatest depth
at the middle; median region swollen; lateral and anterior slopes fairly steep.

Measurements in mm.—

Length Width Thickness
Holotype (brachial valve) (05.10 ctt DUE 2.1 2.1 ?
Paratype (pedicle valve 116797a) ............ 2.7 3.5 0.6

Types.—Holotype: 116797e; figured paratypes: 116797a-d; unfigured para-
types : 116797f-h.

Horizon and locality.—Botetourt formation in Virginia: Field on the south
side of the road 0.2 mile east of Strasburg Junction, Strasburg (15’) Quadrangle.

Discussion.—This species was recovered in debris from the etching of lime-
stone blocks by hydrochloric acid. The species is suggestive of A. minutissima,
but it is a much larger shell with more numerous spines. The surface of A. vir-
giniensis is densely crowded with minute, delicate, and long spines. Furthermore,
the pedicle interior has more strongly developed propareas.

Subfamily GLOSSELLINAE Cooper, new subfamily

Elongate and narrowly oval oboloids with pedicle groove ; brachial valve with-
out concave apical plate, posterior margin more or less thickened.

Genus LEPTOBOLUS Hall, 1871
Plate 12, A, figures 1-4; plate 12, B, figures 5. 6

Shells small, oval in outline with subequally convex valves. Brachial valve
generally more convex and rounder in outline than the pedicle valve. Beak of
pedicle valve pointed. Surface of both valves ornamented by fine concentric
lines and, in one species, fine radial lines. Pedicle interior characterized by a
pedicle groove with narrow propareas on each side. Low median ridge anterior
to pedicle groove extending nearly to the middle where it forks narrowly, each
prong of the fork extending to about the middle of the valve and forming a shal-
low V-shaped chamber.

Brachial valve characterized by a complete posterior margin with small cal-
losity at the apex. Interior surface marked by 1 or 3 low ridges. Median ridge
the longer and extending nearly to the front margin where it is minutely forked.
Lateral ridges shorter than the median ridge and not present in all species,
diverging toward the anterolateral margin.

214 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion—The genus Leptobolus has been widely identified, but no un-
equivocal species of the genus has been found in the rocks treated in this mono-
graph. A small brachiopod having the exterior form of Leptobolus occurs in
the Liberty Hall facies of Virginia, but it fails to show the characteristic septa
in either valve. The best-preserved and unquestionable members of the genus
occur in Trenton-Cincinnatian rocks, but Reudemann described an unusually
large species, L. walcotti, from the Normanskill shale. According to his illus-
trations the brachial valve has a median septum. This, then, would probably
be the oldest member of the genus unless this part of the Normanskill should
prove to be of the same age as Trenton sedimentation.

Elliptoglossa has been confused with Leptobolus, but even casual examination
of the interiors should obviate confusion. Actually the exterior form and orna-
mentation of the two genera are quite different, but examination of the interior
details will settle the generic identity. Elliptoglossa is one of the peculiar brachio-
pods not provided with a pedicle groove, and no species has yet been found that
has septa like those of Lepiobolus.

LEPTOBOLUS WALCOTTI Ruedemann
Leptobolus walcotti RUEDEMANN, New York State Mus. Bull. 42, p. 560, pl. 1, figs. 6-12, 1901.

Horizon and locality—Normanskill shale in New York: At Kenwood and
Glenmont near Albany; Mount Merino near Hudson.

LEPTOBOLUS ? sp. 1
Plate 12, C, figures 7, 8

Shells minute, oval in outline with the greatest width anterior to the middle.
Pedicle valve nearly flat to very gently convex in lateral profile, gently convex
in anterior profile. Brachial valve unevenly convex with the greatest convexity
in the unbonal region. Anterior profile moderately convex. Umbonal and median
regions swollen ; anterior and lateral slopes gentle. Surface of both valves marked
by distant growth lamellae and fine concentric lines. Details of the interior
obscure.

Figured specimens.—109344a,b.

Horizon and locality—Edinburg formation (Liberty Hall facies) in Virginia:
Middle River north-northeast of Staunton, Staunton (15’) Quadrangle.

LEPTOBOLUS ? sp. 2

Two specimens from the upper 40 feet of the Edinburg limestone in the sec-
tion 4 mile west of Strasburg are larger than the above, and the exterior is orna-
mented by distinct and numerous radial wrinkles as well as fine concentric lines.
No details of the interior can be distinguished.

Described specimens—1093438a,b.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 215

Genus PSEUDOLINGULA Mickwitz, 1909
PSEUDOLINGULA AQUILINA Sinclair
Pseudolingula aquilina StncLatr, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 60, pl. 1,
fig. 12, 1945.

Type.—Holotype: G.S.C. 1160.

Horizon and locality—Age uncertain; “either pre-Lowville Black River or
Chazy”; in green siliceous limestone 25 feet from the base of the Ordovician
section at a cliff halfway between Malbai and Cap a l’Aigle, Murray Bay, Quebec,
Canada.

PSEUDOLINGULA ? EVA (Billings)

Lingula eva Bittincs, Canadian Nat. Geol., vol. 6, p. 150, 1861—Br1Lt1ncs in Logan, Geol.
Canada, p. 141, fig. 73, 1863.

Pseudolingula ? eva (Billings) Srnciatr, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4,
p. 60, pl. 1, figs. 16, 17, 1945.

Lingulasma eva (Billings) Witson, Geol. Surv. Canada, Bull. 8, p. 21, pl. 1, figs. 21-23, 1946.

Types——Lectotype: (G. W. Sinclair, 1945) G.S.C. 1160a; paratype: G.S.C.
1160b.

Horizon and locality—Black River ? formation, Murray Bay, Quebec, Canada.

Discussion —This species was recently discussed by Sinclair and Wilson.
These authors assign it to different genera. Wilson’s remarks do not indicate
that the ornamentation of the holotype is like that of Lingulasma. No mention
is made of the beaded exterior so characteristic of that genus and the figures of
the type show only strong concentric undulations. A third specimen (G.S.C.
6325), assigned by Miss Wilson to this series, is by its ornamentation definitely
an example of Lingulasma. It is doubtful, however, that it belongs to the species
to which it is assigned.

PSEUDOLINGULA ? IMPERFECTA Cooper, new species
Plate 5, D, figures 9-11; plate 6, E, figures 18-22

Shell large for an Ordovician member of the genus, thin in substance, usually
light lustrous bluish gray to horn brown in color. Strongly and subequally bicon-
vex in anterior and lateral profiles, subelliptical to oval in outline. Posterolateral
margins widely divergent, nearly straight, forming somewhat narrow shoulders
where joining the lateral margins. Lateral margins very gently convex, sub-
parallel, abruptly joining the somewhat strongly convex anterior margin. Sur-
face marked by broad concentric undulations on the median portion of both
valves but narrowly convex and closely crowded on the lateral slopes. Orna-
mentation on lateral slopes often gently wavy and some of the lines discontinu-
ous and irregular in direction.

Pedicle valve with imperfect beak in all specimens examined. Brachial valve
with thickened and inflected posterior margin; beak protruding beyond the
posterior margin.

Measurements in mm.—Holotype, length 22.8+, width 19.6, thickness 8.2.

216 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype : 109303b ; figured paratypes : 109303d, 116762a,b ; unfigured
paratypes : 109303a,c, 116762c.

Horizon and locality—Bromide formation (Pooleville member-O-soplecia
gouldi zone) in Oklahoma: Rock Crossing of Hickory Creek, about center sec.
35, T.5 S., R. 1 E., Criner Hills, Carter County.

Discussion—No perfect specimens of this species are known although many
collections were taken from Rock Crossing, where it is frequent but not com-
mon. The two brachial beaks preserved are rather imperfect but indicate a thick-
ened inner band. The species is not like any other Pseudolingula herein
described.

PSEUDOLINGULA ? LUTTRELLENSIS Cooper, new species
Plate 1, D, figures 6-12

Shell substance thin, shell large but compressed; subpentagonal in outline.
Width equal to about three-fourths the length. Apical angle of the pedicle valve
104°. Posterolateral margins straight; posterolateral extremity somewhat nar-
rowly rounded; lateral margins very gently curved; anterolateral extremities
narrowly rounded and the anterior margin gently convex. Greatest width
slightly anterior to the middle. Surface marked by fine, wavy concentric lines,
stronger on the flanks than on the central portion, where they are very fine.

Pedicle valve very gently convex in both profiles, shallow. Anterior third
broadly sulcate; posterior two-thirds of valve slightly swollen and forming the
deepest part.

Brachial valve more convex than the pedicle one and with the median portion
of the posterior two-thirds swollen gently and moderately convex. The lateral
slopes to the margins are short and fairly steep but the posterior slope, occupy-
ing the anterior third is long and gentle. Posterior margin narrowly rounded.
Beak low, protruding slightly posterior to the posterior margin.

Measurements in mm.—

Length Width Thickness
Paratype (pedicle valve 109286a) ............ 20.5 15.2 ?
ik (brachial valve 109286c) .......... 19.3 15.0 1*

Types.—Holotype: 109286b; figured paratypes: 109286a,c.

Horizon and locality —Moccasin formation in Tennessee: Near Luttrell, Lut-
trell (T.V.A. 155-NW) Quadrangle.

Discussion.—The outline and compressed form of this species suggest affinity
with Lingulella brainerdi and P. ? eva. It differs from the former in having a
more beautiful and complex concentric ornamentation, a more obtusely angular
beak, and less abruptly rounded anterolateral extremities. Pseudolingula ? eva
has similar proportions to P. ? luttrellensis but is somewhat more acuminate
apically and more broadly rounded anteriorly.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 217

PSEUDOLINGULA PYXIDATA Sinclair

Pseudolingula pyxidata StncLair, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 59, pl. 1,
fig. IO, 1945.

Type.—Holotype: Private collection G. W. Sinclair.
Horizon and locality.—Black River?, Riviére Sault a la Puce, Montmorency
County, Quebec.

PSEUDOLINGULA ? SCULPTATA Cooper, new species
Plate 3, B, figures 2-5

Description based on a brachial valve which is moderately large, subovate in
outline and with alternate broad bands of gray and pale brown. Apical angle
about 80°; posterolateral margins forming an indistinct shoulder with lateral
margins which are gently rounded. Anterolateral extremities narrowly rounded ;
anterior margin gently rounded. Slightly convex in lateral and anterior profiles.
Surface marked by fine concentric undulations of growth crowded and wavy on
the flanks; on the body of the valve numerous radial striae break up the concen-
tric lines into fine elevated scallops.

Measurements in mm.—Holotype, length 19+, width 12.5.

Type.—Holotype: 45065.

Horizon and locality—Camp Nelson formation in Kentucky: Opposite the
railroad station at High Bridge, Harrodsburg (30’) Quadrangle.

Discussion—This species suggests P. ? luttrellensis in its size and form but
differs therefrom in the nature of the ornamentation. The latter species does not
have the numerous fine radial striae interrupting the concentric marks.

PSEUDOLINGULA sp. 1

Shell large, subrectangular in outline with nearly straight and parallel sides.
Beaks missing; surface distinctly marked. Posterolateral areas with strong
concentric undulations which broaden anteriorly to disappear in the anterior half
which is nearly smooth. Fine undulations appear between the stronger ones in
the posterolateral area. Interior of one valve with a strongly developed callosity.

Described specimen.—116773.

Horizon and locality Shippensburg formation (Pinesburg member-Nidulites
zone) in Maryland: On U. S. Highway 40 on the west side of Conococheague
Creek at Wilson, 7 miles west of Hagerstown, Williamsport (15’) Quadrangle.

Discussion.—The specimen is recorded here in the hope that others will look
for better material. Its ornamentation and the muscle callosity suggest a new
form.

Genus ECTENOGLOSSA Sinclair, 1945
ECTENOGLOSSA ? LYELLI (Billings)
Plate 3, C, figures 6, 7

Lingula lyelli Bittrncs, Canadian Nat. Geol., vol. 4, p. 348, figs. 1a-1d; p. 431, 1859.—
Bituincs in Logan, Geology of Canada, p. 124, fig. 49, 1863.

218 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Lingula lyelli Billings, RaymMonp, Ann. Carnegie Mus., vol. 7, No. 2, p. 218, pl. 33, fig. 5,
(fig. 6, doubtful), rorr.
Lingula lyelli Billings, Stnciatr, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 67, 1045.

Types.—Lectotype (G. W. Sinclair, 1945): G.S.C. 1027C; paratype: G.S.C.
1027,

Horizon and locality—Aylmer formation (Rockcliffe member), Allumette
Island, Ottawa River, Pontiac County, Ontario, Canada.

ECTENOGLOSSA NYMPHA (Billings)

Lingula nympha Biiirnes, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 214, fig. 198,
1865.—Am1, Ottawa Nat., vol. 8, p. 85, 1804.

Ectenoglossa nympha (Billings) Srnctatr, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4,
p. 64, pl. 2, figs. 3-6, 1945.

Types.—Lectotype (Sinclair, 1945): G.S.C. 553; paratype: G.S.C. 553.
Horizon and locality —Table Head series, Table Head, Newfoundland.

ECTENOGLOSSA NYMPHOIDEA Cooper, new species
Plate 2, E, figures 12-20; plate 6, B, figure 6

Lingula nympha Raymonp (not Billings), Bull. Mus. Comp. Zool., Harvard Coll., vol. 68,
No. 6, p. 293, pl. 1, fig. 1, 1928.

Shell large for the genus, length equal to about twice the width. Lateral mar-
gins gently curved; the greatest width located at about the middle. Anterior
margin narrowly rounded. Beak angle about 80°. Surface where preserved
marked by concentric lines.

Valves subequal in depth, moderately convex in profile with the greatest con-
vexity and depth located in the posterior third. Anterior profiles moderately
convex but with the top of the curve flattened. Anterior two-thirds flattened
and with long gentle slopes to the front margin. Lateral slopes steep in the pos-
terior third but becoming more gentle anteriorly.

Interior details difficult to determine but pedicle valve thickened slightly an-
terior to the middle and in a path extending anteriorly along the median portion
of the valve by the growth track of the large anterior muscles. Median ridge
present in the brachial valve.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle ‘valve), .'5."s 0's i. a: sus cas 51.3 26.7 3.0
Paratype (brachial valve 71822a) .......... 52.1 25.3 4.5
og Gig ff * UmggaBo), !2b)2,. athe 36.1 19.2 2.0?

Types.—Holotype: 109292d; figured paratypes: 71822a, 109289, 109292e,
109297a,b; unfigured paratypes : 71822b, 109292a-c,f ; figured specimens: 109293,
116778a.

Horizon and locality—Whitesburg formation in Tennessee: On Bulls Gap
(T.V.A. 171-SE) Quadrangle, under the Southern RR. bridge about 1,000 feet
east of the station at Bulls Gap; road cut # mile southeast of Whitehorn; rail-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 219

road cut at Summit Hill School 1 mile southwest of Otes; 14 miles northeast
of Bulls Gap; 14 miles west of Bulls Gap. Edinburg formation (Liberty Hall
facies) in Virginia: 300 feet west of Route 3, ? mile northeast of Nineveh, Win-
chester (15’) Quadrangle; opposite the bridge at Riverton; near Front Royal,
Front Royal (15’) Quadrangle.

Chatham Hill formation in Virginia: John Grayson Farm, 4 miles southwest
of Bland, Bland County.

Paperville formation in Virginia: 4 mile northwest of Hollins School, Roa-
noke (15’) Quadrangle.

Discussion.—This is one of the largest known species of linguloid, and the
recorded dimensions given above are not those of the largest specimens, but of
the most perfect ones. An imperfect individual from the Athens shale of White-
horn, Tenn., measures 69 mm. in length, but portions of the anterior and pos-
terior are missing, which would probably place the actual length in the neighbor-
hood of 75 mm., or 3 inches. The width of the specimen is 29 mm.

This species is most like E. nympha Billings from the Table Head formation
of Newfoundland but differs in being proportionally narrower and with less deep
valves. Billings’ species is 3 times as long as wide, and its sides are more parallel
than those of E. nymphoidea.

ECTENOGLOSSA ? RUBRA Cooper, new species
Plate 8,J, figures 21-26

Shell large, somewhat quadrate in outline. Lateral margins nearly parallel ;
anterolateral extremities narrowly rounded, anterior margin gently curved ; apex
obtusely angular. Surface marked by scattered concentric undulations and very
fine, concentric, closely crowded, wavy lines particularly on the median region.

Pedicle valve with greatest depth slightly posterior to the middle ; anterior and
posterior slopes gentle; anterior profile broadly convex, flattened in the median
area and with short moderately steep lateral slopes. Brachial valve somewhat
deeper than the pedicle valve but with similar profiles.

Measurements in mm.—

Length Width Thickness
TRIE VIDE ort c ct igs hee alone imepeide « hyaatsreninnes aabhh 36.2 20.2 5.0 ?
Pare CPEOZIID)) cx)=, cos-> a) dios wa abe hacen ee 21.2 16.8 9.2

Types.—Holotype: 116777a; figured paratype: 116777b; unfigured paratypes:
116777C¢,d.

Horizon and locality.—Base of the Bays formation in Tennessee: 14 miles
south-southeast of Houk, Loudon (30’) Quadrangle=o.15 mile northeast of
Fourmile Church, Tallassee (T.V.A. 139-SE) Quadrangle.

Discussion——This species is interesting because it occurs in red beds. It is
characterized by its deep and elongate valve. It is somewhat like E. nymphoidea
but is not so large and is differently ornamented. The finely crinkled lines are
quite distinctive.

220 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ECTENOGLOSSA ? SCULPTA Cooper, new species
Plate 4, C, figures 9-13

Shell fairly large, light bluish gray in color on the outer surface but with inner
layers grayish brown; outline longitudinally and narrowly elliptical; sides sub-
parallel, gently convex ; widest at about the middle; anterior narrowly rounded ;
posterior bluntly pointed but apical angle unknown; surface marked by closely
crowded, elevated concentric lines and ridges, most prominent on the lateral
slopes; concentric ornamentation crossed by fine radial striae which are most
prominent in the median region.

Pedicle valve slightly deeper than the brachial one; greatest depth at about
the middle with long, gentle anterior and posterior slopes; anterior profile fairly
strongly convex with moderately steep lateral slopes. Brachial valve with nar-
rowly rounded posterior margin; lateral profile flattened in the median half and
with the anterior and posterior quarters sloping to the extremities. Anterior pro-
file slightly less convex than that of the pedicle valve.

Measurements in mm.—Holotype, length 25.7, width 14.9, thickness 7.7.

Types.—Holotype: 109302b; figured paratype: 109302a; unfigured paratype:
109302c.

Horizon and locality—Bromide formation (Pooleville member-O xoplecia
gouldi zone) in Carter County, Okla.: Rock Crossing of Hickory Creek, about
center sec. 35, T. 5 S., R. 1 E., Criner Hills; on a branch of Hickory Creek in
NW43 sec. 26, T. 5 S., R. 1 E., Crier Hills.

Discussion.—This species is doubtfully referred to the genus Ectenoglossa
because of its long and slender form, but the “teeth” referred to by Sinclair,
author of the genus, were not seen. The species is further distinguished by the
radial elements on an otherwise Lingula-like ornament. It differs from E. nym-
phoidea by its more slender dimensions and details of the ornamentation.

ECTENOGLOSSA sp. 1
Plate 8, B, figures 4, 5

Shell thin, large for the genus, oval in outline, width about two-thirds the
length; posterior margin somewhat narrowly rounded; sides gently curved; an-
terior margin slightly more broadly rounded than the posterior margin. Great-
est width at the middle. Surface marked by fine concentric lines and broad con-
centric undulations.

Measurements in mm.—

Length Width
BOTANY Sada. eh e cprvehissts Tnsiss ova Pag eal a st dks + ea Sr ci 25.0+ 16.7
ATOZ ORE lM ale ncidis 5 leet len citys (age Ma nice LANE Te ROMER Tea cay sl 23.1 14.8

Figured specimens.—116776a,b.

Horizon and locality—Upper Table Head series, Port-au-Port, Newfound-
land.

Discussion—The two specimens (probably pedicle valves) in the collection

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 221

suggest relationship to E. nympha and E. nymphoidea, but they represent a
smaller shell than either of the two mentioned. Possibly the present specimens
represent young of the former, but this cannot be established in their partially
crushed state.

Genus PALAEOGLOSSA Cockerell, 1911
PALAEOGLOSSA ? BELLI (Billings)
Plate 7, F, figures 25-29
Lingula belli Birttncs, Canadian Nat. Geol. vol. 4, p. 431, figs. 7, 8, 1859; Geol. Surv.
Canada, 15th Rep. Progress, p. 124, figs. 47a, b, 1863.

Obolus belli (Billings) Watcott, U. S. Geol. Surv. Mon. 51, pt. 1, p. 386, pt. 2, pl. 38, figs.
3a, b, 1912.

Specimens referred to this species by Raymond are not here included in the
synonymy because the specimens are too badly damaged and are much smaller
in size. It is not now possible to place them properly; better material will be
needed for certain identification.

Types—Lectotype (Walcott, 1912, pt. 2, p. 130): G.S.C. 1026b; paratype:
G.S.C. 1026c; figured specimens: U.S.N.M. 109231a,b; Carnegie Mus. 5431.

Horizon and locality —St. Martin formation,Island of Montreal, Quebec; base
of Chazy group, Valcour Island, Lake Champlain, Plattsburg (15’) Quadrangle,
N.Y:

PALAEOGLOSSA MYSTICENSIS Cooper, new species
Plate 9, G, figures 17-19

Shell of about medium size for the genus, light gray in color, length approxi-
mately 14 times the width. Beak narrow; sides gently rounded and diverging
to the anterior margin which is narrowly rounded. Greatest width at a point a
short distance anterior to the middle. Lateral profile slightly convex; anterior
profile broadly convex but with moderately steep and short lateral slopes. In-
terior with long median ridge extending for about half the valve length.

Measurements in mm.—Holotype (estimated), length 11.5, width 7.6.

Types.—Holotype: 66285a ; figured paratypes : 66285b,c ; unfigured paratypes:
66285d-f.

Horizon and locality Mystic conglomerate in Quebec: Range 6, Lot 20, near
Mystic, Stanbridge Township.

Discussion.—This species is characterized by the long median septum in the
brachial valve, which is the only valve available for study. It differs from P. at-
tenuata, type of the genus, in its more slender form.

PALAEOGLOSSA ? PULICIS (Sinclair)
Lingula ? pulicis Stncuatr, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 68, pl. 2,
figs. 7-9, 1945.
Types.—Holotype and paratypes in private collection G. W. Sinclair.
Horizon and locality—Black River?, Riviére Sault 4 la Puce, Montmorency
County, Quebec.

222 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PALAEOGLOSSA sp. 1
Plate 10, C, figures 14-17

This is a large form, nearly twice as long as wide, with gently rounded sides
and broadly rounded anterior margin. Valves subequally convex. Pedicle valve
with apical angle of 95°. Brachial valve with broadly rounded posterior. Brachial
valve with long median ridge.

Measurements in mm.—116775, length 19.5, width 11.5, thickness 4.2.

Figured specimen.—116775.

Horizon and locality—Edinburg formation (Cyrtonotella zone) in Virginia:
100 yards west of U. S. Highway 11, 1 mile northeast of Strasburg, Strasburg
(15’) Quadrangle.

PLECTOGLOSSA Cooper, new genus
(Greek plektos, fold; glossa, tongue)

Oval in outline and lenticular in profile; brachial valve slightly deeper than
the pedicle valve. Pedicle beak acute. Surface marked by regular, elevated con-
centric lines.

Pedicle beak with a depressed pedicle plate marked medially by a low fold.
Posterior margin of brachial valve thickened as in Pachyglossa.

Genotype.—Plectoglossa oklahomensis Cooper, new species.

Discussion.—This genus is characterized by its oval outline and compressed
lenticular profile with regular, elevated concentric ridges. The interior of the
posterior margin of the brachial valve is like that of Pachyglossa, but the apical
features of the pedicle valve are unlike any other linguloid described herein in
having a concave apical plate marked medially by a low fold. The exterior form
and ornamentation of this genus suggest Trigonoglossa, but that genus differs
in having a more triangular outline, more compressed valves, and a different
type of pedicle plate. In Trigonoglossa this plate is deeply concave and lies close
to the floor of the valve. Furthermore, the sides are not marked by a ridge and
are much more narrowly folded.

PLECTOGLOSSA OKLAHOMENSIS Cooper, new species
Plate 6, C, figures 7-15

Shell small, grayish blue to black in color, oval in outline. Posterolateral mar-
gins straight, forming indistinct shoulders where they join the lateral margins at
about one-third the length from the beak. Greatest width at about the middle.
Lateral margins gently rounded; anterior margin strongly rounded. Surface
marked by distant, fairly evenly spaced raised concentric lines between which
occur irregular fine concentric lines. Young portions of valves at umbones dark
and smooth, marked only by fine concentric lines.

Pedicle valve with narrow beak; lateral profile moderately convex with the
greatest convexity near the middle; anterior slope long and gentle; anterior
profile fairly strongly convex and somewhat swollen medianly; lateral slopes

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 223

flat and moderately steep. Pedicle groove wide but marked medianly by a low
longitudinal swelling.

Brachial valve with beak protruding slightly posterior to the posterior margin ;
deeper than the pedicle valve with a moderately convex lateral profile ; anterior
profile broadly convex with moderately steep slopes; anterior slope long and
gentle.

Measurements in mm.—

Length Width Thickness
Paratype) Geo2o4 iro. Za. I. Bees. 11.2 7.6 1.8
es CBAGZES a SHAS vhs Tease bas ee 10.3-++ IF 3.0
3p CRG TGAD NOT: Misites to Soong REN ae 10.8 7h ?

Types.—Holotype: 116765 ; figured paratypes: 109294, 116763, 116764.

Horizon and locality—Bromide formation (Pooleville member-Oxoplecia
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek about center
of sec. 35, T. 5 S., R. 1 E., Criner Hills, Carter County; and on Spring Creek,
N3 sec. 17, T.2 S., R. 1 W., Murray County.

Discussion—In ornamentation this species suggests Lingulella virgimiensis,
but it differs in its more broadly oval form and greater size.

It is also suggestive of P. sp. 1 from Benbolt formation which has distant
elevated, concentric lines. The Benbolt species seems to have been a much
larger shell and with more distantly spaced concentric lines.

PLECTOGLOSSA sp. 1
Plate 8,I, figures 19, 20

This is a fragmentary specimen with imperfect beaks and with the anterior
third missing. The ornamentation, however, is very distinctive. The valves are
of subequal depth but with the brachial valve slightly the deeper. The umbonal
and median regions of this valve are somewhat swollen and have steeper lateral
slopes than those of the pedicle valve. The ornamentation consists of strong,
elevated concentric lines, crowded in the posterolateral areas but swinging apart
and subequally spaced on the median areas.

Figured specimen.—116774.

Horizon and locality—Benbolt formation in Virginia: 0.2 mile south of the
middle fork of Moccasin Creek, 14 miles south of Hansonville, Hansonville
(T.V.A. 205-SW) Quadrangle.

PACHYGLOSSA Cooper, new genus
(Greek pachys, thick; glossa, tongue)

Elongate elliptical in outline, strongly biconvex but the brachial valve generally
having the greater convexity. Shell usually thick. Surface marked only by
growth lines and concentric wrinkles.

Interior of pedicle valve with posterior structure like that of Lingulella with
a deep pedicle groove margined by concentrically marked thickenings. Posterior
margin of brachial valve slightly thickened and without a posterior plate.

224 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genotype.—Pachyglossa dorsiconvexa Cooper, new species.
Discussion—This genus is suggestive of Lingulella but differs in profile and
in the character of the posterior margin of the brachial valve. Pachyglossa is
usually strongly biconvex whereas Lingulella is generally flatly biconvex. The
interiors of the pedicle valves of both genera are similar but the posterior mar-
gins of the brachial valves are different. In Lingulella the posterior of the
brachial valve is occupied by a concentrically marked concave plate. In Pachy-
glossa, on the other hand, the posterior margin is unmodified and there is no
concave plate. The margin may be more or less thickened, but that is the only
modification detected. Other species assigned to this genus are P. biconvexa of
the Bromide of Oklahoma and P. pachydermata from the Effna formation of
Virginia.
PACHYGLOSSA BICONVEXA Cooper, new species
Plate 7, A, figures 1-12

Shell of about medium size for the genus, strongly biconvex in lateral profile,
elongate-oval in outline with the shell substance thick. Lateral margins broadly
curved with the greatest width slightly anterior to the middle. Anterior margin
somewhat narrowly rounded. Beak angle about 100°. Surface marked by fine
and strong concentric growth undulations.

Pedicle valve having the lateral profile unevenly convex with maximum con-
vexity slightly posterior to the middle; anterior profile somewhat narrowly
rounded, the elevation equal in height to about one-quarter the width. Beak not
conspicuous but meeting the margin. Umbonal region slightly swollen, the swell-
ing continuing to a point slightly anterior to the middle. Posterolateral slopes
steep but anterior slope long and only moderately steep.

Brachial valve having profiles similar to those of the pedicle valve but more
convex. Posterior margin broadly rounded and only slightly narrower than
the anterior margin. Umbonal region narrowly convex and the median portion
of the valve conspicuously swollen and with slopes similar to those of the pedicle
valve.

Measurements in mm.—

Length Width Thickness
Paratype (pedicle valve 109269a) .......... Ti 11.8 28
+ (brachial valve 109260b) ......... 13.7 10.6 2.9

ia Te BOOZ 7 TY aot ois as 15.9 II.4 2.8?

Types——Holotype: 109271g; figured paratypes: 109269a, 109271f,j,m; un-
figured paratypes: 109269b, 109271a-e,h,i,k,].

Horizon and locality—Bromide formation (Pooleville member-O-oplecia
gouldi zone) in Oklahoma: At Rock Crossing over Hickory Creek, about cen-
ter sec. 35, 1.5 S., R. 1 E., Criner Hills, Carter County ; on a branch of Hickory
Creek in NW34 sec. 26, T. 5 S., R. 1 E., Criner Hills west of Overbrook, Criner
Hills, Carter County.

Discussion—This species is characterized by the nearly equal and strong con-
vexity of both valves in the median region. In this respect it differs from P. ?

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 225

eldert which it somewhat resembles. The shell of P. biconvexa is unusually
thick and shows some marks of the internal structure. Unfortunately the speci-
mens which showed these marks were prepared by burning the shell in a blast
lamp and then flaking off with a needle. The details obtained are not sufficiently
clear to make an adequate description of the interior.

PACHYGLOSSA DORSICONVEXA Cooper, new species
Plate 11, F, figure 11; plate 28, C, figures 7, 8

Shell small, brown to blue-gray in color, elliptical in outline with the length
slightly greater than the width ; greatest width at the middle. Pedicle valve with
the posterolateral margins nearly straight and forming an apical angle of about
80° ; sides gently rounded ; anterior margin narrowly rounded ; pedicle valve with
lateral profile gently convex and with the greatest convexity at about the middle ;
anterior and posterior slopes gentle ; anterior profile moderately convex. Pedicle
interior with deep pedicle groove between lateral folds.

Brachial valve with subequally rounded extremities and gently rounded sides ;
lateral profile strongly convex; greatest depth about one-third the length from
the beak; anterior slope long and gentle; anterior profile somewhat narrowly
rounded and with steep lateral slopes. Beak marginal. Surface of both valves
marked by irregular, strong concentric undulations.

Brachial interior with thickened posterior margin which is not inflected.
Muscle pattern not clear.

Measurements in mm.—Holotype, length 7.2, width 5.0, thickness 1.8?

Types.—Holotype: 116758a; figured paratype: 117976; unfigured paratypes :
116758b-g, 117976a-f.

Horizon and locality —FPratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This species in its strongly convex and elliptical brachial valve
strongly suggests a small P. biconvexa from the Bromide of Oklahoma. The
colors are also similar. Nevertheless, the species are different. The Oklahoma
one is much larger, and the brachial valve is proportionally less convex.

PACHYGLOSSA ? ELDERI (Whitfield)
Plate 5, E, figures 12-14

Lingula elderi WuitrieLp, Amer. Journ. Sci., ser. 3, vol. 19, p. 472, figs. 1, 2, 1880. For
further synonymy see Bassler, U. S. Nat. Mus. Bull. 92, p. 728, 1915.

Figured specimens.—24734a, 45015a.
Horizon and locality.—Platteville limestone (McGregor) and Decorah
(Spechts Ferry) formation, Minnesota and Wisconsin.

PACHYGLOSSA PACHYDERMATA Cooper, new species
Plate 5, F, figures 15-18; plate 6, A, figures 1-5; plate 27, C, figure 8

Shell of medium to large size, dark brown to black in color, generally thick;
longer than wide with the length about 14 times the width; valves unequally bi-

226 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

convex, the brachial valve having the greater convexity. Lateral margins broadly
rounded ; posterior margin bluntly pointed, forming an angle of about 80°. Sur-
face marked by strong concentric undulations.

Pedicle valve unevenly convex in lateral profile with the greatest convexity
located about a third the length anterior to the beak. Anterior profile fairly
strongly convex with flat and moderately steep lateral slopes. Anterior slope
long and gentle. Umbonal region swollen. Pedicle valve with broad, shallow
pedicle groove; brachial valve with evidence of a long, low median ridge.

Brachial valve deeper than the pedicle one and with the greatest convexity
just posterior to the middle; anterior profile strongly convex with steep lateral
slopes. Anterior slope moderately steep. Outline broadly elliptical with anterior
and posterior margins subequally rounded.

Measurements in mm.—

Length Width Thickness
PIGIGEY DE - oiveievs a sa kee dee aoe ee 26.0+ 16.4 7.3+
Paratype '(1OO337) “..:- se. ce tee eens ete 19.3 15.5 3.0

Types.—Holotype: 116767; figured paratypes: 109337, 116766, 116768.

Horizon and locality—Botetourt formation in Virginia: At the junction of
Virginia Highways 311 and 114, 4 mile southwest of Catawba, Salem (15)
Quadrangle; Effna formation in Virginia: At Porterfield Quarry, 5 miles east
of Saltville; McNutt Quarry, 12 miles southwest of Bland, Burkes Garden (15')
Quadrangle; Chatham Hill formation in Virginia: At Grayson Farm, 4 miles
southwest of Bland, Bland County.

Benbolt formation in Virginia: At the Tazewell County Farm, 1 mile east of
Tazewell, Burkes Garden (15’) Quadrangle.

Pratt Ferry limestone in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton
(15’) Quadrangle.

Discussion.—This species can be readily recognized by its large size and gen-
erally thick shell. It is suggestive of P. biconvexa but is much larger, differently
colored, and thicker shelled. Specimens referred to this species from Pratt Ferry,
Porterfield Quarry, and the Benbolt at the Tazewell County Farm seem to be
younger specimens with thinner shells. Possibly the thinner shell in the latter
instances constitutes an environmental difference.

GLYPTOGLOSSA Cooper, new genus

(Greek glyptos, engraved; glossa, tongue)

Elongate oval linguloids with moderately convex valves ornamented by con-
centric lamellae scalloped along their margins. Brachial interior with median
septum reaching to about the valve middle.

Genotype.—Glyptoglossa cavellosa Cooper, new species.

Discussion.—Little is known of the interior of this genus except that the
brachial valve is provided with a median septum. The generic separation is made
on the basis of the unusual ornamentation.

In the Girvan fauna of Scotland Lingulasma ? ardmillanense Reed has the

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 227

same type of ornamentation and is thus assigned to Glyptoglossa. It also has a
median septum in the brachial valve. This species does not show the usual plat-
forms so characteristic of Lingulasma.

GLYPTOGLOSSA CAVELLOSA Cooper, new species
Plate 3, E, figures 13-20

Shell elongate-oval, length about twice the width. Sides gently rounded; an-
terior margin narrowly rounded, posterior bluntly pointed. Surface marked by
crowded concentric undulations on the sides, but where these swing over the
body of the shell they are scalloped. The overlapping of the scalloped lamellae
creates a pock-marked appearance on the outer surface.

Lateral profile moderately convex with the maximum convexity in the median
region. Anterior profiles broadly convex. Anterior third of both valves some-
what flattened.

Measurements in mm.—Holotype (minus beaks), length 19.0+, width 10.2,
thickness 4.0+.

Types.—Holotype: 109273; figured paratypes: 109272a,d; unfigured para-
types : 109272b,c.

Horizon and locality—Shippensburg formation (Pinesburg member-lower
part Echinosphaerites zone) in Maryland: On U.S. Highway 40, at Wilson, on
the west side of the bridge over Conococheague Creek, 7 miles west of Hagers-
town; same formation (lower part Nidulites zone), same as preceding; Wil-
liamsport (15’) Quadrangle. At the same horizon in the railroad cut 2 miles
southwest of Marion, Chambersburg (15’) Quadrangle.

Discussion.—This species is characterized by the peculiar scalloping of the
lamellae on the body of the shell, an ornamentation unlike that of any other
species herein described. Paratype 109272d, a partially exfoliated brachial valve,
shows an impression of a median ridge and the folded collar.

GLYPTOGLOSSA sp. 1
Plate 13, B, figure 4

Two specimens are characterized by a peculiar ornamentation consisting of
strong, concentric elevated lines with interspaces of about the same width as the
lines. The elevated lines are crowded on the posterolateral slopes but are more
distantly spaced on the median and posteromedian areas. The known specimens
indicate a small linguloid having a length of about 11 mm. and a width of about
7mm. The known valves are shallow, and the outline is the characteristic oval
of many Ordovician linguloids.

Figured specimen.—116770.

Horizon and locality—Effna formation in Virginia: McNutts Quarry, 12
miles southwest of Bland, Burkes Garden (15’) Quadrangle.

Chatham Hill formation in Virginia: On the Grayson Farm, 4 miles south-
west of Bland, Bland County.

228 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

GLOSSELLA Cooper, new genus
(Greek glossa, tongue)

Shell fairly large, thin, longer than wide and with sides gently curved but sub-
parallel ; surface marked by concentric and radial rows of small pustules. In the
posterior and median portion of the valves pustules densely crowded and matted
to give a shagreen surface. At the anterior and on the lateral areas the pustules
are arranged in more distant lines. Pedicle interior with narrow propareas be-
tween which is suspended a shallow concave plate. Muscle marks not clearly
visible in material at hand. Brachial valve with concave propareas and an in-
flected margin at the beak which is formed by the posterolateral margin of the
shell gradually turning through an angle of about 90°. Muscle scars not discerni-
ble in the material at hand.

Genotype.—Glossella papillosa Cooper, new species.

Discussion.—This genus is based on the linguloid form of the shell combined
with its hinge-region structures and the peculiar ornamentation. The ornamenta-
tion is suggestive of Lingulasma, but the interior platforms are not present in
Glossella. Furthermore, the ornamentation is not precisely like that of Lingu-
lasma. The latter genus generally has more distant radial lines, and the pustules
are often defined by gashes or pits.

GLOSSELLA LIUMBONA Cooper
Plate 4, A, figures 1-4; plate 9,I, figures 23-25; plate 13, E, figures 7-12

Shell fairly large, elongate, length about twice the width, narrowly elliptical
in outline, with gently rounded lateral margins ; posterior margin bluntly pointed ;
anterior margin narrowly rounded. Unequally biconvex in lateral profile, the
pedicle valve having the lesser convexity ; surface marked by concentric undula-
tions which are crossed by radial and concentric rows of pustules. Umbonal re-
gion of both valves marked by concentric undulations only. Surface in postero-
median portion of valve having a shagreen surface where ornamentation is very
fine.

Pedicle valve gently convex in lateral profile, with the deepest part located
near the middle ; umbonal region smooth for about 1 mm. Brachial valve broadly
convex in lateral profile, with the greatest convexity located at about the mid-
dle; anterior profile considerably more convex than that of the pedicle valve,
swollen medianly and with fairly long and steep lateral slopes.

Measurements in mm.—

Length Width Thickness
PAO PE Sean eid ke w> Lhinttens Moments ROG RONEN s 20.9-+ 12.3 5.7
Paratene (1t6786). civic scchude de alec sok 11.2 actual ? ?
4 TOR 2IBB Yas ive nleeeirolaie dhe a testa oe ial 9.5 4.6 P
. CUEGZS5 Dy) toucdescutt cusses aoe Per ee 16.3 10.1 3.4

Types.—Holotype: 116785a; figured paratypes: 109285, 116785b, 116786.
Horizon and locality—Bromide formation (Pooleville member-O-xoplecia
gouldi zone) in Oklahoma: Rock Crossing of Hickory Creek about center sec.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 229

35, T. 5 S., R. 1 E., Criner Hills, Carter County; (Pooleville member-bed 5)
Spring Creek, N} sec. 17, T. 2 S., R. 1 W., Murray County.
Discussion.—This species is represented by four specimens. Two of the speci-
mens are apparently young. The species is characterized by its nearly smooth
umbo, the densely granulated median region and the more distant well-aligned
pustules on the flanks and anterior. It differs from G. papillosa from the Pratt
Ferry Formation in its much larger size, less tapering sides and proportions.

GLOSSELLA PAPILLOSA Cooper, new species
Plate 5, G, figure 19; plate 9, J, figures 26, 27; plate 11, G, figures 12-14

Shell of about medium size for the genus, wider than long, the length about
twice the width; beak pointed, forming an angle of about 70°. Anterior margin
narrowly rounded; sides subparallel ; surface marked by extremely fine pustules
densely matted in the median region but forming closely spaced rows on the
flanks and anterior region. Umbonal region marked by concentric undulations
and growth lines only.

Pedicle valve gently convex in lateral profile and broadly convex in anterior
profile. Brachial valve considerably deeper than the pedicle one; lateral profile
gently convex but most convex in the umbonal region; anterior profile moder-
ately convex with a well-rounded median region and moderately long, steep
lateral slopes.

Measurements in mm.—Holotype, length 11.3, width 7.0.

Types—Holotype: 116787b; figured paratypes: 116787d,e, 123305; unfigured
paratypes : 116787a,c.

Horizon and locality.—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This is a much smaller species than G. liumbona from the Poole-
ville member of the Bromide formation and is much more oval in outline.

GLOSSELLA sp. 1
Plate 3, A, figure 1

This is the impression of about the posterior half of a linguloid having a prob-
able length of about 12 mm. and a width of 5 mm. The specimen is an impres-
sion of the exterior showing numerous wavy lines and a mat of fine pustules.

Figured specimen.—109319.

Horizon and locality—Botetourt formation in Virginia: Junction Virginia
Highways 114 and 311, 4 mile southwest of Catawba, Salem (15’) Quadrangle.

Superfamily TRIMERELLACEA Schuchert, 1929
Family TRIMERELLIDAE Davidson and King, 1874

Large, thick calcareous brachiopods usually subcircular to broadly oval in
outline and lenticular in profile; pedicle attachment area large, triangular and
transversely striated. Muscle scars of both valves large, and often elevated on
thickened or hollow platforms.

230 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genus OBOLELLINA Billings, 1871

Obolellina Bitt1ncs, Canadian Nat., n. ser., vol. 6, p. 221, 1871. '

Broadly oval shells suggesting Dinobolus on the exterior but with moderately
developed broad and low platform in the pedicle valve and scarcely any develop-
ment of a platform in the brachial valve. In any case the platforms are low and
consist of broad thickening only, without elevation and excavation.

OBOLELLINA CANADENSIS (Billings)
Plate 24, E, figure 24

Obolus canadensis Bitt1ncs, Canadian Nat. Geol., vol. 3, p. 441, figs. 20-23 (not fig. 19 =
O. magnifica), 1848; Geol. Surv. Canada, Rep. Progress for 1857, p. 180, figs. 20-23 (not
fig. 19), 1858; Geol. Canada, p. 142, fig. 75, 1863.

Obolellina canadensis (Billings), Canadian Nat. Geol., n. ser., vol. 6, p. 222, 1871; ibid.,
p. 326, fig. 15, p. 320, fig. 6, 1872.

Dinobolus canadensis (Billings) DAvipson and Kine, Quart. Journ. Geol. Soc. London,
vol. 30, p. 162, pl. 19, fig. 7, 1874—Witson, Geol. Surv. Canada, Bull. 8, p. 16, pl. 1,
fig. 24, 1946.

Types.—Holotype: G.S.C. 1150; paratype: G.S.C. 1150a.
Horizon and locality.—Leray-Rockland beds, Fourth Chute of the Bonnechére
River, Renfrew County, Ontario, Canada.

OBOLELLINA DIXONENSIS Cooper, new species
Plate 22, K, figures 18-21

Exterior of shell not known; length of beak not known; shell evidently thin.
Valves subequally convex. Impressions of the pedicle interior indicate a trans-
versely oval outline ; lateral margins narrowly rounded; anterior margin broadly
rounded. Lateral and anterior profiles broadly convex and nearly equal; lateral
slopes short and moderately steep; median region depressed convex in anterior
profile.

Pedicle interior with a moderately thickened, nonexcavated, diamond-shaped
muscle area; sides of muscle area narrowly angulated in the middle; anterior
narrowly rounded. Individual scars not clear, but a depressed track extending
from the apex to the anterior angle suggests the growth path of 2 unidentified
muscles. Brachial muscle platform similar in outline to the pedicle one; indi-
vidual muscle marks not identifiable. The holotype (71814a) measures 15.2 mm.
long by 20.3 mm. wide, representing measurement of interior surface only.

Types.—Holotype: 71814a; figured paratype: 71814b; unfigured paratypes:
7181 4c-1.

Horizon and locality.—Platteville formation (just above sponge bed), Tru-
man’s Quarry, 2 miles northeast of Dixon, III.

Discussion—This species is suggestive of O. parva (Whitfield) from the
Prosser limestone of Minnesota and Wisconsin but differs in being a larger and
more tranverse shell and in lacking any trace of median septa anterior to the
muscle platforms.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 231

Although only internal impressions are available for study, the species is as-
signed to Obolellina because of the modest thickening and nonexcavated char-
acter of the muscle platforms. The species evidently is an early form of dinobolid
in which the muscle platforms are in an incipient stage of development.

OBOLELLINA ERECTA (Wilson)
Dinobolus erectus Witson, Geol. Surv. Canada, Bull. 8, p. 17, pl. 1, fig. 25, 19046.

Type.—Holotype: G.S.C. 6301.
Horizon and locality—Leray-Rockland beds, Fourth Chute of the Bonnechére
River, Renfrew County, Ontario, Canada.

OBOLELLINA MAGNIFICA (Billings)
Plate 13, A, figures 1-3; plate 24, F, figure 25

Obolus canadensis Bittincs (part), Geol. Surv. Canada, Rep. Progress for 1857, p. 180,
fig. 19 (not figs. 20-23), 1858; Canadian Nat. Geol., vol. 3, p. 441, fig. 19 (not figs. 20-23),
1858.

Obolellina magnificus (Billings), ibid., n. ser., vol. 6, p. 329, fig. 7, 1872.

Dinobolus magnificus (Billings) Davipson and Kine, Quart. Journ. Geol. Soc. London,
vol. 30, p. 164, pl. 19, fig. 8, 1874—NicHotson, Paleont. Province Ontario, p. 17, fig. 6,
1875.—Witson, Geol. Surv. Canada, Bull. 8, p. 17, pl. 1, figs. 26, 27, 1046.

Broadly oval in outline, beak somewhat pointed, forming an angle of about
110° ; prominence of beak emphasized by a slight depression in the posterolateral
margins. Lateral and anterior margins strongly rounded and approximately a
circle. Valves unequally biconvex, the brachial valve having the greater con-
vexity. Surface marked by concentric lines of growth and strong growth varices.

Pedicle valve gently convex in lateral profile and with the greatest convexity
in the posterior third; anterior two-thirds somewhat flattened. Anterior profile
broadly convex with long and gentle lateral slopes.

Brachial valve moderately and evenly convex in lateral profile; greatest con-
vexity at about the middle; anterior profile with broadly swollen median area
and short, moderately steep lateral slopes. Beak small, set off by short slopes ;
beak protruding slightly posterior to the posterior margin.

Pedicle interior with broad and shallow pedicle groove; posterior thickened
by a broad muscle callosity extending to about the middle of the valve; muscle
marks not preserved in the specimens at hand.

Brachial interior with unthickened posterior margin; posterior region thick-
ened to form a muscle platform, perforated by a deep pit at the umbo.

Measurements in mm.—

Length Width Thickness
Hypotype (pedicle valve 116800a) .......... 29.2 29.0 4.5
fs (brachial valve 116800b) ........ 23.5 28.0 4.8

Types.—Holotype: G.S.C. 1161; paratypes: G.S.C. 1161a-d; figured hypo-
types: 116800a,b,d; unfigured hypotype: 116800c.

Horizon and locality —Rockland formation in Ontario, Canada: At Paquette
Rapids ; Bonnechére River, 1 mile below Eganville.

232 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion.—The specimens available for study are not very well preserved.
The U. S. National Museum specimens are thin shelled and probably young
forms. This may account for the small development of the muscle platforms.
This species is proportionally wider than long and thus contrasts strongly with
O. canadensis which is the reverse.

OBOLELLINA PARVA (Whitfield)

Dinobolus ? parvus WHITFIELD, Geol. Wisconsin, vol. 4, pl. 27, figs. 8-10, 1882—WINCHELL
and SCHUCHERT, Geol. Minnesota, vol. 3, p. 356, fig. 27, 1803.

This interesting species differs strongly from O. dixonensis particularly in
details of the brachial valve. Obolellina parva has a fairly strongly developed
and prominent median ridge extending anterior to the muscle platform. A trace
of a median ridge is also present in the opposite valve. An impression of the
brachial interior (45548a) shows a depression bounded by 2 short, low ridges,
but the significance of this structure is not at once evident. It may be a depres-
sion similar to that in the brachial umbo of O. magnifica.

Types.—Holotype in the form of wax impressions of the two valves: 45548a,b.

Horizon and locality.—Prosser formation (Fusispira bed), Wykoff, Minn.

Family LINGULASMATIDAE Winchell and Schuchert, 1803

Linguoidal, corneous brachiopods with large internal platforms.

Genus LINGULASMA Ulrich, 1899
Lingulasma Utricu, Amer. Geol., vol. 3, p. 383, 1880.

Most of the species of this genus found in lower Middle Ordovician rocks are
generally imperfect. Many of the occurrences are found in vertical position in
the rock, with the beak and platform regions badly crushed. As a consequence
the apical region of both valves and the nature of the platforms of most species is
still unknown. The character of the ornamentation with its rows of pustules or
elevated dashes is generally very distinctive, and the variety of ornament makes
specific splits possible on only small sections of the shell.

LINGULASMA COMPACTUM Cooper, new species

Plate 12, F, figures 18-21

Shell longer than wide, with subparallel sides and somewhat narrowly rounded
anterior margin. Valves subequal in depth. Traces of platforms visible in
crushed posterior third. Ornamentation distinctive, consisting of strong con-
centric undulations of growth; surface of sides and flanks covered by crowded,
rounded, minute, wavy concentric lines but on body of shell in the median re-
gion the concentric elements become minutely discontinuous, the concentric
ridges bearing granules arranged in radial rows. Radial elements only poorly
developed on the flanks and along the margins, but on the median region the
rows are closely crowded, about 7 in the space of a millimeter.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 233

Measurements in mm.—Holotype, length 22.0, width 17.0, thickness 6.0 in-
cluding both valves.

Type.—Holotype: 109347.

Horizon and locality—Oranda formation in Virginia: 0.6 mile northwest of
Linville Station, Broadway (15’) Quadrangle.

Discussion.—The specimen on which this species is based is somewhat better
preserved than is usual for the genus. Unfortunately, the usual crushing of the
beaks has taken place, but the outer shell showing the ornamentation is beauti-
fully preserved. The species was somewhat more slender than any of those yet
described in this country. The surface is most like that of L. ? matutinum in
the strength of the concentric elements but differs in the more closely crowded
radial rows of granules.

LINGULASMA MATUTINUM Cooper, new species
Plate 12, D, figures 9-11

Species based on fragments of three specimens. Sides subparallel and anterior
margin broadly rounded. Valves subequal in depth and profiles. Interiors not
preserved. Ornamentation consisting of fine, even, closely spaced, minutely wavy
radial lines. Wavy lines with small granules arranged radially. Concentric lines
closely crowded along the margins and with granules either not present or not
preserved. Posteriorly radial and concentric elements becoming more or less
merged to produce the appearance of a minutely beaded surface.

f

Measurements in mm.—

Length Width Thickness
PAPMSEY PE cates Se ers tra «Vis atc owas ake «tole Mahe 19.6-+ 23.0 11.4
Baratype /(LOOZA8C) eet osteo ores 25.I-+ 22.4 12.2

Types.—Holotype: 109348a; figured paratype: 109348c; unfigured paratype:
109348b.

Horizon and locality—Upper 25 feet of the Arline formation in Tennessee:
In glade 4 mile southeast of Friendsville, Concord (T.V.A. 138-SW) Quad-
rangle.

Discussion.—This species suggests L. compactum but differs in its much larger
size and coarser ornamentation.

LINGULASMA OKLAHOMENSE Cooper, new species
Plate 12, E, figures 12-17

Large, very thin shelled; outline subquadrate; longer than wide; lateral mar-
gins nearly parallel; anterior margin nearly straight ; posterior margin narrowly
rounded. Anterolateral extremities somewhat narrowly rounded. Valves un-
equally convex, the brachial valve having the greater depth. Anterior third of
each valve flattened.

Ornamentation consisting of radiating lines of low elevations most distinct on
the median portions and front of the valves but disappearings on the flanks, which
are marked only by crowded undulations. Elevations consisting of narrow thread-

234 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

like ridges with their long axis arranged radially. Ridge with a long gentle slope

on one side and a steep, precipitous face on the other, or a carina may occupy

the middle of the elevation. Anterior side of the carina with a pit or gash, sepa-

rating the elevation from the next anterior one. Asymmetrical elevations located

mainly on sides of shell and with the long slope facing the lateral margin.
Brachial interior: Platform low; septum low and short.

Measurements in mm.—

Length Width Thickness

EIGHIOLU DS” Gees ce ore eee ce coe ons meee 21.7+ 19.0 8.4?

Pafatype (zoogs2e)'t 20. OG AL Baer 27.5-+ 23.2 13.4?
ff (ro9g40a)} ci. atith. 2e.P eirien: 28.6 25.2 11.8

Types.—Holotype: 109353b; figured paratypes: 109352d,e, 109353a; un-
figured paratypes: 109349a, 109352a-c,f,g.

Horizon and locality—Bromide formation (Pooleville member-Oxoplecia
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek about center
Bet s5. Pe GS) Re ee riner Fis, Warter’ County.

Discussion ——This species differs from the two previously described species of
this genus by its ornamentation and large size. The radial elevations of L. gale-
nense are smaller and more distantly spaced than those of L. oklahomense.
From L. schucherti the Oklahoma species is distinguished by the crowded
concentric lines and absence of radial marking on the flanks. In L. schucherti
the flanks are marked by crowded growth lines, and the radial elevations are
more closely spaced. Furthermore, in L. schucherti the radial elevations are of
different character from those of L. oklahomense, being more elongate at right
angles to the radial direction and without the carina.

LINGULASMA OCCIDENTALE Cooper, new species
Plate 13, F, figures 13-17

Shell thin, of about medium size for the genus; apical angle about 90° ; sides
nearly parallel and straight ; anterolateral extremities narrowly rounded ; anterior
margin very gently curved or nearly straight ; pedicle valve with nearly flat lateral
profile; brachial valve with gently convex lateral profile; surface marked by
fine, concentric, minutely wavy lines and radial lines of minute granules.

Measurements in mm.—Holotype, length 18.4, width 16.2, thickness 6.2.

Types.—Holotype: 116793b; figured paratypes: 116793a, 117955; unfigured
paratype: 117956.

Horizon and locality —Yellow limestone above 25-foot sandstone of Eureka
group in Nevada: 3 miles north of Martin Ranch on southwest side of hill 8167,
Monitor Range, Roberts Mountains (1°) Quadrangle.

Discussion.—This species is suggestive of L. matutinum and L. compactum
in the closely crowded concentric ornamentation but differs from both of the
others in the greater degree of crowding and compaction of the ornamentation.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 235

LINGULASMA sp. 1

Two specimens from the Oranda formation indicate a species not yet described.
The ornamentation is quite unlike that of L. compactum but is more suggestive
of L. oklahomense. These specimens have strong concentric lamellae on the pos-
terolateral areas which are covered by fine, crowded, concentric lines and rows
of granules. In the median and anterior portions of the shell the rows of granules
are distant, about 4 to the millimeter.

Described specimens.—109354, 123303.

Horizon and locality—Oranda formation in Virginia: Along the Southern
RR. tracks 4 mile west of Strasburg, Strasburg (15’) Quadrangle, and 0.4
mile west of U. S. Highway 11 on Virginia Highway 55, in the north edge of
Strasburg, Strasburg (15’) Quadrangle.

LINGULASMA sp. 2

This species, which is represented by the front end only, is the largest that has
been found. The specimen measures 34.6 mm. in width. It is marked medially
by distant rows of pustules, about 5 to the millimeter, but laterally it is marked
by strongly crowded concentric lines and more closely spaced rows of pustules.
The specimen was found in the lower portion of the Pinesburg member of the
Shippensburg formation on U. S. Highway 40 at Wilson, 7 miles west of Hagers-
town, Williamsport (15’) Quadrangle, Md.

Described specimen.—123304.

LINGULASMA sp. 3

Shell small for the genus, perhaps a young specimen, somewhat rectangular
in outline; sides subparallel; anterior margin nearly straight; anterolateral ex-
tremities narrowly rounded. Surface marked by distant concentric undulations
over which are superimposed fine, crowded wavy lines and closely spaced rows
of pustules.

Measurements in mm.—116794, length 15.8+, width 12.4, thickness 4.2+.

Described specimen.—116794.

Horizon and locality—Edinburg formation (lower part of the middle of the
Nidulites zone) in Virginia: Beside the road along Tumbling Run, 14 miles
southwest of Strasburg, Strasburg (15’) Quadrangle.

Discussion.—The ornamentation is very much like that of L. compactum in
its crowded nature but differs in having more distant concentric undulations and
a lesser development of the pustules.

Genus LINGULOPS Hall, 1871
LINGULOPS CLIFTONENSIS Foerste
Plate 23, C, figures 5, 6
Lingulops cliftonensis ForrstE, Journ. Geol., vol. 11, p. 38, 1903.
Figures of this species are introduced to show the extent of development of

the platform in the brachial valve of Lingulops. Compare with Elliptoglossa and
Lingulops norwoodi on the same plate.

236 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Holotype.—78667.
Horizon and locality—Fernvale formation, Clifton, Tenn.

LINGULOPS NORWOODI (James)
Plate 23, A, figures 1-3; plate 23, B, figure 4
For complete synonymy see Bassler, U. S. Nat. Mus. Bull. 92, p. 741, 1915.

Figures of this species are introduced to show a form with more modest de-
velopment of the platform in the brachial valve. The figures also show speci-
mens of the same species with varying development of this species. Compare
all with Elliptoglossa.

Figured specimens.—15863a, 45219a,b.

Horizon and locality Upper part Trenton formation, Ludlow and West Cov-
ington, Ky.

Family PATERULIDAE Cooper, new family

Subcircular to elliptical, corneous shells, lenticular in profile; sides with flat-
tened rim; pedicle valve with pedicle notch or shallow pedicle groove.

This family consists mainly of small, scalelike shells which although common
enough from the Ordovician through the Devonian, are very poorly understood.
In some places these shells occur in countless numbers. They are so unlike
brachiopods in some respects that one of the genera was suggested to be a
gastropod (Sardeson, 1931, p. 353). However, specimens of Craniops are
known, and one is illustrated herein, with both valves in contact showing that
the genus is really a bivalved form and by its symmetry and musculature is
undoubtedly a brachiopod. The genus Paterula commonly occurs in black shales
or in limestones associated with black shale. Elliptoglossa is less well known,
but it too occurs in black shale or in bituminous limestones. Craniops, on the
other hand, is a common associate of normal shelly faunas.

Genus PATERULA Barrande, 1879

Paterula BARRANDE, Syst. Sil. Centre Boheme, vol. 5, p. 110, 1870.
Paterula Barrande, Davipson, General summary to British fossil Brachiopoda, p. 391, 1884.
Paterula Barrande, HALL and CLarkE, Pal. New York, vol. 8, pt. 1, p. 78, 1893.

Shell minute, polished brown, cream yellow or black, inequivalved, the brachial
valve having the greater depth; subcircular to oval in outline. Pedicle valve flat
to gently convex in profile; brachial valve moderately to strongly convex. Sur-
face ornamented by concentric lines and undulations of growth.

Inside of both valves provided with a more or less wide, flattened border like
that of Elliptoglossa and an inner narrowly elevated border surrounding the vis-
ceral cavity. Pedicle valve with a posterior pedicle groove and notch; brachial
valve with margin unnotched. Inside the pedicle valve 2 slightly divergent im-
pressed lines extend from a point just anterior to the pedicle notch anteriorly to
about the middle of the valve. These lines terminate on each side of a large, round
muscle scar. Anterior to the circular scar numerous pallial impressions radiate
anteriorly, anterolaterally and laterally. Small scars occur on the anterolateral

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 237

sides of the central scar and also a short distance posterolaterally of the central
scar. Two pits appear on each side of the median line and just anterior to the
pedicle notch, and anterolateral to these and close to the margin occur another
pair of muscles.

The brachial valve is characterized by a strong and deep umbonal muscle pit.
From this pit 2 pallial trunks extend anterolaterally for about one-third the
length of the valve. Two small muscle scars are located near the center, but other
scars are obscure.

Genotype—FPaterula bohemica Barrande, Syst. Sil. Centre Bohéme, vol. 5,
p. 110, pls. 95, 152, 1879.

Discussion.—Little has been known of this peculiar genus because its shells
are generally very rare. Until the present writing a single species, P. amit, was
known in North America. Excellently preserved specimens occur in many parts
of the Southern Appalachians from Alabama to Pennsylvania which afford new
information on the genus. Unfortunately, the specimens are so small and the
muscle marks so faintly impressed that description of the interior is difficult.

One of the most striking features of the pedicle interior is the occurrence of
a fine impressed line originating just anterior to the pedicle notch. This line
divides, and the 2 branches extend anteriorly to about the middle of the valve.
Anterior to the end of these lines occurs a network of minute pallial impressions
that radiate anteriorly, anterolaterally, and laterally.

The muscle system of the pedicle valve is difficult to establish, but it seems
certain that the following are present: 2 small umbonal muscles, a large central
one, 2 pairs of small muscles occurring anterolateral and posterolateral to the
central one, and a pair or 2 pairs anterolateral to the pedicle notch and located
just under the margin.

The interior of the brachial valve is less clearly defined in the specimens avail-
able. The big umbonal muscle patch with the 2 short but prominent pallial trunks
diverging from it are the most striking features.

In the rocks under consideration Paterula occurs rarely in the Arline forma-
tion but it is common in the Botetourt and Oranda formations. It occurs in the
Liberty Hall facies, and two specimens are known from the Trenton of New
York. The genus has been taken in the Bromide and Viola formations of Okla-
homa. It is thus evident that it may be expected in any rocks from Black River
to high Trenton. The genus is most abundant in bituminous limestones or lime-
stones associated with black shales such as those of the Botetourt, Oranda, and
Liberty Hall facies between Harrisonburg and Winchester, Va. Specimens are
very abundant in the Pratt Ferry formation at Pratt Ferry, Blocton Quadrangle.
These limestones yield large numbers of specimens when the blocks are dissolved
in acetic acid. The Botetourt limestone in the vicinity of Strasburg, Va., yields
free specimens on etching with hydrochloric acid. The same treatment will yield
small numbers of specimens from various parts of the Nidulites zone of the
Edinburg formation.

The genus also occurs in abundance in limestones of the Table Head forma-

238 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

tion, Newfoundland, and the Quebec City formation in Quebec, Canada. The
earliest species is from the Shumardia zone of Quebec.

PATERULA AMII Schuchert

Paterula sp. Hart and CLarkE, Pal. New York, vol. 8, p. 78, pl. 4, K, fig. 1, 1893.
P. amti Scuucuenrt, U. S. Geol. Surv. Bull. 87, p. 301, 1897—REUDEMANN, New York State
Mus. Bull. 42, p. 560, pl. 1, fig. 2, 190T.

Horizon and locality—Quebec City formation: South of St. Johns Market,
Quebec, Province of Quebec, Canada. Normanskill formation: Mount Merino,
near Hudson, N. Y. Humber Arm series, Newfoundland.

PATERULA PERFECTA Cooper, new species
Plate 18, H, figures 54-56; plate 24, D, figures 12-23

Shell small, inequivalved, subelliptical in outline. Anterior and posterior mar-
gins slightly more narrowly rounded than the lateral margins. Surface of both
valves ornamented by fine concentric undulations and very obscure and fine
radial lines.

Pedicle valve gently convex in profile with the greatest convexity at the pos-
terior third; beak submarginal, smooth, pedicle notch small.

Brachial valve strongly convex in profile with the greatest convexity a little
posterior to the middle. Beak obscure, smooth, located a little less than one-fifth
the length of the valve from the posterior margin. Posterior slope steep and
gently concave ; anterior slope gentle and convex. Lateral slopes moderately steep
but flat.

Measurements in mm.—

Length Width Thickness
Paratype (pedicle valve 116799a)............. 3.1 3.0 0.5
% f Tk, MODADE )), cals ia iatilGanstets 2.0 1.8 ?
- (brachial valve 109409d) ........... 2.5 2.1 0.6

Types.—Holotype: 109409k ; figured paratypes : 109404c-e,g, 109407, 109409¢,
h,i,o-g, 116799a-c, 109408a; unfigured paratypes: 109404a,b,f, 109406a-e,
109408b, 109409a,b,d-g,j-n.

Horizon and locality —Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Limestone in the base of the Whitesburg formation in Tennessee: 14 miles
west of Bulls Gap, and 2 to 24 miles southeast of Whitesburg, Bulls Gap (T.V.A.
171-SE) Quadrangle. Arline formation in Tennessee: 4 mile southeast of
Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Botetourt formation in Virginia: Porterfield Quarry, 5 miles east of Saltville,
Maccrady (T.V.A. 218-NW) Quadrangle; 4 miles southwest of Bland, Bland
County ; 14 miles southeast of Harrisonburg, Harrisonburg (15’) Quadrangle;
1 mile northeast of Harrisonburg; 4 mile west of Strasburg, Strasburg (15’)
Quadrangle.

Botetourt formation (Cybeloides bed) in Virginia: Opposite the dam on the
Shenandoah River, 1 mile north of Edinburg, Edinburg (15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 239

Edinburg formation (Liberty Hall facies) in Virginia: 14 miles south of
Wadesville, Winchester (15’) Quadrangle; opposite the bridge at Riverton,
Front Royal (15’) Quadrangle.

Oranda formation in Virginia: 4 miles northwest of Linville Station, Broad-
way (15’) Quadrangle.

Discussion.—This species is common in the Liberty Hall facies of the Edin-
burg formation and in limestones associated with the black shale in Alabama,
especially at the base. The most nearly comparable species is the small P. polita
from the Viola formation of Oklahoma. The latter is smaller and somewhat more
oval and with less convexity to both valves.

PATERULA POLITA Cooper, new species
Plate 24, A, figures 1, 2

The known specimens of this species are somewhat smaller than those of
P. perfecta, but there are a number of more important differences between the
two species. The pedicle valve of P. polita is more narrowly rounded at the pos-
terior and with a much smaller pedicle opening than in P. perfecta. The brachial
valve of P. polita is much less convex than the same valve of P. perfecta.

Measurements in mm.—

Length Width Thickness

Holotype (pedicle valve) .............-...06- 1.9 1.6 ?
Paratype. (brachial valve) vi... 6... 6c capes Be 1.5 0.3

Types.—Holotype: 109411b; paratype: 10941 Ia.

Horizon and locality.—Viola formation (lower), in Oklahoma: SE4 sec. 32,
T.2S., R. 2 E., 3 miles north-northeast of Springer, Murray County.

Discussion.—For differences from P. perfecta see p. 238.

PATERULA SUBCIRCULARIS Cooper, new species

Plate 24, C, figures 7-10

Shell fairly large for the genus, nearly circular in outline, the anterior margin
somewhat more narrowly rounded than the posterior margins and producing
a slightly oval outline. Surface marked by concentric undulations. The pedicle
valve is gently convex in profile with the maximum convexity at about the middle
where the valve is slightly swollen. Pedicle notch narrow and deep. Lateral
border narrow on all margins, but widest on the posterolateral extremities.

Brachial valve much like the pedicle valve and having nearly the same con-
vexity. All borders narrow but the posterior one wider than the others.

Measurements in mm.—Brachial valve (paratype 109414c), length 4.1, width
3.6.

Types.—Holotype: 109414b; paratypes: 10941 4a,c.

Horizon and locality.—Stringtown shale= Womble shale (Big Fork chert) in
Oklahoma: Near the center of sec. 29, T. 1 S., R. 12 E., on south bank of north
Boggy Creek, near base of exposure, southwest of Stringtown, Atoka County ;

240 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

sec. 28, T. 3 N., R. 20 E., Latimer County ; Round Prairie, Potato Hills, Latimer
County.

Discussion.—This species can be recognized by its large size relative to the
others described and by its nearly circular form. The three specimens on which
the species is based vary in size but indicate a species in which the two valves
were nearly equal in convexity. In its form and subequal convexity, this species
differs from the others herein described.

Genus CRANIOPS Hall, 1859
CRANIOPS ATTENUATA Cooper, new species
Plate 22, A, figure 1
Craniops HALL, 12th Rep. New York State Cab. Nat. Hist., p. 84, 1859.

Shell large for the genus, oval in outline, widest slightly posterior to the mid-
dle but narrowing anteriorly ; posterior margin more broadly rounded than the
anterior one; apex located about one-fifth the length from the posterior margin ;
anterior slope gently convex, long and sloping gently to the anterior margin;
posterior slope short, steep, and gently concave. Surface smooth except for
growth plaits which are distant and number 8 or 9. These are distant in the
median region but crowded in the posterolateral areas.

Measurements in mm.—Holotype, length 4.9, width 3.8, height 1.1.

Type.—Holotype: 116708.

Horizon and locality—aIn Alabama (near the top of the massive limestone)
Carters formation: Quarry 0.3 miles north of Gate City, Leeds (15’) Quad-
rangle.

Discussion—This is a large species having a length slightly in excess of
C. trentonensis (Hall) to which it may be compared. It differs from that species
in having an attenuated anterior margin and in the apex being located farther
forward of the posterior margin.

CRANIOPS MINOR (Winchell and Schuchert)

Pholidops trentonensis minor WINCHELL and SCHUCHERT, Geol. Minnesota, vol. 3, p. 376,
pl. 20, fig. 40, 1893.

Horizon and locality——Decorah formation (Guttenberg member-Ctenodonta
bed, Ion member-Phylloporina bed), and Prosser formation (Clitambonites and
Nematopora beds) in Minnesota.

CRANIOPS TENUIS Cooper, new species
Plate 22, C, figures 3-5

Shells thin, small, often both valves in contact ; longitudinally elliptical to sub-
oval in outline with the posterior slightly wider than the anterior. Lateral and
posterior margins broadly rounded but anterior margin slightly more narrowly
rounded than the posterior one. Valves subequally convex, the pedicle valve
slightly less convex than the brachial and with the beak situated slightly anterior
to that of the brachial valve. Brachial lateral profile with a bulge produced by

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 241

a median swelling. Pedicle posterior slope more gentle than the brachial one.
Beaks directed posteriorly, umbones small, narrowly rounded, and slightly ele-
vated. Both valves marked by fine concentric lines and a few distant concentric
growth lamellae.

Measurements in mm.—Holotype, length 2.2, width 2.0, thickness 0.7.

Types.—Holotype: 109752a; unfigured paratypes: 109752b-l.

Horizon and locality—Bromide formation (Pooleville member-O-xoplecia
gouldi zone), in Oklahoma: At Rock Crossing of Hickory Creek, about center
sec. 35, [.5 S., R. 1 E.; ona branch of Hickory Creek in NW4 sec. 26, T. 5 S.,
R. 1 E., Criner Hills, Carter County. Two specimens are placed here that come
from the Bromide formation (Mountain Lake member) at the Rock Crossing of
Hickory Creek, and midway between Davis and Dougherty, NW34 sec. 27, T. 1
S., R. 1 E., Murray County.

Discussion.—This species by its small size suggests C. minor (Winchell and
Schuchert) but differs in its still smaller size, less oval outline, and much fewer
growth plaits. It is a far smaller shell than C. trentonensis Hall and will not be
confused with it.

CRANIOPS TRENTONENSIS (Hall)
Plate 22, B, figure 2

Pholidops trentonensis Hatt, Descr. new species Crinoidea and other fossils, p. 14, 1866;
24th Ann. Rep. New York State Cab. Nat. Hist., p. 221, pl. 7, fig. 8, 1872.—BAssLER,
U.S. Nat. Mus. Bull. 92, p. 960, 1915.

Nealmont formation in Pennsylvania: Reedsville, Lewistown (15’) Quad-
rangle. The collection from which the specimens were taken includes such genera
as Pionodema which indicates clearly that these “Stones River” beds must be-
long to the Nealmont formation and therefore must be of Trenton age. The
nearly circular form of the shell, its large size, and the distant plaits are features
that it shares with C. trentonensis. It is of about the same size as C. attenuata,
but that species is narrowed anteriorly.

Figured specimen.—10g9788b.

ELLIPTOGLOSSA Cooper, new genus
(Greek ellipto, elliptical; glossa, tongue)

Shell small, longitudinally elliptical in outline with anterior and posterior mar-
gins subequal, depth of valves subequal; surface marked by fine concentric lines
and concentric undulations. Radial markings present in some species.

Pedicle interior: Outer margin smooth and flattened along the line of valve
junction; posterior margin broadly flattened and marked medially by a narrow
depression, probably a pedicle groove. Pedicle attached to a small roughened
area at the extreme posterior. Musculature suggesting Lingula but not identical
with it. The umbonal muscle (or muscles) the most strongly impressed, but
the external, central, and middle muscle scars discernible. The large laterals of
Lingula apparently are absent. The visceral region forms a crudely trapezoidal
area with the lateral angles formed by oblique, hooklike impressions. A low
ridge extends from the umbonal muscle to a point anterior to the center.

242 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial interior: Umbonal and external muscles along the median line usu-
ally clearly visible but additional musculature not yet identified. Margins
flattened.

Genotype.—Leptobolus ? ovalis Bassler = Elliptoglossa ovalis (Bassler), Cam-
brian and Ordovician: Geol. Surv. Maryland, p. 230, pl. 49, figs. 14-16, 1919.

Discussion.—The members of this interesting little genus can be identified by
their longitudinally elliptical or narrowly oval outline, the broad and flat outer
rim, and the absence of a clearly defined pedicle groove.

Elliptoglossa most closely resembles the peculiar genus Lingulops which is
regarded by some brachiopod students as one of the earlier members of the Tri-
merellidae. Like Lingulops the genus under consideration has the same exter-
nal form and the same type of flattened contact surface bounding the visceral
region. Another striking analogy is in the faint groove marking the median por-
tion of the posterior border, which is regarded as a pedicle groove. The interior
of Lingulops is, however, unlike that of Elliptoglossa. The muscles of the latter
are not so clearly impressed, and no tendency to the development of a platform
at the anterior end of the muscle field has been detected. Inasmuch as the ex-
ternal form and ornamentation of Elliptoglossa and Lingulops are alike and their
musculature is similar, it is possible that the latter was derived from the former.

In its possession of a flattened brim surrounding the valves, Elliptoglossa is
suggestive of Paterula, but the two should not be confused because the pedicle
valve of the latter genus has a distinct notch and the valves are usually unequal
in depth. The brachial valve of Paterula is usually deeper and more convex than
that of the pedicle valve. Another feature distinguishing the two genera is that
of external shape: Elliptoglossa in all its known species is elongate whereas the
valves of Paterula are generally subcircular to suboval, the little tapering present
taking place in an anterior direction.

Elliptoglossa appears first in the Shumardia zone of the Lévis formation high
in the Canadian where it is represented by Paterula westom Clarke. This is a
large species, but it has all the characters of the new genus. A similar species
occurs in the Quebec City formation at Quebec. It also occurs in abundance in
the Pratt Ferry formation at Pratt Ferry, Ala., where it can be etched from the
limestone by acetic acid. The genotype species occurs in the Sinuwites beds at the
base of the Martinsburg shale in Pennsylvania. Elliptoglossa is again en-
countered in the Botetourt formation of Virginia and Tennessee and ranges into
the Oranda formation where it is common. One fine species occurs in the high
Ordovician (Maquoketa) of Missouri and the Sylvan shale of Oklahoma.

ELLIPTOGLOSSA OVALIS (Bassler)
Plate 23, E, figures 14-26
Leptobolus ? ovalis Basster, Cambrian and Ordovician: Geol. Surv. Maryland, p. 230,
pl. 49, figs. 14-16, 1910.

Shell small, longitudinally oval in outline with the posterior margin slightly
narrower than the anterior margin. Anterior and posterior margins narrowly

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 243

rounded. Maximum width at the middle. Sides moderately curved. Valves
marked by even, concentric lines.

Pedicle valve evenly and broadly convex in lateral profile with the maximum
convexity located at the middle ; anterior profile narrowly convex. Valve swollen
medianly, with steep lateral slopes but a more gentle anterior slope. Apical angle
go® to 100°. Posterior slope long and gentle. Umbo small, short, narrowly
swollen.

Brachial valve somewhat more rounded than the pedicle valve and less con-
vex in anterior and lateral profiles. Inner border of both valves fairly wide, but
widest at the posterior.

Measurements in mm.—

Length Width
CURIE BS retest at Sci, bh, ate dou 9 as acasnsetcueap eoatiaud eu Mauer Ieee 57 3.7
Paratype) Gi003576) wc enced. 228 ALU. ABBE! 4.0 2.5

Types.—Lectotype: 661714; figured paratypes: 66171c (b,e, Bassler, 1919) ;
unfigured paratype : 661714 ; figured hypotypes: 109357b-e,f, 109370a, 109371a,b,
109378a, 109379a, 109380.

Horizon and locality—Martinsburg formation (base of Sinuites bed) in Penn-
sylvania: 2 miles northwest of Kauffman, Chambersburg (15’) Quadrangle;
along the railroad south of highway crossing, 24 miles southwest of Marion,
Chambersburg (15’) Quadrangle.

Oranda formation in Pennsylvania: 1 mile south of St. Thomas, Mercersburg
(15’) Quadrangle ; 2 miles southeast of Mercersburg, Mercersburg (15’) Quad-
rangle; just north of Chambersburg and 5 miles south-southwest of Chambers-
burg, Chambersburg (15’) Quadrangle.

Botetourt formation in Virginia: 4 miles southwest of Bland: Hoge Farm, 6
miles southwest of Bland; near Lusters Gate, 3 miles (airline) east of Blacks-
burg, Blacksburg (15’) Quadrangle; 2 miles northeast of Blacksburg, Blacks-
burg (15’) Quadrangle; 1 to 2 miles west of Lexington, Lexington (15’) Quad-
rangle; 14 miles southeast of Harrisonburg, Harrisonburg (15’) Quadrangle;
on the boundary of the George Washington Forest, 1.8 miles south-southwest
of Bethel Church, 6 miles (map measure) due east of Harrisonburg, Harrison-
burg (15’) Quadrangle.

Botetourt formation in Tennessee: 2 miles south of Albany, Mosheim (T.V.A.
181-NW) Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: 2 miles southwest of
Broadway, Broadway (15’) Quadrangle; just northwest of Lee Highway at
Lacey Springs, Broadway (15’) Quadrangle; 300 feet north of U. S. Highway
60, 1 mile north of the railroad station at Lexington, Lexington (15’) Quad-
rangle; 14 miles northeast of Harrisonburg on Lee Highway (U. S. 11), Har-
risonburg (15’) Quadrangle; 14 miles east of Tenth Legion, Mount Jackson
(15’) Quadrangle; 1 mile due west of Hollins, Roanoke (15’) Quadrangle; 14
miles south of Wadesville, Winchester (15’) Quadrangle.

244 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Effna formation in Virginia: Porterfield Quarry, 5 miles east of Saltville,
Maccrady (T.V.A. 218-NW) Quadrangle.

Oranda formation in Virginia: 4 miles northwest of Linville Station, Broad-
way (15’) Quadrangle.

Whitesburg formation in Tennessee: 24 miles southeast of Whitesburg, Bulls
Gap (T.V.A. 171-SE) Quadrangle.

Discussion.—This species is characterized by its elongate oval form with nar-
rowly rounded extremities and fairly wide inner borders. The specimens are
usually lustrous black in color but may weather to a reddish hue as southwest
of Bland, Va. Interior details are very difficult to determine.

Elliptoglossa ovalis differs from E. sylvanica in its sharper beaks, more elon-
gated form, and narrower extremities.

ELLIPTOGLOSSA ROTUNDATA Cooper, new species
Plate 24, B, figures 3-6

This species may be distinguished from EF. ovalis by its proportionately rounder
anterior and posterior margins, more rounded sides, and stronger concentric
undulations. The same features distinguish it from E. sylvanica although with
the latter species the differences are not so striking.

Measurements in mm.—Holotype, length 5.0, width 3.6.

Types.—Holotype: 71885a; figured paratypes: 109386a, 71885c,d; unfigured
paratypes: 71885b,e-m, 109386b-d.

Horizon and locality —Edinburg formation (Liberty Hall facies) in Virginia:
On Middle River, 4 mile north of Verona, Staunton (15’) Quadrangle; 500 feet
northwest of the entrance to Endless Caverns, Mount Jackson (15’) Quad-
rangle; Reservoir Hill, Wytheville; 2 miles northeast of Dale Enterprise, Har-
risonburg (15’) Quadrangle ; Lee Highway, 14 miles northeast of Harrisonburg,
Harrisonburg (15’) Quadrangle; 14 miles east of Tenth Legion, Mount Jackson
(15’) Quadrangle.

Rich Valley formation in Virginia: At Porterfield Quarry, 5 miles east of
Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

ELLIPTOGLOSSA SYLVANICA Cooper, new species
Plate 23, D, figures 7-13

Shell small, lustrous with alternating bands of light and darker brown, a little
longer than wide and with the greatest width at about the middle. Sides gently
rounded ; posterior and anterior margins about equally rounded. Umbonal re-
gion minutely radiate. Surface marked by fine concentric undulations.

Pedicle valve moderately convex in lateral profile ; strongly convex in anterior
profile and with the flanks gently concave in this profile. Brachial valve slightly
deeper than the pedicle one, a little more convex in lateral profile; flanks
flattened.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 245

Measurements in mm.—

Length Width Thickness

Holotypen (brachial valve)... sucesso sie 4.0 2.8 0.5?
Paratype (pedicle valve 109388a) ............ 3.8 2.4 ?
ou (brachial valve 109388c) ........... 3.4 2.5 ?

Types.—Holotype: 109388e; paratypes: 109388a,b,f-i, unfigured paratypes:
109388c,d.

Horizon and locality.—Sylvan shale (lower 40 feet) in Oklahoma: Middle
east side sec. 34, T. 1 S., R. 2 E., Murray County, Arbuckle Mountains. Maquo-
keta chert in Missouri: Decaturville, Camden County.

Discussion.—This species differs from E. ovalis in its rounder form, some-
what deeper and more convex valves and the narrower flattened margins, particu-
larly the posterior margin. On the exterior the minutely radiate umbo is distinc-
tive. Details of the interior of this species are also very difficult to determine
because of the thin shell.

Superfamily AcroTrETACEA Schuchert, 1896
Family ACROTRETIDAE Schuchert, 1913

Approximately circular shells with more or less elevated conical pedicle valves
with small, simple pedicle opening.

Subfamily AcrotreTINAE Matthew, 1903

Usually small shells with high conical pedicle valves having a small postapical
foramen ; brachial valve with marginal beak.

Identification of the genus Acrotreta is difficult and uncertain because the
interior details of the genotype are still unknown. The type species is known
to come from Ordovician rocks, a fact that may exclude many of the Cambrian
species referred to this genus. It is possible, too, that if the type species of Acro-
treta comes from the Kunda formation, it may actually have the same structure
as Conotreta which occurs in rocks of the same age. This point, too, cannot be
settled until the interior of the type species is known.

Solution of limestone in acetic acid has opened a new vista in the study of
these small and difficult shells. The Pratt Ferry limestone, Alabama, has proved
very prolific of a variety of acrotretids having complicated and unusual struc-
tures. It is probable that the same methods applied to other bituminous lime-
stones will produce a still greater variety of forms. This is proving to be true in
the Cambrian, from which a variety of novel forms has been taken.

Genus ACROTRETA Kutorga, 1848

Acrotreta Kutorca, Verhandl. Russ.-Kais. Min. Ges. St. Petersburg, for 1847, pp. 260, 275,
1848.

246 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ACROTRETA GEMMA Billings
Plate 22, E, figures 10, 11

Acrotreta gemma Biturncs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 216, figs. 201a-f,
1865.—Watcott, U. S. Geol. Surv. Mon. 51, p. 685, pl. 66, figs. 1a, b, 1912.

One specimen of two present in the National Collection is worthy of remark.
Both are pedicle valves, and one of them seems to be a perfectly normal indi-
vidual with a pseudointerarea and intertrough as described by Billings and
Walcott. The second specimen has a perfectly formed pseudointerarea, but the
median part of that surface is elevated to form a gradually widening ridge from
beak to base. The structure suggests the homoeodeltidium of the Paterinacea.
The structure is too regular to be a deformity, but more specimens are needed
to understand it.

Figured specimen.—116816a.

Horizon and locality Upper Table Head series in Newfoundland: At Table
Point Cove.

ACROTRETA MAGNA Cooper, new species

Plate 28, D, figures 9-12

Shell large for the genus, forming a depressed cone in profile; outline subellip-
tical; surface marked by fine concentric elevated lines.

Pedicle valve forming a posteriorly truncated cone in lateral profile; anterior
slope long and moderately convex ; beak posterior to the center; posterior slope
shorter than the anterior one, very steep and gently convex. Anterior profile
broadly convex and with convex sides. Apical angle 75°? Pseudointerarea
broad ; intertrough narrow and deep.

Brachial valve elliptical in outline with the width slightly greater than the
length; hinge wide and straight; posterolateral extremities narrowly rounded ;
sides gently rounded and anterior broadly rounded. Lateral profile gently con-
vex, with the maximum convexity in the umbonal region; anterior portion flat-
tened ; anterior profile broadly convex with the maximum convexity at the mid-
dle; lateral slopes long and gently concave. Median septum extending from the
posterior margin to about the middle of the valve; 2 large muscle scars located
on each side of the median ridge just anterior to the hinge are visible.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle valve) ........cceesceccees 5.5 6.8 2.7-+-
Paratype (brachial valve 109724b) ..........- 8.3 6.4 ?

Types.—Holotype : 109724a; figured paratype: 109724b; unfigured paratypes:
109724c-f,

Horizon and locality.—Boulders of the Mystic conglomerate in Quebec, Can-
ada; Range 6, Lot 20, 24 miles north of Mystic, Stanbridge Township.

Discussion.—This species has been assigned to Acrotreta rather than to Cono-
treta because of its earlier age than Conotreta and because only the bases of 2
pallial trunks could be distinguished. The extreme inner ends of the pallial trunks
only are visible, and no evidence of branching could be seen. Actually it cannot
be determined whether or not the trunks do branch.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 247

If this species does belong to Acrotreta, it is a fairly large form for the genus.
It is characterized by its depressed conical form and the low convexity of the
brachial valve. It is suggestive of Conotreta depressa but is a somewhat more
elevated cone than that form.

Genus CONOTRETA Walcott, 1889
Conotreta Watcott, Proc. U. S. Nat. Mus., vol. 12, p. 365, figs. 1-4, 1890 (extracts 1889).

The name Conotreta has long been known, but it has been applied to a single
species in this country. A few other species are known in Europe, but until this
study was undertaken the genotype was the only one known in this country.
In the description of the genus, Walcott made known the pedicle valve only.
Discovery of abundance of mineralized specimens in the Liberty Hall facies near
Lacy Spring, Va., and the limestone at Pratt Ferry, Ala., makes it possible to
describe and illustrate some fine interiors.

The pedicle valve is an irregular cone, the posterior side of the cone flattened
by the pseudointerarea but the anterior side usually convex. The posterior side
with the pseudointerarea is usually shorter than the anterior side. The side fac-
ing the brachial valve is thus oblique. The beak is small and usually smooth and
slightly curved in a posterior direction. It may, however, be bent slightly an-
teriorly as in C. plana described below. The foramen is minute and is located
very slightly posterior to the apex. The pseudointerarea often is simply a flat-
tened triangular area on the posterior face, ornamented in the same manner as
the rest of the valve. More often, however, it shows a slightly elevated central
track defined by shallow grooves down which a more or less shallow impressed
line extends. This impressed line is the intertrough, and it may extend from the
foramen to the margin or may be visible for a short distance only. Its function
is uncertain. In exfoliated specimens the intertrough shows more clearly. In
such specimens the median swollen portion of the palintrope is well shown and
is bounded by 2 grooves that represent slight thickenings or depressions that help
to support the portion of the palintrope that covers the pedicle region.

The foramen, although minute, leads into a pedicle groove of considerable
size that widens toward the brachial valve and opens into the interior posterior
to a pillar or boss of vesicular shell used to strengthen the apical region as the
valve grows. The pedicle aperture inside the valve is many times larger than the
foramen. The base of the pedicle was probably attached to the posterior surface
of the pillar.

One of the features that gave Conotreta generic status is the great develop-
ment in size and number of the pallial trunks in the pedicle valve. The 2 pri-
mary trunks, corresponding to the vascula media of Opik, originate on each side
of the pillar and by the depth of their insertion into the shell substance make
the pillar stand into bold relief. The major trunks branch more or less numer-
ously, chiefly by bifurcation, and may produce as many as 7 trunks on each side.

The musculature of the pedicle valve is difficult to determine, but two speci-
mens from the Liberty Hall facies show a pair of muscles located on each side
of the valve posterolaterally to the pedicle groove. The larger scar is located
farthest from the groove. One of these pairs probably corresponds to the cardi-

248 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

nal scar figured by Walcott in “Acrotreta.” Alabama specimens show large scars
just inside the posterior margin on the underside of the palintrope.

Brachial interior: The etched specimens from the Liberty Hall facies show
the interior of the brachial valve to perfection. The posterior quarter is thickened
to form a platform. At the apex a small triangular groove occurs that may have
served as a seat of muscle attachment. Just anterior to the groove and at each
angle occurs a large elliptical muscle scar. Inside these scars and at their anterior
end appear 2 small muscle scars. At the anterior end of the thickened platform
a thin elevated median ridge rises to a point slightly anterior to the middle and
then descends rapidly to the floor of the valve. The 4 muscle scars are the only
ones determined with certainty. It is possible that the median septum also was
a seat of muscle attachment, but no marks were seen on it to bear out this
suggestion. The large scars are the cardinals of Walcott, but no scars were seen
anterior to the posterior platform that could be interpreted as the centrals of
Walcott.

Conotreta is common in the Botetourt and Pratt Ferry formations and the car-
bonaceous limestones of the Liberty Hall facies in the belt between Harrison-
burg and Winchester, Va. Only one species of Conotreta is so far known from
pre-Botetourt rocks in the Appalachians. Elsewhere specimens having the outer
form of Conotreta are referred to the genus Acrotreta.

Conotreta cannot be regarded as a well-established genus until the internal char-
acters of Acrotreta are thoroughly known. The latter occurs in rocks equivalent
to those of the Black River-Trenton interval in Estonia, but its internal charac-
ters are not clearly known. The bases of 2 pallial trunks are visible in one of
the types, but the extent to which they branch is unknown. It is thus possible
that Acrotreta and Conotreta are synonyms, but the point cannot now be settled.

CONOTRETA ? ALTA Cooper, new species
Plate 16, A, figures 1-3

This species differs from all others known from Chazyan rocks by its very
narrow form and the great elevation of the pedicle valve. This species has an
apical angle of 30° and a lateral angle of 26°. It is thus the narrowest form
known. The pseudointerarea is narrow, but the intertrough is located on a low,
longitudinal elevation along the center of the pseudointerarea. Surface marked
by very fine concentric lines. The holotype lacks the apex but is I.g mm. long
along the anterior slope and 1.2 mm. long on the posterior face, width 1.7 mm.

Type.—Holotype: 109715.

Horizon and locality.—Arline formation in Tennessee: In glade 4 mile south-
east of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

CONOTRETA ? ALTIROSTRA Cooper, new species
Plate 18, G, figures 51-53

Shell small, long and slender, forming a slightly curved cone obliquely open
at the anterior end. Pedicle valve a slender cone with gently curved posterior

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 249

margin and moderately convex anterior margin; anterior profile with gently con-
cave sides; apical angle 35° to 40°; apex truncated, perforated by a minute
foramen. Pseudointerarea broad and flat ; intertrough narrow and extending for
the length of the valve.

Measurements in mm.—Holotype, length 1.5, width 2.0, thickness 3.5.

Type.—Holotype: 116812.

Horizon and locality—Botetourt formation in Virginia: Field on the south
side of the road, 0.2 miles east of Strasburg Junction station, Strasburg (15’)
Quadrangle.

Discussion—This species is distinguished from all the other conical forms
described by the extreme thickness or elongation of the valve in the direction of
the thickness. The beak is long and slender and the sides of the valve concave.
It is probable that this form and C. alta belong to a new genus. Correct assign-
ment will have to await the discovery of the brachial valve.

This species is suggestive of C. ? alta but differs in its larger size and the
slight curvature of the pedicle valve in lateral profile.

CONOTRETA APICALIS Cooper, new species
Plate 17, B, figures 15-28

Shell of about medium size for the genus, thick, dull dark brown in color;
obliquely conical in outline with the posterior side flattened ; shell margin nearly
circular; height or thickness equal to the width. Surface marked by growth
undulations and fine concentric lines.

Pedicle valve with apical angle of 43°; lateral profile with strongly convex
anterior margin; anterior profile with slightly convex lateral margins; beak
acutely pointed; foramen minute, apical. Posterior margin in lateral profile
gently concave; width of pseudointerarea about half the valve width.

Brachial valve slightly longer than wide; gently convex in lateral profile with
the greatest convexity located in the anterior part of the posterior third of the
valve; anterior two-thirds somewhat flattened; anterior profile broadly convex,
somewhat flattened medially and with short, gently sloping lateral slopes.

Pedicle interior: Foraminal cavity deep; pallial sinuses numbering 3 on each
side ; callosity just anterior to foraminal cavity small. Brachial interior with short
and narrow triangular depression; propareas small; median ridge extending
nearly to front margin, highest about one-half the length anterior to the posterior
margin where it attains a sharp point. Posterior part of septum with a crescent-
shaped smooth area located just anterior to the triangular depression.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle valve) ......... a 3.4 3.1 (posterior surface)
Paratype (brachial valve 116813c). 2.5 2.6 ?

Types.—Holotype: 116813a; figured paratypes: 116813b-g.
Horizon and locality —Pratt Ferry formation (lower 3 feet) in Alabama: 0.2
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

250 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion.—This species is suggestive of C. gigantea, but it is generally a
thicker shell, more slender, and with a smaller apical angle. It is an uncommon
species in the insoluble residues from Pratt Ferry.

CONOTRETA ? CONCENTRICA Cooper, new species
Plate 18, C, figure 22

Shell fairly large for the genus, represented by the pedicle valve only. Nearly
symmetrically conical in profile with the apex subcentral; lateral profile with
gently convex anterior slope and long steep, nearly flat posterior slope. Anterior
profile conical with gently convex sides; apical angle obtuse. Foramen apical,
minute. Apical half of shell marked by very fine concentric growth lines ; anterior
half marked by strong, regular, elevated concentric ridges which do not extend
over the pseudointerarea ; pseudointerarea broad and flat ; intertrough not clearly
discernible. Interior without visible structures. Accurate measurements not
possible.

Type.—Holotype: 116814.

Horizon and locality.—Lower 3 feet of the Pratt Ferry formation in Alabama:
0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This is the only species assigned to Conotreta which has strong
marginal corrugations. The ornamentation thus suggests that of Scaphelasma,
but the other features are quite different. It was not possible to ascertain the
interior structure; no apical callosity like that of Conotreta was seen, and it is
probable that this specimen represents a new genus. Until the brachial valve is
known, it is not possible to understand the true relationships of the genus.

CONOTRETA CUSPIDATA Cooper, new species
Plate 16, B, figures 4-7

Shell of moderate size; pedicle valve nearly circular in outline, lateral profile
a narrow wedge. Pseudointerarea triangular, occupying a little more than one-
third the width. Apical angle 60°; lateral angle 50°. Beak bent very slightly
posteriorly. Surface ornamented by concentric, low undulations and fine con-
centric lines.

Brachial valve almost circular, but with the posterolateral margins somewhat
shouldered; very gently convex in lateral profile. Median sulcus shallow and
narrow, practically obsolete at the front margin.

Measurements in mm.—Pedicle valve (109716a), posterior slope 2.5, anterior
slope 3.3, width at base of cone 3.1. Brachial valve (109716b), length 3.0, width
3:8.

Types.—Holotype: 109716a; paratype: 109716b.

Horizon and locality—Effna formation in Virginia: Porterfield Quarry, 5
miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—See Spondylotreta? declivis.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 251

CONOTRETA DEPRESSA Cooper, new species
Plate 17, C, figures 29-57

Shell large for the genus, elliptical in outline, pedicle valve depressed, conical,
with the posterior surface flattened; valves marked by fine concentric lines.
Color shiny light brown often with alternating bands of light and darker color.

Pedicle valve depressed, circular in outline except for the posterior margin ;
lateral profile gently convex; anterior slope long and swollen; posterior slope
short, flat; foramen small, apical; apical angle varying from about go° to 110°.
Anterior and lateral profiles showing strong, convex sides. Pseudointerarea
wide, measuring somewhat more than half the width; intertrough not visible or
showing a slight wave of the posterior margin or a faint longitudinal color band.

Brachial valve wider than long, fairly strongly convex in lateral profile, with
the greatest convexity in the umbonal region ; beak marginal, small and incurved ;
anterior quarter flattened ; posterolateral slopes gently concave. Anterior profile
broadly convex with the median region flattened slightly and with moderately
long and gentle lateral slopes.

Pedicle interior with a small callosity excavated anteriorly; pedicle chamber
moderately deep and narrow; pallial trunks deeply impressed at the rear, the
outside one the deepest and bifurcating near its point of origin; outside trunk
also bifurcating near the anterior edge of the callosity. Muscle scars well de-
veloped and located on the inner curved surface just outside the flattened inner
surface of the palintrope.

Brachial interior with a long median septum extending for about two-thirds
the valve length; septum rising to a point about one-third the length from the
posterior margin; posterior triangular depression short, small, inconspicuous ;
propareas attenuated. Two sets of muscles well developed, the larger ones lo-
cated just anterior to and outside the propareas, the smaller set located on each
side of the median septum opposite its highest point.

Measurements in mm.—

Length Width Thickness
Holotype) (Cpedicle: valve) wes «aid snd nia tin ospepehageiaeis 5.4 6.5 2.6
Paratype (brachial valve 116815c) ........... 4.9 5.9 ca. 0.5

Types.—Holotype: 116815e; figured paratypes: 116815a-d,f-m; unfigured
paratypes: 116815n; figured specimen: 117967.

Horizon and locality.—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This is a large species approaching C. magna and C. gigantea,
but the pedicle valve forms a much wider cone and the shell never attains the
great thickness of the other two species.

CONOTRETA GIGANTEA Cooper, new species
Plate 16, E, figures 18-23; plate 17, D, figure 58; plate 17, EF, figures 59, 60

Shell exceptionally large for the genus, circular in outline, forming a slightly
curved and elongate cone. Base of cone slightly wider than long. Apical angle

252 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

40° to 60°. Beak curved posteriorly above the pseudointerarea which is narrow
and one-half the width of the valve. Anterior side of cone strongly convex.
Lateral surfaces strongly rounded. Surface marked by fine concentric lines.

Brachial valve slightly elliptical, wider than long; posterior margin narrow,
nearly straight. Lateral and front margins strongly rounded. Lateral profile
unequally convex with a moderately convex umbo and posterior third; con-
vexity decreasing anteriorly to about two-thirds the length from the beak, where
the valve is flattened. From here to the front margin it is gently concave. Beak
marginal, protruding slightly posterior to the posterior margin. Median septum
extending to middle.

Measurements in mm.—

i Length Width Height
Holotype (pedicle valve) ................000- 5.0 6.8 6.3
Paratype (brachial valve 109734d)............ 8.0 7.8 ?

Types.—Holotype: 109734b; figured paratypes: 109734c,e, 117968a-c; un-
figured paratypes: 109734a,d,f-m.

Horizon and locality.—Pratt Ferry formation (lower 3 feet) in Alabama: 0.2
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—See Conotreta magna.

CONOTRETA MAGNA Cooper, new species
Plate 16, D, figures 11-17

Shell large for the genus, resembling C. gigantea but dull black in color;
pedicle valve forming an elongated cone; brachial valve nearly flat; surface
marked by crowded concentric undulations and fine lines of growth.

Pedicle valve with the thickness or height of the cone about equal to the width;
lateral profile conical with the posterior side flattened and slightly concave; an-
terior side moderately convex; anterior profile conical with very slightly convex
sides ; apical angle about 40°. Pseudointerarea narrow, measuring about 24 mm.
Intertrough shallow. Valve margin forming a circle. Interior unknown.

Brachial valve nearly circular, very slightly convex in profile with the um-
bonal region forming the most convex part; anterior half flattened; hinge line
narrow ; median ridge extending at least to the middle.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle valve) .........leshwe ceeds 7.0 7.4 7.8
Paratype (brachial valve 109732a)...........-. 5.7 6.2 ?

Types.—Holotype: 109733; figured paratypes: 109732a,b; unfigured para-
type: 109732c.

Horizon and locality—Whitesburg formation in Bulls Gap (T.V.A. 171-SE)
Quadrangle, in Tennessee: 2 miles west of Bulls Gap Station, 14 miles west of
Bulls Gap, and 24 miles southeast of Whitesburg.

Discussion—This species is most suggestive of C. gigantea but differs in its
proportions and other details. Conotreta magna has a smaller apical angle than

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 253

the Alabama shell, and the pedicle valve is less curved. The pseudointerarea
of the Tennessee species is much narrower than that of C. gigantea. The Ala-
bama species has the appearance of being a lower and wider cone than the Ten-
nessee shell.

CONOTRETA MULTISINUATA Cooper, new species
Plate 16, G, figures 28-40

Shell small, pedicle valve forming a low cone; brachial valve subcircular and
gently convex. Apical angle 70°; lateral angle 55°. Surface of both valves
marked by very fine concentric lines of growth. Pseudointerarea triangular,
equal in width to a little less than half the width of the valve. Lateral slopes from
the pseudointerarea narrowly rounded. Anterior slope convex. Beak bent slightly
posteriorly.

Brachial valve gently but unevenly convex in lateral profile and with the great-
est convexity in the umbonal region. Lateral slopes flat and gentle ; median sulcus
deep, narrow, and extending from the umbo nearly to the front margin.

Interior of pedicle valve marked by as many as 14 pallial sinuses that are
formed by the repeated branching of a main trunk situated on each side of the
pedicle tube. Median septum long, extending nearly to the front margin, high
and with its most elevated point at about the middle of the valve.

Measurements in mm.—Pedicle valve (109742g), length 2.3, width 2.8, pos-
terior slope 1.6, anterior slope 2.8, width of pseudointerarea 1.2. Pedicle valve
(109742f), length 2.7, width 3.2, posterior slope 2.4, anterior slope 3.1, width of
pseudointerarea 1.3. Brachial valve (109742c), length 1.8, width 2.0. (109742a),
length 2.2, width 2.0.

Types.—Holotype: 109746a; figured paratypes: 109739a, 109742f,h,p,r,
109746b-d; unfigured paratypes: 109736a-h, 109737a-c, 109738a,b, 109739b,
109740a-c, 109741a-k, 109742a-e,g,1-p,q,S-v.

Horizon and locality—Botetourt formation in Virginia: 14 miles southeast of
Harrisonburg, Harrisonburg (15’) Quadrangle.

Chatham Hill formation in Virginia: Bland County, Grayson Farm, 4 miles
southwest of Bland; 1 mile northwest of Lexington, Lexington (15’) Quad-
rangle.

Whitesburg formation in Tennessee: 2 miles south of Albany and 8 miles
northwest of Greenville, Mosheim (T.V.A. 181-NW) Quadrangle; 14 miles
west of Bulls Gap, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Pratt Ferry formation in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton
(15’) Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: In a field northwest
of U. S. Highway 11, 3 mile southwest of Lacey Springs, Broadway (15’) Quad-
rangle; southeast side of knob 1,000 feet east of Endless Caverns Entrance,
Mount Jackson (15’) Quadrangle.

Discussion—This species is suggestive of Spondylotreta? declivis and C. cus-
pidata. It differs from the former in its ornamentation because it does not have
the regular and fairly strong concentric lines characteristic of Spondylotreta?

254 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

declivis. It differs from C. cuspidata in having a less sharply pointed beak and a
larger apical angle.

In the Athens limestone on the northwest side of U. S. (Lee) Highway 11,
3 mile southwest of Lacey Springs, slabs can be obtained that contain many
specimens of this species. These specimens are sufficiently mineralized to with-
stand etching in dilute hydrochloric acid. Many fine specimens preserving the
details of the interior to perfection have been obtained.

CONOTRETA PLANA Cooper, new species
Plate 16, F, figures 24-27

Shell large for the genus, pedicle valve hemiconical in lateral profile; outline
almost circular except for the flattened posterior margin. Angle formed by flat-
tened area and anterior slope about 50°; apical angle about 70°. Pseudointer-
area broadly triangular, occupying more than half the width. Lateral slopes
from pseudointerarea narrowly rounded. Pseudointerarea gently procline; beak
bent a little anterior to the plane of the pseudointerarea.

Brachial valve unknown.

Measurements in mm.—Holotype, length 4.8, width 5.5, posterior slope 3.5,
anterior slope 5.0, width of pseudointerarea 3.2.

Types—Holotype: 109735b; unfigured paratype: 109735a.

Horizon and locality—Effna formation in Virginia: Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion—This species can be recognized by the broad, flat pseudointer-
area which occupies more than half the posterior surface. It differs in this re-
spect from all other species described herein.

CONOTRETA RUSTI Walcott
Plate 16, H, figure 41

Conotreta rusti Watcott, Proc. U. S. Nat. Mus., vol. 12, p. 365 (extract 1889), figs. 1-4,
1890.—HALL and CLarkE, Pal. New York, vol. 8, pt. 1, p. 104, pl. 4, K, figs. 16-21, 1892.

Types.—Lectotype: 18443a (fig. 1) ; paratype: 18443b.
Horizon and locality—Trenton limestone in New York: Trenton Falls.
Salona formation in Pennsylvania: At Salona.

CONOTRETA TRIANGULATA Cooper, new species
Plate 28, A, figures 1-4

Shell large for the genus, outline an irregular cone, nearly planoconvex; sur-
face exfoliated. Pedicle valve with elongate-oval cross section, short posterior
slope, and a long but steep anterior slope; lateral slopes steep; false interarea
narrow. Brachial valve elongate oval with posterior margin somewhat more
narrowly rounded than the anterior margin; nearly plane in profile.

Measurements in mm.—Holotype, length 9.9, brachial length 9.2, midwidth
8.8, thickness 5.4.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 255

Type.—Holotype: 117973.

Horizon and locality—Effna formation in Virginia: On the north side of
Virginia Highway 114, 7 miles northeast of Lusters Gate, near Blacksburg, Va.

Discussion.—This species suggests C. magna, depressa, and gigantea because
of its large size. It differs from the first and last in its much less elevated conical
form. It is more like C. depressa in its low conical profile but differs in having a
narrower false interarea and a nearly plane brachial valve.

SPONDYLOTRETA Cooper, new genus

(Greek spondylium, vertebra; tretos, opening)

Shell small, conical in profile, the cone flattened on the posterior side by a
prominent and broad pseudointerarea. Surface marked by regular, strong con-
centric elevated lines.

Brachial valve with slightly postapical foramen; pedicle tube entering valve
between a high median septum and the posterior inner surface ; pedicle tube con-
tinued along wall as a forked ridge dying out about half the distance to the
margin.

Brachial valve gently concave in both profiles; moderately sulcate; hinge re-
gion with a median triangular depression and thin, short plate anterior to it and
overhanging the space between the hinge margin and the median septum. Median
septum long, originating just anterior to the hinge margin and extending nearly
to the front margin, triangular in profile with the apex of the triangle just pos-
terior to the middle. Two large muscle marks occupy the posterolateral areas.

Genotype.—S pondylotreta concentrica Cooper, new species.

Discussion—This genus is quite unlike any of the others herein described in
its septate pedicle valve. The strong median septum evidently serves the same
purpose as the anteroapical callosity of Conotreta.

Some uncertainty exists as to the assignment of this concave brachial valve to
this genus, It is the only specimen like it recovered from this locality, and it is
marked externally like the pedicle valves to which it is assigned.

On the basis of its regularly concentric ornamentation Willard’s Conotreta
declivis is assigned with doubt to this genus. The interior of Willard’s species
is not known, and only two specimens occur in the National Collection.

SPONDYLOTRETA CONCENTRICA Cooper, new species
Plate 18, A, figures 1-7

Shell small, conical in profile with the posterior side flattened ; surface marked
by fairly strong, even concentric, elevated lines.

Pedicle valve a misshapen cone in lateral profile with the posterior side flat-
tened by the pseudointerarea ; anterior side gently convex ; apex bluntly pointed ;
apical angle about 85°. Anterior profile with sides gently convex. Beak very
slightly incurved and perforated by a small circular foramen. Pseudointerarea
broad and flat ; intertrough not clearly defined. Interior with a long pedicle tube
entering the valve just posterior to an erect and long median septum on the

256 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

anterior slope of the interior ; on the posterior the end of the tube is extended
along the inner surface of the valve as a forked ridge extending for more than
half the length. The forked ridge dies out gradually and expands slightly toward
the margin.

Brachial valve nearly circular ; gently concave in lateral profile; anterior pro-
file concave; valve deepest in the median region; posterolateral extremities de-
flected slightly in a brachial direction ; beak small; umbo narrowly swollen; valve
gently sulcate anterior to umbo. Interior with a triangular depression in the
median part of the hinge region and with a small, thin plate built anteriorly from
this depression ; propareas small; median septum originating just anterior to the
triangular depression and extending nearly to the front margin; median septum
broadly triangular in profile with its apex located just posterior to the middle.

Measurements in mm.—

pe

Length Width Thickness septal
Holotype (pedicle valve) ......... 2.0+ 2.0-+ 2.0 i
Paratype (brachial valve 116826c) . 2.7 B33 ? 0.7

Types.—Holotype : 116826a ; figured paratypes: 116826b,c.

Horizon and locality—Pratt Ferry formation (lower 3 feet) in Alabama: 0.2
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This species is characterized by its large size and broad apical
angle. It therefore differs markedly from S. ? declivis (Willard).

SPONDYLOTRETA ? DECLIVIS (Willard)
Plate 16, C, figures 8-10

Conotreta declivis WiLLarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 258,
1928.

Small, irregularly conical in outline and profile. Posterior slope gently con-
cave but anterior slope gently convex. Pseudointerarea wide, marked medially
by a fairly wide but shallow intertrough. Apical angle 55°; lateral angle 50°.
Posterior margin gently concave. Surface marked by strong, fairly regular
concentric lines.

Measurements in mm.—Pedicle valve, posterior slope 2.3, anterior slope 3.0,
width 2.7.

Types.—Holotype: M.C.Z. 8593; figured hypotype : 109727a ; unfigured hypo-
types : 109727b,c.

Horizon and locality —Effna formation in Virginia: McNutt Quarry, 12 miles
southwest of Bland, Burkes Garden (15’) Quadrangle.

Discussion.—This species is externally very close to C. cuspidata but differs
in having a slightly smaller apical angle and much stronger concentric ornamenta-
tion. It is a much smaller species than S. concentrica and has a much smaller
apical angle. It is referred to Spondylotreta on the basis of the even, concentric
ornamentation which is quite unlike that of Conotreta, although its interior is
unknown.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 257

TORYNELASMA Cooper, new genus

(Greek toryne, spoon; elasma, plate)

Small, acutely conical in profile; surface marked by fine concentric lines.

Pedicle valve with acute apex and minute apical foramen; pseudointerarea
not clearly marked; intertrough narrow, shallow, indistinct.

Brachial valve convex in lateral profile; median septum originating a short
distance anterior to the posterior margin and surmounted by a long, shallow,
spoonlike plate. Median hinge region with a short, shelflike plate overhanging
space between posterior end of spoon and posterior margin.

Genotype.—Torynelasma toryniferum Cooper, new species.

Discussion.—In its exterior features, particularly its profile, this genus is like
several others but is characterized by the extremely sharp beak. The spoon-
shaped plate on the median septum is, as far as known, unique.

TORYNELASMA MINOR Cooper, new species
Plate 18,1, figures 57-64

Shell minute, conical, pale yellow to brown in color, and marked by fine con-
centric lines.

Pedicle valve forming a fairly symmetrical cone with strongly oblique open-
ing; beak acute; apical angle between 30° and 40°; anterior margin gently
sinuate.

Brachial valve nearly circular in outline ; lateral profile gently convex ; anterior
sulcate ; posterior moderately swollen. Interior with a short, erect, spoon-shaped
plate set on a high median septum, both structures originating near the posterior
margin ; septum highest near the middle of the valve and not protruding anterior
to the anterior end of the spoon-shaped plate but extending as a sharp point
anterior to the anterior end of the spoon. Spoon-shaped plate short and flat. A
small circular muscle platform appears on each side of the thin posterior end of
the median septum.

Measurements in mm.—

Height
of

spoon

Length Width Thickness plate

Holotype (brachial valve) ....... 0.6 0.70 ? 0.4
Paratype (pedicle valve 116823d).. 0.64 0.75 1.06 ?

Types.—Holotype: 116823a; figured paratypes: 116823b-d; unfigured para-
types : 116823e-h.

Horizon and locality.—Pratt Ferry formation (lower 3 feet) in Alabama: 0.2
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This species differs from the preceding one in its smaller size
and the character of the spoon-shaped plate in the brachial valve. In this species
the plate is flatter, shorter, and more elevated than in T. toryniferum. Further-
more, the septum is quite different in this species in having its own pointed crest
anterior to the spoon-shaped plate, the anterior end of which is unsupported.

258 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

TORYNELASMA TORYNIFERUM Cooper, new species
Plate 9, C, figures 9, 10; plate 18, E, figures 28-36; plate 28, E, figures 13-16

Shell small, acutely and fairly symmetrically conical in profile; color shiny
straw-yellow ; surface marked by fine, concentric lines.

Pedicle valve fairly symmetrically conical in both profiles; margins almost
roundly elliptical, strongly oblique to the shell axis; posterior side convex in
cross section and thus without a conspicuous pseudointerarea; intertrough in-
conspicuous ; apical angle 35 to 40°.

Brachial valve roundly elliptical in outline; fairly strongly convex in lateral
profile; broadly convex in anterior profile; beak small, slightly protruberant.
Brachial interior with shelflike area, short but wide, extending anteriorly from
the hinge over the interior; spoon-shaped plate narrow posteriorly but widening
anteriorly to reach its widest point near the anterior end; median septum crested
anteriorly and reaching its highest point at its anterior extremity ; median septum
protruding slightly anterior to the anterior end of the spoonlike plate; spoon-
shaped plate characterized by a deep median area with a rim on each side set
off by a longitudinal suture line.

Measurements in mm.—

Height

Length Width Thickness aeataaa

Holotype (brachial valve) ........ rit 1.6 0.4 0.75
Paratype (pedicle valve 116824a).. 1.3 1.8 2.5 ?

Types.—Holotype: 116825c; figured paratypes: 116824a-c, 116825d-f; un-
figured paratypes: 116824d, 116825a,b,g,h.

Horizon and locality—Pratt Ferry formation (lower 3 feet) in Alabama:
0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This species is characterized by its fairly large size, the acutely
pointed pedicle valve, and the deep, spoon-shaped plate supported for its entire
length by the median septum. Besides its size, it differs in the latter respect from
T. minor in which the anterior end of the spoon-shaped plate is free and the
anterior end of the median septum forms a free point.

RHYSOTRETA Cooper, new genus

(Greek rhysos, wrinkled; tretos, opening)

Shells small, thick, conical in outline; surface of both valves marked by regu-
lar, closely spaced, concentric elevated rings.

Pedicle valve conical in profile; posterior side flattened to form a pseudointer-
area ; intertrough usually narrow, shallow. Foramen large, tear-shaped, with the
apex of the tear at the valve apex; foramen located just posterior to the apex.

Brachial valve nearly flat in both profiles but deeply concave anterior to the
umbo and in the median part of the valve; anterior rim often convex.

Pedicle interior without any trace of muscle marks or septa. Brachial interior
with a strong median septum arising a short distance anterior to the posterior
margin and extending to the front margin. Septum highest at its anterior end.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 259

Posterior margin straight and characterized by a pseudointerarea of considera-
ble length in old shells; pseudointerarea often growing as a shelf over posterior
end of median septum. Two large muscle scars occupy the posterolateral areas
on each side of the median septum.

Genotype.—Rhysotreta corrugata Cooper, new species.

Discussion.—This pretty little genus is characterized by its concave brachial
valve, the strongly corrugated exterior, and the fairly large tear-shaped pedicle
opening. Unfortunately, none of the numerous specimens obtained by solution
of limestone by acetic acid shows any details of the muscle system of the pedicle
valve.

The inside of the brachial valve is characterized by a strong median septum
that rises to its highest point at the anterior end of the valve. This septum origi-
nates near the middle of the valve in very young specimens. The small brachial
valve is also deeply concave, but as it grows, the anterior thickens and levels off
to form a flattened anterior rim. This rim in old shells may grow toward the
pedicle valve and produce a strongly convex rim.

RHYSOTRETA CORRUGATA Cooper, new species
Plate 18, F, figures 37-50

Shell small, thick, forming a cone with flattened posterior ; surface marked by
strong, rounded concentric rings.

Pedicle valve with anterior margin gently convex; posterior margin flat to
gently convex; lateral slopes strongly rounded ; anterior profile with very gently
convex sides; apical angle about 30°, pseudointerarea broad, flat but marked
by concentric corrugations, intertrough variable, broad to narrow but always
shallow ; beak blunt ; foramen large, located on the posterior side of the beak.

Brachial valve with nearly straight hinge line; beak small, protruding beyond
the posterior margin ; lateral profile flat to slightly concave ; anterior profile gently
concave ; median region deeply concave.

Measurements in mm.—

Length Width Thickness

Holotype (pedicle valve), °... .{s:s:1* 250-4 -ulaoet = ge) 1.6 1.0
Paratype (brachial valve 116817d) ........... 1.4 1.9 0.3

Types.—Holotype: 116817a; figured paratypes: 116817b-g.

Horizon and locality—Pratt Ferry formation (lower 3 feet) in Alabama: 0.2
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion——No other species is now known with which this one can be
compared.

SCAPHELASMA Cooper, new genus

(Greek scaphos, hollow; elasma, plate)

Shell small, elliptical in outline, conical in profile; surface marked by fine con-
centric lines and in the anterior half by imbricating lamellae.
Pedicle valve symmetrically conical in anterior profile but forming a cone

260 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

flattened on the posterior side in lateral profile; pseudointerarea broad; inter-
trough fairly wide and deep, extending to the beak; foramen small, located on
the posterior side of the beak at the place of origin of the intertrough, and having
a narrow, shallow groove anterior to it.

Brachial valve roundly elliptical in outline; flat to moderately concave in
lateral profile.

Pedicle interior with strong ridge on palintrope representing internal track
of intertrough; foramen surrounded by a thickened and elevated rim; brachial
interior with prominent median septum originating at the middle of the valve in
young specimens but never growing much farther posteriorly in the adult ; median
septum highest near the front margin, notothyrial region closed by a short but
prominent shelf.

Genotype.—Scaphelasma septatum Cooper, new species.

Discussion.—This genus is characterized by its fairly symmetrical conical form,
deep intertrough with foramen set in its anterior end and the median septum oc-
cupying the anterior half of the valve. In the latter respect it resembles Rhyso-
treta, but the septum never grows to the rear of the shell as in the latter genus.
It also resembles Rhysotreta in having the small shelf that grows anterior to
the beak of the brachial valve and overhangs the cavity between the median sep-
tum and posterior margin. Scaphelasma is quite unlike Rhysotreta in the size
of the foramen and the ornamentation.

SCAPHELASMA SEPTATUM Cooper, new species
Plate 18, J, figures 65-73

Shell small, generally straw-yellow in color, transversely elliptical in outline
and conical in profile. Surface in the umbonal region marked by fine concentric
lines ; but in the marginal region by strong undulations or imbrications.

Pedicle valve forming a symmetrical cone with convex sides in anterior profile ;
lateral profile conical with the beak slightly posterior to the center, the anterior
slope being flat to slightly convex and longer than the posterior slope ; posterior
slope steep and convex; intertrough wide, extending to foramen. Foramen lo-
cated somewhat posterior to the beak at the end of a narrow and shallow trough.
Interior as described for the genus.

Brachial valve with posterior half marked by fine growth lines only but an-
terior half imbricate with strong plaits. Lateral profile convex in the umbonal
region, becoming concave anterior to the umbo but convex again in the plaited
portion ; anterior profile nearly flat except for the median region which is gently
concave ; beak narrowly swollen and protruding posterior to the posterior mar-
gin; swollen umbonal areas extend anterolaterally to the plaited area; sulcus
originating just anterior to umbo and extending to anterior margin.

Measurements in mm.—
Length Width Thickness

Holotype (pedicle valve) 00.0050... cece cones 1.1 1.4 0.6
Paratype (brachial valve 116819h) ........... Te 1.4 0.3

FART «E CHAZYAN AND RELATED BRACHIOPODS—COOPER 261

Types.—Holotype: 116819a; figured paratypes: 116819b-h, unfigured para-
type: 116820.

Horizon and locality —The Pratt Ferry formation (lower 3 feet) in Alabama:
0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—No other species of this genus is available for comparison.

EPHIPPELASMA Cooper, new genus
(Greek ephippium, saddle; elasma, plate)

Shell minute, elongate conical in profile, surface marked by fine concentric
lines.

Pedicle valve elongate conical with apex curved in a posterior direction;
foramen minute, apical; pseudointerarea wide; intertrough indistinct; anterior
margin with slight sinuation. Interior not showing muscle scars.

Brachial valve gently concave, sulcate ; interior with a large complicated saddle-
shaped plate originating about one-third the length anterior to the posterior mar-
gin ; saddle-shaped plate bearing several prongs along its anterior borders, gen-
erally 5 in number. Hinge region with a small shallow triangular pit and narrow
propareas.

Genotype.—E phippelasma minutum Cooper, new species.

Discussion—No known genus is comparable to Ephippelasma. The only
genus known with a structure of the brachial valve similar to that of Ephip-
pelasma is Prototreta Bell, but in that Middle Cambrian genus the median plate
is constructed entirely differently.

EPHIPPELASMA MINUTUM Cooper, new species
Plate 17, A, figures 1-14

Shell minute, elongate conical in outline with the posterior side flattened ; sur-
face marked by crowded, fine, concentric lines.

Pedicle valve forming a misshapen cone in lateral profile with the posterior
side gently concave and the anterior side broadly convex; in anterior profile
the sides of the cone equal and slightly convex; anterior margin with a slight
emargination ; apical angle about 40°. Pseudointerarea broad with a faint nar-
row intertrough; beak incurved, foramen at the apex, minute.

Brachial valve with a nearly straight and wide hinge; roundly elliptical in
outline; later margins somewhat narrowly rounded; anterior margin broadly
rounded ; lateral profile nearly plane; anterior profile gently concave medially ;
median region of valve more or less deeply concave; umbonal region somewhat
narrowly swollen; beak small, protruding slightly posterior to the posterior mar-
gin. Sulcus broad and shallow, extending from anterior side of umbo to front
margin. Interior as described for the genus.

Measurements in mm.—

Height
of
dorsal
Length Width Thickness plate
Paratype (pedicle valve 116821d).. 0.6 0.75 0.9 ?

1 (brachial valve 116821f). 0.6 0.9 ? 0.6

262 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 116821a; figured paratypes: 116821b-i; unfigured para-
types: 116821j-1.

Horizon and locality—Pratt Ferry formation (lower 3 feet) in Alabama: 0.2
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species is characterized by its minute size, sulcate brachial
valve, and upturned pedicle beak. No other species of the genus is known, and
no other genus has a species quite like it.

UNDIFERINA Cooper, new genus

(Latin unda, wave; fero, bear)

Shell small, subrectangular in outline; hinge straight ; sides and anterior mar-
gin irregular; anterior margin often emarginate; surface marked by fine, con-
centric lines of growth; surface often thrown into irregular wrinkles and knobs.
Beaks small protuberant.

Brachial interior with median triangular depressed area at the hinge bounded
by short palintrope with narrow, triangular pseudointerareas ; triangular depres-
sion occupied by a short triangular plate ; small toothlike projections at anterior
edge of pseudointerarea; median ridge extending from a point just anterior to
triangular plate nearly to front margin; median septum highest at anterior end
with its free edge often modified into a narrow tube; muscle marks not clear,
but a large muscle seems to have been inserted just under the toothlike projec-
tions of the palintrope.

Genotype —Undiferina rugosa Cooper, new species.

Discussion.—This peculiar little brachiopod presents many unusual features.
Its exterior and outline are exceptional; the hinge region is not like any other
inarticulate ; and the median septum is often bizarre in its development.

The outline and exterior ornamentation suggest a brachiopod that may have
been attached. The irregular character of the exterior surface with its wrinkles
and knobs is suggestive of Crania, which often takes the surface ornamentation
of its host. The irregularity of the margins is similarly suggestive.

Not in accord with the above views is the straight hinge and the apparent
toothlike processes on each side of the triangular area. These are suggestive
of some sort of articular apparatus, but the valve seems to be a brachial valve
rather than a pedicle valve. The strong median septum and the triangular median
depression with its thin plate are features of the brachial valve of several genera
of inarticulate brachiopods described herein.

Full knowledge of this peculiar shell cannot be had until the pedicle valve is
known. If this valve should prove to be a cementing one, it may never be found
with the methods that are at present necessary in collecting this type of material.
If it is not a cementing form, it should ultimately be found as more etching is
done.

This genus in placed tentatively in the Acrotretinae because of the strong de-
velopment of the median septum, a feature of all known Acrotretinae.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 263

UNDIFERINA RUGOSA Cooper
Plate 18, B, figures 8-21

Shell small, subrectangular in outline with a straight hinge but irregular sides
and anterior margin ; sides generally somewhat narrowly rounded ; anterior mar-
gin usually broadly rounded, often irregular, sinuate or emarginate on one side.
Surface marked by fine concentric lines superimposed over irregular shell undula-
tions and knobs.

Interior as described for the genus.

Measurements in mm.—

Length Width Thickness
PEC CRRDERE | ea tier n & voccaas ay grt besa e) ous: viicuahoue ar oamicuaee 1.8 Bur 0.5
BORE NUT AERS TOA) is ci 6 eras. re se as erue. eee 2.0 2.6 0.5
ve UTMOSSZE) cwuieoece oleie ve ote Ore oes 1.9 2.6 0.6

Types.—Holotype: 116832b; figured paratypes: 116832a,c-f; unfigured para-
types : 116832¢,h.

Horizon and locality—Pratt Ferry formation (lower 3 feet) in Alabama: 0.2
miles southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—No other species is known to which this one may be compared.

Superfamily StIpHONOTRETACEA Schuchert and Walcott, 1908
Family SIPHONOTRETIDAE Kutorga, 1848

Usually oval shells with an oval or subcircular pedicle opening at the apex or
passing by resorption through the protegulum and umbo.

Genus SIPHONOTRETA Verneuil, 1845

Siphonotreta VERNEUIL, Geol. Russia, vol. 2, p. 286, 1845.

SIPHONOTRETA AMERICANA Cooper, new species
Plate 14, A, figures I-11

Shell small for the genus, oval in outline, ornamentation with posterior third
marked by fine, distant concentric lines and fine radial lines which develop a
spine at their intersection ; anterior two-thirds finely lamellose, each lamella bear-
ing one or more rows of fine spines, measuring slightly over 14 mm. at the front
margin.

Pedicle valve width equal to about two-thirds the length. Greatest width just
anterior to the middle; apical angle about 100°. Lateral margins broadly
rounded ; anterior margin somewhat narrowly rounded. Lateral profile moder-
ately strongly convex with the maximum convexity located in the umbonal re-
gion; anterior profile broadly but fairly strongly convex; posterolateral slopes
rounded and steep. Foramen, small, oval, about 1 mm. long and located just
anterior to the apex.

Brachial valve slightly longer than wide with strongly rounded margins and
gently convex profiles. Umbonal region sulcate, sulcus gradually widening an-

264 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

teriorly but barely perceptible or obsolete in the front half of the valve. Beak
smooth. Umbonal region marked by obscure concentric lines and indefinite radii.
Small spines numerous on all parts of the shell but confined to lamellae on the
front two-thirds.

Measurements in mm.—
Length Width Thickness

Holotype (pedicle valve) Toc y os. wee cee cee 8.3 6.8 2.0
Paratype (pedicle valve 100635) ............-- 8.6 8.0 1.8
(brachial valve 109636c) ........... 7.5 7.7 1.0
“ Ga eke Se PTOGOSOb Lane iuy Jone 9.1 8.4 ee

Types.—Holotype: 109636f; figured paratypes: 109635, 109636b,d,e,g; un-
figured paratypes: 109636a,c,h-m.

Horizon and locality——Arline formation in Tennessee: 4 mile southeast of
Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—The external expression of this species is like that of Schizambon,
but the two genera can be readily distinguished by the fact that the foramen of
Siphonotreta does not produce a long growth groove but is confined to the umbo.
No other species of Siphonotreta is known in these rocks to which S. americana
can be compared, but S. tertia of the Canadian (Sarbach) of Alberta is similar.
The latter species differs from the one described herein by the finely papillose
exterior and the absence of strong concentric lines.

Genus SCHIZAMBON Walcott, 1884

Schizambon Watcott, U. S. Geol. Surv. Mon. 8, p. 69, 1884—HALt and CLarKE, Pal. New
York, vol. 8, pt. 1, p. 113, 1893.—ULRIcH and Cooper, Geol. Soc. Amer. Special Pap. 13,
p. 60, 1938.

This is generally a rare or unusual genus in the rocks above the Cambrian,
but in the Southern Appalachians and at the Rock Crossing of Hickory Creek
in Criner Hills, Okla., it is fairly common. Although the collection studied for
this monograph is probably larger than any other of this genus ever brought
together, it is nevertheless quite inadequate for a detailed study of the interior
characters of this peculiar brachiopod. Although a question mark has not been
placed after the generic name of any of the species referred to Schizambon in
this book, it is doubtful if any of them are congeneric with S. typica of the
Pogonip (Goodwin) formation. All these species conform to the present generic
description, but that is obviously inadequate.

Several differences between the Cambrian and Lower Ordovician Schizambons
on the one hand and the Post-Canadian ones on the other are easily observable.
All the Marmor-Trenton species observed by the writer are 2 or 3 times larger
than the earlier ones, and the ornamentation is more elaborate. Furthermore,
as pointed out by Hall and Clarke, no long pedicle tube occurs on the inside of
the genotype as it does in S. canadensis and in some of the species described
herein. The beginnings of such a tube is shown in S. borealis Ulrich and Cooper.

The few specimens of Post-Canadian Schizambon in the National Museum
collection that show the internal surface or are impressions of that surface fail

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 265

to show any details of the musculature or pallial impressions. One brachial valve,
plate 15, C, figure 7, gives indications of a median ridge, but the structure is
badly crushed and it is impossible to make sure of its details.

A few specimens show the posterior margin fairly well. This margin on the
pedicle valve swells slightly in an anterobrachial direction and fits into a slight
reentrant anterior to the beak on the margin of the brachial valve.

Schizambon, even though locally fairly common, ranges too high vertically and
is generally too rare to be of great value in stratigraphy. It occurs in all types
of matrix from the calcarenite marbles to the black limestones and shales of the
Liberty Hall facies.

SCHIZAMBON CUNEATUM Willard
Plate 15, E, figures 20-22

Schizambon cuneatus WILLARD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 257,
pl. 1, fig. 4, 1928.

Shell large for the genus, suboval in outline, and with the valves unequal in
depth and outline. Lateral margins gently rounded; anterior margin narrowly
rounded. Greatest width at about the anterior third.

Pedicle valve slightly convex in lateral profile, broadly convex in anterior pro-
file. Track of foramen widening gradually, in length equal to about one-third
the valve length. Median region from foramen nearly to front margin slightly
swollen. Lateral slopes short and moderately steep. Area surrounding pedicle
groove marked by closely spaced, elevated concentric lines. Anterior two-thirds
marked by pairs of concentric bands. Spines slender, about 2 mm. or less in
length.

Brachial valve nearly circular in outline, gently convex in both profiles. Sulcus
originating at beak, shallow, widening gradually anteriorly to the front margin.
Sulcus defined by 2 distinct but narrow costae. Flanks gently convex. Umbonal
region marked by small spines arranged alternately, the space between each spine
marked by a fine elevated line, the radial and concentric elements producing a
very fine cancellation. Anterior to the umbonal region valve marked by paired
concentric bands.

Measurements in mm.—

Length Width Thickness
Hetorype ‘(pedicte valve) °2. 00. FP ee aes 14.2 12.8 ?
Hypotype (brachial valve 109668) ........... 12.4 13.5 ?

Type.—Holotype: M.C.Z. 8588; hypotype: U.S.N.M. 109668.

Horizon and locality—Effna formation in Virginia: McNutt’s Quarry, 12
miles southwest of Bland, Burkes Garden (15’) Quadrangle; Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Botetourt formation in Virginia: Hays Creek, 2 miles northwest of Browns-
burg, Lexington (15’) Quadrangle.

Discussion—This species is most like S. macrothyris but differs in having a
smaller and more symmetrical pedicle groove, not having radial elements in the

266 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ornamentation about the pedicle groove and in having the anterior two-thirds
marked by concentric lamellae in pairs.

SCHIZAMBON DUPLICIMURATUM Hudson
Plate 13, D, figure 6; plate 15, B, figures 5, 6

Schizambon duplicimuratus Hupson, Rep. New York State Paleont. for 1903, p. 284, pl. 5,
figs. 6, 7, 1904.—Raymonp, Ann. Carnegie Mus., vol. 7, No. 2, p. 228, pl. 34, figs. 23-24,
I911.—T WENHOFEL and WHITING, Geol. Soc. Amer. Special Pap. 11, p. 45, pl. 7, fig. 16,
1938.

Figured specimens.—117954; A.M.N.H. (no number).

Horizon and locality—Crown Point formation in New York: At Crown
Point, Valcour Island, and Chazy.

Mingan formation: Mingan Islands, St. Lawrence River, Quebec.

Discussion.—This species suggests S. cuneatum in the presence of paired con-
centric lines, but it is smaller, rounder, and the median sulcus of the brachial
valve does not reach the margin.

A pedicle interior in the collection is referred to this species, but the struc-
tures are not well preserved. The foramen is located about 2 mm. anterior to
the posterior margin and enters the valve in the median part of a considera-
ble callus development occupying the posterior half. Anterior to this callus and
near the lateral margins occurs a pallial trunk. Muscle marks are not clearly
visible. The specimen comes from the St. Martin formation, $ mile north of
Cap St. Martin, Quebec, Canada.

SCHIZAMBON HIRSUTUM Cooper, new species
Plate 15, D, figures 18, 19

The material on which this species is based consists of a fragmentary pedicle
valve and a nearly complete brachial valve. The specimens are large for the
genus. The remains of the pedicle valve indicate an ovate shell with a long and
large foramen and pedicle growth track. The brachial valve is nearly circular
in outline as usual for the genus. The median sulcus is narrow but deep in the
umbonal region, widening anteriorly and becoming lost in the general convexity
of the valve near the middle. The surface of both valves is marked by many
moderately closely spaced lamellae that are ornamented by numerous crowded
and very small spines, measuring about 2 mm. in length. The holotype (brachial
valve) is 12 mm. long, but probably at least 3 mm. are missing from the anterior ;
width 11.8 mm.

Types.—Holotype: 109670a; paratype: 109670b.

Horizon and locality.— Murat formation, Whistle Creek, Va.: Along road and
ridge, 2 miles northwest of Lexington, Lexington (15’) Quadrangle.

Discussion.—This species is suggestive of S. cuneatum but differs in having
concentric rows of fine spines and in not showing the paired concentric lines char-
acteristic of that species.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 267

SCHIZAMBON IRREGULARE Cooper, new species
Plate 14, C, figures 20, 21

This species is represented by a single brachial valve that may be distinguished
from all other members of this genus by the irregularity of its surface markings.
It is subcircular in outline, moderately convex in profile with the strongest curva-
ture at the middle. The lateral profile is moderately convex with maximum
convexity at the middle; anterior profile gently and broadly convex. The umbo
is smooth; the umbonal region is traversed by a shallow but wide sulcus which
disappears at about the posterior third. The posterior half of the valve is with-
out imbrications but is marked by discontinuous short and wavy lines and scat-
tered spines. The spines are about 1.5 mm. in length.

Measurements in mm.—Holotype, length 12.0, width 12.0.

Type.—Holotype: 109669.

Horizon and locality—Arline formation in Tennessee: On Sevierville Pike,
3 miles southeast of Knoxville, Knoxville (T.V.A. 147-NW) Quadrangle.

SCHIZAMBON LINEATUM Cooper, new species
Plate 14, D, figures 22, 23

A single brachial valve has unusual characters that separate it from all other
known species of the genus. The convexity in lateral profile is moderately strong
and the outline is oval, the shell narrowing posteriorly. In anterior profile the
valve is broadly convex. The median portion is somewhat swollen and the de-
scent to the margins is short but moderately steep. The ornamentation consists
of strong lamellae as is usual for the genus, but the lamellae are ornamented by
elevated, wavy concentric lines, often as many as 3 or 4 lines to a lamella. Large
spines occur scattered over the surface, but fine nodes on the concentric lines
indicate that rows of fine spines covered the entire shell. At the front margin
the fine spines have a length of 2 mm.

Measurements in mm.—Holotype, length 16.0, width 14.5, thickness 3.5.

Type.—Holotype: 109671.

Horizon and locality—Wardell formation in Virginia: I mile northeast of
Rye Cove, Clinchport (T.V.A. 188-NW) Quadrangle.

SCHIZAMBON MACROTHYRIS Cooper, new species
Plate 15, A, figures 1-4; plate 22, L, figures 22-24

Shell large for the genus, elongate, oval in outline; posterior pointed, lateral
margins gently rounded, anterior margin broadly rounded. Greatest width at
about anterior third.

Pedicle valve gently convex in the umbonal region, very faintly convex in the
anterior two-thirds. Track of foramen equal in length to one-third the length
of the valve, widening rapidly. Foramen elliptical. Region about the pedicle
track ornamented by nearly equally distant, elevated concentric lines which are
crossed by fine discontinuous radial lines occupying the entire umbonal region.

268 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Anterior two-thirds ornamented by lamellae bearing spines of 2 sizes, many small
spines and a few large ones; last 3 lamellae at the front crowded together.

Brachial valve strongly convex in anterior profile and moderately strongly
convex in lateral profile. Sulcus deep but narrow in the umbonal region, widen-
ing anteriorly for about one-third the length and then disappearing. Umbonal
region for about one-third its length marked by distant elevated concentric
threads and moderately crowded large spines. Lamellae of anterior two-thirds
moderately distant, provided mainly with large spines. Small spines few.

Measurements in mm.—Holotype, length 15.8, width 13.2, thickness 8.5.

Types.—Holotype: 98204a; figured paratypes: 116928a-c.

Horizon and locality—Wardell formation in Virginia: Lloyd Carter’s barn,
3 mile by road northeast of Rye Cove, Clinchport (T.V.A. 188-NW) Quad-
rangle; south of road, 4 mile east-northeast of Belfast Mill, Saltville (T.V.A.
212-NE) Quadrangle; 4 mile northwest of Rockdell, Elk Garden (T.V.A.
212-NW) Quadrangle; 13 miles west of Rye Cove, Clinchport (T.V.A.
188-NW) Quadrangle.

Benbolt formation in Virginia: Behind Brick Church west of Rye Cove,
Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—This species in size and outline is very like S. cuneatum, but it
differs in having an unusually large and wide foramen, the median sulcus of the
brachial valve is faint and scarcely reaches the middle, while the ornamentation
consists of strong, thick lamellae.

SCHIZAMBON PERSPINOSUM Cooper, new species
Plate 15, C, figures 7-17

Shell of moderate size for the genus; oval in outline with the length slightly
greater than the width. Lateral and front margins strongly rounded ; apical angle
about 120°.

Pedicle valve with posterior two-thirds slightly swollen and gently convex,
anterior third flattened or depressed to produce a slight inward bend. Beak
blunt, pedicle track extending for about one-third valve length. Foramen large
and oval. The region about the beak is ornamented by evenly spaced, elevated
concentric lines. Anterior to the beak the lamellose structure of the shell be-
comes pronounced, and the concentric lines, though still present, become less and
less numerous anteriorly.

Brachial valve elongate ovate in outline with moderately rounded lateral mar-
gins and narrowly rounded anterior margin. Lateral profile gently convex with
a slight geniculation toward the pedicle valve in the anterior third to half. An-
terior profile moderately but unevenly convex, the lateral portions incurving nar-
rowly. Posterior half ornamented by elevated discontinuous and wavy concen-
tric lines which are interrupted by scattered large spines. In the anterior half
the valve becomes lamellose, the concentric lines become fewer and disappear.
Each lamella bears on its edge long, hollow spines up to 6 mm. in length.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 269

Measurements in mm.—

Length Width Thickness
Holotype, (pedicle valve)... ¢ sr.0s0's cee ose 11.0 9.6 1.5
Paratype (brachial valve 109681b) ......... 14.2 14.1-+ ?
“ Gib aft He MEOGOSIG)* Lav cshas 12.5 10.7 re

Types—Holotype: 1o968ic; figured paratypes: 71891a, 109678, 109680,
109681a,d; unfigured paratypes: 71891b-d, 109679a,b, 109681b,e,f ; figured speci-
men: 109688.

Horizon and locality—Bromide formation (Pooleville member-O-roplecia
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek about center
Sec. 45; 1-5 3:, Rv E., Criner Hills, Carter County ; (zone 5), Spring Creek,
N$ sec. 17, T. 2 S., R. 1 W., Murray County.

Bromide formation (Mountain Lake member) in Oklahoma: Brownish granu-
lar beds, Rock Crossing, as above.

Discussion.—This species is fairly common in the Criner Hills and is charac-
terized by moderate size and very long spines. In these respects it differs from
S. canadensis (Ami) which is a large species, and also from S. dodgei in which
the spines are reported as only 2 mm. in length. The pedicle umbo is faintly
radiate as in S. subradiatum, but the latter is a much smaller shell with a more
convex pedicle valve and different anterior ornamentation.

SCHIZAMBON SUBRADIATUM Cooper, new species
Plate 14, B, figures 12-19

Shell of about average size for the genus, a little wider than long. Apical angle
about 110°. Lateral margins of adults strongly rounded; anterior margin more
gently rounded.

Pedicle valve oval; faintly convex in the posterior half but becoming flat and
very gently concave in the anterior portion. Length of pedicle track about one-
third the length of the valve. Beak pointed; posterior slope steep. Region about
the pedicle track and foramen marked by elevated, closely spaced, somewhat
wavy concentric lines. A few obscure radial lines extending from the beak to
a point opposite or a little anterior to the foramen. Spine-bearing lamellae closely
spaced.

Brachial valve subcircular in outline with both profiles moderately convex.
Sulcus narrow and deep at the point of its origin at the beak, widening very
gradually to the middle of the valve and becoming merged into the flattened an-
terior third. Posterior third with distant and subdued concentric lines and a
few spine bases. Beak and umbo smooth. Lamellae distant; spines numerous,
about 1.5 mm. in length.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle valve) ..............0.005- 9.4 8.6 ?
Paratype (pedicle valve 109685a)............. 8.8 77 1.8

id (brachial valve 109686a) ........... ye 7.9 ?

270 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 127

Types.—Holotype: 109686c ; figured paratypes: 109686d,e,g ; unfigured para-
types: 109685a,b, 109686a,b,f,h-1.

Horizon and locality Arline formation in Tennessee: About 4 mile southeast
of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—This species is characterized by the faint radii on the umbo sur-
rounding the pedicle groove and by the small size of the spines. It is suggestive
of a small S. cuneatum but is less oval than that species and is usually much
smaller and with shorter spines.

SCHIZAMBON sp. 1
Plate 21, A, figures 1, 2

The specimen illustrated is probably the young of one of the larger forms of
Schizambon from the Effna formation, but it is not possible to make an accurate
specific determination. The specimen shows some details of the interior, especi-
ally the elevated rim around the elongate track of the pedicle opening.

Figured specimen.—123306.

Horizon and locality—Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

SCHIZAMBON sp. 2
Plate 21, B, figures 3-6; plate 22, J, figure 17

Abundant in the washings from the acetic acid digestion of the Pratt Ferry
limestone from Pratt Ferry, Blocton Quadrangle, Ala., are numerous specimens
of a small Schizambon. The pedicle valves generally occur as only the posterior
parts, and usually the foramen does not show any marked growth toward the
anterior. For this reason and because of their small size the specimens are re-
garded as youthful. Young characters are also to be seen in the ornamentation
of the pedicle valve which has strong radii extending from the beak to the an-
terior margin. The interior of the pedicle valve shows few characters. The
foramen enters the interior at the posterior of a somewhat thickened umbonal
region. The sides of the foramen are often thickened slightly, but no trace of
muscle or pallial marks is visible.

The brachial valve has strong concentric lamellae and a more or less deep
sulcus extending from the beak to the anterior margin. On the inside the path
of the sulcus is shown as a low ridge on the interior. A large subcrescentic
muscle scar appears on a side of the median ridge near the middle of the valve.

Figured specimens.—109687, 11682ga-d.

Superfamily DiscinacEa Waagen, 1885
Family TREMATIDAE Schuchert, 1893

More or less circular shells in which the margin of the pedicle valve is notched
for the extrusion of the pedicle; brachial valve subconical.

Genus TREMATIS Sharpe, 1847

Trematis SHARPE, Quart. Journ. Geol. Soc. London, vol. 4, p. 66, 1847.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 271

TREMATIS ELLIPTOPORA Cooper, new species
Plate 11, H, figures 15-21

Shell small for the genus, represented by fragmentary specimens only; sub-
circular in outline with the surface marked by large, longitudinally elliptical pits
increasing in size anteriorly. Pedicle valve subcircular in outline with a deep
semicircular notch; beak concave, umbonal region gently concave, the concavity
lessening anteriorly and laterally. Pedicle notch triangular, longer than wide, oc-
cupied by a deeply concave plate; actual pedicle opening wide and short, some-
what semicircular in outline. Brachial valve with swollen umbo and beak pro-
truding slightly beyond the posterior margin; lateral profile moderately convex ;
umbonal slopes steep; median region swollen; anterior profile broadly convex
and with steep lateral slopes.

Interior of pedicle valve with thickened ridge representing the strengthened
inside of the concave plate; brachial interior with thickened posterior margin
having a more or less deep triangular pit under the beak. Musculature not pre-
served in either valve. All specimens too incomplete to measure.

Types.—Holotype: 116809c; figured paratypes: 116809a,d; unfigured para-
types: 116809b,e-h.

Horizon and locality —Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species is characterized by the large size of the pits which
are a feature of the ornamentation. The pits are elliptical or oval in outline with
the long axis parallel to the shell length. The elevated space between pits is
relatively broad. Pits on the umbo are very small. The arrangement of pits is
crudely quincuncial. The large size and form of the pits separate the species
from other described forms.

A note about the pedicle valve is necessary because it is not certain that it
belongs to this species. In color it is dark yellow like that of some of the other
specimens which range from dark yellow to light brown. The pedicle valve is
very thick shelled, which is another point in accord with the brachial valves to
which it is assigned. The ornamentation, however, is not like that of the brachial
valves. The pedicle valve shows small pits suggesting the youthful ornamenta-
tion of the umbonal region of the brachial valves. This ornamentation is very
lightly impressed and does not occur around the margins. Possibly the orna-
mentation is preserved only on the more youthful parts of the pedicle valve.

The species is represented by fragmentary material only, consisting of several
brachial valves but only the single pedicle valve.

TREMATIS FOERSTEI Cooper, new species
Plate 19, D, figures 15-19
T. huronensis Forrste (not Billings), Bull. Sci. Lab., Denison Univ., vol. 19, No. 3, p. 203,
1920.

Shell of about medium size for the genus, nearly circular in outline, lenticular
in profile. Surface marked by stout radial lines, and concentric elements that de-

272 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

fine rows of small circular to quadrangular pits. Three to four rows of pits occu-
pying 1 mm. at the front margin. Pits crudely concentric in arrangment but often
upset by intercalations offsetting the pits enough to make one or more rows of
pits appear opposite the crossbars in other rows.

Pedicle valve unevenly convex in lateral profile with the greatest convexity
in the umbonal and median regions; anterior third flattened. Apex located about
one-fourth to one-third the length anterior to the brachial beak or about one-
fifth to one-sixth the length anterior to the posterior margin. Foramen short,
semielliptical, about 4 mm. wide on the posterior margin and 3 to 4 mm. long,
or in other words one-fifth to one-sixth the length. Umbonal region rounded,
posterior slope steep, anterior slope long and flat, moderately steep. Lateral
slopes flattened, moderately steep.

Brachial valve moderately convex in lateral profile but slightly more convex
in anterior profile. Beak small, incurved; umbo narrowly swollen with steep,
concave but short umbonal slopes. Median region somewhat inflated ; lateral and
anterior slopes gentle but the lateral ones the steeper.

Measurements in mm.—

Length Width
Length Width foramen foramen Thickness

Paratype (pedicle valve 109709c).. 16.7 18.6 2.5 4.5 ?
- (1007070). cc sec Fe eres 18.5 20.3 2.5 5.0 6.0

Types——Holotype: 109707d; figured paratypes: 109709a,d; unfigured para-
types : 109707a-c,e,f, 109709b,c,e.

Horizon and locality—Upper to feet of the Plattin group (Macy formation)
or Barnhart formation in Ralls County, Mo.: Yaeger Farm, 54 miles southeast
of New London; Buford Cave on the M. F. Meyer Farm, 2 miles west and 4
mile north of New London; Conns Ford in the bed of Salt River about 4 miles
northwest of New London in NW. corner sec. 33, T. 56 N., R. 5 W.

Discussion—An examination of the figures of T. huronensis Billings shows
that the Ralls County specimens under discussion are not conspecific. In the first
place T. huronensis is a small species about 4 inch or slightly more in length and
4 inch or less in width. The pedicle valve is strongly concave, which incidentally
may not be a faithful representation of the true condition of the species. The
foramen of T. huronensis is figured as elongate, a deep and narrow gash in the
posterior half of the shell that extends to the apex. These features combined with
the more elongate form show clearly that the Ralls County specimens are not
correctly identified with T. huronensts.

Comparison of the Missouri specimens with T. ottawensts is more difficult be-
cause only the brachial valve is known with certainty. The pedicle aperture of
the pedicle valve figured by Hall and Clarke is a doutbful identification and can-
not be relied upon. The brachial valve as indicated by Billings is a large shell,
far larger than any of the Ralls County specimens. The ornamentation indicated
by Billings is that of quadrangular pits opposed by the crossbars of adjacent
series. The probability is that these are too regularly arranged in this fashion in
the drawing. The few specimens of this species available for comparison show

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 273

slender, elevated radii and short concentric dashes forming the quadrangular pits,
some of which appear opposite crossbars or opposite pits, patches of each oc-
curring on the same shell. This feature is not unlike the ornamentation of
T. foerste, but in that species the radial and concentric elements are not elevated,
but are flattened.

Some features of T. foerstei such as the ornamentation and size are sugges-
tive of T. punctostriata Hall from the Saltillo limestone at Clifton, Tenn., but
T. foerstei has more convex brachial valve, stronger ornamentation, and an
unrestricted foramen.

TREMATIS HURONENSIS Billings

Trematis huronensis Butuincs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 53, fig. 59
(adv. sheets 1862), 1865; Geol. Canada, p. 159, fig. 130, 1863—Lestey, Geol. Surv.
Pennsylvania, Rep. P 4, p. 1198, figs., 1880.

Horizon and locality.—Black River limestone, Pallideau Islands, Lake Huron.

TREMATIS MINNEAPOLIS (Sardeson)
Productella minneapolis SARDESON, Minnesota Acad. Nat. Sci., Bull. 3, p. 332, pl. 4, figs. 11,
12, 1892.
Trematis huronensis ScHucHERT (not Billings), Winchell and Schuchert, Geol. Minnesota,
vol. 3, p. 368, fig. 29, 1893.

Horizon and locality—Decorah formation (Spechts Ferry member-Sticto-
porella bed), Minneapolis, Minn.

TREMATIS PARVA Cooper, new species
Plate 19, E, figures 12-14

Species represented by three brachial valves only; small, broadly elliptical in
outline; sides narrowly rounded, anterior margin broadly rounded. Gently con-
vex in both profiles. Beak small, marginal, incurved. Umbo narrow, smooth,
with a shallow sulcus originating at its anterior end; sulcus continued forward,
widening gradually to the anterior margin. Posterolateral slopes to the margins
steep. Lateral slopes moderately steep but anterior slope long and fairly gentle.
Flanks bounding sulcus somewhat swollen. Surface marked by deep circular
pits arranged in quincunx.

Measurements in mm.—Holotype, length 3.7, width 4.7.

Types.—Holotype: 109703; figured paratype: 109705a; unfigured paratype:
109705b.

Horizon and locality.—Chatham Hill formation in Virginia: Grayson Farm,
north slope of Walker Mountain, 4 miles southwest of Bland, Bland County.

Lower Whitesburg formation in Tennessee: 4 mile west of Bulls Gap, Bulls
Gap (T.V.A. 171-SE) Quadrangle.

Discussion—This species is characterized by its small size and the quincun-
cial arrangement to the deep pits on the surface. The ornamentation is not quite
like that of any other American species of the genus, and it is possible that the

274 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

pedicle valve when found will indicate a new genus. The definite median sulcus
is another feature quite unlike that of Tremaits ss.

TREMATIS ? SPINOSA Cooper, new species
Plate 11, I, figures 22-24

Known from the brachial valve only ; thin shelled, light to dark brown in color,
subcircular in outline ; lateral and anterior margins strongly rounded ; gently con-
vex in lateral profile and with the greatest convexity in the umbonal region;
anterior profile broadly convex with moderately steep slopes and swollen median
region. Surface marked by densely crowded pits; margin marked by fine hair-
like spines ; spiny margins preserved in late growth varices. Interior with a small
concave plate overhanging the umbonal cavity.

Type.—Holotype: 116810.

Horizon and locality—Pratt Ferry formation: 0.2 mile southeast of Pratt
Ferry, Blocton (15’) Quadrangle.

Discussion.—This peculiar little shell is most closely allied to T. ? parva from
the Grayson Farm in Virginia, although no spines were seen on the Virginia
shell.

TREMATIS sp. 1
Plate 27, D, figure 9

This species is represented by two poorly preserved brachial valves that have
somewhat the shape of T. parva but in which the pits, where visible, are more
like those of true Trematis arranged in rows between longitudinal costellae. The
best specimen is small, slightly wider than long, with a marginal beak and nar-
row, prominent umbo. The convexity is moderate in both profiles.

Measurements in mm.—117970, length 4.2, width 4.7.

Figured specimen.—117970.

Horizon and locality—Whitesburg formation in Tennessee: 4 mile west of
Bulls Gap ; 24 miles southeast of Whitesburg, Bulls Gap (T.V.A. 171-SE) Quad-
rangle.

TREMATIS sp. 2

A second undescribed species of Trematis is indicated by five specimens, all
brachial valves, from Whitesburg formation in the railroad cut 1 mile south-
west of Otes, Bulls Gap (T.V.A. 171-SE) Quadrangle, Tenn., where it occurs
with Ectenoglossa nymphoidea. This species is strongly convex in both profiles
and quite oval in outline. The greatest width is located anterior to the middle.
The beak is strongly incurved and the umbo convex. The median portion is
swollen and all the slopes to the margins are fairly steep. The costellae are
very fine. Adjacent pits, in general, are arranged alternately, a pit falling oppo-
site a crossbar. About 12 costellae appear at the front margin in the space of
I mm.

Described specimens.—109702a-e.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 275

TREMATIS sp. 3
Plate 19, C, figures 10, 11

This third species is represented by a fragment of the brachial valve preserving
the umbonal region and part of the right side. The species is characterized by
its broad umbo, the strong convexity, and broad flat costellae separating rows
of longitudinally elliptical pits. The specimen was taken from the base of the
Lower Edinburg formation (Cyrtonotella zone) in Virginia: about 4 mile east
of Strasburg Junction, Strasburg (15’) Quadrangle.

Figured specimen.—109704.

Genus SCHIZOCRANIA Hall and Whitfield, 1875
SCHIZOCRANIA FILOSA (Halli)
Plate 10, F, figures 20, 21

Orbicula ? filosa Hatt, Pal. New York, vol. 1, p. 99, pl. 30, fig. 9, 1847.
Schizocrania filosa Hall, BAsster, U. S. Nat. Mus. Bull. 92, p. 1144, 1915.—FoersTE, Bull.
Sci. Lab., Denison Univ., vol. 19, No. 3, p. 202, 1920.

This is a rare species in rocks older than the Trenton limestone, but it is re-
ported as common by Foerste in the upper to feet of the Plattin group (Macy
formation) or Barnhart formation of Ralls County, Mo., at several localities. One
of Foerste’s specimens is figured which shows a number of individuals of different
size attached to a pedicle valve of Rafinesquina cf. R. elongata. This early oc-
currence of Schizocrania and Rafinesquina ss. leads to the suspicion that the
top of the Plattin here is post-Black River in age and belongs to the Barnhart
formation.

Figured specimen.—to0g711.

Family DISCINIDAE Gray, 1840
Discinacea having a pedicle notch in early stages which is closed posteriorly
by later growth to leave a more or less long slit partially closed by a listrium.
Subfamily OrBICULOIDEINAE Schuchert, 1929

Foramen encased in a long pedicle tube.

Genus ORBICULOIDEA D’Orbigny, 1847
Orbiculoidea pD’OrBIGNY, Compt. Rend. Acad. Sci. Paris, vol. 25, p. 260, 1847.

ORBICULOIDEA EXIMIA Cooper, new species

Plate 13, C, figure 5; plate 20, D, figures 11-23
Shell fairly large, nearly circular in outline, biconical. Color shiny brown but
often with a blue-gray tarnish. Pedicle valve forming a low cone with a sharp,

nearly central apex directed slightly anteriorly. Slope anterior from the apex
gently concave; posterior slope also gently concave but somewhat less steep than

276 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the anterior slope. Lateral slopes concave, moderately steep. Foramen located
about 3 mm. posterior to the apex. Slit formed by migration of foramen, about
3 mm. long, narrow, but widening slightly near the foramen.

Brachial valve forming a depressed cone but with the center or apex located
about one-third the valve length from the posterior margin. Apex small, nearly
smooth and bluntly rounded. All slopes to the margins gentle.

Surface of both valves marked by concentric undulations which are more ele-
vated and regular on the pedicle valve and more gently rounded, lower and
crowded on the brachial valve and near the margins.

Measurements in mm.—Holotype, length 18.0, width 17.0, height 5.5.

Types.—Holotype: 109632f; figured paratypes: 109428a,b, 109632a,b,d,e,
109634b, 117953a; unfigured paratypes: 109632c, 109633a-e, 109634a,c-f,
117953b-j.

Horizon and locality—Bromide formation (Pooleville member-O-roplecia
gouldi zone) in Oklahoma: Rock Crossing of Hickory Creek, about center sec.
35, 1.5 S.; R.1 E., Criner Hills, Carter County.

Discussion.—This species is characterized by the biconical form and the nearly
central position of the beak of the brachial valve. In this latter respect it differs
strongly from all species of Schizotreta. Only one other species of Orbiculoidea
was found in the formations represented in this monograph. It is not comparable
to O. lamellosa (Hall) from the Trenton limestone, which is a much smaller
species.

ORBICULOIDEA LINVILLENSIS Cooper, new species
Plate 20, B, figures 4, 5

Small, longitudinally broadly elliptical in outline with the length slightly
greater than the width. Sides slightly flattened, anterior and posterior rounded.
Surface marked by fine concentric lines as usual in the genus.

Pedicle valve with apex located at center; anterior and posterior slopes mod-
erately convex, the posterior slope the steeper of the two. Lateral slopes flattened,
moderately steep. Pedicle groove long and slender, not quite 2 mm. in length.
Apex erect.

Brachial valve in the form of an irregular cone, the apex located one-third the
length from the posterior margin. Anterior slope steep and deeply concave ; pos-
terior slope steep but nearly flat in profile. Lateral slopes flat but steep. Two
muscle scars indistinctly visible anterolateral of the apex, and from these scars
2 pallial trunks extend, swing together for the length of about I mm., then diverge
slightly and extend nearly to the front margin.

Measurements in mm.—Holotype, pedicle valve: length 9, width 8.2, apex 4.4
anterior to posterior margin. Paratype, brachial valve (109637b): length 8.3,
width 7.4, apex located 2.7 mm. anterior to the posterior margin.

Types.—Holotype: 109637a; paratype: 109637b.

Horizon and locality—Oranda formation in Virginia: 0.6 mile northwest of
Linville Station, Broadway (15’) Quadrangle.

Discussion.—This species is characterized by the central position of the pedicle

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 277

apex, the slender pedicle groove and the posterior position of the apex in the
brachial valve. This is a combination of characters not seen in any of the other
species in the Appalachians.

Genus SCHIZOTRETA Kutorga, 1848

Schizotreta Kutorca, Verhandl. Russ.-Kais. Min. Ges. St. Petersburg for 1847, pp. 260, 272,
pl. 7, fig. 6, 1848.—H att and Crarke, Pal. New York, vol. 8, pt. 1, p. 135, 1892.—Girry,
Journ. Washington Acad. Sci., vol. 18, No. 5, pp. 128-142, 1928.

Acrosaccus WIitLarD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 258, 1928.

The name Schizotreta is applied to brachiopods having a subconical pedicle
valve and a brachial valve that is nearly flat or even somewhat concave. Kutorga’s
type species, Orbicula elliptica, is a small shell having a nearly flat brachial valve.
Furthermore, the brachial valve has the beak situated in a position distinctly
posterior to the middle. The beak is not marginal, but in the type species and
in all the American specimens here referred to this genus the beak is located
in a submarginal position, often less than a millimeter anterior to the margin.

Specimens of Dr. Willard’s genus Acrosaccus have the same characters as
those of Schizotreta. Willard’s genus was created for shells supposed to be re-
lated to Acrothele but without or rarely with a false cardinal area in the pedicle
valve and with the brachial protegulum near the posterior margin. Although
the type specimens do not show the pedicle opening it is stated that the presence
of a “pedicle tube proved the relationship to the Acrotretacea rather than the
Discinacea.” Actually the pedicle aperture in the numerous specimens now
available is quite discinoid, and Acrosaccus proves to be a synonym of Schizotreta.

SCHIZOTRETA CANADENSIS Wilson
Schizotreta canadensis Witson, Geol. Surv. Canada, Bull. 8, p. 25, pl. 2, figs. 14, 15, 1946.

Types.—Holotype: G.S.C. 6373; paratype: G.S.C. 6373a.
Horizon and locality—Leray-Chaumont formation, in Ontario, Canada: Lot
2, Concession IV, Cumberland Township.

SCHIZOTRETA CORRUGATA Cooper, new species
Plate 21, C, figures 7-20; plate 28, G, figures 24-28

Shell of about medium size for the genus, longer than wide, depressed conical
in profile and marked on the exterior by strong, elevated concentric ridges.

Pedicle valve forming a depressed, asymmetrical cone; posterior slope steep,
short, flat in profile; anterior slope nearly 3 times the length of the posterior
slope, almost flat or slightly concave in lateral profile; apical angle greater than
a right angle. Lateral slopes flat and fairly steep. Pedicle groove about 1.5 mm.
long, moderately wide; foramen generally small.

Brachial valve roundly elliptical in outline, the length being slightly greater
than the width; beak small, smooth, located 4 mm. or less from the posterior
margin ; posterior slope steep; anterior slope very gently convex; anterior pro-
file gently convex. Ornamentation variable, often extreme; ridges variable in

278 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

elevation and distance, occasionally fairly regular, more often slightly wavy;
ridges occasionally attaining 4 mm. or more in height.

Pedicle interior: Foramen entering valve near the posterior margin; slit form-
ing a low ridge on inside anterior to foramen and extending into umbonal cavity.
Muscles not visible in material at hand.

Brachial interior with posterior margin thickened and incurved ; inner surface
of posterior margin with a crescent-shaped mark convex inward. Lateral and
anterior margins flat. Center of valve occupied by 2 large muscle scars, oval in
outline and with their small ends directed posterolaterally. Anterior occupied
by 2 narrowly diverging thin pallial trunks.

Growth—yYoung specimens definitely oval in outline and marked by fine,
somewhat distant elevated ridges. Posterior slope lengthened only slightly.

Measurements in mm.—

Length Width Thickness
Paratype (pedicle valve 116808a) ........... 6.5 5.6 ?
2 (brachial valve 117972b) .......... 10.0 9.0 0.75?

Types—Holotype: 116808-1; figured paratypes: 116808a,c-e,g-k ; 117972a,b ;
unfigured paratypes: 116808b,f, 117972c-e.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—The ornamentation with its highly elevated ridges is distinctive
in this species and unlike any other known. The development of the ornamenta-
tion is interesting. On the anterior slope, continuous ridges alternate with short
ridges apparently formed at the front of the valve. These short ridges die out
on the flanks.

SCHIZOTRETA MICROTHYRIS Cooper, new species
Plate 20, A, figures 1-3; plate 22, D, figures 6-9; plate 22, I, figure 16; plate 27, A, figures 1-3

Shell large, nearly circular in outline, the length slightly greater than the width.
Pedicle valve in lateral profile forms a low cone with long concave anterior slope
and shorter, steeper, but flat posterior slope. Apex located somewhat less than
one-third the length from the posterior margin. Beak small and erect. Pedicle
groove short, narrowly elliptical and measuring slightly less than 2 mm. in length.
Lateral slopes steep, very gently concave.

Brachial valve forming an irregular low cone with the apex located about one-
fourth the length anterior to the posterior margin. Apex low and rounded, an-
terior slope nearly flat or gently concave; posterior slope short, concave, and
steep.

Surface of both valves marked by crowded, fairly regular elevated concentric
lines.

Measurements in mm.—The holotype, a pedicle valve, measures 21.7 in length,
19.5 in width; the posterior slope is 8 long but the apex is 6 in a straight line
anterior to the posterior margin. A small brachial valve (paratype 97547a) is
12.5 long by 11.5 wide, the apex is 3 anterior to the posterior margin in a straight

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 279

line; another brachial valve (paratype 116804a) is 19.7 long, 20.0 wide; the
apex is 3 anterior to the posterior margin.

Types—Holotype: 109640; figured paratypes: 97547a-c, 116803a, 1168042;
unfigured paratype: 116803b.

Horizon and locality—Oranda formation in Virginia: Along the railroad 4
to 4 mile east of Strasburg Junction; on U. S. Highway 11, 1 and 2 miles south-
west of Strasburg; Virginia Highway 55, 0.4 mile west of U. S. Highway 11 on
the north edge of Strasburg, Strasburg (15’) Quadrangle. 4 mile below the
dam on the Shenandoah River, 1 to 14 miles north of Edinburg, Edinburg (15’)
Quadrangle.

Oranda formation in Pennsylvania: 1 mile northwest of Guilford Springs,
Chambersburg (15’) Quadrangle.

Discussion.—This species is characterized by its large size and the short, ellip-
tical pedicle groove of the pedicle valve. It is unlike any other species yet known
in the Appalachian Valley, differing from S. subconica in larger size and circular
outline.

Some specimens show obscure details of the interior, but the valves are usually
so badly exfoliated that considerable uncertainty attends their interpretation.
Two specimens show the position of the pedicle groove on the interior but its
shape is not determinable.

SCHIZOTRETA PANNEA (Willard)
Acrosaccus panneus WitvLarD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 250,
pi 3. HE..3, 1028.

This is a large species based on a single pedicle valve which is distinguished
from S. shulert (Willard) by its much wider apical angle. A single specimen
(109657) in the National Museum collections is referred somewhat doubtfully to
this species.

Type.—Holotype: M.C.Z. 8592.

Horizon and locality.—Effna formation in Virginia: McNutt Quarry, 12 miles
southwest of Bland, near Sharon Springs, Burkes Garden (15’) Quadrangle.

SCHIZOTRETA PAPILLIFORMIS Ruedemann
Schizotreta papilliformis RUEDEMANN, New York State Mus., Bull. 42, p. 570, pl. 1, figs. 3-5,
1901.

Horizon and locality—Normanskill formation in New York: At Mount
Merino, near Hudson.

SCHIZOTRETA POSTEROCONVEXA Cooper, new species
Plate 28, B, figures 5, 6
Specimen represented by two pedicle valves only ; subcircular to slightly longi-

tudinally elliptical in outline; conical in profile with the apex located at about
the center. Posterior slope long and fairly strongly convex; anterior slope long,

280 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

deeply concave just anterior to the beak but the concavity flattening anteriorly.
Greatest convexity of posterior slope located in vicinity of pedicle groove and
foramen or for a distance of about 2 mm. Sides straight and steep, forming
an angle of 95°. Pedicle slit about 1.5 mm. in length, narrow and confined to
the convex area posterior to the beak. Surface marked by fine, elevated, evenly
spaced ridges, about 8 to the millimeter at the front margin.

Measurements in mm.—Holotype, length 9.7, width 8.0+, thickness 3.9.

Types.—Holotype: 116801b; paratype: 116801a.

Horizon and locality—Base of Athens formation (beds with Christiania) in
Tennessee: 0.2 mile southeast of Britton Church, 24 miles northeast of Calhoun,
Calhoun (T.V.A. 125-SW) Quadrangle.

Discussion.—This species is characterized by the strongly convex postumbonal
region and posterior slope and the deeply concave umbonal region. In these
respects it differs from S. shuleri which it strongly resembles.

SCHIZOTRETA SHULERI (Willard)
Plate 19, B, figures 7-9; plate 21, D, figures 21, 22

Acrosaccus shuleri Wiiarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 259,
pl. 3, figs. 1, 2, 1928.

Shell of about medium size for the genus; exterior marked by strong, even,
elevated, concentric ridges increasing in size gradually on the margins; about 5
ridges to the millimeter. Marginal ridges thickest on posterolateral edges.

Pedicle valve forming a moderately high, asymmetrical cone with the apex
located posterior to the middle. Posterior slope in lateral profile shorter than
the anterior slope and steep; anterior slope less steep than the posterior one but
considerably longer and very faintly convex; apical angle about 90°. Foramen
not preserved, but indications point to its position just posterior to the apex;
pedicle tube about 2 mm. long or slightly longer.

Brachial valve almost circular and nearly flat; convex in the umbonal region
but flattening anteriorly ; beak smooth, small, located about 0.5 mm. anterior to
the posterior margin.

Measurements in mm.—Pedicle valve (hypotype 109699a) : length 9.7, width
9.5, thickness 3.9, posterior slope 5.0, anterior slope 8.0, lateral slopes 5.5;
brachial valve (hypotype 109699c) : length 8.8, width 8.0.

Types.—Lectotype: M.C.Z. 8581 (brachial valve) ; paratype: M.C.Z. 8591
(pedicle valve) ; figured hypotypes: 109699a,c, 117969a,b.

Horizon and locality.—Effna formation in Virginia: At McNutt Quarry, 12
miles southwest of Bland, Burkes Garden (15’) Quadrangle.

Rich Valley formation in Virginia: Porterfield Quarry, 5 miles east of Salt-
ville, Maccrady (T.V.A. 218-NW) Quadrangle.

Botetourt formation in Virginia: On the south side of the road, 0.2 mile east
of Strasburg Junction, Strasburg (15’) Quadrangle.

Discussion.—This species was based on two poorly preserved specimens which
were thought to have relationships with Conotreta and its allies. The pedicle

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 281

valve preserves its shape fairly well, but details of the pedicle opening and slit are
absent. The brachial valve which is here selected as lectotype shows the outline,
profile, and details of the ornamentation. Schizotreta shuleri is similar to S.
posteroconvexa but does not have as strongly a convex posterior slope. The
species is also suggestive of S. corrugata but is not so coarsely ornamented.

SCHIZOTRETA SUBCONICA Cooper, new species
Plate 20, C, figures 6-10; plate 21, E, figures 23-32

Shell of medium size for the genus, longitudinally elliptical in outline; surface
marked by fine, even slightly elevated concentric lines.

Pedicle valve forming an eccentric cone with the apex about one-sixth the
length anterior to the posterior margin. Posterior slope flat, short and steep,
slightly less than 2 mm. long in the holotype ; anterior slope long and flat, measur-
ing about 5 mm. in the holotype. Lateral slopes steep, forming an angle of about
115°. Pedicle slit small, about 1 mm. long, narrow; foramen small.

Brachial valve longer than wide, gently convex in lateral profile, with the
greatest convexity in the umbonal region; beak submarginal, smooth; lateral
slopes gentle.

Measurements in mm.—

Length Width Thickness
Eloletype: beeetients.. O72). 0 leoargaiabeartee, 6.2 5.6 ?
Paratype (pedicle valve 109646b) ............. 7.8 Th 0.90
‘i mee Ms (EOOGAGA): cra. abaisinins ole 6.8 6.3 1.5
He (brachial valve 1096461) |... 02505 0s 8.6 7.6 aS

Types.—Holotype: 116805a; figured paratypes: 109646b,d,e,f,g, 116805b-e ;
unfigured paratypes: 109646a,c,h-j.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species is characterized by its fairly high conical profile,
elliptical form, and the fine, uniformly even character of the ornamentation. In
the latter respect it suggests S. posteroconvexa but differs in having a flat pos-
terior slope and smaller pedicle slit. This species is more finely ornamented than
S. shuleri and is quite unlike S. willardi in profile, outline, and ornamentation.

SCHIZOTRETA WILLARDI Cooper, new species
Plate 11, C, figure 5; plate 19, A, figures 1-6; plate 21, F, figures 33-41

Shell fairly large for the genus, depressed conical in profile, circular in outline ;
brachial valve gently concave ; surface marked by fairly even, elevated concentric
lines, often crowded in the posterolateral region.

Pedicle valve with the apex slightly posterior to the center; posterior slope
long and gently convex; anterior slope long and gently concave, the greatest
concavity located at the umbo just anterior to the beak; lateral slopes long and
gently concave. Pedicle slit short and fairly wide, tear-shaped in outline with
the acute apex anterior in position; floor of slit marked by a deep groove; fora-

282 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

men small and posterior margin of slit overhanging the opening. Inside the
pedicle valve the foramen enters the shell about 1.5 mm. from the posterior mar-
gin and forms a tube that makes a ridge anterior to the umbonal chamber. A
short ridge occurs anterior to the pedicle tube and in the umbonal chamber
divides 2 muscle impressions.

Brachial valve gently convex in the umbonal region but flattened to concave
anteriorly ; posterior slope short, about I mm. in length in an adult shell, slightly
concave and extended in about the same plane as the anterior part of the shell.
Beak small, smooth and with a finely ornamented umbo; anterior slope convex
and somewhat swollen in the posterior portion but becoming gently concave
anteriorly ; posterolateral region reflected in a brachial direction and thus pro-
ducing concave lateral slopes. Details of the interior not preserved.

Measurements in mm.—

Length Width Thickness
Paratype (pedicle valve 109697c)............ 7.0 7.5 1.0?
ot (brachial valve 109697e) .......... 11.0 12.0 ?

Types.—Holotype: 109697b; figured paratypes: 109660a, 109697c,e-g,
116806a-c,e,f,g ; unfigured paratypes: 109697a,d, 116806d,h,i.

Horizon and locality.—FPratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This species is characterized by its depressed form, short and
tear-shaped pedicle slit, and the anterior concavity of the brachial valve. In
these respects it is quite unlike any of the species herein described.

SCHIZOTRETA sp. 1
Plate 19, G, figure 22

This is a small species slightly more than 6 mm. in diameter and forming a
high, irregular cone. The anterior and posterior slopes are nearly equal, but
the latter is slightly shorter and steeper. The apex is bluntly rounded. The
pedicle groove is long. The surface is marked by fine, even concentric lines.

Figured specimen.—109650.

Horizon and locality—Hogskin member of the Lincolnshire formation (upper
30 feet) in Tennessee: 44 miles west-southwest of Thorn Hill, Avondale (T.V.A.
162-SW) Quadrangle.

Superfamily CRANIACEA Waagen, 1885
Family CRANIIDAE Gray, 1840

Usually calcareous shells cemented by the pedicle valve and with more or less
conical brachial valve.

EOCONULUS Cooper, new genus

(Greek eos, early; conus, cone)

Minute to small, misshapen cones with the apex on the posterior side; pos-
terior margin nearly straight ; interior of brachial valve with a large, oval muscle

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 283

scar located in the posterolateral extremities. Shell substance impunctate,
corneous.

Genotype—Eoconulus rectangulatus Cooper, new species.

Discussion.—This peculiar little shell occurs in abundance in the residues from
the acetic acid etching of the Pratt Ferry limestone. The specimens are usually
without an apex, which must have been easily exploded by the carbon dioxide
resulting from the etching. At present the pedicle valve, which was undoubtedly
attached, is not known. The genus occurs in the Pratt Ferry limestone and in
the basal beds of the Botetourt formation in Virginia.

This genus differs from Petrocrania in its impunctate and “chitinophosphatic”’
shell and the simplicity of its interior. It is undoubtedly an early form of the
Craniidae but occurs with undescribed normal examples of Petrocania.

EOCONULUS RECTANGULATUS Cooper, new species
Plate 10, B, figures 11-13
Shell small to minute with the posterior margin nearly straight and slightly
wider than the anterior margin; sides nearly straight to strongly rounded ; antero-

lateral and posterolateral extremities narrowly rounded. Anterior and posterior
slopes subequally steep ; apex slightly eccentric.

Measurements in mm.—

Length Width Height
SUMTER RS aoc Biotest spa ote cucaneaeetaee I.I 1.4 0.5
Paratype CLIOGSAOD) ites sccissue cis tielere etn elelsre ctor i 1.6 0.9
ns (CHTIOSAGENE!. 8% eee eee cincboue eens 2 1.4 0.8
d (@rb84od) eee as. JS Baa see 1.4 2.0 1.2
rs (iGSAGe): GHIssiss: ¢sch skies Dheao ae 1.4 2.1 0.8

Types.—Holotype : 1168402 ; figured paratype: 116840b; unfigured paratypes:
116840c-e.

Horizon and locality.—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—Another species occurs in the Botetourt limestone of Virginia on
the south side of the road 0.2 mile east of Strasburg Junction. This is a large
species differently shaped from E. rectangulatus, but the specimens are not good
enough for description. The members of this genus are readily distinguished
from the usual members of the Craniidae by their shell substance.

Genus ACANTHOCRANIA Williams, 1943
Acanthocrania Witi1AMs (J. Steele), U. S. Geol. Surv. Prof. Pap. 203, p. 71, 1943.

This name was proposed to include Cranias “ornamented by fine papillae or
fine spines.” Williams designated Crania spiculata Rowley as the type of the
genus.

This genus is widely distributed and is fairly abundant in the Ordovician. It
also occurs in the higher rocks. At present the pedicle valve of the genus is not

284 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

known; it may have been very thin like Philhedrella and therefore not well
preserved.

The name Choniopora may preoccupy the present one as already pointed out
by Williams, but until the interior of that genus is made known Williams’ ge-
neric name is preferred. Choniopora was originally thought to be a bryozoan
colony but was later shown by Geinitz to have the shell structure of the Craniidae;
the internal musculature still remains unknown.

ACANTHOCRANIA CUMBERLANDENSIS (Foerste)
Plate 26, D, figures 9-11

Crania granulosa cumberlandensis Forrste, Bull. Sci. Lab., Denison Univ., vol. 16, p. 41,
pl. 5, fig. 8, r9ro.

Types.—Lectotype: 87157a; paratypes: 87157b (c, Foerste, 1910).
Horizon and locality—Wells formation in Tennessee: 14 miles southwest of
Cumberland City, in Stewart County.

ACANTHOCRANIA ERECTA Cooper, new species
Plate 26, G, figures 16, 17

Shell known only from brachial valve, of about medium size for the genus,
nearly circular in outline, subconical in profile and with a nearly central apex.
Sides flat in profile, moderately steep. Surface covered by short, blunt spines.

Measurement in mm.—Holotype, length 9, width 9.5, height 4.

Type.—Holotype: 109789.

Horizon and locality—Bromide formation (Mountain Lake member?) in
Oklahoma: NW43 sec. 27, T. 1 S., R. 2 E., midway between Dougherty and
Davis.

Discussion.—This species can be distinguished readily from A. granulosa and
A. setigera by its nearly symmetrically conical form and profile and by the
greater height of the cone. The single specimen representing this species is also
marked by low ridges, produced by the uneven surface of the host, which ex-
tend from the posterior side to the anterior side.

ACANTHOCRANIA GRANDIS Cooper, new species
Plate 26, A, figures 1-3

Species known from brachial valve only; large for the genus, crudely trans-
versely elliptical in outline; conical in both profiles; later profile unsymmetri-
cally conical, the anterior slope long and gently convex; posterior slope short,
steep, and concave; apex located about one-fifth the length from the posterior
margin ; break smooth and slightly curved. Anterior profile a symmetrical cone
with straight and steep sides. Surface covered by spines about 1.25 mm. in length.

Measurements in mm.—Holotype, length 15.2, width 17.4, height 6.6.

Type.—Holotype: 116838.

Horizon and locality—Base of Benbolt formation in Virginia: On the west

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 285

slope of the hill 4 mile east of Cedar Point School, Hilton (T.V.A. 197-NW)
Quadrangle.

Discussion—This species is characterized by its large size, unsymmetrical
form in lateral view, and densely matted spines. In these respects it differs from
all other species described herein.

ACANTHOCRANIA GRANULOSA (N. H. Winchell)

Crania granulosa N. H. WincuHELL, 8th Ann. Rep. Geol. Nat. Hist. Surv. Minnesota, p. 63,
1880.—SARDESON, Minnesota Acad. Nat. Sci., Bull. 3, p. 343, 1892—-WINCHELL and
ScuucHERrt, Geol. Minnesota, vol. 3, p. 373, pl. 29, figs. 34, 35, 1893.

Horizon and locality——Decorah formation, Minneapolis, Minn.

ACANTHOCRANIA OKLAHOMENSIS Cooper, new species
Plate 27,H, figures 18-20

Shell fairly large for the genus, subcircular in outline, conical in both profiles ;
apex very slightly posterior to the center; lateral profile with steep, nearly flat
anterior slope; posterior slope steeper than the preceding, fairly deeply concave
just posterior to the beak but nearly flat posteriorly. Anterior profile with flat
and only moderately steep slopes. Surface marked by very fine spines.

Measurements in mm.—Holotype, length 9.7, width 10.2, height 3.7.

Types—Holotype ; 1168374; figured paratypes: 116837b-d.

Horizon and locality—Bromide formation (Pooleville member—bed 2) in
Oklahoma: West of Nebo store in sec. 22, T. 2 S., R. 3 E., Murray County.

Discussion.—This species is unlike A. subquadrata from the Bromide forma-
tion in having a more symmetrical cone and in lacking the well-marked, triangu-
lar posterior slope. It also appears to be a larger shell.

ACANTHOCRANIA SETIGERA (Hall)
Plate 25, A, figures 1-5

Crania setigera HAtt, Descr. new species Crinoidea and other fossils, p. 12, 1866; 24th Rep.
New York State Cab. Nat. Hist., p. 220, pl. 7, fig. 15, 1872-—-Hatt and CLarkKE, Pal.
New York, vol. 8, pt. 1, pl. 4, H, figs. 14-16, 1892—WINCHELL and ScHuCcHERT, Geol.
Minnesota, vol. 3, p. 372, pl. 20, figs. 32, 33, 1893.—GraBau and Suime_r, N. Amer. index
fossils, vol. 1, p. 207, figs. 241e-f, 1907.

Figured specimens.—24739, 247438.

Horizon and locality.—Platteville and Decorah formations, Wisconsin and
Minnesota.

ACANTHOCRANIA SPINOSA Cooper, new species
Plate 26, H, figures 18, 19

Shell small for the genus, irregular in form, but crudely circular in outline.
Greatest height at the middle. Apex smooth, small, located above the posterior
margin and behind the middle of the valve, depressed below the highest point.
Posterior slope short and steep. Surface covered by spines, which are about
4mm. in length near the margin.

286 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—Holotype, length 4, width 5, height 2.

Types.—Holotype: 109795; paratype: 1097096.

Horizon and locality.—Edinburg formation (Liberty Hall facies) in Virginia:
1.8 miles S. 4° W. of Bethel Church, 5.9 miles east of Harrisonburg, Harrison-
burg (15’) Quadrangle ; Effna formation: Lower part McNutt Quarry, 12 miles
southwest of Bland, Burkes Garden (15’) Quadrangle.

Discussion.—One specimen of this species is a silicified brachial valve show-
ing the spines well. The species can be recognized and differentiated from other
known species by the peculiar profile in which the greatest height of the valve is
at the middle with the apex posterior, approximately marginal and depressed
below the highest point.

ACANTHOCRANIA SUBQUADRATA Cooper, new species
Plate 26,1, figures 20-25; plate 27, B, figures 4-7

Shell small, conical in profile, subquadrate in outline. Apex about one-third
the length anterior to the posterior margin. Lateral and anterior margins broadly
rounded ; posterior margin nearly straight. Lateral profile with strongly convex
anterior slope and slightly concave and steep posterior slope. Surface marked
by very fine spines. Interior with large posterior muscle scars elongate-elliptical
in outline. Central scars smaller and more circular. Pedicle valve unknown.

Measurements in mm.—The holotype (109759b) is 9.7 long, 8.8. wide, and
2.7 high. The apex is located 3.7 anterior to the posterior margin.

Types.—Holotype: 109759b; figured paratypes: 109759¢,d, 109793, 116836;
unfigured paratypes: 1097592, e.

Horizon and locality—Bromide formation (upper Mountain Lake member) in
Oklahoma: On Oklahoma Highway 18, 1.8 miles south of Sulphur, Murray
County. Bromide formation (Pooleville member—Lonchodomas zone) in Okla-
homa: Rock Crossing of Hickory Creek, about center sec. 35, T. 5 S., R. 1 E,
Criner Hills, Carter County.

Discussion.—This species differs from A. setigera in its smaller size, much
finer spines, and subquadrate form. It differs from A. erecta in its lower valve
and finer spines.

ACANTHOCRANIA sp. t

Plate 27, F, figures 12-14

Shell forming a low cone with apex slightly posterior to the middle; lateral
profile with moderately long, convex anterior slope; posterior slope shorter,
steeper, and nearly flat except for a short concave area just posterior to the beak ;
anterior profile with nearly flat, moderately steep slopes. Surface marked by very
fine spines.

Measurements in mm.—116839, length 13.0, width 13.2, height 4.8.

Figured specimen.—1 16839.

Horizon and locality—Lebanon formation (Doleroides zone) in Tennessee:
On U. S. Highway 70N opposite Fairview Service Station, 4 mile west of Rome,
Smith County.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 287

Discussion—This species is characterized by its circular form, nearly sym-
metrical conical profiles, and very fine spines.

Genus PETROCRANIA Raymond, 1911

Petrocrania RaymMonp, Ann. Carnegie Mus., vol. 7, No. 2, p. 229, I9QII.

This genus is of rare occurrence in early Middle Ordovician rocks except lo-
cally, where it may be common. As far as known no member of this genus has
yet been taken from high Pogonip or early Chazyan rocks. The oldest species,
therefore, is Petrocrania prona (Raymond) from the Crown Point limestone of
New York.

A point of considerable interest in connection with species of Petrocrania
found in the rocks under consideration is the fact that at least as far as the Na-
tional Museum collections are concerned no pedicle valves have yet appeared. In
discussing P. ulrichi, Winchell and Schuchert (1895, p. 375) remark on this fact
but suggest that the pedicle vaive was convex. This suggestion was supported
by the statement that the two valves figured by Hall and Clarke appeared to
have different musculature and indicated pedicle and brachial valves. The muscu-
lature as restored for the pedicle valve is not usual for the genus, and it is prob-
able that the restoration and identification of the valve are in error.

PETROCRANIA CICATRICULA Willard

Petrocrania cicatricula Wittarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 260, pl. 3, fig. 4, 1928.

Type.—Holotype: M.C.Z. 8590.
Horizon and locality —“Ottosee” (probably Hogskin) : Quarry north of Lut-
trell, Tenn.

PETROCRANIA DIXONENSIS Cooper, new species

Plate 27, E, figures 10, I1

Under this heading is placed a single species of fairly large size from the
Platteville limestone. It has the following characters: Elliptical in outline with
the width about 14 times the length, posterior margin short and flat; lateral and
anterior margins broadly rounded; beak almost marginal ; posterior slope steep,
and slightly concave; anterior slope long, strongly convex; anterior profile
broadly convex. Distance of beak from posterior margin 1.5 mm.

Measurements in mm.—Holotype, length 13.6, width 16.5, thickness 3.

Type.—Holotype: 45215.

Horizon and locality—Platteville formation in Illinois: At Dixon, Dixon
(15’) Quadrangle.

Discussion—This species differs from P. trentonensis Hall in its large size,
the more marginal apex, and the strongly inflated and proportionately longer
anterior slope.

288 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PETROCRANIA HALLI (Sardeson)
Plate 25, D, figures 11, 12
Crania halli SarpEson, Minnesota Acad. Nat. Sci., Bull. 3, p. 328, pl. 4, figs. 8-10,
Apr. 9, 1892.

Craniella ulrichi HAtt and CriarKE, Pal. New York, vol. 8, pt. 1, p. 181, pl. 4,I, figs. 1, 2,
1893.

C. ? ulrichi Hall and Clarke, WINCHELL and ScHUCHERT, Geol. Minnesota, vol. 3, p. 375,
pl. 20, figs. 38, 30, 1893.

Specimens of P. halli labeled by Dr. Sardeson and deposited in the National
Museum have all the significant characters of P. ulrichi. The two species are
here regarded as synonyms, and the name P. halli has precedence. Much un-
certainty exists about the dates of some of the Minnesota species, but in this case
it seems clear that Sardeson’s name should supercede P. ulrichi. The letter of
transmittal of Pal. New. York, vol. 8, pt. 1, is dated May 1892, whereas Sarde-
son’s paper appeared in the early part of April. Winchell and Schuchert state
that it “. . . is well known, part 1 of that volume [Pal. New York, vol. 8] was
printed nearly two years before it was published.” As the validity of a species
depends on its date of publication, the fact mentioned by Winchell and Schuchert
has no bearing on the standing of the species.

Figured specimens.—24218a, 45218a.

Horizon and locality—Decorah formation (Spechts Ferry member—Sticto-
porella bed, to Ion member—Phylloporina bed) in Minnesota: St. Paul and
vicinity.

PETROCRANIA HAMILTONIAE (Hall)
Plate 25, E, figures 13, 14

Crania hamiltoniae HALL, 13th Rep. New York State Cab. Nat. Hist., pp. 76, 77, figs. 4, 5,
1860; Pal. New York, vol. 4, p. 27, pl. 3, figs. 17-23, 1867.

Impressions of the interior of this species are introduced to show the pallial
marks and musculature for comparison with Ordovician species.

Figured specimens.—116834b,c.

Horizon and locality—Basal Ludlowville (Stone Mill member) in New
York: At 1,265 feet elevation on the road 1 mile southwest of Randallsville,
Morrisville (15’) Quadrangle.

PETROCRANIA INFLATA Cooper, new species
Plate 25,1, figures 24, 25; plate 25, J, figures 26-35; plate 26, F, figures 14, 15

Small to medium size for the genus, forming a rounded ellipse in outline with
the width slightly greater than the length. Profile an irregular cone with the
apex pointing posteriorly and overhanging the posterior slope. Apex located
at about one-fourth the length from the posterior margin. Posterior slope steep
and slightly concave; anterior slope steep and strongly convex in profile. Sur-
face marked by concentric undulations, in some instances with irregular patterns
induced by the ornamentations of the host.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 289

Measurements in mm.—

Length Width Thickness
PRGA cdrs'e 5 cca e os evo. o siegsie a 3.0. « ergs ea 9.3 10.8 4.0
PatALy Pen LOO7O0d ) ose sc ce sc eleaee cceee wees 11.2 Ei7 4.7

Types.—Holotype: 109785a; figured paratypes: 109758, 109767, 109783¢,
109785e; unfigured paratypes: 109783a,b,d,e, 109785b-d, 109786a.

Horizon and locality—Bromide formation (Pooleville member—Oxopflecia
gouldi zone) in Oklahoma: Rock Crossing of Hickory Creek, about center sec.
35, 1.5 S., R. 1 E., Carter County, Criner Hills ; (183 feet below massive lime-
stone), second dam on Spring Creek, north of Woodford, Murray County.

Discussion.—This species is suggestive of P. trentonensis (Hall) but differs
in its strongly inflated anterior slope.

PETROCRANIA ? MAGNA Cooper, new species
Plate 25, B, figures 6, 7

Shell very large for the genus, represented by brachial valve only, irregularly
conical, broadly elliptical or crudely rectangular in outline, with the width about
one-third greater than the length. Posterior margin nearly straight, lateral mar-
gins gently rounded; anterior margin bilobed because of a slight emargination
near the middle. Strongly convex in profile, with the greatest height at about
the middle. Apex posterior in position and overhanging the short, steep posterior
slope. Anterior profile moderately convex. Sulcus, shallow, extending from a
point near the apex to the front margin where it forms a slight indentation. Sul-
cus located to the left of valve center when apex is held away from the observer.

Measurements in mm.—Holotype, length 20, width 26.5, height 7.

Types.—Holotype: 109762.

Horizon and locality —Effna formation in Virginia: Lower part of McNutt
Quarry, 12 miles southwest of Bland, Burkes Garden (15’) Quadrangle.

Discussion.—This species is not likely to be confused with any other known
Middle Ordovician craniid because of its large size and peculiar form. As one
of the earliest members of the genus, the great size is remarkable.

PETROCRANIA PRONA (Raymond)
Plate 25, F, figures 15-19

Crania prona Raymonp, Ann. Carnegie Mus., vol. 3, p. 594, 1906.

Petrocrania prona RayMonp, Ann. Carnegie Mus., vol. 7, No. 2, pl. 34, figs. 26-31, 1911.

Not P. prona Raymond, Witiarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 260, pl. 1, fig. 6, 1928.

The shells from the quarry north of Luttrell identified as this species are in-
correctly placed. It is a large species which cannot now be identified with any
known species, but the material is inadequate to describe as new.

Types.—Cotypes: Carnegie Mus. 5441-5443; figured hypotype: A.M.N.H.
25046
at

290 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality—Crown Point formation in New York: East side Val-
cour Island, Sloop Bay, and Chazy, Plattsburg (15’) Quadrangle.

Mingan formation (zone 5) on Bald or Mingan Island, Mingan Group,
St. Lawrence River, Quebec, Canada.

PETROCRANIA TRENTONENSIS (Hall)
Plate 27, G, figures 15-17

Crania trentonensis Hatt, Descr. new species Crinoidea and other fossils, p. 12, 1866; 24th
Rep. New York State Cab. Nat. Hist., p. 210, pl. 7, figs. 11, 12, 1872; Pal. New York,
vol. 8, pt. 1, pl. 4H, figs. 21, 22, 1893—WINCHELL and ScHucHERT, Geol. Minnesota,
vol. 3, p. 374, pl. 20, figs. 36, 37, 1803.

Type.—Hypotype: 116835.

Horizon and locality—Martinsburg formation (Salona equivalent) in Vir-
ginia: On Virginia Highway 617=910, 0.15 mile north of Green Mount Church,
4 to 5 miles north of Harrisonburg, Broadway (15’) Quadrangle.

PETROCRANIA sp. 1
Plate 22,G, figure 14; plate 25,H, figure 23

In the “Ottosee” facies near the base of the Lowville in the belt running along
the Cumberland Front and in the high Chickamauga limestone in northwestern
Georgia a small species of Petrocrania occurs on slabs in some abundance. Un-
fortunately, all the valves in the National Museum collection show the interior
only, thus making it unwise to describe the species. The form of the valves is
suggestive of P. trentonensis.

Figured specimens.—109776a, 109778.

Horizon and locality.—Ridley formation in Georgia: On U. S. Highway 27
just north of Chickamauga Creek, Kensington (T.V.A. 106-SE) Quadrangle.

Dryden formation in Tennessee: Lone Mountain-Tazewell road, 14 miles
northeast of Lone Mountain; road along Little Sycamore Creek, 4 mile north-
east of west edge of Howard Quarter (T.V.A. 162-NW) Quadrangle; west side
of the sharp loop on the road down Flint Creek, NW4 center subquad., Pow-
der Springs (T.V.A. 154-SW) Quadrangle.

PETROCRANIA ? sp. 2
Plate 25, C, figures 8-10

Species represented by a single brachial valve of small size; outline irregular ;
beak not discernible ; both profiles broadly convex; posterior side the narrower.
Interior with 2 large but indistinct muscle scars on the posterolateral extremities.
Anterior with a short and low septum.

Figured specimen.—109770.

Horizon and locality—Edinburg formation (base of the Liberty Hall facies)
in Virginia: 1.8 miles S. 4° W. of Bethel Church, 5.9 miles east of Harrisonburg,
Harrisonburg (15’) Quadrangle.

Discussion.—The specimen in question is a silicified valve in which the interior

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 291

details are not clearly shown. The valve is also indefinite in shape, and the apex
is not discernible. The large muscle scars in the rear of the shell are not clear
but strongly suggest Petrocrania. The unusual feature of the valve is the low
and short median septum. This may be a freak of silicification but seems to be
a part of the valve.

PETROCRANIA sp. 3
Plate 25, G, figures 20-22

This is a small species or possibly the young of a larger one. The outline is
somewhat trapezoidal. The largest specimen measures 7.2 mm. long, 7.7 mm.
at the widest part which is well anterior to the middle, and nearly 4 mm. high.
The apex is about three-fourths the length posterior to the front margin.

Figured specimens.—109766a,b.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: From a deep well on the Jones Farm, sec. 22, T. 5 N., R. 3 E., Potta-
watomie County.

Genus PHILHEDRA Koken, 1889
Philhedra Koxen, Neues Jahrb. Mineral., Geol. and Paleont., Beil., Bd. 6, p. 465, 18809.

PHILHEDRA DEPRESSA Cooper, new species
Plate 26, B, figures 4, 5

Shell of a brachial valve of about medium size for the genus, nearly circular
in outline and forming a low cone in lateral profile. Lateral margins gently
rounded but anterior margin more strongly rounded and posterior margin nearly
straight. Apex located two-fifths the length from the posterior margin. Beak
and umbo smooth; beak directed posteriorly. Anterior slope only moderately
steep and gently convex in profile. Posterior slope long and flattened just pos-
terior to the apex, moderately steep. Lateral slopes slightly convex. Surface
marked by distant strongly elevated costellae, 2 or 3 in the space of 1 mm. at the
front margin. The apex is located 4 mm. anterior to the posterior line.

Measurements in mm.—Holotype, length 10.2, width 10, thickness 2.2.

Type.—Holotype : 109749.

Horizon and locality—Prosser formation in Wisconsin: 25 feet above base of
the Duck Creek Quarry, near Green Bay.

Discussion.—This species is distinguished from Philhedra laelia by its more
nearly central beak and more distant costellae.

PHILHEDRA FERRUGINEA Cooper, new species
Plate 26, C, figures 6-8

Brachial valve circular in outline and forming a low cone with the apex
slightly posterior to the center. Anterior slope slightly convex and gentle; pos-
terior slope flat in profile, shorter and steeper than the anterior slope. Surface
marked by numerous fine costellae 4 or 5 in a millimeter at the periphery. Apex
located about 6 mm. anterior to the posterior margin.

292 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—Holotype, diameter 14, height 3.5.

Type.—Holotype: 109750.

Horizon and locality—Red Knobs formation in Tennessee: 7 miles north-
east of Charleston, Calhoun (T.V.A. 125-SW) Quadrangle.

Discussion.—This species is characterized by its large size, circular outline,
and its fairly high conical profile. Inasmuch as this is one of the earliest known
species of the genus, its generally advanced form is exceptional. The specimen
is as large as is commonly found in the Devonian, when species of this genus are
abundant. It is larger than other Ordovician species and can be distinguished
readily from Philhedra laclia and P. minor by this character as well as the very
fine costellae.

PHILHEDRA MINOR Cooper, new species

Plate 26, EF, figures 12, 13

Brachial valve small, slightly longer than wide, forming an eccentric cone.
Apex smooth, located about one-fifth the length from the posterior margin, and
overhanging the posterior slope. Anterior slope flattened, slightly inclined for
half its length, but moderately steep and convex in its anterior half. Posterior
margin nearly straight. Posterior slope steep and concave. Costellae nearly
reaching the beak, increasing by implantation, threadlike and crowded at the front
margin.

Measurements in mm.—Holotype, length 6.6, width 4.2, height 2.

Type.—Holotype: 109760.

Horizon and locality.—Pierce formation in Tennessee: Pierce Mill, Walter-
hill, 74 miles north of Murfreesboro.

Discussion—This species suggests Philhedra laelia (Hall) but differs in its
more elevated form and much finer ornamentation. It is a more elevated cone
and with finer ornamentation than P. depressa.

PHILHEDRA ? sp. 1
Plate 22, H, figure 15
This is the interior impression of a small species showing the characteristic
pair of large muscles near the apex of the brachial valve. The specimen is 10.8
mm. long and 8.7 mm. wide. Details of the exterior are unknown.
Figured specimen.—109761.
Horizon and locality.—Bromide formation (Mountain Lake member) in Okla-
homa: Near the northeast corner NW} sec. 27, T. 1 S., R. 2 E., 3 miles north-
west of Dougherty, Murray County.

Subclass PYGOCAULIA
Suborder ORTHOIDEA Schuchert and Cooper, 1932
Superfamily OrTHACEA Walcott and Schuchert, 1908
Family ORTHIDAE Woodward, 1852

Progressive and terminal Orthacea with interareas on both valves; delthyrium
open in most genera; pseudodeltidium rare ; muscle field of pedicle valve oval or

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 293

obcordate ; ovarian impressions subreniform ; vascula media subparallel. Brachial
valve with simple cardinal process, rodlike brachiophores, divergent and without
other support than the shell substance of the notothyrial platform ; chilidial plates
or chilidium rare.

Subfamily OrtTHINAE Schuchert and Cooper, 1931

Progressive Orthidae having short and curved interareas in the pedicle valve.

Genus ARCHAEORTHIS Schuchert and Cooper, 1931
Archaeorthis ScHUCHERT and Cooper, Amer, Journ. Sci., vol. 22, p. 243, 1931; Mem. Peabody
Mus. Nat. Hist., vol. 4, pt. 1, p. 80, 1932—ULricu and Cooper, Geol. Soc. Amer. Special
Pap. 13, p. OI, 1938.

ARCHAEORTHIS BICONVEXA Cooper, new species
Plate 31, B, figures 7-I0

Shell of about usual size for the genus, wider than long; sides and anterior
margin moderately rounded; hinge narrower than the midwidth which is the
widest part; surface marked by strong, elevated, narrowly rounded costellae
which increase by implantation and number 2 or 3 in a millimeter at the front
margin. Costellae subfasciculate at the front margin.

Pedicle valve strongly convex in lateral profile and with the maximum curva-
ture on the umbo; anterior profile narrowly domed but with sides moderately
sloping. Beak strongly incurved; umbo rounded and swollen; median region
swollen nearly to the anterior margin to form a poorly defined fold. Sides mod-
erately steep; anterior slope steep. Interior with large teeth having deep crural
fossettes. Lateral plates developed along the delthyrial margin. Delthyrial cavity
deep ; callosity anterior to muscle field short but extending to about the middle.

Brachial valve moderately convex in lateral profile and with the maximum
depth just posterior to the middle; anterior profile gently and broadly convex ;
umbonal and postmedian regions swollen ; lateral slopes moderately steep toward
the posterolateral extremities. Anterior slope gentle. Median sulcus poorly de-
fined throughout its length, shallow.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (pedicle valve) .......... 5.9 ? 7.4 5.8 2.0
Paratype (brachial valve 116852b).. ? 4.8 5.9 4.0 i:

Types.—Holotype: 116852a; figured paratype: 116852b.

Horizon and locality—Limestone lens in the Womble shale in Oklahoma:
1,100 feet south and 700 feet west of the NE. corner sec. 3, T. 2 N., R. 19 E.,
Pushmatahah County.

Discussion.—This species is featured by its deep pedicle valve and a brachial
valve with only a very shallow sulcus developed. In the latter respect it differs
from all the Canadian Archaeorthis described by Ulrich and Cooper which have
a well-marked brachial sulcus.

294 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genus ORTHAMBONITES Pander, 1830

Orthambonites PANveER, Beitr. Geogn. Russ. Reiches, p. 80, 1830.

This name has long been under the synonymy of Orthis but was lately revived
by Cooper (1942) for the biconvex orthids. The genus Orthis as restricted is a
concavo-convex shell having some similarities to Cyrtonotella. On the North
American continent a few species only conform to the generic definition of re-
stricted Orthis ; consequently, the need of a name for the host of biconvex forms
becomes apparent.

The species placed under Orthambonites in this monograph are actually a com-
posite lot. Some of them conform closely to the description of the genus, but
others obviously are more remotely connected to it. Many more species will have
to be described and considerable work performed on the internal characters of a
host of species now indifferently referred to Orthis before the true generic affini-
ties of Orthambonites and its derivatives will have been made known.

As used here the genus Orthambonites is for biconvex orthids having a costate
ornamentation and with orthoid cardinalia and the pedicle musculature of the
Orthidae. A few of the species referred here do not conform strictly to this type,
such as O. bifurcatus, O. brachiophorus with its unusually long brachiophores,
O. dinorthoides with its elongate pedicle muscle field, and O. subconvexus.

ORTHAMBONITES ACUTIPLICATUS (Raymond)
Plate 33, C, figures 8-11

Orthis acutiplicata RAYMOND, Amer. Journ. Sci., 4th ser., vol. 20, p. 370, 1905; Ann. Carnegie
Mus., vol. 7, No. 2, p. 237, pl. 35, figs. 8-10, 1911.

Types.—Lectotype: Carnegie Mus. 5458; paratypes: Carnegie Mus. 5459,
5460.

Horizon and locality—Day Point ? formation in New York: Southern end of
Valcour Island, Lake Champlain, Plattsburg (15’) Quadrangle.

ORTHAMBONITES ANGULATUS Cooper, new species
Plate 36, C, figures 19, 20

Shell large for the genus, known only from the pedicle valve ; wider than long ;
hinge forming the widest part ; cardinal extremities produced into small, acutely
angular ears ; sides gently rounded ; anterior margin fairly strongly rounded ; sur-
face costate, costae 17 in number, angular.

Pedicle valve moderately convex in lateral profile with the greatest convexity
in the median region ; anterior profile broadly convex, the median region some-
what narrowly rounded but the lateral slopes long and gentle; umbonal region
slightly swollen, the swelling continued to the anterior margin as a low but in-
distinct fold. Interarea moderately long, slightly curved, approximately ortho-
cline. Teeth small, delthyrial cavity deep; dental plates short ; umbonal cavities
mostly filled; muscle field with a short thickening anterior to its front margin;
diductor scars slender; adductor track wide.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 295

Measurements in mm.—Holotype, length 15.2, width 18.2, hinge width 21.4,
thickness 4.1.

Type.—Holotype: 109797.

Horizon and locality—Probably Arline formation in Tennessee: James Way-
land Farm near Riverdale, 9 miles east of Knoxville, Shooks Gap (T.V.A.
147-NE) Quadrangle.

Discussion.—This is a large species suggestive of O. buttsi but differs from
that species in its stronger costae and much larger size.

ORTHAMBONITES BELLUS Cooper, new species
Plate 35, D, figures 35-51

Shell small for the genus, slightly wider than long, hinge slightly narrower
than the greatest shell width which is at the middle. Cardinal extremities approxi-
mating a right angle. Lateral margins nearly straight ; anterior margin narrowly
rounded. Surface marked by narrowly rounded costellae separated by interspaces
slightly narrower than the costellae. Intercalated costae occur, but intercalation
takes place only in I generation on the umbo or in its vicinity ; 30 to 32 costae at
the anterior margin.

Pedicle valve with umbo and posteromedian portion swollen, beak prominent
and with part of the umbo protruding posterior to the posterior margin. Anterior
slope moderately steep, lateral slopes moderately steep but more so than the
anterior one. Interarea moderately long, strongly curved, apsacline. Lateral pro-
file moderately strongly convex and with the greatest curvature in the posterior
half.

Pedicle interior with moderately strong teeth and thick dental plates that con-
verge slightly toward the floor of the valve. Crural fossettes narrow but deep.
Muscle area confined to the delthyrial cavity. Posterior portion of pallial trunks
poorly defined.

Brachial valve gently convex in lateral profile, very broadly convex in anterior
profile. Umbonal region moderately swollen. Sulcus originating less than a
millimeter anterior to the beak, narrow and shallow, not reaching the anterior
margin in adult shells. Flanks bounding the sulcus moderately convex with long
gentle posterolateral slopes to the posterolateral extremities which are somewhat
flattened.

Brachial interior with moderately long brachiophores, supported by shell sub-
stance deposited along their lower edge. Sockets moderately deep. Notothyrial
platform swollen in adults ; cardinal process simple, thickest anteriorly and taper-
ing posteriorly to a thin septum. Muscle field indistinct.

Measurements in mm.—

Length Width ae Thickness
Paratype (pedicle valve 116866b) ..... 0.7 10.6 09.6 14
es Comal tio) DE OGOGS))) seers 8.9 10.1 9.9 ?
r (brachial valve 116866d) .... 9.6 11.8 10.3 ?
a ris: So (9 1686680 1s. . 2006 T1-7 10.6 ?

x (both valves 116866g) ....... 10.2 10.6 10.1 4.5

296 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types —Holotype: 116866c; figured paratypes: 109799a-e, 116866a,e,f; un-
figured paratypes: 116866b,d,g.

Horizon and locality —Chatham Hill formation in Virginia: On the Grayson
Farm, 4 miles southwest of Bland, Bland County; north slope of Walker Moun-
tain, 1.2 miles S. 31° E. of Sharon Springs, Burkes Garden (15’) Quadrangle.

Discussion.—This species has some of the external expression of O. rotundi-
formis but differs in having less costae, lesser convexity of the pedicle valve,
somewhat more convex brachial valve, and a more strongly apsacline interarea.
This species is common in the lower Chatham Hill near Sharon Springs.

CRTHAMBONITES BIELSTEINI Cooper, new species
Plate 36, B, figures 9-18

Shell of about medium size for the genus, longitudinally semielliptical in out-
line ; length and width equal, or wider than long. Hinge slightly narrower than
the greatest shell width which is at about the middle. Lateral margins gently
rounded; anterior margin somewhat narrowly rounded. Surface costate, costae
15 to 18 in number, subangular and with interspaces narrower than the width
of the costae.

Pedicle valve unevenly convex in lateral profile with the greatest convexity
in the posterior half, the front half somewhat flattened. Anterior profile with
narrowly rounded summit and steeply sloping sides. Umbo subcarinate and pre-
umbonal region swollen and produced anteriorly as a low fold which becomes
nearly obsolete at the front margin. Flanks flat in profile with moderately steep
slopes. Anterior slope not so steep as the lateral ones. Interarea short, curved,
gently apsacline.

Brachial valve with gently convex lateral profile but with the greatest curva-
ture in the umbonal region. Anterior profile a slightly convex arch slightly de-
pressed medially. Sulcus originating on the umbo, expanding anteriorly, shallow
throughout its extent and occupying about 4 mm. at the front of the valve. Flanks
very gently convex. Cardinal extremities depressed noticeably. Interarea short,
anacline.

Measurements in mm.—

Hinge
Length Width width Thickness
TOU oer cree « paacetieaselnaeced 11.5 11.8 9.3 5.6
Figured specimen (109801) ...... 10.9 12.1 10.0 ?

Types.—Holotype : 1098038 ; figured paratype: 109803b; unfigured paratypes :
109803¢,d ; figured specimens: 109845a, 109801.

Horizon and locality—Martinsburg formation (Salona equivalent) in Vir-
ginia: About 14 miles north of Staunton.

Oranda formation in Virginia: 0.6 mile northwest of Linville Station, Broad-
way (15’) Quadrangle.

Benbolt formation in Virginia : + mile east of Speers Ferry, Clinchport (T.V.A.
188-NW) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 297

Shippensburg formation in Pennsylvania: Railroad cut 1.7 miles southwest
of Marion, Chambersburg (15’) Quadrangle.

Shippensburg formation (Pinesburg member—shaly beds between Echino-
sphaerites and lower Nidulites zones) in Maryland: On U. S. Highway 40, just
west of Conococheague Creek, 7 miles west of Hagerstown, Williamsport (15’)
Quadrangle.

Discussion —Orthambonites bielsteini most nearly resembles O. buttsi Schuch-
ert and Cooper and O. mostellerensis, new species. From the former it differs
in its less transverse outline and less prominent median sulcus on the brachial
valve. From the latter O. bielsteini differs in having less numerous and more
narrowly elevated costae.

ORTHAMBONITES BIFURCATUS Cooper, new species
Plate 34, A, figures 1-6

Shell of about medium size for the genus, wider than long with the hinge con-
siderably narrower than the greatest shell width which is at the middle. Cardi-
nal extremities obtuse. Sides fairly strongly rounded; anterior margin broadly
rounded. Surface marked by narrow, elevated, subangular costae that bifurcate
at various distances from the beak. Including bifurcations, about 60 costae occur
along the anterior margin.

Pedicle valve with lateral profile moderately convex and with the greatest
curvature in the posterior half. Anterior profile moderately convex with long
and moderately steep slopes. Posterior margins curving away from the beak
which protrudes conspicuously. Umbo swollen and continued anteriorly as a
low fold to the front margin. Lateral areas sloping gently to the margins, the
slopes steepening to the umbonal slopes which are short and abrupt. Interarea
short, curved, apsacline.

Brachial valve less deep than the pedicle valve, gently convex in both profiles.
Median sulcus originating at the umbo and extending to the anterior margin,
deepening and widening anteriorly to occupy about one-third the width at the
anterior margin. Flanks gently swollen with short concave and steep lateral
slopes. Posterolateral extremities flattened. Interarea short.

Measurements in mm.—
Hinge

Length Width width Thickness
PPOIDE. cyst celoyeis evans» ois ¥ arden < 11.7 14.6 10.4 5.7
Paratype (100798g) ........... 10.0 12.3 9.2 5.0
$ (100 708d) i aes 9.6 12.3 8.9 4.4

Types——Holotype: 109798e; figured paratype: 109798g, 116869; unfigured
paratypes: 109798a-d,f,h,i.

Horizon and locality—Upper Pogonip group (Rhysostrophia zone) in Ne-
vada: North side of Ikes Canyon about 1 mile above the entrance, east side of
Toquima Range, Roberts Mountains (1°) Quadrangle.

Discussion—This species is characterized by the strong bifurcation of the
costae, a feature that will distinguish it from most members of the genus. It differs

298 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

from O. divaricatus in having a shallower brachial sulcus, narrower and more
elevated costae, and more numerous bifurcations of the costae.

The interior of a pedicle valve is revealed in one specimen and shows a short
and narrow delthyrial cavity with the usual orthoid musculature, but a low ridge
extends anteriorly nearly to the middle of the valve. This ridge is much longer
than the one in O. divaricatus.

ORTHAMBONITES BLOUNTENSIS Cooper, new species
Plate 35, C, figures 26-34
Hebertella ? sp. Butts, Virginia Geol. Surv. Bull. 52, pt. 2, pl. 73, figs. 31-33, 1942.

Shell small for the genus, wider than long; hinge forming the greatest width
of the valves. Cardinal extremities slightly acute. Lateral margins gently curved
and sloping slightly medially. Anterior margin broadly rounded. Anterior com-
missure slightly sulcate. Ornamentation consisting of 17 or 18 broadly subangu-
lar costae.

Pedicle valve moderately convex with the greatest convexity in the swollen
umbonal region. In anterior profile the convexity is moderate. Lateral slopes
flat and moderately steep. Interarea curved, slightly apsacline. Beak incurved.
Muscle area confined; median ridge thick and short. Interior with stout teeth,
deep fossettes, and thick, short dental plates. Adductor track thickened.

Brachial valve gently convex in lateral profile ; median sulcus narrow, occupy-
ing one-third the width. Sulcus occupied by two costae. Flanks bounding sulcus
gently swollen. Cardinal extremities depressed; slopes to extremities gentle,
concave. Beak inconspicuous ; interarea moderately long. Interior having a nar-
row notothyrial cavity, simple cardinal process and stout brachiophores.

Measurements in mm.—Holotype, length 7.8, dorsal length 6.6, width 9.1,
hinge width 9.8, thickness 4.5.

Types.—Holotype: 109812h; figured paratypes: 109812a-c; unfigured para-
types: 109812d-g,i,].

Horizon and locality—Arline formation in Tennessee: North side of wagon
road in glade, { mile southeast of Friendsville; 100 yards southwest of Negro
Cemetery, 4 mile northeast of Friendsville, Concord (T.V.A. 138-SW) Quad-
rangle.

Arline formation in Virginia: In the quarry just north of Marion, Marion
(T.V.A. 218-SE) Quadrangle.

Discussion.—This species is approximately intermediate between O. buttsi and
O. bielsteini. The former is larger and wider and with more distant costae. In
size and form O. bielsteini is somewhat larger but is more elongate and has a
deeper and wider sulcus on the brachial valve. It differs from O. rotundiformis
in its greater width and less prominent internal markings.

ORTHAMBONITES BRACHIOPHORUS Cooper, new species
Plate 36, E, figures 32-39

Shell large, suggesting a Dinorthis in appearance, wider than long with obtuse
or right angular cardinal extremities. Hinge as wide as the width at the middle or

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 299

slightly less. Lateral margins gently rounded ; anterior margin broadly rounded.
Anterior commissure rectimarginate. Surface marked by 30 to 32 strong, broadly
rounded costae having interspaces about the same width as the costae. Inter-
spaces marked by fine radial costellae and strong concentric fila, the latter best
developed on the median and posterior parts but the radial costellae best shown
along the anterior parts.

Pedicle valve moderately convex in lateral profile with the most convex por-
tion located in the posterior half, front half flattened. Anterior profile with flat-
tened sides and narrowly rounded crest at the middle ; beak prominent forming an
angle of 153°. Median region moderately swollen with moderately steep slopes to
the posterolateral extremities, the slopes becoming less steep anteriorly ; anterior
slope long and gentle. Interarea moderately long, apsacline. Muscle area small
and narrow for such a large valve occupying less than a third the length. Dental
plates short and receding; pallial impression indistinct.

Brachial valve slightly convex in anterior and lateral profile; sulcus originat-
ing at the posterior margin, narrow and shallow and extending to about the
middle of the valve where it is lost in the general convexity of the surface. Flanks
slightly swollen; cardinal extremities flattened. Interior with narrow and short
but moderately deep notothyrial cavity ; cardinal process a thin septum ; brachio-
phores long and slender; median ridge stout, reaching to the middle. Pallial
impressions indistinct.

Measurements in mm.—

Hinge
Length Width width Thickness
Holotype (pedicle valve) ...... 20.7 24.5 20.7 57
Raratype: GiOoS35p)) Gisec.e-< + 16.2 20.0 10.5 2.0

Types.—Holotype: 109835c; figured paratypes: 109835a,b,d,f ; unfigured para-
type: 109835e.

Horizon and locality—Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quad-
rangle.

Botetourt formation in Virginia: Opposite road intersection with Hays
Creek, 2 miles northwest of Brownsburg, Lexington (15’) Quadrangle; road to
Smyth Gap, 3 miles southwest of Clinchburg, Glade Spring (T.V.A. 212-SE)
Quadrangle.

Discussion.—This species can be recognized by its large size and the strong
concentric ornamentation between the costae. Specimens from the locality 2 miles
northwest of Brownsburg measure over 30 mm. in width and about 25 mm. in
length. This is one of the largest members of the genus so far found in this
country. This species has some features of Hesperorthis as, for example, the
long slender brachiophores and the transverse form of the pedicle valve. The
few specimens showing the delthyrium have no trace of a pseudodeltidium but
traces of lateral (deltidial?) plates are present. The size and ornamentation will
distinguish this species from all others herein described (see O. neumant).

300 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ORTHAMBONITES BUTTSI (Schuchert and Cooper)
Plate 36, D, figures 21-31
Orthis crasicosta Butts (not Pander 1830), Geol. Surv. Alabama, Special Rep. 14, p. 114,
116, pl. 26, figs. 14-15, 1926.

Orthis buttsi ScHUCHERT and Cooper, Mem. Peabody Mus. Nat Hist., vol. 4, pt. 1, p. 75,
footnote, 1932.

Shell of medium size, wider than long and with the hinge forming the great-
est width or slightly narrower. Lateral margins gently curved and sloping medi-
ally; anterior margin broadly curved. Anterior commissure very gently sulcate.
Costae direct, strong, subangular, numbering 19 on the pedicle valve. Entire sur-
face covered by fine radial threads.

Pedicle valve moderately convex in both profiles. Greatest convexity located
in the posterior half; the median costa a little elevated and forming the center of
a low fold that extends from the beak to the anterior margin. Flanks flattened ;
slopes to lateral margins gentle. Interarea curved, moderately apsacline; beak
incurved. Interior with deep but short delthyrial cavity; nearly obsolete dental
plates, short median thickening anterior to muscle area.

Brachial valve slightly convex in lateral profile, nearly flat and slightly de-
pressed in the middle in anterior profile. Sulcus shallow and narrow, occupied
by 2 costae, occupying about one-quarter the width at the anterior margin.
Interarea short; beak inconspicuous. Flanks bounding sulcus slightly swollen
with concave slopes to the cardinal extremities. Interior with low median ridge
not meeting the center, moderately stout brachiophores supported by shell de-
posited in notothyrial cavity. Cardinal process a simple ridge.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Flolotypie Sends. os D0 eee ac ok 11.4 10.2 rey 12.4 5.4
Hypotype (109808a) ....... 12.0 10.4 14.6 13.5 5.2

Types.—Holotype: 71497 ; figured hypotypes: 10g808a, 116870a-c ; unfigured
hypotypes: 109g808b,c, 116870d-f.

Horizon and locality.—Little Oak formation in Alabama: 4 mile north of Pel-
ham ; on west side of U. S. Highway 31, 4 mile N. 10° E. of Pelham Station,
SW4iSW35 sec. 13, T. 20 S., R. 3 W., all on Bessemer Iron District (15’) Quad-
rangle; cut on L. and N. RR., $ mile northwest of Mosteller, Columbiana (15’)
Quadrangle: intersection Bailey Gap road with main road, SWiSW3 sec. 13, T.
19 S., R. 2 W., 1 miles northeast of Newhope Church, Vandiver (15’) Quad-
rangle.

Discussion—The closest species to this one is O. angulatus from the Arline
formation at Riverdale, near Knoxville, Tenn. This species differs from O. buttsi
in its larger size, more numerous angular costae and stronger fold on the pedicle
valve.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 301

ORTHAMBONITES DINORTHOIDES Cooper, new species
Plate 33, E, figures 20-27

Shell of moderate size, wider than long, with the length equal to about two-
thirds the width. Hinge slightly narrower than the greatest shell width which
is located near the middle. Cardinal extremities obtusely angular. Lateral mar-
gins gently rounded; anterior margin broadly rounded. Anterior commissure
slightly sulcate. Surface costate with the number of costae varying from 21 to
25. Costae narrowly rounded and with interspaces wider than the ribs. Inter-
spaces marked by fine radial and concentric lines.

Pedicle valve very gently convex in lateral profile with greatest convexity lo-
cated at the umbo; anterior profile moderately convex. Beak well defined,
projecting a little posterior to the posterior margin, obtuse, umbo narrowly
swollen. An ill-defined fold formed at the umbo by the central 3 costae. Fold
best defined in the posterior half but flattened at the front where there may
be a shallow depression in its place.

Brachial valve gently convex in lateral profile ; gently convex in anterior profile
and with the center sulcate. Sulcus narrow and shallow and containing 2 costae.
Sulcus originating at the umbo and extending to the front margin. Flanks of
shell gently convex bounding the sulcus. Slopes to cardinal extremities gentle ;
posterolateral extremities flattened.

Interiors —Muscle area of pedicle valve more elongate than usual in the genus
and with a truncate anterior. Diductor scars elongate but adjustor scars small
and inconspicuous. Cardinal process with short shaft and narrow myophore.

Measurements in mm.—

Hinge
Length Width width Thickness
Holotype (pedicle valve) ............ 13.2 17.5 16.8 2.5?
Paratype (brachial valve 1og821a) ... 15.6 21.0 15.0? 1:75?

Types.—Holotype: 109823b; figured paratypes: 109821a,d, 109822a,b,
109823a,c,d; unfigured paratypes: 109821b,c,e,f, 109822c-h, 109823e-h.

Horizon and locality.—Oil Creek formation in Oklahoma: Sec. 14, T. 2 S., R.
1 E., about 5 miles north-northwest of Springer, Murray County; 3 miles east
of Pooleville, Murray County ; 614 feet above the base on west side U. S. High-
way 77, NELNE3 sec. 25, T. 2 S., R. 1 E., vicinity of Springer, Carter County.

Discussion.—As the name of this species implies, it is quite similar to the genus
Dinorthis. The dinorthoid features are in the interior rather than on the exterior.
The elongate diductor scars which flare a little laterally at their extremities, and
the truncate front of the muscle field are most suggestive of Dinorthis. Similari-
ties to this genus also occur in the brachial valve. The cardinal process with a
well-defined myophore suggests Dinorthis, but its form and shaft are more like
that of Orthambonites. Although the muscle field, like the cardinal process, sug-
gests Dinorthis, the small development of the adjustor scars and fine radial orna-
ment suggest Orthambonites rather than Dinorthis.

Orthambonites dinorthoides reminds one of O. paucicostata Ulrich and Cooper

302 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

from the Upper Pogonip of Nevada but differs in having wider valves with
narrower and less distantly spaced costae.

ORTHAMBONITES DIVARICATUS Cooper, new species
Plate 33, A, figures 1-3

Shell of about the usual size for the genus, valves unequally convex, length
equal to four-fifths of the width; hinge slightly narrower than the greatest shell
width which is located slightly anterior to the middle. Cardinal extremities
slightly obtuse. Anterolateral margins somewhat narrowly rounded, anterior
margin broadly rounded. Anterior commissure slightly sulcate. Surface marked
by strong subangular costae on the center and flanks, a generation of finer costae
intercalated between the larger ones on the flanks and posterolateral extremities.
Spaces between the costae ornamented by low, rounded fila, about 5 to the milli-
meter near the middle.

Pedicle valve moderately convex with the maximum convexity near the mid-
dle; anterior profile broadly convex. Beak small, incurved, protruding beyond
the posterior margin. Median portion of valve forming an ill-defined fold and
bearing the 3 largest costae. Flanks gently convex in anterior profile; antero-
lateral slopes gentle but the posterolateral slopes moderately steep. Interarea
only slightly curved, apsacline. Delthyrium open. Dental plates short, reced-
ing ; adductor field with small ridge extending anteriorly from thickened anterior
end.

Brachial valve gently convex in both profiles; sulcus originating less than a
millimeter anterior to the beak, shallow, widening anteriorly but occupying only
about one-quarter of the width. Flanks gently convex with short gentle slopes
to the cardinal extremities. Posterolateral extremities slightly flattened. Noto-
thyrial cavity shallow, median ridge short, cardinal process not developed.

Measurements in mm.—
Hinge

Length Width width Thickness
Holotype (pedicle valve) ............. 12.7 15.3 12.8 4.2
Paratype (brachial valve 109838b) ... 7.8 11.4 8.9 "
- (Gbeegtt se ppALOOESEC) tka iaye, MEO 12.4 9.9 ?

Types.—Holotype: 109838a ; figured paratype: 109838b ; unfigured paratypes:
109838c-e.

Horizon and locality —Effna-Rich Valley formations, in Virginia: Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This species is characterized by the strong intercalation of costae
between the primary ones and in this respect is unlike any other member of the
genus from Virginia described in this paper. Some resemblance exists between
this species and O. mycale Billings, but in the latter the muscular area of the
pedicle valve is smaller and the fold of the brachial valve and sulcus of the pedicle
valve are pronounced.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 303

ORTHAMBONITES EUCHARIS (Ulrich and Cooper)

Orthis eucharis UtricH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 99, pl. 14, E,
figs. 15-18; pl. 57, B, figs. 10-12, 14-16, 1938.

Types.—Lectotype: 95875c ; paratypes : 95875a,b,d-h.

Horizon and locality—Upper Pogonip group (mottled zone 700 feet below
the Eureka quartzite) in Nevada: Ridge east of Frenchman Flat, Las Vegas
(1°) Quadrangle.

ORTHAMBONITES ? EXFOLIATUS (Raymond)

Hebertella exfoliata RAyMonp, Amer. Journ. Sci., ser. 4, vol. 20, p. 370, 1905.

Plectorthis exfoliata (Raymond), Ann. Carnegie Mus., vol. 7, No. 2, p. 238, pl. 35, figs. 11,
12, IQII.

Orthis costalis HAut, Pal. New York, vol. 1, pl. 4, bis, fig. 4b, 1847.

The description and figures of this small orthid have never permitted accurate
understanding of the species, and this is true of the specimens available to the
writer. The specific name is aptly chosen because all the specimens available
have been broken from a somewhat dirty limestone and are much exfoliated, thus
not permitting an understanding of the true nature of the exterior. The interior
hitherto has never been described, except for the pedicle muscles.

A few specimens in sandy or silty matrix were subjected to treatment by acid
and the shell dissolved away from the matrix. The pedicle valves reveal strong
dental plates and a somewhat elongate muscle field having prominent diductor
scars.

The brachial valve cardinalia consist of a prominent but low notothyrial plat-
form having a prominent cardinal process thickened anteriorly. Brachiophores
are short and thick. It is difficult to tell, from the specimens available, if plates
support the brachiophores and are recumbent on the floor of the valve or if the
notothyrial platform is that common to the Orthidae. The structures lie too
close to the valve floor to be assigned to Plectorthis. The writer therefore tenta-
tively assigns the species to Orthambonites even though the interior is atypical
and the exterior suggests Desmorthis.

Horizon and locality—Day Point formation, vicinity of Chazy, Rouses Point
(15’) Quadrangle; 3 miles north of Plattsburg and Valcour Island, Plattsburg
(15’) Quadrangle.

ORTHAMBONITES FRIENDSVILLENSIS Cooper, new species
Plate 36, A, figures 1-8

Shell of medium size for the genus, strongly inequivalved, the pedicle valve
having the greater depth. Outline subquadrate; length and width nearly equal.
Lateral margins straight or slightly concave; anterior margin broadly rounded.
Cardinal extremities a right angle. Anterior commissure rectimarginate to sul-
cate. Surface marked by narrow, rounded costae separated by spaces narrower
than the costae. Costae ranging in number from 32 to 36, and with from 6 to 8
occupying a space of 5 mm. at the front.

304 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve moderately convex in lateral profile but more strongly convex
in anterior profile. Greatest convexity posterior to the middle. Umbo and post-
median region swollen; anterior half gently convex and sloping moderately
steeply to the anterior margin. Slopes to the cardinal extremities gently con-
cave, moderately steep. Interarea strongly curved ; beak incurved and overhang-
ing the delthyrium. Lateral plates well developed. Interior with short receding
dental plates, subcordate muscular area. Vascula media extending medially from
diductors, then becoming subparallel.

Brachial valve gently and evenly convex in lateral profile; gently concave in
anterior profile. Sulcus shallow and wide, shallowest at the front margin. Flanks
of shell slightly swollen; anterolateral areas depressed. Cardinal extremities
deflected slightly dorsally. Interarea short; beak inconspicuous. Interior with
long brachiophores, short median ridge, simple cardinal process and wide
adductor field.

Measurements in mm.—

Dorsal Hinge
Length length Width width Thickness
Holotype oii). #225 4 10.7 9.0 11.6 10.0 5.5
Paratype (100827c).. 8.5 7.5 9.5 75 4.6
cy (109827g).. 11.3 0.8 11.2 9.4 5.8

Types.—Holotype: 109827b; figured paratypes: 109827c,g,h; unfigured para-
types: 109827a,d-f,i-p.

Horizon and locality.—Arline formation in Tennessee: North side of wagon
road in glade, 4 mile southeast of Friendsville; 100 yards southwest of Negro
Cemetery, 4 mile northeast of Friendsville, Concord (T.V.A. 138-SW) Quad-
rangle; 1,500 feet south of the mouth of Burnett Creek, Shooks Gap (T.V.A.
147-NE) Quadrangle.

Discussion.—This species is characterized by its subquadrate form and the fine,
closely spaced costae. It resembles O. bellus but differs in having more finely
costate ornamentation.

ORTHAMBONITES MICHAELIS (Clark)
Orthis michaelis CLARK, Journ. Paleont., vol. 9, No. 3, p. 242, pl. 24, figs. 5, 6, 1935.—ULrIcH
and Cooper, Geol. Soc. Amer. Special Pap. 13, p. tot, pl. 14C, figs. 11, 12, 21, 23, 25-20,
1938.

Types.—Hypotypes: 91316a,b, 91318a,b; 91320a-d.
Horizon and locality—Swan Peak formation in Utah; Kanosh formation in
Utah.

ORTHAMBONITES MINUS Cooper, new species
Plate 34, D, figures 16-20

Shell small, wider than long, somewhat rectangular in outline; hinge slightly
less than the greatest shell width which is at the middle; sides gently rounded ;
anterolateral extremities narrowly rounded; anterior margin nearly straight;
anterior commissure sulcate ; surface marked by 35 to 36 narrowly rounded and
elevated costae separated by spaces slightly less than the width of the costae.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 305

Pedicle valve gently convex in lateral profile; greatest convexity located in
the posterior half; anterior profile broadly convex, somewhat sharply pointed
in the middle but with long, gently descending slopes; umbo gently swollen;
anterior to umbo a narrow fold consisting of 5 costae extends to the anterior
margin; flanks bounding fold gently swollen.

Brachial valve very gently convex in lateral profile with the greatest con-
vexity in the posterior half; anterior profile broadly convex and indented medi-
ally ; sulcus originating at the umbo and extending to the anterior margin where
it occupies about one-third the width. Flanks bounding sulcus somewhat swol-
len; posterolateral extremities flattened; umbonal slopes short and gentle.

Measurements in mm.—Holotype, length 4.5, brachial length 4.1, width 5.5,
hinge width 4.7, thickness 2.2.

Type.—Holotype: 116882.

Horizon and locality.—Tulip Creek formation (about go feet below top) in
Oklahoma: On east edge of sec. 25, T.2 S., R. 1 E., east side of U. S. Highway
77, 24 miles north of Springer, Carter County.

Discussion.—This species is similar to O. minutus in size but differs in having
more distantly spaced and fewer costae, a deeper sulcus and different proportions.

ORTHAMBONITES MINUSCULUS (Phleger)

Orthis minusculus PHuEGER, S. California Acad. Sci., Bull., vol. 32, pt. 1, p. 7, pl. 2, figs. 6, 7
(reprint), 1933.

Orthis minuscula Phleger, ULricH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 101,
pl. 15D, figs. 22-25, 1938.

Types.—Hypotypes : 91310a-d.

Horizon and locality—Mazourka formation, Inyo Mountains, Calif. Upper
Pogonip group (sponge beds), Ikes Canyon, Toquima Range, Roberts Moun-
tains (1°) Quadrangle, Nevada.

ORTHAMBONITES MINUTUS Cooper, new species
Plate 42, A, figures 1-9

Shell minute, wider than long with hinge about equal to the midwidth or
slightly wider or narrower; sides gently rounded; anterior margin broadly
rounded; surface marked by upward of 40 closely crowded, narrowly rounded
costae.

Pedicle valve gently convex in lateral profile with the greatest convexity at
about the middle; anterior profile broadly convex and with long lateral slopes.
Median region from umbo to anterior margin somewhat swollen to form an in-
distinct fold; interarea moderately long, strongly apsacline; teeth large; dental
plates small, receding, and bounding a broad and fairly deep delthyrial cavity.
Individual muscle scars not preserved.

Brachial valve with a gently convex lateral profile and a lobate anterior pro-
file; sulcus originating on the umbo, widening to the anterior margin where it
occupies nearly half the shell width; flanks bounding sulcus moderately swollen ;

306 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

cardinal process a thin ridge; median ridge formed by inner swelling produced
by sulcus ; notothyrial platform low; brachiophores short.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Paratype (pedicle valve 116883f)..... aur P 5.2 5.0 0.9
GaAs “AMULTOSS3D ie ea ? 3.2 3.0 0.6
3 (brachial valve 116883g).... ? 3.5 5.2 Ser 0.7
Cinien Cn AEEBOS SE Mis tour: Dyk 2.6 3.6 3.4 0.4

Types.—Holotype: 116883c; figured paratypes: 116883a,b,d,e; unfigured
paratypes: 116883f-h.

Horizon and locality—McLish formation (bed 45) in Oklahoma: On West
Spring Creek, sec. 6, T. 2 S., R. 1 W., Murray County.

Discussion—For differences between this species and O. minus Cooper, see
O. minus.

ORTHAMBONITES MOSTELLERENSIS Cooper, new species
Plate 35, A, figures I-10

Shell of medium size for the genus, subquadrate in outline, width slightly
greater than length. Lateral margins nearly straight; anterolateral extremities
broadly rounded; anterior margin truncate. Cardinal extremities a right angle.
Anterior commissure sulcate. Surface marked by about 15 broadly angular
costae.

Pedicle valve moderately convex with the greatest convexity posterior to
the middle. Median fold obscure, defined only in the anterior three-quarters.
Lateral slopes steep, gently concave. Interarea long, strongly incurved; beak
incurved. Teeth large; fossettes deep. Dental plates short; umbonal cavities
filled by callus. Muscle area small, slightly thickened.

Brachial valve slightly convex with a poorly defined median sulcus originat-
ing at the umbo and extending to the anterior margin where it occupies slightly
more than one-third the width. Sulcus occupied by 2 costae. Interior with short
brachiophores partly engulfed by callus. Notothyrial platform thickened ; cardi-
nal process stout.

Measurements in mm.—Holotype, length 11.5, dorsal length 10.0, width 12.3,
hinge width 10.0, thickness 5.0.

Types.—Holotype: 1o9810b; figured paratypes: 109810a,c,e; unfigured para-
types: 109810d,f,¢g.

Horizon and locality.—Little Oak formation in Alabama: Cut on L. and N.
RR., + mile northwest of Mosteller, Columbiana (15’) Quadrangle.

Discussion.—This species is characterized by its broadly angular costae and
its subquadrate outline. It is similar to O. rotundiformis but differs in its some-
what larger size and the broader costae and more quadrate outline. It differs
from O. blountensis in size and shape. It is about the same size as O. bielsteini
but the costation is coarser. It is readily distinguishable from its associate in
the Little Oak limestone, O. buttsi, by its more quadrate form and more distant
and broadly angular costae.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 307

ORTHAMBONITES MULTICOSTELLATUS Cooper, new species
Plate 33, B, figures 4-7

Shell of about medium size for the genus, wider than long and with gently
convex sides and strongly rounded anterior margin. Cardinal extremities ap-
proximately a right angle or slightly obtuse. Hinge equal to or slightly less than
the width at the middle. Surface marked by about 36 narrowly rounded and
closely spaced costae.

Pedicle valve gently convex in lateral profile and with the greatest convexity
in the umbonal region. Anterior profile swollen strongly in the middle and nar-
rowly rounded; lateral slopes flat and steep. Umbonal slopes steep and concave ;
umbo swollen and median portion inflated. Beak strongly incurved; interarea
curved, apsacline. Teeth small.

Brachial valve evenly and moderately convex in lateral profile; greatest con-
vexity in the median region. Anterior profile evenly and broadly convex;
umbonal region sulcate, sulcus small and disappearing in the general convexity
of the valve near the middle. Median region swollen. Median ridge short;
brachiophores short and stout ; cardinal process a simple ridge. Notothyrial plat-
form thickened.

Measurements in mm.—

Length Width Thickness
Holotype ‘(pedicle valve) oo... 0.00.00 10.9 TH7 4.4
Paratype (brachial valve 116875a) ......... 14.4 15.6 ? 3.4
e x5 Ler LOS7 SD) Seiad anne 10.9 14.2 FAG]

Types.—Holotype: 116876a; figured paratypes: 116875a; unfigured para-
types: 116875b-d, 116876b.

Horizon and locality Edinburg formation (Cyrtonotella zone) in Virginia:
Along the railroad about $ mile east of Strasburg Junction, Strasburg (15’)
Quadrangle.

Oranda formation in Virginia: Along railroad 4 mile west of Strasburg, Stras-
burg (15’) Quadrangle.

Discussion.—This species is characterized by its narrow and numerous costae
and in this respect differs from all other Virginia species of Orthambonites
described herein.

ORTHAMBONITES NEUMANI Cooper, new species
Plate 37, D, figures 15-28

Shell large, rectangular in outline with the length equal to about four-fifths
the width at the middle ; cardinal extremities acute ; sides slightly concave anterior
to the cardinal extremities ; anterior margin broadly rounded; valves subequally
convex; anterior commissure rectimarginate. Surface costate, costae rounded
and separated by spaces of equal width to the costae, about 32 costae along the
margin. Entire surface covered by fine concentric fila.

Pedicle valve evenly and gently convex in lateral profile; anterior profile
broadly and gently convex. Interarea moderately long, apsacline; beak small.

308 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Umbo gently swollen, the swelling continuing anterior to the front margin as a
broad, poorly defined fold. Lateral slopes long and gentle; umbonal slopes fairly
steep. Pedicle interior with short, stout dental plates, small teeth, and subquad-
rate muscle field. Pallial marks not preserved.

Brachial valve gently convex in lateral profile, broadly convex in anterior pro-
file, but with the median region sulcate and the sides appearing as two low swell-
ings. Umbo gently swollen; sulcus originating on the umbo, extending anteriorly
to the front margin. Sulcus narrow throughout, deepest in the median region and
becoming broad and shallow at the anterior margin. Flanks gently swollen with
short, steep slopes to the sulcus but long and gentle slopes to the margins. Bra-
chial interior with small shallow notothyrial cavity, thick notothyrial platform,
short brachiophores, short median ridge and simple cardinal process stoutest at
the anterior end.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype gacisid:. .padlievgwermee 18.9 ? 25.6 27.4 ?
Paratype (pedicle valve 116874a)... 17.6 ? 25.8 29.0 4.0
COs ee MELOSTAC nee 7ek ? 23.4 25.4 4.1
y (brachial valve 116874d).. ? 20.8 26.6 28.4 2.6
a Oe Ac) PROSTAR eo aw 17.7 19.7 23.4 aia ¥

Types.—Holotype: 116874e ; figured paratypes: 116874b,d,h,l,n,o,q ; unfigured
paratypes: 116874 a,c,f,g,i-k,m,p.

Horizon and locality—Tellico formation (sandstone No. 3 of Neuman) in
Tennessee: 0.3 mile northwest of Cold Springs School, Wildwood (T.V.A.
147-SE) Quadrangle.

Discussion —This is one of the largest Orthambonites so far seen in the Ordo-
vician of the Appalachians. It is characterized by its squarish muscle area in
the pedicle valve, the short brachiophores and the strong costae. It strongly re-
sembles Dinorthis and may be mistaken for that genus. The strongly convex ped-
icle valve, however, should eliminate the confusion. Of described species O. neu-
mani is most like O. dinorthoides. It differs in having more numerous costae,
larger size, and a squarer muscle field in the pedicle valve. This species differs
from O. brachiophorus, which it externally resembles, in having much shorter
brachiophores and a squarish muscle field in the pedicle valve.

ORTHAMBONITES OCCIDENTALIS Cooper, new species
Plate 34, B, figures 7-9

Shell of about medium size for the genus, the length about five-sixths the width.
Hinge slightly narrower than the greatest shell width which is at about the mid-
dle. Cardinal extremities slightly obtuse. Sides slightly rounded; anterior mar-
gin broadly rounded. Surface marked by 27 elevated, narrowly rounded, slen-
der costae separated by spaces about equal to the costae in width.

Pedicle valve moderately convex in lateral profile with the greatest convexity
at about the middle; anterior profile strongly convex with broadly rounded crest

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 309

and steeply sloping sides. Median region inflated ; anterior slope long and steep.
Posterolateral areas somewhat swollen and without steep slopes. Posterior mar-
gins forming an angle of 120° with the beak. Interarea moderately long, slightly
curved, apsacline. Delthyrium narrow, open.

Brachial valve gently and evenly convex in anterior and lateral profiles. Sul-
cus shallow, narrow, originating at the umbo and extending to the front margin
where it occupies less than a quarter of the width. Sulcus occupied by 4 costae.
Flanks gently convex. Umbonal region slightly swollen and with short but steep
umbonal slopes. Posterolateral areas slightly flattened. Interarea very short.

Measurements in mm.—Holotype, length 15.5-+, brachial length 13.0, width
18.0, hinge width 16.0, thickness 8.6.

Types.—Holotype: 109807a ; unfigured paratype: 109807b.

Horizon and locality—Upper Pogonip group (Rhysostrophia zone) in Ne-
vada: North side Ikes Canyon about 1 mile above the entrance, Toquima Range,
Roberts Mountains (1°) Quadrangle.

Discussion—This species is larger and more numerously costated than
O. minusculus and is distinguished from O. michaelis by its smaller, narrower,
and more distantly spaced costae, and the somewhat more transverse outline.

ORTHAMBONITES PARVICRASSICOSTATUS Cooper, new species
Plate 35, B, figures 11-25

Shell small, slightly wider than long, lateral margins gently rounded to nearly
straight, anterior margin narrowly rounded. Cardinal extremities obtuse or pro-
duced into minute ears. Anterior commissure sulcate. Hinge slightly wider or
slightly narrower than the shell width at the middle. Surface marked by 16 to
18 angular costae that widen anteriorly. Interspaces about equal to the width of
the costae, crossed by fine concentric fila.

Pedicle valve with lateral profile gently convex and with the greatest convexity
at about the middle. Umbo strongly convex. Anterior profile strongly humped
in the median region with the flanks descending moderately steeply to the lateral
margins. Median region of 5 largest costae somewhat elevated to produce a fold.
Interarea short, beak strongly incurved.

Brachial valve gently convex with the greatest convexity in the region posterior
to the middle. Beak small, umbo small, smooth, short. Sulcus originating just an-
terior to the umbo, widening rapidly to occupy about half the width. Four costae
occupy the sulcus. Flanks defined by a slight elevation of the 2 costae bounding
the sulcus. Posterolateral extremities flattened.

Pedicle interior with small teeth, and short, stout dental plates. Muscle area
slightly thickened, extending anterior to the anterior ends of the dental plates.
Brachial interior with short, stout brachiophores supported by a moderately
thickened notothyrial platform. Cardinal process thickened on the anterior face.

310 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge

Length length Thickness Width width
Holotype ois ee ate 7.0 6.3 3.0 7.0 6.8
Paratype (109832a)..... 5.6 5.0 3.0 6.5 5.4
7 (116871b)..... 7.5 6.7 4.0 acs 6.9
‘é ( TTO8720)) eséhinse 6.9 6.4 212 8.1 7.9
S (109832g)..... 5.0 48 3.0 5.8 5.2

Types——Holotype: 116872a; figured paratypes: 109832a,b, 116871b,
116872b,c; unfigured paratypes: 109832c-j, 116871Ia.

Horizon and locality.—Benbolt formation in Virginia: Wash on east side slope
in pasture, 0.2 mile south of middle fork of Moccasin Creek, 14 miles south of
Hansonville, Hansonville (T.V.A. 205-SW) Quadrangle; west slope of the hill
4 mile east of Cedar Point School, Hilton (T.V.A. 197-NW) Quadrangle.

Effna formation in Virginia: At Porterfield Quarry, 5 miles east of Saltville,
Maccrady (T.V.A. 218-NW) Quadrangle.

Botetourt formation in Virginia: Opposite road intersection with Hays Creek,
2 miles northwest of Brownsburg, Lexington (15’) Quadrangle; south side of
the road, 0.2 mile east of Strasburg Junction, Strasburg (15’) Quadrangle.

Chatham Hill formation in Virginia: 1.2 miles S. 31° E. of Sharon Springs,
Burkes Garden (15’) Quadrangle.

Discussion.—This species is characterized by its small size, strong angular
costae and nearly equal length and width. As now constituted this is a variable
species. The specimens from Porterfield Quarry are a little more strongly con-
vex than the Benbolt specimens, and the internal structures are more neatly de-
fined. The Benbolt specimens on the other hand have very thick dental plates
and a thickened callosity anterior to the muscle area of the pedicle valve. The
exterior impressions from northwest of Brownsburg show the concentric fila
well.

This species differs from O. blountensis in its more quadrate form and from
O. bielsteini in its smaller size and quadrate form, although the number of costae
is about the same for the two species.

ORTHAMBONITES PAUCICOSTATUS (Ulrich and Cooper)

Plate 33, D, figures 12-19
Orthis paucicostata ULRicH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 103, pl. 15, C,
figs. 16-21, 1938.
Types.—Holotype: 92841; paratypes: 92842a-e ; figured hypotypes ; 1098342,
b,m; unfigured hypotypes: 109834c-l.
Horizon and locality—Upper Pogonip group (lower part of Rhysostrophia
bed) in Nevada: Ikes Canyon, east side Toquima Range, Roberts Mountains
(1°) Quadrangle.

ORTHAMBONITES RECTANGULATUS Cooper, new species
Plate 34, C, figures 10-15

Shell rectangular in outline with the hinge equal to or slightly wider than the
shell at the middle; sides gently rounded; anterior margin broadly rounded;

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 311

biconvex, the pedicle valve with the greater convexity. Surface marked by
strong angular costae numbering about 16 to 18.

Pedicle valve gently convex in lateral profile and with the maximum convexity
in the midregion ; anterior profile broadly convex but with the median region
narrowly rounded and slightly elevated ; umbo narrowly swollen, the swelling con-
tinued to the front margin as a poorly defined fold; lateral slopes flat and gently
sloping ; interarea short, curved, gently apsacline ; beak incurved.

Brachial valve very gently convex with maximum convexity at the middle;
anterior profile broadly convex but with a narrow, V-shaped depression in the
middle; sulcus originating at the umbo widening anteriorly to the margin where
it occupies slightly more than one-third the shell width; flanks bounding sulcus
gently swollen; posterolateral extremities slightly depressed.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PIGUICY PE ces, outclsihs a seh 8.0 7.5 9.6 9.4 4.0
Paratype (109802a)..... 6.5 6.0 7.9 8.1 3.5

Types.—Holotype: 116877; paratype 1o9802a.

Horizon and locality—Shippensburg formation (Pinesburg member-just
above Erhinosphaerites zone) in Maryland: On U. S. Highway 40 at Wilson,
west side Conococheague Creek, 7 miles west of Hagerstown, Williamsport (15’)
Quadrangle.

Discussion.—This species is similar to O. blountensis in shape but differs in
having a less convex brachial valve, more elongate interarea, less convex pedicle
umbo, and less swollen pedicle valve.

ORTHAMBONITES ROTUNDIFORMIS Cooper, new species
Plate 34, F, figures 27-39

Small to medium size for the genus, thick-shelled; length and width nearly
equal or with the length exceeding the width. Lateral margins straight to slightly
curved ; anterior margin narrowly rounded. Hinge equal to or slightly less than
the greatest shell width. Cardinal extremities slightly obtuse or forming a right
angle. Surface marked by 18 to 24 low, subangular costae separated by spaces
wider than the costae.

Pedicle valve with the maximum convexity in the posterior half when viewed
from the side but in anterior profile strongly convex with slightly flattened flanks.
Posterior margin forming an angle of 120°. Beak strongly incurved ; umbo and
median part swollen and convex with flattened but steep slopes to the lateral
margins. Anterior slope less steep than the lateral ones. Interarea long, gently
apsacline. Teeth large with deep fossettes; dental plates stout, short; umbonal
cavities filled by callus. Muscle area confined to the delthyrial cavity.

Brachial valve strongly convex in lateral profile with the maximum curvature in
the posterior half and with the front half flattened. Anterior profile strongly con-
vex but with the crest of the curve slightly flattened. Sulcus poorly defined, origi-
nating at the umbo. Flanks swollen and with steep lateral slopes. Posterolateral

312 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

slopes steep. Interior with short stout brachiophores and much thickened noto-
thyrial platform and cardinal process. Median ridge short and low.

Measurements in mm.—

Hinge
Length Width width Thickness
FUGUGEVDE few oicigaddak-s a0 ns.e ueetin pes oe 8.8 7.9 7.2 ce
Paratype (pedicle valve 1o9842a)... 8.5 8.2 Te ?
e Oo" “ -109840a)... 8.6 8.7 8.0 ?
+ (brachial valve 109840j) . 9.8 10.1 9.6 ?
iH 6 af “ — 109843b). 7.9 8.9 6.9 ry

Types.—Holotype: 109843a; figured paratypes: 109840f-j, 109842a,b,
109843b,c; unfigured paratypes: 109840a-e, 109843d-m.

Horizon and locality—Athens formation (Christiania bed) in Tennessee: 600
feet S. 40° E. of the railroad crossing 1 mile northeast of the courthouse in
Athens, Athens (T.V.A. 125-NE) Quadrangle; roadside 24 miles south-south-
east of Riceville; 0.2 mile southeast of Britton Church, 24 miles northeast of
Charleston, Calhoun (T.V.A. 125-SW) Quadrangle; Cleveland-Benton road, 5
to 54 miles east of Cleveland, near old Climer, East Cleveland (T.V.A. 120-NE)
Quadrangle.

Discussion—The species is characterized by the strong convexity of both
valves, the brachial valve being unusually swollen for the genus. The distant
costae and the elongate form are other distinctive characters. The species differs
from O. blountensis in its elongate form and the more numerous and smaller
costae. It differs from O. friendsvillensis in the more distant costae and the more
convex brachial valve. It can be readily separated from O. parvicrassicostatus by
its more inflated valves and somewhat more numerous costae.

ORTHAMBONITES SUBCONVEXUS Cooper, new species
Plate 34, E, figures 21-26

Shell of about medium size for the genus, wider than long, with rounded cardi-
nal extremities and gently rounded lateral margins. Greatest width just posterior
to the middle. Anterior margin broadly rounded. Anterior commissure recti-
marginate. Ornamentation consisting of about 32 strongly elevated and narrowly
rounded costae. No finer ornamentation except concentric fila preserved.

Pedicle valve gently convex in lateral profile and with the most convex part
in the posterior third. Anterior profile very gently and broadly convex. Beak
forming an angle of 140°. Umbonal and median regions gently swollen and
descending to the anterior and lateral margins by gentle slopes, the anterior slope
having the lesser steepness. Interarea strongly apsacline, only slightly curved.

Pedicle interior with dental plates nearly obsolete; teeth small and with small
fossettes. Muscle field elongate with long and straight diductor scars and long,
narrow adductor field slightly raised and separating the diductors. Vascula media
divergent, indistinct.

Brachial interior with short and stout brachiophores supported by callus and
the thickened notothyrial platform. Cardinal process simple, stout. Median ridge
thick. Posterior adductor patches larger than the anterior ones.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 313

Measurements in mm.—

ui
Length Width width Thickness

Holotype (pedicle valve) ............ 13.5 16.4 12.5 3.5

Paratype (brachial valve 109844b).... 13.0 15.5? 13.4 ?

Types.—Holotype: 1098442 ; figured paratype: 109844b; unfigured paratypes:
109844c-e.

Horizon and locality—Oil Creek formation in Oklahoma (75 to 100 feet below
the top): On West Spring Creek, SW3 sec. 30, T. 1 S., R. 1 W., east of Poole-
ville, Murray County.

Discussion.—This species is most suggestive of Orthis michaelis that occurs
in the Swan Peak formation of Utah. The Oklahoma species differs in the lesser
convexity of both valves, the more inclined pedicle beak, the narrower pedicle
muscle field and the more ponderous cardinalia and median ridge.

O. subconvexus has some of the features of O. acutiplicatus and O. dinor-
thoides. It differs from both in having more closely spaced costae and from
O. dinorthoides in not having as elongate or such flaring pedicle muscles.

ORTHAMBONITES TENNESSEENSIS Cooper, new species
Plate 49, D, figures 16-21; plate 82, D, figures 13-20; plate 82,1, figure 4o

Shell subquadrate in outline, hinge slightly narrower than the greatest shell
width which is at the middle; sides gently curved; anterior margin narrowly
rounded ; biconvex, the pedicle valve having the greater depth. Surface marked
by 18 strong, subangular costae.

Pedicle valve fairly strongly convex in lateral profile and with the greatest
convexity in the median region; anterior profile somewhat narrowly convex;
umbo narrow and protruding ; median region swollen and with a somewhat in-
distinct narrow fold extending to the anterior margin; lateral slopes gently con-
cave and fairly steep in the posterolateral region. Interarea narrowly curved,
apsacline. Interior with short, thick dental plates; umbonal cavities filled; teeth
small but with deep fossettes. Lateral plates slightly developed ; diductor scars
protruding slightly anterior to the anterior end of the delthyrial cavity ; small but
thick ridge extending anterior to the muscle field.

Brachial valve moderately and evenly convex in lateral profile and with maxi-
mum convexity at about the middle; umbonal region narrowly curved; anterior
profile broadly convex and indented medially ; sulcus narrow and shallow on the
umbo, widening anteriorly, and occupied by 2 costae. Flanks bounding sulcus
gently swollen; posterolateral slopes short and steep. Interior with thickened
notothyrial platform, simple cardinal process and moderately long brachiophores ;
median ridge low, extending to the middle.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
BOGE UE sic inrsis «Act a» «00 sitter + ein .aiarals 10.9 0.7 10.9 9.2 6.4
Paratype (pedicle valve 116878a)... 9.1 ? 10.7 9.8 3.4

ii (brachial valve 116878c).. ? 8.7 10.8 9.2 2.2

314 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 116878b; figured paratype: 116878a,d, 116880, 116881;
unfigured paratype: 116878c.

Horizon and locality——Arline formation in Tennessee: 100 yards southwest
of the Negro Cemetery, 4 mile northeast of Friendsville, Concord (T.V.A.
138-SW ) Quadrangle.

Little Oak formation in Alabama: On U. S. Highway 31, 4 mile north of
the bridge, Pelham, Bessemer Iron District (15’) Quadrangle.

Botetourt formation in Virginia: On Virginia State Highway 114, 2.3 miles
west of the Montgomery-Roanoke County line, 12 miles northeast of Blacksburg.

Arline formation in Virginia: Quarry just north of Marion, Marion (T.V.A.
218-SE) Quadrangle.

Discussion —This species is very similar to Orthambonites rotundifornus but
is more strongly costate and the costae are more angular. O. tennesseensis is a
much more robust shell than O. rotundiformus.

ORTHAMBONITES TENUICOSTATUS Cooper, new species
Plate 38, E, figures 30-40

Shell small for the genus, wider than long, subrectangular in outline; hinge
narrower than the greatest shell width which is at the middle; sides nearly
straight or very gently rounded; anterior margin broadly rounded; surface
marked by 34 to 40 elevated and narrowly rounded costae separated by spaces
equal to or slightly wider than the costae ; costae appearing in 2 generations, one
at the beak and the other on the anterior slope of the umbo.

Pedicle valve strongly convex in lateral profile; greatest depth at about the
middle; anterior profile swollen in the middle and with moderately long and
gently convex, fairly steep, lateral slopes. Umbo swollen and beak incurved;
median region inflated to form an inconspicuous fold; anterior slope steep ; lateral
slopes gently inflated; umbonal slopes steep. Interarea moderately long, apsac-
line. Interior with small teeth, short, thick dental plates; umbonal cavities filled
with shell material ; delthyrial cavity deep; floor of muscle area slightly thickened
anteriorly ; vascula media and median ridge not developed.

Brachial valve gently convex in lateral profile; greatest depth located in the
posterior third ; anterior profile broadly convex and gently indented in the median
area; sulcus originating at the umbo, widening to the anterior margin where it
occupies slightly less than 2 mm. Flanks bounding sulcus gently inflated ; umbonal
slopes short and fairly steep; posterolateral extremities somewhat flattened. In-
terior with narrow, shallow notothyrial cavity, but thickened notothyrial plat-
form; cardinal process a low ridge, not well developed ; median ridge poorly de-
fined, extending to about the middle; brachial process short and stout.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PTO BRI i... ss alabe ls we. ddweaishew tices 3.5 3.3 4.3 a7, 1.8
Paratype (pedicle valve 116875h).... 6.5 ? 8.1 7.0 2.5

pS (brachial valve 116875f)... ? 5.4 6.8 6.2 1.2

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 315

Types.—Holotype: 116875b; figured paratypes: 116875a,c-e; unfigured para-
type: 116875f-n.

Horizon and locality —Lower third of the Pratt Ferry formation in Alabama:
0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species is characterized by its thin, elevated costae, strongly
inflated pedicle valve and the implantation of a generation of costae on the an-
terior side of the umbo. It is close to O. bellus from the Chatham Hill of
Virginia but is more finely and numerously costate and has a much more inflated
pedicle valve.

Genus NOTHORTHIS Ulrich and Cooper, 1938
Nothorthis Utricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 106, 1938.

NOTHORTHIS DELICATULA Ulrich and Cooper
Plate 38, D, figures 21-29

Nothorthis celicatula UtricuH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 106, pl. 17, C,
figs. 6-14, 1938.

The figures of this species are introduced for comparison with N. tarda from
the Pratt Ferry formation of Alabama.

Types.—Lectotype: G.S.C. 9067e; paratypes: G.S.C. 9067, 9067a-d,f,g.

Horizon and locality—Upper Canadian or younger, possibly an erratic in the
lower part of the Lévis shale, Lévis, Quebec.

NOTHORTHIS TARDA Cooper, new species
Plate 38, B, figures 3-15

Shell small, subrectangular in outline; wider than long, with the hinge nar-
rower than the midwidth; sides gently rounded ; anterior margin gently rounded ;
anterior commissure gently sulcate; shell multicostellate, costellae increasing by
intercalation in 3 generations, and numbering about 40, with 4 or 5 in a milli-
meter at the front margin.

Pedicle valve deep but having a moderately convex lateral profile with the
maximum curvature just posterior to the middle; anterior profile narrowly
domed. Umbo swollen and protruding beyond the posterior margin; median
region from umbo to anterior margin somewhat narrowly swollen to form a low,
rounded fold; flanks with steep slopes to lateral margin. Anterior slope gentle.
Interarea short, curved, apsacline. Teeth small; delthyrial cavity deep but with
small, short, slightly thickened muscle field ; dental plates, short, thick, receding.
Vascula media strong, narrow, widely divergent.

Brachial valve not so deep as the pedicle valve, fairly strongly convex and
with the maximum convexity at about the middle; anterior profile bilobed with
the center sulcate and the sides moderately domed; sulcus originating at the
umbo, widening and deepening to the anterior margin where it occupies some-
what more than a quarter of the width. Flanks bounding sulcus moderately in-
flated but with short steep sides. Interior with thick notothyrial platform, nar-

316 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

row notothyrial cavity; short and stout brachiophores, no cardinal process, and
large adductor field occupying a position on each side of the long and thick
median ridge. Pallial marks present, an oblique channel appearing just outside
the inner adductor scars and extending from the end of the brachiophores nearly
to the front margin.

Measurements in mm.—Holotype, length 3.0, brachial length 2.7, midwidth
3.5, hinge width 3.1, thickness 1.8.

Types.—Holotype: 116851d; figured paratypes: 116851a-c,e-j.

Horizon and locality—Pratt Ferry formation (lower third) in Alabama: 0.2
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species differs from N. delicatula Ulrich and Cooper from
the Lévis boulders in being somewhat smaller, much deeper and more convex
in lateral profile, and in having a rounder outline. Furthermore, the interior of
N. tarda has much more strongly impressed muscle scars and pallial marks.
Nothorthis tarda is abundant in the Pratt Ferry formation and can be obtained
by etching this limestone in acetic acid.

NOTHORTHIS TRANSVERSA Cooper, new species
Plate 38, F, figures 41-58

Shell small, rectangular in outline, with rounded sides and rounded postero-
lateral extremities. Anterior commissure deeply sulcate. Surface marked by
fine intercalated costellae, about 28 to 34 in number.

Pedicle valve moderately convex in lateral profile, strongly arched and some-
what narrowly rounded medially in anterior profile; median region and umbo
strongly swollen, the swelling continued anteriorly to form a fold marked
medianly by a strong costella extending from beak to margin; sides gently in-
flated and sloping steeply to the lateral margins.

Brachial valve moderately convex in lateral profile; broadly and gently con-
vex in anterior profile; sulcus originating at the umbo, wide and deep and oc-
cupying more than half the width at the front margin. Flanks bounding sulcus
gently inflated and with gentle slopes.

Measurements in mm.—Holotype, length 2.7, brachial length 2.4, midwidth
3.4, hinge width 2.9, thickness 1.5.

Types.—Holotype: 117986; figured paratypes: 117985a-e.

Horizon and locality.—Pratt Ferry formation (lower third) in Alabama: 0.2
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species differs from N. tarda in its more transverse outline.

Genus NICOLELLA Reed, 1917
Nicolella Reep, Trans. Roy. Soc. Edinburgh, vol. 51, pt. 4, p. 860, pl. 10, figs. 25-27, 1917.—
ScHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 77, 1032.
The features that distinguish Nicolella are not in themselves distinctive but

as a combination are quite characteristic. The ornamentation generally consists
of bold, strong angular costae with anterior bifurcations. The fine ornament

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER Sy

superimposed over the costae consists of concentric fila only ; the fine radial lines
often seen in Orthambonites are completely lacking. Nicolella differs from Orth-
ambonites and most other members of the Orthidae in the possession of promi-
nent chilidial plates. These are an unusual feature in the Orthidae and their
strong development in this genus is a very distinctive feature. Internally Nico-
lella is like Orthis.

In the United States one species, Nicolella agilera Willard, was placed in this
genus, but study of the type specimens shows it to be a decorticated example of
Productorthis. A genuine Nicolella is present in the upper part of the Chambers-
burg limestone, and specimens have been taken from Pennsylvania and Vir-
ginia. This species has the typical concavo-convex form and the chilidial plates
but is more finely costellate than usual for the genus. Another species occurs in
the Trenton limestone at Rochdale, near Poughkeepsie, N. Y.

NICOLELLA ACTONIAE (Sowerby)
Plate 39, E, figure 20

Specimen introduced for comparison with American species. Note chilidial
plates in brachial valve.

Figured specimen.—t1098838.

Horizon and locality—Lyckholm formation (F Ia): Moe near Taps, Estonia.

NICOLELLA ANGULATA Cooper, new species
Plate 42, H, figures 45-47

Shell large for the genus, concavo-convex; wider than long; hinge forming
the widest part of the shell; sides gently curved; anterior margin broadly
rounded ; anterior commissure broadly sulcate ; surface marked by strong angular
costae, 16 to 22, with bifurcations near the margins in large specimens.

Pedicle valve strongly convex in lateral profile and with a strongly rounded
umbonal region ; anterior profile strongly convex, with steep slopes to the lateral
margins ; median region inflated.

Brachial valve moderately concave and with the most concave part in the
median area; posterolateral areas flattened.

Measurements in mm.—Holotype, length 10.2, brachial length 9.2, width 12.5,
hinge width 14.4+, thickness 2.9.

Types.—Holotype: 116888.

Horizon and locality——Wappinger formation in New York: On Wappinger
Creek at Rochdale, 44 miles east-northeast of Poughkeepsie, Poughkeepsie (15’)
Quadrangle.

Discussion.—This species is quite unlike O. strasburgensis because of its
strongly angular, unusually strong costae.

318 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

NICOLELLA STRASBURGENSIS Butts
Plate 30, B, figures 7-11

Nicolella strasburgensis Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 110, pl. 95, figs. 32, 33,
1942.

Fairly large for the genus, wider than long and with hinge narrower than the
greatest shell width which is at or near the middle. Cardinal extremities
rounded. Lateral margins gently rounded, anterior margin moderately rounded.
Surface marked by strong angular costae that increase by intercalation: besides
the primary costae, two sets of costae appearing, one near the middle and the
other on the anterior and lateral margins. Strong, zigzag concentric growth
lines over entire surface.

Pedicle valve moderately convex in lateral profile and somewhat more strongly
convex in anterior profile. Umbonal region swollen, the swollen part continued
anteriorly nearly to the front margin to form a poorly defined fold. Slopes to
cardinal extremities fairly steep in adults. Cardinal extremities deflected slightly.
Interarea nearly othocline, slightly curved. Beak overhanging interarea slightly.
Delthyrium open. Interior with short dental plates and short cordate muscle
area. Diductor scars fairly large, adjustor scars small. Vascula media indistinct
but typically orthoid.

Brachial valve moderately concave with the deepest portion along the middle
line. Umbonal region concave. Flanks bounding longitudinal concave area nearly
flat. Interarea short hypercline. Chilidium small.

Measurements in mm.—Lectotype, length 20.3, width 23.1, hinge width ?
thickness 34+.

Types.—Lectotype: 97549a; figured paratype: 97549c; figured hypotypes:
109889a,b ; unfigured paratype: 97549b.

Horizon and locality—Oranda formation in Virginia: Along the railroad
tracks 4 mile east of Strasburg Junction, Strasburg (15’) Quadrangle ; 200 yards
east of Hupp Hill, 1 mile north of Strasburg, Strasburg (15’) Quadrangle.

Same formation in Pennsylvania: 1 mile northwest of Guilford Spring, Cham-
bersburg (15’) Quadrangle.

Discussion.—This species is characterized by its concavo-convex outline, the
fine angular costae, and the strong fila and growth lamellae. It differs from
members of the genus Cyrtonotella by its angular and coarser ornamentation and
the less flaring dental plates. The species is rare.

Genus CYRTONOTELLA Schuchert and Cooper, 1931

Cyrtonotella ScHucHERT and Cooper, Amer. Journ. Sci., ser. 5, vol. 22, p. 243, 1931; Mem.
Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 77, 1932.

Planidorsa ScHucuHeERT and Cooper, Amer. Journ. Sci., vol. 22, p. 244, 1931; Mem. Peabody
Mus. Nat. Hist., vol. 4, pt. 1, p. 100, 1932.

Cyrtonotella is another of the Baltic types that appears in the lower part of
the Middle Ordovician sequence of the Southern Appalachians. Specimens gen-
erally are rare and scattered but the locality 4 mile southwest of Catawba, Va.,

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 319

has yielded many. In general the genus can be recognized by its concavo-convex
outline and its usually fine costae or strong costellae. The outline is thus simi-
lar to that of Orthis ss. to which the genus is most closely related. The pedicle
interior is characterized by short and flaring dental plates and a muscle field
rhomboidal in outline. Inside the brachial valve the cardinalia are distinctive.
The brachiophores are characteristically orthoid but are very thin and incline
laterally from the notothyrial margin at a very low angle. They bound narrow
slitlike sockets. The cardinal process has a short shaft, and the myophore
may be more or less crenulated. The median ridge is short and the adductor
field small.

Cyrtonotella is commonest in the lower part of the Middle Ordovician. Speci-
mens in the collection, but too poor for identification or description, were taken
from the Meadow Marble and “Ottosee” in the neighborhood of Knoxville, Tenn.
It is also fairly common in the Tellico iron ore and limestones, but no specimens
in the collection were good enough for description or identification. The genus
ranges as high as the Benbolt but has not yet been seen above. Although Cyrto-
notella is fairly common in parts of the Appalachians, it is known from western
United States only from the shales between the Eureka sandstone and the upper
Pogonip, where it is rare.

In this monograph the genus Planidorsa Schuchert and Cooper is placed in
synonymy with Cyrtonotella. Opportunity to examine good brachial interiors of
Planidorsa shows that genus to have the characteristics of Cyrtonotella. The
pedicle interior of the genera is likewise very close. Schuchert and Cooper are
mistaken in their comparison of the pedicle musculature of Planidorsa to Multi-
costella. The musculature is actually almost identical to Cyrtonotella. Species
assigned previously to Planidorsa are usually more finely costellate than typical
Cyrtonotella, and the brachial valve is often less concave, but these features do
not at present seem sufficiently important for maintaining the name Planidorsa.
In absence of significant interior differences between the two genera it seems
best to submerge Planidorsa. At best, under modern methods it could be used
only as a subgenus.

CYRTONOTELLA BELLA (Schuchert and Cooper)
Plate 41, E, figures 20-25

Planidorsa bella ScHUCHERT and Cooper, Mem, Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 101,
pl. 16, figs. 24, 25, 1932.

Shell fairly large, planoconvex to gently concavo-convex in lateral profile,
wider than long with the hinge forming the widest part. Cardinal extremities
varying from nearly a right angle to alate. Lateral margins sloping medially;
anterior margin broadly rounded. Anterior commissure rectimarginate. Sur-
face multicostellate, costellae elevated and very narrowly rounded and sepa-
rated by interspaces about equal in width to the width of the costellae or
slightly wider. Costellae increasing by implantation and bifurcation in 4 gen-
erations. About 7 or 8 costellae in a space 5 mm. at the front margin of an adult.

320 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Costellae crossed by fine elevated fila, about 5 in 1 mm. near the center of the
pedicle valve.

Pedicle valve moderately convex in lateral profile with greatest convexity lo-
cated in the posterior half; anterior profile with a low hump medially from
which the sides descend in a slightly concave slope. Median region from umbo
to anterior margin moderately swollen to form a poorly defined fold. Umbo con-
vex, beak protruding slightly posterior to the posterior margin. Flanks flat or
slightly concave and descending gently to the margins. Umbonal slopes moder-
ately steep. Interarea slightly longer than the one on the brachial valve, strongly
curved, anacline to apsacline.

Brachial valve flat to gently concave in lateral profile, sulcus originating at
the beak, shallow, and generally disappearing in the anterior half to third which
is flattened to meet the anterior margin. Flanks flat to very gently convex;
cardinal extremities flattened. Interarea long, flat, anacline.

Brachial interior with erect cardinal process having a short shaft, trilobed myo-
phore in which the median lobe is carinate and elevated, suggesting that of Val-
courea. Median ridge short, not reaching one-third the length.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (110349a)........ 2Iat 20.3 26.8 24.7 5.1
ss Ci10948a 0.) 16.6 16.0 19.8 20.6 5.0
e €110348b) tion 13.4 12.9 16.0 14.7 ?

Types—Holotype: Y.P.M. S764; figured hypotypes: 110348a,b; measured
hypotype: 110349a.

Horizon and locality——Lincolnshire formation (Hogskin member) in Ten-
nessee: On the Sally Cleveland Farm, $ mile southwest of Washburn, Dutch
Valley (T.V.A. 154-SE) Quadrangle ; on the road to Washburn, 43 miles west-
southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle; Maynard-
ville Pike, 1.7 miles north of Hall Crossroads, Fountain City (T.V.A. 146-SW)
Quadrangle.

CYRTONOTELLA CRASSICOSTELLA (Schuchert and Cooper)

Planidorsa crassicostella ScHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4,
pt. 1, p. 101, pl. 16, figs. 22, 27, 1932.

Type.—Holotype: Y.P.M. 763.
Horizon and locality—Benbolt formation in Virginia: Speers Ferry, Clinch-
port (T.V.A. 188-NW) Quadrangle.

CYRTONOTELLA FASCICULATA Cooper, new species
Plate 41, A, figures 1-3
Shell small for the genus, more than 14 times wider along the hinge than long;

cardinal extremities alate, acutely angular. Lateral margins sloping inward ; an-
terior margin broadly rounded. Anterior commissure slightly sulcate. Surface

PART I CHAZYAN AND RELATED BRACHIOPODS-——-COOPER 321

multicostellate, costellae high and narrowly rounded, primary costellae strong and
standing above the others ; 3 generations of costellae are intercalated, the last gen-
eration appearing near the margin and tending, with the major costellae, to form
prominent fascicles. About 10 costellae including all sizes may be counted at the
median part of the front margin.

Pedicle valve moderately convex in lateral profile, gently convex and humped
slightly in the middle in anterior view. Median region slightly swollen; slopes to
cardinal extremities concave, gentle. Interarea short, curved, anacline.

Brachial valve slightly concave in lateral profile; sulcus originating almost at
the posterior margin, widening rapidly anteriorly and extending to the anterior
margin. Flanks flattened ; cardinal extremities flat and deflected slightly toward
the pedicle valve.

Measurements in mm.—Holotype, length 9.8, brachial length 9.2, width 13.0,
hinge width 17.1, thickness 2.3.

Type.—Holotype: 110356.

Horizon and locality.—Benbolt formation in Virginia: 4 miles east-northeast
of Gate City, Gate City (T.V.A. 188-NE) Quadrangle.

Discussion.—This species differs from P. bella in possession of more strongly
differentiated and more pronounced fasciculation of the costellae.

CYRTONOTELLA GRANDISTRIATA (Willard)
Plate 39, D, figures 16-19
Rafinesquina grandistriata WILLARD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 282, pl. 2, fig. 11, 1928.
Dinorthis ? sp Butts, Virginia Geol. Surv. Bull. 52, pt. 2, pl. 80, figs. 18, 19, 1942.

Shell large for the genus, wider than long and with the hinge forming the
greatest width. Cardinal extremities acute, alate. Lateral margins sloping medi-
ally; anterior margin broadly rounded. Surface multicostellate, costellae high
and narrowly rounded, appearing in 4 generations by implantation and bifurca-
tion. Primary and secondary costellae the stronger and tending to group the
ternary and quaternary costellae into fairly well marked fascicles.

Pedicle valve strongly convex in lateral profile in the posterior half, gently
convex in the anterior half. Anterior profile broadly convex with the median
part the most convex. Umbonal region moderately convex, but the region just
anterior to the umbo swollen and the valve somewhat inflated nearly to the front
margin along the median line. Slopes to cardinal extremities steep, those to the
anterior and anterolateral margins less steep.

Brachial valve moderately concave in lateral profile; umbonal region slightly
convex. Posterior to the middle the valve becomes moderately concave, and this
portion is the most concave part. Flanks slightly convex and cardinal extremi-
ties flattened.

Pedicle interior with widely flaring dental plates; brachial interior with short
and small brachiophores, small cardinal process.

Measurements in mm.—Hypotype (pedicle valve 109857), length 22.7, width
28.2, hinge width 35.2?, thickness 4.8.

322 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Figured hypotypes : 99262a, 109846a, 109854a; unfigured hypotypes:
99262b, 109846b, 109854b-e, 109857.

Horizon and locality.—Effna formation in Virginia: At Tilson Mill, 16 miles
northeast of Marion; McNutt Quarry, 12 miles southwest of Bland, Burkes
Garden (15’) Quadrangle; Porterfield Quarry, 5 miles east of Saltville, Mac-
crady (T.V.A. 218-NW) Quadrangle.

Botetourt formation in Virginia: Opposite road intersection with Hays Creek,
2 miles northwest of Brownsburg, Lexington (15’) Quadrangle.

Discussion.—The ornamentation and strong convexity of this species preclude
its assignment to Rafinesquina. Although the specimens available for study are
not good, as they are preserved in a crystalline limestone, details of the interior
obtained from the limestone specimens and a good silicified brachial valve indi-
cate affinites with Cyrtonotella. The species differs from C. virginiensis and
C. subplana in the stronger fasciculation of the costellae.

CYRTONOTELLA MAGNA Cooper, new species
Plate 41, C, figures 8-16; plate 41, D, figures 17-19; plate 50, A, figures 1-6

Shell large for the genus, wider than long with the hinge forming the widest
part; cardinal extremities acute in the young, obtuse in the adult; profile with
gently concave brachial valve and strongly convex pedicle valve; surface multi-
costellate, costellae elevated, narrowly rounded and separated by striae slightly
less than the width of the costellae; 7 to 8 costellae in 5 mm. at the front margin.

Pedicle valve strongly convex in lateral profile but with the greatest convexity
in the posterior half; anterior profile with median region somewhat strongly
humped and with long, moderately steep slopes to the sides; umbo and median
region swollen, the swelling continuing to the anterior margin indistinctly ; pos-
terolateral areas broad, flattened; umbonal slopes long and gently concave. In-
terarea short, narrowly curved ; beak strongly incurved ; umbo protruding slightly
posterior to the posterior margin.

Brachial valve very slightly concave in lateral profile; umbo depressed by a
broad sulcus which forms a prominent cavity in the median region of the valve
but disappears toward the anterior margin; flanks bounding sulcus flattened ;
posterolateral areas flat. Interarea short, anacline. Chilidial plates small; cardi-
nal process a short ridge; median ridge short, extending for about one-fourth
the length ; adductor field small ; brachiophores short and thin.

Measurements in mm.—Holotype, length 22.4, brachial length 21.2, width 28.9,
hinge width 27.7, thickness 6.9.

Types.—Holotype: 116897b; figured paratypes: 116897a,c, 116898, 1168992 ;
unfigured paratypes: 116897d; 1168g9b-e; figured specimen: 110353a.

Horizon and locality—lLower Sevier formation in Tennessee: On the east
side of the road 0.2 mile north-northwest of Gooseneck, Louisville (T.V.A.
138-SE) Quadrangle; 4 mile northeast of Miser, Louisville (T.V.A. 138-SE)
Quadrangle ; 1 mile by road northwest of Big Springs, Binfield (T.V.A. 139-NE)
Quadrangle ; 2 miles southeast of Friendsville, Binfield (T.V.A. 139-NE) Quad-
rangle; 1 mile south of Athens, Athens (T.V.A. 125-NE) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 323

Discussion—This species is difficult to separate from C. Della (Schuchert
and Cooper) because the details of the ornamentation are very close. Neverthe-
less, C. magna has somewhat stronger and more closely crowded costellae. Fur-
thermore, the brachial valve is generally more concave than that of C. bella. In
C. magna the brachial valve is fairly strongly concave in young individuals, but
the concavity becomes less anteriorly as the shell grows. C. bella on the other
hand is nearly planoconvex in the young and stays that way throughout life.

CYRTONOTELLA MINOR Cooper, new species
Plate 41, B, figures 4-7

Small for the genus, wider than long, nearly planoconvex ; surface costellate ;
costellae narrowly rounded, elevated with striae slightly wider than the costellae ;
11 costellae in 5 mm. at the front margin.

Pedicle valve strongly convex in lateral profile; greatest convexity at about
the middle; anterior profile narrowly convex in the median region with long and
moderately steep slopes to the lateral margins ; umbo narrowly swollen, the swell-
ing continued into the midregion and indistinctly to the anterior margin. Lateral
and umbonal slopes moderately steep. Umbo protruding posterior to the pos-
terior margin; beak incurved ; interarea short, orthocline.

Brachial valve with sulcate umbo ; sulcus narrow, deepening toward the middle
but becoming shallow and nearly obsolete at the front margin; flanks bounding
sulcus nearly flat.

Measurements in mm.—Holotype, length 11.9, brachial length 11.3, width
15.1 ?, thickness 4.0.

Types.—Holotype: 116900a ; unfigured paratype: 116900b.

Horizon and locality Lincolnshire formation in Tennessee: On the east side
of the road 4 mile north of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle ;
on the strike of the same bed as above, 4 mile northwest of Eidson, Kyles Ford
(T.V.A. 170-SE) Quadrangle.

Discussion.—This species is represented by three poor specimens only. It is
finely costellate and more so than any of the other species herein described. It is
evidently a rare species in the Lincolnshire and was found only in the shaly beds
at Eidson.

CYRTONOTELLA SUBPLANA Cooper, new species
Plate 39, C, figures 12-15

Shell large, wider than long, with the hinge about equal to the width at the
middle. Cardinal extremities a right angle. Lateral margins nearly straight ;
anterior margin fairly strongly rounded. Anterior commissure not folded. Sur-
face multicostellate, costellae low and subangular and separated by interspaces
wider than the width of the costellae. About 6 or 7 costellae occupying 5 mm.
at the median front margin; about 90 costellae occur on the valve. Costellae
crowded on the cardinal extremities. Fine ornament consisting of strong con-
centric fila.

Pedicle valve moderately convex in lateral profile; anterior profile with great-

324 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

est convexity in the median region; umbonal and posteromedian areas swollen ;
slopes to cardinal extremities steep, concave. Anterior and anterolateral slopes
moderately steep. Interarea short, strongly curved, anacline; delthyrium wide.

Brachial valve gently concave with the maximum cavity at about the middle;
sulcus originating almost at the posterior margin, thus producing a concave umbo.
Sulcus wide but shallow, disappearing anteriorly near the front margin. Flanks
flat to very gently convex. Cardinal extremities flattened. Interarea short;
chilidial plates small. Interior with short, wide, and stout median ridge. Cardi-
nal process erect, small; brachiophores short.

Measurements in mm.—Holotype, length 24.5, brachial length 22.1, width 28.8,
hinge width 27.8, thickness 5.2.

Types.—Holotype: 109860a ; figured paratype: 109860b ; unfigured paratype:
109860c.

Horizon and locality—Edinburg formation (Cyrtonotella zone) in Virginia:
Shaly beds just above the quarry 4 mile east of Strasburg Junction; ravine at
switch 4 mile east of Strasburg Junction; Strasburg (15’) Quadrangle.

Discussion—This species differs from C. virginiensis Butts by its proportion-
ately greater length in relation to width, less elevated and less crowded costellae,
and more elongate interarea of the pedicle valve.

CYRTONOTELLA SUBQUADRATA Cooper, new species
Plate 4o, B, figure 11; plate 82, E, figures 21, 22

Shell large for the genus, subquadrate in outline; cardinal extremities acute
in the young, obtuse in the adult ; sides gently rounded ; anterior broadly rounded ;
surface multicostellate, costellae narrowly rounded but separated by striae wider
than the costellae ; about 6 costellae in 5 mm. at the anterior margin.

Pedicle valve moderately convex in lateral profile with the greatest convexity
in the posterior half ; umbo strongly curved; anterior profile broadly convex with
long and flat lateral slopes to the margins. Anterior slope long and rounded.
Umbo swollen; median region swollen and somewhat inflated to the anterior
margin. Umbonal slopes long, gently concave.

Brachial valve gently concave in lateral profile with the greatest concavity in
the median region; umbo sulcate, sulcus shallow but deepening and widening
anteriorly to a point somewhat anterior to the middle where the deepest point is
reached ; near the anterior margin the shell is somewhat elevated and the sulcus
becomes obsolete ; flanks bounding sulcus nearly flat.

Measurements in mm.—Holotype, length 23.6, brachial length 22.3, width
28.9, hinge width 22.6, thickness 7.8.

Types.—Holotype: 111803; figured paratype: 116895.

Horizon and locality——Benbolt formation (Echinosphaerites beds) in Vir-
ginia: On the west slope of the hill 4 mile east of Cedar Point School, Hilton
(T.V.A. 197-NW) Quadrangle.

Benbolt formation in Tennessee: On the north side of the road, 1.1 miles
northeast of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 325

Discussion—tThis species differs from C. magna in its quadrate outline and
stronger costellation; it differs from C. bella in its more rounded margins and
its stronger concavity of the brachial valve.

CYRTONOTELLA VIRGINIENSIS Butts
Plate 40, C, figures 12-21; plate 40, D, figures 22-26
Cyrtonotella virginiensis Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 67, pl. 80, figs. 20, 21,
1942.

Shell large, strongly concavo-convex; wider than long with a hinge wider
than the shell at the middle. Cardinal extremities nearly a right angle to slightly
acute. Lateral margins sloping slightly toward the middle; anterior margin
broadly rounded. Anterior commissure not folded. Surface multicostellate, cos-
tellae appearing in 4 generations, all narrowly rounded, and separated by striae
about equal in width to the width of the costellae, about 80 costellae at the front
margin of an adult and about 7 to 9 in 5 mm. at the median portion of the front
margin. Costellae with a tendency to fasciculation along the margin.

Pedicle valve moderately convex in lateral profile with the greatest convexity
located in the umbonal region which is strongly curved. Anterior profile un-
evenly convex with the maximum convexity in the median region and the sides
descending moderately. Median region swollen from umbo nearly to front mar-
gin with gentle slopes to anterior and lateral margins. Interarea short, strongly
curved. Muscle area subquadrate with length and width about equal. Diductor
impressions large; adductor field elongate, very narrow.

Brachial valve moderately concave with the maximum concavity between the
median region and the anterior margin. Umbonal region flattened; the area an-
terior to the umbo slightly depressed to form a barely perceptible sulcus which
is lost in the concave anterior half.

Flanks flat to slightly concave ; cardinal extremities flattened. Interarea short,
hypercline. Interior with short median ridge extending for about one-third the
valve length. Brachiophores very short, widely divergent. Cardinal process short,
small. Notothyrial edges with traces of low chilidial plates.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (complete specimen 109865b). 20.5 18.1 26.3 26.8 3.0?
i (pedicle valve 109863)....... 21.6 ? 28.3 20.7 3
72 (brachial valve 116894a)..... 2 16.9 22.4 25.2 ?

Types.—Lectotype: 99263a; paratype: 99263b; figured hypotypes: 109863,
109865a,c, 109868a,b,e, 109870c; unfigured hypotypes: 109865b, 109868c,d,
109870a,b, 116894a,b; figured specimen: 109872.

Horizon and locality—Botetourt formation in Virginia: Northeast of Ca-
tawba ; junction of Virginia Highways 311 and 114, 4 mile southwest of Catawba,
Salem (15’) Quadrangle.

Arline formation in Tennessee: North side of wagon road in glade, 4 mile
southeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

326 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Arline formation in Virginia: Quarry on north side of Marion, Marion
(T.V.A. 218-SE) Quadrangle.

Discussion——This species is closest to C. subplana but differs in having a
more concave brachial valve, less numerous, narrower, and more elevated cos-
tellae and more swollen umbonal region on the pedicle valve.

CYRTONOTELLA ? sp. 1
Plate 32, F, figures 16-21

Under this heading is placed a lot of six specimens that have suffered some
distortion with the result that uncertainty exists as to their proper classification.
The shells are finely costellate with about 3 costellae to the millimeter. They are
concavo-convex to nearly planoconvex, and the brachial interiors are most like
Cyrtonotella. The species are suggestive of the fine-lined Cyrtonotellas that oc-
cur in the Hogskin member of the Lincolnshire formation, the Red Knobs forma-
tion (not described), and possibly the Benbolt formation.

Figured specimens.—109867a-d.

Horizon and locality—Botetourt formation in Virginia: On Hays Creek, 2
miles northeast of Brownsburg, Lexington (15’) Quadrangle.

TAPHRORTHIS Cooper, new genus
(Greek taphros, ditch)

Shell subquadrate to subrectangular in outline; sides rounded; anterior mar-
gin gently rounded to truncate; hinge straight, generally narrower than the
greatest shell width which is usually at or near the middle ; biconvex, the pedicle
valve having the greater convexity; surface costellate, costellae appearing in 5
generations, 1 at the beak, 1 on the anterior slope of the umbo, and 3 anterior
to the umbo; spaces between costellae and surface of costellae occupied by coarse
concentric fila.

Pedicle valve with delthyrium modified by more or less clearly defined lateral
plates ; teeth small, triangular, with shallow fossettes ; dental plates short, reced-
ing and divergent; umbonal cavities mostly filled by callus; delthyrial cavity
wide and deep; muscle field orthoid extended anterior to the ends of the dental
plates ; muscle field crudely heart-shaped ; diductor scars large, linear ; adductor
field small, divided by a median ridge extending as far as the middle; vascula
media not strongly impressed.

Brachial valve with fairly deep notothyrial cavity ; notothyrial platform thick,
continuous with the median ridge which is low, narrow, and extends to about
the middle of the valve; anterior of notothyrial platform somewhat excavated ;
brachiophores short, supported by callus on the inner edge of the notothyrial
platform; cardinal process poorly developed forming a low, inconspicuous ridge.
Adductor field large.

Genotype.—Taphrorthis emarginata Cooper, new species.

Discussion——Of described genera, Taphrorthis most resembles Glossorthis
Opik from the Middle Ordovician of Estonia. The two genera differ in many

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 327

details. For example the ornamentation of Glossorthis consists of strong sub-
angular costae whereas the ornamentation of Taphrorthis is costellate. Further-
more Glossorthis is not provided with more than an incipient sulcus in the young.
In adults the sulcus is completely lost.

Inside the pedicle valve Glossorthis frequently has a strong lifting of the
muscle field on a callosity to produce a pseudospondylium. In Taphrorthis this
tendency, although present, never takes a very tangible form. Inside the brachial
valve the cardinal process of Taphrorthis never forms the high and thick septum
that is characteristic of Glossorthis.

TAPHRORTHIS EMARGINATA Cooper, new species
Plate 38, A, figures 1, 2; plate 40, A, figures 1-10; plate 49, B, figures 5-10

Shell subrectangular in outline, attaining a width of about 2 inch; hinge nar-
rower than the greatest shell width which is at about the middle; cardinal ex-
tremities obtuse; sides gently rounded; anterolateral extremities narrowly
rounded ; front margin indented; biconvex, the pedicle valve having the greater
convexity ; surface multicostellate, costellae unequal in size, appearing in 4 gen-
erations, I just anterior to the beak, I anterior to the umbo, and 2 between that
point and the anterior margin; about 10 costellae in 5 mm. at the front margin.

Pedicle valve moderately convex in lateral profile and with the greatest con-
vexity in the posterior half; anterior profile moderately convex and with long
moderately steep slopes ; umbonal region inflated ; shallow sulcus developing an-
terior to umbo and causing emargination of the front margin; flanks gently
swollen ; posterolateral extremities small ; umbonal slopes short and steep; inter-
area curved apsacline ; beak incurved.

Brachial valve moderately convex in lateral profile and with the maximum
depth in the posterior half; anterior profile depressed medially but with some-
what narrowly rounded flanks bounding sulcus and steep, short lateral slopes.
Sulcus originating at the umbo and extending to the anterior margin where it
occupies a third the shell width ; posterolateral areas small; umbonal slopes steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Fiolotype .fididesias sss: 12.0 10.8 15.0 11.9 6.8
Paratype (116889c).. 8.9 7.9 12.4 10.4 4.7
si (116889b).. 8.9 8.2 11.4 ? 4.2

Types.—Holotype: 116889a; figured paratypes: 117983a,b, 116889b,c; un-
figured paratypes: 11688qd-f, 116890, 116891a-d.

Horizon and locality.—Little Oak formation in Alabama: In a cut on U. S.
Highway 31, 4 mile north of Pelham, Bessemer Iron District (15’) Quadrangle;
Bailey Gap road junction with Cahaba Valley road SW4SW35 sec. 13, T. 19 S.,
R. 2 W., 1} miles northeast of Newhope Church, Vandiver (15’) Quadrangle.

Arline formation in Tennessee: 100 yards southwest of the Negro Cemetery,
4 mile northeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—See T. peculiarts.

328 . SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

TAPHRORTHIS PECULIARIS Cooper, new species

Plate 38, C, figures 16-20; plate 30, A, figures 1-6; plate 108, B, figures 6-14;
plate 108, D, figures 19, 20

Of moderate size for the genus, wider than long and with the hinge narrower
than the greatest shell width which is located at about the middle. Cardinal ex-
tremities obtusely angular. Sides gently rounded; anterior margin truncated.
Surface multicostellate with 4 generations of intercalated costellae besides the
primary set. Strong concentric elevated lines cross the costellae and interspaces.
Twelve costellae of all sizes appear in a space of 5 mm. at the front of a valve
Ir mm. long.

Pedicle valve moderately convex in lateral profile and strongly convex in an-
terior profile. Beak erect and with prominent swollen umbonal region. Median
portion of valve full and with a moderately steep anterior slope. Lateral slopes
steep. Interarea long, curved, apsacline to orthocline; delthyrium open or par-
tially restricted by narrow lateral plates. Pedicle interior with small teeth hav-
ing moderately deep fossettes. Dental plates short, the umbonal cavities partially
filled by callus material. Muscle area typically orthoid with a cordate outline hav-
ing large diductor impressions and an elongate adductor field often slightly raised
anteriorly and producing an incipient pseudospondylium.

Brachial valve gently convex in lateral profile but broadly arched and depressed
medially in anterior profile. Beak small, protruding slightly posterior to the
posterior margin. Umbo sulcate, the sulcus produced anteriorly to the front
margin, widening in this direction but becoming shallower. Flanks bounding
sulcus gently swollen and with gentle anterolateral slopes but steeper slopes to
the cardinal extremities. Interior of brachial valve with a short median ridge
not reaching to the middle of the valve; notothyrial platform moderately thick
and united with the median ridge. Notothyrial cavity shallow ; cardinal process
a low, simple septum. Brachiophores short, slender and defining small, shallow
sockets. Adductor field small.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle valve) yee. 22 ste cjccte te ome 9.9 12.8 a7
Paratype (brachial valve 109883b).......... II.1 14.5 2.4

Types.—Holotype: 109883¢; figured paratypes: 109883b,e, 116892, 116893a,b,
117984a,b,e; unfigured paratypes: 109883a,d,f-j, 117984c,d.

Horizon and locality —Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Botetourt formation in Virginia: Opposite the road intersection with Hays
Creek, 2 miles northwest of Brownsburg, Lexington (15’) Quadrangle; north
of Virginia Highway 114, 2.3 miles west of Montgomery-Roanoke County line,
about 12 miles northeast of Blacksburg, Montgomery County.

Pratt Ferry formation (lower third) in Alabama: 0.2 mile southeast of Pratt
Ferry, Blocton (15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 329

Discussion.—This species differs from T. emarginata by its finer costellation,
and shallow sulcus becoming obsolete anteriorly.

PLEURORTHIS Cooper, new genus
(Greek pleuron, rib)

Shells ranging from small to fairly large, generally subrectangular to semi-
elliptical in outline ; biconvex, with the brachial valve generally the deeper ; hinge
wide, straight, usually equal to or slightly less than the greatest shell width; shell
sulcate in young stages but becoming uniplicate in the adult ; surface multicostel-
late ; shell fibrous, impunctate.

Pedicle valve with short receding dental plates, dental fossettes deep ; muscula-
ture orthoid ; delthyrium open. Brachial valve with short median ridge.

Genotype.—Pleurorthis fascicostellata Cooper, new species.

Discussion.—This genus is characterized by its fairly typical orthoid characters
combined with a peculiar ornamentation. The valves are biconvex, and the
brachial valves are sulcate in young and early mature stages. The sulcation, how-
ever, gives way to a more or less prominent plication. In adults and old shells
the plication is broad and prominent. The fold is generally low but the sulcus
in the pedicle valve is broad and deep. The great depth and breadth developed
in some specimens early led to the assignment of some species of this genus to
Sirophomena. Usually the multicostellate exterior combined with the convex
valves and the broad uniplicate commissure will separate this genus from other
orthoids.

PLEURORTHIS CONVEXA Cooper, new species

Plate 31, D, figures 15-21

Shell small for the genus, subquadrate to subelliptical in outline ; lateral mar-
gins narrowly rounded; anterior margin broadly convex; valves strongly con-
vex ; surface multicostellate to fascicostellate, 3 or 4 costellae to the millimeter
and bundled in groups of 3 or 4 at the front margin.

Pedicle valve fairly strongly convex in lateral profile and with the greatest
convexity at about the middle; anterior profile broadly convex and somewhat
carinate medially ; fold narrow and prominent on the umbo, extended forward
to the anterior margin; sulcus broad and shallow, defined in the front half;
posterolateral slopes concave and moderately steep. Dental plates divergent;
delthyrial cavity narrow.

Brachial valve with fairly deep and narrow sulcus extending from the umbo
to the anterior margin; lateral profile fairly strongly convex; greatest convexity
at about the middle; fold low and ill-defined but indented by the sulcus; anterior
profile broadly convex.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle valve) ....... 220% js-¢5 in 10.5 1.9?
Paratype (brachial valve 116844b).......... 10.0 13.8 2.8

“ at ps SY ETOOAAG) tects sheietee 7.9 10.8 2.3

330 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 116844e; figured paratypes: 116844a-d.

Horizon and locality —Boulders in the Mystic conglomerate in Quebec, Can-
ada: Range 6, Lot 20, 25 miles north of Mystic, Stanbridge Township.

Discussion.—This species is fascicostellate like P. fascicostellata but differs
in being smaller and much more convex in the profile of both valves.

PLEURORTHIS CORINNA (Billings)

Orthis corinna Bitirncs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 302, fig. 292, 1865.—
HAtt and CrarkeE, Pal. New York, vol. 8, pt. 1, p. 217, 1892.

Several specimens referred to this species resemble P. imbecilis (Billings) but
differ in being proportionately wider and more strongly costellate.

Type.—Hypotype: 66307.

Horizon and locality—Boulders in the Mystic conglomerate in Quebec, Can-
ada: Range 6, Lot 20, 25 miles north of Mystic, Stanbridge Township.

PLEURORTHIS COSTELLATA Cooper, new species
Plate 31, C, figures 11-14

Fairly large for the genus, subrectangular in outline ; sides moderately rounded ;
anterior margin broadly rounded ; surface marked by fine rounded costellae about
4 to the millimeter at the front margin of an adult shell.

Pedicle valve with moderately convex lateral profile and the greatest depth at
about the middle; anterior profile somewhat narrowly convex in the median area
but with long and gentle slopes to the margins; beak slightly protruding ; umbo
narrowly swollen; median portion of valve swollen; sulcus defined only as a
flattening of the anteromedian portion of the valve.

Brachial valve strongly convex in lateral profile and with the greatest con-
vexity in the median region; anterior profile strongly convex with the median
region swollen and the lateral slopes short and steep; umbo sulcate ; sulcus short
and narrow, dying out in the general swelling of the median region; postero-
lateral slopes short and concave. Fold poorly defined.

Measurements in mm.—

Length Width Thickness
Holotype (pedicle valve)...........sss.000 11.6 16.2 ? an
Paratype (brachial valve 116845c).......... 11.7 15.8 2.5

Types.—Holotype: 116845b ; figured paratype: 116845c; unfigured paratypes:
116845a,d,e.

Horizon and locality—Boulders in the Mystic conglomerate in Quebec, Can-
ada: In Stanbridge Township, Range 6, Lot 20, 24 miles north of Mystic; Range
6, Lot 21, 2.6 miles north and 4 mile east of Mystic.

Discussion.—This species is characterized by its very fine and fairly even
costellae and the lack of clearly defined fold and sulcus. It differs from P. imbe-
cilis which is finely costellate by its more robust form.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 331

PLEURORTHIS FASCICOSTELLATA Cooper, new species
Plate 31, E, figures 22-27

Shell large, transversely elliptical in outline; valves subequally convex ; hinge
slightly narrower than the greatest shell width which is at about the middle;
lateral margins gently rounded; anterior margin broadly rounded. Surface
marked by costellae of unequal size, about 8 in 5 mm. at the front margin.
Costellae tending to bundle in groups of 3, thus giving a fascicostellate appearance.

Pedicle valve moderately convex in lateral profile with the greatest convexity
just posterior to the middle; anterior profile broadly convex; umbo narrowly
convex and produced anteriorly as a faint swelling; sulcus broad, ill defined ;
lateral and posterolateral slopes gently concave. Interior of pedicle valve with
short dental plates and narrow delthyrial cavity.

Brachial valve with moderately convex lateral profile, most convex in the pos-
terior third; anterior profile broadly convex; sulcus narrow and deep at the
umbo and continuing anteriorly for two-thirds the length where it merges into
the ill-defined fold. Lateral slopes gently concave. Brachial valve as defined for
the genus.

Measurements in mm.—

Length Width Thickness

Holotype (pedicle valve) .................. 18.0 28.1 2a
Paratype ( “ SH TTGSAT DOES lhe! 12.7 19.7 2a
a (brachial valve 11684Ic).......... 16.8 27.8 3.5
rs NY Pen pELOSATC,) ager Paphos 14.2 23.3 3.0

Types.—Holotype: 117982; figured paratypes: 116841b-d,g,i; unfigured para-
types: 116841a,e,f,h.

Horizon and locality—Boulders in Mystic conglomerate in Quebec, Can-
ada: In Stanbridge Township, Range 6, Lot 20, 24 miles north of Mystic;
Range 6, Lot 21, 2.6 miles north and 4 mile east of Mystic.

Discussion.—This species is characterized by its strongly fasciculate ornamen-
tation and its large size. Indications are that the species attains a width of nearly
2 inches. The large shells are fairly strongly sulcate anteriorly and were origi-
nally mistaken for Strophomena although the ornamentation is not in accord
with such an identification. Pleurorthis fascicostellata is more transverse than
P, imbecilis and attains a much larger size.

PLEURORTHIS IMBECILIS (Billings)
Plate 32, B, figures 2-4
Strophomena imbecilis Bittincs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 219 (adv.
sheets, 1862), 1865.

Shell elliptical in outline ; surface marked by fine, narrowly rounded costellae,
3 to 4 in I mm. at the front margin.

Pedicle valve with lateral profile strongly convex in umbonal region but flat
anteriorly ; anterior profile broadly convex; sulcus broad and deep, originating
about 3 mm. anterior to the beak; sulcus bounded by 2 fairly strong plications ;

332 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

umbo somewhat swollen ; lateral and posterolateral slopes gently concave. Pedicle
valve with strongly divergent dental lamellae.

Brachial valve with lateral profile more convex than that of the pedicle valve,
most convex in the median and umbonal region; anterior profile broadly and
strongly convex; sulcus shallow, short and confined to the umbonal region;
median region broadly swollen to form an ill-defined fold; posterolateral slopes
steep and concave.

Measurements in mm.—

Length Width Thickness
Lectotype (pedicle valve 550b)............... iret 11.4 1.9?
Paratype (brachial valve 559)..........e000. 7.9 12.7 2.0

Types.—Lectotype: G.S.C. 559b; paratype: G.S.C. 559; figured hypotypes:
116842a,b, 116843.

Horizon and locality.—Table Head series in Newfoundland: Portland Creek ;
Table Point, Table Point Cove.

Discussion.—This species is characterized by its small size and the finely
costellate exterior. In these respects it differs from all other described forms of
this genus.

PLEURORTHIS TRITONIA (Billings)
Plate 31, F, figures 28, 29

Orthis tritonia Bituincs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 76, fig. 69 (adv.
sheets, 1862), 1865.—HaLL and Ciarke, Pal. New York, vol. 8, pt. 1, p. 217, pl. 7A,
figs. 12, 13, 1892,

Orthis ? tritonia (Billings) Utricn and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 103,
pl. 18C, figs. 12, 13, 1938.

Types.—Holotype: G.S.C. 807.
Horizon and locality—Probably of the age of the youngest boulders of the
Mystic Conglomerate in Limestone No. 2, Lévis, Quebec, Canada.

PLEURORTHIS sp. 1
Plate 32, A, figure 1

Shell of about medium size for the genus; subelliptical in outline; sides
rounded; anterior margin broadly rounded; surface marked by fairly coarse
costellae arranged in bundles of 3 at the anterior margin and with about 3 to the
millimeter.

Pedicle valve moderately convex; greatest convexity in the umbonal region;
anterior profile somewhat triangular with the median region swollen and some-
what narrowly rounded and the slopes flat, long, and moderately steep; fold
not well defined anteriorly ; sulcus not well defined.

Brachial valve moderately convex with the greatest convexity in the median
region; anterior profile broadly convex, depressed medially by the narrow sul-
cus; umbo sulcate; sulcus disappearing in the median swelling; fold ill defined.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 333

Measurements in mm.—

Length Width Thickness
Pedicle s valve: (LIOSA7) sic a. eyes. c wigs ca oli aye 10.5 14.8 2.5
Brachial valve (rl0s40)). =... wok eect ee ee 9.4 12.5 2.0

Figured specimen.—116846 ; described specimen: 116847.

Horizon and locality —Table Head series in Newfoundland: At Table Point;
south side of Stearing Island, Cow Head, Lower Head.

Discussion.—This species is suggestive of P. fascicostellata but differs in pro-
portions, size and details of the ornamentation.

PLEURORTHIS sp. 2
Plate 32, C, figures 5, 6

A fine silicified pedicle valve has the following characters: subquadrate in
outline ; sides gently rounded, anterior margin broadly rounded. Surface costel-
late, costellae bifurcating and somewhat bundled near the middle, fairly evenly
spaced along the anterior margin, about 2 to the millimeter.

Umbo swollen; sulcus originating at about the middle, broad and shallow but
producing a short tongue; folds bounding sulcus somewhat narrowly rounded ;
posterolateral and lateral slopes long and steep. Lateral profile convex with the
greatest convexity in the umbonal region. Anterior profile with steep sides but
somewhat sunken median region.

Interior with wide and deep delthyrial cavity; dental plates short and reced-
ing ; teeth small but with deep fossettes. Lateral plates along the delthyrial edge
narrow. Muscle area large but individual scars not visible in the specimen.

Measurements in mm.—116848, length 11.7, width 14.5+, thickness 5.0.

Figured specimen.—1 16848.

Horizon and locality—Lower middle part of the Table Head series in New-
foundland: North of Table Head.

Discussion.—This specimen may be conspecific with P. imbecilis, but the un-
usual preservation does not permit accurate comparison with the usual decorti-
cated specimens of P. imbecilis.

Subfamily PropucToRTHINAE Schuchert and Cooper, 1931

Aberrant and specialized Orthacea characterized by exceedingly short inter-
areas or none at all and having the exterior form of the productid brachiopod.
Muscles of the pedicle valve deeply entrenched ; brachial valve with much short-
ened brachiophores.

Genus PRODUCTORTHIS Kozlowski, 1927
Productorthis Koztowskt1, Bibl. Liberae Polonae, fasc. 17 (separate), pp. 1-21, 1927.—
ScHucHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 82, 1032.

This genus is characterized by its external resemblance to the productids of
the Carboniferous and Permian. The pedicle valve, like that of “Productus,” is
usually convex. Some details of the ornament are quite unlike those of “Pro-

334 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ductus.” Spines have not been observed in the Ordovician homeomorph, and a
strongly lamellose shell like that of Productorthis is not a characteristic feature
of the Carboniferous productids. Internally, of course, the resemblance to “Pro-
ductus’ is very remote except for the hinge.

The delthyrial cavity of Productorthis is deep, and the muscles occupying it
do not make a pattern readily recognizable as orthoid. The adductor field is very
wide and occupies most of the delthyrial cavity. On each side of this track occurs
a long, slender, and deeply impressed scar that can now only be interpreted as
the place of attachment of the diductor muscles. Schuchert and Cooper regarded
these scars as belonging to the adjustor muscles, but the Virginia specimens,
particularly the one illustrated on plate 56,B, figures 14 and 17, make it neces-
sary to revise this view. It will be noticed that a narrow pallial trunk extends
from the anterior end of these slender scars. These trunks are undoubtedly the
vascula media which always originate at the anterior ends of the diductor scars.
Adjustor marks were not definitely seen in any of the specimens, and it is as-
sumed therefore that if these muscles were present they were situated on the
sides of the delthyrial cavity and left no visible marks. In the Virginia material
the dental plates are not strongly marked because they are partially obliterated
by callus deposited in the umbonal cavities. In old specimens the dental plates
are not visible.

The interior of the brachial valve of Productorthis is as distinctive as that of
the pedicle valve, but the orthoid characters are more clearly retained. The
brachiophores are short and distinctly orthoid but are partially buried in callus
that surrounds their anterior ends to form a cuplike socket. The cardinal process
is large with a long oblique shaft that extends into the interior. The myophore
face is narrowly elliptical and bears a sharp, slender median carina. The postero-
dorsal extremity of the cardinal process is partially or wholly covered by a small
elliptical or circular plate which is undoubtedly a modified chilidium. The ad-
ductor field of the Virginia specimens, like their European relatives, are divisible
into 6 individual scars. The posterior pair are short and wide. The anterior
group is divisible into a larger median pair and a smaller outer pair. The median
ridge is low and extends for the length of the adductor field which may or may
not extend as far as the middle of the valve.

Prior to the present study Productorthis was only known outside of Europe
in South America, and Kozlowski has speculated on its absence from North
America. The interesting feature of the North American specimens is their large
size, which is about twice that of the usual European representatives. So far the
genus is known only from Virginia and Alabama where it is a rare fossil at all
its localities. Two specimens only are known from the Arline formation in the
form of a species resembling P. eminens (Pander) but much larger. The same
species is known from the Little Oak formation of Alabama and the Botetourt
formation of Virginia. The reefy masses of the Effna limestone in Virginia have
yielded interesting species of this genus which seem to be restricted to this pe-
culiar environment.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 335

PRODUCTORTHIS AGILERA (Willard)
Plate 56, B, figures 6-25

Nicolella agilera Wittarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 272,
pl. 3, fig. 7, 1928.

Shell large for the genus, slightly wider than long, with the width of the hinge
less than or greater than the width at the middle. Cardinal extremities in young
specimens acute but in adults or old individuals forming a right angle or obtuse.
Sides oblique to rounded and the anterior margin broadly rounded. Surface
marked by distant costellae, 3 to 6 in the space of 5 mm. at the front margin.
Lamellae numerous and closely crowded anteriorly.

Pedicle valve moderately convex in lateral profile with the most convexity in
the posterior half; anterior profile broadly convex, with long moderately steep
slopes. Umbonal and median regions full with steep umbonal slopes and mod-
erately steep lateral slopes. Anterior slope long, moderately steep. Beak in-
curved, beak and umbo protruding posterior to the posterior margin. Interior
with deep delthyrial cavity, thickened muscle platform with adductor track.
Diductor scars long and slender.

Brachial valve moderately convex with the front third somewhat flattened ;
anterior profile broadly and gently convex with the margins more or less re-
flected in a brachial direction. Median region swollen gently with gentle slopes
leading into shallow troughs produced by the margins which are deflected in the
direction of the brachial valve. Interior with ponderous cardinal process and
short, low median ridge. Adductor field small, rectangular.

Measurements in mm.—

Hinge
Length Width width Thickness
PROLOG A iste ois 6 i0/a 5-6 oat ee bets 17.5 18.7 21.9? 3.90
Hypotype (1o9890d) ............. 27.3 31.0+- 24.0+- 11.5
ie (brachial valve 1o9891a). 15.6 22.6 23.2 ?

Types—Holotype: M.C.Z. 8607; figured hypotypes: 1098goa-d, 1o9891a,f,g,
1og8g5a-c, 109896; unfigured hypotypes: 10g890e-h, I0g989ib-e, r1o9895d,
109899b-d ; figured specimen: 109899a.

Horizon and locality —Effna formation in Virginia: Porterfield Quarry, 5
miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle; McNutt
Quarry 12 miles southwest of Bland, Burkes Garden (15’) Quadrangle.

Discussion—tThis is the largest species of the genus known in either North
America or Europe and differs from its nearest relative P. americana in its
greater size, less swollen pedicle valve, less convex brachial valve, and stronger
ornamentation.

All the specimens from the Effna formation have been placed under this species
although considerable discrepancy in their size occurs. None of the specimens
taken from the hard limestone show the ornamentation in detail, but it seems
to be about the same as that of the material taken from the shaly beds on the
Porterfield reef. Most of the limestone specimens break out as a core leaving the

336 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

outer marginal frill in the rock. The inner core thus obtained differs somewhat
in proportions from the complete specimens.

PRODUCTORTHIS AMERICANA Cooper, new species
Plate 49, A, figures 1-4; plate 56, A, figures 1-5; plate 82, C, figure 12
Productorthis sp., Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 42, pl. 73, figs. 26-28, 1942.

Large for the genus, length and width nearly equal. Hinge slightly narrower
than the greatest width which is near the middle. Surface multicostellate and
imbricate ; costellae numbering about 15 in 10 mm. at the front of the holotype;
imbrications about I mm. apart.

Pedicle valve strongly convex in lateral profile but flattened in about the mid-
dle; strongly arched but medially flattened slightly in anterior profile. Median
and anterior region swollen; lateral slopes steep and concave. Umbo swollen;
beak incurved and almost touching the umbo of the brachial valve. Dental plates
thick ; apical callosity large, excavated where the pedicle was attached. Gingly-
moid joint deep.

Brachial valve moderately convex in profile, median sulcus defined at the umbo
but lost toward the front of the valve. Chilidium large, circular.

Measurements in mm.—

Hinge
Length Width width Thickness
Einictype 475.00stLw. Siiteed: B22 14.9 20.6 16.6 11.6
Paratype (brachial valve 116887).. 11.4 14.1 13.8 1.5

Types.—Holotype: 98184a; figured paratypes: 98184b, 116886b, 116887; un-
figured paratype: 116886a.

Horizon and locality—Arline formation in Virginia: Quarry on north side
of Marion, Marion (T.V.A. 218-SE) Quadrangle.

Botetourt formation in Virginia: North of Virginia Highway 114, 2.3 miles
west of Montgomery-Roanoke County line, 12 miles northeast of Blacksburg,
Montgomery County.

Little Oak formation in Alabama: From a road cut on U. S. Highway 31, 4
mile north of Pelham, Bessemer Iron District (15’) Quadrangle.

Discussion.—This species is characterized by its strongly convex valves. It
differs from P. agilera in its size and more closely crowded ornamentation as
well as the shape of the valves. This is a very rare species, only four specimens
having been found.

The two specimens found in Catawba Valley, Va., and the brachial valve from
the Little Oak limestone in Alabama are ornamented like the specimens from
Marion, Va. They are not, however, as convex as the holotype. It appears cer-
tain that the holotype has been somewhat shortened by compression on beak and
anterior margin, thus shortening and thickening the specimen.

Family HESPERONOMIIDAE Ulrich and Cooper, 1936
Transverse Orthacea with flattish or shallow valves, orthoid muscle field in the
pedicle valve, orthoid brachiophores, and a simple cardinal process. Pseudo-
deltidium unknown, but chilidial plates or chilidium present.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 337

Flattish orthoids are fairly common in the Table Head series and in boulders
of the Mystic conglomerate. It is likely that other species of Hesperonomiella
will be recognized among them.

Genus HESPERONOMIELLA Ulrich and Cooper, 1936

Hesperonomiella Utricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 622, 1936; Geol. Soc.
Amer. Special Pap. 13, p. 123, 1938.

HESPERONOMIELLA MINOR (Walcott)

Plate 121, H, figures 20-22

This is a poorly known genus and species. The interiors have hitherto been
known only from molds of the interior produced by burning off the shell. Re-
cently a few excellent interiors of both valves were obtained from L. F. Hintze.
These show the pedicle valve to have a shallow delthyrial cavity and probably
short, stout dental plates. These structures if present are concealed by shell de-
posited on the sides of the delthyrial cavity. The teeth are so large that they
seem to rest on the floor of the delthyrial cavity. Pallial marks are strongly
developed and consist of strong vascula media extending anterior of the diductor
scars and dividing at about two-thirds the distance from the beak. The brachial
valve has short and stout brachiophores much concealed by excess shell of the
notothyrial platform.

Hypotype.—117939.
Horizon and locality—Upper part of Pogonip group= Wahwah formation in
Utah: T. 22 S., R. 14 W., Confusion Range, Millard County.

HESPERONOMIELLA QUEBECENSIS Cooper, new species
Plate 172, D, figures 13-20

Shell of about the usual size for the genus, wider than long; cardinal extremi-
ties acute; hinge forming the widest part of the shell; lateral margins gently
rounded; anterior margin broadly rounded; surface multicostellate but orna-
mentation too poorly preserved to describe accurately.

Pedicle valve gently convex in lateral profile and broadly convex in anterior
profile. Umbo and median regions somewhat swollen; lateral slopes concave,
short, gentle; anterior slope short and gentle; delthyrial cavity narrow, triangu-
lar ; vascula media strongly developed.

Brachial valve very gently convex in lateral profile; nearly flat in anterior
profile; umbonal region gently swollen; sulcus shallow and broad, extending to
the anterior margin ; flanks on each side of sulcus gently swollen. Brachiophores
short ; median ridge low, short.

Measurements in mm.—

Hinge
Length Midwidth width Thickness
TANGEIDE ie dle safe 2c << 3 ae'se = sakes « 14.1 17.6 17.6-+ rey
Paratype (pedicle valve 116849d)... 14.6 17.8 21.0 17
% (brachial valve 116849b). 10.5 15.8 17.0 ?

338 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 116849a; figured paratypes: 116849b,d,f; unfigured para-
types : 116849¢,e.

Horizon and locality—Boulders in the Mystic conglomerate in Quebec, Can-
ada: Stanbridge Township, Range 6, Lot 21, 2.6 miles north and 4 mile east
of Mystic.

Discussion.—This species is characterized by its wide hinge and brachial valve
of low convexity. It differs from H. porcias (Walcott) in having a stronger cos-
tellation and less convex brachial valve. The delthyrial cavity of the Quebec
species is also much smaller than that of H. porcias.

Family ORTHIDIELLIDAE Ulrich and Cooper, 1936

Small Orthacea in which the simple cardinal process is cemented to the
brachiophores by deposits of shell substance.

Genus ORTHIDIELLA Ulrich and Cooper, 1936

Orthidiella ULricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 621, 1936; Geol. Soc. Amer.
Special Pap. 13, p. 108, 1938.

ORTHIDIELLA CARINATA Ulrich and Cooper
Orthidiella carinata ULRicH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 108, pl. 16A,
figs. I, 5, 6, 1938.
Type.—Holotype : 91206.
Horizon and locality—Same as for O. extensa, below.

ORTHIDIELLA COSTELLATA Cooper, new species
Plate 30, C, figures 12-19

Shell large for the genus, subquadrate in outline; hinge forming the widest
part; lateral margins very gently convex; anterior margin strongly convex ; car-
dinal extremities acute; surface marked by fine, rounded costellae that bifurcate
2 or 3 times but are not fasciculate; about 3 costellae to the millimeter.

Pedicle valve subcarinate medially but the carina becoming lost in the swollen
anterior region; lateral profile gently convex; anterior profile forming a broad
triangle, fairly sharp at the apex and with long gently sloping sides; umbonal
and lateral slopes long and gently concave. Pedicle interior with strong, thick
teeth; dental plates nearly obsolete; deep fossette located just below teeth;
delthyrial cavity deep and wide; diductor muscle scars long and slender, extend-
ing to points anterior to the middle; interarea apsacline; pseudodeltidium nar-
rowly arched, imperforate.

Brachial valve moderately convex in lateral profile; anterior profile bilobed,
the lobes low and indented by the median sulcus; umbo sulcate, sulcus continued
anteriorly to the front margin where it is fairly wide; areas bounding sulcus
gently swollen; posterolateral slopes gently convex. Brachial interior with
median ridge extending to the middle, low and rounded and separating deeply

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 339

impressed adductor field; brachiophores short and stout, supported by shell ma-
terial filling the notothyrial cavity ; cardinal process long and slender.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EAGUIGEYDG. ce iwicscicc Gus « 0.4 8.4 10.2 9.9 5.3
Paratype (116850c)... 7.8 7.0 8.9 9.0 3.9
$s (116850d)... 10.9 ? 12.1 12.9 2.4

Types.—Holotype: 116859a ; figured paratypes: 116859b-e; figured specimen :
117981a.

Horizon and locality—Orthidiella zone of the Pogonip group in Nevada: At
the Narrows, 2 miles up Whiterock Canyon, Roberts Mountains (1°) Quad-
rangle. Mottled zone 700 feet below the Eureka quartzite: Base of first ridge
east of Frenchman Flat, Las Vegas (1°) Quadrangle.

Discussion.—This species is very close to O. longwelli from southern Nevada
and agrees with it in many details. It differs, however, in the much finer orna-
mentation and the lack of any tendency for the costellae to bundle. The propor-
tions are slightly different, and the species tends toward a larger size than
O. longwelli.

ORTHIDIELLA EXTENSA Ulrich and Cooper
Plate 30, E, figures 21-32

Orthidiella extensa ULricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 1009, pl. 16C,
figs. 10, II, 15-17, 1938.

Types—Holotype: 91297; paratypes : 91297a,b; figured hypotypes : 116857a-c,
e-g; unfigured hypotype: 116857d.

Horizon and locality—Upper Pogonip group (mottled zone about 700 feet
below the Eureka quartzite) in Nevada: Near the base of the first ridge east of
Frenchman Flat, Las Vegas (1°) Quadrangle.

ORTHIDIELLA LONGWELLI Ulrich and Cooper
Plate 30, D, figure 20
Orthidiella longwelli ULricnH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 109, pl. 17D,
figs. 15-33, 1938.
O. striata ULricH and Cooper, Idem, p. 110, pl. 16B, figs. 2-4, 7-9, 1938.

Examination of large suites of this species shows that O. striata and O. long-
welli are in reality the same. Inasmuch as O. longwelli is the genotype the other
species is here suppressed.

Orthidiella longwelli shows considerable variation in the costellation, outline,
and profiles. One example is fairly coarsely costellate, has narrow ears and is
very robust in the umbonal region. The latter feature comes about by swelling
in young stages and a rapid contraction near the middle of the valve.

Types.—Holotype: 91299 ; paratypes : 91300a-g ; holotype of O. striata: 91303 ;
paratypes O. striata: 91304a,b.

Horizon and locality—Pogonip group (mottled zone 700 feet below the Eureka

340 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

quartzite) in Nevada: At the base of first ridge east of Frenchman Flat, Las
Vegas (1°) Quadrangle; at the Narrows 2 miles up Whiterock Canyon, Roberts
Mountains (1°) Quadrangle.

ORTHIDIELLA sp. 1
Plate 30, B, figures 6-11

This species is represented by only two specimens, a complete one and a
brachial valve. The cardinal extremities are produced into small ears. The
valves are moderately convex with the brachial valve somewhat transversely
narrowly humped in the median region. At the front margin the costellae form
fascicles of 2 or 3 costellae.

Measuremenis in mm.—t116861a, length 7.0, brachial length 6.3, midwidth
7.8, hinge width 7.1, thickness 3.9.

Figured specimens.—116861a,b.

Horizon and locality—Pogonip group (mottled zone 700 feet below the
Eureka quartzite), in Nevada: Base of first ridge east of Frenchman Flat, Las
Vegas (1°) Quadrangle.

Genus ORTHIDIUM Hall and Clarke, 1892

Orthidium Hatt and CLarKe, Pal. New York, vol. 8, pt. 1, p. 244, 1892—-ULricH and
Cooper, Geol. Soc. Amer. Special Pap. 13, p. 110, 1938.

ORTHIDIUM BELLULUM Ulrich and Cooper
Plate 30, A, figures 1-5
Orthidium bellulum Utricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 111, pl. 16F,
figs. 19-26, 1938.
Types.—Holotype: 92848 ; paratypes : 92846a-c.
Horizon and locality—Upper Pogonip group in Nevada: In Ikes Canyon on
the east side of the Toquima Range, Roberts Mountains (1°) Quadrangle.

ORTHIDIUM FIMBRIATUM Cooper, new species
Plate 31, A, figures 1-6

Shell small, resembling Orthidium bellulum; slightly wider than long; hinge
narrower than the greatest shell width near the middle; sides gently rounded;
cardinal extremities obtuse; anterior margin narrowly emarginate; valves un-
equally convex, the pedicle valve having the greater convexity; surface costel-
late and fimbriate; costellae about 4 to the millimeter at the front margin;
lamellae about 2 to the millimeter ; frill of a specimen about 2 mm. long meas-
uring I mm.

Pedicle valve deep and strongly convex in lateral profile; greatest convexity
in about the middle; anterior profile strongly convex and with a narrowly
rounded summit creased by the narrow sulcus; lateral slopes flat, short, and
steep; sulcus narrow, moderately deep and extending from the beak to the an-
terior margin. Median region swollen to form an ill-defined fold; umbo narrow,

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 341

swollen and protruding posterior to the hinge; interarea curved, approximately
orthocline.

Brachial valve having about half the depth of the pedicle valve, gently convex
in lateral profile and with greatest convexity in the umbonal region; anterior
profile broadly convex with short and moderately steep slopes and with the
median region narrowly depressed by the sulcus. Beak small, protruding slightly
posterior to the posterior margin ; sulcus originating at the beak and extending
to the anterior margin and widening anteriorly ; anterior margin with a more or
less marked reentrant where the brachial and pedicle valve sulci meet; areas
bounding sulcus moderately swollen; posterolateral extremities concave and with
short, steep slopes.

Interior not known.

Measurements in mm.—

Brachial Hinge Length
Length length width Width Thickness of frill
Btvalentyiicr ied) Ao sty <a eral ines wits eich 4.3 3.9 3.8 5.0 2.5 ?
Paratype (pedicle valve 116856b)... 5.7 ? rs 5.3 7 Be 2.6 0.7?
4 (brachial valve 116854a).. ? CIA 3.0 2.8 ? I.1

Types——Holotype: 116855a; figured paratypes: 116854a, 116856b; unfigured
paratypes: 116854b, 116855b,c, 116856a.

Horizon and locality—Table Head series in Newfoundland: 4 mile north of
Belle Burn; south side of Stearing Island, Cow Head; Table Point Cove.

Discussion—This species is similar to Orthidium bellulum Ulrich and Cooper
in its proportions and ornamentation but differs in the strong sulci on both valves
and the greater depth of the pedicle valve in the Newfoundland species.

ORTHIDIUM GEMMICULUM (Billings)

Orthis gemmicula Bituincs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 75, fig. 68 (adv.
sheets, 1862), 1865.

Orthidium gemmicula (Billings) Hatt and CrarkeE, Pal. New York, vol. 8, pt. 1, pp. 217, 244,
pl. 7A, figs. 22-25, 1892ULricH and Cooprr, Geol. Soc. Amer. Special Pap. 13, p. 112,
pl. 16G, figs. 27-35, 1938.
Hypotypes.—G.S.C. 9070,a,b,d.
Horizon and locality—Probably late Upper Canadian (limestone No. 2) or
younger, Lévis, Quebec, Canada.

Genus TREMATORTHIS Ulrich and Cooper, 1938

Tremorthis (sic) Utricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 112, 1938.
Trematorthis Coorer, Journ. Washington Acad. Sci., vol. 32, No. 8, p. 230, 1942.

TREMATORTHIS MASONI Ulrich and Cooper
Plate 20, A, figures I-15
Trematorthis masoni Utricn and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 113, pl. 57A,
figs. I-9, 13, 1938.
Types.—Lectotype: 95876c; paratypes: 95876a,b,d-i; figured hypotypes:
116863a,d-g; unfigured hypotypes: 116863b,c.

342 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality —Pogonip group (mottled zone 700 feet below the Eureka
quartzite) in Nevada: At the base of the first ridge east of Frenchman Flat, Las
Vegas (1°) Quadrangle.

TREMATORTHIS ROBUSTA Cooper, new species
Plate 29, C, figures 21-27

Shell subquadrate in outline with gently rounded sides and anterior margin;
biconvex with the pedicle valve having the greater depth; hinge narrower than
the shell width at the middle; surface costellate, 2 to 3 costellae in the space of
I mm. at the anterior margin.

Pedicle valve with long and strongly apsacline interarea; gently convex in
lateral profile; anterior profile strongly convex and with long, gently convex
slopes; umbo carinate, the narrow swelling extended anteriorly to the front
margin as an ill-defined fold. Pseudodeltidium narrowly arched, short and with
a minute foramen.

Pedicle interior with large, thick teeth; dental plates nearly obsolete but ap-
pearing as a ridge on the sides of the delthyrial cavity ; muscle area somewhat
thickened ; delthyrial cavity deep; vascula media subparallel.

Brachial valve marked medially by a broad and shallow sulcus extending from
the beak to the anterior margin ; areas bounding the sulcus gently convex; lateral
profile gently and evenly convex; anterior profile broadly sulcate; posterolateral
areas small, with a gentle slope.

Brachial interior with stout brachiophores, short median ridge and trilobed
cardinal process.

Measurements in mm.—Holotype, length 7.3, width 7.7, hinge width 6.6,
thickness 3.8.

Types.—Holotype: 116865a; figured paratype: 116865c; unfigured paratypes:
116865b,d.

Horizon and locality—Pogonip group (mottled zone 700 feet beneath the
Eureka quartzite) in Nevada: At the base of the first ridge east of Frenchman
Flat, Las Vegas (1°) Quadrangle.

Discussion.—This species differs from T. masom by its robust form and the
parallel arrangement of the vascula media in the pedicle valve.

TREMATORTHIS TENUIS Cooper, new species
Plate 29, B, figures 16-20

Shell large for the genus, somewhat quadrate in outline; hinge forming the
widest part; sides very gently convex ; cardinal extremities acute; anterior mar-
gin strongly rounded. Surface fascicostellate, costellae forming bundles of 3.

Pedicle valve subcarinate, a median costella the strongest on the valve origi-
nating at the beak and extending to the anterior margin; gently convex in lateral
profile but having a greater depth than the brachial valve ; anterior profile form-
ing a low triangle with gently sloping lateral areas; beak small; interarea apsac-
line. Pseudodeltidium narrowly arched, foramen minute.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 343

Brachial valve very gently convex in lateral profile; anterior profile deeply
indented medianly and with lateral areas gently swollen ; umbonal region sulcate,
sulcus widening and deepening to the anterior margin where it is broad and
deep; areas bounding sulcus forming low plications; posterolateral areas small,
gently concave. Cardinal process a thin, delicate blade.

Measurements in mm.—Holotype, length 7.0, width 8.6, hinge width 9.6, thick-
ness 2.8.

Types.—Holotype: 117978a; unfigured paratype: 117978b.

Horizon and locality—Pogonip group (mottled zone 700 feet below the
Eureka quartzite) in Nevada: At the base of the first ridge east of Frenchman
Flat, Las Vegas (1°) Quadrangle.

Discussion—This species suggests Orthidiella extensa in its slender profile
and deeply sulcate brachial valve; it differs from Orthidiella carinata in its profile
and the deep sulcation of the brachial valve. It differs from Trematorthis mason
in being large, more strongly costellate, in having a minute foramen and in hav-
ing a deeper sulcus. The species suggests Orthidiella, but that genus has no
apical foramen. It is a more slender shell than T. robusta.

Family HESPERORTHIDAE Cooper, new family

Progressive Orthacea having long and wide palintropes, subreniform ovarian
impressions, and subparallel vascula media. Brachiophores long and more ad-
vanced than in the Orthinae. Remnants of a pseudodeltidium and achilidium are
retained in some genera. Delthyrium also margined by lateral plates in some
genera.

This family is erected for the Orthacea with long, slender brachiophores which
are commonly triangular in cross section. These contrast strongly with the
short brachiophores of the Orthinae. Another feature of interest is the presence
of a small pseudodeltidium which arches under the sides of the delthyrium at
the apex of the shell. This is partially covered, in some specimens, by lateral
plates that extend over the delthyrial edge.

Subfamily HesprrorTHINAE Schuchert and Cooper, 1931

Hesperorthidae with strong radial ornamentation on the exterior and without
concentric lamellae.

Genus HESPERORTHIS Schuchert and Cooper, 1931

Hesperorthis ScHucuert and Cooper, Amer. Journ. Sci., 5th ser., vol. 22, p. 244, 1931; Mem.
Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 85, 1932.

Hesperorthis is distinguished from Orthambonites, to which it has great re-
semblance, by certain external and internal features. On the outside Hesperorthis
always has strongly unequal valves, the pedicle valve is always the deeper but
the brachial valve is more often gently concave, more rarely slightly convex.
The palintrope of the pedicle valve is always fairly long and is usually curved.

344 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Orthambonites on the other hand always has both valves convex although the
pedicle valve is usually the deeper of the two. The palintrope of Orthambonites
is generally short and strongly curved, often so strongly curved as to simulate
the orthocline position.

The later members of Hesperorthis are generally provided with a pseudo-
deltidium. Usually this structure in the Ordovician members is located at the
apex and covers but a small portion of the delthyrium. This pseudodeltidium
is usually flat in profile and depressed slightly below the margins of the del-
thyrium. In the earlier members of the genus the pseudodeltidium is lacking or
has not been observed. In these shells identification with Hesperorthis is based
on other internal details.

Inside the pedicle valve of Hesperorthis the teeth are always small with small
oblique fossettes ; the dental plates are short and of the receding type. The muscle
area is usually cordate in outline, and the vascula media are like those of Ortham-
bonites and Orthis.

Inside the brachial valve the notothyrial platform is always well developed
and thickened. The brachiophores are elongate and usually triangular in sec-
tion and in this respect differ from Orthis and Orthambonites. The cardinal
process is usually thickened at its base and often bears a narrow longitudinal
furrow on the exposed face of the shaft.

Hesperorthis, but without a pseudodeltidium, appears first in the middle por-
tion of the Marmor, becomes abundant (with pseudodeltidium) in the late Mid-
dle Ordovician, reaches its climax in the Richmond with a new gigantic species,
and then declines into the Middle Silurian.

HESPERORTHIS ANTELOPENSIS Cooper, new species
Plate 269, C, figures 11-17

Shell of about average size for the genus, subpentagonal in outline ; length and
width about equal; side nearly straight, hinge width and midwidth nearly equal ;
anterior margin narrowly rounded; anterior commissure faintly sulcate; costae
rounded, numbering 32, and with 1 or 2 fine radial lines occupying the inter-
spaces.

Pedicle valve moderately convex in lateral profile, with the maximum con-
vexity just anterior to the beak; anterior profile strongly domed, the median
region narrowly convex and forming an indistinct fold; lateral slopes steep ; ears
small, approximately a right angle. Interarea long and with a long, narrow del-
thyrium. Pseudodeltidium small. Beak small and incurved.

Brachial valve gently concave in lateral profile, somewhat more strongly con-
cave in anterior profile; greatest concavity near the middle and extended an-
teriorly to the anterior margin as a poorly defined sulcus. Flanks bounding sul-
cus flat ; posterolateral extremities gently deflected toward the pedicle valve.

Measurements in mm.—Holotype, length 16.3, length of brachial valve 13.0,
midwidth 16.3, hinge width 16.6, thickness 8.3, height 8.7.

Type.—Holotype: 124232.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 345

Horizon and locality—Dark shales below the Eureka quartzite in Nevada:
Below two knobs of Eureka quartzite, north side of canyon 3.1 miles N. 32° E.
of Blair (Segura) Ranch, Antelope Mountains, Roberts Mountains (1°) Quad-
rangle.

Discussion.—This species is characterized by its straight sides, long interarea,
deep pedicle valve, and strongly incurved beak. It is most like H. colei, but
differs in having a longer and more curved interarea, deeper and more carinate
pedicle valve, and a more broadly sulcate brachial valve. Hesperorthis virginica
is not so deep as H. antelopensis, its interarea is more strongly apsacline, and
its brachial valve is less sulcate. Hesperothis sulcata of Oklahoma in not so deep
as the Nevada species, and its brachial valve is more deeply sulcate, so much so
that the anterior commissure is definitely and strongly sulcate.

HESPERORTHIS AUSTRALIS Cooper, new species
Plate 49, C, figures 11-15; plate 53, A, figures 1-31

Shell of medium size to small for the genus, slightly wider than long with the
hinge forming the widest part or usually slightly narrower. Maximum shell
width often just anterior to the hinge. Cardinal extremities varying from slightly
obtuse to slightly acute. Lateral margins nearly straight and slightly oblique to
very gently rounded. Anterior margin broadly rounded; the outline semiellip-
tical. Surface costate, costae direct, narrowly rounded, and numbering 26 to 30.
Interspaces occupied by several fine costellae, one of which may be stronger than
the others, and by fine concentric fila. Costae seldom intercalated.

Pedicle valve with lateral profile unequally convex and with the anterior flat-
tened ; maximum convexity located just anterior to umbo. Anterior profile sub-
carinate with the sloping sides forming an angle slightly less than 110°. Umbonal
region somewhat swollen with the swollen portion extending to the front margin
as a low fold. Lateral slopes long and fairly steep. Anterior slope long but less
steep than the lateral ones. Beak slightly incurved and forming an angle of
about 130° to 140°. Interarea strongly apsacline, slightly curved. Delthyrium
long and narrow ; pseudodeltidium small.

Brachial valve with lateral profile varying from very slightly concave to dis-
tinctly but slightly convex ; anterior profile the same. Median sulcus originating
at the umbo, expanding rapidly anteriorly to more than half the width; flanks
bounding sulcus very slightly convex; posterolateral extremities nearly flat.
Interarea short.

Pedicle interior with deep, elongate delthyrial cavity bounded by strong reced-
ing dental plates. Teeth small with deep fossettes. Vascula media not strongly
developed. Brachial interior with long brachiophores and stout cardinal process
often supplemented by lateral bosses. Median ridge low and stout, reaching
anterior to the middle.

346 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
Eloloty pe Cl RS Ue ED EG AS RES 13.4 my 15.3 14.4 5.8
Banatype TOES) |. a3 sis dw sceicsnid oe = 12.8 10.6 14.4 13.0 5.9
- (pedicle valve I116912a)... 19.9 ? 21.8 19.6 7.0
% (brachial valve 116912c).. ? 15.1 20.9 18.5 28
Uy (EIGOOEAN oe ce see eee 9.6 7.8 10.5 10.4 5.3
zs (pedicle valve 109906b)... 12.0 P 12.6 11.4 4.7
ce (brachial valve 109906a).. ? 10.6 13.3 12.4 1.4
n (THOOTAN pepe 20s ads cata 15.2 12.5 15.9 13.1 8.4?

Types—Holotype: 1099274; figured paratypes: 71965b, 109906c,g-i, 109927D,
109928a,f, 116909a-d, 116912a-c, 116914; unfigured paratypes: 71965a, 10ggO6a,
b,d-f,j-l, 109927c-1, 109928b-e,g.

Horizon and locality——Ridley (?) formation in Georgia: On U. S. High-
way 27, I mile north of Rock Spring, Nickajack (T.V.A. 113-SW) Quadrangle.

Wardell formation and Wardell part of Dryden formation in Tennessee: 0.3
mile southwest of Little Barren Church on old Tennessee Highway 33, Powder
Springs (T.V.A. 154-SW) Quadrangle; south of side road 1 mile northeast of
Watergap south of Bray, Swan Island (T.V.A. 162-NE) Quadrangle; Evans
Ferry section (Hesperorthis bed) on Tennessee Highway 25E, 4 mile northeast
of Indian Creek, Howard Quarter (T.V.A. 162-NW) Quadrangle; Clinch
River, 12 miles northeast of Liberty Hill probably in Howard Quarter (T.V.A.
162-NW) Quadrangle=Evans Ferry section; quarry 4 mile northeast of the
depot at Clinton, Clinton (T.V.A. 137-SW) Quadrangle, Jacksboro, Jacksboro
(T.V.A. 136-SW) Quadrangle; north of the Canyon of Gap Creek, 14 miles
west of Arthur, Cumberland Gap (T.V.A. 153-SW) Quadrangle.

Ridley formation in Tennessee on the east side of Marshall Knobs, 5 miles
south of Murfreesboro, Murfreesboro (15’) Quadrangle ; 0.6 mile south of Chap-
pel Hill Methodist Church on Tennessee Highway 28, 1 mile south of its junc-
tion with Tennessee Highway 8, Sequatchie County, Daus (T.V.A. 104-SW)
Quadrangle.

Wardell formation and Wardell part of Dryden formation in Virginia: North
quarry on Station Creek, 4 mile south of U. S. Highway 58, 2 miles east of Cum-
berland Gap, Wheeler (T.V.A. 153-SW) Quadrangle; Lloyd Carter’s barn, 0.8
mile by road northeast of brick school at Rye Cove, Clinchport (T.V.A. 188-
NW) Quadrangle.

Discussion.—This species is characterized by its nearly flat brachial valve,
fairly convex pedicle valve and the inconspicuous brachial sulcus. It approaches
H. tricenaria in size, especially the large specimens occurring at Station Creek
near Cumberland Gap in southwestern Virginia. Generally the species is some-
what smaller with a somewhat subcircular outline.

HESPERORTHIS BICONVEXA Cooper, new species
Plate 51, A, figures 1-6

Shell large for the genus, one-sixth wider than long with slightly obtuse cardi-
nal extremities. Sides gently rounded; anterior margin broadly rounded. Sur-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 347

face costate, costae numbering about 34 in an adult. Costae not greatly elevated,
somewhat narrowly rounded and separated by spaces equal in width to the
costae. Interspaces finely costellate.

Pedicle valve gently convex in lateral profile with the greatest convexity lo-
cated in the posterior half; anterior half somewhat flattened. Anterior profile
broadly convex. Median region swollen to form an indistinct fold. Lateral slopes
slightly convex, not steep. Cardinal extremities somewhat flattened. Interarea
moderately long, strongly apsacline.

Brachial valve moderately convex in lateral profile; anterior profile broadly
convex with short lateral slopes and a median depression. Median sulcus origi-
nating at the umbo, narrow, shallow, and extending for about three-quarters the
length where the valve is swollen slightly. Flanks broad and somewhat swollen
with short, gentle lateral slopes. Cardinal extremities somewhat flattened. Inter-
area short, anacline.

Measurements in mm.—Holotype, length 17.1, brachial length 16.3, width 21.5,
hinge width 20.0, thickness 8.6.

Types.—Holotype: 109962; figured paratype: 109964.

Horizon and locality —Lincolnshire formation in Tennessee: 4 mile northwest
of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle.

Discussion—This is a large species than can be recognized by its strongly
apsacline pedicle palintrope, a brachial valve that is unusually convex for the
genus, and by the large number of costae. Its nearest related form is H. longi-
rostris, but this differs in the greater length of the pedicle palintrope, the con-
cave to flat brachial valve, less numerous costae, and different outline in the adult.

HESPERORTHIS COLEI Cooper, new species
Plate 54, D, figures 16-21

Shell of about medium size for the genus, length and width about equal ; cardi-
nal extremities slightly obtuse or about a right angle; sides nearly straight ; an-
terolateral areas gently rounded; anterior margin fairly strongly rounded;
anterior commissure slightly sulcate; surface marked by 32 to 33 somewhat
broadly rounded costae separated by spaces narrower than the costae. Strong
concentric fila and fine radial lines occupy the striae.

Pedicle valve moderately convex with the greatest convexity in the posterior
third; anterior two-thirds moderately steep and gently convex; anterior profile
somewhat narrowly convex and with flat, steep slopes to the margins. Umbo
narrowly swollen, median region gently inflated; anterior slope long; postero-
lateral slopes steep. Interarea long, strongly curved, strongly apsacline. Interior
with large teeth, deep fossettes ; dental plates short and receding ; delthyrial cavity
deep ; muscle region somewhat elongated, somewhat thickened. Pseudodeltidium
exceptionally long for the genus; lateral plates well developed, marked by an
elevated ridge on each side of the delthyrium.

Brachial valve unevenly concave in lateral profile, the greatest concavity lo-
cated in the posterior third, the anterior two-thirds flat to gently concave ; umbo
concave; sulcus shallow, originating at the umbo, widening anteriorly and form-

348 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ing a moderately deep depression in the median and anteromedian regions.
Flanks bounding sulcus flat ; posterolateral regions deflected slightly toward the
pedicle valve; chilidium well developed, short; cardinal process stout; brachio-
phores stout, moderately long; median ridge low and long.

Measurements in mm.—Holotype, length 14.3, brachial length 11.4, width 14.9,
hinge width 14.6, thickness 6.9.

Type.—Holotype: 48796.

Horizon and locality—Decorah formation (Ion member) in Goodhue County,
Minnesota: 8 miles south of Cannon Falls; in a road cut on the county highway
1.1 miles east of U. S. Highway 52 on the south edge of Cannon Falls; Wagner
Hill, U. S. Highway 52, 5 miles south of Cannon Falls.

Same formation and member in Iowa: Along the Dugway, 4 mile west of
Decorah.

Discussion.—This species is characterized by having the length and width
almost equal, a long interarea, and somewhat crowded costae. The species is also
characterized by the unusual development of the pseudodeltidium and chilidium.
In most species of Hesperorthis the pseudodeltidium, when present, is short and
located at the posterior end of the delthyrium. In this species a pseudodeltidium
measuring 4 mm, in length in a delthyrium 6.5 mm. in length has been observed.
Furthermore, the pseudodeltidium is often considerably thickened and in at least
three cases is swollen above the level of the interarea. A chilidium is an unusual
feature in this genus, but most of the specimens of this species examined possess
it. The chilidium, however, is generally short but is well arched.

Another feature of interest is the low ridge along the margin of the lateral
plates bounding the delthyrium. The species differs from H. tricenaria (Conrad)
in the excessive development of the pseudodeltidium, smaller size, more concave
brachial valve, and more strongly apsacline interarea on the pedicle valve.

HESPERORTHIS CONCAVA Cooper, new species
Plate 51, E, figures 21-26; plate 54, C, figures I1-15

Shell of medium size for the genus, length and width about equal ; cardinal ex-
tremities approximately a right angle or slightly obtuse; sides gently rounded ;
anterior margin narrowly rounded; anterior commissure rectimarginate; sur-
face marked by about 30 narrowly rounded, strong costae separated by spaces
slightly narrower than the costae. Fine costellae mark troughs of the striae.

Pedicle valve strongly convex in lateral profile with the maximum convexity
slightly posterior to the middle; anterior profile strongly but broadly convex and
without the median narrowing characteristic of many species of this genus;
lateral slopes gently convex, steep; beak somewhat elongated, obtuse, forming
an angle of about 130°; median region strongly swollen with steep anterior,
lateral, and posterolateral slopes. Fold formed by an elevated median costa ex-
tending from beak to anterior margin but most prominent in anterior two-thirds.
Interarea long, fairly strongly curved, strongly apsacline; pseudodeltidium
short.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 349

Brachial valve fairly strongly concave in lateral profile with the deepest part
slightly posterior to the middle; umbo gently concave, narrowly sulcate; sulcus
narrow, expanding gradually anteriorly but never attaining much width; sulcus
extending directly to the anterior margin and containing 2 costae; areas bound-
ing sulcus nearly flat; posterolateral areas gently concave. Interior with long
brachiophores and long, low, median ridge.

Measurements in mm.—Holotype, length 14.8, brachial length 12.5, width
16.2, hinge width 14.8, thickness, 7.0.

Types.—Holotype: 83842; figured paratype: 116917.

Horizon and locality.—Platteville formation (McGregor member) in Wiscon-
sin: From a quarry on the south side of Ellenboro Hill halfway between Lan-
caster and Platteville; quarry on Wisconsin Highway 81, 1 mile northwest of
Ellenboro; on road 3 miles northwest of Platteville; Lancaster (30’) Quad-
rangle.

Platteville formation in Illinois: 14 miles northeast of Dixon.

Chaumont formation in New York: Loose in the bed of Black River, just be-
low the dam at the head of the island, Watertown, Watertown (15’) Quadrangle.

Discussion—This species is characterized by its strongly inflated pedicle valve
which is not subcarinate as is usual in many species of Hesperorthis, by the fairly
strongly concave brachial valve with its narrow sulcus, and by the peculiar nar-
row fold produced by the slightly elevated median rib. These features distinguish
it from H. australis and from H. colei, which is more finely costate and not so
strongly convex.

HESPERORTHIS ? COSTALIS (Hall)
Plate 32, E, figures 9-15
Orthis costalis Hatt, Pal. New York, vol. 1, p. 20, pl. 4, fig. 4a, 1847—RayMonp, Ann.
Carnegie Mus., vol. 7, p. 235, pl. 35, fig. 4, 1911.—BassLer, U. S. Nat. Mus. Bull. 92,
p. 888, 1915.

Raymond fixed the type of this species on an imperfect specimen occurring on
a piece of dark limestone containing a fragment of a Strophomena. Raymond
claims that the specimen which is from Chazy, N. Y., could have come only from
Middle Chazy or Black River rocks, the only two formations having lithological
characters like the fragment containing these specimens. Raymond also concludes
that the specimen is closer to Hesperorthis tricenaria than to any other species
then described from the Chazyan. It is certain that the specimen is not like any
named Chazy form and that it has some of the characters of Hesperorthis such
as the musculature and the interarea. For the present the name will have to rest
on that specimen, and definition of its horizon and biological characters will have
to await discovery of additional material.

Types.—Holotype: A.M.N.H. 528; figured hypotypes: 116853b-e,j; un-
figured hypotypes: 116853a,f-i,k-m.

Horizon and locality—Day Point formation (upper “orthis” bed) in New
York: Quarry just north of Hotel Champlain, south of Cliff Haven, Plattsburg
(15’) Quadrangle.

350 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

HESPERORTHIS ? COSTELLATA Cooper, new species
Plate 82, A, figures 1-6

Shell of about the usual size for the genus, length and width about equal ; sides
gently rounded ; hinge about equal to the midwidth; anterior margin somewhat
narrowly rounded. Surface costellate, costellae intercalated in several genera-
tions, distinctly fasciculate in places at the front and numbering about 50. Stria
between costellae occupied by concentric fila.

Pedicle valve unevenly convex in lateral profile, the posterior third somewhat
flattened, the median third moderately convex but the anterior third again flat-
tened. Anterior profile narrowly convex in the median region but with long, steep
lateral slopes. Beak prominent; umbo narrowly convex, the narrow convexity
continued anteriorly to the front margin as a poorly defined fold. Interarea long,
slightly curved, and apsacline.

Brachial valve faintly convex in lateral profile and broadly but gently convex
in anterior profile; sulcus shallow, indistinct, originating at the umbo and ex-
tending to the anterior margin. Flanks bounding sulcus faintly convex ; postero-
lateral extremities deflected and flattened in the direction of the brachial valve.

Measurements in mm.—Holotype, length 12.0, brachial length 10.0, width 13.7,
hinge width 14.4, thickness 5.5.

Types.—Holotype: 116918.

Horizon and locality.—Botetourt formation in Virginia: On Virginia High-
way 114, 2.3 miles west of the Montgomery-Roanoke County line, 12 miles north-
east of Blacksburg, Montgomery County.

Discussion.—This species is characterized by its costellate surface and in this
respect is unlike all other species of Hesperorthis described herein. The generic
assignment is doubtful because interior details are unknown and the ornament
is not like that of the majority of species.

HESPERORTHIS CRINERENSIS Cooper, new species
Plate 52, B, figures 8-15

Small for the genus, wider than long with the hinge forming the widest part;
cardinal extremities forming a large acute angle; sides gently oblique; front mar-
gin strongly rounded; anterior commissure gently sulcate; surface marked by
26 narrowly rounded elevated costae separated by striae about equal in width
to the width of the costae. Striae occupied by several fine radial lines.

Pedicle valve very gently convex in lateral profile; anterior profile narrowly
rounded medianly and with long and steep lateral slopes ; umbo narrowly swollen,
the swelling continued anteriorly nearly to the anterior margin as a poorly de-
fined fold; interarea long, nearly catacline; delthyrium open.

Brachial valve gently convex in lateral and anterior profiles; umbo sulcate;
sulcus narrow, shallow, widening and deepening gradually anteriorly to the front
margin; flanks bounding sulcus gently swollen; posterolateral extremities de-
flected slightly toward the pedicle valve; interior with a short and stout median

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 351

ridge; cardinal process a thin septum; brachiophores stout; chilidium slightly
developed.

Measurements in mm.—Holotype, length 8.2, brachial length 7.8, width 10.0,
hinge width 11.5, thickness 5.1.

Types.—Holotype: 1100044 ; figured paratype: 110004b.

Horizon and locality—Bromide formation (Mountain Lake member-middle
zone 7 of Decker) in Oklahoma: Rock Crossing of Hickory Creek approxi-
mately center sec. 35, T. 5 S., R. 1 E., Criner Hills, Carter County.

Discussion—This species is readily distinguished from H. sulcata which is
much larger, very differently shaped, and differently ornamented.

HESPERORTHIS ? DECIPIENS (Phleger)
Orthis decipiens PuueceEr, Bull. S. California Acad. Sci., vol. 32, pt. 1, p. 17, pl. 1, fig. 2, 1933.

Horizon and locality—Barrel Spring formation in California: In Barrel
Spring Canyon, Inyo Mountains.

HESPERORTHIS DUBIA Cooper, new species
Plate 51, B, figures 7-13

Shell fairly large for the genus, slightly wider than long with the hinge form-
ing the widest part ; cardinal extremities slightly auriculate; sides gently rounded ;
anterior margin narrowly rounded ; anterior commissure rectimarginate ; surface
marked by about 34 elevated, narrowly rounded costae slightly wider than the
separating grooves ; 2 or 3 fine costellae occupying the striae.

Pedicle valve very gently but unevenly convex in lateral profile, the greatest
convexity in the posterior third or half; anterior half somewhat flattened ; an-
terior profile narrowly humped in the median region with long, flat, and mod-
erately steep slopes to the margins. Anterior slopes long and gently convex;
beak obtuse, forming an angle of 140° to 150°; umbo broadly swollen; median
region gently swollen ; interarea very slightly curved ; strongly apsacline ; pseudo-
deltidium absent.

Brachial valve almost flat in lateral profile but with anterior portion slightly
concave ; anterior profile nearly flat; umbonal region gently swollen; median re-
gion and most of anterior depressed into a broad and shallow sulcus the anterior
part of which is slightly elevated near the margin; flanks bounding sulcus gently
and somewhat narrowly swollen; posterolateral areas flattened and deflected
slightly toward the pedicle valve; interarea short.

Measurements in mm.—Holotype, length 15.4, brachial length 13.7, width 17.9,
hinge width 17.3, thickness 6.4.

Type.—Holotype: 116919.

Horizon and locality—Lower Sevier formation in Tennessee: + mile north-
east of Miser, Louisville (T.V.A. 138-SE) Quadrangle.

Discussion—This is a large and rare species approaching H. tricenaria in
size. It differs from that species in the lesser convexity of the pedicle valve,

352 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

nearly flat brachial valve, shorter pedicle interarea which is more steeply apsacline
than that of H. tricenaria and much less inflated pedicle valve.

This species is also suggestive of H. biconvexa but has a nearly flat brachial
valve rather than a gently convex one; the pedicle valve is less swollen in
H. biconvexa and the costae are somewhat more distantly spaced.

HESPERORTHIS IGNICULA (Raymond)
Plate 51, F, figures 27-34

Orthis disparalis Bitt1ncs, Canadian Nat. Geol., vol. 4, p. 440, figs. 20a,b, 1850.

Orthis ignicula RayMonp, Amer. Journ. Sci., ser. 4, vol. 20, p. 369, 1905; Ann. Carnegie Mus.,
vol. 7, No. 2, p. 236, figs. Io, II, IQII.

Hesperorthis ignicula (Raymond) TwENHOFEL and WuitINnc, Geol. Soc. Amer. Special
Pap. 11, p. 46, pl. 7, figs. 3-5, 1938.

This species is generally fairly small for the genus, but the outlines and profile
are typical. The ornamentation consists of high, narrowly rounded costae that
appear in 2 generations, one at the beak and the other slightly anterior to it.
Nevertheless, the costae are of about uniform size along the margins. The inter-
spaces show a single costella. No pseudodeltidium was seen at the apex of the
delthyrium and none was reported by Raymond. The cardinalia of the brachial
valve are like those of Hesperorthis. Thus the entire expression of this species,
internal and external, is that of Hesperorthis, and this is perhaps the earliest
species of the genus.

Types.—Lectotype: Carnegie Mus. 5453; paratype: Carnegie Mus. 5527;
figured hypotypes: 109925a,b.

Horizon and locahty.—Valcour formation in New York: Cystid Point, Val-
cour Island, Plattsburg (15’) Quadrangle; on New York Highway 22, about 1
mile southeast of Beekmantown, Rouses Point (15’) Quadrangle.

HESPERORTHIS LONGIROSTRIS Cooper, new species
Plate 52, A, figures 1-7

Hesperorthis cf. H. tricenaria (Conrad) Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 41,
pl. 73, figs. 11, 12, 15 (not figs. 13, 14—Dinorthis sp.), 1942.

Shell of about usual size for the genus, slightly wider than long; hinge slightly
narrower than the greatest shell width which is at about the middle. Cardinal
extremities varying from a right angle to slightly obtuse. Anterior commissure
rectimarginate to very slightly sulcate. Lateral margins varying from nearly
straight to very gently rounded; anterior margin fairly strongly rounded. Sur-
face costate, with 27 to 30 strongly rounded costae separated by interspaces
slightly narrower than the costae, fine radial costellae appearing in the inter-
spaces and on the costae but too indistinct to enumerate.

Pedicle valve with the greatest curvature in the posterior half; somewhat nar-
rowly rounded medially in anterior profile; beak pointed, forming an angle of
100° to 110°. Umbonal region narrowly rounded with steep umbonal slopes.
Median region moderately swollen with steep slopes to the anterior and lateral

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 353

margins. Interarea long, steeply apsacline, slightly curved. Pseudodeltidium
present but a mere vestige. Interior with short, receding dental plates; teeth
small; lateral plates narrow; vascula media convergent medially, not strongly
developed.

Brachial valve slightly convex in lateral profile but perceptibly convex in an-
terior profile. Sulcus originating at the umbo, widening rapidly anteriorly but
only slightly perceptible at the anterior margin. Flanks bounding the sulcus
slightly convex; cardinal extremities gently deflected toward the pedicle valve.
Interarea fairly long, anacline. Interior with stout median ridge, moderately
thickened notothyrial platform, and moderately long brachiophores.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Piolo ype He Hoya Pet ts CIO 10.7 14.4 13.8 7.5
Paratype (98180e) .......... 10.2 0.4 13.2 13.0 6.0
RIGO0SAd)) Eons nee 14.4 12.0? 16.7 15.1 6.5

Types.—Holotype: 98180a; figured paratypes: 116920e, 1099341; unfigured
paratypes: g8180b-e, 116920a-d,f, 109934a-h,j-t.

Horizon and locality——Whistle Creek formation in Virginia: 14 miles north-
west of Lexington on Whistle Creek and on U. S. Highway 60, 100 yards south-
east of Whistle Creek, Lexington (15’) Quadrangle; Virginia Highway 602, 54
miles S. 82° W. of Middlebrook, Augusta County.

Ellett formation in Virginia: Ellett and Lusters Gate, Blacksburg (15’) Quad-
rangle.

Lincolnshire formation in Tennessee: 4 mile northwest of Eidson, Kyles Ford
(T.V.A. 170-SE) Quadrangle; Evans Ferry. In Virginia: At Marcem Quarry,
2 miles west of Gate City, Gate City (T.V.A. 188-NE) Quadrangle.

Discussion.—This species resembles H. australis but generally in its adult state
is somewhat larger. The brachial valve is generally flat or convex, seldom con-
cave in the adult. The most distinguishing feature is the interarea of H. longi-
rostris which is much longer than that of H. australis. The greater length of
the interarea makes H. longirostris considerably thicker in the posterior half
than is the stratigraphically higher species.

Although the outline and profile of H. longirostris approach those of H. sulcata,
the two species may be distinguished by the more prominent sulcus of the latter
and the longer interarea of H. longirostris.

HESPERORTHIS MATUTINA Cooper, new species
Plate 54, A, figures 1-4

Shell of about medium size for the genus, wider than long, with nearly straight
lateral margins and cardinal extremities approximating a right angle. Front
margin broadly rounded. Surface marked by 25 to 27 elevated, rounded costae
separated by interspaces about half the width of the costae. Fine radial costellae
appearing indistinctly between the costae.

Pedicle lateral profile with greatest convexity in the posterior half; anterior

354 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

profile broadly convex. Umbonal region convex ; median portion of valve slightly
swollen. Anterior and lateral slopes gently convex, the lateral slopes the steeper.
Interarea strongly apsacline, nearly flat; delthyrium without a pseudodeltidium
as far as can be observed. Interior with short, receding dental plates; muscle
area as usual in the genus.

Brachial valve with posterior half very slightly convex but the anterior half
perceptibly concave; median region slightly depressed by a shallow and wide
sulcus originating at the umbo. Flanks bounding sulcus very slightly convex;
cardinal extremities slightly deflected toward the pedicle valve. Interarea short,
anacline. Interior with short but stout brachiophores which are triangular in sec-
tion because they have a keel along the outer face. Notothyrial platform not
greatly thickened; cardinal process slender but the thickened base bearing a
longitudinal slit.

Measurements in mm.—

Hinge

Length Width width

Holotype (pedicle valve).................. 12.5 15.5 15.2
Paratype (brachial valve 109975a)......... 9.7 12.0 13.5

Types.—Holotype: 109975b; figured paratypes: 109975a,c,e; unfigured para-
types: 109975d,f-1.

Horizon and locality—Tulip Creek formation in Oklahoma: West Spring
Creek, northeast corner sec. 1, T. 2 S., R. 2 W., 3 miles east of Pooleville ; along
an east-west road 2 miles southwest of Nebo, Murray County.

Discussion.—The closest relative of this species is H. ignicula (Raymond)
from the Valcour limestone of the Chazy group of New York. In the Oklahoma
species the costae are wider and separated by narrower striae, the pedicle beak
is less incurved, and the same valve is less convex; inside the brachial valve the
notothyrial platform is smaller and more thickened and the cardinal process
stouter.

HESPERORTHIS MULTICOSTATA Cooper, new species
Plate 51, C, figures 14-18

About medium size for the genus, slightly wider than long. Hinge about equal
in width to the midwidth of the valves. Lateral margins nearly straight; antero-
lateral margins gently curved; anterior margin somewhat narrowly rounded.
Anterior commissure gently sulcate. Apical angle 130°. Surface ornamented by
38 narrowly rounded costae separated by spaces narrower than the costae.

Pedicle valve unevenly convex in profile; the greatest convexity located near
the middle. Umbonal region flattened in lateral profile. Anterior profile nar-
rowly convex with the flanks forming an angle of 110°. Umbonal region sub-
carinate, the folding prominent at the middle but only slightly defined at the
front. Lateral slopes steep and flat. Interarea strongly apsacline, forming an
angle with the lateral commissure slightly more than a right angle; very slightly
curved. Beak slightly incurved.

Brachial valve gently convex in lateral profile; strongly indented medially in

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 355

anterior profile. Median sulcus deepest in the posterior half, becoming shallower
and wider anteriorly and occupying about one-fourth the width at the front.
Flanks bounding sulcus strongly folded for the genus. Posterolateral slopes
concave, gentle.

Measurements in mm.—Holotype, length 14.1, brachial length 12.0, width 15.7,
hinge width 14.0, thickness 6.8.

Types.—Holotype: 109986.

Horizon and locality——Lincolnshire formation in Tennessee: Evans Ferry,
U. S. Highway 25F, about 1 mile north of Indian Creek, Howard Quarter
(T.V.A. 162-NW) Quadrangle.

Discussion.—This species is distinguished by the numerous closely crowded
costae, the deep sulcus, and the strongly carinate pedicle valve. It is somewhat
similar to H. biconvexa but is more carinate, has a deeper sulcus and more
closely crowded costae.

HESPERORTHIS QUADRATA Cooper, new species
Plate 50, K, figures 47-54

Shell of about medium size for the genus, length and width about equal ; hinge
forming the greatest width; cardinal extremities slightly auriculate; sides nearly
straight ; anterior commissure sulcate; anterior margin narrowly rounded; sur-
face marked by 28 to 32 rounded costae separated by spaces narrower than the
costae.

Pedicle valve unevenly convex in lateral profile, the posterior half having the
greater convexity ; anterior profile narrowly convex and with steep lateral slopes.
Umbonal region swollen, the swelling continued anteriorly along the median
portion as a low fold; cardinal extremities not flattened but forming a part of the
steep and long umbonal slope. Interarea long, slightly curved, strongly apsacline.
Pseudodeltidium moderately long. Interior with short, receding dental plates.

Brachial valve gently concave in lateral and anterior profiles; umbo sulcate,
the sulcus deepening and widening anteriorly to the front margin where it is
moderately deep and somewhat V-shaped; 5 or 6 costae occupy the sulcus ; flanks
bounding sulcus flattened; posterolateral extremities very slightly deflected in
the direction of the pedicle valve. Interior with the usual features of the genus.

Measurements in mm.—Holotype, length 12.9, brachial length 10.0, width 12.7,
hinge width 13.3, thickness 6.4.

Type—Holotype: 116921.

Horizon and locality.—Lebanon formation in Tennessee: Cut on U. S. High-
way 241, 2.1 miles north of the Bedford-Rutherford County line in Rutherford
County ; Lebanon; cut and quarry on U. S. Highway 41, 12 miles southeast of
Murfreesboro ; south side of U. S. Highway 70S, 4 to $ mile east of Readyville ;
Columbia; south of Aspen Hill; Lavergne; near Prospect; Tennessee High-
way 16, 5.1 miles north-northwest of Shelbyville; 13 miles west of Spring City,
Sequatchie Valley ; Shelbyville; U. S. Highway 70S, 4 mile east of Rutherford-

350 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Cannon County line, Cannon County; U. S. Highway 7oN, opposite Fairview
Service Station, 4 mile west of Rome, Smith County.

Lebanon formation in Georgia: Beside the road 0.1 to 0.2 mile south of the
quarry, 13 miles south-southeast of Cove Church, 5 miles south of Chickamauga,
Kensington (T.V.A. 106-SE) Quadrangle.

Discussion.—This species is characterized by its parallel sides and small ears
and the deeply sulcate anterior commissure. In the latter respect it reminds one
of H. sulcata, but the commissure of the Lebanon form is deeper than that of the
Oklahoma species and the outline is very different. The Lebanon species is sug-
gestive of H. colei but has a deeper sulcus which reaches the anterior margin
whereas this feature of H. colei does not significantly affect the margin.

HESPERORTHIS SULCATA Cooper, new species
Plate 52, D, figures 22-37
Orthis tricenaria DECKER (not Conrad), Oklahoma Geol. Surv. Bull. 55, pl. 13, fig. F, 1931.

Shell of about medium size for the genus, length and width nearly equal in
the adult but with the width exceeding the length in the young. Hinge forming
the greatest shell width in young specimens but equal to or slightly less than
the greatest shell width in adults. Greatest shell width of adults variable, located
between hinge extremity and middle. Cardinal extremities slightly auriculate in
the young, nearly a right angle in adults. Lateral margins nearly straight or very
gently convex ; front margin broadly rounded. Anterior commissure varying from
strongly to gently sulcate. Valves ornamented by 28 to 30 broadly rounded to
subangular costae separated by striae narrower than the costae. One or more
fine radial lines occupying the striae between the costae, the line at the base of
the stria being the larger.

Pedicle valve moderately and evenly convex in lateral profile; broadly and
fairly strongly convex in anterior profile. Median region somewhat swollen from
umbo to anterior margin but well rounded and not subcarinate. Lateral slopes
long and steep; anterior slope long but not as steep as the lateral slopes. Inter-
area long, strongly apsacline, curved. Beak incurved; delthyrium long and nar-
row ; pseudodeltidium short. Teeth small, dental plates short and receding. Del-
thyrial cavity deep and narrow; muscle area small. Vascula media narrow,
deeply impressed.

Brachial valve gently concave in lateral profile and medially sulcate with flat-
tened flanks in anterior profile. Beak prominent, somewhat elevated. Interarea
moderately long, strongly anacline. Sulcus deep, originating at the beak and
widening to the anterior margin where it occupies about one-third the width.
Flanks bounding sulcus narrow, very gently convex; posterolateral areas flat-
tened; cardinal extremities deflected toward the pedicle valve. Interior with
shallow notothyrial cavity bounded by broad and long brachiophores. Median
ridge short and low. Sockets narrow, deep. Cardinal process not strongly
thickened.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 357

Measurements.—
Brachial Hinge
Length length Width width Thickness

folotypel, i sake sa.) 13.8 11.7 15.3 14.1 6.7
Basatype (109992d).. 13.5 10.9 14.0 12.4 6.0
(109994c).. 10.5 8.7 10.3 11.3 5.7

* (109994b).. 10.4 8.7 ht 11.8 5.0

a (109988a).. 14.3 11.4 14.7 14.4 6.9

8 (109987d).. 16.2 13.3 17/2 15.6 7.0

s (109987c).. 14.0 11.1 15.8 152 6.5

Types.—Holotype : 109987b ; figured paratypes : 109987a,d, 109992e, 109994b ;
unfigured paratypes: 109987c,e,f, rog9g88a-f, 10g992a-d, 10g994a,c-h, 116922.

Horizon and locality—Bromide formation (Pooleville member-O-ropflecia
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek, about center
sec. 35, [. 5 S., R. 1 E.; ona branch of Hickory Creek, NW+# sec. 26, T. 5 S.,
R. 1 E., Criner Hills, Carter County. Upper Bromide formation in Oklahoma:
Just west of the road on the Russell Ranch, SE# sec. 3, T. 2 S., R. 3 E., Murray
County.

Discussion.—This species is characterized by having its length and width
nearly equal, broad costae, and deep brachial sulcus. It is closest to H. australis
but differs in its more quadrate outline and the greater development of the
sulcus.

HESPERORTHIS TENUICOSTATA Cooper, new species
Plate 54, E, figures 22-40; plate 82, B, figures 7-11

Shell of about medium size for the genus, a little wider than long. Width of
hinge about equal to width of valve at middle or somewhat less. Lateral mar-
gins very slightly to moderately curved; front margin broadly rounded. Anterior
commissure slightly sulcate. Apical angle about 110°. Surface marked by about
29 direct, elevated, and narrowly rounded costae with interspaces about as wide
as the width of a costa.

Pedicle valve moderately convex with the greatest convexity in the posterior
half; anterior profile strongly convex. Median portion swollen; flanks gently
convex and moderately steep. Interarea gently curved, strongly apsacline. Beak
a little incurved. Interior with small elongate muscle area.

Brachial valve slightly convex in lateral profile; slightly indented medially in
anterior profile. Sulcus narrow, very shallow. Flanks bounding sulcus very
slightly swollen. Posterolateral extremities slightly depressed. Notothyrial cavity
shallow ; brachiophores long.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Halotypenink... 12) sis 10.8 9.1 THe 9.8 5.0
Paratype (109973a).. I1.5 9.5 12.5 10.6 5.9

Types.—Holotype: 116924; figured paratypes: 109970a, 109973a, 116923;
unfigured paratypes: 109970b-d, 109973b-e.

358 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality—Lenoir formation (ss.) in Tennessee: At Sweetwater,
Sweetwater (T.V.A. 131-SW) Quadrangle; quarry on north side U. S. High-
way 11, 4 mile south of Philadelphia, Philadelphia (T.V.A. 131-NW) Quad-
rangle. Shale streak in granular beds below Mosheim limestone: Behind Quaker
Church, north corner of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.
In Virginia: Along the road on North Fork, 3 miles south-southeast of North
Fork, Christiansburg (30’) Quadrangle.

Discussion.—This species suggests H. australis but differs in having a nar-
rower hinge, more convex pedicle valve, a more convex brachial valve, and more
curved palintrope. It differs from H. longirostra in having a shorter palintrope
and more rounded outline.

HESPERORTHIS TRICENARIA (Conrad)
Plate 52, C, figures 16-21; plate 54, B, figures 5-10

Orthis tricenaria Conrad, Proc. Acad. Nat. Sci. Philadelphia, vol. 1, p. 333, 1843.—BASSLER,
U. S. Nat. Mus. Bull. 92, p. 897, 1915.

Hesperorthis tricenaria (Conrad) ScHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist.,
vol. 4, pt. 1, p. 86, 1932.

Orthis disparilis CoNRAD, Proc. Acad. Nat. Sci. Philadelphia, vol. 1, p. 333, 1843.

Large for the genus; slightly wider than long; cardinal extremities slightly
obtuse or approximately a right angle, occasionally auriculate; sides nearly
straight to gently rounded; anterior margin broadly rounded; anterior com-
missure rectimarginate to faintly sulcate. Surface marked by 32 narrowly
rounded and elevated costae; interspaces marked by a single costella in the
trough.

Pedicle valve strongly and evenly convex in lateral profile; anterior profile
strongly convex with a tendency to subcarination in the median region; lateral
slopes long and steep. Beak erect and elongated ; umbo full; fold indistinct but
indicated by a single median costa more elevated than those surrounding it;
median region swollen; posterolateral slopes steep. Interarea long, slightly
curved, strongly apsacline ; pseudodeltidium small.

Brachial valve nearly flat to gently concave in lateral profile; anterior profile
gently concave ; umbo concave, marked by a shallow, narrow sulcus that extends
anterior to the front margin; sulcus inconspicuous ; flanks bounding sulcus flat
to slightly concave; cardinal extremities deflected slightly toward the pedicle
valve. Interarea long, strongly anacline.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (24752a).......... 19.6 15.7 21.2 20.3 9.3
i (S4G00) 22scRHNENK Os 20.1 15.9 22.3 Zoe 9.0
nk (:2099824:));... Haka iors 18.4 ? 21.0 20.7 6.9
nf G200082b).... 3.04 5..'« ? 15.9 21.2 20.5 2.4

Types—Holotype of Orthis disparilis: A.M.N.H. 911/1. Figured hypotypes
of H. tricenaria: 24752a, 109982a; measured hypotypes: 84000, 109982b.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 359

Horizon and locality—Decorah formation (Guttenberg member) in Wiscon-
sin: Mineral Point; 0.1 mile south of the Little Platte River on Wisconsin
Highway 81, 2 miles northwest of Platteville, Mineral Point (30’) Quadrangle;
3 miles northwest of Platteville, Lancaster (30’) Quadrangle.

Same formation in Illinois: At Rocton.

Lower Trenton limestone in New York: At Middleville.

Barnhart formation in Missouri: On the old road 1 mile northwest of Chicago
Summer Camp, NW4SW3 sec. 32, T. 37 N., R. 9 E., Weingarten (15’) Quad-
rangle ; at Koch Valley School on U. S. Highway 61, NE. cor. SW4SW3 sec.
6, T. 41 N., R. 7 E., 2 miles south of Barnhart, Kimmswick (15’) Quadrangle;
on U. S. Highway 61, 0.1 mile south of Salt River, north of New London, Ralls
County.

Auburn chert in Missouri: $ mile east of Auburn, Elsberry (15’) Quadrangle.

Rockland formation in Ottawa, Canada: At Paquette Rapids.

Curdsville formation in Kentucky and Tennessee.

Discussion.—This species is characterized by its large size, being one of the
largest members of the genus to occur in the Middle Ordovician. It is character-
ized, besides its size, by its nearly parallel sides, shallow, narrow sulcus, and
indistinct pedicle fold. Although the type specimen is lost, it is possible to
identify the species in the Middle Ordovician sequence of southwestern Wiscon-
sin by its reported large size. The horizon of this large form is the lower part
of the Guttenberg above the thin band of blue clay so conspicuous in this part of
Wisconsin. The species is also conspecific with the abundant large Hesperorthis
of the Curdsville in Kentucky and its equivalents in southwestern Virginia and
eastern Tennessee. The species is also abundant in the upper part of the Plattin
limestone group and the so-called Decorah of eastern Missouri.

Hesperorthis disparilis (Conrad) is a small species that has for some years
been placed in the synonymy of H. tricenaria. This seems to be the correct place
for the species because the type specimen appears to be a young form.

HESPERORTHIS VIRGINIENSIS Cooper
Plate 51, D, figures 19, 20; plate 82, G, figures 28-32

Shell of about medium size for the genus, length and width about equal ; cardi-
nal extremities approximately a right angle, hinge slightly narrower than the
greatest shell width at about the middle; anterior commissure gently sulcate;
sides nearly straight to slightly rounded; anterior margin strongly rounded ; sur-
face marked by 30 rounded costae.

Pedicle valve gently convex in lateral profile with the greatest convexity in
the posterior half ; anterior profile narrowly convex and with long, steep slopes ;
umbo narrowly swollen, the swelling occupying the median region from the
beak to the margin, forming a poorly defined fold ; lateral slopes steep. Interarea
strongly apsacline to nearly catacline.

Brachial valve almost plane in lateral profile; gently concave in anterior pro-
file; umbonal region sulcate, the sulcus deepening and widening anteriorly to

360 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the front margin where the sulcus occupies nearly half the width; sides bound-
ing sulcus nearly flat; posterolateral extremities deflected slightly toward the
pedicle valve.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
ETIGIGEY Pei? s.ctlegs sudiyes:< 13.9+ 12.0 14.8 13.9 6.6
Paratype (97508).... 15.9 13:2 16.5 14.2 7.0-+

Types.—Holotype: 116927a; figured paratype: 97598; unfigured paratype:
116927b.

Horizon and locality—Oranda formation in Virginia: 4 mile north-northwest
of Green Mount Church; Broadway (15’) Quadrangle.

Discussion—This species is characterized by its slender form, subcircular
outline and steeply apsacline pedicle interarea. It is less convex, more slender in
outline, and somewhat more circular in outline than H. australis to which it has
some resemblance.

HESPERORTHIS sp. 1
Plate 54, F, figure 41

Represented by two specimens from the Botetourt formation in Virginia ex-
posed at the junction of Virginia Highways 311 and 114, 4 mile southwest of
Catawba, Salem (15’) Quadrangle. One specimen is crushed but shows both
valves. The exterior is marked by about 25 narrowly rounded costae. The
brachial sulcus is narrow, shallow, and inconspicuous. Scarcely any trace of
folding is exhibited on the pedicle valve. The interarea is curved, apsacline, but
not strongly so.

The second specimen is a cast of the pedicle interior showing strong dental
plates but a small muscle field. The lack of marked folding sets this shell apart
from all others described herein, but the specimens are too poor for further
elaboration.

Figured specimen.—109972.

HESPERORTHIS sp. 2
Plate 50, C, figures 8-13

A very well preserved specimen of Hesperorthis was taken near the middle
of the Edinburg formation (Nidulites zone) in Virginia, along Tumbling Run
about 14 miles southwest of Strasburg, Strasburg (15’) Quadrangle. It closely
resembles the type specimen of H. disparilis now assigned to H. tricenaria, but
it differs from that species in details of the ornamentation, showing it to be a
different species. The specimen is probably the young of a Hesperorthis which
has not yet been seen in adult form.

Figured specimen.—1 16926.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 361

Subfamily GLyptorTHINAE Schuchert and Cooper, 1931

Specialized Hesperorthidae with interior characters similar to Hesperorthis
but with an imbricated external surface. Pseudodeltidium and chilidium usually
absent but small apical (pedicle?) plate present.

Genus GLYPTORTHIS Foerste, 1914

Glypthorthis Forrste, Bull. Sci. Lab., Denison Univ., vol. 17, p. 258, 1914..—-SCHUCHERT and
Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 89, 1932.

GLYPTORTHIS ALTA Cooper, new species
Plate 44, A, figures 1-5

Shell of moderate size for the genus, hemipyramidal in outline; biconvex;
valves of unequal depth. Cardinal extremities obtuse. Lateral margins gently
rounded ; front margin broadly rounded. Anterior commissure faintly uniplicate.
Surface multicostellate, with 8 costellae occupying a space of 5 mm. at the front.
Costellae increasing by intercalation.

Pedicle valve hemipyramidal; unequally convex in lateral profile, with the
umbonal region moderately convex, the midportion of the profile flat and the
anterior quarter gently convex. Lateral slopes steep. A narrow, shallow sulcus
extends from the umbo to the front margin where it forms a slight tongue. In-
terarea long, nearly flat, strongly apsacline. Delthyrium long and narrow. Den-
tal plates short, receding ; anterior margin of muscle field thickened.

Brachial valve moderately convex in both profiles, somewhat swollen and with
moderately steep lateral slopes. Sulcus present on umbo but obsolete toward
the front where a narrow fold is barely discernible. Interarea long, deeply con-
cave, orthocline in position. Cardinalia ponderous; median ridge slender.

Measurements in mm.—Holotype, length 11.0, brachial length 11.0, width
13.5, hinge width 11.5, thickness 10.0.

Type.—Holotype: 110008.

Horizon and locality—Kimmswick formation in Missouri: Goetz Quarry,
Jefferson County.

Discussion.—This species suggests G. obesa in its form and ornamentation,
but the interarea of the pedicle valve is much longer and more strongly inclined.
The specimen referred by Bradley (Contr. Walker Mus., Univ. Chicago, vol. 2,
No. 6, p. 227, pl. 23, figs. 13-15, 1930) to Clitambonites diversus may belong
to this species. No cardinal view of that specimen is given which would reveal
the presence or absence of a pseudodeltidium, but the profiles suggest this new
Glyptorthis.

GLYPTORTHIS ASSIMILIS Cooper, new species
Plate 45, C, figures 15-35; plate 40, F, figures 27-32

Shell of medium to large size for the genus, wider than long in the young but
with the length and width about equal in adults. Hinge forming the widest part
in the young, becoming narrower in large specimens. Valves subequal in depth,

362 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the pedicle valve having a slightly greater depth. Anterior commissure recti-
marginate to faintly sulcate. Surface marked by high, narrowly rounded to angu-
lar costellae, 6 in the space of 5 mm. at the front of a large valve. Imbrications
distant, about Io in 5 mm.

Pedicle valve moderately convex in lateral profile with the greatest convexity
just anterior to the flattened umbo. Anterior profile moderately convex. Mid-
region moderately inflated. Slopes to lateral margins fairly steep and flat; an-
terior slope long and steep. Interarea moderately long, only slightly curved,
strongly apsacline. Beak prominent, slightly incurved. Teeth small, dental plates
short, receding. Muscle field large, extending to middle of valve.

Brachial valve moderately convex in lateral profile with the greatest convexity
in the midregion. Anterior profile gently convex. Sulcus shallow, occupying a
little more than one-third the width at the front margin. Sulcus occupied by 2
costellae at the umbo which increase by intercalation to 6 or more at the anterior
margin. Second generation costellae intercalated on the inside of the primary 2;
next generation intercalated on the outside of the primary 2. Umbo gently con-
vex; interarea long, a little curved; beak only slightly incurved. Notothyrial
cavity small and shallow; brachiophores short; cardinal process thin; median
ridge low, extending anterior to middle.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype i eters Pasth ie AY 13.7 12.5 I52 14.1 8.2
Paratype |GP100728 )y o./.'u'ais «send Sle ee 11.7 10.8 12.6 9.6 7.6
= (pedicle valve 1100I2c)... 13.8 ? 14.2 10.2 4.3
ss (Ce Oe Ser aT TOOL) to. L985 ? 14.0 11.6 ?
a (brachial valve 110013f) .._? 12.8 15.4 13.8 ?
° CYWOTSay eos keees tose 5 11.0 13.9 11.8 ?

Types.——Holotype: 110013j; figured paratypes: 110012c, 110013b-d,f,g,
116928c,f-i; unfigured paratypes: 110012a,b,d-f, 110013a,e,h,i, 116928a,b,d,e.

Horizon and locality—Ridley formation (lower third) in Tennessee: At Mur-
freesboro ; east side Marshall Knobs, 5 miles south of Murfreesboro, Murfrees-
boro (15’) Quadrangle.

Discussion.—This species is characterized by the strong convexity of both
valves, lack of perceptible fold or sulcus on the pedicle valve, and the fairly deep
and prominent brachial sulcus. The latter feature is a variable one, but in gen-
eral the sulcus is deepest between the two primary median ribs but may be defined
on each side of them as well.

Glyptorthis assimilis is most like G. bellatula from the Chatham Hill formation
north of Marion, Va., but differs in having a more convex pedicle valve particu-
larly in the median and posterior parts, in having a prominent pedicle umbo and
beak, and a more strongly incurved beak. The pedicle muscle area of the Tennes-
see species is in general somewhat larger than that of G. bellatula. The brachial
valve of G. assimilis is less convex than that of G. bellatula, and the sulcus is
less prominent. The ornamentation of the two species is different, that of G. as-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 363

similis tending to have prominent differentiation of the primary and postprimary
elements, whereas in G. bellatula the costellae are less strongly differentiated.

GLYPTORTHIS BELLARUGOSA (Conrad)
Plate 48, C, figures 12-18
Orthis bellarugosa Conrad, Proc. Acad. Nat. Sci. Philadelphia, vol. 1, p. 333, 1843—Hatt,
Pal. New York, vol. 1, p. 118, pl. 32, fig. 3, 1847.—BaAsster, U. S. Nat. Mus. Bull. 92,
P. 591, 1915.

Conrad’s type lot consists of two specimens, one small complete one and a
larger pedicle valve. The latter preserves the interior well, but the external orna-
mentation is badly worn. In his description Conrad gives the length of the species
as “less than half an inch.” It is best then to select the smaller specimen as the
holotype even though the species attains a greater length than half an inch. The
type specimen may be characterized as follows:

Outline quadrate, with gently convex lateral margins but nearly straight an-
terior margin. Cardinal extremities slightly greater than a right angle; anterior
commissure rectimarginate ; valves nearly equal in depth, the pedicle valve hav-
ing a slightly greater depth; surface multicostellate with about 57 costellae ap-
pearing in 3 generations. Median costella of pedicle valve slightly larger than
surrounding ones and extending directly from beak to margin. Imbricating con-
centric ornamentation closely spaced, about 6 imbrications in 2 mm., forming
rounded, short, blunt spines open anteriorly and at their extremity.

Pedicle valve moderately convex in lateral profile with the greatest convexity
located slightly anterior to the umbo. Front third slightly flattened ; fold not well
defined but median costella elevated throughout its length, and at anterior third
a costella is intercalated on each side to form a median fascicle that serves as a
fold. Median region somewhat swollen; lateral slopes even and steep.

Brachial valve with sulcus originating at beak and extending to anterior mar-
gin, narrow and shallow throughout its length. Sulcus marked by implantation
of a costella on each side ; additional costellae implanted on inside and outside of
these 2 slightly posterior to the middle. Tertiary intercalation of costellae occur-
ring anteriorly and bringing total number in sulcus to 9. Flanks bounding sulcus
gently swollen; slopes to cardinal extremities gentle and low.

Measurements in mm.—Lectotype, length 11.0, brachial length 10.0, width
12.0, hinge width 9.5, thickness 5.7.

Types.—Lectotype: A.M.N.H. a; paratype: A.M.N.H. (not numbered).

Horizon and locality (of lectotype).—Decorah formation (Ion member ?) in
Wisconsin: At Mineral Point, Mineral Point (30’) Quadrangle.

Discussion.—The type specimen of G. bellarugosa is characterized by its quad-
rate outline and its fairly fine costellae. No other specimens in the National
Museum collections are quite like this one. For that reason it is difficult to
assign the correct part of the Decorah shale from which the species comes.
Glyptorthis bellarugosa suggests G. costellata from the Bromide formation

364 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

(Pooleville member) of Oklahoma, but it is squarer and the ornamentation is
finer. Furthermore, the sulcus of the Oklahoma species is wider and deeper than
that of the Wisconsin form.

GLYPTORTHIS BELLATULA Cooper, new species
Plate 47, A, figures 1-8

Shell of about medium size for the genus, length and width about equal; hinge
slightly narrower than the greatest shell width which is located slightly anterior
to the middle. Cardinal extremities obtuse ; lateral margins varying from nearly
straight to sloping anterolaterally ; anterior margin broadly rounded. Anterior
commissure rectimarginate. Surface marked by subangular, fairly broad cos-
tellae separated by spaces about equal in width to the width of the costellae. Pos-
terior half of shells marked chiefly by primary costellae, the secondary costellae
appearing in the front half, one in each primary stria. Lamellae strong, distant,
2 or 3 in a millimeter measured near the middle of the valve.

Pedicle valve with lateral profile gently convex and with the greatest convexity
located in the umbonal region; anterior profile broadly convex. Umbonal region
subcarinate becoming flattened anteriorly to merge in the general convexity of
the valve. Anterior slope long, moderately steep; lateral slopes convex, fairly
steep. Interarea long, strongly apsacline. Teeth small, with deep fossettes. Den-
tal plates short and receding ; muscular area not extending to the middle of the
valve, not greatly thickened. Vascula media distinct, short.

Brachial valve evenly convex in lateral profile and with the maximum con-
vexity at about the middle; anterior profile broadly convex, slightly depressed
medially. Umbonal region moderately convex; sulcus originating just anterior
to the posterior margin, narrow and shallow, extending to the anterior margin
or dissolving into the general convexity of the valve just posterior to the front
margin. Flanks moderately convex with moderately steep slopes to the cardinal
extremities but shorter and more gentle slopes to the anterolateral margins. In-
terarea short, anacline ; median ridge carinate, extending slightly anterior to the
middle. Brachiophores and cardinal process usual for the genus.

Measurements in mm.—

Hinge
Length Width width Thickness
Holotype (pedicle valve) ............ 123 13.7 11.9 4.3
Paratype (brachial valve r110015e).... 10.7 12.6 10.0 2.8
a (CET OOTS CY ete ciecait oelorent steers 8.9 TUF ? P

Types.—Holotype: 110015a; figured paratypes: 110015d-h; unfigured para-
types: 110015b,c.

Horizon and locality—Chatham Hill formation in Virginia: Route 113
(Marion-Chatham Hill road), 6 miles north of Marion, Chatham Hill (T.V.A.
218-NE) Quadrangle.

Discussion—See Glyptorthis assimilis.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 365

GLYPTORTHIS CONCINNULA Cooper, new species
Plate 43, F, figures 22-43

Small to medium-sized for the genus, wider than long, with the hinge form-
ing the greatest shell width or so narrowed as to be less than the width near
the middle. Lateral margins ranging from straight and sloping medianly to
gently convex; anterior margin straight or slightly curved. Surface multicostel-
late, the costellae elevated and subangular and separated by spaces as wide or
wider than the costellae. Three generations of costellae may be counted: a set
originating at the beaks, a secondary set, few in number, intercalated near the
middle and a ternary set appearing a short distance posterior to the margin.
From 6 to 9 costellae appear in 5 mm. at the front margin depending on the
amount of anterior intercalation. From 20 to 36 costellae may be counted on a
valve. About 3 imbricating lamellae in the space of 1 mm. near the middle.

Pedicle valve in lateral profile with maximum convexity in the posterior half;
in anterior profile broadly convex with moderately sloping sides. Umbo full, this
fullness extended for the median length as an indistinct fold. Lateral slopes long
but only moderately steep as most of the fullness is concentrated in the median
area. Beak slightly incurved ; interarea nearly flat, short. Delthyrium narrow.
Interior with short, thick dental plates ; moderately deep delthyrial cavity ; muscle
field heart-shaped with adductor field slightly elevated, large diductor impres-
sions but small adjustor scars.

Brachial valve most convex in the posterior half in lateral profile but broadly
and gently convex and with the median part sulcate in anterior profile. Sulcus
originating at the umbo, prominent, widening and deepening anteriorly, variable
in depth and width. Sulcus with 2 costellae on the umbo, bifurcating in a short
distance to produce 4, and this number augmented by intercalations of the ternary
set near the front margin. Flanks moderately convex with short but fairly steep
umbonal slopes and with lateral slopes becoming less steep anteriorly. Interarea
short. Interior of brachial valve with short, stout brachiophores, prominent
median ridge and large adductor field. The anterior adductor scars are each
divisible into 2 impressions; the posterior scars small. Pallial marks not well
preserved in either valve.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PAGIAV PE le cics Gas tye ess 7.5 6.2 8.4 yi 4.8
Paratype (110025a)..... 8.3 7.6 10.1 9.5 5.4
o (10026) eine eae WE 6.9 8.7 IP 4.6
A (T1603ED) sur a. 6.2 5.5 7.4 6.1 By
he (7100358). °.\.: 8.3 7.8 10.4 9.6 4.4
i (m100274)) Fa0. 7.60 6.8 8.0 72 5.2

Types.—Holotype: 116931a; figured paratypes: 110025a, 110027a,b,
110028a,b, 110034a,b,e,g, 110035a; unfigured paratypes: 110026, 110028c-e,
110034c,d,f; 116931b.

Horizon and locality—Little Oak formation in Alabama: 4 mile northeast of

366 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pelham, and 2 miles north of Pelham, Bessemer Iron District (15’) Quadrangle.
Intersection of the Bailey Gap road with the main Cahaba Valley road, SW4SW4
sec. 13, T. 19 S., R. 2 W., 1} miles northeast of Newhope Church, Vandiver
(15’) Quadrangle.

Basal Athens formation in Tennessee: Along the road 24 miles south-south-
east of Riceville, Calhoun (T.V.A. 125-SW) Quadrangle ; 600 feet S. 40° E. of
the railroad and highway crossing I mile northeast of the courthouse in Athens,
Athens (T.V.A. 125-NE) Quadrangle.

Arline formation in Tennessee: Knoxville; southeast edge of Friendsville,
Concord (T.V.A. 138-SW) Quadrangle.

Arline formation in Virginia: Porterfield Quarry, 5 miles east of Saltville,
Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion—This is a small variable species but the majority of specimens
are wider than long with moderately convex valves, a pedicle valve with con-
siderable fullness longitudinally in the median area and a fairly wide and deep
sulcus in the brachial valve. It is not quite like any other species described but
approaches G. sulcata from which it differs in its more rectangular outline,
smaller size, less elongated palintrope of the pedicle valve, and shallower brachial
valve.

GLYPTORTHIS COSTELLATA Cooper, new species
Plate 43, C, figure 8; plate 44, D, figures 20-37

Glyptorthis cf. bellarugosa SCHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4,
pt. I, pl. 6, fig. 12, 1932.

Shell of about medium size for the genus, subquadrate in outline, and with the
width slightly greater than the length. Cardinal extremities forming a right
angle. Lateral margin straight to gently curved; anterolateral margins rounded ;
anterior margin slightly rounded to straight. Valves nearly equal in convexity.
Anterior commissure rectimarginate to slightly sulcate. Surface covered by about
47 thin, angular to narrowly rounded costellae, of which about 9 or 10 occupy 5
mm. at the front. Imbrications distant at the posterior but becoming crowded
toward the front of the valves, 2 to 3 in I mm.

Pedicle valve only moderately convex in both profiles, having the greater con-
vexity a little posterior to the middle. Midregion inflated ; lateral slopes moder-
ately steep; anterior slope gentle. Interarea moderately long; slightly curved;
apsacline.

Brachial valve gently and evenly convex with the greatest convexity at about
the middle. Sulcus prominent, widening from the umbo to occupy more than
half the width at the front margin where as many as 13 costellae may occupy it.
Flanks bounding sulcus moderately swollen. Slopes to cardinal extremities gently
concave and moderately steep. Interarea moderately long; slightly apsacline.
Beak slightly incurved.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 367

Measurements in mm.—
Dorsal Hinge

Length length Width width Thickness
Holotypeils hess ae 12.1 11.4 13.8 Til. 6.2
Paratype (110045a).. 10.5 10.0 11.3 11.0 5.5
* (110040a).. 9.3 8.8 10.8 8.8 5.0
- (t10040b).. 8.1 8.0 9.6 8.5 4.5
(110059a).. 12.2 11.3 13.8 10.4 6.8
H (110059c).. 12.8 11.6 14.6 1277 7.0

Types.—Holotype: 110052a; figured paratypes: 110038a, 110040a,b, 110052b,
110059a,b; unfigured paratypes: 110038b-d, 110040c-d, I110045a, I10059¢.

Horizon and locality.—Bromide formation (Pooleville member-O-oplecia
gouldi zone) in Oklahoma: On a branch of Hickory Creek, NW} sec. 26, T.
5 Ss. R. 1 E,, east side of Criner Hills; Rock Crossing of Hickory Creek,
NELSW35 sec. 35, T. 5 S., R. 1 E.; Criner Hills, Carter County.

Discussion.—Specimens of this species from section 26 along a small branch
of Hickory Creek are exceptionally well preserved and show the lamellae to per-
fection. Where the lamellae cross the costellae, they are pinched into narrow
spinelike folds. Perfect young specimens are obtainable here and are generally
transverse.

Glyptorthis costellata is suggestive of G. sulcata in its quadrate outline, but
the valves are not so convex, the sulcus of the brachial valve is less wide and
shallower, the palintrope is not so elongated, and the lamellae are coarser.

GLYPTORTHIS CRENULATA Cooper, new species
Plate 44, C, figures 11-19

Shell of about medium size for the genus, wider than long with the maximum
width in the midregion; hinge narrower than the greatest shell width; cardinal
extremities obtuse; sides moderately rounded; anterior margin nearly straight ;
anterior commissure narrowly sulcate; surface multicostellate, costellae about 2
to the millimeter at the front margin ; imbrications distant, about 2 or 3 in I mm.

Pedicle valve gently convex in lateral profile and with the maximum convexity
in the umbonal region; anterior profile with narrowly convex median region and
long, flat, steep slopes to the margins. Umbonal region narrowly convex, the
convexity carried to the median region where the surface becomes flattened.
Median costella more elevated and stronger than those surrounding it, defining
an indistinct fold.

Pedicle interior with short, receding, and flaring dental plates; muscle area
deeply impressed, extending a short distance anterior to the delthyrial cavity.
Vascula media and reniform ovarian impressions not strongly impressed.

Brachial valve evenly and gently convex in lateral profile with the greatest
convexity at about the middle; anterior profile broadly convex, indented medianly
by the sulcus; flanks bounding sulcus somewhat narrowly swollen; posterolateral
slopes to the deflected cardinal extremities short and steep.

Brachial interior with moderately elevated notothyrial platform, septumlike

368 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

cardinal process; low median ridge extending to the middle, and short, stout,
flaring brachiophores.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EIOIGE Pe cy de eee eens 8.7 8.6 11.0 9.5 5.0
Paratype (116032c).. 10.5 10.1 12.8 10.9 4.6

Types.—Holotype: 1169324; figured paratypes: 110054, 116932b; unfigured
paratype: 116932c.

Horizon and locality—Bromide formation (Mountain Lake member—bed 8)
in Oklahoma: From a cut on Oklahoma Highway 18, center NW} sec. 11, T.
1 S., R. 3 E., 1.8 miles south of Sulphur; Spring Creek, N4 sec. 17, T. 2 S.,
R. 1 W.; Murray County.

Discussion—This species is characterized by its subcarinate pedicle valve and
the fairly deep and narrow sulcus on the brachial valve. It differs from G. costel-
lata of higher Bromide beds in somewhat smaller size, less robust form, narrower
profiles, and somewhat more delicate ornamentation. It is a much larger and
more elongate shell than G. uncinata from the lower Bromide (Mountain Lake
member ).

GLYPTORTHIS EQUICONVEXA Cooper, new species
Plate 47, D, figures 18-30; plate 108, C, figures 15-18

Shell fairly large for the genus, subquadrate in outline but with the width
slightly greater than the length; valves of nearly equal depth; anterior com-
missure broadly uniplicate ; hinge narrower than the width at the middle; sides
nearly straight; anterolateral extremities narrowly rounded; anterior margin
gently rounded to somewhat truncated. Surface costellate ; costellae unequal in
size, appearing in 4 generations; about 5 costellae in 5 mm. at the front margin;
imbrications fairly closely crowded.

Pedicle valve fairly strongly and evenly convex in lateral profile with the
greatest convexity at about the middle; anterior profile swollen in the median
region and with gently dipping lateral slopes. Beak incurved ; umbo swollen and
with steep umbonal slopes; sulcus originating about 4 mm. anterior to the beak,
deepening and widening anteriorly but never attaining great depth; width of
sulcus about one-third shell width. Flanks bounding sulcus gently swollen; pos-
terolateral slopes short, moderately steep. Interarea moderately long, almost
orthocline, gently curved; beak incurved; delthyrium narrow.

Brachial valve unevenly convex in lateral profile with the umbonal region
strongly curved but the remainder of the valve gently convex; anterior profile
swollen and fairly evenly convex; umbo strongly curved and swollen; umbo
sulcate, sulcus narrow, short, becoming obsolete about 6 mm. anterior to the
beak; fold low, indistinctly defined from about 6 mm. anterior to the beak to
the front margin; flanks bounding fold inflated; umbonal slopes to the small de-
pressed posterolateral areas short and steep. Beak strongly incurved; interarea
short and curved.

PART? T CHAZYAN AND RELATED BRACHIOPODS—COOPER 369

Pedicle interior with short, receding dental plates ; deep delthyrial cavity with
well-impressed muscle area somewhat elevated at its anterior end; vascula media
slightly divergent, short ; reniform ovarian markings moderately impressed.

Brachial interior with deep notothyrial chamber, strongly elevated notothyrial
platform ; thin cardinal process and stout divergent brachiophores. Median ridge
low, extending to the middle.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FLOLOLY pe: GrNe suceve: es « 14.6 127, 17.3 16.0 10.3
Paratype (116934a). 14.3 14.1 16.9 ? 15.2 11.0

Types.—Holotype: 116934b; figured paratypes: 116934a,c, 116933a,b; un-
figured paratype: 116934d.

Horizon and locality—Shippensburg formation (Pinesburg member-Echino-
sphaerites zone) in Maryland: In a cut on U. S. Highway 40, just west of
Conococheague Creek at Wilson, 7 miles west of Hagerstown, Williamsport
(15’) Quadrangle.

Botetourt formation in Virginia: On the south side of the road 0.2 mile east
of Strasburg, Strasburg (15’) Quadrangle.

Discussion.—This species is characterized by the obese valves and their nearly
equal depth. The species is somewhat suggestive of large individuals of G. wir-
ginica, but that is a wider form having a sulcate pedicle valve and a low fold on
the brachial valve. Glyptorthis equiconvexa has a subquadrate outline and thus
is quite unlike G. subcircularis which has strongly convex valves and a robust
form.

GLYPTORTHIS GLYPTA Cooper, new species
Plate 48, B, figures 7-11; plate 108, A, figures 1-5

Shell small for the genus, wider than long, with the hinge equal to, or slightly
less than the greatest shell width, or forming the widest part. Cardinal extremi-
ties varying from slightly acute to slightly obtuse. Lateral margins slightly con-
vex; anterior margin broadly rounded. Anterior commissure slightly sulcate.
Surface costate, costae narrowly rounded, interspaces broad; costae numbering
about 15, some costae fasciculate in front by intercalation of a generation on one
or each side of the primary costa. Lamellae distant on body of shell, crowded
anteriorly in old specimens.

Pedicle valve moderately convex in lateral profile; broadly convex in anterior
profile. Fold generally low, not clearly perceptible in the young, most clearly
defined by the strong elevation of the median costa in the posterior half; flanks
descending gently to the lateral margins. Beak extending slightly posterior to
the posterior margin. Interarea long, strongly apsacline. Interior with elongate,
narrow diductor impressions and strongly elevated adductor track. Pallial
sinuses not well defined.

Brachial valve moderately convex in lateral profile with the most strongly
arched part in the posterior third; anterior profile very broadly and gently con-

370 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

vex. Posterior third somewhat swollen; sulcus originating almost at the pos-
terior margin defined chiefly by the median depression corresponding to the
median costa of the pedicle valve, extending to the anterior margin. Flanks mod-
erately convex with gentle slopes to the posterolateral areas. Interarea anacline,
fairly long. Median ridge extending slightly anterior to the middle; brachio-
phores short, cardinal process moderately stout.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PAQIOEV PE) ag has beee ceems ? 6.8 8.6 7.5 2.5
Paratype (110067f) ..... 5.8 ? 7.8 5.9 2.6

Types.—Holotype: 110067c; figured paratypes: 110067d-f, 116935a-c; un-
figured paratypes: 110067a,b, 116935d-f.

Horizon and locality.—Effna formation, Effna-Rich Valley formations in Vir-
ginia: At Porterfield Quarry, 5 miles east of Saltville, Maccrady (T.V.A.
218-NW) Quadrangle; opposite junction of highway with Hays Creek, 2 miles
northwest of Brownsburg, Lexington (15’) Quadrangle; McNutt Quarry, 12
miles southwest of Bland, Burkes Garden (15’) Quadrangle.

Pratt Ferry formation in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton
(15’) Quadrangle.

Discussion.—This species can be recognized by its small size and the distant
broad costae on the exterior. It differs from all other species herein described
in the character of its ornamentation.

GLYPTORTHIS IRREGULARIS Cooper, new species
Plate 45, A, figures 1-6

Shell of about medium size for the genus, wider than long; unequally bicon-
vex, the pedicle valve having the greater convexity; hinge narrower than the
greatest shell width which is at the middle; anterior commissure rectimarginate ;
side gently rounded, anterior margin broadly rounded; surface multicostellate,
costellae about 32 in number, crossed by strong imbricating lamellae about 2 to
the millimeter.

Pedicle valve unevenly convex in lateral profile with the most convex part at
the umbo; anterior profile fairly strongly convex, the convexity greatest in the
median region with the sides sloping steeply to the margins. Umbo somewhat
narrowly swollen; anterior portion somewhat flattened; lateral slopes to the
cardinal extremities steep. Interarea slightly curved, strongly apsacline. Teeth
small, delthyrial cavity deep ; muscle field long, extending to the middle ; anterior
ends of diductor scars extended anterior to adductor track.

Brachial valve gently convex in lateral profile, broadly and gently convex in
anterior profile, umbo sulcate ; sulcus broad and shallow, scarcely defined at the
anterior margin ; flanks bounding sulcus gently swollen and with gentle slopes to
the posterolateral areas. Brachiophores widely divergent, stout ; notothyrial plat-
form somewhat thickened; cardinal process a thin ridge.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 372

Measurements in mm.— Hinve
Length Width width Thickness

Holotype (pedicle valve) ............. 10.0 12.5+ 12.0 4.0
Paratype ( “ i, PIRLOOSOR) we ass 3 10.3 12.1 ? ?
- (brachial valve 116036e)..... 10.2 13.8 12.4 3.0
i Cer ona NPVEGSOU 2. > « 8.4 12.3 11.9 1.6

Types.—Holotype ; 116936a; figured paratypes: 116936d,e; unfigured para-
types: 116936b,c,f.

Horizon and locality Wardell formation in Tennessee: In Raccoon Valley,
$ mile northeast of Fleanor Mill, Powell Station (T.V.A. 137-SE) Quadrangle.

Pierce formation in the Central Basin of Tennessee: At Pierce Mill, 74 miles
north of Murfreesboro, Rutherford County.

? Lebanon formation in the Central Basin of Tennessee: On Tennessee High-
way 16, 5.1 miles north-northwest of Shelbyville, Bedford County.

Discussion.—This is a somewhat variable species characterized by a fairly deep
pedicle valve but a very shallow brachial valve. It is suggestive of G. assimilis,
but that is a more robust form having more nearly equally deep valves.
Glyptorthis virginica is similar but differs in more robust form, a more promi-
nent brachial sulcus, and deeper brachial valve.

GLYPTORTHIS MULTICOSTELLATA Cooper, new species
Plate 46, F, figures 35-40

Shell large for the genus, wider than long; valves subequally convex; hinge
narrower than the greatest shell width at the middle; sides gently rounded;
anterior margin broadly rounded; anterior commissure rectimarginate ; surface
multicostellate ; costellae uneven in size, the primary ones the larger and sur-
rounded by finer costellae of several generations ; about 10 costellae in 1 mm. at
the front margin. Imbrications about 3 to the millimeter.

Pedicle valve gently convex in lateral profile with the maximum convexity in
the median half; anterior profile broadly convex ; umbonal region slightly swollen ;
median region gently convex; lateral and posterolateral slopes gentle. Interarea
flat, almost catacline ; delthyrial cavity wide and deep; anterior ends of diductor
scars extended anterior to delthyrial cavity ; dental plates well developed ; adduc-
tor track short, somewhat elevated.

Brachial valve moderately convex in lateral profile with the greatest convexity
in the median region; anterior profile broadly but moderately convex ; umbonal
and median regions swollen; umbo sulcate; sulcus narrow and moderately deep
but shallowing and disappearing near the front margin; flanks bounding sulcus
moderately swollen; posterolateral areas somewhat flattened; posterolateral
slopes moderately steep, short. Notothyrial platform thickened ; brachiophores
stout and short; cardinal process prominent, stout.

Measurements in mm.—

Hinge
Length Width width Thickness
Holotype (pedicle valve).............. 11.9 16.9 14.5 3.9
Paratype (brachial valve 116938c)...... 127 16.4 14.1 3.0

372 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 116938b; figured paratypes: 116938a,c,e; unfigured para-
type: 116938d.

Horizon and locality —Ridley formation in Georgia: On U. S. Highway 27
just north of Chickamauga Creek, Kensington (T.V.A. 106-SE) Quadrangle.

Discussion—This species is characterized by its rectangular outline and fairly
strongly convex brachial valve. It is very suggestive of G. virginica but differs
in having finer ornamentation, a pedicle valve not flattened in the anteromedian
portion, a more convex brachial valve, and a less pronounced brachial sulcus.

GLYPTORTHIS OBESA Cooper, new species
Plate 47, B, figures 9-12

Shell of medium size for the genus, strongly biconvex with the length and
width subequal. Lateral margins gently rounded to nearly straight ; anterior mar-
gin strongly rounded. Anterior commissure rectimarginate. Surface multicostel-
late, about 7 costellae occupying the space of 5 mm. at the front margin.

Pedicle valve subhemipyramidal in outline; lateral profile moderately convex
with the greatest convexity located in the posterior half. Anterior profile strongly
convex. Valve strongly swollen in the midregion, with steep lateral slopes.
Slopes to cardinal extremities gently convex. Interarea long, strongly apsacline.

Brachial valve wider than long, strongly convex in both profiles and with the
greatest convexity located at the middle. Midregion swollen. Anterior and
lateral slopes steep. Slopes to cardinal extremities gently concave. Median sulcus
defined at the posterior only, obsolete at the front margin of an adult. Interarea
long, orthocline.

Interior with heavy and swollen structures. Pedicle muscle field narrow,
thickened at the front and with an elevated adductor track. Ovarian fields large
and occupying most of the lateral areas of the interior. Cardinalia of the brachial
valve ponderous.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve) ........ 14.6 ? 14.2 12.3 5.3
Paratype (brachial valve 110068c). 11.7 15.2 ? ? ?

Types.—Holotype: 110068d; figured paratypes: 110068a,c; unfigured para-
types: 110068b,e-g.

Horizon and locality.—Bromide formation (Mountain Lake member) in Okla-
homa: A little north of the middle of sec. 32, T. 2 S., R. 2 E., 2 to 3 miles
northeast of Springer, Carter County.

Discussion.—This species is closest to Glyptorthis bellarugosa of any described
in this paper. It differs, however, in the possession of a finer sculpture and more
convex valves.

GLYPTORTHIS RARA Cooper, new species
Plate 44, B, figures 6-10
Small, characterized by its great width and few strong imbrications. Orna-

mentation consisting of 20 costae interrupted by 8 strong imbrications. Second-
ary costae intercalated at about the middle. —

PART, tT CHAZYAN AND RELATED BRACHIOPODS—COOPER 373

Pedicle valve much deeper than the brachial valve and having a fairly long,
nearly procline interarea. Most convex at the umbo with long, gently concave
umbonal slopes.

Brachial valve very gently convex in both profiles and marked medially by a
shallow, narrow sulcus which originates at the umbo and extends to the front
margin. Sulcus occupied by a single costa.

Measurements in mm.—Holotype, length 5.4, brachial length 5.1, midwidth
8.4, hinge width 8.2, thickness 3.6.

Types.—Holotype: 110069a ; unfigured paratype: 110069b.

Horizon and locality.— Benbolt formation in Virginia: 1 mile west of Rye
Cove, Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion—The strong costae, few imbrications, and great width of this
little species distinguish it from G. glypta and G. concinnula which are both of
small size.

GLYPTORTHIS SENECTA Cooper, new species
Plate 45, B, figures 7-14

Small for the genus, strongly biconvex, slightly wider than long; cardinal ex-
tremities nearly a right angle or slightly obtuse ; hinge slightly narrower than, or
nearly equal to, the width of the valves at the middle where the maximum width
is located. Lateral margins nearly straight; anterior margin broadly rounded ;
anterior commissure uniplicate. Surface finely costellate, 4 to 7 costellae occupy-
ing a space of 2 mm. at the anterior margin. Concentric lamellae fairly closely
crowded but variable.

Pedicle valve moderately convex in lateral profile, but strongly convex in an-
terior profile. Beak prominent ; umbonal region convex ; median region nearly to
front fairly strongly swollen and with steep sides descending to the front and lat-
eral margins. Interarea long, apsacline. Muscle field with elongate and narrow
diductor scars; adjustor impressions small, located at base of dental plates, not
distinct. Adductor track wide, often strongly elevated. Dental plates receding.

Brachial valve slightly less convex in lateral profile than the pedicle valve;
broadly convex in anterior profile. Umbonal region convex, sulcus originating on
umbo, shallow, widening to about the middle where it is lost in the anterior third.
Flanks convex with moderately steep slopes. Inside the dorsal valve the median
ridge extends to a point slightly anterior to the middle. Cardinalia strong and
typical for the genus.

Measurements in mm.—

Hinge
Length Width width Depth
Holotype (pedicle valve)........... 9.2 10.1 9.4 4.6
Paratype ( “ “ yroozary 2° o7 10.1 8.8 3.6
ss (brachial valve 110070g).. 7.5 9.5 9.4 2.8
‘ eS * UTLOOZOe))..., 7.0 8.5 8.0 2.4

Types——Holotype: 110070h; figured paratypes: 110070c,d,f,g,1; unfigured
paratypes : 110070a,b,e.
Horizon and locality—Poteet formation (Yellow Branch member=9-foot

374 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

marble) in Virginia: On the road beside Yellow Branch, 5 miles southeast of
Rose Hill, Rose Hill (T.V.A. 161-NW) Quadrangle.

Discussion.—This species is characterized by its rectangular form, the an-
teriorly nearly obsolete brachial sulcus, and the fine costellae. Some pedicle valves
show the development of a distinct sulcus at the front margin, and the cor-
responding part of the brachial valve is so swollen that the sulcus is obliterated.
This species is quite unlike any of those described herein. It differs from G. con-
cinnula by its anteriorly obsolete brachial sulcus and much more subdued cos-
tellae. It is a much smaller shell than G. assimilis with finer costellae and less
pronounced sulcus.

GLYPTORTHIS SUBCARINATA Cooper, new species
Piate 46, D, figures 18-23

Shell small, wider than long with the hinge about equal to or slightly less than
the width at the middle. Sides rounded; anterior margin truncated. Anterior
commissure sulcate. Surface multicostellate, costellae numbering about 30, sepa-
rated by striae about equal to the costellae in width.

Pedicle valve moderately convex in lateral profile with the deepest part near
the middle; anterior profile narrowly convex with moderately steep lateral
slopes; umbo narrowly convex, the convexity and a strong median costella ex-
tending to the front margin as a subcarinate fold; median and anteromedian
region somewhat swollen with long, fairly steep lateral and posterolateral slopes.
Interarea nearly catacline.

Brachial valve fairly evenly and gently convex in lateral profile; moderately
convex and medianly deeply sulcate in anterior profile; umbo somewhat swollen,
deeply sulcate; sulcus deepening and widening anteriorly to the front margin.
Flanks bounding sulcus swollen; lateral and posterolateral slopes short and
gentle.

Measurements in mm.—Holotype, length 6.6, brachial length 6.3, width 9.1,
hinge width 8.2, thickness 3.7.

Type.—Holotype: 117987.

Horizon and locality—Lower Sevier formation in Tennessee: 4+ mile north-
east of Miser, Louisville (T.V.A. 138-SE) Quadrangle.

Discussion.—This is a small species having the appearance of G. uncinata but
not so deeply sulcate nor so strongly costellate. It is much more strongly sul-
cate than G. uniformis and is also, at least as now understood, a somewhat
smaller shell.

GLYPTORTHIS SUBCIRCULARIS Cooper, new species
Plate 49, G, figures 33-40

Shell large for the genus, slightly wider than long and with the hinge con-
siderably narrower than the greatest width which is at the middle, sides rounded,
anterior margin gently rounded to truncated. Anterior commissure gently
uniplicate ; valves subequally convex; surface multicostellate, costellae broadly
angular, 5 in 5 mm. at the front margin.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 375

Pedicle valve moderately strongly convex in lateral profile with the greatest
convexity in the posterior half; lateral profile strongly and broadly convex;
umbonal and lateral regions swollen; sulcus originating about 12 mm. anterior to
the beak, narrow and shallow and forming a short tongue; slopes to cardinal
extremities very steep. Median costella extending for 3 mm. anterior to the
beak where it trifurcates, the resulting 3 costellae extending to the anterior mar-
gin. Interarea curved, gently apsacline.

Brachial valve strongly convex in lateral profile with the greatest convexity
at about the middle; anterior profile strongly arched and swollen; median re-
gion strongly swollen with steep slopes to all margins ; umbo sulcate, sulcus nar-
row and deep, extending to about the middle where its surface is elevated into
a low fold; sulcus occupied by 2 costellae at posterior; 2 costellae intercalated
inside the posterior 2 at 3 mm.; 2 additional costellae intercalated at about 6
mm, to form a median fascicle of 6 costellae which form the fold. Interarea long
and strong, curved to overhang the delthyrium.

Pedicle interior characterized by a deep and broad delthyrial cavity; muscle
field wide with diductor ends extended anterior to the delthyrial cavity ; adductor
track short, elevated; median ridge thick. Teeth stout, fossettes deep. Dental
plates long and thick, umbonal cavities nearly filled.

Brachial valve with short, stout brachiophores supported by thick swelling of
the notothyrial platform ; cardinal process bulbous in the adult.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
HAGIOEY PE) inact ieisicise eps s saclay eis sieges 17.9 16.7 20.4 12.2 II.9
Paratype (pedicle valve 116940b).. 16.2 ? 17.6 12.6 5.5
" (brachial valve 116940a). ? 17.9 20.0 13.2 7.0

Types.—Holotype: 84015; figured paratypes: 116940a,b.

Horizon and locality—Decorah formation (Ion member) in Iowa: At
Decorah.

Same horizon in Minnesota: In a road cut 1.1 miles east of U. S. Highway
52, on the south edge of Cannon Falls; and at Kenyon, Goodhue County.

Discussion.—The rounded outlines and strongly convex valves set this species
apart from any of the Appalachian species except G. equiconvexa. The latter is
very easily separated from G. subcircularis by its subquadrate form and heavy
shells. Glyptorthis subcircularis is similar to G. bellarugosa and is probably re-
lated to it. The stronger costellae, the subcircular form, the outline, and strong
convexity serve to distinguish the two species.

GLYPTORTHIS SULCATA Cooper, new species
Plate 46, E, figures 24-34
Hebertella bellarugosa RAyMonD, Ann. Carnegie Mus., vol. 7, No. 2, p. 245, pl. 36, figs. 8, 9,
IQII.

Shell small for the genus, with the length and width about equal. Hinge equal
in width to the width of the shell or a little less than the greatest width. Cardi-
nal extremities slightly obtuse. Lateral margins straight to well rounded ; front

376 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

margin broadly rounded. Anterior commissure gently sulcate. Surface multi-
costellate ; costellae subangular and appearing in 3 generations by implantation.
A specimen about 12 mm. in length has about 40 costellae which are crossed by
closely spaced imbricated lamellae.

Pedicle valve strongly convex in lateral profile with the greatest convexity be-
tween the umbo and the middle of the valve. Anterior profile strongly convex.
All slopes from swollen preumbonal region steep. Interarea curved, elongate,
apsacline. Beak pointed forming an angle of 110°. Delthyrium narrow.

Brachial valve unequally convex in lateral profile, the umbonal region having
the greater convexity. Moderately convex anterior to the umbonal region. An-
terior profile less convex than that of the pedicle valve and medially sulcate.
Sulcus deep at the umbo, widening anteriorly and in old shells becoming much
shallower and nearly obsolete at the front margin. Sulcus occupying 5 mm. of
the front margin of a specimen 12.5 mm. wide. Two costellae occupying the
sulcus at the beak, increasing to 8 at the front margin of an adult. Flanks bound-
ing sulcus moderately convex; slopes to the cardinal extremities steep and con-
cave. Beak much incurved; interarea short.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype. 33.2% chai 10.5 9.0 10.8 9.3 6.8
Paratype (110076a).. 12.2 10.8 12.7 9.5 9.0
ss (110076b).. 12.0 10.6 12.8 10.0 7.0

Types.—Holotype: 110075a; figured paratypes: 110074, 110075b; unfigured
paratypes: I10075c; 110076a-e.

Horizon and locality.—Crown Point formation (bed B, division 3 of Brainerd
and Seely) in New York: At Chazy and vicinity, Rouses Point (15’) Quad-
rangle; Valcour Island and quarry 4 mile north of the Normal School, Platts-
burg, Plattsburg (15’) Quadrangle.

Discussion.—This species is characterized by its strongly convex valves, swol-
len umbonal regions and prominent sulcus on the brachial valve. The species has
some features that remind one strongly of G. concinnula but has a much larger
shell and much more convex valves. Resemblance to G. bellarugosa, with which
it has long been confused, is remote. Although the size of G. sulcata and of the
type specimens of G. bellarugosa are about the same, the Chazyan shell is more
convex in both valves and has deeper sulcus on the brachial valve and a more
incurved beak on the pedicle valve.

GLYPTORTHIS TRANSVERSA Cooper, new species
Plate 50, F, figures 24-28

Shell small for the genus, width about 14 times the length; outline subellipti-
cal; hinge narrower than the width at the middle; sides somewhat narrowly
rounded; anterior margin gently rounded; valve subequally convex; anterior
commissure rectimarginate. Surface marked by about 26 narrowly rounded

PART, 1 CHAZYAN AND RELATED BRACHIOPODS—-COOPER 377

costellae with interspaces about equal to the width of the costellae ; imbrications
3 or 4 to the millimeter.

Pedicle valve with lateral profile gently convex; anterior profile very broadly
and moderately convex ; umbonal and median regions moderately convex; pos-
terolateral slopes moderately steep; interarea curved, strongly apsacline.

Brachial valve moderately convex in lateral profile and very broadly convex
in anterior profile; umbo sulcate, sulcus shallow; scarcely attaining the anterior
margin; flanks bounding sulcus moderately swollen, the swelling extending to
the posterolateral areas which are not depressed.

Measurements in mm.—Holotype, length 5.8, brachial length 5.2, width 7.8,
hinge width 6.6, thickness 3.3.

Type—Holotype: 116939.

Horizon and locality.—St. Martin formation in Quebec, Canada: At Belanger,
2 miles south of Cap St. Martin.

Discussion.—This little species is not like any of the other Chazy species of
Glyptorthis, most of which have the unequal costellae, subquadrate outline, and
wide sulcus of G. concinnula and G. sulcata. Its transverse form and subequal
costellae suggest some of the stratigraphically higher species, but it is not sub-
carinate like the small Benbolt or Hogskin forms.

GLYPTORTHIS UNCINATA Cooper, new species
Plate 43, B, figures 4-7; plate 46, B, figures 5-10; plate 50, E, figures 19-23

Shell small for the genus, wider than long with the length about two-thirds the
width; hinge forming the widest part or narrower than the width at the middle
in adults ; sides nearly straight, slightly oblique or gently rounded ; anterior mar-
gin gently rounded; anterior commissure gently and broadly sulcate; surface
ornamented by 22 to 24 subangular costae crossed by strong imbrications about
2 to the millimeter ; imbrications often produced over the costella into a hollow
spine.

Pedicle valve gently convex in lateral profile; somewhat broadly convex in
anterior profile with the median region narrowly rounded and the sides slop-
ing steeply; median region narrowly swollen from umbo to anterior margin to
produce a poorly defined fold. Interarea long; nearly catacline.

Brachial valve very gently convex in lateral and anterior profiles; umbo sul-
cate ; sulcus deepening and widening anteriorly to occupy about half the width
at the front margin; sulcus occupied by 4 to 6 costellae.

Pedicle interior with small teeth ; poorly developed lateral plates ; short, widely
divergent, receding dental plates; deep delthyrial cavity but lightly impressed
short muscle field. Brachial interior with thickened cardinal process, short
brachiophores, low median ridge, and not greatly thickened notothyrial platform.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hicidtype™ ety. cc eee es 6.1 6.0 8.7 8.6 3.9

Paratype (116942) .... 5.5 5.0 7.5 7.8 312

378 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 116943a ; figured paratypes: 116941a,b, 116942 ; unfigured
paratypes: 116943b,c.

Horizon and locality—Bromide formation (Mountain Lake member—middle
of bed 6) in Oklahoma: At Rock Crossing of Hickory Creek, center sec. 35,
T.5 S., R. 1 E., Carter County ; McLish Ranch, sec. 24, T. 1 S., R. 7 E., Johns-
ton County; Nebo, Murray County.

Discussion.—This is a small, somewhat transverse form with fairly strong
costellae. It is not to be confused with either of the other two Oklahoma species
which are much larger and squarer forms. The small Benbolt and Hogskin
species are more finely costellate than G. uncinata.

GLYPTORTHIS UNIFORMIS Cooper, new species
Plate 43, E, figures 18-21; plate 46, C, figures 11-17; plate 40, I, figures 45-51

Shell of about medium size for the genus, wider than long; hinge narrower
than the shell width at the middle; sides and anterior margin gently rounded;
anterior commissure rectimarginate ; surface multicostellate, costellae numbering
42 to 44; imbrications 3 to the millimeter.

Pedicle valve unevenly convex in lateral profile with the maximum convexity
in the posterior half; anterior half somewhat flattened; anterior profile nar-
rowly rounded in the median part with flat and steep slopes to the margins;
umbonal region gently swollen ; median and anterior regions somewhat flattened ;
posterolateral slopes fairly long and gentle. Interarea short, nearly catacline.

Brachial valve moderately convex in lateral profile with the most convexity
in umbonal region; anterior profile broadly convex but with a median depres-
sion ; umbonal region somewhat swollen ; sulcus originating at the umbo, expand-
ing anteriorly where it occupies somewhat less than half the width; sulcus de-
fined by marginal costellae larger than the surrounding ones; sulcus occupied by
8 costellae, 2 secondary, 4 tertiary, the remainder implanted on the margin,
flanks bounding sulcus gently swollen.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype aeridsntnee 10.6 10.5 13.0 12.2 6.1
Paratype (116944a).. 9.9 9.6 12.0+- 11.4 5.5

Types—Holotype: 116945a; figured paratypes: 116944a, 116945b, 116946a,b;
unfigured paratypes: 116944b,c.

Horizon and locality.—Benbolt formation in Virginia: West slope of hill 4
mile east of Cedar Point School, Hilton (T.V.A. 197-NW) Quadrangle; Rye
Cove, Clinchport (T.V.A. 188-NW) Quadrangle; north side of U. S. Highway
19, 12 miles southeast of Hansonville Post Office, Brumley (T.V.A. 205-SE)
Quadrangle.

Benbolt formation in Tennessee: At the road corner southwest of Fleanor
Mill ; roadside 1.6 miles northeast of Heiskell, Powell Station (T.V.A. 137-SE)
Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 379

Sevier formation in Tennessee: + mile northwest of Miser, Louisville (T.V.A.
138-SE) Quadrangle.

Discussion.—Of described species this one is most suggestive of G. multi-
costellata, but it differs in having a less convex brachial valve and a more promi-
nent sulcus on the brachial valve. It is also reminiscent of G. virginica, but that
species is more coarsely costellated.

GLYPTORTHIS UNIPLICATA Cooper, new species
Plate 47, C, figures 13-17

Shell of about medium size for the genus, slightly wider than long; hinge nar-
rower than width at middle; sides nearly straight or gently rounded; anterior
margin gently rounded; anterior commissure gently uniplicate; surface finely
multicostellate ; costellae numbering about 55, subangular.

Pedicle valve unevenly convex in lateral profile with the posterior third con-
vex and the anterior two-thirds somewhat flattened; anterior profile broadly
and gently convex ; umbonal and median regions swollen; anterior half occupied
by a moderately deep and narrow sulcus that forms a short tongue; areas flank-
ing sulcus gently swollen; lateral slopes short and moderately steep. Interarea
gently curved, gently apsacline.

Brachial valve gently convex in lateral profile but with the umbo fairly strongly
curved ; anterior profile broadly and gently convex; umbonal and median region
swollen; umbo sulcate, sulcus narrow and shallow, extending to a point slightly
anterior to the middle where it merges in the general valve convexity to form
an indistinct fold; sulcus occupied by about 8 costellae. Flanks bounding sulcus
slightly swollen; posterolateral slopes gentle.

Measurements in mm.—

Hinge
Length Width width Thickness
Holotype (pedicle valve) ............. 13.4 14.3 12.3 5.4
Paratype ( “ Piiib RAE GOA VA) at ex ose 10.9 12.8 11.6 3.8

Types.—Holotype: 116947b; figured paratypes: 116947a,c; unfigured para-
types : 116947¢,e.

Horizon and locality.—Benholt formation (basal part of Echinosphaerites bed
directly overlying the marble) in Virginia: 4 mile northeast of Speers Ferry,
Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—This species is characterized by its rounded outlines and fine
costellae. It is suggestive of G. bellarugosa but differs from that species in hav-
ing a fairly prominent pedicle sulcus which is an unusual feature in this genus.
The only other species with a marked pedicle sulcus is G. equiconvexa, but that
is a thick-shelled and robust form having a subquadrate outline.

GLYPTORTHIS VIRGINICA Cooper, new species
Plate 48, D, figures 19-33

Glyptorthis bellarugosa Wittarp (not Conrad), Bull. Mus. Comp. Zool., Harvard Coll.,
vol. 68, No. 6, p. 264, 1928.

380 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

G. aff. G. bellarugosa Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 93, pl. 90, figs. 25-32,
1942.

Shells of medium to large size for the genus, rectangular in outline; slightly
wider than long. Hinge narrower than the width at the middle. Cardinal ex-
tremities obtuse or forming a right angle. Lateral margins straight or sloping
outward to about the middle. Anterolateral extremities narrowly rounded ; front
margin straight or slightly emarginate. Greatest width slightly anterior to mid-
dle. Anterior commissure rectimarginate to slightly sulcate. Valves subequal
in depth; strongly convex. Surface multicostellate, costellae added by implanta-
tion and bifurcation in 3 generations. Seven costellae occupy the space of 5 mm.
at the front of a valve 17 mm. in length, and §8 costellae were counted on the
same valve. Costellae crossed by imbrications swollen into blunt spines. Imbri-
cations marked by fine, concentric, elevated threads.

Pedicle valve unequally convex in lateral view with the greatest convexity lo-
cated just posterior to the middle. Anterior profile broadly arched. Umbo flat-
tened ; slopes to the posterolateral margins moderately steep and slightly concave.
Median region swollen; anterior and anterolateral slopes convex, not very steep.
Beak only slightly elevated above the posterior margin. Palintrope strongly
apsacline to procline; interarea slightly curved.

Brachial valve unequally convex in lateral profile; greatest convexity located
slightly anterior to the umbo, anterior two-thirds flattened. Anterior profile
moderately convex, broadly indented medially. Sulcus deepest and narrowest at
the umbo, widening anteriorly to occupy about one-third the width at the an-
terior margin. Two primary costellae occupying the sulcus at the umbo, increas-
ing to 7 or 8 costellae at the front margin. Costellae bounding sulcus often
stronger and more prominent than the rest. Flanks bounding sulcus moderately
swollen; slopes to the lateral and posterolateral margins steep, concave. Beak
strongly incurved, often overhanging pedicle interarea; umbo swollen; umbonal
region forming deepest part of valve.

Pedicle interior with elongate diductor impressions extending a short distance
anterior to the adductor track to the posterior one-third to one-half of the valve.
Adductor track wide ; adjustor scars small. Median ridge of brachial valve mod-
erately elevated; brachiophores and cardinal process small.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
UIE C IG. oo wins ob ne dies a e haae's 15.5 15.3 18.7 17.0 10.8
Paratype (110082c)........ 11.3 11.3 14.3 12.8 6.5
“s (98200b) ) 20 Fi 13.2 12.6 16.4 14.3 7.5
fs (110082e)........ 10.3 10.1 13.4 11.3 5.3
s (110086a)........ 7.8 7.6 9.8 8.8 4.8
: (GGIOOSG6D)) ce 1c. 5.4 5.6 7.6 7.0 3.3
4 (EYOOSGE)) 5 oss s,s 3.6 3.5 5.1 4.4 2.0
a (UIOOSGE ioe cise one 17 1.9 2.4 2.1 1.0

Types.—Holotype: 98209a ; figured paratypes: 98209d, 110082a-e; unfigured
paratypes: 98209b,c,e, 110082f-h, 110086a-d.

PART IT CHAZYAN AND RELATED BRACHIOPODS—-COOPER 381

Growth.—A series of 25 specimens ranging in size from 1.75 mm. in length
by 2.5 mm. in width to 15 mm. long by 19 mm. wide shows a progressive length-
ening of the shell. The largest specimen in the collection shows that this length-
ening has been carried so far that old adults have the length and width almost
equal. The youngest specimen shows 12 primary costellae and the intercalation
of the second generation.

Horizon and locality—Wardell formation in Virginia: At Rye Cove and its
immediate vicinity, Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—Except for G. assimuilis this species attains the largest size of any
Glyptorthis encountered in the rocks studied. G. virginica can be recognized
by the fact that the pedicle and brachial beaks have about the same distance from
the margins which gives the valves approximately the same length/width ratio.
In some specimens the brachial length actually exceeds that of the pedicle valve,
but usually the pedicle valve is slightly longer than the other. Features that will
help in recognition of G. virginica are the rectangular form, the convex umbonal
regions, and the broad, shallow sulcus. G. virginica is very close to G. assimilis
but differs in having a more transverse outline and more subdued ornamenta-
tion. Only in extreme cases do the proportions of G. virginica approach those
of G. assimilis.

GLYPTORTHIS sp. 1
Plate 46, A, figures 1-4

This is probably a new species represented by a fine pedicle valve and a crushed,
immature complete specimen. Pedicle valve somewhat rectangular in outline;
cardinal extremities forming a right angle; sides nearly straight and perpendicu-
lar to the hinge; posterolateral extremities narrowly rounded; anterior margin
gently rounded ; interarea nearly catacline, not curved ; teeth small; lateral plates
well developed; dental plates short and receding; muscle area with prominent
wide diductor scar and a narrow, linear adductor track elevated anteriorly and
with a short median ridge anterior to it. Lateral and anterior profiles gently
convex.

Surface marked by about 37 narrowly rounded to subangular costellae sepa-
rated by striae equal to or slightly less than the width of adjacent costellae ; im-
brications broad, about 3 to the millimeter.

Measurements in mm.—116948, length 9.2, width 10.8, hinge width 9.8, thick-
ness 3.6.

Figured specimen.—1 16948.

Horizon and locality—Dark shale just below Eureka quartzite in Nevada:
North-facing nose of hill 8167, Martins Ridge, Monitor Range, Roberts Moun-
tains (1°) Quadrangle.

Discussion.—The subquadrate outline and inflated pedicle valve are not like
any other described in this report. In absence of the brachial valve it is inadvisa-
ble to use a new specific name.

382 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

GLYPTORTHIS sp. 2
Plate 49, E, figures 22-26

Shell small for the genus, wider than long ; unequally biconvex ; hinge slightly
narrower than the width at the middle; sides gently rounded; anterior commis-
sure rectimarginate; anterolateral extremities narrowly rounded; front margin
very gently curved; surface multicostellate ; costellae numbering about 27, and
intercalated in 3 generations after the primaries.

Pedicle valve unevenly convex in lateral profile, the posterior half gently con-
vex, the front half somewhat flattened ; anterior profile somewhat narrowly con-
vex in the median region but with steep lateral slopes; umbo and posterior half
swollen, the slopes in all directions steep to the margins. Median half flattened.
Interarea long, strongly apsacline.

Brachial valve gently convex in lateral profile; anterior profile broadly con-
vex and with median region sulcate; umbo sulcate; sulcus forming a triangular
depressed area; sulcus occupying about half the width at the anterior margin;
sulcus bounded by 2 strong costellae on each side and occupied by 6 costellae, 2
secondary, 2 tertiary and 2 quaternary in appearance.

Measurements in mm.—1169492, length 4.9, brachial length 4.6, width 6.4,
hinge width 5.6, thickness 2.6.

Figured specimen.—116949a.

Horizon and locality—Hogskin member of the Lincolnshire formation in
Tennessee: On Maynardville Pike, 1.7 miles north-northeast of Hall Crossroad,
Fountain City (T.V.A. 146-SW) Quadrangle; 3 mile east-northeast of Red Hill,
4 miles west-southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle ;
I mile southwest of Washburn, Dutch Valley (T.V.A. 154-SE) Quadrangle.

Discussion.—This little species is characterized by a subcarinate pedicle valve
and a fairly strongly sulcate brachial valve. It has some resemblance to G. uni-
formis but is smaller and more sulcate. It resembles G. subcarinata in size but
is differently shaped and not strongly sulcate.

GLYPTORTHIS sp. 3
Plate 43, A, figures 1-3; plate 50, D, figures 14-18

Shell small for the genus, wider than long with the hinge narrower than the
greatest width at the middle; sides and anterior margin gently rounded; anterior
commissure rectimarginate; surface finely multicostellate ; costellae numbering
about 66 to 70.

Pedicle valve with moderately convex lateral profile and broadly but fairly
strongly convex anterior profile; umbonal and median regions swollen; anterior
region somewhat flattened; posterolateral slopes short and moderately steep;
surface marked by a median costella stronger than its fellows; costellae appear
in about 4 generations. Interarea short, curved, apsacline.

Brachial valve evenly and moderately convex in lateral profile; anterior pro-
file gently convex; umbonal region somewhat swollen; umbo sulcate, sulcus

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 383

shallow and wide to a point just anterior to the middle where the sulcus dies out
and the valve is evenly convex; sulcus occupied by Io to 12 costellae.

Shell too imperfect for measurement.

Figured specimens.—116950, 116951.

Horizon and locality —Little Oak formation in Alabama: On U. S. Highway
31, 3 mile north of the bridge at Pelham, Bessemer Iron District (15’) Quad-
rangle; Bailey Gap road junction with main Cahaba Valley road, SW4SW3 sec.
13, T. 19 S., R. 2 W., 1} miles northeast of Newhope Church, Vandiver (15’)
Quadrangle.

Discussion.—Two specimens answering to the above description occur in the
collection. These shells are obviously related to G. concinnula but appear to be
more finely costellated. They may be variations of the common Little Oak species.

GLYPTORTHIS sp. 4
Plate 46, G, figures 41, 42

Shell small for the genus, wider than long; hinge about equal to the midwidth;
sides rounded; anterior commissure rectimarginate to faintly sulcate; valves
marked by 16 to 18 costellae.

Pedicle valve gently convex in lateral profile, gently convex in anterior profile
but with the median region somewhat narrowly swollen; median costella promi-
nent and forming a low fold; flanks gently swollen.

Brachial valve gently convex in both profiles; sulcus originating at umbo
widening to the anterior margin, occupied by 3 or 4 costellae; flanks gently swol-
len; interior with thin cardinal process, somewhat thickened notothyrial platform,
and stout brachiophores.

Measurements in mm.—116952a, length 2.8, brachial length 2.7, width 3.6,
hinge width 3.5, thickness 1.3.

Figured specimen.—116952a.

Horizon and locality—McLish formation (zone 45) in Oklahoma: On West
Spring Creek, sec. 6, T. 2 S., R. 1 W., Murray County.

Discussion.—The specimens of this species in the National Collection are all
small and somewhat variable. They have some characters of young specimens
of Glyptorthis. A larger collection is needed to make certain whether or not the
adult character is one of small size. The species at present cannot be related to
any known one from Oklahoma.

Genus ERIDORTHIS Foerste, 1909

Eridorthis Forrste, Bull. Sci. Lab., Denison Univ., vol. 14, p. 223, 1909.—ScHUCHERT and
Coorer, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 91, 1932.

This unusual genus which is undoubtedly an offshoot from the main stem of
Glyptorthis, is characterized by a strong development of the fold and sulcus.
Glyptorthis as a rule is generally only slightly folded, but in Eridorthis the sul-
cus is deep and the fold quite elevated. These features give the genus the ap-
pearance of Oxoplecia or Cliftonia. In making Eridorthis, Foerste emphasized

384 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the inversion of the fold and sulcus. In young Eridorthis the pedicle valve pos-
sesses a short fold and the brachial valve is sulcate, but in the adult a fold arises
from the brachial sulcus and the pedicle valve becomes deeply sulcate. This is
a common feature in many of the orthoid brachiopods. The presence of the
strong fold and sulcus is a more important generic feature than the inversion.
Hitherto Eridorthis has not been identified from rocks outside of Kentucky
and the Ohio Valley. Its range was Trenton to Eden. The presence of a well-
developed species of this genus in the Effna limestone is quite unexpected.

ERIDORTHIS INEXPECTA Cooper, new species
Plate 48, A, figures 1-6

Shell large for the genus, superficially resembling Ovoplecia. Subrectangular
in outline, wider than long, with narrowly rounded cardinal extremities. Lateral
margins broadly rounded, anterior margin broadly rounded. Surface costellate,
with 7 to 9 narrowly rounded costellae separated by spaces in width about equal
to the width of the costellae; strong concentric lamellae undulate over the cos-
tellae and are spaced about 4 to the millimeter.

Pedicle valve unevenly convex in lateral profile with the most convexity in
the posterior half, the anterior half being somewhat flattened. Beak broadly ob-
tuse, extending slightly posterior to the posterior margin. Sulcus originating
about 3 mm. anterior to the beak, widening gradually to occupy somewhat more
than a third of the width at the front. Sulcus deepening anteriorly to form a
short rounded tongue. Sulcus bounded by narrowly elevated folds raised above
the flanks which are flattened to slightly concave and slope moderately steeply
to the margins. Interarea fairly long, strongly apsacline, slightly curved, and
with a narrow, open delthyrium. Musculature like Glyptorthis.

Brachial valve moderately convex in lateral profile with the anterior third
slightly more convex and the maximum convexity at about the middle. Anterior
profile broadly convex. Umbo sulcate, sulcus shallow and short, becoming a fold
between 3 and 4 mm. from the beak. Fold low and rounded but well differenti-
ated from the flanks which are gently convex and fairly steep sided.

Measurements in mm.—

Length Width Thickness

Holotype,.(pedicle: valve) ii..)55.5..03 cee! 15.7 19.7 3.2)¢
Paratype ( “ te TT TOLOOR:) cc sre einer & 15.3 17.8 4.1
i. (brachial valve 110106e).......... 13.2 16.4 2.0
Coa Ets STTOROOD)) eres eeve are 15.1 19.1 57
" Gouss St Sprore6t) ieee 17.2 21.5 4.1
- Gist oY PLITOLOO) oa. aetreee 10.9 14.3 2.3

Types.—Holotype: 110104a; figured paratypes: 110106b-e; unfigured para-
types: I10104b,c, 110106a,f,g.

Horizon and locality.—Effna formation in Virginia: Porterfield Quarry, 5
miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle ; Edinburg for-
mation (Liberty Hall facies), 1.8 miles S. 4° W. of Bethel Church, 5.9 miles east
of Harrisonburg, Harrisonburg (15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 385

Discussion—tThis species is larger than the other two known species,
E. nicklesi Foerste and E. rogersensis Foerste, and the fold and sulcus originate
nearer the beak than in either of the other two.

Genus PTYCHOPLEURELLA Schuchert and Cooper, 1931

Ptychopleurella ScHUCHERT and Cooper, Amer. Journ. Sci., ser. 5, vol. 22, p. 244, 1031;
Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 92, 1932.

This genus is composed of a considerable number of species, all of small size.
The pedicle valve is characterized by a hemipyramidal profile and a long palin-
trope bisected by a narrow delthyrium. The delthyrium is often restricted by
lateral plates along its sides. In addition to the lateral plates the apex of the
delthyrium may be occupied by a small plate slightly depressed below the delthy-
rial edge and usually more or less concave. This plate may be the seat of pedicle
attachment and occupies the position of the pedicle scar and the pseudodeltidium
of other genera. Internally the muscle field is like that of Glyptorthis, but the
dental plates, which are of the receding type, are much reduced.

The brachial valve is generally more or less strongly convex and has all the
internal details of Glyptorthis. Generally the median ridge is more elevated and
slender than usual in Glyptorthis, and the cardinalia are ponderous for such a
small shell.

The most distinctive features of this genus are on the exterior. The pedicle
valve is always provided with a prominent median costa which may be elevated
or depressed and which usually is accompanied by 2 or 4 additional costae that
form a more or less distinct fold. Not infrequently the median costa may be de-
pressed below the level of the fold. The brachial valve is characterized by a
corresponding deep sulcus.

Ptychopleurella is not common in the rocks studied. The most prolific locality
for the genus and one yielding exquisite specimens, with proper handling, is the
Porterfield Quarry, 5 miles east of Saltville, Va. Here it occurs in the thin lime-
stone layers of the transition beds from the Effna formation to the Rich Valley
formation. Fossils in the broken pieces of limestone lying on the dumps about
the quarry are silicified, and the specimens can be etched free of the matrix,
Species not described because of insufficient material occur in the Benbolt forma-
tion at Rye Cove, Va., and at two levels in the Edinburg limestone, 4 mile
east of Strasburg Junction, Va.

PTYCHOPLEURELLA GLOBULARIS Cooper, new species
Plate 43, D, figures 9-17; plate 82, H, figures 33-39

Shell small for the genus, subrectangular in outline but with rounded angles;
unequally biconvex, the pedicle valve having about two-thirds the depth of the
brachial valve; hinge slightly narrower than the greatest shell width; sides
slightly rounded or nearly straight ; anterolateral extremities rounded; anterior
margin truncated ; anterior commissure rectimarginate to slightly sulcate; sur-
face multicostellate, costellae subangular, distant, separated by spaces about twice

386 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the width of a costella ; about 15 to 16 costellae on a valve. Lamellae strong, dis-
tant, 3 or 4 in the space of I mm.

Pedicle valve fairly strongly convex in both profiles and with the greatest con-
vexity at about the middle; median costella more prominent and more elevated
than those surrounding it; anterior end of median costella with a short costella
implanted on each side to constitute an indistinct fold; median region swollen
and with steep slopes to the margins, giving the valve as a whole a strongly
inflated appearance. Interarea gently curved; apsacline. Pedicle interior with
large teeth ; unbonal cavities filled; muscle field deeply impressed, adductor track
long, thickened, and elevated.

Brachial valve strongly convex in lateral profile with the greatest convexity in
the umbonal region; broadly convex in anterior profile with the median region
broadly indented by a low sulcus; umbo swollen ; sulcus originating at umbo and
widening to anterior margin where it makes slightly less than half the width;
sulcus occupied by 2 strong costellae; flanks bounding sulcus swollen; postero-
lateral slopes steep. Brachial interior with stout curved brachiophores; short,
thick median ridge and stout cardinal process.

Measurements in mm.—

Hinge
Length Width width Thickness
ELOLORY PEiya Fone cine & Aeeeetee hia aS otb.s 5.0 5.8 5.8 3.7
Paratype (pedicle valve 116955b)... 68 7.4 6.0 2.9
< (brachial valve 116955a).. 5.9 73 6.3 2.0

Type.—Holotype: 116955c; figured paratypes: 116954a-e, 116955a,b,d; un-
figured paratypes: 116955e-h.

Horizon and locality.—Arline formation in Tennessee: 100 yards southwest
of the Negro cemetery, 4 mile northeast of Friendsville, Concord (T.V.A.
138-SW) Quadrangle.

Discussion.—This species is characterized by its globular form and the distant
costation. The sulcus is wide and occupied by 2 costae. It is not like any of the
other species herein assigned to this genus. It somewhat resembles Glyptorthis
concinnula but is more strongly and distantly costate and the costae are less
numerous.

PTYCHOPLEURELLA GLYPTA Cooper, new species
Plate 42, F, figures 28-39

Fairly large for the genus, subrectangular in outline, wider than long; hinge
slightly narrower than the shell width at the middle; sides gently rounded; an-
terolateral extremities narrowly rounded; anterior margin truncated to emargi-
nated ; anterior commissure rectimarginate. Surface marked by 17 strong, sub-
angular costae; imbrications strong, 3 to the millimeter.

Pedicle valve semiconical in lateral profile, the surface almost flat; anterior
profile broadly and very gently convex ; umbonal region slightly swollen; median
region of anterior half depressed to form a shallow sulcus; median costa promi-
nent but depressed anteriorly below those surrounding it and shorter than the

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 387

others because it is in the reentrant of the emarginate anterior; sides bounding
sulcus gently swollen; interarea long, almost catacline.

Brachial valve fairly strongly convex in lateral profile ; anterior profile broadly
and fairly strongly convex; umbo slightly inflated; median region somewhat
swollen; umbo sulcate, sulcus deep and narrow, occupied by 2 costae; flanks
bounding sulcus strongly swollen; lateral and posterolateral slopes steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype "ii rsh aa. 5.9 5.9 8.0 7.0 4.4
Paratype (116056b)..... 4.5 4.7 6.2 5.4 2.7
‘s (116056c)..... 3.0 3.8 5.6 4.6 2.1

Types——Holotype: 116956a; figured paratypes: 116956b,d; unfigured para-
type: 116956c.

Horizon and locality—Lenoir formation (calcarenites below Mosheim lime-
stone) in Tennessee: On the southwest side of the cemetery behind Friends
Church, north corner of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—This species is abundant in a shaly bed in the sub-Mosheim cal-
carenites at Friendsville. Interiors are rare; only the brachial one has been seen,
and this presents no features unusual to the genus. Ptychopleurella glypta at-
tains an unusually large size for the genus. In this respect it differs from the
other species described herein. It is somewhat suggestive of P. porcia (Billings)
but is more coarsely ornamented.

PTYCHOPLEURELLA LAMELLOSA (Raymond)
Plate 42, C, figure 12

Orthidium lamellosum Raymonp, Amer. Journ. Sci., ser. 4, vol. 20, p. 371, 1905.
Orthidium ? lamellosum Raymonp, Ann. Carnegie Mus., vol. 7, No. 2, p. 248, pl. 36, figs. 17,
18, text fig. 24, IQII.

Types.—Paratype: Y.P.M. 2706.

Horizon and locality—Valcour formation in New York: Valcour Island,
Plattsburg (15’) Quadrangle; Chazy, Rouses Point (15’) Quadrangle; and
Crown Point, Port Henry (15’) Quadrangle.

PTYCHOPLEURELLA MEDIOCOSTATA Cooper, new species
Plate 42, E, figures 22-27

Shell small, width nearly twice the length; cardinal extremities obtuse ; lateral
margins narrowly rounded ; anterior margin deeply emarginate. Surface costate ;
a strong and wide median costa occupying the center of the pedicle valve and 7
or 8 costae marking the flanks. Interspaces V-shaped in section and about the
same width as the costae. Entire surface covered by closely crowded concentric
lamellae.

Pedicle valve hemipyramidal in lateral profile with a nearly flat to slightly
concave slope and catacline to strongly apsacline interarea. Anterior profile

388 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

broadly convex; beak prominent, pointed, median costa slightly depressed with
adjacent costae to form a shallow sulcus; flanks slightly convex but the lateral
slopes to the cardinal extremities steep. Delthyrium partially covered by a short.
depressed, concave apical plate, possibly the seat of pedicle attachment. Muscle
area subcordate in outline with prominent narrow, elongate adductor impres-
sions, a conspicuous adductor field bordered by low ridges. Adjustor impres-
sions small and located at the base of the dental plates. Teeth large, dental plates
short and receding. Pallial impressions indistinct.

Brachial valve strongly convex in lateral profile with the most convex part in
the strongly arched umbonal region. Anterior profile bilobed. Sulcus originat-
ing on the convex umbo, deep and narrow and extending to the anterior margin
which is produced into a short, sharp tongue. The 2 costae bounding the sulcus
are also depressed below the flanks which are narrowly rounded and have steep
slopes to the margins. Interarea long, curved, orthocline to anacline. Sockets
deep, brachiophores ponderous with strong cuplike thickenings of callus attach-
ing them to the lateral walls. Notothyrial cavity deep and notothyrial platform
thick, supporting a septumlike cardinal process much thickened at its anterior
end. Median ridge strong and thick.

Measurements in mm.—

Hinge
Length Width width Thickness
Holotype (pedicle valve) .......... 3.9 6.2 5.0 2.5
Paratype (brachial valve 110097b).. 4. 5.8 4.7 2.0

Types.—Holotype: 110097a; figured paratypes: 110097b-d.

Horizon and locality —Effna-Rich Valley formations in Virginia: Porterfield
Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—A structure rarely preserved in these shells appears in the speci-
mens on which this species is based. This is the small apical plate at the apex of
the delthyrium. This is slightly depressed below the margin of the delthyrium
and is attached to the sloping face of the lateral plates bordering the delthyrium.
This plate is unlike a true pseudodeltidium in its concave form and may have
been the seat of pedicle attachment. The lateral plates, possibly homologous to
deltidial plates, are fairly well developed in the specimens studied.

For comparison see P. rectangulata.

PTYCHOPLEURELLA OKLAHOMENSIS Cooper, new species
Plate 42, G, figures 40-44

Shell small, wider than long with the hinge slightly narrower than the greatest
shell width which is at the middle. Sides narrowly rounded ; front margin broadly
rounded. Surface costate, about 16 broadly angular costae with interspaces about
equal in width to the width of the costae. Entire surface regularly imbricate with
about 4 to 5 imbrications to a millimeter.

Pedicle valve hemipyramidal with a very gently convex lateral profile but a
broadly convex anterior profile. Beak and umbo smooth. Median 5 costae
slightly elevated to form a broad indistinct fold. Slopes to cardinal extremities

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 389

and sides long and gentle. Median costa slightly depressed below those surround-
ing it. Palintrope strongly apsacline to nearly procline; interarea nearly flat.

Brachial valve moderately convex in lateral profile, more so than the pedicle
valve ; anterior profile broadly convex with a depressed median area correspond-
ing to the sulcus. Umbonal region sulcate; sulcus deep at the umbo, widening
and becoming more shallow anteriorly to occupy approximately half the width
at the front margin. Sulcus occupied by 2 costae; space between the 2 costae
forming the deepest part of the sulcus and corresponding to the median costa of
the pedicle valve. Flanks moderately convex, fairly broad. Slopes to cardinal
extremities concave, short and steep.

Measurements in mm.—

Dorsal Hinge
Length length Width width Thickness
Holotype (pedicle valve) ......... 2.6 ? 4.8 4.3 1.0?
Paratype (brachial valve 110095a). ? ay 5.5 5.2? 0.8 ?

Types.—Holotype : 110095b; figured paratype: 110095a; unfigured paratypes:
I10095c-e.

Horizon and locality—McLish formation in Oklahoma: Section along and
west of U.S. Highway 77, sec. 25, T. 2 S., R. 1 E., 2 to 3 miles north of Springer,
Carter County.

Discussion.—This little species has the form and size of P. lamellosum but
differs in not possessing the deep sulcus of the pedicle valve which is a conspicu-
ous feature of the New York shell. The Oklahoma species has less costae than
the New York shell.

PTYCHOPLEURELLA PORCIA (Billings)
Plate 42, B, figures 10, 11

Orthis porcia Bitit1ncs, Canadian Nat. Geol., vol. 4, p. 439, figs. 16-18, 1859; Geol. Canada,
p. 130, fig. 58, 1863.

Clitambonites porcia (Billings) RAymMonp, Ann. Carnegie Mus., vol. 7, No. 2, p. 248, pl. 36,
figs. 15, 16, IQII.

This is a small species, finely multicostellate and finely imbricate. The lateral
margins are gently rounded and the cardinal angles obtuse. Interarea orthocline ;
delthyrium very narrow. This species has the external features of Ptychopleurella
rather than Clitambonites. Raymond states that it has a narrower “deltidium”
and spondylium than Clitambonites multicostus. However, examination of the
type specimen indicates that no deltidium is present and that the spondylium is
not visible.

Types—Holotypes: G.S.C. 1044.

Horizon and locality —St. Martin formation, Island of Montreal, Quebec,
Canada.

PTYCHOPLEURELLA RECTANGULATA Cooper, new species

Plate 42, D, figures 13-21

Shell small, subrectangular in outline ; hinge slightly narrower than the great-
est shell width; cardinal extremities obtuse; sides rounded; anterior margin

390 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

slightly emarginate. Surface of the pedicle valve marked medially by a strong,
narrow costa extending from the beak to the anterior margin and on each side
is intercalated a small costa. Median costa generally elevated above those sur-
rounding it, and the area occupied by the 2 or 3 neighboring costae is flattened.
Surface on each side of median costa marked by about 8 costae. Brachial valve
marked medianly by a deep sulcus extending from near the beak to the front
margin. Sulcus broadly V-shaped in section and occupied by 4 or 5 costae.

Pedicle valve hemiconical, with nearly flat lateral profile and slightly pro-
tuberant beak; anterior profile broadly but gently convex. Lateral slopes flat-
tened and moderately steeply inclined. Interarea catacline. Muscle field short,
not strongly thickened. Dental plates very short, receding. Apical plate only
slightly developed.

Brachial valve moderately convex in lateral profile with the greatest curvature
at the umbo; anterior profile bilobed. Flanks bounding sulcus moderately swol-
len with steep posterolateral slopes but gentle anterior and lateral slopes. Noto-
thyrial platform deep, cardinal process a simple septum; median ridge reaching
slightly anterior to the middle, fairly stout.

Measurements in mm.—Holotype, length 3.7, width 5.0, hinge width 3.9, thick-
ness 3.7.

Types.—Holotype: 110101a; figured paratypes: 110101b-e; unfigured para-
types: 110101f-k.

Horizon and locality —Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This species differs from P. mediocostata, with which it occurs,
by its less transverse outline, less emarginate anterior margin, more slender and
less depressed median costa, and the slight development of the apical plate of the
pedicle valve.

PTYCHOPLEURELLA SULCATA Cooper, new species
Plate 50,I, figures 40, 41

Species represented by two fairly well preserved specimens and a fragmentary
one. Exterior usual for the genus; pedicle valve youthful, somewhat concave in
lateral profile, broadly triangular in anterior profile; median costa prominent,
larger than the others and with 2 intercalated ribs on each side forming a median
fascicle. Flanks gently swollen and marked by 7 costae.

Brachial valve moderately convex in lateral profile with the maximum con-
vexity at the umbo; anterior profile broadly convex but with the median region
deeply sulcate; sulcus originating at the umbo, deep, and deepening to the an-
terior margin where it occupies slightly less than half the width; sulcus contain-
ing 4 costae, 2 intercalated near the beak and the other 2 at about 1 mm. anterior
to the beak. Flanks bounding sulcus narrowly but not strongly swollen; postero-
lateral slopes steep.

Measurements in mm.—

Holotypes( brachial) valve) i>: ..; acuta. 2aitince vide beink 2 6.0
Paratype (pedicle valve 110108b).......... sashpelareamimereto ni 3.3 5.5

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 301

Types.—Holotype: 110108a; figured paratype: 110108b.

Horizon and locality—Oranda formation in Virginia: 4 mile west of Stras-
burg, Strasburg (15’) Quadrangle; 0.6 mile northwest of Linville Station,
Broadway (15’) Quadrangle.

Discussion.—This species is characterized by its large size, deep sulcus, and
the manner of implantation of the costae occupying the sulcus. It is of about
the size of P. globularis but differs in having 4 costae in the sulcus rather than
2. It suggests P. uniplicata, but that species has only 2 costae in the sulcus.

PTYCHOPLEURELLA UNIPLICATA Cooper, new species
Plate 49, H, figures 41-44

Shell of about usual size for the genus, subrectangular in outline; sides nar-
rowly rounded; anterior commissure sulcate; anterior margin nearly straight.
Pedicle valve unequally convex in lateral profile, the posterior third somewhat
concave, the anterior two-thirds flattened to gently convex; median costa raised
to form a low fold; flanks flattened and sloping gently to the margins, marked
by 6 costae.

Brachial valve moderately convex in lateral profile with the maximum con-
vexity at about the middle; anterior profile broadly convex but with the median
region sulcate; sulcus deep and wide, occupied by 2 costae intercalated about
I mm. anterior to the beak; flanks bounding sulcus fairly strongly convex ; pos-
terolateral slopes steep.

Measurements in mm.—

alot pe .Cnedicle Walwe ELIOT 10a ) «:0's.s, hae aia spun: a aqe’gis 0 Meete 5.2 7.2
Paratype (uractial valve LEOLIOD) .. Acc nas sae ene one anre 3.7 4.7

Types.—Holotype: 110110a; figured paratype: I10110b.

Horizon and locality.—Benbolt formation in Virginia: 14 miles west of Rye
Cove, Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—This species is suggestive of P. sulcata from the Oranda forma-
tion of Virginia, but the pedicle valve is more convex and the brachial valve has
only 2 costae occupying the sulcus. The species is uncommon in the Benbolt
formation.

Family ANOMALORTHIDAE Ulrich and Cooper, 1936

Orthacea having a sessile spondylium.

Genus ANOMALORTHIS Ulrich and Cooper, 1936

Anomalorthis Utricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 622, 1936; Geol. Soc.
Amer. Special Pap. 13, p. 126, 1938.

This genus is fairly common in the upper part of the Pogonip formation in
Nevada and the Swan Peak formation of Utah. In Oklahoma Anomalorthis is
abundant in the Oil Creek formation which is the correlate of the high Pogonip.
It is also known from an undescribed species from the Joins formation of Okla-
homa. This species is considerably coarser in its costellation than the Oil Creek
species.

392 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ANOMALORTHIS LONENSIS (Walcott)

Orthis lonensis Watcort, U. S. Geol. Surv. Mon. 8, p. 74, pl. 11, figs. 6, 6a, 1884.
Anomalorthis lonensis (Walcott) UtricH and Cooper, Geol. Soc. Amer. Special Pap. 13,
p. 127, pl. 21E, figs. 18, 22-25, 27, 1938.

Types—Holotype: 17232; hypotypes: 91281a-d; figured specimen : 91280.

Horizon and locality —Upper Pogonip group in Nevada: At Lone Mountain,
18 miles northwest of Eureka, Roberts Mountains (1°) Quadrangle.

Swan Peak formation in Utah: 1 mile west of Ibex, in Smooth Canyon, Con-
fusion Range, Millard County.

ANOMALORTHIS NEVADENSIS Ulrich and Cooper
Plate 78, B, figures 10-12

Anomalorthis nevadensis ULricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 127,
pl. 21D, figs. 13-17, 1938.

Types.—Holotype: 92853c ; paratypes: 92853a,b.

Horizon and locality—Upper Pogonip group in Nevada: At west base of
Lone Mountain, 18 miles northwest of Eureka; Ikes Canyon, east side Toquima
Range, Roberts Mountains (1°) Quadrangle. North end Ely Springs Range,
Highland (15’) Quadrangle. Pogonip Ridge, White Pine District.

ANOMALORTHIS OKLAHOMENSIS Ulrich and Cooper
Plate 78, C, figures 13-20

Anomalorthis oklahomensis Utricnw and Cooper, Journ. Paleont., vol. 10, No. 7, p. 622, 1936;
Geol. Soc. Amer. Special Pap. 13, p. 128, pl. 22A, figs. 1-6, 1938.

Subpyramidal in profile and with the pedicle valve having a greater depth than
the brachial one ; hinge about as wide as the width at the middle or slightly less;
multicostellate, costellae fine, rounded, subequal, 3 to 5 in the space of 1 mm. at
the front margin of a valve 11 mm. long.

Pedicle valve hemipyramidal with a strongly procline interarea often slightly
convex outward ; umbonal region gently convex but front median part depressed
to form a conspicuous sulcus; lateral profile nearly flat; anterior profile steeply
rounded. Flanks bounding sulcus convex; slopes to the cardinal margin slightly
concave.

Brachial valve gently convex in lateral and anterior profiles ; umbo and median
region marked by a shallow, narrow sulcus; median region swollen; slopes to
the cardinal extremities short and moderately steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Lectotype (pedicle valve) ........ 7.9 ? 13.8 13.7 5.6
Paratype (pedicle valve 92854e).. 12.5 ? 16.8 19.0 ? 5.7?
+f (brachial valve 92854b). ? 10.7 13.4 11.8 ? 231?
Hypotype( “ Sue ORR DS fae 17.6 21.0 z ?

Types.—Lectotype: 92854a; figured paratypes: 92854b, 92855, 110182; un-
figured paratypes : 92854c-e.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 393

Horizon and locality—Oil Creek formation in Carter County, Okla.: Along
Henryhouse Creek; on U. S. Highway 77, sec. 25, T. 2 S., R. 1 E., 2 to 3 miles
north of Springer; north end of Criner Hills. In Murray County, Okla.: in
NE} sec. 22, T. 2 S., R. 1 E., 4 to 5 miles due north of Glenn; along the road 2
miles southwest of Nebo; second dam on Spring Creek; 1 mile northwest
of Hickory ; section on Falls Creek. In Johnston County, Okla.: on west branch
of Sycamore Creek, sec. 27, T. 3 S., R. 4 E.; middle of the south side sec. 34,
T.2N., R. 6 E., 1 mile southwest of Franks.

Discussion.—This species is abundant throughout the Oil Creek formation in
Oklahoma. It is a somewhat variable species, and collection of better or more
material may see the splitting out of additional species. It is a fact that to
date no specimens have been collected with both valves together. It is usually
found as scattered valves in bryozoan debris or in coarse calcarenite, both the
products of strongly agitated waters.

ANOMALORTHIS UTAHENSIS Ulrich and Cooper

Anomalorthis utahensis UtricH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 622, 10936;
Geol. Soc. Amer. Special Pap. 13, p. 129, pl. 22 C, figs. 11-13, 16, 17, 19-24, 1938.

Types.—Holotype: 91284; paratypes: 91283a-f ; 91286.
Horizon and locality—Swan Peak formation in Utah: Smooth Canyon, I
mile west of Ibex, Confusion Range. Kanosh shale in western Utah.
Upper Pogonip group in Nevada: On west side Snake Range, 25 miles south
of Osceola.
Family DINORTHIDAE Schuchert and Cooper, 1931

Progessive Orthacea having a subquadrate muscle field in the pedicle valve,
Orthis-like brachiophores, and a simple cardinal process with crenulated
myophore.

Genus DINORTHIS Hall and Clarke, 1892

Dinorthis Hatt and CLARKE, Pal. New York, vol. 8, pt. I, pp. 195, 222, 1892—-SCHUCHERT
and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 93, 1932.

DINORTHIS ATAVOIDES Willard
Plate 57, A, figures 1-11
Dinorthis atavoides WiLLarD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 270,
pl. 2, fig. 4, 1928—Butts, Virginia Geol. Surv. Bull. 52 pt. 2, p. 43, pl. 73, figs. 55-61,
1942.

Shell fairly large for the genus, length about one-third less than the width;
greatest width at about the middle; cardinal extremities obtuse, rounded. Lateral
margins moderately rounded, anterior margin gently rounded to truncated. An-
terior commissure gently and broadly uniplicate. Valves unequally convex, the
brachial valve having the greater depth and convexity. Length of hinge slightly
exceeding the valve length. Surface marked by 30 to 36 elevated and narrowly
rounded costae separated by spaces equal to or slightly wider than the costae.
No bifurcations observed. Median costae largest and widest spaced.

394 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve very gently to moderately convex in lateral profile, gently con-
vex in anterior profile. Umbonal region moderately swollen and continued an-
teriorly to about the middle of the valve as a low, wide, and poorly defined fold.
Posterolateral slopes gently concave. Anterior median half depressed into a
shallow, wide sulcus; anterolateral areas very gently convex to flat. Interarea
short, curved, apsacline. Beak scarcely protruding beyond the brachial beak.

Brachial valve evenly and moderately convex in lateral profile, the greatest
convexity located about at the middle; strongly convex in anterior profile. Pos-
terolateral slopes steep; anterior and anterolateral slopes moderately steep.
Median and anteromedian regions swollen. Interarea short, apsacline. Beak
curved over pedicle interarea. Sulcus narrow and indistinct on umbo, narrow
and shallow anteriorly or absent.

Pedicle muscle field slightly longer than wide; adductor track narrow; diduc-
tor impressions wide, not elongated noticeably anterior to the front of the muscle
field. Brachial cardinalia characterized by delicacy and compactness for such
large shells. Median ridge short, adductor field small.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (110283k)........ 17.7 17.8 24.6 17.3 8.5
: (o8216a)).). .2:d. ser 19.5 19.6 26.5 ? 10.2
ee GOSS) okie ee. 17.0 17.2 23.0 16.2 8.2

Types.—Holotype: M.C.Z. 8605; figured paratype: M.C.Z. 8606; figured
hypotypes: 98215 (figured by Butts, 1942), 98216a, 110283e,¢,k; unfigured
hypotypes: 110283a-d,f,h-j, I-n.

Horizon and locality—Lincolnshire formation in Tennessee: $ mile northwest
of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle; Oakman; on shore of a
small point in Norris Reservoir, 4 mile south-southeast of Oakman Tunnel,
Dutch Valley (T.V.A. 154-SE) Quadrangle; ridge paralleling the railroad,
Maloneyville, John Sevier (T.V.A. 146-SE) Quadrangle; 90 to 120 feet above
the ‘““Mosheim” limestone on U. S. Highway 25E, 1 mile north of Indian Creek,
Howard Quarter (T.V.A. 162-NW) Quadrangle; $ mile southwest of Mount
Eager Church, 0.2 mile north-northwest of the main road, Hogskin Valley,
Powder Springs (T.V.A. 154-SW) Quadrangle.

Lincolnshire formation in Virginia: North of Copper Creek between Speers
Ferry and Clinchport, Clinchport (T.V.A. 188-NW) Quadrangle; Marcem
Quarry, 2 miles west of Gate City, Gate City (T.V.A. 188-NE) Quadrangle ;
Templeton Branch, 5 miles northwest of Gate City; Speers Ferry, Clinchport
(T.V.A. 188-NW) Quadrangle; 1.8 miles S. 4° W. of Bethel Church, Harrison-
burg (15’) Quadrangle; 14 miles northwest of Oakwood; on Virginia Highway
100 just north of junction with Highway 42, Staffordsville, Giles County ; north-
west slope of Sinking Creek, 24 miles southwest of Huffman; about 200 feet
east of Whistle Creek bridge on U. S. Highway 60 and 1,200 feet north of the
highway, 14 miles northwest of Lexington, Lexington (15’) Quadrangle; branch
of Moccasin Creek, 3 mile south-southwest of Tumbez, Moll Creek (T.V.A.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 395

196-SE) Quadrangle; Hoge Farm, 13 miles due east of Central Church, Burkes
Garden (15’) Quadrangle.

“Lenoir” formation in Alabama: 7 to 11 feet above the ‘““Mosheim” limestone,
Clifton Terrace section, Birmingham, Birmingham (30’) Quadrangle.

Discussion—This species can be readily recognized by its direct, unbifurcated
costae and its thick, robust appearance. The posterior portion of both valves is
quite deep, and the front part of the pedicle valve is not strongly sulcate. The
species suggests a large form of D. holdeni from which it may be descended.
There are, however, important differences between the two. Dinorthis holdeni
is a smaller species which is in general not quite as wide as D. atavoides and is
differently proportioned. The front part of the pedicle valve is more depressed
and the valve comparatively shallower than that of D. atavoides.

Dinorthis willardi also suggests the species in question by its direct and un-
bifucated costae, but it is much more slender in lateral profile and the pedicle
valve is more concave and more shallow while the brachial valve is not so deep
as the same valve in D. atavoides.

DINORTHIS HOLDENI (Willard)
Plate 57, C, figures 14-28

Plectorthis holdeni Witiarp, Bull. Mus. Comp. Zool. Harvard Coll., vol. 68, No. 6, p. 262,
pl. 1, fig. 5, 1928.

Shell small for the genus, wider than long with the greatest width at about
the middle; cardinal extremities obtusely rounded. Lateral margins evenly
rounded, front margin truncated. Anterior commissure gently uniplicate to
nearly straight. Valves convexi-concave. Hinge width slightly greater than the
valve length. Surface marked by 30 to 33 narrowly rounded costae having inter-
spaces equal to or greater than the width of the costae. Costae of median region
more widely spaced and somewhat larger and wider than those on the flanks.

Pedicle valve with umbonal region somewhat narrowly swollen and forming
the only strongly convex portion of the valve; posterolateral slopes gently con-
cave. Beak prominent. Lateral profile with posterior half convex but an-
terior half gently to moderately concave. Anterolateral areas flattened. Inter-
area moderately long, strongly apsacline to almost catacline in position.

Brachial valve with lateral profile unevenly convex and with the maximum
convexity located just posterior to the middle. Umbonal region marked by a
shallow and narrow sulcus extending, more or less well defined, to the anterior
margin. Median and anterolateral areas gently swollen; posterolateral slopes
gentle. Interarea short, nearly orthocline. Cardinal extremities deflected toward
the brachial valve.

Interior: Muscle area of pedicle valve nearly square, pallial trunks short, ap-
pearing as raised ridges having the usual course for the genus. Median ridge of
brachial valve extending for about one-third the length; adductor field small.

396 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (110302b)......... 14.1 14.3 18.9 14.8 5.7
sf (#103022)! NUS 5 13.8 14.7 18.2 14.4 6.6
(r10302c) te yet 8.8 8.8 re 9.5 3.8

Types.—Holotype M.C.Z. 8595; figured hypotypes: 110301b-d, 110302a,
110304d-g, 110309a; unfigured hypotypes: I1030I1a, 110302b,c, 1I10304a-c,
I10309b-g.

Horizon and locality.—Elway formation (blocky chert of Cooper and Prouty)
in Tennessee: Along U. S. Highway 25W, 4.7 miles south of Clinton, Powell
Station (T.V.A. 137-SE) Quadrangle; Evans Ferry section, on U. S. Highway
25E about 1 mile north of Indian Creek, Howard Quarter (T.V.A. 162-NW)
Quadrangle ; 4 mile northeast of Eidson, Kyles Ford (T.V.A. 170-SE) Quad-
rangle.

Elway formation (blocky chert of Cooper and Prouty) in Virginia: Speers
Ferry, Clinchport (T.V.A. 188-NW) Quadrangle; on the road to Mountain
Lake at the road fork, 4 mile north of the highway, at base of mountain, 14 miles
northwest of Newport, Giles County; road cut on Route 64, 4 mile north of
Dickensonville, Hansonville (T.V.A. 205-SW) Quadrangle; 1 mile north of
Belfast Mills, Saltville (T.V.A. 212-NE) Quadrangle; on the road along Purga-
tory Creek, 15 miles southwest of the Dunkard Church, 6 miles north of Bu-
chanan, Natural Bridge (15’) Quadrangle; Sinking Creek in Giles County, Io
miles north of Blacksburg; northwest side of knoll, 1 mile west of old Rosedale,
Russell County; east of Moccasin Creek on Virginia County Road 679, 3 mile
south of Tumbez, Moll Creek (T.V.A. 196-SE) Quadrangle; 1.2 miles south-
west of Collierstown, Rockbridge County; road from Gate City to Hills Station,
1 mile north of Copper Creek, Scott County.

Whistle Creek formation in Virginia: Along Whistle Creek, 14 miles north-
west of Lexington, Lexington (15’) Quadrangle; on Virginia County Road 602,
53 miles S. 82° W. of Middlebrook, Augusta County.

Discussion.—This species suggests a small variety of D. atavoides in general
configuration of the valves but is smaller and less robust. In lateral profile the
brachial valve of D. holdeni is not evenly convex, and the pedicle valve is gen-
erally more concave anteriorly than is true of specimens of D. atavoides. The
latter is also a proportionately wider species than D. holdeni.

DINORTHIS INTERSTRIATA Willard

Dinorthis pectinella Hatt (not Emmons), 2nd Ann. Rep. New York State Geol., pl. 34,
figs. 39-40, 1883. HALL and CLARKE, Pal. New York, vol. 8, pt. 1, pl. 5, figs. 27, 28, 1893.
D. interstriata WILLARD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 270, 1928.

This species is distinguished by its author from D. pectinella (Emmons) by
the presence of a fine rib or costella between each pair of larger ones. The type
specimen is from the Trenton of New York, but Willard identifies the species
in the Virginia ‘“Ottosee.” It has not been identified in the National Collections.

Type.—Holotype: A.M.N.H. 692 (larger specimen).

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 397

Horizon and locality —“Ottosee”’ = Benbolt? in Virginia: Fugates Hill, Bris-
tol (30’) Quadrangle. Trenton limestone in New York: On Dry Sugar River,
Lewis County.

DINORTHIS SWEENEYI (N. H. Winchell)
Plate 57, B, figures 12, 13; plate 65, C, figures 13-17

Illustrations of this species have been introduced to show the presence of a
pseudodeltidium in the genus and also to show the variability of the ribbing.
The occurrence of the pseudodeltidium is sporadic but is well known in the
Minnesota species. Of Appalachian species only D. willardi shows this structure.
Many of the species of the Appalachians do show intercalated costae along the
margins, particularly in the vicinity of the posterolateral extremities. Dinorthis
sweeneyi is usually without intercalated ribs, but a few specimens, such as the
old adult figured herein (pl. 65), show them.

Figured specimens.—48861, 118020a.

Horizon and locality—Decorah formation (Ion member) in Minnesota: At
St. Paul; and Cannon Falls, Goodhue County.

DINORTHIS TENUIS Cooper, new species
Plate 72, A, figures 1-5

Shell fairly large for the genus, wider than long ; hinge narrow; sides rounded ;
anterior margin broadly rounded; anterior commissure rectimarginate; surface
costate, costae numbering about 38, undivided and primary.

Pedicle valve with unevenly convex lateral profile, the umbonal region gently
convex but the valve anterior to the umbo moderately concave ; maximum con-
cavity in the anterior half; anterior profile broadly and gently concave. Umbonal
region gently swollen; beak small; sides somewhat flattened. Interarea short,
nearly catacline.

Brachial valve moderately convex in lateral profile, broadly and gently con-
vex in anterior profile; median region somewhat swollen ; lateral slopes long and
gentle; anterior half marked medianly by a shallow, narrow, and poorly defined
sulcus.

Measurements in mm.—Holotype, length 16.2, brachial length 16.4, width
24.6, thickness 4.7.

Type—Holotype: 116974.

Horizon and locality—Sevier formation in Tennessee: On the east side of
the road, 2.7 miles S. 7° W. of Athens, Athens (T.VA. 125-NE) Quadrangle ;
basal 2 feet of argillaceous nodular limestone 100 feet above the Meadow marble
in a glade 3 mile N. 10° E. of Meadow Station, Meadow (T.V.A. 139-NW)
Quadrangle ; Marysville road, 2 miles southeast of Friendsville, Binfield (T.V.A.
139-NE) Quadrangle; cobbly layer in Sevier, $ mile north of Meadow, Meadow
(T.V.A. 139-NW) Quadrangle.

Tellico formation in Tennessee: 1.6 miles south-southwest of Toqua School,
Vonore (T.V.A. 139-SW) Quadrangle.

398 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion.—This species is characterized by its slender profile and trans-
verse form. It is very close to D. willardi but differs in its more transverse out-
line, more concave pedicle valve, and much less convex brachial valve.

DINORTHIS TRANSVERSA Willard
Plate 58, B, figures 4-10; plate 58,C, figures 11-27; plate 268, J, figures 45-47
Dinorthis transversa WILLARD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 271,
pl. 2, figs. 1, 2, 6, 1928—Butts, Virginia Geol. Surv., Bull. 52, pt. 2, p. 83, pl. 85, figs.
14-16, 1942.
Dinorthis quadriplicata WILLARD, idem, p. 271, pl. 1, fig. 13; pl. 3, figs. 5, 6, 1928.

Species variable, outline subrectangular, width greater than length, greatest
width at about the middle. Cardinal extremities rounded, varying from nearly
a right angle to obtuse. Lateral margins broadly rounded, generally sloping
slightly toward the center ; front margin nearly straight: anterolateral extremities
somewhat narrowly rounded. Anterior commissure broadly uniplicate. Sur-
face multicostate ; median 4 to 6 costae generally stronger than the others and
usually unbifurcated in young parts of the shell. Costae on the flanks usually
bifurcated near their midlength, but on old or large specimens additional bifurca-
tion takes place near the front margin creating 3 generations of costae. Some
specimens show bifurcation of the larger median costae at the front.

Pedicle valve in anterior profile gently to moderately concave; in lateral pro-
file umbonal region more or less strongly convex, while the front two-thirds are
moderately to strongly concave. Swollen umbonal region short; median strong
costae often indistinctly define a poorly developed fold at least in the posterior
half. Interarea short, nearly procline. Flanks varying from concave to flat or
very gently convex.

Brachial valve moderately convex in lateral profile with the greatest convexity
at about the middle; anterior profile moderately to strongly rounded, often with
a moderately strong median depression. Sulcus originating at the beak, moder-
ately to strongly impressed and generally extending to the anterior margin where
it usually is shallower than on parts posterior to the margin. Flanks bounding
sulcus narrowly swollen. Posterolateral slopes generally steep. Interarea short,
orthocline.

Pedicle valve with muscle area slightly wider than long, tapering slightly pos-
teriorly. Adductor field large, nearly circular. A slight elevation separates an-
terior ends of diductor impressions. Median ridge of brachial valve not quite
reaching center, cardinalia small.

Measurements in mm.— Bdciaat Hinge

Length length Width width Thickness
EMEHLGEV IDOE Lave, 7a cin slaps eishalsiamecea lee 20.7 212 30.6 22.0 ?
Hypotype (110332a) ......... 17.4 18.1 23.9 21.2 6.7
Holotype (D. quadriplicata).. 19.7 ? 24.9 18.5 ? ?
Hypotype (98038)........... 17.4 18.5 25.1 17.3 6.8
A (TT OZ2O Vives tis slob fe 13.0 14.1 19.7 172 3.9
: CU UOGIE) oa ane Siriaas 20.5 21.8 30.4 22.0 8.9

od CITTOOA ye. sss 20.6 21.4 30.0 24.9 7.6

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 399

Types.—Holotype: M.C.Z. 8603; figured paratype: M.C.Z. 8604; figured
hypotypes: 110370, 111799, 111800a,b, 116975, 116976a,b,c, 116977, 118024a,b ;
unfigured paratypes: 98030, 110332a, 116800c,d. Holotype of D. quadriplicata:
M.C.Z. 8602 ; figured hypotypes : 116976a,b, measured hypotypes : 98038, 110320.

Horizon and locality—Benbolt formation in Tennessee: 30 feet above the
“Stones River” 100 yards west of the store at junction of Tennessee Highway
33 and the Flint Creek road, Maynardville (T.V.A. 145-SE) Quadrangle; Win-
stead Post Office (Shagtown), Anderson County ; Raccoon Valley, 18 miles north
of Knoxville; Evans Ferry, north of Indian Creek on U. S. Highway 25E,
Howard Quarter (T.V.A. 162-NW) Quadrangle; Tennessee Highway 33 at
Nicely and Palmer’s store, 4 mile east of Kate, Maynardville (30’) Quadrangle ;
head of Flint Creek, 14 miles northeast of Acuff, Powder Springs (T.V.A.
154-SW) Quadrangle; 1 mile west of Lone Mountain, Tazewell (T.V.A.
154-NE) Quadrangle; 14 miles northeast of Lone Mountain, east of Ball Creek
on the road to Tazewell, Tazewell (T.V.A. 154-NE) Quadrangle; 1 mile south-
east of White Horn, Bulls Gap (T.V.A. 171-SE) Quadrangle; north side of
the highway, 1.6 miles northeast of Lee Valley (T.V.A. 171-NW) Quadrangle ;
west side of the sharp loop of the road down Flint Creek, NW4 center subquad.,
Powder Springs (T.V.A. 154-SW) Quadrangle.

Benbolt formation in Virginia: At Fugates Hill, north of Mendota, Bristol
(30’) Quadrangle; 0.2 mile south of the middle fork of Moccasin Creek, 14
miles due south of Hansonville, Hansonville (T.V.A. 205-SW) Quadrangle ;
Brick Church 14 miles southwest of Rye Cove, Clinchport (T.V.A. 188-NW)
Quadrangle; 5 miles north of Wytheville, Wythe County; south side of Mount
Hagan School, southeast corner of the NE. subquad., Hilton (T.V.A. 197-NW)
Quadrangle; 1 mile east of Hansonville, Hansonville (T.V.A. 205-SW) Quad-
rangle; 4 mile south of Gate City, Gate City (T.V.A. 188-NE) Quadrangle ;
north side of U. S. Highway 19, 1 mile due north of Belfast Mills, Saltville
(T.V.A. 212-NE) Quadrangle; Speers Ferry, Clinchport (T.V.A. 188-NW)
Quadrangle; just east of Meridian 17’30”, east of Moccasin Creek, north edge
of Mendota (T.V.A. 197-NW) Quadrangle; 4 mile east of Cedar Point School,
Hilton (T.V.A. 197-NW) Quadrangle; 4 mile southeast of Green Valley
Church, Brumley (T.V.A. 205-SE) Quadrangle; 4 mile southeast of Richpatch,
Eagle Rock (15’) Quadrangle; north side of U. S. Highway 19, 13 miles south-
east of Hansonville, Brumley (T.V.A. 205-SE) Quadrangle; Virginia Highway
74, 54 miles east of its junction with U. S. Highway 54 (Tennessee 71), Hilton
(T.V.A. 197-NW) Quadrangle; vicinity of Rye Cove, Clinchport (T.V.A.
188-NW) Quadrangle ; sandstone 4 mile southeast of Mooney Cemetery, 1 mile
north-northwest of Otes, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Edinburg formation (Nidulites zone) on Strasburg (15’) Quadrangle, Vir-
ginia: In a field on the east side of U. S. Highway 11, 14 miles north of Stras-
burg ; Edinburg formation (upper part Cyrtonotella beds), along Tumbling Run,
1% miles southwest of Strasburg; ravine at switch about } mile east of Strasburg
Junction.

400 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Shippensburg formation (Pinesburg member) in Maryland: At Wilson on
U. S. Highway 40, west side Conococheague Creek, 7 miles west of Hagerstown,
Williamsport (15’) Quadrangle.

Shippensburg formation (Pinesburg member) in Pennsylvania: In field on
north side of railroad, 2} miles southwest of Marion, Chambersburg (15’)
Quadrangle.

Sevier formation (sandstone No. 5 of Neuman) in Tennessee: 0.57 mile
southwest of Rock Branch, Kinzel Springs (T.V.A. 148-NE) Quadrangle.

Discussion.—In general this species is characterized by its transverse form in
most of the examples observed and by the bifurcation of the ribs particularly on
the flanks. Dinorthis quadriplicata is regarded as a synonym of D. transversa,
perhaps as one end member of a variable species. The type specimen of D. quad-
riplicata differs from the average specimen of D. transversa in being less wide
proportionately and in having the median costae strong and unbifurcated. Many
specimens in the collection are intermediate between this form and the type of
D. transversa, which is quite wide and in which the median costae show some
bifurcation. As most of the specimens lie between these two extremes it is be-
lieved D. transversa and D. quadriplicata belong to the same species.

The species is a very variable one showing extremes of ornamentation as well
as of outline. The costae of the flanks in general always show some bifurcation.
The large costae of the median region of both valves may or may not show
bifurcation, but more specimens do show it than not.

DINORTHIS TRANSVERSOIDES Cooper, new species
Plate 61, FE, figures 23-28

Small, attaining about half the size of D. transversa which it resembles ; pedicle
valve nearly flat in lateral profile but with the umbonal region slightly swollen ;
anterior profile nearly flat; sides rounded, anterior margin truncated; median
region nearly flat; anteromedian area gently sulcate and occupied by a fascicle
of costae larger than those on the bounding areas; flanks very gently convex;
posterolateral areas deflected slightly toward the brachial valve.

Brachial valve strongly convex in lateral profile with the greatest convexity
in the median region; anterior and posterior slopes steep and nearly equal in
length ; anterior profile strongly convex; umbo sulcate, sulcus originating at the
beak and extending to the anterior margin, narrow and shallow throughout its
length ; flanks bounding sulcus and lateral slopes inflated ; posterolateral extremi-
ties swollen.

Measurements in mn.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve) ............ 2.7. ? 16.0 12.9 ?
Paratype ( “ 4 DLOSATA) ec cre 12.6 ? 17.5 15.2 ?
i (brachial valve 11034Ic).... ? 13.0 16.3 12.4 a7.

pA, Aaa ty inal Foal ie 12.6 16.2 12.7 3.9

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 401

Types—Holotype: 110341b; figured paratypes: 110341a,c,d.

Horizon and locality—Dryden formation in Tennessee: I mile west of Lone
Mountain, Tazewell (T.V.A. 154-NE) Quadrangle.

Discussion—In ornamentation and outline this species is very much like
D. transversa but it differs in having a much more convex brachial valve. Young
specimens of D. transversa comparable to the adults of D. transversoides have
a much less convex brachial valve than that of the latter species.

DINORTHIS VENUSTA Cooper, new species
Plate 58, A, figures 1-3; plate 71, H, figures 41-50

Shell of about medium size for the genus, wider than long; subrectangular in
outline ; cardinal extremities obtuse; sides broadly rounded ; anterior somewhat
truncated; anterior commissure broadly uniplicate; surface strongly costate,
about 34 on a large specimen ; costae narrowly rounded in the young stages but
becoming broad and low anteriorly.

Pedicle valve unevenly convex in lateral profile; the posterior half gently con-
vex but the anterior half flattened; anterior profile flat; umbonal region gently
swollen in the posterior half; anterior half gently depressed to form a faint but
wide sulcus ; lateral areas flattened except for the posterolateral extremities which
are deflected slightly toward the brachial valve; interarea short, strongly apsa-
cline ; muscle field small but of the usual shape for the genus.

Brachial valve strongly convex in lateral profile with the maximum convexity
in the median region; anterior profile strongly convex with the median region
swollen and the lateral slopes steep ; umbonal region well rounded ; median region
inflated ; sulcus originating just anterior to the umbo, shallow and poorly defined
to a point just anterior to the middle where it is elevated to form an ill-defined,
broad fold ; lateral slopes steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EVOLGEY Pe hres e s's os.c 18.6 19.1 24.3 18.6 9.0
Paratype (110286b).. 16.7 16.4 20.9 16.0 7.5

Type.—Holotype: 110286a ; figured paratypes: 110286b, 116978a-c.

Horizon and locality—Shaly bed in upper Red Knobs formation in Tennessee:
2 miles southeast of Kiser, Meadow (T.V.A. 139-NW) Quadrangle; 3 miles
northwest of Madisonville, near fault, Sweetwater (T.V.A. 131-SW) Quad-
rangle.

Discussion.—This species is characterized by its compact, subrectangular out-
line and the strong costae. It is very similar to D. atavoides in its exterior de-
tails, but there are nevertheless many differences. D. venustus has a flatter
pedicle valve which is not medianly inflated as in D. atavoides. Furthermore, the
sides of the Red Knobs species are flatter and the sulcus is somewhat broader
and more poorly defined. Dinorthis venustus is a less transverse shell than
D. atavoides. The profiles of the brachial valves are similar, but that of D. venus-

402 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

tus is stronger in both lateral and anterior directions. The sulcus of the brachial
valve of D. atavoides is stronger than that of D. venusta.

DINORTHIS VIRGINIENSIS Cooper, new species
Plate 59, B, figures 17-21

Shell unusually large for the genus, subrectangular in outline with the length
less than the width; hinge narrow; cardinal extremities obtusely rounded; sides
broadly rounded; front margin broadly truncated; surface multicostate, costae
numbering about 4 in 5 mm. at the front margin.

Pedicle valve nearly flat to gently concave with the most concave part in the
median region ; umbonal region gently convex; fold originating at the umbo, low
and inconspicuous throughout its length to the front margin; fold a narrow
median fascicle of 3 primary costae expanding and increasing anteriorly by
bifurcation and implantation. Flanks bounding fold gently concave; lateral and
posterolateral regions flat. Interarea short, apsacline. Interior with long, sharply
defined muscle field longitudinally rectangular in outline but with the anterior
margin deeply indented ; adjustor scars prominent ; diductor scars long, oblique,
sharply pointed at the anterior ends; adductor ridge elevated ; pallial marks not
strongly impressed.

Brachial valve fairly strongly convex in lateral profile with the maximum con-
vexity at about the middle ; anterior profile strongly and broadly convex, with the
top somewhat flattened but with short, steep slopes to the sides; broadly sulcate ;
flanks bounding sulcus swollen; posterolateral slopes short and steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holott be: is cammcs’ oy) Jeatavanl up ot. « 29.9 30.4 38.7 29.0 115+
Paratype (pedicle valve 116980b).... 26.0 ? 34.0 29.0 ? iy

Types.—Holotype: 116979; figured paratypes: 116980a,b; unfigured para-
types: 116980c,d.

Horizon and locality—Edinburg formation (50 to 75 feet above cherty bed
of Lincolnshire) in Virginia: From a quarry on the north side of U. S. Highway
33, I mile west of the junction with Virginia Highway 613, 4 miles west of Dale
Enterprise, Harrisonburg (15’) Quadrangle ; 500 to 600 feet above the “Lenoir”
on Colliers Creek on Virginia Highway 251, $ mile north of the junction with
Virginia Highway 612, 6 miles west-southwest of Lexington, Rockbridge County.

Discussion.—This is the largest species of Dinorthis at present known. The
ornamentation of the pedicle valve indicates clearly that it is related to D. trans-
versa. It differs in its great size and much less transverse outline.

DINORTHIS WILLARDI Cooper, new species
Plate 59, A, figures 1-16

Shell large for the genus, wider than long with obtusely rounded cardinal ex-
tremities and broadly rounded lateral and anterior margins. Anterior commis-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 403

sure broadly arched toward the brachial valve. Hinge width equal to about two-
thirds the width. Brachial valve shallow. Pedicle valve flattened, giving the
species a compressed appearance. Surface marked by simple, unbifurcated costae,
about 36 in number. Interspaces generally wider than the width of the costae,
which are narrowly rounded to subcarinate.

Pedicle valve with narrowly swollen umbo occupying the posterior quarter
and a prominent narrow beak ; posterolateral slopes nearly flat and broad, vary-
ing to slightly convex where the cardinal extremities are bent toward the brachial
valve. Median and anteromedian portions nearly flat to gently concave. Antero-
lateral areas nearly flat. Interarea very short, varying from apsacline to nearly
procline.

Brachial valve moderately convex in lateral profile with the greatest convexity
located in the posterior half; sulcus variable, when present originating at the beak
and extending to the anterior margin where it is nearly merged in the general
convexity. Sulcus usually occupied by 2 or 3 costae. Median half of valve gently
swollen ; posterolateral slopes moderately steep; anterior slope gentle; cardinal
extremities deflected slightly toward the brachial valve. Interarea apsacline,
arched over pedicle valve interarea.

Interior with pedicle muscle area small and brachial cardinalia delicate for such
a large species.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FEGOLY PE aks. oh geieiss 20.0 20.6 27.6 19.6 6.0
Paratype (116981a).. 24.7 26.2 35.3 27.3 6.2
9 (116981b).. 23.0 24.0 33.0 24.2 5.4

Types.—Holotype: 116981c; figured paratypes: 116981a,b, 116982a, 116983b,
c, 117988a; unfigured paratypes: 116981d, 116982b, 116983a, 117988b-e.

Horizon and locality—Lincolnshire formation (Hogskin member) in Tennes-
see: I mile southeast of Washburn, Dutch Valley (T.V.A. 154-SE) Quadrangle;
10 miles north of Knoxville and 2 miles northeast of Hall Crossroad, Fountain
City (T.V.A. 146-SW) Quadrangle; 1 mile north of Wilson Post Office, Brice-
ville (30’) Quadrangle; 2 miles southwest of Hall Crossroad, northwest quarter
center subquad., Fountain City (T.V.A. 146-SW) Quadrangle; Sally Cleve-
land Farm, ? mile southwest of Washburn, Dutch Valley (T.V.A. 154-SE)
Quadrangle; Evans Ferry, U. S. Highway 25F, # mile north of Indian Creek,
Howard Quarter (T.V.A. 162-NW) Quadrangle; south of first bridge north of
Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle ; southwest quarter of the
northwest subquad; 0.4 mile east of Red Hill, Avondale (T.V.A. 162-SW)
Quadrangle on road to Thorn Hill; 2.1 miles southwest of Mount Eager Church,
Hogskin Valley, Powder Springs (T.V.A. 154-SW) Quadrangle.

Same formation in Virginia: 1 mile west of Rye Cove; Speers Ferry; 4 mile
northeast of Speers Ferry, Clinchport (T.V.A. 188-NW) Quadrangle; Lee
Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

Discussion—This species is distinguished by its large size and its direct un-

404 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

bifurcated costae. In these respects it resembles D. atavoides but differs in its
more slender lateral profile, details of the ornamentation, and a differently pro-
portioned pedicle valve which has much less depth than that of D. atavoides.

Genus VALCOUREA Raymond, 1911

Valcourea Raymonp, Ann. Carnegie Mus., vol. 7, p. 239, pl. 35, figs. 15-19, pl. 36, fig. 1,
text fig. 12, 1911; Valcourea (part) ScHUCHERT and Cooper, Mem. Peabody Mus. Nat.
Hist., vol. 4, pt. I, p. 97, 1932.

The specimens described herein permit a reevaluation of the genus Valcourea.
The description of the genus offered by Schuchert and Cooper in 1932 includes
two groups of shells now separated under the names Campylorthis and Chaulisto-
mella. These two genera hitherto included in Valcourea generally occur in later
strata than those containing Valcourea, and as far as known the three do not
occur together.

As repeatedly pointed out, Valcowrea is a member of the Dinorthidae, retain-
ing many primitive characters, and is probably the earliest known member of
the family. External as well as internal features distinguish Valcourea from other
members of the family. A pseudodeltidium and chilidial plates are constant
features in all known species. Another feature constant in all species described
herein is the more or less prominent, narrow, carinate fold that originates on
the umbo of the pedicle valve and extends for a greater or less distance toward
the anterior margin. This fold is most pronounced in the earliest members such
as V. intracarinata and V. strophomenoides but is not very marked in an unde-
scribed species (Valcourea sp. 2) from the Lincolnshire limestone of Tennessee.
Corresponding to the fold of the pedicle valve is a more or less deep and long
sulcus extending from the umbo of the brachial valve to the middle or beyond.
When this sulcus is deep, it helps to emphasize and heighten the median ridge
inside the brachial valve.

Inside the pedicle valve perhaps the most characteristic generic feature is the
more or less strongly developed subperipheral rim which is a common feature of
convexi-concave shells. This rim may be strongly thickened or may be only poorly
developed. A negative feature of the genus is the lack of preservation of the
pallial marks. The course of these sinuses is usually well marked in many mem-
bers of the Dinorthidae, but only a few specimens of Valcourea have been seen
that show any details of them. Such a specimen is Valcourea sp. 2 (110257)
which shows the strong trunks of the vascula media originating at the anterior
ends of the diductor impressions. These bifurcate almost exactly at their point
of origin, the inner branches extending anteromedially and the outer ones extend-
ing slightly anterolaterally. Both sets of trunks are directed chiefly in an anterior
direction unlike other members of the Dinorthidae in which the bifurcated
branches extend anteromedianly and posterolaterally.

In the brachial valve the feature of generic importance is the cardinal process.
This has a short and stout shaft but a prominent myophore. Generally the
myophore is trilobed, the amount of lobation depending on the age of the speci-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 405

men. The median lobe always bears a strong carina, a feature not present in
closely related genera such as Multicostella and Campylorths.

As far as present knowledge goes, Valcourea typifies the Marmor, Ashby, and
lower part of the Porterfield stages. It appears first in the upper part of the
Upper Pogonip of Nevada, is abundant in the Crown Point formation of New
York, the Lenoir of Tennessee, the Lincolnshire and Whistle Creek formations of
Virginia. The stratigraphically highest specimens known occur in the lower part
of the Bromide of Oklahoma, the lower Eureka of Nevada, and the Long Point
series of Newfoundland. The genus is thus an excellent guide to a narrow band
of the geological column.

VALCOUREA ANGULATA (Phleger)
Plectambonites angulatus PHLEGER, Bull. S. California Acad. Sci., vol. 32, pt. 1, p. 17, pl. 1,
fig. I, 1933.
Horizon and locality.—Barrel Spring formation California: In Barrel Spring
Canyon, Inyo Mountains.

VALCOUREA AUSTRINA Cooper, new species
Plate 75, B, figures 6-27

Valcourea strophomenoides Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 41, pl. 73, figs. 1-8,
1942.

Shell fairly large for the genus; hinge forming the widest part; cardinal ex-
tremities acute, occasionally auriculate. Anterior commissure broadly sulcate.
Lateral margins faintly convex, sloping anteromedially. Anterior margin broadly
rounded. Surface multicostellate, with 17 to 19 costellae in 5 mm. at the front
margin of a valve 13 mm. long. Costellae narrowly rounded, strongly elevated.

Pedicle valve gently convex in the posterior third to half ; gently to moderately
deeply sulcate in the anterior half to two-thirds. Fold short, narrow, subcarinate,
extending to about the middle of the valve where it is lost. Anteromedian sector
depressed into a sulcus varying in depth on different individuals from barely
perceptible to moderately deep. Flanks on each side of fold slightly convex in
posterior half; flanks on each side of sulcus in anterior portion flat to gently
concave. Cardinal extremities slightly depressed toward the brachial valve. In-
terarea short, strongly apsacline. Pseudodeltidium short.

Brachial valve moderately and evenly convex in lateral profile; in anterior
profile the valve is humped up in the middle but flattens somewhat to the mar-
gins by a gentle descent. Sulcus, short, shallow, inconspicuous in most cases, be-
coming obsolete or faint in some specimens anterior to the middle. Anterior
half to third thrown into a low, broad fold corresponding to the broad pedicle
sulcate region. Flanks bounding fold and sulcus gently convex. Area between
flanks and deflected cardinal extremities gently concave.

Muscle field of pedicle valve large, subrectangular at the front ; diductor tracks
large. Subperipheral rim strong.

406 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
IOLOtYpe Wore escent 13.5 12.9 17.9 19.6 3.9
Paratype (110195a).. 14.5 14.4 20.5 23.6-++ 4.2
‘4 (116965b) .. 17.3 16.9 22.2 22.7 7.9

Types.—Holotype: 98177a ; figured paratypes: 98177b,d,e, 110195a, 116965a,
b; unfigured paratypes: 98177c,f-h, 110195b.

Horizon and locality—Whistle Creek formation in Virginia: 14 miles north-
west of Lexington; Brushy Hills, on the road to Lexington; on U. S. High-
way 60, 100 yards southeast of Whistle Creek, 2 miles northwest of Lexington,
Lexington (15’) Quadrangle.

Ellett formation in Virginia: Ellett, Lusters Gate, Blacksburg (15’) Quad-
rangle.

Discussion.—Valcourea austrina is characterized by a moderately strong
median fold on the pedicle and a shallow but well-defined sulcus in the brachial
valve, but both of these features are generally obsolete at the front of the adult
shell. This species attains a fairly large size, almost the largest at present known.
In this respect it resembles V. deckeri from the Tulip Creek formation in Okla-
homa but differs in the more pronounced development of the fold and sulcus,
the greater depth to the concave portions of the pedicle valve, and a less evenly
convex brachial valve. The pedicle muscle area of the Whistle Creek species is
squarer across the front than that of V. deckeri in which the diductor impressions
are somewhat elongated. This species resembles ’. ventrocarinata in the gen-
eral form of the valves but differs in having a less concave pedicle valve and in
having a less well developed fold and sulcus.

VALCOUREA BREVICARINATA Cooper, new species
Plate 75, A, figures 1-5

Shell of about medium size for the genus, wider than long with the hinge form-
ing the widest part. Cardinal extremities acutely alate; sides sloping medially ;
anterior margin somewhat narrowly rounded. Costellae narrowly rounded, of
unequal size, about 15 in 5 mm. at the front of a valve 12 mm. long.

Pedicle valve gently concave in lateral profile. Umbonal region marked by
a narrow but short carina that extends indistinctly to the middle of the valve
where it is lost in the general concavity. Median and lateral regions moderately
concave; cardinal extremities somewhat flattened, large specimens tending to
develop a narrowly rounded, sulcate front. Interarea short, strongly apsacline.

Brachial valve fairly strongly convex in lateral profile with the greatest con-
vexity in the median region; anterior profile broadly convex but somewhat nar-
rowly rounded in the median region. Umbonal region sulcate, the sulcus short
and narrow. Sulcus disappearing on the somewhat inflated median area and not
extending anterior to the middle. Flanks bounding sulcus slightly convex, and
slopes to cardinal extremities gentle. Anterior slope moderately steep but becom-
ing less inclined posterolaterally toward the cardinal extremities.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 407

Pedicle interior with margin thickened slightly. Muscle area small and deli-
cate with elongate diductor impressions. Pallial trunks not impressed. Brachial
interior with short and narrow median ridge and small, delicate cardinalia.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Rate: bayeleh gies Wem. dees Ue 11.8 12.3 16.4 ? 2.4
Paratype (pedicle valve 110248a)..... 12.3 ? 14.6 16.8-- ?
es (brachial valve 110248b).... ? 12.0 15.8 20.0 ? 3.0

Types.—Holotype: 110248c; figured paratypes: 110248a,b; unfigured para-
types ; 110248d,e.

Horizon and locality—Upper part of the Arline formation in Tennessee:
North side of wagon road in glade, 4 mile southeast of Friendsville; 100 yards
southwest of Negro Cemetery, 4 mile northeast of Friendsville, Concord (T.V.A.
138-SW ) Quadrangle; 1,500 feet south of the mouth of Burnett Creek, Shooks
Gap (T.V.A. 147-NE) Quadrangle.

Discussion—This species is characterized by the shortness of the median
carina and corresponding sulcus. Both these features are confined chiefly to the
umbonal region and do not extend past the middle of either valve. In this re-
spect the species differs from V’. ventrocarinata which it otherwise resembles.
It differs from V. austrina in having a more concave pedicle valve, a brachial
valve with a somewhat more inflated median region, and with more prominent
diversity of costellae in the ornamentation. V’. brevicarinata differs from V. ob-
scura, from the Lenoir formation, in having a more pronounced carina, finer
costellae, deeper pedicle valve, and more convex brachial valve.

VALCOUREA DECKERI Cooper, new species
Plate 74, A, figures I-14

Shell moderately large, wider than long with the hinge usually forming the
widest part. Cardinal extremities varying from an acute angle in the young to
nearly a right angle in old adults. Lateral margins varying from nearly straight
to strongly oblique. Anterior margin broadly rounded. Surface multicostellate,
17 or 18 costellae in a distance of 5 mm. at the front margin of the holotype.
Scattered costellae larger than those surrounding them often present.

Pedicle valve only slightly convex in the posterior one-quarter to one-third ;
gently concave in the front two-thirds to three-quarters. Fold narrow, moder-
ately strong in the umbonal region, faint but perceptible from there to the front
margin. Lateral regions slightly concave. Cardinal extremities slightly deflected
toward the brachial valve. Interarea strongly apsacline to catacline. Pseudo-
deltidium narrow, long.

Brachial valve with the maximum convexity at about the middle. Umbo
gently concave. Sulcus narrow at the umbo, widening anteriorly and reaching
the anterior margin; very shallow in the anterior third. Flanks bounding sulcus
moderately swollen. Slopes to cardinal extremities gentle.

408 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Interior: Pedicle muscle area with the diductor tracks extended anterior to
the adductor track; pallial impressions not well developed. Brachial valve with
stout cardinal process having a thick shaft and wide trilobed myophore. Central
lobe of myophore with strongly elevated carina.

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
Holotype)... bees « 88 17.5 17.5 23.3 225 5.1
Paratype (110208d).. 13.9 13.9 20.3 23.1 3.7
y (110208e).. 11.3 10.7 16.5 21.5 3.1
- (110216b).. 15.0 15.0 20.5 23.8 4.6

Types—Holotype: 110208a; figured paratypes: 110208b,c,e, I102IIb,c,
110212a,b ; unfigured paratypes : 110208d, 110211a; measured paratype: 110216b.

Horizon and locality —Tulip Creek formation in Oklahoma: Beside road 14
miles west of Nebo, SEASW3 sec. 22, T. 2 S., R. 3 E.; valley of West Spring
Creek, 3 miles east of Pooleville, Murray County.

Discussion.—This species attains a large size for the genus. In outline it
varies considerably according to its age. In general the younger forms are much
extended at the hinge, but the cardinal extremities of the older specimens are
more nearly a right angle. Some young forms occur without alate extremities,
a condition believed to be due to crowding in growth. This species resembles
another large form occurring in the Whistle Creek formation of the Appalachians,
V. austrina, but differs in possessing a flatter pedicle valve and shorter, less
strongly developed fold and sulcus.

VALCOUREA INTRACARINATA Ulrich and Cooper
Plate 73, A, figures 1-4

Valcourea ? intracarinata UtricH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 125,
pl. 21C, figs. 9-12, 1938.

When this species was originally described its assignment to Valcourea was
questioned. At that time the strong carina on the median lobe of the cardinal
process was not known to be a distinctive feature of the genus. This carina, as
well shown herein, is a generic character in Marmor and later specimens, but
absent from a group of post-Marmor shells formerly placed in Valcourea but
now referred to Campylorthis.

This species is especially distinguished by its small size, great width, strong
median ridge inside the brachial valve, and the deep median sulcus. It is per-
haps the earliest known species of the genus.

Types.—Holotype: 92852f; paratypes: 92852a-e,g-i; additional specimens:
110226.

Horizon and locality—Upper part of Upper Pogonip group (Valcourea zone)
in Nevada: In Ikes Canyon on the east side of the Toquima Range, Roberts
Mountains (1°) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 409

VALCOUREA OBSCURA Cooper, new species
Plate 76, A, figures 1-10

Shell of about medium size for the genus, wider than long, with the hinge
forming the widest part. Cardinal extremities generally acute to alate. Lateral
margins gently convex; anterior margin broadly rounded. Surface marked by
subangular costellae separated by interspaces wider than the costellae. About
13 costellae in 5 mm. at the front margin of a shell 8 mm. long.

Pedicle valve gently concave with the most concave part slightly anterior to
the middle. Umbo carinate; carina short and narrow, indistinctly extending to
the anterior margin as a slight elevated area. Posterolateral areas flattened. In-
terarea strongly apsacline.

Brachial valve strongly convex in lateral profile but broadly convex in an-
terior profile. Umbo marked by a narrow and shallow sulcus that is extended
anterior to the front margin where it has widened considerably but occupies only
about 2 mm. Flanks bounding sulcus somewhat inflated. Anterior slope mod-
erately steep.

Pedicle interior with stout dental plates, the usual muscle field for the genus,
but poorly defined pallial marks. Brachial interior with stout median ridge
extending to about the middle. Brachiophores small but stout.

Measurements in mm.—
Hinge

Length Width width Thickness
FHolotypel Mek Ii ese 10.8 14.4 16.3-+ 3.0
Paratype M(rla254d re cnt. oe 8.3 13.0 14.3 2.5
i (GUO 2S) eae kis: 8&9 15.5 14.3-++ ans
# (TITOZ5AA) sakes Stele 0.4 14.9 16.3-+ ?

Types.—Holotype: 110254e; figured paratypes: 110254d, 116966; unfigured
paratypes: I110254a-c.

Horizon and locality Lenoir formation in Tennessee: 2 miles south of Phila-
delphia ; small quarry between the Southern Railroad tracks and U. S. High-
way I1, 14 miles southwest of Philadelphia, Philadelphia (T.V.A. 131-NW)
Quadrangle.

Discussion.—This species is suggestive of V. transversa but differs in being
less wide and in possessing stronger costellae. Its smaller size and less deeply
concave pedicle valves with poorly developed carina distinguish the species from
V.ventrocarinata, The smaller size and stronger costellae distinguish this species
from V. austrina, and the latter character serves to differentiate it from V. semi-
carinata and V. brevicarinata.

VALCOUREA PLANA Cooper, new species
Plate 72, C, figures 14-21; plate 73, C, figures 15-22
Outline semielliptical with the hinge forming the widest part, sides sloping
medially and the anterior margin somewhat narrowly rounded. Costellae nar-

rowly rounded and separated by interspaces wider than the costellae, about 15
or 16 in the space of 5 mm. at the front margin of the holotype.

410 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve nearly plane or gently concave in lateral profile. Fold low and
narrowly rounded, originating on the umbo and extending anteriorly for about
two-thirds to three-fourths the length where it disappears in a short and shallow
sulcus that depresses the front of the valve. Lateral areas nearly flat. Interarea
short and apsacline.

Brachial valve evenly and moderately convex in lateral profile; slightly more
convex but broader in anterior profile. Sulcus not deeply impressed and extend-
ing to about the middle or anterior third. Entire valve gently inflated and with
long moderately steep slopes to the anterior and lateral margins.

Pedicle interior with the usual muscle area having elongate diductor impres-
sions but a fairly wide and large adductor track. Pallial marks occasionally
deeply impressed. Median ridges inside brachial valve strong, fairly elevated,
and extending slightly anterior to the middle.

Measurements in mm.—
Hinge

Length Width width Thickness
TIQIOEU DEY sis dict c Powis aia a! ae xieioin, wteimretelereeets 12.4 19.7 ? 2.9
Paratype (pedicle valve 116968b)....... 9.0 15.5 20.6 ?
" (brachial valve 116968a)...... 10.0 17.9 22.4 ty

Types.—Holotype: 116967; figured paratypes: 110265a,c; 116968a,b,
117994a; unfigured paratypes: 110265b,d-f, 116969, 117994b-g.

Horizon and locality—Yellow limestone overlying 25-foot sandstone at base
of Eureka group, Roberts Mountains (1°) Quadrangle in Nevada: 2 to 3 miles
north of Martin Ranch; on crest of Antelope Range, 3 miles south of Nine Mile
Canyon; saddle just north of hill 8167, Martin Ridge, Monitor Range.

Discussion.—No other species is quite like this one in having such a flat pedicle
valve. This character is approximated by V. austrina, but that is a larger species
than the Nevada one and differently ornamented. Valcourea plana occurs with
abundant specimens of Sowerbyites, which help to fix its age as about that of
the Lincolnshire formation of Viriginia and Tennessee and the basal part of the
Bromide in Oklahoma.

VALCOUREA SEMICARINATA Cooper, new species
Plate 70, A, figures 1-10

Valcourea strophomenoides Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 41, pl. 73, figs. 9, 10,
1942,

Shell of about medium size for the genus, wider than long with the hinge
usually forming the widest part ; cardinal extremities varying from alate to nearly
a right angle. Lateral margins oblique, anterior margin broadly rounded. Sur-
face multicostellate, costellae about 3 or 4 to the millimeter at the front margin.

Pedicle valve gently convex in lateral profile in the posterior half but gently
to moderately convex in the anterior half. Umbo carinate, the carina low and
extending to about the center where it is lost in a broad shallow depression or
continued to the front margin as a broader but very faint undulation. Areas
bounding carina gently concave but the posterolateral areas flattened and bent

PART \I CHAZYAN AND RELATED BRACHIOPODS—COOPER 4II

slightly toward the brachial valve. Beak slightly protruding beyond posterior
margin. Interarea strongly apsacline; pseudodeltidium narrowly convex and
short. Muscle area with the usual form for the genus, about as long as wide;
the diductor impressions often bounded on both sides and at the front by low
thickenings of callus. Ovarian impressions small.

Brachial valve flattened or gently concave in lateral profile in the posterior
third but gently convex in the anterior two-thirds; in anterior profile broadly
convex with the sides descending in long gentle slopes and the median region
slightly sulcate. Umbo sulcate, the sulcus extending to about the middle as a
narrow and fairly deep depression, but anterior to the middle it may be lost nearly
completely or continued as a shallow but wider depression nearly to the front
margin, although rarely attaining that end. Anterolateral areas bounding the
sulcate region gently swollen; posterolateral slopes gentle with the region just
anterior to the cardinal extremities slightly concave. Median elevation of the
brachial interior extending to the middle but not strongly elevated. Cardinal
process small, with a strong median carina. Brachial processes short.

Measurements in mm.—

Hinge
Length Width width Thickness
FTOMOE VE arate akete crelal nie eave oy steers |s) 3/8 shes 9.3 13.0 15.5 2.5
Paratype (pedicle valve 110228e)...... 10.6 14.0 17.5 ?
& (uOz2Ga iinet oo ess FES 12.6 15.3 2.2

Types.—Holotype: 110228d; figured paratypes: 98179, 110228e,g; unfigured
paratypes: 110228a-c,f.

Horizon and locality —Upper part of the Arline formation in Virginia: Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion—This species is most similar to V. brevicarinata but differs in
having finer costellae, a different outline, and stronger fold. Furthermore,
V.. semicarinata is a flatter shell and has the posterior of the brachial valve con-
cave or somewhat flattened.

VALCOUREA STROPHOMENOIDES (Raymond)
Plate 74, B, figures 15-25

Plaesiomys strophomenoides RayMonp, Amer, Journ. Sci., ser. 4, vol. 20, p. 370, 1905.
Valcourea strophomenoides RAyMonD, Ann. Carnegie Mus., vol. 7, No. 2, p. 240, pl. 35,
figs. 15, 17, 19 (not figs. 16, 18) ; pl. 36, fig. 1, text fig. 12, rort.

The young of Valcourea strophomenoides generally possess a wide hinge and
acute cardinal extremities. As the shell increases in age and additions are made
to the margins, these tend to elongate the shell and give it a more quadrate form.
The adult is thus one in which the width slightly exceeds the length and the
cardinal extremities are approximately a right angle or are slightly obtuse.

The umbo of the pedicle valve is strongly carinate, but the carina is continued
as a fold for about one-half to three-quarters the length of the valve. As a
rule the fold is lost in the front quarter which often is bent noticeably in an an-
teropedicad direction. The sulcus of the brachial valve is deepest at the umbo

412 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

where the fold of the opposite valve is the strongest, and becomes shallower at
the middle and front. At the front margin of an adult specimen the sulcus is
exceedingly faint or absent.

The surface of this species is finely multicostellate, but the costellae are of
unequal size and appear in at least 3 generations by intercalation.

Measurements in mm.—Holotype, length 12.0, brachial length 10.8, width 12.9,
hinge width 11.8.

Types.—Holotype: Carnegie Mus. 5450; figured paratypes: Carnegie Mus.
5466, 5467, 5492.

Horizon and locality——Crown Point formation in New York: Chazy, Rouses
Point (15’) Quadrangle; Valcour Island and Crown Point, Plattsburg (15’)
Quadrangle. Same formation in Vermont: At Fort Cassin, Port Henry (15)
Quadrangle.

Discussion.—The type specimens show this species to be a small form about
one-third wider than long and with fine costellae covered by fine elevated fila.
The brachial interior figured by Raymond (pl. 35, figs. 16, 18) and said to be-
long to this species has the characters of Multicostella platys and is a larger
and more coarsely costellate shell.

Valcourea strophomenoides is characterized by its small size, somewhat rec-
tangular outline, small muscle area, and shallow brachial valve. It differs from
V. obscura in having less angular cardinal extremities, finer costellae, and a
shorter, less prominent carina on the pedicle valve.

VALCOUREA TENUIS Cooper, new species
Plate 76, D, figures 18-29

Shell of about medium size for the genus, wider than long, transverse in young
stages; hinge forming the widest part; sides nearly straight, oblique; anterior
margin broadly rounded. Anterior commissure rectimarginate. Surface costel-
late, costellae separated by spaces about equal in width to the width of a costella;
about 20 costellae in 5 mm. at the front margin.

Pedicle valve gently concave in lateral profile, most concave in the median
region ; fold low, originating at the beak and extending distinctly to a point near
the middle; anterior to that point fold low and indistinct to the anterior margin.
Flanks bounding fold gently concave ; posterolateral extremities flattened. Inter-
area short, apsacline; pseudodeltidium short. Interior with muscle field not
reaching the middle, subperipheral rim strong.

Brachial valve gently convex in lateral profile; broadly and gently convex in
anterior profile; sulcus deep, narrow, deeply entrenched in the posterior two-
thirds, indistinctly defined in the anterior third ; flanks bounding sulcus narrowly
but gently folded; posterolateral areas depressed, slopes short and gentle. In-
terior with median ridge strongly defined nearly to the front margin; brachio-
phores short, supported by callus; cardinal process with a long and stout shaft.

PART 1 CHAZYAN AND RELATED BRACHIOPODS—COOPER 413

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
1s 2S 9h cayerensteins el omnia grad tai 6.9 6.9 10.8 12.3 1:2
Paratype “Cr r6o70c)o. . LP Basle 9.0 9.6 13.1 15.9 1.1
K (pedicle valve 116970j) 7.7 ? 12.6 15.4 ?

Types.—Holotype: 116970e; figured paratypes: 116970a,b,d,f,g,1,j ; unfigured
paratypes: 116970c,h.

Horizon and locality —Tulip Creek formation (152 feet above the basal sand)
in Oklahoma: On the first creek east of U. S. Highway 77, SE{NENE sec. 25,
T.2S., R.1E., Carter County ; West Spring Creek, 24 miles east of Pooleville,
Murray County.

Discussion—This species occurs in abundance in a few places. Generally
young transverse specimens are far more abundant than adults. In the young
form the species suggests V’. transversa, but it is generally smaller and less
convex.

VALCOUREA TRANSVERSA Cooper, new species

Plate 72, D, figures 22-31; plate 76, B, figures 11-14

Shell of about medium size for the genus; wider than long with the length
ranging from one-half to two-thirds the width at the hinge; hinge wide, forming
the widest part, often mucronate and with acute extremities ; sides oblique, nearly
straight; anterior margin broadly curved; anterior commissure rectimarginate ;
surface marked by costellae of unequal size, the large ones scattered among the
finer ones, 3 or 4 in I mm. at the front margin; costellae crossed by strong,
elevated concentric fila about 8 to the millimeter.

Pedicle valve evenly and fairly deeply concave, with the greatest depth in the
median region; umbo sharply folded; fold low, distinct to middle but obscure
from there to anterior margin; posterolateral extremities just anterior to pos-
terior margin slightly sulcate ; posterior margin forming a thickened and elevated
rib; interarea long, strongly apsacline; pseudodeltidium long and strongly
elevated.

Brachial valve unevenly convex in lateral profile, the posterior third flattened
to slightly concave, median third strongly convex, anterior third gently convex ;
anterior profile broadly convex with the median region narrowly sulcate ; umbo
flat to gently concave, fairly deeply and narrowly sulcate; sulcus extending for
two-thirds the length but disappearing on the anterior slope; median region in-
flated ; flanks somewhat depressed and with gentle slopes.

Pedicle interior with deeply impressed muscle area with thickened margins,
extending nearly to middle; brachial interior with stout brachiophores supported
by callus deposit ; cardinal process with stout shaft and high-crested myophore.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Higigtyperceak ees.) Saas 9.8 10.2 15.2 19.0 2.5
Paratype (116072b) |. 95 2s ashes 11.4 11.4 17.7 18.5 3.5

“fi (BIG972a)) siete eres 11.9 11.9 17.5 19.6 3.6

414 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 116971 ; figured paratypes: 116972b,d, 110277b; unfigured
paratypes: 110277a,c,d, 116972a,c.

Horizon and locality.—Lower Bromide (Mountain Lake member—small Val-
courea bed) in Oklahoma: On Oklahoma Highway 99, 3 miles south of Fitts-
town, Pontotoc County; top of zone 7, Rock Crossing of Hickory Creek, center
sec. 35, 1.5 9., R. 1 E,,.Carter County; U. S. Highway.77, NE4 sec. 25,,T..2.5.,
R. 1 E., Carter County; Falls Creek, SWiNW4SW3 sec 33, T. 1 S., R. 2 E,,
Murray County ; “reef” beds on west side Oklahoma Highway 18, 1.8 miles south
of Sulphur, Murray County; 49 to 66 feet above the Bromide sandstone on
Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray County.

Discussion.—This species is characterized by its transverse form and the fine
costellate ornamentation. It is not like any of the Valcoureas of the Appalachians.
It differs from V. deckeri in its generally smaller size and wider outline.

VALCOUREA VENTRO-CARINATA (Butts)
Plate 71, C, figures 10-14; plate 73, B, figures 5-14

Strophomena ventro-carinata Butts, Alabama Geol. Surv., Special Rep. 14, pl. 16, figs. 16, 17,
1926.—ScHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 97, 1932.

Shell fairly large for the genus, subquadrate to subrectangular with the width
slightly greater than the length; hinge forming the widest part; sides gently
convex, oblique; anterior margin narrowly rounded; anterior commissure recti-
marginate ; surface costellate, costellae closely crowded, about 13 in 5 mm. at the
anterior margin. Costellae crossed by closely crowded, elevated concentric fila,
about 12 to the millimeter.

Pedicle valve fairly deeply concave with the most concave part in the anterior
third; umbo prominently and sharply carinate; carina extended to the middle
as a strong narrow fold, low and indistinct from the middle to the front margin.
Areas bounding carina gently concave ; interarea strongly apsacline.

Brachial valve strongly convex in lateral profile with the greatest convexity at
about the middle; anterior profile fairly strongly convex but with the middle
narrowly sulcate. Median region inflated; umbo somewhat flattened, sulcate ;
sulcus narrow and deep in the posterior half, shallower anteriorly to the front
margin but distinctly visible; flanks bounding sulcus inflated ; posterolateral and
lateral slopes steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (117992a)........ 13.1 12.7 15.8 16.2 35
5 CLIOZAG) > srestese orb 12.4 11.9 16.9 17.6 ? 3.5

Types.—Lectotype: 71498a; figured paratype: 71498b; figured hypotypes:
110246, 1179922.

Horizon and locality.—Little Oak formation in Alabama: 4 mile north of Pel-
ham on U. S. Highway 31, Bessemer Iron District (15’) Quadrangle; 4 mile
south of Newala, Montevallo (15’) Quadrangle; Ragland Cement Company

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 415

Quarry, 3 miles south of Ragland, St. Clair County; junction of Cahaba Valley
road with Bailey Gap road, SW4SW3 sec. 13, T. 19 S., R. 2 W., 13 miles north-
east of Newhope Church, Vandiver (15’) Quadrangle.

Discussion ——This species is characterized by its subquadrate form, crowded
costellae, and the strength of the fold and sulcus. It is suggestive of V. austrina
from which it differs in its more concave pedicle valve, stronger pedicle fold,
and much deeper sulcus.

This species also resembles V’. brevicarinata which occurs at about the Little
Oak equivalent in Tennessee (Arline formation) but differs in its stronger fold
and sulcus and the more oblique lateral margins. It is also similar to V. semi-
carinata but differs in its stronger costellation, stronger fold and sulcus, and
more robust form.

VALCOUREA sp.

As usual with any large collection a number of specimens cannot be placed in
hitherto described species or in any of the new ones figured here. All the speci-
mens are fairly large forms mostly poorly preserved.

Valcourea sp. 1 (pl. 73, E, figs. 26, 27): This is a very poorly preserved
specimen (110203a) with a length of about 20 mm.; preserving only a trace of
the usual carinate fold and with a strong sulcus at the front of the pedicle valve
producing a nasute anterior. The brachial valve is strongly convex and has a
narrowly pinched-up fold at the front. The specimen measures 26 mm. in width
but is not complete on either side and must have been much wider. A smaller
specimen (110203b) in the same lot measures: 16 mm. in length by 23.3 mm.
The specimens were taken from the Lincolnshire formation in the Marcem
Quarry, 2 miles west of Gate City, Gate City (T.V.A. 188-NE) Quadrangle, Vir-
ginia. Figured specimen: 110203a.

Valcourea sp. 2 (pl. 73, D, figs. 23-25): Two pedicle valves, 110204 and
110257, of an unusually large and thick-shelled species, suggestive of Campy-
lorthis, represent an undescribed species. However, a trace of a pseudodeltidium
is preserved and a thickened subperipheral rim is present, features that link the
specimens to Valcourea. The other and most striking feature of these specimens
is the large size of the muscle area which in specimen 110257 extends anteriorly
from the beak for two-thirds the length and occupies nearly a fourth of the inner
area. Furthermore, the thickened, dichotomous proximal ends of the pallial
trunks are well preserved. Specimen 110204 measures: Length 15.6 mm., width
20 mm., hinge width 26 mm. The specimens were taken from the Lincolnshire
formation at Marble Bluff, 8 miles west-northwest of Loudon, Loudon (30’)
Quadrangle, Tennessee. Specimens of Multicostella from this locality are also
very thick shelled. Figured specimen: 110257.

Valcourea sp. 3: This is represented by a lot of three specimens (110256) of
a finely costellate species having a well-marked carinate pedicle fold and a nar-
row, deep brachial sulcus. The specimens suggest V. austrina but are more finely
ornamented. They also have some resemblance to V. deckeri but are too poorly

416 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

preserved to make a good comparison possible. Cherty marble in the lower 50
feet of the Red Knobs formation, 3 miles southeast of Knoxville, Tenn.

Valcourea sp. 4: A single poorly preserved specimen (110202) measuring
18 mm. in length and 23 mm. wide, with fine costellae, strongly convex brachial
valve having a sulcus extending nearly to the anterior margin, represents still
another species. Costellae number 18 or Ig in 5 mm. at the front margin. The
specimen is suggestive of . austrina but is more convex and more finely orna-
mented. Arline formation, 1 mile southeast of Fowlers Mill, 10 miles southeast
of Loudon, Loudon (30’) Quadrangle, Tennessee.

Valcourea sp. 5: Another large species (116973a,b) similar to the preceding
occurs in the Mountain Hill conglomerate of the Quebec City formation. It is
19.4 mm. long and 24.6 mm. wide. The maximum concavity is in the median
region, but the valve is not deeply concave. The fold extends from beak to an-
terior margin. This is one of the largest Valcoureas yet seen but, of all those
that have been described, is most suggestive of the Whistle Creek and Lincoln-
shire specimens.

Horizon and locality—Quebec City formation, 400 to 500 feet south of Morin
Building, Mountain Hill, Quebec.

Genus MULTICOSTELLA Schuchert and Cooper, 1931

Multicostella ScHUCHERT and Cooper, Amer. Journ. Sci., vol. 22, p. 244, 1931; Mem. Peabody
Mus. Nat. Hist., vol. 4, pt. 1, p. 98, 1932.

MULTICOSTELLA BURSA (Raymond)
Plate 64, C, figures 10-16
Hebertella bursa RayMonp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 294,
pl. 1, fig. 7, 1928.
Multicostella whitesburgensis Butts, Virginia Geol. Surv. Bull. 52, p. 67, pl. 80, figs. 14-17,
1942.

Shell of about the usual size or large for the genus, slightly wider than long
with the greatest width at about the middle. Hinge narrower than the greatest
shell width or about equal to the midwidth. Cardinal extremities acutely angu-
lar to subalate. Lateral margins generally concave just anterior to the cardinal
angie but broadly rounded anterolaterally; anterior margin broadly rounded.
Anterior commissure rectimarginate to slightly uniplicate. Valves nearly equal
in depth. Surface multicostellate ; valves marked by 70 to about 84 costellae that
appear in 3 generations by implantation.

Pedicle valve swollen in the midregion with moderately steep posterolateral and
umbonal slopes but fairly gentle anterior slope. Umbonal region narrowly swol-
len, with beak narrow and sharply produced posteriorly. Swollen umbonal re-
gion continued anteriorly as an indistinct fold to about the middle. Anterior
quarter to half bent gently in the direction of the brachial valve. Lateral profile
with the greatest depth in the posterior half; the anterior profile forming a broad
arch, Interarea of moderate length, strongly apsacline.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 417

Brachial valve having the greatest convexity in lateral profile somewhat an-
terior to the middle, forming a low arch somewhat flattened at the middle in
anterior profile. Umbo concave, with the concavity produced anteriorly as a
very shallow and narrow sulcus to a point a short distance anterior to the middle.
Median, anteromedian, and anterolateral areas moderately swollen with moder-
ately steep slopes to the margins. Posterolateral slopes gentle. Interarea nearly
as long as the pedicle one, gently anacline.

Interior: Pedicle muscle area about as long as wide and in length equal to
about a third the length of the valve. Adductor track wide, slightly elevated an-
teriorly ; diductor impressions long and narrow. Pallial trunks not strongly im-
pressed. Median ridge of brachial valve low and short, equal in length to about
one-third the length of the valve. Cardinal process short and stout; myophore
not greatly thickened.

Measurements in mm.—

Hinge Thickness
Length Width width

Hypotype (pedicle valve 110371d)...... 22.4 26.3 23.2 4.2
‘ Cmio37ie) wisiiiuss Jute. vlc 23.7 26.7 22.8 5.4
Ԥ (brachial valve 110371a).... 24.3 27.3 23:2 5.5

Types.—Holotype: M.C.Z. 8597; figured hypotypes: 110371a,b,d,e, 110372a,
b, 116984h; unfigured hypotypes: 11037Ic, 116984a-g.

Horizon and locality—Chatham Hill formation in Virginia: Grayson Farm,
4 miles southwest of Bland, Bland County ; 1.2 miles S. 31° E. of Sharon Springs,
Burkes Garden (15’) Quadrangle.

Botetourt formation in Virginia: Near Dunkard Church, 7 miles west of
Natural Bridge, Natural Bridge (15’) Quadrangle; junction Virginia Highways
311 and 114, $ mile southwest of Catawba, Salem (15’) Quadrangle; about 1
mile northwest of Lexington, Lexington (15’) Quadrangle; 14 miles southeast
of Harrisonburg, Harrisonburg (15’) Quadrangle.

Whitesburg formation in Tennessee: In the railroad cut at Summit Hill
school, 1 mile southwest of Otes, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Discussion.—This species is known from a few specimens only: The holo-
type, which is preserved in the Museum of Comparative Zoology, Harvard; a
few fine valves etched out of black limestone; and a few exfoliated specimens
preserved in black limestone. The species is characterized by its strongly bicon-
vex form, a hinge narrower than the greatest shell width, and fairly strong
costellae. This species most closely resembles M. convexa but differs in the nar-
rower hinge, somewhat squarer form, and lesser development of the sulcus of
the brachial valve. M. bursa differs from M. plicata in the lesser number of cos-
tellae and possession of a smaller muscle area in the pedicle valve. Multicostella
whitesburgensis Butts occurs at about the same horizon as M. bursa and has simi-
lar exterior characters to that species. It is therefore placed as a synonym of
Raymond’s species.

418 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 127

MULTICOSTELLA CONVEXA Cooper, new species
Plate 60, A, figures 1-19; plate 61, A, figures 1-6

Shell large, semielliptical in outline, a little wider than long, with the hinge
slightly greater than the width at the middle. Cardinal extremities approximately
a right angle, auriculate in the young. Lateral margins nearly straight in the
adult ; anterior margin broadly rounded. Anterior commissure faintly uniplicate
in the adult. Surface multicostellate, costellae low, rounded, with interspaces
equal in width to the width of the costellae; 4 to 5 costellae occupy a space of
5 mm. at the front of a large specimen.

Pedicle valve unevenly convex in lateral profile, the umbo moderately convex,
the midregion flattened and the anterior third subgeniculate. Anterior profile
broadly and gently convex. Beak and umbo narrowly swollen, but this folding
extends only for a short distance. Umbonal slopes to the cardinal extremities
gentle. Lateral, anterior, and midregions slightly swollen. Interarea slightly
longer than the brachial interarea, slightly apsacline; beak pointed, incurved.

Brachial valve unevenly convex in lateral profile, the greatest convexity located
in the midregion. Anterior profile broadly and moderately strongly arched. Sul-
cus shallow, narrow, poorly defined, located in the posterior half. Anteromedial
and anterolateral portions moderately swollen. Slopes to cardinal extremities
gentle, long. Cardinal extremities slightly deflected in direction of brachial valve.
Interarea long, anacline.

Pedicle interior with the muscle field confined to the posterior third; dental
plates nearly obsolete; ovarian impressions small. Brachial valve having cardi-
nal process with a long, slender shaft, narrow myophore; lateral or secondary
processes strongly developed in some specimens. Median ridge short.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
ETOLGtY PO etevictas« cis sneer aus 24.4 23.7 30.8 B13 9.9
Paratype; (110380a)) sas laers ers 22.5 21.9 27.0 28.0 9.5
¥ CTIGOREE Ls cect © 23.0 22.0 28.3 28.5 10.4

Types.—Holotype: 110389a; figured paratypes: 110380a,b, 110385b-d,
110386a,b, 116986a,b; unfigured paratypes: 110380c, 110385a,e, 110386c,
110389b-j.

Horizon and locality—Lower Bromide formation (Mountain Lake member)
in Oklahoma: At Rock Crossing of Hickory Creek, about center sec. 35, T. 5 S.,
R. 1 E.; Mountain Lake, east half sec. 22, T. 2 S., R. 1 W.; Carter County.
Dam in sec. 17, T. 2 S., R. 1 W, Murray County.

MULTICOSTELLA FASCICULATA (Butts)
Plate 56, C, figures 26-28; plate 71, D, figures 15-20
Dalmanella fasiculata (sic) Butts, Alabama Geol. Surv. Special Rep. 14, p. 116, pl. 26,
figs. 3, 4, 1926.

Nine specimens additional to the type permit a fuller description of the species
and correct generic assignment.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 419

Shell of about median size for the genus; wider than long with the hinge nar-
rower than the midwidth; sides rounded; anterior margin broadly rounded ; an-
terior commissure rectimarginate ; valves subequally convex; surface unequally
costellate, the strong costellae scattered among the finer ones; about 3 costellae
to the millimeter at the anterior margin.

Pedicle valve unevenly convex in lateral profile, the posterior half gently con-
vex but the anterior half flattened; anterior profile with the median region nar-
rowly folded with long, gentle and flat slopes to the margins; umbo narrowly
swollen, the swelling continued anteriorly for about half the length as a low
fold; flanks bounding fold depressed slightly and with gentle slopes to the ex-
tremities. Interarea moderately long, apsacline.

Brachial valve with a gently convex lateral profile; anterior profile broadly
but gently convex and with the median region narrowly depressed ; umbo sulcate,
sulcus narrow and shallow, extending to about the middle where it becomes
shallower and wider, nearly to disappear at the front margin; flanks bounding the
sulcus somewhat swollen; posterolateral slopes long and gentle; interarea short
and gently anacline.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotyperid as. est nihews omonrs } 9.7 9.0 11.6 11.6 4.2
Hypotype (116987) .......... 13.5-+ 13.0 17.2 iy 5.9

Types.—Holotype: 71493; figured hypotype: 116987.

Horizon and locality.—Little Oak formation in Alabama: On U. S. Highway
31, 4 mile north of Pelham, 660 feet east of the intersection of main Cahaba Val-
ley road with Helena road, Bessemer Iron District (15’) Quadrangle; junction
of Bailey Gap and Cahaba Valley roads, 13 miles northeast of Newhope Church,
SWiSW3 sec. 13, T. 19 S., R. 2 W., Vandiver (15’) Quadrangle.

Discussion.—In size and form this species suggests M. robusta, but it is much
more strongly costellate and the costellae are strongly fasciculate. It is possible
that the specimens of this species so far available are in reality only young ones.

MULTICOSTELLA GERONTICA Cooper, new species
Plate 62, C, figures 15-20

Shell large, subquadrate in outline with the width greater than the length;
cardinal extremities acutely angular, subauriculate. Valves subequal in depth and
convexity, the brachial valve having slightly more depth than the pedicle valve.
Lateral margins concave just anterior to the cardinal extremities or obliquely
straight ; anterior margin broadly rounded. Anterior commissure rectimarginate.
Surface multicostellate, with 7 to 10 costellae in 5 mm. at the front of an adult.

Pedicle valve with the most convex part in the umbonal region, flattened an-
teriorly. Fold obsolete anterior to the posterior third. Anterior half and flanks
very gently convex ; slopes to cardinal extremities very gentle. Beak fairly large,
protruding beyond the posterior margin. Interarea moderately long, curved,
apsacline.

420 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve with a barely visible sulcus in the posterior half; front half
gently convex; flanks gently convex; slopes to cardinal extremities short but
gentle. In lateral profile the valve is gently convex with the maximum convexity
near the middle.

Interior: Pallial marks of both valves well developed as elevated ridges. Cardi-
nal process elongate, large.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
TI OIOLGDE aan «ides cae = de baae hess, 458 21.8 ? 16.6 28.6 4.1
Paratype: (TTOZO2E) eiac)s' ess cns ce sane 21.7 23.3 27.4 ? 4.9
© (pedicle valve 110392g)... 23.3 ? 20.3 29.0 ?
4 (brachial valve 110392c).. ? 21.6 26.7 23.4 3.7

Types.—Holotype: 110392f; figured paratypes: 110392a,c,g; unfigured para-
types: 110392b,d,e,h.

Horizon and locality.—Lincolnshire formation in Tennessee: Marble Bluff,
8 miles west-northwest of Loudon, Loudon (30’) Quadrangle.

Discussion.—This species is characterized by its wide hinge and fine costellae
together with the large and elongate muscle area of the pedicle valve and strong
pallial marks of both valves. In form the species suggests M. bursa but is more
strongly costellate. It does not possess the strong pedicle carination and deep
sulcus of M. plicata.

MULTICOSTELLA PARALLELA Cooper, new species
Plate 61, C, figures 11-15

Shell of about medium size for the genus, wider than long but subquadrate
in appearance; cardinal extremities approximately a right angle; sides nearly
straight; anterior margin somewhat narrowly rounded; anterior commissure
rectimarginate ; lateral commissure slightly deflected toward the brachial valve ;
surface multicostellate, costellae numbering Io in 5 mm. at the anterior margin.

Pedicle valve very gently convex in lateral and anterior profile; umbo nar-
rowly swollen into a low and narrow fold that extends to the middle distinctly
but is barely perceptible anterior to that point; flanks flattened and gently slop-
ing to the margins. Interarea long, approximately catacline.

Brachial valve fairly strongly convex in lateral profile, broadly but moder-
ately convex in anterior profile; interarea approximately orthocline, moderately
long ; umbo swollen; sulcus small and poorly defined; flanks and median half
somewhat swollen and having about the same convexity; posterolateral slopes
short and moderately steep; posterolateral extremities fairly strongly deflected.

Measurements in mm.—Holotype, length 22.7, brachial length 23.8, width
26.0, hinge width 24.2, thickness 8.7.

Types.—Holotype: 116989b; unfigured paratype: 11698ga.

Horizon and locality—yYellow limestone on 25-foot sandstone at base of
Eureka group in Nevada: Ridge east of Martin Ranch, Roberts Mountains (1°)
Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 421

Discussion.—This species is characterized by its parallel sides, the low con-
vexity of the pedicle valve, and the fairly strong convexity of the opposite valve.
In these respects it differs from all other described species of Multicostella.

MULTICOSTELLA PLANOSULCATA Cooper, new species
Plate 62, A, figures 1-5

Shell large for the genus, wider than long, subrectangular in outline; hinge
slightly wider than the midwidth; cardinal extremities slightly acute; sides
straight, slightly oblique; front margin broadly rounded; anterior commissure
gently and broadly uniplicate; surface multicostellate, costellae approximately
equal in width to the striae ; 8 costellae in 5 mm. at the front margin.

Pedicle valve unevenly convex in lateral profile, the posterior half moderately
convex, the anterior half flattened. Anterior profile broadly and gently convex.
Umbo somewhat swollen, not narrowly plicated as in many species of the genus ;
fold indistinct on the posterior half, obsolete in the anterior half; front flattened
and depressed ; flanks flattened to gently swollen; posterolateral region depressed
and deflected toward the brachial valve; posterolateral slopes long and gentle.
Interarea short, curved, apsacline. Interior with short and narrow muscle field.

Brachial valve gently but somewhat unevenly convex, the greatest convexity
at about the middle, the anterior somewhat flattened; anterior profile broadly
and gently convex ; umbo sulcate, sulcus short and narrow, disappearing at about
the middie; median region gently swollen; flanks level with median region and
sloping gently to the lateral and posterolateral areas.

Measurements in mm.—Holotype, length 22.6, brachial length 22.4, width
27.6, hinge width 28.0, thickness 8.6.

Types.—Holotype: 110423a; figured paratype: 110412a; unfigured paratypes:
I10412b,c, 104423b-1.

Horizon and locality —Arline formation in Tennessee: 1 mile east-northeast of
Friendsville, Louisville (T.V.A. 138-SE) Quadrangle; north side of wagon road
in glade, + mile southeast of Friendsville, Concord (T.V.A. 138-SW) Quad-
rangle.

Discussion.—This species is suggestive of M. plicata but differs in not having
the strong median fold of the pedicle valve, the deep sulcus of the brachial valve.
It is reminiscent of M. quadrata in size but is more strongly costellate, differently
shaped, and somewhat less convex. Furthermore, the muscle field of M. quadrata
is proportionately larger than that of the Friendsville species.

MULTICOSTELLA PLATYS (Billings)
Plate 68, A, figures 1-4

Orthis platys Brtt1ncs, Canadian Nat. Geol., vol. 4, p. 438, fig. 15, 1859; Geol. Canada, p. 129,
fig. 54, 1863.—HALL and CLarKE, Pal. New York, vol. 8, pt. 1, p. 218, 1892.—LEsLEy,
Geol. Surv. Pennsylvania, Rep. P. 4, p. 530, 1889.—WINCHELL and ScHUCHERT, Geol.
Minnesota, vol. 3, p. 424, 1893.

Dinorthis platys (Billings) ScHucHERrT, U.S. Geol. Surv. Bull. 87, p. 216, 1897.

422 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Plaesiomys platys (Billings) RayMonp, Ann. Carnegie Mus., vol. 7, p. 238, pl. 35, figs. 13-14,
IQIl.

Multicostella platys (Billings) ScHucHERT and Cooper, Mem. Peabody Mus. Nat. Hist.,
vol. 4, pt. 1, p. 98, 1932.

Like all species of Multicostella this one is also very variable in size and cer-
tain of the details of the surface. The type specimen (G.S.C. 1034) which is pre-
served in the Geological Survey of Canada collection is a fairly large specimen
but is poorly preserved. Much of the exterior has been stripped from the shell,
making it impossible to determine the details of the costellae exactly. The con-
vexity of both valves is low and at the front of the pedicle valve the specimen is
depressed to form a broad and shallow sulcus. The sulcus of the brachial valve is
shallow and narrow and extends about to the middle of the valve. At the front of
the brachial valve a low swelling corresponds to the sulcus of the pedicle valve.
Some specimens show a clearly defined sulcus in the brachial valve extending
from the beak to the anterior margin. Ten costellae may be counted in a distance
of 5 mm. at the front margin of the holotype. Inasmuch as this specimen is much
exfoliated, it is possible that the finest costellae of the latest generation are lost
and cannot be counted. The holotype is 18.5 mm. long, 21 mm. wide, and 5.5 mm.
thick. Specimens preserving the exterior show the costellae to be narrow, ele-
vated, and bundled with ones of various sizes in several generations.

Types.—Holotype: G.S.C. 1034; figured hypotype: Carnegie Mus. 5467 (on
same slab with Valcourea strophomenoides).

Horizon and locality—Common in the Crown Point formation in New York:
Crown Point, Port Henry (15’) Quadrangle; Plattsburg and Valcour Island,
Plattsburg (15’) Quadrangle ; Chazy, Rouses Point (15’) Quadrangle.

Same formation in Vermont: On Isle La Motte, Rouses Point (15’) Quad-
rangle.

St. Martin formation, Island of Montreal, Quebec, Canada.

Discussion.—This species is most like M. saffordi but is in general smaller in
size and somewhat more quadrate. It is also suggestive of M. plena from which
it differs in its stronger pedicle fold and brachial sulcus and its lesser convexity.
The species may be a composite one because the holotype is stratigraphically
younger than the New York specimens.

MULTICOSTELLA PLENA Cooper, new species
Plate 62, B, figures 6-14

Shell small for the genus, slightly wider than long, and with the greatest width
at about the middle. Cardinal extremities acutely to obtusely angular, rarely
auriculate. Both valves moderately convex, the brachial valve generally the
deeper. Anterior commissure rectimarginate. Surface multicostellate, 10 to 12
costellae occupying a distance of 5 mm. at the front.

Pedicle valve unevenly convex in lateral profile, with the greatest convexity in
the posterior half and the front half flattened or depressed. Fold nearly obsolete,
best developed in the posterior half. Flanks flattened and sloping gently away

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 423

from the median region. Interarea slightly longer than the brachial one, curved,
apsacline.

Brachial valve unevenly convex in lateral profile with a convex umbo but
gently convex midregion and anterior region. Sulcus deepest in the posterior
half, disappearing at about three-fourths the length from the beak. Flanks moder-
ately swollen. Slopes to cardinal extremities moderately steep.

Interior with pedicle muscle field short and narrow. Diductor scars not widely
divergent. Brachial valve having a small cardinal process.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FIGOLV DE te cles sesenee 14.0 13.8 15.8 13.7 6.5
Paratype (troqo3d)\...... 2. 15.4 14.5 16.4 13.0 7.9
% (rreqo2gy "Ss... 14.3 14.1 17.2 10.7 ? 6.9
ii CrrodoZztyn vr. os ES 15.3 14.4 16.1 12.8 6.9

Types.—Holotype: 110403e; figured paratypes: 110403b-d; unfigured para-
types: 110402a-e, 110403a,f; measured paratypes: 110402f,g.

Horizon and locality——Arline formation in Tennessee: North side of wagon
road in glade, + mile southeast of Friendsville, Concord (T.V.A. 138-SW)
Quadrangle.

Discussion.—This species is characterized by its small size (it and M. fascicu-
lata Butts are the smallest known species), its relatively strong convexity, par-
ticularly of the brachial valve, rounded outline, and narrow hinge. In these re-
spects it differs from known species.

MULTICOSTELLA PLICATA Cooper, new species
Plate 63, D, figures 22-29

Large for the genus, somewhat variable; wider than long with the greatest
width at the hinge in well-preserved specimens; sides nearly straight or gently
rounded; anterior margin broadly rounded; anterior commissure varying from
slightly uniplicate to slightly sulcate ; lateral commissure slightly deflected toward
the brachial valve at the cardinal extremities; brachial valve having a slightly
deeper profile than the pedicle one; cardinal extremities varying from slightly
acute to slightly obtuse, occasionally slightly auriculate; surface multicostellate,
costellae narrow, elevated, about equal in width to the spaces between them ; about
8 costellae in 5 mm. at the front margin of a specimen 21 mm. long; costellae pro-
duced in several generations ; costellae crossed by strong elevated fila.

Pedicle valve unevenly convex in lateral profile, most convex in posterior half
but convexity very low; anterior half gently convex ; anterior profile broadly but
slightly convex ; umbo narrowly convex, the convexity continued anteriorly as a
low fold perceptible in most specimens to the front margin, in a few fairly con-
spicuous; flanks bounding sulcus depressed convex; posterolateral extremities
deflected more or less strongly toward the brachial valve. Interarea moderately
long, strongly apsacline. Interior with short dental plates and shallow umbonal

424 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

cavities ; muscle area somewhat quadrate, gently indented anteriorly and extend-
ing about one-third the length; pallial impressions not strongly marked.
Brachial valve gently convex in lateral profile; broadly convex in anterior
profile and: with the median region more or less strongly indented. Umbo sul-
cate ; sulcus narrow and shallow to moderately deep in the posterior half, widen-
ing and shallowing, often to disappearance anteriorly; flanks bounding sulcus
somewhat narrowly rounded and with short but fairly steep lateral and postero-
lateral slopes. Interior with short, low median ridge, short brachiophores, and
stout but short cardinal process; lateral processes occasionally developed.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FIGIOLY Pe: fae 2 oetcaatea’s sees tas 21.7 21.5 26.0 22.0? 8.5
Paratype: (1104258) oy: tO. 25.5 24.8 31.2.7 ? 9.8
H (CBTO4Z5e) a saad ines 21.7 21.5 27.3? 23.4? 8.2
( TROAB SID a ais eiaicreain 21.1 20.8 28.7? 27.2 8.1
ff (11a4257)) [.1. .. goer 18.6 18.3 23.3 20.8 7.0

Types.—Holotype: 110414b,c (these are etched valves of one individual) ;
figured paratypes: 110414a, 110425b,e; unfigured paratypes: 110425a,c,d,f-i,
measured paratype 110425}.

Horizon and locality—Lincolnshire formation in Tennessee: 4 mile north of
Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle.

Discussion —This species is represented by numerous specimens, but not one
of them is perfect enough to permit the making of really good measurements.
The species is characterized by its large size, generally strong fold and fairly
deep and wide sulcus, although both features are variable. It differs from
M. quadrata in the stronger fold and sulcus.

MULTICOSTELLA QUADRATA Cooper, new species
Plate 63, C, figures 13-21

Shell large for the genus, slightly wider than long; hinge forming the widest
part; sides nearly straight ; anterolateral extremities rounded; anterior margin
truncated to gently rounded; cardinal extremities slightly auriculate; anterior
commissure rectimarginate ; lateral commissure very slightly deflected in the di-
rection of the brachial valve in the posterolateral region ; surface multicostellate,
costellae rounded and swollen, closely crowded with striae narrower than the
costellae ; costellae numbering 12 in 5 mm. at the anterior margin.

Pedicle valve unevenly convex with the most convex part in the posterior half
and with the anterior half flattened; anterior profile forming a broad triangle
with the median region narrowly rounded and the flanks sloping by a low descent
to the margins; umbo narrowly plicate to subcarinate, the carina continued to
the middle as a well-defined fold but becoming indistinct or obsolete anterior
to the middle; flanks slightly swollen and descending by a very gentle slope to
the margins ; posterolateral area small, flattened ; interarea moderately long, mod-
erately apsacline. Interior with small teeth; dental plates obsolete; muscle area

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 425

longitudinally rectangular, anterior gently indented medianly; muscle field ex-
tending nearly to middle ; diductor scars large; adjustor scars prominent. Pallial
impressions not strong.

Brachial valve moderately and fairly evenly convex; anterior profile broadly
convex and only slightly indented medianly ; umbo somewhat swollen, sulcate ;
sulcus narrow, moderately deep, extending to the middle; anterior half swollen
to obliterate sulcus or to make it indistinct. Flanks bounding sulcus moderately
swollen; posterolateral slopes short, gentle ; posterolateral extremities short and
flattened. Interior with fairly prominent median ridge occupying the posterior
third; notothyrial platform thickened; cardinal process slender; brachiophores
short and stout.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
BTOLOEV SiG ih ts Pele ot oes aie 19.6 19.0 23.0 23.3 8.0
1 GUTHOSOG) 5 siiara sas» vs 22.6+ 22.3 26.2 ? 7.8
§ A e° st hole) a eee 18.9 18.4 212 21.9 6.5
a COSTSoa Ee A. 15.5 15.8 18.2 17.9? 6.2
‘§ (O818Eb) ss 2). sles 25.5 25.9 ° 31.8 ? 8.7

Types.—Holotype: 116989a; figured paratypes: 98189a,c,g; unfigured para-
types: 98189b,d-f, 116989b-e.

Horizon and locality.—Whistle Creek formation in Virginia: On U. S. High-
way 60, 100 yards southeast of Whistle Creek, 2 miles northwest of Lexington,
Lexington (15’) Quadrangle; road along Purgatory Creek, 4 mile southwest of
the Dunkard Church, 6 miles north of Buchanan, Natural Bridge (15’) Quad-
rangle.

Ellett formation in Virginia: Ellett and Lusters Gate, Blacksburg (15’) Quad-
rangle.

Discussion.—This species is characterized by its subquadrate form and nearly
straight sides. It suggests M. plicata of the Lincolnshire formation but differs
in not possessing the strong fold and sulcus of that species.

MULTICOSTELLA RECTANGULATA Cooper, new species
Plate 61, B, figures 7-10; plate 64, B, figures 6-9

Shell of about medium size for the genus, transversely rectangular in outline;
sides gently rounded; anterior margin broadly rounded to slightly emarginate ;
anterior commissure rectimarginate; surface multicostellate, costellae crowded
and with striae narrower than the costellae which number about 12 to 13 in
5 mm. at the anterior margin.

Pedicle valve unevenly convex in lateral profile with the posterior half slightly
convex and the anterior half flattened; anterior profile broadly triangular, the
median part narrowly convex but low and with long, gently sloping sides; umbo
swollen narrowly, the swelling produced anteriorly to form a low but poorly
defined narrow fold extending to a point anterior to the middle; flanks flattened
and slightly depressed below the median elevation; posterolateral extremities
flattened and deflected toward the brachial valve. Interarea long, apsacline.

426 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve gently convex, most convex in the posterior half but flattened
anteriorly ; anterior profile broadly but gently convex; umbo sulcate, sulcus nar-
row and shallow to the middle, somewhat indistinctly defined in the anterior half;
flanks moderately convex; slopes to posterolateral extremities short and fairly
steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Flolotype oo 207. ETA 22.4 22.3 30.4 ? 8.7
Paratype (116990) .......... 19.7 20.6 26.6 ? 25.8 ? 7.0
i (T2RABE) ois caisyserry «(bys 11.4 wie 15.5 15.7 4.3

Types—Holotype: 116991; figured paratypes: 116990, 123456.

Horizon and locality.—Yellow limestone above 25-foot sandstone at base of
Eureka group in Roberts Mountains (1°) Quadrangle, Nevada: Saddle just
north of hill 8167, Martins Ridge, Monitor Range; 2 miles north of Martin
Ranch.

Discussion.—This species is characterized by its considerable width. In this
respect it differs strongly from M. parallela which occurs in the same region. It
is likewise wider than any of the described eastern species.

MULTICOSTELLA ROBUSTA Cooper, new species
Plate 63, B, figures 8-12

Shell small for the genus, wider than long with the hinge about equal to the
width at the middle; cardinal extremities approximately a right angle; valves
fairly strongly and subequally deep; sides nearly straight; anterior margin
broadly rounded; anterior commissure rectimarginate; lateral commissure
slightly deflected toward the brachial valve in its posterior part ; multicostellate ;
costellae closely crowded, unequal in size, about 13 in 5 mm. at the front margin.

Pedicle valve very gently convex in lateral profile; anterior broadly convex
with the greatest height in the middle but with long gentle lateral slopes ; umbo-
nal and median regions moderately swollen; fold only defined at the umbo;
lateral areas flat but gently swollen and with very gentle slopes to the margins.

Brachial valve unevenly and fairly strongly convex in lateral profile; pos-
terior half gently convex; anterior half somewhat abruptly flattened ; umbo swol-
len ; umbo sulcate, sulcus scarcely defined anterior to the middle. Median region
and flanks inflated ; slopes to posterolateral areas short and steep; posterolateral
regions small.

Measurements in mm.—Holotype, length 17.3, brachial length 17.2, width 20.6,
hinge width 17.6, thickness 7.3.

Types.—Holotype: 116992a; unfigured paratypes: 116992b,c.

Horizon and locality.—Lower part of the Sevier formation in Tennessee: 4
mile north of Gooseneck, Louisville (T.V.A. 138-SE) Quadrangle.

Discussion.—This species is characterized by its fairly small size, rectangular
form, crowded costellae, and thick cross section. It is somewhat suggestive of

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 427

M. semtsulcata but differs in details of the costellae, more robust cross section,
and more quadrate form.

MULTICOSTELLA SAFFORDI (Hall and Clarke)
Orthis ? saffordi Hatt and CLarKE, Pal. New York, vol. 8, pt. 1, pp. 218, 340, pl. 5A,
figs. 38-40, 1892.
Multicostella saffordi (Hall and Clarke) ScHucHERT and Cooper, Mem. Peabody Mus. Nat.
Hist., vol. 4, pt. 1, p. 98, 1932.

Although many specimens of Multicostella from eastern Tennessee appear in
the National Collection and that of the Geological Survey, it has proved impos-
sible to identify any of them with Hall and Clarke’s description of O. ? saffordi.
Inasmuch as their specimen could have come from any one of numerous horizons
and their description is so brief and noninformative, it is at present impossible
to identify the specimen except to be sure that it is a Multicostella. The speci-
men is said to have come from Knoxville, Tenn. This probably means that it
could have been derived from an area of several miles radius from Knoxville, an
area that includes beds from the Lenoir to the Sevier, but derivation from the
Arline formation seems probable.

Type.—Holotype: N. Y. State Mus. 7932/1.

MULTICOSTELLA SEMISULCATA Cooper, new species
Plate 64, D, figures 17-26; plate 71, G, figures 36-40

Multicostella saffordi SCcHUCHERT and Cooper, (not Hall and Clarke), Mem. Peabody Mus.
Nat. Hist., vol. 4, pt. 1, p. 98, pl. 8, figs. 23, 27, 1932.

Shell large for the genus, wider than long; hinge as wide or wider than the
width at the middle; valves subequally convex with the brachial valve slightly
the deeper; sides rounded; anterior margin broadly rounded; anterior margin
rectimarginate to broadly uniplicate; lateral commissure deflected toward the
brachial valve in the posterior part; surface multicostellate ; costellae and striae
about equal in width, costellae numbering about 8 in 5 mm. at the front of a
large adult.

Pedicle valve with unevenly convex lateral profile, the posterior half having
a greater convexity than the anterior half which is flattened; anterior profile
broadly triangular with the median area narrowly humped-up and with flat but
moderately steep slopes to the margins. Umbonal and posteromedian region swol-
len and forming a broad fold; anterior half somewhat flattened ; posterolateral
slopes long and gentle ; interarea moderately long, apsacline ; interior with muscle
field occupying posterior third.

Brachial valve moderately convex in lateral profile, broadly convex in anterior
profile; umbo gently swollen, sulcate; sulcus prominent but shallow in the pos-
terior half, not defined on the anterior half; median and anteromedian areas
somewhat swollen; slopes to margins gentle; interior with strongly thickened
notothyrial platform, stout cardinal process.

428 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FAGIOEO IS hn!s ates :5/0Pub ahce> mechs 14.2 13.5 17.5 15.7 5.2
Paratype (UEOASS ac sins ms 22.2 22.4 28.3 22.6 8.8

Types.—Holotype: 110474b; figured paratypes: 110433, I10474a,c,e; un-
figured paratype: 110474d.

Horizon and locality.—Lincolnshire formation (Hogskin member) in Tennes-
see: In Evans Ferry section about 1 mile north of Indian Creek on U. S. High-
way 25E, Howard Quarter (T.V.A. 162-NW) Quadrangle; 0.4 mile east-
northeast of Red Hill, Avondale (T.V.A. 162-SW) Quadrangle; 2 miles south-
west of Hall Crossroad, Fountain City (T.V.A. 146-SW) Quadrangle; Sally
Cleveland Farm, 3 mile southwest of Washburn, Dutch Valley (T.V.A. 154-SE)
Quadrangle ; 3 miles west-southwest of Thorn Hill, Avondale (T.V.A. 162-SW)
Quadrangle; Maynardville Pike, 1.7 miles north-northeast of Hall Crossroad,
Fountain City (T.V.A. 146-SW) Quadrangle; Raccoon Valley, 1 mile north of
Wilson, Briceville (30’) Quadrangle.

Lincolnshire formation in Virginia: At Speers Ferry, Clinchport (T.V.A.
188-NW ) Quadrangle.

Discussion—This species is similar to M. plicata from the closely related Lin-
colnshire formation but does not have the strong fold and sulcus so characteris-
tic of the Lincolnshire form. The shape and costellae help to separate M. semi-
sulcata and M. quadrata. Furthermore, the pedicle muscle field of M. quadrata
is much smaller than that of the other two species.

MULTICOSTELLA SULCATA Cooper, new species
Plate 71, A, figures 1-4

Shell of moderate size for the genus; wider than long with rectangular cardi-
nal extremities ; sides nearly straight ; anterior margin broadly rounded ; anterior
commissure nearly rectimarginate despite a narrow fold and sulcus; costellate,
costellae numbering 7 or 8 in 5 mm. at the front margin. Costellae with tendency
toward fasciculation.

Pedicle valve very gently convex in lateral profile; anterior profile very gently
convex but with a narrow median hump; umbonal region slightly swollen ;
median fold strong, subcarinate, narrow, extending from beak to anterior mar-
gin. Flanks bounding fold depressed to gently concave; interarea moderately
long, nearly catacline.

Brachial valve gently convex and of about the same depth as the pedicle valve
in lateral profile; anterior profile moderately convex with a deep and narrow
median groove; sulcus strong, deep, narrow, extending from umbo to anterior
margin. Flanks bounding sulcus forming narrow, strong plications; lateral
slopes short and steep. Interarea short, anacline.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
ELOLGEY Be ot hb Sieh yeas. eleeaiers A Stopes 17.1 17.1 20.5-+ ? 6.7

Paratype (pedicle valve) .... 16.9 r. 20.7 20.7 ?

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 429

Types.—Holotype: 116993; figured paratype: 110459.

Horizon and locality—Bromide formation (Mountain Lake member—Val-
courea transversa bed) in Oklahoma: In NE} sec. 1, T. 2 S., R. 2 W., 3 miles
east of Pooleville ; on Spring Creek in sec. 17, T. 2 S., R. 1 W., Murray County.

Discussion.—This species differs from all other described forms in the strength
of the pedicle fold and the deep brachial sulcus.

Genus CAMPYLORTHIS Ulrich and Cooper, 1942
Campylorthis ULtricH and Cooper, Journ. Paleont., vol. 16, No. 5, p. 621, 1942.

Shells wider than long, cardinal extremities varying from alate to obtusely
rounded. Lateral profile convexi-concave to unequally biconvex, the brachial
valve always the deeper. Anterior commissure varying from rectimarginate to
uniplicate. Interareas subequal in length, pedicle one generally apsacline ; brachial
interarea orthocline to anacline and usually extended posterior to the pedicle
beak. Surface multicostellate, costellae of unequal size; impunctate.

Pedicle valve with musculature of Dinorthis consisting of elongate, anteriorly
widening, and divergent diductor scars, moderately strong adjustor impressions
at the base of the dental plates, and small adductor field bisected by a low median
ridge. Muscle area square to elongate rectangular in outline. Teeth small but
with large fossettes ; dental plates short, stout, and receding, defining small umbo-
nal cavities. Pallial markings as in Dinorthis. Delthyrium covered.

Brachial cardinalia as in Dinorthidae; brachiophores short, rodlike, supported
by excess shell deposited on their inner surface. Cardinal process with short
shaft and narrow crenulate myophore in the young but with swollen and tri-
angular myophore in old specimens. Median ridge short, adductor field small.

Genotype.—Strophomena deflecta Conrad=Campylorthis deflecta (Conrad),
Proc. Acad. Nat. Sci. Philadelphia, vol. 1, p. 332, 1843.

Discussion—Campylorthis most nearly resembles Multicostella and possesses
a similar pedicle muscle arrangement and pallial marks but differs in profile.
Multicostella is biconvex in lateral profile, but Campylorthis has the pedicle
valve concave in the anterior half or two-thirds. In some individuals this con-
cavity is not strongly marked and differentiation from Multicostella is difficult.

The type species of Campylorthis was long ago assigned to the genus Val-
courea, and the common presence of a pseudodeltidium in the two genera made
this similarity striking. Nevertheless, an important difference in the cardinal
process of the two may be noted. That of Valcourea possesses a high median
ridge rising above the myophore, but the cardinal process of Campylorthis is
marked by no such ridge and the structure is like that of Dinorthis with a
crenulate myophore.

Campylorthis is also similar to Chaulistomella and differs from it only in the
possession of a pseudodeltidium. When Campylorthis was first proposed, the
name included the shells now referred to Chaulistomella, It seemed advisable to
separate the two, however, because true Campylorthis with the pseudodeltidium
seems to be confined to the Mississippi Valley region. Chaulistomella, some

430 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

species of which are close homeomorphs of Campylorthis, abounds in the Appa-
lachians.

Chaulistomella is a variable genus in its exterior form, some of the species hav-
ing the deeply concave pedicle valve similar to that of Campylorthis, but others
are more like Multicostella in exterior form. As far as known, none of them has
been found with a pseudodeltidium in place.

CAMPYLORTHIS DEFLECTA (Conrad)
Plate 69, A, figures 1-6

Strophomena deflecta Conran, Proc. Acad. Nat. Sci. Philadelphia, vol. 1, p. 332, 1843.

S. recta ConraD, ibid., p. 332.

Plaesiomys loricula Hatt and CLarKe, Pal. New York, vol. 8, pt. 1, pp. 197, 341, pl. 5A,
figs. 31-34, 1892.

For complete biblography, see Bassler, U. S, Nat. Mus. Bull. 92, p. 442, 1915.

Valcourea deflecta (Conrad) ScHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4,
pt. I, p. 97, 1932.

Shell fairly large, subelliptical in outline; hinge generally narrower than the
shell width at the middle; cardinal extremities acute in the young, obtusely
rounded in the adult; sides gently rounded; anterior margin broadly rounded ;
anterior commissure strongly uniplicate ; lateral margin strongly deflected toward
the brachial valve; surface costellate, costellae broadly rounded and separated
by striae narrower than the costellae; about Io costellae in 5 mm. at the front
margin of a large adult.

Pedicle valve unevenly concave in lateral profile, with the umbonal region
gently convex but the anterior two-thirds fairly deeply concave; anterior profile
broadly concave; umbo narrowly convex, the convexity extended anteriorly to
about the middle as a low fold; valve deeply sulcate anterior to the middle; flanks
deflected toward the pedicle valve and therefore concave; cardinal extremities
prominently deflected toward the brachial valve; interarea strongly apsacline to
catacline ; delthyrium covered by a large convex pseudodeltidium. Interior with
small teeth having deep fossettes; muscle field squarish in outline with promi-
nent adjustor scars at the base of the dental plates; diductor scars prominent;
pallial impressions not strongly marked.

Brachial valve unevenly convex in lateral profile, the umbo flattened, the
median region moderately convex and the front somewhat flattened; anterior
profile strongly convex with the greatest convexity in the median region and
with steep and abrupt lateral slopes. Umbo flattened but sulcate; sulcus nar-
row, shallow, extending to the middle where it disappears into a more or less
prominent fold of the anterior half; median and anterior regions forming a
broad fold with the flanks sloping strongly to the margins. Posterolateral areas
concave with outer side deflected toward the brachial direction. Interarea long
and flat, orthocline with a prominent chilidium. Notothyrial platform strongly
thickened; median ridge occupying the posterior third; brachiophores stout;
cardinal process moderately long and thick; pallial marks not deeply impressed.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 431

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (36101a).......... 18.4 19.4 25.2 22.5 6.3
ro ESOIGED) aasiceaie «oe 14.7 16.2 22.1 19.3 5.5
- Peoledver ae. s 1:3 12.8 17.0 18.0 4.4

Figured hypotype.—36101a; measured hypotypes: 36101b,c.

Horizon and locality.—Platteville formation (McGregor member) in Wiscon-
sin: At Highland, Iowa County; Mineral Point, Iowa County; Beloit, Rock
County ; quarry on Wisconsin Highway 81, 1 mile northwest of Ellenboro, Lan-
caster (30’) Quadrangle; Rocktown; Gratiot, Lafayette County; Janesville,
Rock County ; Pomeroy Quarry, River Falls, Pierce County; Dodgeville, Iowa
County; Argyle, Lafayette County; NE+ sec. 8, T. 3 N., R. 1 W., Platteville
Township, Grant County ; 0.1 mile south of the Little Platte River on Wisconsin
Highway 81, 2 miles northwest of Platteville, Lancaster (30’) Quadrangle.

Same formation in Minnesota: At Minneapolis.

Same formation in Illinois: At Dixon, 1.5 miles northeast of Dixon; Lee
County ; 3 miles above Savanna, Jo Daviess County.

Discussion.—This species has the appearance of a large and robust Valcourea.
In the young the cardinal extremities are angular and often auriculate. It is
probably to some young specimens that Conrad gave the name Strophomena recta
in 1843. Hall’s figures in Paleontology of New York, vol. 1, suggest a young
form.

Some variation is apparent in the concavity of the pedicle valve. A few speci-
mens show a nearly plane pedicle valve, but the majority of them indicate a
strongly concave pedicle valve and a folded, uniplicate brachial valve. These
features distinguish C. deflecta from C. subplana.

CAMPYLORTHIS SUBPLANA Ulrich and Cooper, new species
Plate 68, B, figures 5-12

Campylorthis deflecta UtricH and Cooper (not Conrad), Journ. Paleont., vol. 16, No. 5,
pp. 621, 622, 1942.

Shell of about usual size for the genus, wider than long; subelliptical to sub-
rectangular in outline; hinge narrower than the width at the middle in adults
but forming the widest part in young specimens; cardinal extremities alate in
the young but narrowly rounded in adults; anterior commissure gently unipli-
cate ; lateral commissure strongly deflected in the brachial direction at the cardi-
nal extremities ; surface multicostellate ; costellae broad and with striae narrower
than the costellae; about 10 to 12 costellae in 5 mm. at the front margin.

Pedicle valve unevenly convex in lateral profile, the umbonal region slightly
convex but the remainder gently concave, anterior profile broadly and gently
concave; umbonal region narrowly convex, the convexity continued to the mid-
dle as a low fold; anteromedian area depressed into a shallow sulcus; flanks
gently concave; cardinal extremities strongly and abruptly deflected toward the
brachial valve ; interarea long, nearly catacline; muscle field rectangular in out-

432 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

line, large; adjustor impressions moderately developed; diductor scars large;
dental plates short.

Brachial valve strongly convex in lateral profile with the maximum convexity
in the median region; anterior profile strongly convex and with steep slopes to
the margins; umbonal region flattened, sulcate, sulcus short, shallow, narrow,
extending to the middle ; median region, anterior, and flanks all swollen and with
steep lateral and anterior slopes. Notothyrial platform thickened ; cardinal proc-
ess slender; median ridge short.

Measurements in mm.—Holotype, length 20.2, brachial length 21.6, width 24.7,
hinge width 22.1, thickness 9.0.

Types.—Holotype: 1081992 ; figured paratypes: 108199b-d.

Horizon and locality—Plattin group (Macy formation) or Barnhart forma-
tion in Missouri: On old road 1 mile northwest of Chicago Summer School
Camp, NW4SW3 sec. 32, T. 37 N., R. 9 E.; on Fredericktown road 5 miles
southwest of Ste. Genevieve, Weingarten (15’) Quadrangle ; Rockwood’s Reser-
vation, 20 miles west of St. Louis on Manchester Road, 1 mile west of Grover,
St. Louis County.

Discussion.—This species is similar to C. deflecta (Conrad) in outline and
ornamentation but differs in having a much less concave pedicle valve, a less
strongly folded brachial valve, and much more strongly deflected cardinal ex-
tremities. The Plattin form is, furthermore, a much more robust shell with
greater depth and more strongly convex brachial valve.

CHAULISTOMELLA Cooper, new genus

Greek chauli, gaping; stoma, mouth)

This name is proposed for shells morphologically intermediate between Multi-
costella and Campylorthis. It is possible that the latter genus is more closely
related to Valcourea, but some of the species of Chaulistomella closely resemble
Valcourea and Campylorthis. Externally Chaulistomella is unlike Multicostella
in having the anterior half of the pedicle valve deeply depressed or concave. In
young forms or in a few species the resemblance to Multicostella is very strong
and the genera are difficult to separate. Inside the pedicle valve the musculature
is exactly like that of Multicostella, Campylorthis, and the rest of the Dinorthidae.

The brachial valve of Chaulistomella is always strongly convex, but the cardi-
nal process is not provided with a high median crest such as that of Valcourea.
In this respect it is like Campylorthis but differs from that genus in not having
a strong pseudodeltidium. The distinction between Multicostella and Chauli-
stomella is thus based on the concave pedicle valve; the distinction between
Chaulistomella and Campylorthis is based on the absence of a pseudodeltidium
in the former genus. Not only is the pseudodeltidium absent from Chaulistomella,
but no trace of it has been seen in any young specimens examined.

Genotype.—Chaulistomella inequistriata Cooper, new species.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 433

CHAULISTOMELLA BREVIS (Willard)
Plate 65, B, figures 7-12; plate 66, B,C, figures 10-27
Plaesiomys brevis WiLiarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 268,
pl. 1, figs. 12, 14, 1928.
P. platys Witiarp (not Billings), idem, p. 266, pl. 1, figs. 10, 11, 1928.

Shell subrectangular in outline, wider than long, hinge nearly a right angle
or extended slightly to have a width greater than that at the middle; cardinal
extremities often forming small ears; sides nearly straight or gently rounded ;
anterior margin broadly rounded ; anterior commissure rectimarginate to slightly
and broadly uniplicate. Surface multicostellate, costellae not strongly differenti-
ated, 10 to 14 in the space of 5 mm. at the front margin. Concentric fila strongly
developed, about 4 or 5 to the millimeter at the middle.

Pedicle valve unevenly convex in lateral profile, the posterior half very gently
convex but the anterior half gently concave. Umbonal region gently swollen,
somewhat narrowly swollen medianly with the swelling extended anteriorly as
a more or less well developed narrow fold. Anteromedian region flattened or
gently concave; lateral extremities deflected moderately in the direction of the
brachial valve. Interarea moderately long, strongly apsacline. Interior with
small, moderately indented muscle field; pallial trunks not strongly developed.

Brachial valve moderately convex in lateral profile with the greatest con-
vexity in the posterior two-thirds; anterior third somewhat flattened. Anterior
profile broadly and moderately convex; median region swollen; umbo gently
sulcate, sulcus disappearing before the middle; anterior and lateral slopes mod-
erately steep, fairly short. Interarea gently apsacline. Interior with short, thick
median ridge, thick notothyrial platform, and stout cardinal process.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (116995a)......... 25.1 26.1 31.2 30.5 8.2
= (i16904e)'..0.o. 20.4 21.0 25.2 22.8 6.8
¥ CTIOAG2D Pett. SAR 17.4 18.0 21.0 20.7 6.0

Types.—Holotype: M.C.Z. 8600c ; figured hypotypes: 110462b,d, 116994a-e,
1169952.

Figured specimen.—Plaesiomys platys Willard (not Billings): M.C.Z. 8598.

Horizon and locality—Benbolt formation and Benholt part of Dryden forma-
tion in Tennessee: 14 miles west of Lone Mountain; 14 miles northeast of Lone
Mountain, Tazewell (T.V.A. 154-NE) Quadrangle; 1.1 miles northeast of Lee
Valley, Lee Valley (T.V.A. 171-NW) Quadrangle; roadside 14 miles north-
east of Heiskell, Powell Station (T.V.A. 137-SE) Quadrangle; Liberty Hill
north of Lutrell, Dutch Valley (T.V.A. 154-SE) Quadrangle; hillside south of
Dutch; 4 mile southwest of Fleanor Mill, Powell Station (T.V.A. 137-SE)
Quadrangle.

Benbolt formation in Viriginia: At Fugates Hill north of Mendota, Bristol
(30) Quadrangle; south side of Mount Hagan School, southeast corner of the
northeast subquad., Hilton (T.V.A. 197-NW) Quadrangle; 100 feet above

434 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Echinosphaerites, on Virginia Highway 74, 54 miles east of its junction with
U. S. Highway 54 (Virginia 71) ; on Virginia Highway 71, 0.2 mile southwest
of Bethel Church, 4 mile east of the junction with U. S. Highway 54, Hilton
(T.V.A. 197-NW) Quadrangle; $ mile northeast of Speers Ferry; 14 miles
southwest of Rye Cove, Clinchport (T.V.A. 188-NW) Quadrangle; 1.2 miles
south of the middle fork of Moccasin Creek, 3 mile south of Hansonville, Han-
sonville (T.V.A. 205-SW) Quadrangle; 0.67 mile south of Tumbez, Moll Creek
(T.V.A. 196-SE) Quadrangle; north side of U. S. Highway 19, 13 miles south-
east of Hansonville Post Office, Brumley (T.V.A. 205-SE) Quadrangle.

Low in the Sevier formation in Tennessee: 4 mile northeast of Miser, Louis-
ville (T.V.A. 138-SE) Quadrangle.

Discussion.—This species is characterized by its very large size, its nearly flat
pedicle valve, and brachial valve of low convexity. The species was based by
Willard on two specimens which are immature forms. Furthermore, the speci-
men assigned by Willard to Billings’ species Multicostella platys is actually a
very fine large example of his C. brevis. This species is common in the Benholt
formation in its shaly facies in southwestern Virginia and adjacent northern
Tennessee.

The species is similar to C. inaequistriata, but the largest specimens are larger
than the largest of C. inaequistriata. It also differs from that species in having
more even-sized costellae, a less strongly developed fold, and less alate cardinal
extremities.

CHAULISTOMELLA CRASSA Cooper, new species
Plate 71, B, figures 5-9a

Shell of about medium size for the genus, wider than long with the hinge
slightly wider than the midwidth; cardinal extremities subalate; sides sloping
medianly more or less strongly ; anterior margin broadly rounded ; anterior com-
missure broadly uniplicate; surface multicostellate, costellae unequal in size,
strong and wide but separated by spaces slightly narrower than the costellae;
about 6 costellae in 5 mm. at the anterior margin.

Pedicle valve with uneven lateral profile, the umbonal region moderately con-
vex but the anterior two-thirds flattened to moderately concave; anterior profile
very gently convex; umbonal region slightly swollen but without distinctly
marked narrow fold; median region moderately concave; flanks bounding con-
cavity moderately swollen into a broad plication separating the concave median
region from the cardinal extremities which are deflected toward the brachial
valve. Interarea long and strongly apsacline. Muscle field of moderate size.

Brachial valve with uneven lateral profile, the posterior half fairly strongly
convex but the anterior half flattened. Median region swollen; umbo gently
swollen, slightly sulcate; sulcus indistinct or obsolete anterior to the middle;
lateral slopes long and gentle; anterior slope long and gentle; umbonal slope
steeper than the lateral slopes but fairly gentle. Interarea long and orthocline to
gently apsacline.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 435

Measurements in mm.—Holotype, length 15.8, brachial length 16.2, width 21.0,
hinge width 22.2, thickness 6.0.

Types.—Holotype: 116996a ; figured paratype: 116996b.

Horizon and locality—Bromide formation (Mountain Lake member—just
above bryozoan bed=Mimeila zone) in Oklahoma: On Oklahoma Highway gg,
3 miles south of Fittstown, Pontotoc County.

Discussion.—This is apparently a rare fossil because only two specimens have
been found in all the years of collecting in Oklahoma. It is chiefly characterized
by the coarse costellae which are stronger than those of any other species of this
genus for a shell of medium size. In form the species suggests C. superlata from
Georgia but differs in its stronger costellae and the distinct but broad uniplicate
anterior commissure.

CHAULISTOMELLA ELONGATA (Willard)
Plate 65, D, figures 18-20

Plaesiomys elongata WitiarpD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 267,
pl. 1, figs. 15, 16, 1928,

This is a rare species, and only a few specimens in all the collections of the
National Museum and the Geological Survey are referred to it. The figured
specimen has a somewhat more concave pedicle valve and a less convex brachial
valve than the type specimen, but the outline and ornamentation agree fairly well.

Types.—Figured hypotypes: 110473a,b.

Horizon and locality—Benbolt part of Dryden formation in Tennessee: At
Liberty Hill, north of Luttrell, Dutch Valley (T.V.A. 154-SE) Quadrangle;
100 yards west of the store at the juncture of Tennessee Highway 33 and the
Flint Creek road, Maynardville (T.V.A. 145-SE) Quadrangle.

CHAULISTOMELLA INAEQUISTRIATA Cooper, new species
Plate 65, A, figures 1-6; plate 68, C, figures 13-20; plate 69, C, figures 17-21;
plate 60, D, figure 22; plate 72, B, figures 6-13
Multicostella cf. M. platys (Billings) Butts, Virginia Geol. Surv. Bull. 52, pl. 90, figs. 37-48,
1942,

Shell of about usual size for the genus; wider than long ; widest part at hinge,
but in some the hinge is narrower than the midwidth; cardinal extremities gen-
erally acutely angular, often subalate, occasionally obtuse. Lateral margins con-
cave just anterior to the cardinal extremities but nearly straight to sloping medi-
ally anterior to the middle, but occasionally broadly rounded. Anterior margin
nearly straight to gently rounded. Anterior commissure varying from faintly
unisulcate to slightly uniplicate but generally rectimarginate. Lateral profile
varying from convexi-concave to convexiplane in the adults and generally un-
equally biconvex in the young forms. Surface multicostellate, costellae appear-
ing by implantation in 5 generations, and varying between 9 to I5 in 5 mm. at
the front. A few specimens show strong fasciculation of the costellae about the
ribs of the first generation.

436 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve in lateral profile gently convex in posterior half but gently to
moderately concave in the anterior half. Beak inconspicuous, umbo slightly
swollen ; fold variable extending anteriorly from beak to front margin or disap-
pearing in the anterior half. Fold generally marked by a median costella stronger
than surrounding ones. Region in front of cardinal extremities gently concave;
flanks of shell separating concave median area from cardinal extremities generally
gently convex. Interarea strongly apsacline to nearly procline, about equal in
length to the interarea of the brachial valve. Delthyrium open.

Brachial valve moderately convex in lateral profile; moderately convex in an-
terior profile with center sulcate. Sulcus originating and generally extending as
a shallow and narrow depression anteriorly to the front margin but disappearing
posterior to the front margin in some specimens. Flanks bounding sulcus gently
swollen with long gentle concave slope to cardinal extremities and with mod-
erate slopes to the anterior margin. Interarea long, orthocline to apsacline and
extending posterior to the pedicle beak.

Pedicle interior with muscle field about as long as wide, not deeply impressed ;
pallial marks not well developed. Brachial interior with short median ridge;
ponderous cardinal process and strong development of excess shell about the
cardinal process and brachiophores.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EVOMSEMOIE: 5 ik win nie tas si ibattinvwists cee 21.2 22.7 26.6 20.4 8.8
Paratype (110484a).......... 20.3 21.0 25.0 28.4 8.1
4 (104841). f 0 bc) 52 6.2 6.6 7.3 7.5 2.0
. (TIO4B4S). omrsag st. 3 8.1 8.3 II.4 12.4 3.0
% (1104840) sate an tee U7, 18.5 22.0 28.4 6.4
° (IOASAD) nce. 8 ety 23.0 24.5 20.7 32.4 ey}
* (OST Oa) Perrys ee 18.0 18.9 22.4 20.7 7.6
3 CHTOSIOR)Y ne 21.0 22.5 24.4 22.2 7.5

Types.—Holotype: 98212a; figured paratypes: 98212{,g, 110484b, 110488a,b,
110519a,f, 116997b, 116998a; unfigured paratypes: 98212b-e, 110484a,c-1,
11051Qb-e,g-t, 116997a,c,d.

Horizon and locality—Wardell formation (shaly facies) in Tennessee: 1.1
miles northeast of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle; 4
mile west of Dodson Creek on the road from Acuff to Tennessee Highway 33,
Maynardville (T.V.A. 145-SE) Quadrangle; valley west of Copper Ridge on
Rogersville-Sneedville road, Lee Valley (T.V.A. 171-NW) Quadrangle; 4 miles
northwest of Rogersville, Pressmens Home (T.V.A. 171-NE) Quadrangle;
Davis store west of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle.

Dryden formation on Tazewell (T.V.A. 154-NE) Quadrangle in Tennessee:
Lone Mountain to Tazewell road, 14 miles northeast of Lone Mountain; road
along Little Sycamore Creek, 0.35 mile northeast of Halls School.

Same horizon on Clinchport (T.V.A. 188-NW) Quadrangle in Virginia: At
Mannville School; 20 feet below top on U. S. Highway 58, 4 mile west of Danl-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 437

boone Yard on road from Gate City to Speers Ferry; Lloyd Carter’s barn, 0.8
mile northeast of school at Rye Cove; near new school at Rye Cove.

Discussion—This species is characterized by its unequal costellae, generally
well developed alate cardinal extremities, strong fold and sulcus for the genus,
and the generally compressed form. No other species has this combination of
characters. Chaulistomella superlata has some resemblance, but it is generally
a proportionally wider species and has a more concave pedicle valve. None of
the Oklahoma species is very similar because they have much more convex
brachial valves and are generally not so strongly alate.

This species is quite variable particularly in the hinge region. Some speci-
mens are fairly quadrate in outline and have nearly rectangular or obtuse cardi-
nal extremities. They are apparently extremes, prevented from developing their
normal alate form by overcrowded living conditions.

CHAULISTOMELLA LEBANONENSIS Cooper, new species
Plate 65, E, figures 21-30; plate 60, E, figure 23

Shell of about the usual size for the genus, about one-third wider than long.
Cardinal extremities approximately a right angle, usually strongly rounded.
Sides nearly straight or moderately strongly rounded; anterior margin gently
rounded to subtruncate. Anterior commissure broadly uniplicate. Surface multi-
costellate, 10 to 12 costellae occupying a space of 5 mm. at the front margin of
an adult. Costellae narrowly rounded and separated by furrows narrower than
the costellae.

Pedicle valve gently convex in the umbonal region but flatly convex anteriorly ;
fold varying from scarcely visible to fairly strong and extending from beak to
anterior margin. Anterolateral regions flattened. Interior with large quadrate
muscle area having large adjustor scars and large diductor impressions. Pallial
impressions not strong.

Brachial valve fairly strongly convex in lateral profile with the most convex
part in the posterior half; anterior profile strongly convex with steep, flattened
to slightly concave sides. Sulcus well defined to nearly obsolete. Posterolateral
slopes steep; cardinal extremities deflected. Interarea shorter than the pedicle
one, apsacline, not extended posterior to the posterior margin of the pedicle valve.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holptype 's. eses fie TPs 17.9 18.0 23.6 19.6 9.2
Paratype (pedicle valve 110533a).... 18.9 ? 24.9 22.5 ?
re [nS I re? Pe 17.0 17.3 21.8 ? 6.0

Types Holotype: 84024a; figured paratypes: 110523a, 110524a, 110533a,
110534a; unfigured paratypes: 27286a, 84024b, 110523b, 110524b, 110533b-e,
110534.

Horizon and locality—Lebanon formation in Tennessee: At Lebanon, Wilson
County ; Columbia, Maury Country: 3 miles east of Murfreesboro, Rutherford
County ; cut on U. S. Highway 41, # mile south of Knox Branch, 9 miles south-

438 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

east of Murfreesboro, Rutherford County; Rutherford Creek, 4 miles north of
Columbia, Maury County; near Clifton, Wayne County.

Carters formation in Alabama: At a quarry 4 mile north of Gate City, Leeds
(15’) Quadrangle.

Camp Nelson formation in Kentucky: At High Bridge, Harrodsburg (30’)
Quadrangle.

Discussion.—This species has a very strong resemblance to Campylorthis, but
not one of the numerous specimens in the collection has shown any trace of a
pseudodeltidium. The generally small size, fairly deeply concave pedicle valve,
and strongly convex brachial valve will help to place it. It resembles C. super-
lata from Georgia, but that is a larger and more coarsely costellate species. It
also resembles C. rectangulata from the Wardell formation in the Evans Ferry
section but differs in having a more concave pedicle valve and less swollen
brachial valve.

CHAULISTOMELLA MAGNA (Schuchert and Cooper)
Plate 70, B, figures 11-23
Dinorthis subquadrata DECKER (not Hall), Oklahoma Geol. Surv. Bull. 55, pp. 42, 46, pl. 13,
fig. G, 1931.
Valcourea magna SCHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1,
p. 98, pl. 10, figs. 16, 20, 27-29, 1932.

A large and robust species characterized by its size and beautiful ornamenta-
tion. Shell subquadrate in form and having the valves unequally convex, the
pedicle valve very gently convex while the brachial valve is moderately convex.
Fold low and poorly defined, from the beak to the front margin, but, as usual in
dinorthids, best defined on the posterior half. Flanks of shell bounding the fold
flattened or gently depressed.

Brachial valve much deeper than the pedicle valve and moderately convex in
lateral profile. Sulcus very shallow over its whole length but best defined at the
posterior half. Flanks bounding sulcus gently swollen. Interareas nearly of the
same length, the brachial one, however, slightly the shorter. Surface multicostel-
late, the costellae low and rounded, with unequal interspaces. Scattered primary
costellae often swollen and enlarged.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (110539c)........ 26.8 272 34.6 33.0 13.0
- (BIOGAS Ye has crates 25.8 26.0 34.0 31.9 12.3

Types.—Holotype: Y.P.M. (Schuchert coll.) 5779; figured hypotypes:
110539c, 110543a, 110545, 116999b; unfigured hypotypes: 110539a,b, 110543b-d,
1169992.

Horizon and locality—Bromide formation (Pooleville member—O-roplecia
gouldi zone) in Oklahoma: Rock Crossing of Hickory Creek, about center sec.
25, T.5 S., R. 1 E., Criner Hills, Carter County; West Spring Creek, east of
Pooleville, Murray County.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 439

Discussion—Chaulistomella magna (Schuchert and Cooper) is one of the
largest and most robust of described forms. It is further characterized by its
unequal costellation, its somewhat swollen pedicle valve, and its rectangular form.
It is very close to C. mitens from which it differs in its larger size, more unequal
costellae, and less strong sulcus. It is also suggestive of C. mira but differs in
having a more pronounced fold and sulcus and strongly differentiated costellae.

CHAULISTOMELLA MIRA Cooper, new species
Plate 61, D, figures 16-22

Shell large for the genus, length five-sixths the width; hinge narrower than
the greatest shell width which is slightly anterior to the middle; sides broadly
rounded; anterior margin broadly rounded; anterior commissure gently and
broadly uniplicate; lateral commissure with posterior strongly deflected toward
the brachial valve ; surface multicostellate ; costellae fairly uniform in size, sepa-
rated by very narrow striae; costellae numbering from 10 to 15 in 5 mm. at the
front margin.

Pedicle valve uneven in lateral profile, the posterior third nearly flat and the
anterior two-thirds flat to gently concave; anterior profile nearly a straight line
to very slightly concave ; umbonal region gently swollen; fold obsolete; anterior
two-thirds and lateral areas flat or barely concave; posterolateral extremities
gently rounded and deflected. Interarea strongly apsacline ; muscle field bilobate,
deeply impressed ; pallial marks not well developed.

Brachial valve strongly convex in lateral profile; strongly convex in anterior
profile and with long, steep lateral slopes; umbo swollen but without a median
depression ; median region strongly swollen and with steep lateral slopes; an-
terior slope long and not so steep as the lateral ones. Umbonal slopes steep to
the reflected posterolateral extremities. Brachial interior as usual for the genus.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Pralotyye Ware dood. ¢ 2oary 29.0 20.3 36.3 30.5 III
Paratype (pedicle valve 11700Ic).. 28.3 ? 34.2 30.0 4.4
4 (brachial valve 117001d). ? 16.9 31.9 27.1 ?

Types.—Holotype: 117001a; figured paratypes: 11700Ic,d; unfigured para-
type: I17001b.

Horizon and locality—Bromide formation (Mountain Lake member- cystid
bed) in Oklahoma: At the first dam on Spring Creek, N4 sec. 17, T.2S., R. 1
W., Murray County.

Discussion.—This species is characterized by its large size, fairly even costellae,
and poor development of fold and sulcus. The species is a large and robust one
like C. magna (Schuchert and Cooper) but differs in its subdued fold and sul-
cus, fairly uniform costellae, and the lesser development of pallial impressions.
It is a larger species than C. nitens which, however, has a well-defined fold and
sulcus.

440 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

CHAULISTOMELLA MUNDULA Cooper, new species
Plate 67, D, figures 24-29; plate 76, C, figures 15-17

Shell of large size for the genus, subrectangular in outline with the width
slightly greater than the length; cardinal extremities forming an obtuse angle;
sides oblique; anterior margin broadly rounded. Anterior commissure slightly
uniplicate ; lateral commissure deflected slightly in a brachial direction at the
posterior end. Surface multicostellate; costellae rounded, closely spaced, sepa-
rated by striae narrower than the costellae; about 11 costellae in 5 mm. at the
front margin. Concentric fila strong.

Pedicle valve unevenly convex in lateral profile, the posterior half nearly flat,
the anterior half gently depressed ; anterior profile very slightly convex ; umbonal
region slightly convex and with an indistinct fold fairly definitely visible in the
posterior third to half but barely perceptible or absent in the anterior half to
two-thirds. Median and anterior regions slightly swollen, the median region
slightly more convex than the anterior one; posterolateral extremities gently
deflected toward the brachial ; interarea long, nearly catacline ; muscle scars deeply
impressed, muscle field nearly equal in length and width; anterior indentation
moderately deep ; adjustor scars fairly large ; pallial marks only lightly impressed.

Brachial valve strongly convex in lateral profile with the greatest convexity in
the posterior half; anterior half flattened. Anterior profile strongly convex with
top somewhat flattened and short but steep lateral slopes. Umbo gently swollen,
faintly sulcate; sulcus fairly distinct in the median region but not reaching the
anterior margin; median region strongly swollen with steep anterior and lateral
slopes. Interarea long, apsacline.

Measurements in mm.—
Brachial Hinge
width

sength length Width Thickness
Foloty pest. |ccck Meee. aaa 23.4 25.0 27.0 23.1 T7,
Paratype (117000h) ........ 26.9 27.2 30.1 25.8 12.3

Types.—Holotype: 1170002 ; figured paratypes : 110442a,b, 117000e ; unfigured
paratypes : 117000b-d,f-h.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: In the east side of the road cut on Oklahoma Highway 18, 1.8 miles south
of Sulphur, Murray County ; deep well on Jones farm, sec. 22, T. 5 N., R.3 E,
Pottawatomie County, 3,240 to 3,244 feet, Midcontinent Petroleum Corporation
well.

Discussion—This species is characterized by its subquadrate appearance,
strongly rounded sides, narrow hinge, and robust form. Its contours are simi-
lar to those of C. quadrata but differ in the greater convexity of both valves and
the much larger size attained.

A pedicle and brachial valve from a deep well in Pottawatomie County is re-
ferred here. The pedicle valve agrees fairly well, but the brachial valve is some-
what wider proportionally than is usual in the species.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 441

CHAULISTOMELLA NITENS Cooper, new species
Plate 67, C, figures 17-23

Shell fairly large for the genus, wider than long; hinge about equal to the
midwidth ; cardinal extremities forming a right angle; sides straight; antero-
lateral extremities forming a right angle; anterolateral extremities and anterior
margin broadly rounded; anterior commissure rectimarginate; lateral commis-
sure deflected toward the brachial valve at its posterior ; surface multicostellate ;
costellae fairly even in size, separated by narrow interspaces, about 10 costellae
in 5 mm. at the front margin.

Pedicle valve unevenly convex in lateral profile with the posterior third flatly
convex and the anterior two-thirds nearly flat ; anterior profile nearly flat ; umbo
gently swollen, marked by a poorly defined fold extending to the front margin;
anterior half depressed ; flanks bounding depressed area faintly convex; postero-
lateral extremities more or less strongly deflected toward the brachial valve;
interarea moderately long, nearly catacline; muscle field fairly strongly im-
pressed, length and width about equal, moderately deeply indented anteriorly ;
adjustor scars small; diductor scars large; pallial marks lightly impressed.

Brachial valve fairly evenly and moderately convex in lateral profile; anterior
profile broadly convex; anterior commissure moderately convex, highest in the
middle; umbonal, median, and anterior regions fairly strongly swollen; lateral
slopes moderately long and steep ; umbo sulcate ; sulcus narrow, shallow, extend-
ing from umbo to anterior margin; interarea moderately long, fairly strongly
apsacline. Cardinal process stout; median ridge short; notothyrial platform
moderately thickened.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FIOLOLY Dey rae 6 Sei ase Mando ah 233 24.2 30.8 30.1 II.0
Paratype: (117003b)) .....05. «1 22.6 233 29.4 27.6 10.8

Types.—Holotype: 117003a; figured paratype: 117003c; unfigured paratype:
117003b.

Horizon and locality.—Bromide formation (Mountain Lake member) in Okla-
homa: On the east side of the road cut on Oklahoma Highway 18, 1.8 miles
south of Sulphur, Murray County.

Discussion.—This species is recognized by its transverse form and general
resemblance to C. magna (Schuchert and Cooper). It differs from the latter in
its smaller size, somewhat more concave pedicle valve and stronger fold and
sulcus. It is associated with C. mundula but is distinguished by its greater width
and stronger costellae.

CHAULISTOMELLA OBESA Cooper, new species
Plate 67, B, figures 8-16

Shell moderately large, length equal to about five-sixths of the width. Cardi-
nal extremities obtusely rounded, strongly deflected toward the brachial valve.

442 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Greatest shell width near the middle. Anterior commissure rectimarginate.
Valves covered by rounded costellae as wide or wider than the interspaces, about
7 to II costellae in 5 mm. at the front margin.

Pedicle valve in lateral profile gently convex. Median fold slightly developed
in the posterior half; umbonal region hemipyramidal, flattened in profile; slopes
to cardinal extremities moderate, front half flattened to slightly concave. Inter-
area long, strongly apsacline.

Brachial valve strongly convex in lateral and anterior profiles with the greatest
convexity at the middle. Sulcus shallow, originating at the beak and extending
to the front margin or lost just before reaching the margin. Median region of
valve strongly swollen in adults with steep slopes in all directions from the mid-
dle. Interarea moderately long, curved, apsacline.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype. 1a. teal. rede 18.7 18.8 23.2 21.2 8.9
Paratype (110561a) ......... 18.6 18.7 24.2 21.6 9.3

Types.—Holotype: 110562a; figured paratypes: 110561a, 117991a; unfigured
paratypes: 110561b-d, 110562b, 117991b,c.

Horizon and locality —Bromide formation (Mountain Lake member) in Okla-
homa: Sec. 25, T.2S., R. 1 E., 4 mile west of U. S. Highway 77; 3 miles north-
northeast of Springer, Carter County. Spring Creek, sec. 17. T. 2 S., R. 1 W.,
Murray County ; NW3 sec. 27, T. 1 S., R. 1 W., midway between Davis and
Dougherty, West Spring Creek, east of Pooleville, Murray County.

Discussion.—This species in its nearly biconvex valves strongly suggests the
closely similar genus Multicostella. Unlike that genus the pedicle valve is de-
pressed at the anterior half, and the fold and sulcus are short and obscure. The
species is finely costellate and differs from C. lebanonensis, which it approaches
in size, by its more convex valves. It is smaller than the other described Okla-
homa species except C. crassa to which it has no resemblance.

CHAULISTOMELLA RECTANGULATA Cooper, new species
Plate 69, B, figures 7-16

Shell of about medium size for the genus, rectangular in outline; wider than
long with the hinge forming the widest part or slightly narrower than width at
middle. Sides sloping obliquely in a median direction; anterior margin broadly
rounded ; anterior commissure rectimarginate to broadly uniplicate; surface mul-
ticostellate, costellae narrowly rounded, closely crowded, about 3 in I mm. at
the front margin.

Pedicle valve variable in lateral profile, posterior half flattened to gently con-
vex; anterior half depressed convex to flat; median fold indistinct and narrow,
fairly well defined on the umbo, indistinct in the anterior third; median region
flattened ; posterolateral extremities deflected slightly toward the brachial valve ;
interarea long, steeply apsacline to nearly catacline.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 443

Brachial valve strongly convex in lateral profile with the anterior slope flat-
tened but steep ; anterior profile strongly convex with steep lateral slopes ; median
region and umbo swollen; sulcus shallow and narrow, extending from umbo to
anterior margin but indistinct in the anterior third; lateral and anterior slopes
steep ; interarea short, steeply apsacline.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
ELGIOLYDE Ses cR ess Seats 18.1 18.2 23.7 25.2 9.0
Paratype (117005a) ........ 17.9 18.5 24.9 24.3 10.8

Types——Holotype: 117006; figured paratype: 117005a.

Horizon and locality—Wardell formation (Hesperorthis—Camerella beds),
Evans Ferry section in Tennessee: On U. S. Highway 25E, 4 mile north of
Indian Creek, Howard Quarter (T.V.A. 162-NW) Quadrangle; also just above
Hesperorthis at same locality as preceding; north side of the road, 1.1 miles
northeast of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

Discussion.—The species is characterized by its rectangular outline, flattish
pedicle valve, and strongly convex brachial valve. It resembles C. lebanonensis
in form and proportions but has a less concave pedicle valve and a much more
convex brachial valve. Its compact and strong form separate it from C. superlata.

CHAULISTOMELLA RIDLEYENSIS Cooper, new species
Plate 64, A, figures 1-5; plate 67, A, figures 1-7

Small for the genus, subquadrate in outline, wider than long with the hinge
forming the widest part or slightly narrower than the midwidth; sides concave
just anterior to the cardinal extremities, sloping slightly medianly near the mid-
dle; anterolateral extremities somewhat narrowly rounded; anterior margin
broadly rounded; anterior commissure uniplicate; surface multicostellate, cos-
tellae narrowly rounded, separated by spaces at least equal in width to the cos-
tellae; about 9 costellae in 5 mm. at the anterior margin of the brachial valve.

Pedicle valve with variable lateral profile; posterior third moderately convex
but anterior two-thirds flat to gently concave; umbonal region slightly swollen;
median region flat to concave; lateral areas flat to gently swollen; posterolateral
extremities deflected more or less strongly in the direction of the brachial valve ;
interarea long, strongly apsacline. Muscle field fairly deeply indented anteriorly
and with moderately large adjustor scars.

Brachial valve moderately convex in lateral profile; strongly convex in an-
terior profile with short and steeply sloping sides; median and anterior regions
strongly swollen; sulcus originating on the somewhat swollen umbo, extending
to the middle but indistinct on the anterior ; umbonal slopes short and steep. In-
terior with short brachiophores, moderately thick notothyrial platform, and large
erect cardinal process.

444 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype 278225. Renews 15.9 16.3 17.9 15.7? 8.3
Paratype (117008a) ......... 15.5 15.5 17.9 18.9 8.0

Types.—Holotype: 117007; figured paratypes: 117008a,b,f; unfigured para-
types: 117008c-e.

Horizon and locality—Ridley formation (lower third) in Tennessee: At east
side of Marshall Knobs, 5 miles south of Murfreesboro, Murfreesboro (15’)
Quadrangle.

Discussion —This is a small and compact species characterized by a quad-
rate form. It differs from all the other species with quadrate outline in its small
size. Large specimens are suggestive of C. lebanonensis but differ in their squarer
outline. The species is a rare one.

CHAULISTOMELLA SUPERLATA Cooper, new species
Plate 66, A, figures 1-9

Shell subrectangular in outline, wider than long and with a variable hinge;
sides gently rounded, slightly oblique ; anterior margin broadly rounded ; anterior
commissure rectimarginate; lateral commissure deflected toward the brachial
valve at the posterior ; surface multicostellate ; costellae uneven, about Io in 5 mm.
at the anterior margin.

Pedicle valve unevenly convex in lateral profile, the posterior third very gently
convex, the anterior two-thirds moderately concave. Anterior profile gently con-
cave. Umbo slightly swollen, subcarinate; fold narrow, fairly distinct in the
posterior region but becoming less distinct anteriorly, then becoming still more in-
distinct or obsolete; anterior two-thirds concave; flanks bounding concavity
forming a fairly prominent oblique fold; posterolateral extremities strongly de-
flected toward the brachial valve. Interarea long, catacline; muscle field deeply
indented anteriorly, deeply impressed and with fairly large adjustor scars. Other
pallial marks not distinctly impressed.

Brachial valve moderately strongly convex in lateral profile with the most
convex part in the posterior half; anterior half somewhat flattened. Anterior
profile strongly convex medianly but with fairly long and moderately steep lateral
slopes. Umbonal region swollen, sulcate ; sulcus shallow, distinct for two-thirds
the valve length, becoming indistinct or obsolete in the anterior third. Median
region swollen; lateral and umbonal slopes steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
ETOLOEY PEs wipigadslste oor. ARS 17.8 19.6 24.6 24.5+ 9.4
Paratype (110506b) ......... 15.0 16.6 20.4 20.4 7.0

Types.—Holotype: 110506a; figured paratypes: 110506b,d-f; unfigured para-
types: 110506c,¢.
Horizon and locality.—Ridley formation in Georgia: On U. S. Highway 27

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 445

just northwest of Chickamauga Creek, Kensington (T.V.A. 106-SE) Quad-
rangle.

Discussion.—This species has the outline and profile of Campylorthis and thus
suggests C. lebanonensis. It differs in being a much larger shell with stronger
ornamentation and somewhat less deep brachial valve.

CHAULISTOMELLA sp. 1
Plate 63, A, figures 1-7

The figured specimens are young because a brachial valve in the collection
is nearly twice the size of the complete specimen. The species is characterized
by its subquadrate form, the length and width being about equal. The sides are
subparallel ; the costellae are closely crowded with about 12 in 5 mm. in the young
complete specimen but 10 in 5 mm. at the front of the large brachial valve. The
pedicle valve is unusually convex for the genus, but that may be an indication of
the youth of the specimen. The brachial valve is strongly convex. The species
resembles C. mundula in outline but is a much more robust form with a more
convex pedicle valve. The immature complete specimen measures in mm.:
Length of pedicle valve 16.4, brachial length 16.5, width at middle 19.4, thick-
ness 7.9.

Figured specimens.—117990Aa,b.

Horizon and locality——Carters formation (O-xoplecia bed) in Alabama:
Quarry 0.3 mile north of Gate City, Leeds (15’) Quadrangle.

CHAULISTOMELLA (?) sp. 2
Plate 126, G, figures 36-40

Under this designation is placed a small lot of shells that may have other ge-
neric affinities. They are described because they occur in the Oranda formation
and may represent the end of a dinorthid line if correctly assigned. Proper ge-
neric definition will not be possible until the pedicle interior as well as the brachial
interior is known.

Small for the genus, subrectangular with the width greater than the length.
Sides rounded ; anterior margin broadly rounded; hinge narrower than the mid-
width. Exterior finely costellate and with the striae between the costellae occu-
pied by prominent concentric fila.

Pedicle valve moderately concave in lateral profile; broadly concave in anterior
profile. Umbo narrowly convex, the convexity continued anteriorly as a low
fold. Flanks bounding fold gently concave. Interarea long and strongly apsacline.

Brachial valve gently convex in lateral profile and with the maximum con-
vexity in the posterior half; anterior profile bilobed; sulcus originating at the
umbo, widening and deepening to the anterior margin where it occupies about
one-third the width. Flanks bounding sulcus somewhat narrowly convex; pos-
terolateral slopes short and steep; posterolateral extremities flattened. Cardinal
process slender ; notothyrial platform moderately thickened. Sockets deep, brachi-
ophores short and blunt.

446 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge

length Length Midwidth width Height Thickness
Pedicle valve (117000f).... ? 11.5 15.8 ? ? ?
Brachial valve (117009a).. 9.2 ? 13.5 10.7 ? ? B18

Figured specimens.—117009~,b,f.
Horizon and locality—Oranda formation in Virginia: In the railroad cut
4 mile east of Strasburg Junction, Strasburg (15’) Quadrangle.

Family PLECTORTHIDAE Schuchert and Cooper, 1931

Biconvex or convexi-concave Orthacea having a variable but usually some-
what cordate muscle area in the pedicle valve ; brachial valve having the brachio-
phores supported by convergent plates which unite with the floor of the valve
on each side of the cardinal process. Sockets defined by fulcral plates. Cardinal
process simple and usually having a compressed, crenulated myophore. Del-
thyrium and notothyrium usually unmodified.

Subfamily PLEcTORTHINAE Schuchert, 1929

Coarse and fine-ribbed Plectorthidae having wide hinge lines and unequal
interareas.

Genus DESMORTHIS Ulrich and Cooper, 1936

Desmorthis UtricH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 624, 1936; Geol. Soc.
Amer. Special Pap. 13, p. 158, 1938.

DESMORTHIS COSTATA Cooper, new species
Plate 50, J, figures 42-46

Shelli of about usual size for the genus, wider than long, with the greatest width
at about the middle; sides gently rounded; anterior margin broadly rounded;
anterior commissure rectimarginate. Surface costae, 36 along the margin of an
adult shell. One generation intercalated near the middle; costae narrow, sepa-
rated by spaces about equal in width to the width of the costae.

Pedicle valve gently convex in lateral profile with the greatest depth located
in the postumbonal region; anterior profile fairly strongly convex with the
median region somewhat narrowly rounded; umbonal and median regions swol-
len; lateral areas full and with short, steep slopes to the margins. Interarea
long, curved, apsacline.

Brachial valve with most convex part in the posterior region when viewed in
lateral profile; anterior profile broadly but gently convex. Umbo swollen; sul-
cus originating at the umbo, shallow, narrow but extending to the front margin.
Flanks bounding sulcus gently swollen; slopes to posterolateral extremities short
and steep.

Measurements in mm.—Holotype, length 5.9, brachial length 5.2, width 7.3,
hinge width 5.7, thickness, 2.5.

Types.—Holotype: 110813a.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 447

Horizon and locality.—Joins formation in Oklahoma: In SW} sec. 2, T.1 S.,
R. 1 W., about 4 miles east of Hennepin, Murray County; Falls Creek, Murray
County ; + mile west of Highway 77, sec. 25, T. 2 S., R. 1 E., Carter County ;
bed 3 of section, 1 mile west of Mill Creek, Johnston County.

Discussion—This species differs from D. nevadensis, also from the Joins
formation, in its stronger and more distant ribbing. Although D. costata has
some intercalated ribs, the surface is never as closely covered as in D. nevadensis.

DESMORTHIS NEVADENSIS Ulrich and Cooper
Plate 50, H, figures 35-39; plate 83, A, figures I-15

Orthis perveta Watcort (not Conrad), U. S. Geol. Surv. Mon. 8, p. 72, pl. 11, figs. 3, 3a, b,
1884.

Desmorthis nevadensis Utricn and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 159, pl. 30A,
figs. 1-16, 1938.

Types.—Holotype: 91344a; paratypes: 91344b-k, 91342a-d; complete speci-
men figured by Walcott as Orthis perveta: 17235; figured hypotype: 1108172 ;
figured specimen: 110806a.

Horizon and locality—Upper Pogonip group (Desmorthis zone) in Nevada:
At the west end of Lone Mountain, 18 miles northwest of Eureka, Roberts
Mountains (1°) Quadrangle.

Joins formation in Oklahoma: SW43 sec. 2, T. 1 S., R. 1 W., 4 miles east of
Hennepin, Murray County; Henryhouse Creek, Murray County; 4 mile west
of U. S. Highway 77, sec. 25, T. 2 S., R. 1 E., Carter County.

Genus PLECTORTHIS Hall and Clarke, 1892

Plectorthis HALL and CLARKE, Pal. New York, vol. 8, pt. I, pp. 194, 221, 1892——SCHUCHERT
and Cooper, Mem, Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 57, 1932.

PLECTORTHIS AUSTRALIS Cooper, new species
Plate 71, E, figures 21-26

Shell of about medium size for the genus, subquadrate in outline, slightly
wider than long; hinge narrow; greatest width at about the middle; sides and
anterior margin gently rounded; anterior commissure rectimarginate. Surface
marked by about 44 narrowly rounded, elevated costae intercalated in 2 genera-
tions and an incipient one appearing at the front margin.

Pedicle valve gently convex in lateral profile with the greatest convexity ap-
pearing just anterior to the umbo; anterior broadly convex with the median
region somewhat narrowly rounded ; umbo and median region somewhat narrowly
swollen; anteromedian region and flanks moderately inflated; lateral slopes to
margin long and moderately steep. Interarea short, curved, gently apsacline.

Brachial valve gently convex in lateral profile with the maximum depth occur-
ring at about the middle; anterior profile broadly and gently convex and with
median region depressed slightly into a shallow sulcus. Umbo moderately swol-
len; sulcus originating on the umbo, shallow, widening but not deepening to the

448 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

anterior margin where it is occupied by about 4 costae. Flanks bounding sulcus
gently swollen with short and gentle slopes to the margins.

Measurements in mm.—Holotype, length 12.7, brachial length 12.3, width 15.0,
hinge width 11.2, thickness 5.9.

Types.—Holotype: 117019a; unfigured paratypes: 117019b-f.

Horizon and locality.—Little Oak formation in Alabama: From a cut on U. S.
Highway 31, 4 mile north of Pelham, Bessemer Iron District (15’) Quadrangle.

Arline formation in Tennessee: Along wagon road in glade, + mile southeast
of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—This species is characterized by its subcircular outline, the scat-
tered and irregular intercalation, and the elevated, narrowly rounded costellae.
It is most suggestive of P. compacta from Tennessee but differs in having a much
more compressed profile, more slender costae, and less convex valves. A few
specimens from Friendsville, Tenn., agree with the Alabama species in the slender
character of the costae.

PLECTORTHIS COMPACTA Cooper, new species
Plate 84, B, figures 6-17

Shell of moderate size for the genus, width about one-quarter greater than
the length. Hinge narrower than the greatest shell width and about equal to
the length. Greatest width at about the middle. Cardinal extremities obtuse ;
lateral margins narrowly rounded; anterior margin gently rounded to nearly
straight. Surface costate, with 35 to 38 costae. The costae on the flanks turn
posterolaterally at about two-thirds their length from the beak. In the region
of the cardinal extremities a few costae are intercalated, and occasional costae
are intercalated on the body of the shell.

Pedicle valve strongly and evenly convex in lateral profile; broadly and gently
convex in anterior profile. The greatest convexity at the middle in both profiles.
Beak short and stout, incurved ; umbo swollen; umbonal slopes moderately steep ;
gently concave. Flanks and middle part gently swollen; fold defined only as a
gentle median swelling, usually inconspicuous. Interarea short, moderately
apsacline ; slightly curved. Muscle field heart shaped, dental plates well developed.

Brachial valve slightly less convex and deep than the pedicle valve; umbo
moderately swollen. Sulcus originating on the umbo and extending to the front
margin or scarcely defined. Sulcus, when present, shallow, widening anteriorly
and occupied by 3 to 6 costae. Flanks moderately swollen with moderately steep
and short slopes to the lateral margins and cardinal extremities. Interarea short
and curved, generally apsacline. Notothyrial cavity deep, cardinal process high,
slender, median ridge reaching the middle ; brachiophores short, curved ; brachio-
phore supports well developed.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PTGIOEVDE sass bares Ee Pie ta es 12.3 Diy 15.3 11.9 7.4
Paratype '(11082Is) 007... 15.3 14.5 18.5 14.0 9.1
re GrtoSert) att, 14.0 13.7 17.6 13.4 9.0

3 CTIOSZTIE) o.. oe 5 cisin ete 13.4 12.9 16.2 0.7 78

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 449

Types.—Holotype: 11082Ir; figured paratypes: 11082In,0,q,s; unfigured
paratypes: 110821a-m,p,t,u.

Horizon and locality—Arline formation in Tennessee: Along wagon road in
glade, 4 mile southeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle;
McMullens, Meadow (T.V.A. 139-NW) Quadrangle.

Discussion—This species is fairly common at Friendsville and can be recog-
nized by its compact form, strongly convex valves, and thick costae. The last-
named feature and the depth of the valves distinguish it from P. australis.
The species is suggestive of P. ponderosa in its compact form but does not reach
the large size of that species. It is quite unlike any other species described herein,
which in general remind one more of P. plicatella than the compact forms.

PLECTORTHIS LEBANONENSIS Cooper, new species
Plate 81, D, figures 15-17

Shell fairly large for the genus, wider than long; hinge narrow; valves un-
equally convex, the pedicle valve with the greater convexity. Sides gently
rounded ; anterior margin broadly rounded ; maximum width at about the middle.
Surface marked by about 30 narrowly rounded costae separated by spaces equal
to or slightly greater than the width of the costae, those of the brachial valve
slightly more distantly spaced than those of the pedicle valve. Interspaces marked
by fine, elevated threads.

Pedicle valve strongly convex in lateral profile with the greatest convexity in
the posterior region; anterior profile strongly convex; umbonal and median re-
gions inflated; lateral areas somewhat inflated and with moderately steep but
short slopes. Interarea curved, apsacline.

Brachial valve gently convex in lateral profile; broadly and gently convex in
anterior profile; sulcus originating at the umbo, shallow and extending to the
anterior margin ; flanks bounding sulcus gently swollen; lateral slopes moderately
long but gentle.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Laieiiei9 ¢ sila luge Seelam alpen «Ae jaar ? 10.2 8.4 he
Paratype ''(T10834a) 5.2.08. ? 8.7 12.0 IT. #2?

Types.—Holotype: 110834c; figured paratypes: 110834a,b.

Horizon and locality.—Lebanon formation in Tennessee: On Tennessee High-
way 16, 3.6 miles northwest of junction of Tennessee Highway 16 and U. S.
Highway 241, Shelbyville, Bedford County; quarry on U. S. Highway 41, 11.7
miles southeast of Murfreesboro, Rutherford County.

Discussion—The specimens on which this species is based leave much to be
desired, but the species is fairly distinctive in the slender and closely crowded
costae. Most of the specimens are young, but a few indicate that the species must
have reached an adult width of nearly 20 mm. The species is characterized, be-
sides the costae already mentioned, by the strongly convex pedicle valve and

450 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the gently convex brachial valve. In size it approaches P. transversa but differs
in having a less carinate pedicle valve and less transverse outline. It differs from
P. tenuis in possessing much stronger costae. It is also suggestive of P. pennsyl-
vanica but has a more convex pedicle valve.

PLECTORTHIS MAZOURKAENSIS Phleger

Plectorthis mazourkaensis PHuEcER, Bull. S. California Acad. Sci., vol. 32, pt. I, p. 9, pl. 2,
figs. 3-5, 1933.

Horizon and locality—Mazourka formation in California: Mazourka Canyon,
about 4 mile below the Lead Canyon trail, Inyo Mountains.

PLECTORTHIS OBESA Cooper, new species
Plate 92, F, figures 34-38; plate 260, A, figures 1-5

Shell large for the genus, subequally biconvex; hinge narrow; greatest width
at the middle; sides and anterior margin rounded; anterior commissure recti-
marginate ; surface provided with 27 narrowly rounded, elevated costae separated
by spaces wider than the width of the costae. Each costa bearing a double row
of pits on its surface.

Pedicle valve moderately convex in lateral profile, the median region somewhat
flattened but the anterior and posterior thirds convex. Anterior profile broadly
and moderately convex. Umbonal region swollen; entire valve inflated but with
steep posterolateral slopes. Interarea short, apsacline.

Brachial valve moderately convex but with the posterior and anterior thirds
somewhat abruptly curved. Anterior profile broadly convex with the median
region somewhat flattened and the sides short and steep. Entire valve inflated ;
sulcus originating on the umbo and extending to the anterior margin, shallow and
narrow and occupied by 2 costae. All slopes to the margins precipitous.

Measurements in mm.—Holotype, length 17.7, brachial length 16.9, width 19.2,
hinge width 13.4, thickness I1.9.

Types.—Holotype: 117020, figured paratype 124233a.

Horizon and locality—Dark shale under Eureka quartzite, in Nevada: Ridge
east of Martin Ranch; under 2 knobs of Eureka quartzite, north side canyon,
3.1 miles N. 32° E. of Blair (Segura) Ranch, Antelope Mountains, Roberts
Mountains (1°) Quadrangle.

Discussion—This species suggests P. ponderosa, but it does not attain the
large size of that species and is a thicker-shelled and much deeper species.

PLECTORTHIS PATULA (Phleger)

Plectorthis patulus Puuecer, Bull. S. California Acad. Sci., vol. 32, pt. 1, p. 10, pl. 2, figs. 1-2,
1933.

Horizon and locality—Mazourka formation in California: In Mazourka
Canyon, about 4 mile below the Lead Canyon trail, Inyo Mountains.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 451

PLECTORTHIS PENNSYLVANICA Cooper, new species
Plate 92, G, figures 30-44

Shell of about medium size for the genus, wider than long; hinge narrower
than the greatest width which is at the middle; sides narrowly rounded; anterior
margin broadly rounded; anterior commissure rectimarginate. Surface marked
by 29 narrowly rounded costae equal in width to the width of the spaces between
them. Interspaces marked by strong, distant fila.

Pedicle valve with gentle lateral profile having the maximum convexity at
about the middle ; anterior profile broadly convex and moderately humped in the
middle ; umbo somewhat narrowly swollen, the swelling extending to the middle
of the valve but lessening anteriorly ; flanks and lateral areas descending gently
to the margins. Interarea, short, curved, strongly apsacline.

Brachial valve very gently convex in lateral and anterior profiles; umbo sul-
cate, sulcus shallow from umbo to margin but widening broadly; sulcus occu-
pied by 4 costae. Flanks bounding sulcus gently swollen; lateral slopes long
and gentle.

Measurements in mm.—Holotype, length 10.6, brachial length 9.7, width 13.7,
hinge width 10.9, thickness 4.9.

Types.—Holotype: 11702I1a; unfigured paratype: 117021b.

Horizon and locality—Rodman member of Nealmont formation in Pennsyl-
vania: On the east side south quarry at Sparr, Huntingdon (15’) Quadrangle.

Discussion.—This species suggests the P. plicatella group of the higher parts
of the Trenton limestone. It differs from that species, however, in its proportion-
ately wider hinge, less convex valves, and more closely spaced costae. It is a
larger species than P. symmetrica with wider hinge, somewhat less numerous
costae, and proportionately less convex valves.

PLECTORTHIS PONDEROSA Cooper, new species
Plate 83, C, figures 22-32; plate 84, E, figures 24-32

Shell large for the genus, subquadrate in outline; hinge narrow; greatest shell
width at the middle; sides broadly rounded; anterolateral extremities narrowly
rounded; anterior margin gently curved; anterior commissure rectimarginate ;
surface marked by about 30 strong, direct costae.

Pedicle valve fairly strongly convex in lateral profile with the greatest con-
vexity just anterior to the umbo; anterior half somewhat flattened ; anterior pro-
file a broad arch; umbo and median region strongly swollen; lateral area swol-
len and with steep slopes to the lateral margin; interarea strongly curved, gently
apsacline. Muscle area small; diductor scars long and narrow; adductor track
moderately wide.

Brachial valve with gentle convexity in lateral profile, its depth considerably
less than that of the pedicle valve; median region swollen; sulcus shallow and
narrow, originating at the umbo and widening to the front margin where it is
inconspicuous. Flanks bounding sulcus broadly swollen; lateral slopes moder-

452 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ately broad and gently sloping to the margins. Cardinal process thick and bulb-
ous ; brachiophore plates short and stout.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype .shersisvhiiaitecs. 16.9 15.5 20.3 14.7 9.9
Paratype. (8 17O22D)) | ssa) o sts ee 20.4 19.0 24.4 17.9 12

Types.—Holotype: 117022a; figured paratypes: 110837a-d, 117022b; un-
figured paratype: 110837e.

Horizon and locality—Basal Martinsburg formation (basal part with Brongni-
artella referable to the Salona formation) in Virginia: On Virginia County
Highway 617=0910, 0.15 miles north of Green Mount Church, Broadway (15’)
Quadrangle.

Discussion.—This species can be readily recognized by its large size and coarse
costae. It is unlike any other species described in this monograph except P. obesa.
That species, however, is a much deeper one which, as far as known, does not
attain the large size of P. ponderosa.

PLECTORTHIS PUNCTATA Cooper, new species
Plate 84, D, figures 19-23; plate 84, F, figures 33-35

Shell small for the genus, wider than long; hinge narrow; valves subequally
convex, the pedicle valve having the greater depth; anterior commissure broadly
unisulcate ; sides rounded ; anterior margin somewhat truncated. Surface marked
by 31 costae at the front margin; some costae on the flanks bifurcating or inter-
calated. Costae bearing 2 rows of prominent pits.

Pedicle valve moderately convex in both profiles; median region swollen; lat-
eral slopes long and moderately steep. Brachial valve gently convex in lateral
profile ; broadly convex in anterior profile; sulcus originating at the umbo, widen-
ing anteriorly, prominent in the young, becoming shallow anteriorly and disap-
pearing in adults. Lateral regions swollen.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
TIOIGEV DE) 6c sss sins tunes seaphebes ? 8.1 11.0 7.8? 1.8?
| tg) Gk 3”) a ge a 6.0+ 6.4 8.5 6.2 aah

Types—Holotype: 110836a; figured paratypes: 117023b, 117024; unfigured
paratypes: 110836b, 117023a.

Horizon and locality —Tulip Creek formation in Oklahoma: On West Spring
Creek, NW} sec. 6, T. 2 S., R. 1 W.; NE corner sec. 1, T. 2 S., R. 2 W., 24
miles east of Pooleville, Murray County; first creek east of U. S. Highway 77,
SEXNELNE} sec. 25, T. 2 S., R. 1 E., Carter County. .

Discussion.—This species is similar to P. symmetrica in size and general form
but differs in having a more strongly convex brachial valve characterized by 2
rows of pits on each side of the costae.

PART! T CHAZYAN AND RELATED BRACHIOPODS—COOPER 453

PLECTORTHIS SYMMETRICA Cooper, new species
Plate 83, B, figures 16-21; plate 92, H, figures 45-50

Shell of about medium size for the genus, wider than long and with the great-
est width at about the middle. Hinge width about three-fourths the shell width.
Cardinal extremities obtuse. Lateral margins somewhat narrowly rounded; an-
terior margin broadly rounded. Surface costate; costae of pedicle valve slightly
wider than those of brachial valve, with interspaces slightly narrower than the
costae. Brachial costae narrower than those of the pedicle valve and the inter-
spaces slightly wider than the costae. About 32 costae. Interspaces marked by
occasional fine costellae and concentric fila. Surfaces of costae smooth.

Pedicle valve moderately convex with the greatest convexity in the umbonal
region ; anterior profile narrowly rounded medianly with moderate lateral slopes ;
umbo gently convex; beak broadly obtuse and protruding slightly posterior to
the posterior margin. Median region somewhat swollen; lateral and anterior
slopes moderately steep. Posterolateral slope to cardinal extremities slightly
concave and steeper than the slopes anterior to them. Interarea short, curved,
apsacline.

Brachial valve gently and evenly convex in lateral profile and with the great-
est convexity at about the middle; anterior profile with a gentle, shallow median
depression and slightly swollen flanks. Umbo sulcate; sulcus shallow, poorly
defined and extending for about one-half to three-quarters the valve length.
Flanks slightly swollen, posterolateral areas slightly flattened. Anterior half
somewhat flattened ; interarea short, orthocline.

Pedicle interior with short, narrowly divergent dental plates bounding a short
muscle field. Brachial interior with widely divergent, flat, and broad brachio-
phores braced by short, convergent brachiophore supporting plates. Cardinal
process low but with a hebertelloid myophore.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EUONOEG Cede tae cake ee riet ce tees 9.2 8.6 11.4 8.8 4.7
Paratype (110824b) ........... 8.4 8.2 II.0 8.8 4.8

Types.—Holotype: 110824a; figured paratypes: 110828a,d; unfigured para-
types: 110824b-f, 110828b,c.

Horizon and locality—Bromide formation (Pooleville member-Oxoplecia
gouldi zone) in Carter County, Okla.: At Rock Crossing of Hickory Creek,
near center sec. 35; T. 5 S., R. 1 EINWF'sec? 26, T. 5 S., R. 1 E.

Discussion—tThis species in its form suggests P. compacta, but it does not
reach the large size and rotund form of that species. The valves of P. compacta
are subequal in depth, whereas the brachial valve of P. symmetrica is shallow,
the pedicle valve having the greater depth. Comparison with P. pennsylvanica
is made under that species.

454 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PLECTORTHIS TENUIS Cooper, new species
Plate 81, E, figures 18-29

Shell large for the genus, slender in lateral profile; valves subequally biconvex
but the pedicle valve with the greater depth; hinge narrow; greatest width at
about the middle; sides somewhat narrowly rounded; anterior margin broadly
rounded; anterior commissure rectimarginate. Surface marked by about 42
narrowly rounded costae.

Pedicle valve with moderately convex lateral profile; anterior profile broadly
convex and not conspicuously swollen in the middle; umbonal region somewhat
swollen; median region swollen and with long gentle slopes to the lateral mar-
gins. Interarea short, apsacline, slightly curved; muscle field small, narrow;
diductor impressions deeply impressed ; adductor track slightly elevated.

Brachial valve with moderately convex lateral profile ; anterior profile broadly
convex and with a slight median depression. Sulcus originating on the umbo,
shallow and widening anteriorly to the front margin; occupied by 4 costae at
the front. Flanks bounding sulcus gently swollen; posterolateral slopes short,
moderately steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype: acces eeeiees ces ok 11.8 10.4 13.7 10.4 4.5
Paratype ¢€FE7O2Z7 Pee eee 15.8 15.6 22.3 15.0 6.8 ?

Types—Holotype: 117028c; figured paratypes: 117027, 117028a,b,d.

Horizon and locality—Benbolt formation (base) in Virginia: 0.2 mile south
of the middle fork of Moccasin Creek, 14 miles due south of Hansonville, Han-
sonville (T.V.A. 205-SW) Quadrangle; north side of U. S. Highway 19, 13
miles southeast of Hansonville Post Office, Brumley (T.V.A. 205-SE) Quad-
rangle; south side of Mount Hagan School, southeast corner of northeast sub-
quad., Hilton (T.V.A. 197-NW) Quadrangle.

Benbolt formation in Tennessee: 0.1 to 0.2 mile north of the road 1.1 miles
northeast of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

Discussion.—This species is characterized by its slender form and fine, numer-
ous costae. It is a fairly wide species and is thus suggestive of P. transversa, but
that species is more strongly costate. It is actually wider and longer than
P. compacta but is easily differentiated by its compressed profile and slender
costae.

PLECTORTHIS TRANSVERSA Cooper, new species
Plate 84, A, figures 1-5

Shell of about usual size for the genus, subelliptical in outline, lenticular in
profile, with narrowly rounded lateral margins and a very gently rounded an-
terior margin. Hinge equal in width to about two-thirds the maximum width
which is at the middle. Surface ornamented by 34 narrow, elevated, rounded
costae which appear in 3 generations by intercalation.

Pedicle valve in lateral profile most convex on the umbo and slightly posterior

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 455

to the middle of the valve. Anterior profile with flanks sloping gently away from
the swollen median region. Fold barely perceptible. Beak slightly incurved ;
interarea moderately long, apsacline, slightly curved.

Brachial valve with lateral profile having its greatest convexity at about the
middle. Sulcus originating on the umbo near the beak and extending to the front
margin where it is visible as a slight depression occupied by 5 costae. Flanks
bounding sulcus slightly swollen and lateral slopes of flanks to the posterolateral
margin short and consequently moderately steep.

Measurements in mm.—Holotype, length 13.2, brachial length 12.1, width
18.1, hinge width 12.4, thickness 6.3.

Types.—Holotype: 98181.

Horizon and locality—Arline formation in Virginia: Quarry at Marion,
Marion (T.V.A. 218-SE) Quadrangle; Ward Cove formation 0.4 mile northeast
of Jeff Gillespie’s in Thompson Valley, southwest of Tazewell, Pounding Mill
(15’) Quadrangle.

Discussion.—This species is characterized by its transversely elliptical out-
line. It approaches P. compacta in size but is more slender and less coarsely
costate. This species is also suggestive of P. plicatella of the Trenton but differs
in its slender profile and more slender costae.

PLECTORTHIS sp. 1

Three specimens from the Nidulites zone of the Chambersburg limestone indi-
cate a species suggesting P. lebanonensis in the form and ribbing of the pedicle
valve, but the brachial valve is shallow and contains numerous incipient intercala-
tions at the front margin.

Measurements in mm.—

Length Width
Pedicle -walve Ta7o2ba we. cdl es dar els Sy Ee 11.7 14.7
ESPACHIAN VALVE: TT7OZOD. 2595.0 sie 2s" > Sagapedaneasiahicauaiea sie =e ee 10.5 14.3

Described specimens.—117026a,b.

Horizon and locality Shippensburg formation (Pinesburg member-Nidulites
zone) in Pennsylvania: 34 miles north of Greencastle, Chambersburg (15’)
Quadrangle.

PLECTORTHIS sp. 2
Plate 84, C, figure 18

A Plectorthis of uncertain nature occurs in the chert of the Murfreesboro
formation at the type locality. The specimens consist of three partially buried
exteriors and the posterior end of a brachial interior which shows the character-
istic cardinalia. The specimens are so strongly silicified that accurate description
is not possible.

Figured specimen.—110835a.

Horizon and locality—Murfreesboro formation in Tennessee: From exca-
vation of new armory building at junction of west fork of Stone River and U. S.

450 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Highway 70, 14 miles northwest of Murfreesboro, Murfreesboro (15’) Quad-
rangle.

Genus DOLEROIDES Cooper, 1930

Doleroides Coorer, Journ. Paleont., vol. 4, pp. 375, 382, 1930.—SCHUCHERT and Cooper, Mem.
Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 63, 1932.

DOLEROIDES COMPRESSUS Cooper, new species
Plate 96, B, figures 22-38

Small for the genus, wider than long, broadly elliptical in outline; hinge nar-
rower than the midwidth; greatest width slightly anterior to the middle; sides
nearly straight and slightly oblique outward; anterolateral extremities narrowly
rounded ; anterior margin broadly rounded ; anterior commissure rectimarginate ;
surface multicostellate; costellae unequal in size, numerously intercalated and
usually fasciculate, 10 to 14 in 5 mm. at the front margin.

Pedicle valve with greater depth than the brachial valve, moderately convex
in lateral profile ; strongly convex in anterior profile with the median region nar-
rowly rounded; umbonal region narrowly swollen; median region swollen with
moderately steep and fairly long slopes to the margins. Interarea curved, apsa-
cline; muscle impression fairly long and with fairly wide diductor scars; dental
plates short; pallial impressions not preserved.

Brachial valve gently convex in both profiles and with the greatest convexity
in the median region. Sulcus originating on the umbo, short and shallow and
confined to the posterior half; sulcus barely perceptible on the anterior half of
the valve ; flanks gently inflated ; lateral slopes short and gentle. Cardinal process
a thin septum; notothyrial chamber moderately deep; brachiophores short; sup-
porting plates depressed.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EL OIG ty DE, on Paves Fons, Wn He 11.6 II.0 14.4 10.7 5.3
Paratype (110607b) ......... 10.8 10.3 12.9 0.8 5.4
a (rzo060sa)iie nus, 13.1 12.0 15.3 10.0 7.5

Types——Holotype: 110607c; figured paratypes: 110596a, 110607a,d-f; un-
figured paratypes: 110596b-h, 110605a, 110607b.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: On the east side of Oklahoma Highway 18, sec. 11, T. 1 S., R. 3 E., 1.8
miles south of Sulphur, Murray County.

Discussion.—This species is abundant in the road cut south of Sulphur but
was not seen at the same horizon on Spring Creek. The complete specimens
illustrated are adults, but they are young ones. The species evidently attains a
size nearly double that of the figured specimens but retains its compressed form
except for a few occasional obese specimens. The compressed form is the chief
characteristic of the species and differentiates it from the similar D. oklahomensis.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 457

DOLEROIDES CRASSUS Cooper, new species
Plate 95, A, figures 1-5

Shell of about medium size for the genus, subquadrate in outline; hinge nar-
row ; greatest width anterior to the middle; sides oblique outward ; anterolateral
extremities narrowly rounded; anterior margin broadly rounded ; anterior com-
missure rectimarginate. Costellae appearing in 4 generations; about 9 to I0
costellae in 5 mm. at the front margin.

Pedicle valve about equal in depth to that of the brachial valve; moderately
convex in lateral profile but with the anterior third somewhat flattened; beak
somewhat elongated; umbo not differentiated from the inflated median region;
sides somewhat inflated ; posterolateral slopes short and steep.

Brachial valve fairly strongly convex and with the maximum curvature at the
middle ; anterior profile broadly convex with a flattened median region and short,
steep lateral slopes ; median ridge shallow, narrow, and confined to the posterior
half; flanks moderately swollen; posterolateral slopes short and steep.

Measurements in mm.—Holotype, length 15.5, brachial length 14.7, width 18.3,
hinge width 13.2, thickness 9.0.

Types—Holotype: 110742b; unfigured paratype: 110742a.

Horizon and locality—Ridley formation in Georgia: from a road cut on
U. S. Highway 27 just northwest of Chickamauga Creek, Kensington (T.V.A.
106-SE) Quadrangle.

Discussion.—This species is characterized by its narrow hinge that differenti-
ates it from D. extensus with which it occurs. Its form is suggestive of that of
D. gibbosus of the Upper Mississippi Valley and Canada, but it differs from
that species in its rectimarginate anterior commissure, less deep valves, and some-
what stronger costellae.

DOLEROIDES EXTENSUS Cooper, new species
Plate 95, B, figures 6-20

Shell fairly large for the genus, somewhat rectangular in outline; wider than
long, with the hinge only slightly less than the midwidth; sides gently rounded ;
anterior margin broadly rounded ; anterior commissure rectimarginate ; costellae
thick, narrowly rounded, appearing in several generations and numbering about
II in 5 mm. at the front of the holotype.

Pedicle valve slightly deeper than the brachial valve, gently convex in lateral
profile; broadly convex in anterior profile with the median region somewhat
narrowly rounded ; beak low ; umbo somewhat inflated ; median region moderately
swollen ; lateral areas gently convex and with long, gentle slopes to the margins.
Interarea apsacline; interior with short and flaring dental plates; umbonal cavi-
ties shallow ; muscle field extending nearly to the middle, typical for the genus.

Brachial valve gently convex in lateral profile; anterior profile broadly convex
with gently depressed or flattened median region and short, steep lateral slopes ;
umbo and median region gently swollen; sulcus shallow and narrow, originating
on the umbo but extending only to the middle where it merges with the some-

458 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

what swollen anterior slope; lateral areas gently swollen; interior with thick
notothyrial platform and low median ridge.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Foletyne tat. dcmns <q taser it-> 15.5+ 14.7 19.7 17.2 7.6
Paratype (117031) 20 .2-+-+.% 12.2 11.5 16.0 12.9 7.0

Types.—Holotype: 117030; figured paratypes: 117031, 117032a,b.

Horizon and locality —Ridley formation on the Kensington (T.V.A. 106-SE)
Quadrangle in Georgia: On U. S. Highway 27 just northwest of Chickamauga
Creek; quarry on the west side of the road 14 miles south-southeast of Cove
Church, 5 miles south of Chickamauga.

Discussion.—This species is characterized by its transversely subrectangular
outline and strong costellae. It differs from D. regularis in its extended outline
and wide hinge as well as stronger costellae. It differs from D. winchelli Cooper
which is also a wide-hinged species in its almost complete lack of a fold and
sulcus and the rectimarginate anterior commissure. The species was seen only
in Georgia.

DOLEROIDES GIBBOSUS (Billings)
Plate 93, B, figures 8-14

Orthis gibbosa Brtuincs, Geol. Surv. Canada, Rep. Progress for 1856, p. 296, 1857.

Doleroides gibbosus (Billings) Coorer, Journ. Paleont., vol. 4, No. 4, p. 375, 382; pl. 35,
figs. 5-7; pl. 37, fig. 2, 1930.—Wutson, A. E., Geol. Surv. Canada Bull. 8, p. 49, pl. 3,
figs. 27a, b, 1946.

Subcircular to subelliptical in outline, lenticular in profile, the brachial valve
generally having the greater depth; hinge narrower than the greatest shell width
which is located at or anterior to the middle. Anterior margin broadly rounded,
lateral margins convex. Anterior commissure more or less strongly uniplicate.
Surface multicostellate, costellae subequal, 9 in 5 mm. in the sulcus; costellae on
the flanks alternating in size.

Pedicle valve moderately convex in lateral profile with the greatest convexity
located in the posterior half; sulcus originating anterior to the umbo, generally
wide and shallow but variable, some specimens having a fairly deep and narrow
sulcus. Flanks gently convex with steep slopes to the cardinal extremities, Inter-
area moderately long, apsacline.

Brachial valve evenly and moderately convex with the greatest convexity in
the median region ; anterior profile broadly convex with the midregion flattened.
Umbo marked by a shallow and narrow sulcus, usually indistinct ; fold originat-
ing posterior to the middle, low, flattened, often not distinctly marked from the
flanks except at the anterior. Flanks gently convex with steep slopes to the
margins,

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (110588a)........ 17.6 16.0 20.8 14.3 10.6
ff (aaz7aa ys eT. 16.4 15.4 19.3 14.0 10.7

" CZA774D) ooh eee 18.4 16.6 21.8 13.7 12.9

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 459

Types.—Figured hypotypes: 24772a, 24760; unfigured hypotypes: 24772b,
110588a.

Horizon and locality—Decorah formation (Spechts Ferry member) in Min-
nesota: At Fountain, Fillmore County; Chatfield, Fillmore County; St. Paul;
Minneapolis ; Elmira, Olmsted County.

Rockland formation in Ontario, Canada: At Gloucester and near Ottawa.

Rockland formation in New York: At Watertown and 1 mile east of Dexter.

Macy formation (Zell member) in Missouri: On the old road 1 mile north-
west of Chicago Summer School Camp, NW1SW43 sec. 32, T. 27 N., R.9 E.,
Weingarten (15’) Quadrangle.

Discussion.—This species is distinguished by its fairly large size and the strong
development of the fold and sulcus particularly in the anterior third or half. As
here identified the species is very variable as to outline and profile, development
of fold, and sulcus and ornamentation. As would be expected, variations in pro-
file are common and may have nothing to do with the biological characters of the
shells. Some of the specimens occur in soft shales and may be somewhat flattened.
Variations in outline are not generally due to distortion, and specimens in all
types of matrix showed a variation in the relation of length to width. Some
specimens are distinctly more rounded than others, and in the round ones the
cardinal extremities are generally much rounded, a feature that emphasizes the
rotundity of the outline. Some specimens are distinctly shouldered and have
cardinal extremities approaching a right angle. Most of the specimens referred
to this species have a fairly narrow fold and sulcus, but in a few of them, the
sulcus may occupy as much as half the shell width. Specimens of this type occur
in Minnesota and Ontario, but none was seen in the Plattin group. The Minne-
sota specimens vary from the Canadian ones in the character of the ornamenta-
tion, particularly the costellae occupying the sulcus. In the Minnesota forms
these costellae are generally nearly uniform in size, but in the Canadian speci-
mens a tendency to alternation of fine and strong costellae is present. Despite
these variations the writer was unable to find suitable differences on which to
base additional species.

DOLEROIDES IRREGULARIS Cooper, new species
Plate 95, E, figures 31-39

Shell small for the genus, wider than long, with the greatest width located an-
terior to the middle; hinge narrow; sides oblique outward; anterolateral extremi-
ties narrowly rounded; anterior margin nearly straight; anterior commissure
slightly uniplicate ; costellae unequal in size, those of the flanks finer than those
in the middle, about 12 in 5 mm. at the margin.

Pedicle valve somewhat less deep than the brachial valve and with unevenly
convex lateral profile, the posterior half fairly strongly convex, anterior half
flattened. Anterior profile broadly but fairly gently convex; beak prominent ;
umbo somewhat narrowly rounded; median region moderately swollen ; anterior
half to third depressed into a broad, shallow sulcus; flanks bounding sulcus

460 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

gently swollen and with short and steep lateral and posterolateral slopes. Muscle
scar narrowly rounded.

Brachial valve moderately convex in lateral profile, strongly convex and with
short, steep slopes in anterior profile; sulcus shallow and narrow, originating at
the umbo but indistinctly visible anterior to the middle; median and lateral areas
strongly swollen. Notothyrial cavity narrow, supporting plates somewhat erect,
median ridge wide, stout.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FAGIGEV PO he cara cclegis ccmeie eee 14.0 12.7 15.9 10.8 0.4
Paratype 9(110748).| shire sg «ape. 12.7 12.0 15.4 10.9 0.2
5a (TTIOSIOD) yas 2's 12.4 11.8 14.5 Li2 9.1

Types.—Holotype: 110648a; figured paratypes: 110510a, 118006a; unfigured
paratypes: 110510b, 110648, 110748, 118006b.

Horizon and locality—Dryden formation in Tennessee: 1 mile west of Lone
Mountain; Tazewell road, 14 miles northeast of Lone Mountain, Tazewell
(T.V.A. 154-NE) Quadrangle. Evans Ferry section along U. S. Highway 25E,
north of Indian Creek; 14 miles northeast of Halls School, Howard Quarter
(T.V.A. 162-NW) Quadrangle.

Discussion—This is a small, compact species occurring in the Wardell-Ben-
bolt=Dryden formation of the belts near the Cumberland Front. It has the
appearance of a small example of D. gibbosus but differs importantly from that
species. In general the sulcus of the Tennessee species is shorter than that of the
Minnesota form, and the brachial valve is deeper. This makes the Tennessee
species somewhat thicker than the Minnesota one. This species differs from
D. regularis in its narrower hinge and greater thickness as well as in its less
uniform character.

DOLEROIDES MISSOURIENSIS Cooper, new species
Plate 94, B, figures 4-8

Shell fairly large, resembling D. tennesseensis; wider than long with a mod-
erately wide hinge; sides rounded; anterior margin gently rounded; anterior
commissure with a broad uniplicate wave; costellae unequal in size, the larger
ones concentrated in the median region ; costellae about 10 to 12 in 5 mm. at the
front margin.

Pedicle valve unevenly convex, the posterior half moderately convex, the an-
terior half flattened. Anterior profile broadly but gently convex; posteromedian
region and umbo swollen; sulcus originating slightly posterior to the middle,
narrow, shallow, producing a small anterior tongue; flanks somewhat inflated
but with steep posterolateral slopes. Interarea long, apsacline ; muscle field large,
somewhat oval in outline; adductor track narrow; dental plates prominent.

Brachial valve moderately convex in lateral profile; strongly convex in an-
terior profile; sulcus originating on umbo, shallow, narrow, extending to a point
anterior to the middle ; anteromedian region somewhat swollen but without forma-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 461

tion of a distinct fold; flanks moderately swollen with moderately wide but steep
slopes. Interior with short, stout brachiophores and strong, well-defined support-
ing plates. Median ridge short, narrow.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve)........... 13.0 ? 16.0 12.9 5.0
Paratype ( “ SS PTOSRSM)!. a5 LEST ? 15.8 II.4 4.7
a (brachial valve 110582n).. =? 12.3 15.7 12.1 4.6

Types——Holotypes: 110582b; figured paratypes: 110582a,d,n; unfigured
paratypes : 110582c,e-m.

Horizon and locality—Macy formation (Zell member) in Missouri: Along
the old road 1 mile northwest of the Chicago Summer School Camp, NW4SW4
sec. 32, 1. 37 N., R.9 E., Ste.,Genevieve County.

Discussion—This species is suggestive of D. tennesseensis but is somewhat
more rounded than that species. It is also slightly more strongly costellate, has a
narrower pedicle sulcus and somewhat less abrupt brachial wave in the anterior
commissure.

DOLEROIDES OKLAHOMENSIS Cooper, new species
Plate 92, A, figures 1-4; plate 96, A, figures 1-21

Shell about medium size for the genus, wider than long with the hinge nar-
rower than the greatest shell width which is located slightly anterior to the
middle. Cardinal extremities obtuse, posterolateral margins straight, directed
obliquely away from the midline; anterolateral extremities narrowly rounded,
anterior margin gently rounded to nearly straight. Anterior commissure recti-
marginate or faintly uniplicate or sulcate. Multicostellate, costellae unequal in
size and appearing in about 4 generations and with a few scattered ones of larger
size; about 17 in 5 mm. at the front margin. On the anterolateral extremities
a tendency to fasciculation of the costellae is prominent. Costellae and interspaces
marked by fine concentric fila.

Pedicle valve most convex in the posterior half when viewed in profile; an-
terior half somewhat flattened in the same view. Umbonal and median regions
swollen and convex with moderately steep slopes to the cardinal extremities but
less steep slopes to the lateral margins; anterior slope gentle. Interarea nearly
procline, curved near the beak.

Brachial valve evenly and gently convex in lateral profile, broadly and gently
convex in anterior profile. Sulcus originating at the umbo and extending as a
narrow, Shallow depression to the middle of the valve and from thence appear-
ing as a wide, shallow or flattened space not affecting the anterior margin. Flanks
bounding sulcus slightly swollen; umbonal slopes moderately steep. Interarea
short, orthocline.

Pedicle interior with well-developed dental plates, elongate muscle field with
long slender diductor scars; pallial trunks not well developed. Notothyrial cavity
wide ; cardinal process stout ; brachiophores stout ; brachiophore supports low and
wide.

462 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
HMalaty pe 2. SOOO 11.0 10.6 13.5 9.6 6.6
Paratype (110603b).......... 11.8 11.4 13.8 7.0 7.8
os (106029) on Bon: os 10.9 10.3 13.6 10.0 6.3
wh ( TIOGGOR NK ....:,.:sitiaskad 12.0 Oe 14.5 II.0 7.0
"¢ (Tieoaeny 6... 5... 12.0 11.4 14.1 152 7.0

Types.—Holotype: 110603a; figured paratypes: 110600a, 110602b, 110603b,
110613, 117033c,d,g,h; unfigured paratypes: 110600b, 110602a, 117033a,b,e,f.

Horizon and locality—Bromide formation (Pooleville member-O-xoplecia
gouldi zone) in Oklahoma: In the quarry on the east side of Oklahoma High-
way 18, center NW} sec. 11, T. 1 S., R. 3 E., 1.8 miles south of Sulphur, Murray
County ; Rock Crossing of Hickory Creek, about center sec. 35, T.5 S., R. 1 E.,
Carter County; along U. S. Highway 77, SEJNE3 sec. 25, T. 2 S.,, R. 1 E,,
Carter County; Mountain Lake, E} sec. 22, T. 2 S., R. 1 W., Carter County.

Discussion.—This species resembles D. compressus from the Mountain Lake
member of the Bromide formation of Oklahoma but differs in its more elliptical
outlines, more convex valves, and different ornamentation.

This species, like D. compressus, had a somewhat rounded outline and is a
fairly small species. It is characterized by a rectimarginate commissure, a
tendency toward production of a sulcus in both valves, thus producing an anterior
emargination at the front. The species is most like D. compressus but differs in
its more robust form and deeper valves. It differs from D. pervetus in not pos-
sessing a strong pedicle sulcus and in having different ornamentation.

DOLEROIDES OTTAWANUS Wilson

Doleroides pervetus ottawanus Witson, Canadian Field-Nat., vol. 46, No. 6, p. 136, pl. 1,
figs. 3-5; pl. 2, figs. 14, 15, 1932; Geol. Surv. Canada Bull. 8, p. 49, pl. 3, figs. 28, 20, 1946.
D. pervetus Coorer, Journ. Paleont., vol. 4, No. 4, pl. 35, fig. 8, pl. 37, figs. 1, 3, 1930.

This species is described as intermediate in character between D. gibbosus and
D. pervetus. It can be recognized by its wider form and less strongly folded
commissure than in D. gibbosus and its larger size than that of D. pervetus.

Horizon and locality—Black River (Leray=Chaumont), at many localities
in the Ottawa and St. Lawrence Valleys.

Platteville formation in Wisconsin: At Highland, Iowa County.

DOLEROIDES PERVETUS (Conrad)

Orthis perveta Conran, Proc. Acad. Nat. Sci. Philadelphia, vol. 1, p. 333, 1843; Pal. New
York, vol. 1, p. 120, pl. 32, fig. 5, 1847.

Orthis (Dalmanella) subaequata var. perveta Conrad, WINCHELL and ScHUCHERT, Geol.
Minnesota, vol. 3, pl. 33, fig. 42 (only), 1893.

Doleroides pervetus (Conrad) Cooper, Journ. Paleont., vol. 4, No. 4, p. 381, pl. 36, figs. 4, 7,
1930.

Doleroides pervetus (Conrad) suggests a small edition of D. gibbosus which
it precedes stratigraphically. The shell is small for the genus and suggests

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 463

D. irregularis. It differs from the latter in its wider hinge, less convex and shorter
valves. Its small size and similarity to D. gibbosus will serve to identify the
species in the Mississippi Valley.

Horizon and locality.—Platteville formation (McGregor member) in Rock
County, Wis.: At Beloit and Janesville.

Same formation in Illinois: At Dixon, Lee County.

DOLEROIDES ? PONDEROSUS Cooper, new species
Plate 94, C, figures 9-18; plate 94, D, figures 19-21

Doleroides ? sp. Butts, Virginia Geol. Surv. Bull. 52, pl. 80, figs. 22-24, pl. 81, figs. 34-35,
1942.

Subrectangular in outline, with the width greater than the length; lateral mar-
gins broadly rounded, anterior margin truncated; cardinal extremities obtuse ;
anterior commissure broadly uniplicate. Surface costellate, costellae narrowly
rounded, elevated and with interspaces about equal in width to the costellae, 8
or 9 costellae in 5 mm. at the front margin, some standing out more prominently
than others.

Pedicle valve in lateral profile most convex in the posterior half and flattened
in the front half. Umbonal region convex, the convexity continued forward to
a point not quite at the middle ; posterolateral slopes long and steep. Sulcus broad
and shallow, originating at about the middle and occupying slightly more than
half the width at the anterior margin. Flanks flat in profile with moderately
gentle slopes to the margins. Interarea short, curved, apsacline. Beak incurved.

Brachial valve moderately and evenly convex in lateral profile with the maxi-
mum curvature at about the middle; strongly and broadly convex in anterior
profile. Umbonal region slightly convex, but anterior to the umbo and through-
out the median part to the front margin, the shell is fairly strongly swollen and
produces moderately steep slopes to the margins. Interarea short.

Pedicle interior with muscle area longer than wide and with narrow diductor
impressions ; thickened front margin with 2 short ridges anterior to it.

Measurements in mm.—
. Brachial Hinge

Length length Width width Thickness
TON OLS DE a oe fis iaie'n'« ols, 5,0 apn ialolsig 26.6 24.7 32.6 26.8 15.8
Paratype’ (110784) i... 25 27.6 25.6 33.8 26.0 ?

Types.—Holotype: 98225b; figured paratypes: 98225c, 110774, 110778a,
110784; unfigured paratypes: 98225a, 110778b,c; figured specimens: 118003a,c.
Horizon and locality —Effna formation in Virginia: At Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle; lower part
McNutt Quarry, 12 miles west of Bland, Burkes Garden (15’) Quadrangle.
Botetourt formation in Virginia: At the junction of Virginia Highways 731
and 724, 2 miles northwest of Brownsburg, Lexington (15’) Quadrangle.
Discussion—This species is unlike any other member of the genus so far
known in its large size and the alternating nature of the costellae. It was at first
thought to be referable to Mimella, but the character of the pedicle muscle field

464 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

excludes it from that genus. The scar is smaller than usual in Mimella. The
adductor scars are not elevated on a median callosity, but a low callus rim ex-
tends around the anterior margin of the field. Furthermore, a small ridge extends
for a short distance anterior to the median point of the muscle field.

The undistorted types figured, although large specimens, are not the largest
in the collections. A crushed individual from the locality northwest of Browns-
burg measures 36.5 mm. long and 37.5 mm. wide. The specimen is somewhat
lengthened and narrowed by the crushing, but in perfect condition the shell
would nevertheless be larger than any other specimen known.

DOLEROIDES REGULARIS Cooper, new species
Plate 95, C, figures 21-28

Shell small to medium size for the genus, subrectangular in outline; hinge
fairly wide but narrower than the midwidth; greatest width at about the middle;
sides rounded ; anterior commissure rounded; anterior commissure rectimargi-
nate; costellae narrowly rounded with interspaces about equal to the costellae,
about II in 5 mm. at the front margin; fasciculate along the margin, particularly
on the flanks.

Pedicle valve about equal in depth to the brachial valve, moderately convex in
lateral profile with the greatest convexity in the posterior half; anterior profile
broadly convex; umbonal and median regions swollen, somewhat flattened an-
teriorly ; lateral regions moderately convex and with long, gentle slopes to the
margins. Apsacline; dental plates strong, bounding moderately deep umbonal
cavities ; muscle field elongate, diductor scars long; adductor track with a short
anterior projection.

Brachial valve fairly strongly convex in lateral profile; broadly convex in
anterior profile and with median region somewhat swollen; sulcus originating
on the umbo, shallow and short, defined distinctly to the middle after which it
merges somewhat with the swollen anterior half. Median and umbonal regions
strongly swollen; lateral slopes steep and moderately long.

Measurements in mm.—Holotype, length 13.4, brachial length 12.9, width LS 9,
hinge width 13.9, thickness 8.6.

Types.—Holotype: 118005a; figured paratypes: 110646a,f; unfigured para-
types: 110646b-e; figured specimen: 110592a.

Horizon and locality—Wardell formation (top 40 feet) in Virginia: On Vir-
ginia Highway 610 at the southwest base of Paint Lick Mountain, Pounding Mill
(15’) Quadrangle.

Wardell formation in Tennessee: On the north side of the road 1.1 miles
northeast of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle. On U. S.
Highway 25E, 4 mile north of Indian Creek, Howard Quarter (T.V.A. 162-NW)
Quadrangle ; Nicely and Palmer’s store, 3 mile east of Kate, Maynardville (30’)
Quadrangle.

Pierce formation in Tennessee: At Murfreesboro.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 465

Dryden formation in Tennessee: Road along Little Sycamore Creek 4 mile
northeast of the west edge of Howard Quarter (T.V.A. 162-NW) Quadrangle.

Discussion.—This species is characterized by medium size, fairly regular form,
moderately strong costellae, rectimarginate anterior commissure, and moderately
wide hinge. It differs from D. irregularis in its wider hinge and less convex
valves. It suggests D. extensus but is not so strongly costellate and not so wide.
This species differs from D. tennesseensis in having more nearly equally deep
valves and a more regular outline.

DOLEROIDES TENNESSEENSIS Cooper, new species
Plate 93, C, figures 15-30; plate 94, A, figures 1-3

Shell of about medium size for the genus, wider than long, with the greatest
width anterior to the middle. Hinge narrow; cardinal extremities obtusely angu-
lar; sides slightly rounded in the posterior half but narrowly rounded at the
anterolateral extremities. Anterior commissure broadly uniplicate: Costellae of
unequal size, some swollen and hollow, appearing in 4 generations by intercala-
tion. The strongest costellae occupy the fold and sulcus where 2 narrow costellae
may appear between the larger ones and extend for a considerable distance with-
out expanding or swelling into normal size. From Io to 12 costellae occupy a
space of 5 mm. at the front margin of the fold and sulcus, while 14 to 16 costellae
of various sizes may be counted in 5 mm. on the flanks. All costellae perforated
by small scattered pits.

Pedicle valve moderately convex in lateral profile with the maximum con-
vexity in the posterior half; anterior profile broadly and gently convex. Sulcus
broad and shallow, usually originating near the middle and occupying from
slightly less than one-half to one-third the width. Umbonal region convex, in
some specimens distinguished as a low fold that may extend to about the middle
and in some specimens may be continued anteriorly as a low rounding of the
shell surface in the sulcus. Flanks gently convex with gentle lateral slopes but
with steeper posterolateral slopes to the cardinal extremities which are deflected
slightly toward the brachial valve. Interarea moderately long, curved, apsacline.
Beak pointed and incurved.

Brachial valve moderately and evenly convex in lateral profile with the great-
est convexity at about the middle; anterior profile moderately and somewhat
narrowly convex with the top of the curve flattened and the sides flat but de-
scending with fairly steep slopes. Umbonal region marked by a narrow and shal-
low sulcus which may extend to the front margin or disappear near the middle.
Sulcus impressed in a broad and poorly defined fold that is most pronounced in
the anterior half of the valve and is best seen on the anterior commissure. Flanks
flattened and with moderately steep slopes to the margins. Interarea short,
apsacline.

Interior: Pedicle muscle field elongate-oval in outline, not greatly widened
anteriorly with long and slender diductor impressions and a slightly elevated
adductor field. Adjustor impressions narrow. Dental plates short with shallow
umbonal cavities. Pallial impressions not preserved.

466 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial interior with moderately wide notothyrial cavity, moderately thick
brachiophores and supporting plates ; cardinal process slender ; median ridge low,
fairly slender.

Measurements in mm.—
Brachial Hinge

Length length Midwidth width Thickness
Rlolotyper coscwecese tte 13.8 13.0 177 13.9 8.9
Paratype’ (1r0635a). 9's: ae 14.5 13.7 18.3 12.0 9.8
ag (@T0G635e) eR eee 15.9 14.8 19.8 12.3 10.4

Types.—Holotype: 117034a; figured paratypes: 110628, 110635a,f, 110639¢,i;
unfigured paratypes : 110635b-e,g-], 110639a-d,f-h; figured specimens: 118002a-c.

Horizon and locality—Upper half of Lebanon formation in Tennessee: Be-
side U. S. Highway 41, $ mile south of Knox Branch, 9 miles southeast of Mur-
freesboro ; Columbia; 3 miles east of Murfreesboro; opposite Fairview Service
Station on U. S. Highway 70N, 11.6 miles east of Lebanon city limit, 2.5 miles
east of Wilson-Smith County line on U. S. Highway 70N; at east end bridge
over Round Lick Creek, Rome; 20 feet above Cryptophragmus on south side
U. S. Highway 70S, $ mile east of Readyville.

Cane Creek formation (95 feet above base) in Virginia: North of Chattels
Station Church, on old U. S. Highway 58, 2 miles west-southwest of Ewing,
Ewing (T.V.A. 161-NW) Quadrangle.

Carters formation in Alabama: At quarry 4 mile north of Gate City on Red
Mountain; Clifton Terrace, Birmingham, Leeds (15’) Quadrangle.

Discussion.—This species is characterized by its fine costellae, deep valves,
broadly uniplicate anterior commissure, and moderately wide hinge. This species
is readily separated from such other Tennessee species as D. crassus and D. ex-
tensus by its finer costellae. It differs from both Oklahoma species in its larger
size and more robust form. It is larger than D. pervetus and differently folded.
It is more finely costellate than the other Upper Mississippi Valley species. Its
closest relative is D. missouriensis from the Macy formation. It differs from that
species in lesser width, a stronger brachial sulcus, wider pedicle sulcus, and
broader plicate wave in the brachial valve. Doleroides tennesseensis is more
finely costellate, somewhat wider, and with less prominent brachial sulcus than
D. ottawanus Wilson.

DOLEROIDES WINCHELLI Cooper, new name
Plate 93, A, figures 1-7

Orthis media N. H. WINcHELL (not Shaler, 1865), 8th Ann. Rep. Minnesota Geol. Nat. Hist.
Surv., p. 64, 1880.

Large for the genus, wider than long and subrectangular in outline; sides
rounded ; anterior margin nearly straight; anterior commissure strongly unipli-
cate ; costellae strong, those on the fold and sulcus slightly stronger than those
of the flanks; about 8 costellae in 5 mm. in the median region and about 10 in
5 mm. at the flanks, both counts taken at the anterior margin.

Pedicle valve with unevenly convex lateral profile, the posterior half moder-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 467

ately convex but the anterior half somewhat flattened. Anterior profile almost
flat to broadly and gently convex ; umbonal region swollen, sulcus originating at
about the middle, broad and shallow at its origin but widening and deepening to
the anterior margin where it occupies nearly half the width; flanks bounding
sulcus gently convex ; posterolateral extremities narrowly convex and with steep
slopes, and strongly deflected toward the brachial valve. Interarea long, curved,
apsacline. Muscle field long with subparallel sides ; adductor track wide at front ;
diductor scars long and narrow.

Brachial valve deeper than the pedicle valve, gently convex in lateral profile,
strongly convex in anterior profile. Fold originating at about middle, low and
wide and only moderately elevated ; flanks gently convex ; posterolateral extremi-
ties gently sulcate ; lateral slopes steep.

Measurements in mm.—Hypotype (110578a), length 17.0, brachial length
15.3, width 20.8, hinge width 15.8, thickness 10.0.

Types.—Figured hypotypes: 110578a,b.

Horizon and locality.—Decorah formation (Spechts Ferry member) in Min-
nesota: At Fountain, Fillmore County.

Same formation in Wisconsin: At Highland, Iowa County; 2 miles west of
Platteville, Grant County.

Discussion.—This species is characterized by its large size, wide hinge, promi-
nent and somewhat elevated fold, and strongly uniplicate anterior commissure.
It differs from D. gibbosus with which it has been confused in the character of
the brachial fold and the abbreviation of the brachial sulcus. In D. winchelli the
sulcus on the brachial valve is narrow and shallow and extends anteriorly to
about the middle. It is also independent of the fold on which it occurs. In
D. gibbosus, on the other hand, the fold is rather a broad but strong wave of the
anterior commissure, but the sulcus originates at the beak, is shallow, extends
anteriorly, widening in the same direction to the anterior margin, where, how-
ever, it does not affect the commissure. The pedicle sulcus is also more pro-
nounced in D. winchelli than in D. gibbosus. The name Orthis media was pre-
occupied, therefore the name D. winchelli is proposed.

DOLEROIDES sp. 1
Plate 95, D, figures 29, 30

Shell large for the genus, subrectangular in outline, wider than long; costellae
fairly even, 10 to 11 in the space of 5 mm. at the anterior margin; costellae with
fine scattered pits on surface.

Pedicle valve with swollen umbo and median region; sulcus occupying anterior
third, shallow but wide; flanks gently convex ; interarea long, apsacline. Muscle
field small, narrowly elliptical in outline.

Brachial valve moderately convex in lateral profile; strongly convex in an-
terior profile; sulcus scarcely defined, not reaching the margin; median and
lateral regions swollen ; lateral slopes short and steep.

Measurements in mm.—Pedicle valve, length 14.7, width 18.9.

468 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Figured specimens.—118004a,b.

Horizon and locality—Pierce formation in Tennessee: At Pierce Mill, on
Tennessee Highway 10, just south of Walterhill, 74 miles north-northeast of
Murfreesboro, Rutherford County.

Genus MIMELLA Cooper, 1930

Mimella Cooper, Journ. Paleont., vol. 4, No. 4, p. 375, 1930.—SCHUCHERT and Cooper, Mem.
Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 61, 1932.

Mimella can be recognized by its generally hebertelloid outline, but its pedicle
valve is usually more convex than that of Hebertella. The pedicle muscle scar
of Mimella is the most important and diagnostic feature of the genus. This is
characterized by subparallel or divergent, elongate and deeply sunk diductor
tracks separated by an elongate and usually anteriorly expanded and elevated
adductor track. The brachial interior is like that of the rest of the hebertelloids.

Small distinctions are possible between Marmor and post-Marmor Mimellas.
The earliest forms generally are rectimarginate, but they also have a fairly
strongly pronounced sulcus in the umbonal and median regions. Generally the
sulcus does not reach the anterior margin. Post-Marmor Mimellas are often
umbonally sulcate, but the anterior commissure is usually broadly uniplicate.
The folding of the anterior commissure is usually confined to the marginal region
of the valves because no species is known with a strong and pronounced median
fold on the brachial valve. These features are of some help in sorting the species
stratigraphically.

A note on the genotype of the species is important. When the genus was
established, Cooper cited Pionodema globosa Willard as the type species. Willard
also described Hebertella melonica which belongs to the genus Mimella. The
results of the present studies indicate that these two species are the same. It
seems best, therefore, to put H. melonica in the synonymy of M. globosa be-
cause the latter species was selected as the type of the genus.

Mimella, according to present studies, appears first in the middle of the
Chazyan (Crown Point) and extends into the Wardell formation. The genus
is abundant in the Benbolt formation where it attains a large size. Doleroides
appears first in the Dryden formation and becomes fairly common in Wardell
rocks. In still higher rocks of the lower Trentonian, Doleroides is the abundant
hebertelloid.

MIMELLA BICONVEXA Cooper, new species
Plate 87, C, figures 16-19

Large, wider than long, transversely elliptical in outline; hinge narrower than
the greatest width which is at about the middle. Cardinal extremities obtuse.
Anterior commissure gently uniplicate. Surface covered by nearly uniform, fine
costellae about 14 in 5 mm. at the front. Costellae exopunctate.

Pedicle valve with lateral profile fairly evenly convex with the maximum con-
vexity near the middle. Sulcus originating at about the middle, narrow and

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 469

shallow and producing a small tongue. Flanks slightly convex with fairly steep
posterolateral slopes and moderately steep anterior and lateral slopes. Interarea
short, curved, apsacline. Delthyrium narrow.

Brachial valve strongly convex in lateral profile with the maximum convexity
at about the middle. Anterior profile also strongly convex, this valve having
greater depth than the pedicle one. Fold visible only as a wave of the anterior
margin in the brachial direction. Median region inflated, with steep slopes to all
the margins. Umbonal region somewhat inflated. Interarea short and slightly
apsacline.

Interior of the pedicle valve with a broadly triangular muscle field having a
wide adductor track.

Measurements in mm.—Holotype, length 18.6, brachial length 18.2, width 27.0,
hinge width 19.0, thickness 16.6.

Types.—Holotype: 48755a; figured paratype: 110652a.

Horizon and locality—Pierce and Ridley formations in Tennessee: At
Murfreesboro.

Discussion.—This species attains a large size and is characterized by its inflated
valves, gentle contours, and fine costellae. It is a rare species, at present known
from the Pierce and Ridley (?) limestones of the Central Basin of Tennessee.
In size this species suggests M. globosa, but it is actually smaller than the larg-
est of that species. Furthermore, the exterior contours and profiles are quite
different, the East Tennessee species being much less inflated.

MIMELLA BOREALIS (Billings)
Plate 85, E, figures 38, 39
Orthis borealis Bittincs, Canadian Nat. Geol., vol. 4, p. 436, fig. 14, 1859.—LeEsLEy, Geol.

Surv. Pennsylvania, Rep. P 4, p. 510, figs., 1880.
Hebertella borealis (Billings) RaymMonp, Ann. Carnegie Mus., vol. 7, p. 241, figs. 13, 14, IQII.

Types.—Holotype: G.S.C. 1035¢.
Horizon and locality—St. Martin formation in Quebec Province, Canada:
Caughnawaga, La Prairie County.

MIMELLA COSTELLATA Cooper, new species
Plate 91, A, figures 1-7a

Shell small for the genus, subelliptical to subrectangular in outline; sides
rounded, anterior margin subtruncate. Hinge narrower than the greatest shell
width which is at about the middle. Anterior commissure broadly uniplicate ;
lateral commissure deflected toward the brachial valve near the cardinal extremi-
ties. Surface evenly and finely costellate, 20 costellae in a space of 5 mm. at the
front margin.

Pedicle valve strongly convex in posterior half but flattened anteriorly when
seen in lateral profile. Anterior profile moderately convex with the greatest con-
vexity in the median portion. Umbonal region strongly convex. Sulcus shallow
and narrow, not conspicuous and originating near the middle. Flanks flattened

470 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

to slightly concave and with gentle anterior slopes but moderately steep pos-
terolateral slopes. Interarea strongly curved, apsacline. Beak prominent and
incurved.

Brachial valve about equal in depth to the pedicle one, with a fairly strongly
convex lateral profile with the posterior half swollen. Anterior profile strongly
convex and with steep lateral slopes. Fold imperceptible; the entire median
region somewhat swollen with an inflated umbo and steep posterolateral and
lateral slopes. Anterolateral slopes moderately steep. Interarea curved, apsacline.

Measurements in mm.—Holotype, length 11.6, brachial length 11.0, width 14.7,
hinge width 10.5, thickness 8.1.

Types—Holotype: 110658a; figured paratype: 110658b.

Horizon and locality—tLincolnshire formation (Hogskin member) in Ten-
nessee: I mile southeast of Washburn, Dutch Valley (T.V.A. 154-SE) Quad-
rangle; Inskip, Fountain City (T.V.A. 146-SW) Quadrangle; Eidson, Kyles
Ford (T.V.A. 170-SE) Quadrangle.

Discussion.—This species is characterized by its generally small size and its
finely costellate exterior. It differs from M. similis, also occurring in the Hogskin
shale, by its more swollen valves, particularly the pedicle valve, and its finer
ornamentation.

MIMELLA EXTENSA Cooper, new species
Plate 86, A, figures 1-21; plate 90, A, figures I-15

Shell of about medium size for the genus; wider than long; hinge not equal to
the greatest shell width which is at about the middle, but unusually wide never-
theless. Cardinal extremities obtuse to acute, frequently with pointed ears. Lat-
eral margins gently rounded; anterior margin broadly rounded; anterior com-
missure broadly uniplicate. Surface costellate, 8 to 10 costellae in the space of
5 mm. at the front margin; costellae narrowly rounded and somewhat elevated
with interspaces about equal to the width of the costellae; costellae marked by
innumerable small pores or exopunctae with elevated rims.

Pedicle valve moderately convex in outline with the greatest curvature located
in the posterior third; umbonal region gently convex; beak erect; sulcus origi-
nating near the middle, poorly defined and very shallow. Flanks slightly convex
and the slopes to the cardinal extremities and lateral margins gentle. Interarea
long, nearly procline along the cardinal margin but curving to an apsacline posi-
tion near the beak.

Brachial valve fairly strongly convex in lateral profile, with the maximum
curvature near the middle; strongly convex in anterior profile but with the shell
near the margins slightly flattened. Sulcus originating on the umbo and extend-
ing beyond the middle of the valve as a shallow and narrow depression disap-
pearing near the front. Fold visible only as a wave in the anterior commissure
toward the brachial valve. Median portion of valve swollen and with steep
slopes to the cardinal extremities but more gentle slopes to the anterolateral and
anterior margins.

Pedicle interior with small teeth having deep fossettes. Muscle field large but

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 471

variable, strongly elevated at its front margin. Brachial interior typical for the
genus and family.

Measurements in mm.—

Brachial Hinge i
Length length Midwidth width Thickness

POM YOR Cochise ceri ceec est c ke es 15.2 15.5 18.9 16.5 11.6
Paratype (pedicle valve 110662a).. 20.7 ? 25.3 23.0 6.1
$ GRT7OSTH) ich fei ovideeie sis}. 6 11.3 11.7 15.1 13.8 7.7
a (brachial valve 110669b). ? 20.1 25.1 22.5 6.3

Types.—Holotype: 117037c; figured paratypes: 110662a, 110669b, 117037a-f,
h-j; unfigured paratypes: 110662b,c, 110669a,c-i, 117037g; figured specimen:
110063.

Horizon and locality.—Bromide formation (Mountain Lake member) in Okla-
homa: On Oklahoma Highway 99, zone 36, SW4NW4SW3 sec. 12, T. 1 N.,
R. 6 E., 3 miles south of Fittstown, Pontotoc County ; Decker’s zone 5, sec. 14a,
about 2 miles southeast of McLish Ranch, near Bromide, Johnston County ;
Mimella-bryozoan bed, 2,300 feet south and 2,000 feet west of the northeast cor-
ner sec. 36, T. 1 S., R. 7 E., Johnston County; Decker’s bed 16, on West Branch
of Sycamore Creek, sec. 22 and 27, T. 3 S., R. 4 E., Johnston County; top of
bed 13, old road on hill northwest of old Galbraith Hotel, sec. 32, T. 1 S., R.8 E.,
Johnston County; Rock Crossing of Hickory Creek, approximately center sec.
35, [.5 S., R. 1 E., Criner Hills, Carter County ; along creek 14 miles west and
3 mile south of Nebo, SE# sec. 27, R. 2 S., T. 3 E., Murray County; road cut
on Oklahoma Highway 18, 1.8 miles south of Sulphur, Murray County ; 30 feet
above the Bromide sand in Spring Creek section, sec. 17, T. 2 S., R. 1 W.,
Murray County; bed 17, 266 feet below the top, sec. 22, T. 2 S., R. 3 E.,, 14
miles west of Nebo, Murray County; Mimella zone, Baptist Grounds on Falls
Creek, SWAiNW4iSWS3 sec. 33, T. 1 S., R. 2 E., Murray County; bed 22, road
cut center N4 sec. 11, T. 2 S., R. 3 E., Murray County.

Discussion.—This species is fairly common in the Mountain Lake member of
the Bromide formation at a few localities. It is characterized by a moderately
transverse form and a wide hinge which produces in many instances small ears
or prominent cardinal extremities. The species as identified herein is variable
and like other members of the genus includes narrow as well as wide forms. The
wide-hinged forms are not like any species known from the Appalachian Valley
region. They are also unlike any other Oklahoma species. The narrow forms
which resemble M. subquadrata in outline and profile are more finely costellate.

MIMELLA GILBERTI Cooper, new species
Plate 128, A, figures 1-5

Shell of about medium size for the genus, wider than long, hinge narrower
than the maximum shell width which is located anterior to the middle; sides
oblique, anterolateral extremities narrowly rounded; anterior margin broadly
rounded ; anterior commissure fairly strongly uniplicate. Surface finely costate,
about 46 costae along the front margin.

472 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve unevenly convex in lateral profile, the maximum convexity just
anterior to the umbo and the anterior two-thirds flattened; anterior profile
broadly but gently convex. Umbonal region gently swollen; sulcus broad and
shallow, originating at about the middle and deepening to the anterior margin;
flanks bounding sulcus somewhat flattened. Posterolateral extremities deflected
toward the brachial valve and steep. Interarea long and steeply apsacline.

Brachial valve fairly evenly and strongly convex in lateral profile; anterior
profile strongly domed; umbonal and median region swollen, the swelling con-
tinuing to the anterior margin to form an ill-defined fold; sides gently convex
and with steep slopes to the margins.

Measurements in mm.—Holotype, length 14.3, brachial length 14.1, midwidth
17.0, hinge width 11.8, thickness 10.5.

Types.—Holotype: 123288a; unfigured paratype: 123288b.

Horizon and locality.—Ellett formation (40 to 100 feet above the Knox dolo-
mite) in Virginia: On the west side of the road, 2 miles south of Lusters Gate,
Blacksburg (15’) Quadrangle.

Discussion.—This species is characterized by its fairly large size for such a
stratigraphically low Mimella. It is suggestive of M. nuclea but is a much larger
species with a much more promiment fold and sulcus. M. nuclea has only a slight
development of these features. This is true also of M. vulgaris which approaches
the Virginia species in size. The latter is also different in outline from the Vir-
ginia species. M. valcourensis and M. transversus approach M. gilbertt in size
but are much more finely ornamented.

MIMELLA GLOBOSA (Willard)
Plate 37, A, figures 1-4; plate 88, A, figures 1-30; plate 89, A, figures 1-14
Pionodema globosa Wittarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 274,
pl. 2, fig. 5, 1928.
Hebertella melonica WitLard, ibid., p. 263, pl. 1, figs. 8, 9, 1928.
Mimella superba Butts, Virginia Geol. Surv. Bull. 52, p. 93, pl. 90, figs. 33-36, 1942.

Shell large for the genus, wider than long with the greatest width at about
the middle; hinge narrow; cardinal extremities obtuse. Sides and anterolateral
extremities broadly rounded; anterior margin nearly straight; anterior commis-
sure rectimarginate to faintly uniplicate. Costellae fine, about 10 to 13 in 5 mm.
at the front margin of a large adult.

Pedicle valve moderately convex in lateral profile with the maximum con-
vexity in the median region; anterior profile gently and broadly convex; umbo
swollen ; median region and anterior half flattened to faintly sulcate ; lateral areas
gently convex; posterolateral slopes long, moderately steep. Interarea mod-
erately long, apsacline: Muscle field heart shaped, deeply impressed, and with
a thickened anterior rim; adductor track wide; pallial impressions commonly
exquisitely preserved.

Brachial valve strongly convex in lateral profile and with the greatest con-
vexity slightly posterior to the middle; anterior profile strongly convex with
the median region somewhat narrowly rounded; umbo swollen, sulcus narrow,

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 473

shallow, extending from umbo to anterior margin; flanks bounding sulcus swol-
len ; lateral and posterolateral slopes long and steep. Notothyrial cavity of mod-
erate size; brachiophore plates somewhat reclining ; median ridge short; pallial
marks fairly well impressed.

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
MEINE Fetes eis shai otis isd Shaw blo'dig ace 18.8 18.7 21.4 15.2 II.0
Hypotype: .(1ty7oagoa)»). ra) dite. . 2. .aak 25.5 24.3 30.4 24.4 15.5
rh CPEOBSGD YE Rain scabs says: Fesran 25 22.9 21.5 24.9 18.8 57,3
MY CHRO NP osetia ou oak 18.2 18.2 20.0 15.6 10.9
a CUERO Senne cs See dae ea 19.0 18.6 23.5 21.0 12.1

Holotype (M. melonica M.C.Z. 8596).. 25.4 25.7 29.9 21.0 15.5

Types.—Holotype: M.C.Z. 8609; figured hypotypes: 110680, 110686a,b,
I10713a, 110715, 110718, 110752, 117038b, 117040c,d,f,i, 117041a,b, 117042b;
unfigured hypotypes: 117038a, 117040a. Holotype Mimella melonica (Willard) :
M.C.Z. 8596; holotype M. superba Butts: U.S.N.M. 98210.

Horizon and locality —Benholt formation in Virginia: West slope of the hill
% mile east of Cedar Point School, Hilton (T.V.A. 197-NW) Quadrangle;
south side of Mount Hagan School, Hilton (T.V.A. 197-NW) Quadrangle;
roadside 4 mile southwest of New Bethel Church, Hilton (T.V.A. 197-NW)
Quadrangle; $ mile northeast of Speers Ferry, Clinchport (T.V.A. 188-NW)
Quadrangle; Fugates Hill, 2 miles N. 45° W. of Mendota, Bristol (30’) Quad-
rangle; Lake View Church on Virginia Highway 71, Russell County; Virginia
State Highway 80, $ mile south of Rockdell, Elk Garden (T.V.A. 212-NW)
Quadrangle; on the road to Hansonville, 4 miles northeast of Gate City, Gate
City (T.V.A. 188-NE) Quadrangle.

Benbolt formation Tennessee: 0.1 to 0.2 mile north of the road 1.1 miles north-
east of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

Ridley formation in Georgia: On U. S. Highway 27, just northwest of Chicka-
mauga Creek, Kensington (T.V.A. 106-SE) Quadrangle.

Dryden formation in Tennessee: Lone Mountain to Tazewell road, 14 miles
northeast of Lone Mountain, Tazewell (T.V.A. 154-NE) Quadrangle; hillside
south of Dutch, Dutch Valley (T.V.A. 154-SE) Quadrangle; 2 miles northeast
of Heiskell, Powell Station (T.V.A. 137-SE) Quadrangle; Sycamore Creek,
northwest corner Maynardville (T.V.A. 145-SE) Quadrangle; south side of
the road 1 mile northeast of the watergap south of Bray, Morristown (30’)
Quadrangle.

Dryden formation (Benbolt part) in Virginia: Several localities at Rye Cove,
Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—This species is characterized by its large size, actually approach-
ing that of M. imperator but never equalling it. Mimella globosa is further
featured by its nearly rectimarginate anterior commissure. The commissure
when folded has a broad and gentle wave in the direction of the brachial valve.
This character is like that of the Chazyan Mimellas, but they are generally with
stronger ornamentation than any of the Benbolt forms. The brachial valve of

474 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

M. globosa is often gently sulcate in the posterior half, but the sulcus disappears
before the anterior margin is reached. This is unlike M. imperator which has a
stronger and more prominent sulcus.

The large size of M. globosa restricts its comparison to a few species only. It
differs from M. biconvexa in its more quadrate form and less inflated pedicle
valve. It differs from M. sulcata in its lack of brachial folding and less inflated
pedicle valve.

The species as here conceived includes a number of specimens that seem
clearly to be obese forms that thickened and widened but did not extend the
hinge normally. Some of these occur with more normal members of the popula-
tion, but one locality near New Bethel Church, Hilton (T.V.A. 197-NW) Quad-
rangle, produce a majority of obese forms. The ornamentation of the thickened
specimens is like that of the normal shells. For these reasons the specimens are,
referred to M. globosa.

It is important to state why the writer as first reviser of these species has
used the specific name M. globosa which has page priority and is based on an
adult specimen with pedicle interior. The species Pionodema globosa Willard,
which proved not to belong to the genus to which it was originally assigned, was
selected by Cooper (1930) as the type of the genus Mimella. It will there-
fore cause little confusion to place H. melonica as a synonym of M. globosa rather
than the other way around. Mimella superba of Butts is also placed in synonymy
with M. globosa. The type specimen of that species externally is like M. melonica
but is somewhat more strongly ribbed. It is not, however, more strongly ribbed
than variants of the population which often lived together.

MIMELLA GLOBULARIS Cooper, new species
Plate 87, E, figures 25-37

Shell of about medium size for the genus, wider than long; subrectangular
in outline; strongly biconvex with the brachial valve having a slightly greater
depth than the pedicle one. Anterior commissure broadly uniplicate ; sides some-
what narrowly rounded. Hinge narrower than the greatest shell width; cardinal
extremities obtusely angular. Costellate; costellae subequal in size, crowded
and separated by striae of less width than the costellae. About 17 costellae in
the space of 5 mm. at the front.

Pedicle valve moderately convex in lateral profile with the greatest convexity
located in the posterior half, the anterior half somewhat flattened. Anterior pro-
file broadly convex. Sulcus nearly obsolete, the only trace shown is a broad
flattening in the anteromedian third of the valve. Posterolateral slopes very
steep but becoming more gentle anteriorly. Anterolateral and anterior slopes
gentle. Beak erect and prominent, only slightly incurved; interarea long,
apsacline.

Brachial valve strongly convex in lateral profile; broadly convex in anterior
profile. Umbo marked by a shallow and narrow depression that extends from
the beak nearly to the middle of the valve. Fold obsolete, but a broad wave of

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 475

the anterior margin in a brachial direction serves as a fold. Median area swollen,
slopes in all directions from median area steep, but the lateral and posterolateral
slopes are the steepest.

Pedicle interior with subpentagonal muscle area having long, narrow diduc-
tor scars and a broad adductor field. Median ridge of brachial valve extending
about to middle. Notothyrial cavity deep, brachiophore supports strong.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve)........... 13.3 ? 14.5 II.4 4.1
Paratype ( “ “ —110687g)... 11.4 ? 12.8 10.7 4.5
ie (brachial valve 110687b).. ? 13.0 274 12.9 6.0
é (Chee, “ae TYOOGTINiE a, Une 12.0 14.5 11.8 5.6
fy 6 Sein ett at LOUG7a)) eon ten 11.8 14.6 11.9 5.3

Types.—Holotype: 110687d; figured paratypes: 110687a,c,f,g,1; unfigured
paratypes: 110687b,e,h.

Horizon and locality—Yellow Branch member of Poteet formation in Vir-
ginia: On the road beside Yellow Branch (Creek) 5 miles southeast of Rose
Hill, Rose Hill (T.V.A. 161-NE) Quadrangle.

Ridley formation in Tennessee: 7 miles southwest of Pikeville, Sequatchie
Valley, Bledsoe County.

Discussion.—This is a rare species best known from near Rose Hill where it
is common in a silicified state in a calcarenite in the lower part of the section.
The species is characterized by its medium size, rotund and swollen form, and
fine ornamentation. Its outline is similar to that of M/. intermedia, but its valves,
particularly the pedicle valve, are much more swollen and its ornamentation more
delicate. It is suggestive of M. similis and M. costellata in its fine ornamenta-
tion but differs from both in the shape and more swollen valves.

MIMELLA IMPERATOR (Billings)
Plate 85, F, figures 40-45

Orthis imperator BiLL1Ncs, Canadian Nat. Geol., vol. 4, p. 435, figs. 11-13, 1859; Geol. Canada,
p. 129, fig. 55, 1863.—Lrstey, Geol. Surv. Pennsylvania, Rep. P 4, p. 518, figs., 1880.
Hebertella imperator (Billings) Hatt and CrarxKe, Pal. New York, vol. 8, pt. 1, p. 222,
1892.—Raymonp, Ann. Carnegie Mus., vol. 7, p. 243, pl. 36, figs. 6, 7, 1911—WHILSON,

Trans. Roy. Soc. Canada, ser. 3, vol. 26, sec. 4, p. 381, pl. 2, figs. 1, 2, 1932.

Types.—Syntypes: G.S.C. 1036, a; figured hypotypes: Carnegie Mus. 5447,
5448.

Horizon and locality—Aylmer formation (Rockcliffe member) in Ontario,
Canada: 44 miles west of Ottawa; Hawkesbury. Same formation in Quebec,
Canada: At Aylmer.

Discussion.—This is the largest of the known species of the genus. This is an
anomalous fact because the species shows primitive features in its fairly strong
brachial sulcus and faintly medially folded pedicle valve. Well-preserved but
partially exfoliated specimens (G.S.C. 1036, a) in the Geological Museum of

476 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Canada show the characteristic Mimella pedicle muscle scars and some details
of the pallial marks. In the pedicle valve the ovarian impressions are small but
prominent and marked by oblique wavy lines. The pallial trunks are separated
by shallow depressions. In the brachial valve the main trunks are given off from
the anterior ends of the adductors and branch anteriorly.

MIMELLA INTERMEDIA Cooper, new species
Plate 90, B, figures 16-20; plate o1, F, figure 25; plate o1, F, figures 26-28;
plate 91,1, figures 37-39

About medium in size for the genus, slightly wider than long with the great-
est width at or slightly anterior to the middle ; cardinal extremities obtusely angu-
lar; sides slightly sinuate just anterior to the cardinal extremity ; anterolateral
extremities narrowly rounded; anterior margin truncated to emarginate; an-
terior commissure rectimarginate. Costellae numbering 9 to II in 5 mm. at the
anterior margin, separated by striae narrower than the costellae.

Pedicle valve gently convex in lateral profile, the greatest convexity in the
umbonal region and the anterior half or more somewhat flattened. Anterior pro-
file broadly and gently convex but with short, steep lateral slopes. Beak some-
what elongated ; umbo swollen ; median half occupied by a narrow, shallow sulcus
which disappears at the margin. Flanks bounding sulcus gently swollen; pos-
terolateral slopes short and steep. Interarea approximately procline, slightly
curved but with the beak abruptly curved. Interior with large, heart-shaped
muscle area; adductor track wide and anteriorly elevated; pallial marks not
preserved.

Brachial valve strongly convex, with the greatest curvature in the umbonal
region; anterior half moderately convex; anterior profile strongly convex with
long and steep lateral slopes; umbo sulcate; umbo strongly swollen; median part
of anterior and middle flattened to faintly sulcate; flanks bounding median re-
gion moderately swollen; posterolateral slopes steep; cardinal extremities de-
flected to form small ears. Interior with thin cardinal process; notothyrial cavity
moderately deep, median ridge narrow, not reaching to the middle.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holoty pesos sh oBRiie oy aioe dla 15.2 15.2 17.6 14.8 12.0
Paratype (1170449) oie 2s. esis 16.2 16.0 17.4 13.5 rie hi

Types.—Holotype: 117044b; figured paratypes: 110703a,b, 117043, 117998;
unfigured paratype: 1170442.

Horizon and locality—Whistle Creek formation in Virginia: On Whistle
Creek, 14 miles northwest of Lexington; on U. S. Highway 60 about 100 yards
southeast of Whistle Creek, 2 miles northwest of Lexington, Lexington (15’)
Quadrangle; 35 miles southwest of Bolton, Bristol (30’) Quadrangle.

Elway formation in Tennessee: Along the road over Marble Bluff just north
of summit about 8 miles west-northwest of Loudon, Loudon (30’) Quadrangle ;

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 477

on U. S. Highway 25W, 4.7 miles south of Clinton, Powell Station (T.V.A.
137-SE) Quadrangle.

Discussion—Mimella intermedia is characterized by a subquadrate form,
nearly rectimarginate anterior commissure, fairly strongly convex valves and
fairly strong ornamentation. The species resembles M. subquadrata but differs
in having somewhat finer costellae, more erect and elongate pedicle beak, some-
what narrower hinge, and less prominently waved anterior commissure.

This species might be confused with some of the stratigraphically younger nar-
row forms of M. globosa. The latter are generally thicker shelled and give evi-
dence of obesity rather than normal specific characters. These obese forms also
generally have much more swollen valves than the normal Elway and Whistle
Creek species.

MIMELLA LATICARDINIA Cooper, new species
Plate 90, C, figures 21-34

Shell of about medium size for the genus, slightly wider than long; greatest
shell width at about the middle; sides broadly rounded, anterior margin broadly
rounded. Anterior commissure gently uniplicate. Surface costellate, with 9
costellae occupying a space of 5 mm. at the front margin of a full-grown speci-
men. Costellae appear in 3 or 4 generations.

Pedicle valve most convex in the posterior third when viewed in lateral profile ;
posterior third moderately convex but anterior two-thirds flattened. Umbonal
region gently convex with erect beak; sulcus originating 10 to 12 mm. anterior
to the beak, poorly defined in medium-sized shells, more strongly defined in fully
grown specimens but in any case seldom deep. Posterior half slightly swollen,
the fullness continued on each side of the median depression to the anterior mar-
gin; lateral slopes moderately steep. Interarea long, slightly curved, apsacline.

Brachial valve with the maximum convexity at about the middle in lateral pro-
file. Anterior profile strongly convex in the middle but lateral slopes only moder-
ately steep. Umbo marked by a short (6 or 7 mm.), narrow sulcus changing
anteriorly into a barely perceptible fold. Median region and posterior swollen,
with steep slopes to the cardinal extremities and lateral margins. Anterior slope
gentle. Interarea short, curved, apsacline.

Pedicle interior with small teeth having deep fossettes; dental plates strong,
bowed outward near the junction with the floor of the valve and continued an-
teriorly along the margins of the muscle field as a low ridge. Adductor track
long and wide at the front; diductor impressions narrower than the adductor
track ; pallial marks not strongly impressed.

Brachial valve with short brachiophores, moderately strong median ridge, and
brachiophore supports resting on the floor of the valve; cardinal process slender.

Measurements in mm—
Brachial Hinge

Length length Width width Thickness
Holotype. ....<«s0.2 ba aes3e.2 «A 19.4 18.0 21.8 18.0 12.7
Paratype (it0700b)))... - o: . 14.8 14.4 17.0 13.3 9.8

a RT TOZOOD) ic. 02 585 oe 17.5 16.6 20.6 16.4 11.0

478 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 1107094 ; figured paratypes: 110700a-d, 110702a, 110706b;
unfigured paratypes: 110700e, 110702b-f, 110706a, 110709b.

Horizon and locality—Lincolnshire formation in Tennessee: 4 mile northwest
of Eidson Post Office, Kyles Ford (T.V.A. 170-SE) Quadrangle; Evans Ferry
section, northeast of Indian Creek on U. S. Highway 25E, Howard Quarter
(T.V.A. 162-NW) Quadrangle; on U. S. Highway 25E, Thorn Hill section,
shale unit south of first bridge north of Thorn Hill Post Office, Avondale (T.V.A.
162-SW) Quadrangle.

Lincolnshire formation in Virginia: In Marcem Quarry, 2 miles west of Gate
City, Gate City (T.V.A. 188-NE) Quadrangle; Virginia Highway 19, 0.3 mile
east-southeast of Hansonville, Hansonville (T.V.A. 205-SW) Quadrangle; at
spring + mile east of junction of Virginia Highways 608 and 652, 6 miles south-
east of Staunton, Augusta County; north side of Moccasin Creek, 0.2 mile west
of New Bethel Church, Hilton (T.V.A. 197-NW) Quadrangle.

Murat formation (calcarenite facies of Lincolnshire) in Virginia: 2 miles
northwest of Lexington, Lexington (15’) Quadrangle.

Discussion—This is not a common species as far as the author’s collecting
experience in the Appalachians indicates. It was common in the shaly beds of
the Lincolnshire formation north of Eidson, but that place is now fairly well ex-
hausted. The species, as usual with Mimella, is somewhat variable in all its
features. Generally it is rectangular in outline with a fairly wide hinge, mod-
erately inflated valves, usually moderately uniplicate anterior commissure, promi-
nent beak, and moderately strong costellae.

This is one of the largest of the Mimella species below the Benbolt and, inas-
much as it occurs in some shaly beds, it may be confused with M. globosa. It,
however, seldom attains the large size of that species and usually has more pro-
nounced anterior folding and finer costellae than the Benbolt form. The Lin-
colnshire species differs from M. intermedia in its more transverse outline. It
differs from M. twmida of the Hogskin member in its generally smaller size, finer
ornamentation, and more quadrate form.

Specimens from the Lincolnshire formation at Marcem Quarry west of Gate
City have been placed here, although they are larger and with somewhat more
inflated pedicle valve than M. laticardinia, but medium-sized specimens from
the same place are very close to the Eidson forms.

MIMELLA LATISTRIATA (Wilson)
Hebertella latistriata Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 26, sec. 4, p. 380, pl. 2,

figs. 4-7, 1932.

Types.—Holotype: G.S.C. 6524; paratypes: G.S.C. 6524a, 6525.
Horizon and locality.—Aylmer formation in Ontario, Canada: From the shaft
at the west end of Barnhart Island southwest of Cornwall.

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 479

MIMELLA MINGANENSIS Twenhofel and Whiting

Orthis piger BILLINGs, (part), Canadian Nat., vol. 4, pp. 442-443, 1850.
Mimella ? minganensis TWENHOFEL and WHITING, Geol. Soc. Amer. Special Pap. 11, p. 47,
pl. 7, figs. 10-12, 1938.

Horizon and locality—Mingan formation (zone 10) in Mingan group:
Quarry and Eskimo Islands.

MIMELLA NUCLEA (Butts)
Plate 85, B, figures 13-26
Orthis nucleus Butts, Alabama Geol. Surv., Special Rep. 14, pl. 22, fig. 6, 1926.

Small, subquadrate in outline, valves of unequal depth, the brachial valve hav-
ing a slightly greater depth than the pedicle one. Cardinal extremities rounded,
obtuse ; lateral margins gently rounded, anterior margin broadly rounded to sub-
truncate ; anterolateral extremities narrowly rounded. Surface multicostate, most
of the costae extending directly from the beak to the anterior margin but a few
may be intercalated ; from 7 to 9 costae occupy 5 mm. at the front margin depend-
ing on the size.

Pedicle valve semipyramidal, unequally convex in lateral profile with the great-
est curvature in the posterior third ; front two-thirds flattened. Umbonal region
narrowly convex with moderately steep slopes to the cardinal extremities. Me-
dian region with poorly defined fold in the young, the fold extending to about
the middle in adults but the front part of the valve anterior to the fold flattened
or slightly sulcate. Flanks gently convex. Palintrope long, producing a pointed
beak which is slightly incurved ; interarea strongly apsacline.

Brachial valve moderately convex in lateral profile, fairly strongly convex in
anterior profile; umbo marked by a narrow and shallow sulcus that extends an-
teriorly to the front margin where it occupies a third or less of the width. Slopes
from umbo and flanks steep ; flanks somewhat narrowly rounded ; interarea fairly
long for the genus, apsacline in position.

Pedicle interior with large muscle area which is slightly longer than wide;
diductor scars elongate, adductor track elevated at the front end; adjustor im-
pressions long and slender. Brachial interior with median ridge reaching about
to the middle of the valve ; cardinal process long and slender ; notothyrial cavity
wide, supporting plates of brachiophores thick, wide, and shallow.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Bio ety pe ais. 8 6 s.5.c ale octets 9.4 ? 9.7 ? ?
Hypotype (110773d)......... 9.5 7.0 10.4 9.0 6.8
re CUTO77 IO ecw le. os 11.3 10.8 13.9 10.7 6.6-+-+
é ORIG 73a )e0G. UIE 12.4 11.4 14.3 11.0 8.7+

Types.——Holotype: 71487; figured hypotypes: 110773a-d.
Horizon and locality—Lenoir formation in Alabama: 2 miles west-southwest
of Pratts Ferry, southwest of Montevallo.

480 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Lenoir formation (lower 100 feet) in Tennessee: 14 miles south of Phila-
delphia, Philadelphia (T.V.A. 131-NW) Quadrangle; # mile northeast of
Friendsville ; south side of cemetery at Quaker Church, northwest corner Friends-
ville; Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—This species hitherto has been referred to in literature on the
Southern Appalachians as Raymond’s species Hebertella vulgaris, but several
significant differences may be noted. The Champlain Valley species has a wider
hinge and the cardinal extremities are much more prominent than those of the
Tennessee specimens. The southern species is much less regular in outline and
has a longer interarea, a longer and more curved beak. The costae in both
species are very regular and direct. In both, intercalations take place only at the
umbo and the number of costae is about the same. Nevertheless, those of
M. nuclea are separated by somewhat wider intercostal spaces which give the
species the appearance of being somewhat coarser ribbed than it is.

Mimella nucleoidea resembles the southern species, but it has different ribbing
and had both valves more convex than those of M. nuclea. The latter is a fairly
common species in the calcarenites associated with the Lenoir formation. It is
also found in shales particularly around Philadelphia, Tenn. It occurs in cal-
carenites from Alabama to southern Virginia.

MIMELLA NUCLEOIDEA Cooper, new species
Plate 87, B, figures 6-15

Hebertella vulgaris RayMonD (part), Ann. Carnegie Mus., vol. 7, No. 2, p. 242, text figs. 15,
17, 18, pl. 36, figs. 2, 4, 5?, I91T.

Small, wider than long, subrectangular in outline, sides gently rounded and
anterior margin broadly rounded; greatest width at or anterior to the middle;
anterior commissure rectimarginate. Hinge narrower than the shell width; cardi-
nal extremities obtuse, not prominent. Multicostellate, about 9 costellae in 5 mm.
at the front margin. Costellae narrowly rounded, separated by spaces having a
width about equal to the width of the costellae. Costellae increasing by intercala-
tion and bifurcation, particularly at about midlength of the valve; anterior inter-
calations scattered and usually few.

Pedicle valve moderately convex in lateral profile, most convex in the posterior
half, somewhat flattened anteriorly ; broadly and gently convex in anterior pro-
file; posterior and umbonal region moderately swollen, anterior region broadly
flattened ; lateral areas gently rounded but with short, steep slopes to the cardinal
extremities. Beak long, moderately incurved ; interarea long, strongly apsacline.

Brachial valve in lateral profile evenly and moderately convex with the great-
est convexity at about the midlength; anterior profile strongly and broadly
rounded with short, steep lateral slopes; umbonal region swollen; beak strongly
incurved and overhanging the pedicle interarea; umbo depressed medianly by a
shallow sulcus that widens slightly anteriorly and extends nearly to the anterior
margin; sulcus never prominent and often disappearing at the front margin.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 481

Median region strongly swollen and with steep but short slopes to the lateral
margins and cardinal extremities.

Interior of pedicle valve with well-developed dental plates and strongly im-
pressed muscle field. Diductor scars long and narrow; adductor ridge promi-
nent, elevated, and somewhat elongated; adductor scars crescentic. Brachial
valve with short, elevated median ridge; notothyrial cavity deep; brachiophores
short, supporting plates thick, moderately elevated anteriorly ; cardinal process
a simple ridge.

Measurements in mm.—

Brachial Width Hinge

Length length width Thickness
TOLOEY DE te sist sie ceteris: 11.6 10.4 14.2 10.6 8.9
Paratype (110804a) ......... 11.6-+ 10.7 13:3 10.8 8.2

Types.—Holotype: 110786; figured paratypes: 110804a, 110797a,b; unfigured
paratypes: 110804b-e, 110797c.

Horizon and locality—Crown Point formation in New York: Sloop Bay,
Valcour Island, Lake Champlain, Plattsburg (15’) Quadrangle.

Discussion.—This species is characterized by its narrow hinge, strongly convex
valves and numerously intercalated costellae. It differs from M. vulgaris Ray-
mond in its convex valves, numerous costellae, narrow hinge, and less strongly
apsacline interarea. It suggests M. nuclea but is more convex, has a less
apsacline interarea, somewhat narrower hinge, and more numerous costellae.

MIMELLA PIGER (Billings)
Plate 99, D, figures 20-23
Orthis piger Brttincs (in part), Canadian Nat., vol. 4, pp. 442, 443, 1859.

Plectorthis ? piger (Billings) TwENHOFEL and Wuittnc, Geol. Soc. Amer. Special Pap. 11,
p. 48, pl. 7, figs. 7-9, 1938.

Cooper examined the specimen figured by Twenhofel and Whiting and identi-
fied it as a Mimella rather than a Plectorthis. The ribbing, profile, and length
of interarea of the pedicle valve are wrong for Plectorthis. It does not seem to
be the same as “Plectorthis” exfoliata (Raymond).

Type—Hypotype: Y.P.M. 15823.

Horizon and locality—Mingan formation in Mingan group: On Parroquet
and Eskimo Islands.

MIMELLA SIMILIS Cooper, new species
Plate o1, B, figures 8-12; plate 91, C, figures 13-18; plate 92, D, figures 23-28

Shell of about medium size for the genus, wider than long; subrectangular in
outline; sides moderately rounded; anterior margin broadly rounded; anterior
commissure nearly rectimarginate to gently uniplicate. Hinge narrower than the
greatest shell width which is anterior to the middle; cardinal extremities form-
ing a small obtuse angle. Multicostellate, costellae narrowly rounded and ele-
vated, closely crowded, 3 in the space of 1 mm. at the front margin.

482 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve unevenly convex in lateral profile with the posterior half mod-
erately convex and the anterior half depressed toward the brachial valve. An-
terior profile broadly and gently convex, the median region forming the crest of
the arch. Beak erect and only slightly incurved ; umbo somewhat narrowly swol-
len ; posteromedian region gently swollen ; anteromedian area depressed to form a
shallow sulcus; flanks bounding sulcus slightly swollen ; lateral slopes gentle but
steepening toward the cardinal extremities. Interarea moderately long, nearly
catacline.

Brachial valve fairly evenly and moderately convex in lateral profile; anterior
profile strongly convex with long and steep lateral slopes. Umbonal region nar-
rowly convex and merging into the swollen median region. Fold not pronounced,
defined as a broad swelling of the anterior ; lateral slopes long ; cardinal extremi-
ties prominent. Interarea moderately long, curved over the pedicle interarea.

Interior of pedicle valve with strongly elevated adductor track and long, nar-
row diductor troughs.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype !:. scistt ees 2h. . 12.9 13.0 16.0 13.0 7.8
Paratype (117046b).......... 16.0 ? 19.6 15.3 ry
+ (TT7OASA Ne a's dilcd: 14.3 13.5 17.0 127 8.6

Types.—Holotype: 117046a; figured paratypes: 110737, 117046b, 1170474,
117048a; unfigured paratypes: 117047b,c.

Horizon and locahity—Lincolnshire formation (Hogskin member) in Tennes-
see: 0.2 mile northwest up farm lane, 4 mile southwest of Fleanor Mill, Powell
Station (T.V.A. 137-SE) Quadrangle; 500 feet below ‘‘Holston” marble, Lee
Valley Post Office, Lee Valley (T.V.A. 171-NW) Quadrangle; 4 mile south-
west of Beeler Cemetery, Hogskin Valley, Powder Springs (T.V.A. 154-SW)
Quadrangle; 2 miles southwest of Hall Crossroad, northwest quarter center
subquad., Fountain City (T.V.A. 146-SW) Quadrangle; Evans Ferry, Howard
Quarter (T.V.A. 162-NW) Quadrangle; 1 mile southeast of Washburn, Dutch
Valley (T.V.A. 154-SE) Quadrangle; 2.65 miles southwest of Mount Eager
Church, Hogskin Valley, Powder Springs (T.V.A. 154-SW) Quadrangle; Red
Hill, 44 miles southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quad-
rangle; 3 and 33 miles west-southwest of Thorn Hill, Avondale (T.V.A.
162-SW) Quadrangle; stream and road crossing on U. S. Highway 25E, 4 mile
north of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle; Raccoon Valley,
5 miles south of Clinton, Powell Station (T.V.A. 137-SE) Quadrangle.

Discussion.—This is a species of moderate size suggesting small examples of
Mimella globosa. Confusion with the latter species is easy because the Hogskin
shale has been called Ottosee, parts of which are the source yielding M. globosa.
The two species may be distinguished by the smaller size of the Hogskin form
which generally has prominent and slightly obtuse cardinal extremities, a some-
what more convex and deeper pedicle valve, more strongly apsacline interarea.
This species differs from M. twmida in its much smaller size and finer costellae.

PART, j\I CHAZYAN AND RELATED BRACHIOPODS—COOPER 483

MIMELLA SUBQUADRATA Cooper, new species
Plate 92, B, figures 5-9

Moderately large for the genus, width slightly greater than the length ; brachial
valve somewhat deeper than the pedicle valve; sides nearly straight ; cardinal
extremities nearly a right angle, anterolateral extremities narrowly rounded;
anterior margin gently emarginate; anterior commissure gently and broadly
uniplicate. Surface marked by 9 or 10 narrowly rounded costellae in 5 mm. at
the anterior margin; striae narrower than the width of the costellae at the
anterior margin.

Pedicle valve in lateral profile unevenly convex, the posterior half flatly con-
vex but the anterior half sloping moderately toward the brachial valve; anterior
profile broadly and gently convex ; umbonal region gently convex ; median region
flattened and anterior third depressed into a broad and shallow sulcus. Postero-
lateral slopes short and steep. Interarea nearly flat, perceptibly apsacline; beak
slightly curved.

Brachial valve fairly strongly and evenly convex in lateral profile with the
maximum convexity at about the middle; anterior profile steeply domed and with
long, steep lateral slopes ; umbonal and median regions strongly swollen ; antero-
median region somewhat flattened ; umbonal region swollen; beak strongly over-
hanging pedicle interarea ; umbo with a short, barely perceptible sulcus not visible
anteriorly ; cardinal extremities prominent as small ears.

Measurements in mm.—Holotype, length 16.7, brachial length 17.5, width 109.3,
hinge width 18.5, thickness 13.4.

Type——Holotype: 117050a; unfigured paratypes: 117049a,b, 117050b,
117051a-c.

Horizon and locality—Bromide formation (Mountain Lake member-lower
Sowerbyites bed) in Oklahoma: 25 to 46 feet above the Bromide sand on Spring
Creek, N43 sec. 17, T. 2S., R. 1 W., Murray County.

Discussion—This species is characterized by a subquadrate outline, strongly
convex brachial valve, nearly catacline interarea, and fairly strong costellae. It
is most like M. intermedia in shape but differs in having a more convex brachial
valve, stronger costellae, and larger size. In the same respects M. subquadrata
differs from narrow forms of M. extensa.

MIMELLA SULCATA Cooper, new species
Plate 87, D, figures 20-24

Large, somewhat transversely elliptical in outline; length about four-fifths the
width; valves subequal in depth; hinge width about equal to the length; lateral
extremities somewhat narrowly rounded; anterior margin nearly straight; an-
terior commissure narrowly uniplicate ; surface costellate, 3 in I mm. at the front
margin.

Pedicle valve moderately convex in lateral profile and with the greatest con-
vexity in the posterior half; anterior profile strongly and broadly convex; umbo-
nal and posterior third to half swollen; sulcus short, deep, narrow, originating at

484 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

about the middle; tongue short and narrowly rounded; lateral slopes steep;
interarea moderately long, apsacline; beak incurved.

Brachial valve moderately convex in lateral profile but with the greatest con-
vexity at the middle; anterior profile slightly more convex and with somewhat
steeper lateral slopes than those of the pedicle valve; umbonal region somewhat
flattened ; median area strongly inflated; anterior region moderately convex but
not forming a pronounced fold, the tongue of the pedicle valve inserted into a
reentrant wave of the brachial commissure.

Measurements in mm.—Holotype, length 20.2, brachial length 18.2, width 26.0,
hinge width 18.9, thickness 14.4.

Type.—Holotype: 117053.

Horizon and locality—Benbolt formation in Virginia: On the north side of
U. S. Highway 19, 13 miles southeast of Hansonville Post Office, Brumley
(T.V.A. 205-SE) Quadrangle.

Discussion.—This is a rare species; only one specimen has been found up to
the present writing. This species suggests M. biconvexa and M. globosa. It
differs from both of them in the somewhat narrow brachial fold of the anterior
commissure and the small, narrow pedicle tongue. Another characteristic feature
separating this species from the two mentioned and from most other Mimellas
is the flattened umbo of the brachial valve.

MIMELLA TRANSVERSA Cooper, new species
Plate 85, D, figures 33-37

Shell of about medium size for the genus, transversely subrectangular in out-
line ; sides broadly rounded; greatest width anterior to the middle; anterolateral
extremities narrowly rounded; anterior margin nearly straight ; anterior commis-
sure broadly and faintly uniplicate. Valves subequal in depth. Surface multi-
costellate, about 8 or 9 costellae in 5 mm. at the anterior margin; costellae nar-
rowly rounded and separated by striae narrower than the width of the costellae.

Pedicle valve unevenly and moderately convex in lateral profile and with the
maximum convexity in the posterior half, anterior half flattened ; anterior profile
broadly subtriangular with long, gently sloping sides and low, rounded apex;
umbonal and median regions swollen ; anteromedian area flattened, posterolateral
slopes long and moderately steep; interarea moderately long, apsacline; beak
erect.

Brachial valve fairly evenly convex in lateral profile with the maximum con-
vexity in the median region; anterior profile strongly and broadly convex with
the top gently flattened but with short, steep lateral slopes ; umbonal and median
regions swollen. Sulcus originating on the umbo, shallow and inconspicuous,
widening moderately anteriorly and bounded by low, narrow swellings; lateral
slopes long and moderately steep. Beak partially overhanging pedicle interarea.

Measurements in mm.—Holotype, length 14.5, brachial length 14.0, width
19.4, hinge width 14.2, thickness 10.1.

Type.—Holotype: 117052.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 485

Horizon and locality—Valcour formation in New York: On Valcour Island,
Lake Champlain, Plattsburg (15’) Quadrangle.

Discussion.—This is a fairly large species characterized by a nearly recti-
marginate anterior commissure, sulcate brachial valve, and numerous costellae.
The species is somewhat more strongly costellate than the Southern Appalachian
species but is more finely costellate than the common New York M. vulgaris. It
is also larger than that species and M. nucleoidea. It suggests M. extensa in
ornamentation but has a much narrower hinge.

MIMELLA TUMIDA Cooper, new species
Plate 80, B, figures 15-23

Shell fairly large for the genus, wider than long; subrectangular in outline;
sides moderately rounded; anterior margin broadly rounded; anterior commis-
sure gently uniplicate ; hinge equal to about two-thirds the width; cardinal ex-
tremities obtusely rounded; greatest width near the middle. Multicostellate,
costellae narrowly rounded, somewhat crowded, often fasciculate on parts of the
shell, about 2 to the millimeter at the front margin of an adult.

Pedicle valve fairly strongly convex in lateral profile with most of the con-
vexity in the posterior half and with the front half somewhat flattened ; anterior
profile fairly strongly convex and forming a dome with fairly steep sides. Um-
bonal region somewhat narrowly swollen; posteromedian region gently swollen
and with long, steep slopes to the cardinal extremities; anterior half somewhat
flattened and in the median region along the margin depressed into a shallow
sulcus. Interarea curved, apsacline ; beak incurved.

Brachial valve in lateral profile fairly strongly convex, the posterior part the
most convex; anterior profile strongly convex and forming an arch highest in
the middle and with long, steep lateral slopes. Umbonal region inflated and
somewhat elevated posterior to the posterior margin; median region swollen;
anterior somewhat flattened. Interarea strongly curved over the pedicle inter-
area; beak prominent.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PIoloty perce. oe elie outs os 21.5 21.0 24.9 16.7 14.8
Paratype (llO730)))) es: ceeialels 13.6 12.9 16.3 13.6 9.2

Types.—Holotype: 110714; figured paratype: 110739.

Horizon and locality—Lincolnshire formation (Hogskin member) in Ten-
nessee: # mile southwest of Washburn, Dutch Valley (T.V.A. 154-SE) Quad-
rangle; Maynardville Pike, 1.7 miles north of Hall Crossroad, Fountain City
(T.V.A. 146-SW) Quadrangle; Evans Ferry, Howard Quarter (T.V.A.
162-NW) Quadrangle; 44 miles west-southwest of Thorn Hill, Avondale
(T.V.A. 162-SW) Quadrangle.

Discussion—This species is like M. globosa and approaches that species in
size, although the biggest specimens of M. tumida are smaller than the largest

486 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ones of M. globosa. In general M. tumida is more strongly costellate than the
general run of M. globosa, but it is suggestive of the more strongly costellate
ones called M. superba by Dr. Butts. However, the pedicle valve of the Hogskin
species is more tumid than that of M. globosa.

MIMELLA ULRICHI Cooper, new species
Plate 87, A, figures 1-5

Shell small for the genus, transversely rectangular in outline; sides rounded;
cardinal extremities obtusely rounded ; anterior margin emarginate medially ; an-
terior commissure gently and broadly sulcate. Multicostellate, costellae narrowly
rounded, closely crowded, increasing by bifurcation, often fasciculate.

Pedicle valve evenly and gently convex in lateral profile; broadly convex in
anterior profile with the median region rounded and long, moderate slopes to the
margins. Umbonal region swollen, the swelling continuing anteriorly but increas-
ingly indistinct to the front margin and thus serving as a poorly defined fold.
Flanks gently convex and sloping moderately to the margins. Interarea curved,
nearly catacline ; beak gently incurved.

Brachial valve having less depth than the pedicle valve, gently but evenly con-
vex in lateral profile. Anterior profile broadly convex but depressed slightly in
the median region and with moderately long and moderately steep lateral slopes.
Umbo sulcate ; sulcus shallow throughout its length, originating at the beak and
extending to the front margin. Flanks bounding sulcus gently swollen; lateral
slopes moderately short. Interarea short, anacline.

Measurements in mm.—Holotype, length 7.9, brachial length 7.2, width 10.7,
hinge width 9.4, thickness 4.8.

Types.—Holotype: 110805.

Horizon and locality—Crown Point formation in New York: At Sloop Bay,
Valcour Island, Lake Champlain, Plattsburg (15’) Quadrangle.

Discussion.—This little species is characterized by its transversely rectangu-
lar outline, strongly sulcate brachial valve, wide hinge, and fine costellae. It
occurs with M. nucleoidea but is readily distinguished by its greater width.

MIMELLA VALCOURENSIS Cooper, new species
Plate 85, C, figures 27-32

Shell of about medium size for the genus; wider than long and with a some-
what rectangular outline; depth of valves subequal; greatest width anterior to
the middle; lateral margins sloping obliquely anteriorly to the narrowly rounded
anterolateral extremities. Anterior margin slightly emarginate; anterior com-
missure broadly and gently uniplicate. Surface multicostellate, costellae broad,
crowded, 8 or 9 in the space of 5 mm. at the anterior margin of the flanks, nar-
rower and more crowded in the midregion.

Pedicle valve having unequal convexity, the most convex part in the posterior
half, the anterior half sloping steeply toward the brachial valve; anterior profile

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 487

moderately convex, somewhat flat topped and with short, steep lateral slopes ;
umbonal region swollen; sulcus shallow and broad, originating about 5 mm.
anterior to the beak; flanks bounding sulcus gently swollen; umbonal slopes
to the cardinal extremities steep. Interarea long, catacline, but with strongly
and narrowly incurved beak.

Brachial valve strongly convex and with the greatest convexity in the pos-
terior half ; anterior half sloping moderately to the pedicle valve ; umbonal region
strongly convex ; beak strongly incurved and overhanging the pedicle interarea ;
median region broadly sulcate, sulcus originating anterior to the umbo, broad
and shallow, poorly defined at the front margin. Lateral slopes short and steep.

Measurements in mm.—Holotype, length 13.8, brachial length 13.3, width 17.2,
hinge width 13.5, thickness 11.3.

Type.—Holotype: 110792.

Horizon and locality—Probably Valcour formation in New York: On Val-
cour Island, Lake Champlain, Plattsburg (15’) Quadrangle.

Discussion.—This species is similar in ornamentation to M. transversa but
differs markedly in having both valves much more tumid and in being much less
transverse. The interarea is longer and the beak narrower than M. transversa,
and the brachial valve has a more strongly arched umbonal region. Mimella
valcourensis is a rare species; only a single specimen is now known.

MIMELLA VIRGINIENSIS Cooper, new species
Plate 37, B, figures 5-7; plate 91, H, figures 35, 36
Mimella sp. Butts, Virginia Geol. Surv. Bull. 52, p. 43, pl. 73, figs. 47-52, 1942.

Shell large, wider than long, with well-rounded sides and gently rounded
anterior margin. Hinge narrow; anterior commissure very gently uniplicate.
Surface multicostellate, costellae numbering 10 to 5 mm. at the front margin.

Pedicle valve fairly evenly and gently convex in lateral profile but with an-
terior somewhat flattened. Anterior profile broadly and moderately convex.
Umbonal and median regions swollen; anterior region gently inflated except for
median quarter which is depressed to form a shallow sulcus. Posterolateral
slopes somewhat inflated but steeply inclined to the cardinal extremities. Inter-
area long, apsacline; beak very gently incurved.

Brachial valve strongly convex in lateral profile and with the maximum con-
vexity at about the middle; anterior profile strongly arched, with steep and long
lateral slopes. Whole median region and umbo strongly swollen. Lateral slopes
long and steep. Interarea short.

Measurements in mm.—Holotype, length 18.5, brachial length 17.2, width 22.6,
hinge width 16.8, thickness 12.9.

Types.—Holotype: 98188a, figured paratype: 110694; unfigured paratypes:
98188b-e.

Horizon and locality.—Whistle Creek formation in Virginia: 14 miles north-
west of Lexington, Lexington (15’) Quadrangle; top of the ridge 1,000 feet

488 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

north of the road on Buffalo Creek, 24 miles west of Murat, Natural Bridge
(15’) Quadrangle.

Discussion.—This species is characterized by its fairly large size and strongly
convex valves. In these respects it is similar to M. biconvexa and M. globosa.
It differs from the former in having a rectimarginate anterior margin, and from
the latter in having a much more strongly convex pedicle valve. This species is
different from all the pre-Benbolt species in the subequal depth of its valves. It
is more finely costellate than 1. tumida and is larger and more convex in both
valves than M. laticardinia.

MIMELLA VULGARIS (Raymond)
Plate 85, A, figures 1-12; plate 92, E, figures 29-33

Hebertella vulgaris RayMonp, Ann, Carnegie Mus., vol. 3, p. 501, 1906; ibid., vol. 7, No. 2,
Pp. 242, text fig. 16, pl. 36, fig. 3, I91T.

Shell of about medium size for the genus, somewhat variable; wider than
long, somewhat rectangular in outline and generally with the hinge only slightly
less than the width ; cardinal extremities usually slightly obtuse. Sides very gently
rounded ; anterior margin broadly rounded; anterior commissure rectimarginate
to faintly uniplicate. Surface costellate, costellae usually narrowly rounded, dis-
tant and numbering 6 to 9 in 5 mm. at the front margin at or near the middle.
Costellae direct from umbo where bifurcation and intercalation takes place.

Pedicle valve unevenly convex in lateral profile, the posterior half gently con-
vex and the anterior half flattened; anterior profile forming a broad triangle
with long, gently sloping sides and broadly rounded apex. Umbonal region some-
what swollen, the swelling continuing to about the middle; anteromedian region
flattened ; lateral slopes short, steepening to the cardinal extremities. Beak gently
curved ; interarea moderately long and strongly apsacline.

Brachial valve moderately convex in lateral profile with maximum convexity
in the umbonal region; anterior profile moderately domed and with steep lateral
slopes; beak fairly strongly incurved; umbo and median region fairly strongly
swollen; sulcus originating on the umbo at the beak, shallow and inconspicuous,
widening slightly and nearly disappearing at the anterior margin. Flanks bound-
ing sulcus moderately swollen and with short, steep lateral slopes.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Eiolatype Cl) Us veces bev et ees 10.3 0.7 11.8 9.6 ?
Hypotype (110790a)......... 12.6 12.0 14.8 II.9 8.0
sf GTIFZ OSA) ie Maes 13.4 12.8 16.5 2 9.7

Types.—Holotype (?): Carnegie Mus. 5512; figured hypotypes: 1107902,
110796, 117054.

Horizon and locality—Crown Point formation on Plattsburg (15’) Quad-
rangle in New York: On the south end of Valcour Island; in an old quarry
just west of New York Highway 9, southwest of Bluff Point, Lake Champlain ;
near the Normal School, 4 miles north of Plattsburg.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 489

Same formation in Vermont: Just north of the neck of Providence Island,
Plattsburg (15’) Quadrangle.

St. Martin formation in Quebec: At Belanger, 2 miles south of Cap St. Mar-
tin, Quebec.

Discussion.—This species is characterized by some primitive characters such
as the direct costae, a fairly strongly sulcate brachial valve, and wide hinge.
These features give the shell a distinctly hebertelloid appearance, but the pedicle
muscle scars are those of Mimelia. The species is closest to M. nuclea but dif-
fers from that species in its more regular form, wider hinge, and more convex
valves.

MIMELLA WARDELLANA Cooper, new species
Plate 90, D, figures 35-38

Shell of about medium size for the genus, subrectangular in outline, wider than
long. Sides fairly strongly rounded; anterior margin gently rounded to nearly
straight ; anterior commissure broadly uniplicate. Multicostellate, costellae low,
rounded, crowded, about 13 in 5 mm. at the front margin.

Pedicle valve moderately convex in lateral profile with the most convex part
in the posterior half, anterior half somewhat flattened. Anterior profile broadly
and moderately convex. Umbonal region swollen; median region moderately
convex ; anteromedian half depressed to form a shallow and wide sulcus. Flanks
bounding sulcus gently swollen. Lateral and posterolateral slopes long and only
moderately steep. Tongue broad and rounded.

Brachial valve slightly deeper than the pedicle valve, fairly strongly convex
in lateral profile and with the maximum convexity in the median region; anterior
profile strongly convex with the maximum height of the arch in the median
region and with long and steep slopes to the margins. Umbonal and median re-
gions inflated ; anteromedian area forming a moderately broad but indistinct fold.
Lateral descent from median region long and steep to the margins and postero-
lateral extremities.

Pedicle interior with muscle field subquadrate in outline, the diductor tracks
narrow and nearly parallel, the adductor scars situated on a tonguelike elevation
protruding slightly anterior to the front margin of the field. Brachial valve with
deep notothyrial cavity, high cardinal process, and stout median ridge.

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
Holotype (brachial valve)........ ? 14.9 20.9 13.5 6.7
Paratype (pedicle valve 117055b).. 16.3 ? 20.9 15.0 ? 6.5

Types.—Holotype: 117055a; figured paratype: 117055b; unfigured paratype:
117055¢,d.

Horizon and locality Wardell formation in Tennessee: In Raccoon Valley,
$ mile northeast of Fleanor Mill, Powell Station (T.V.A. 137-SE) Quadrangle.

Discussion.—This species is characterized by strongly convex valves and fine

490 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

costellae. It is also featured by a fairly narrow uniplicate wave in the anterior
commissure suggestive of M. sulcata. It differs from that species in having a
strongly swollen umbo and less convex pedicle valve.

MIMELLA sp. 1
Plate 91, D, figures 19-24

Shell of medium size, subrectangular in outline with the hinge narrower than
the greatest width which is at the middle. Anterior commissure rectimarginate.
Sides very gently rounded. Cardinal extremities prominent. Surface multicos-
tellate, costellae uneven, crowded, about II in 5 mm. at the anterior margin.

Pedicle valve gently convex in lateral profile with the posterior half convex
and the anterior half somewhat flattened. Anterior profile very gently and
broadly convex. Umbonal and median regions gently swollen; anterior region
flattened. Lateral and posterolateral slopes long and gentle. Interarea long and
strongly apsacline ; beak gently incurved.

Brachial valve evenly and moderately convex in lateral profile with the maxi-
mum convexity at about the middle. Anterior profile fairly strongly convex with
long but moderately steep lateral slopes.

Measurements in mm.—117056a, lerigth 16.2, brachial length 15.9, width 20.4,
hinge width 18.0, thickness 10.4.

Figured specimens.—117056a,b.

Horizon and locality—Elway formation in Tennessee: On U. S. Highway
25W, 4.7 miles south of Clinton, Powell Station (T.V.A. 137-SE) Quadrangle.

Discussion.—This species suggests M. laticardimia but has a few differences.
The pedicle valve is somewhat more swollen, the interarea is more apsacline, the
cardinal extremities less obtuse, and the umbo faintly sulcate. Only two speci-
mens are available, both of which are imperfect ; consequently, no specific name
has been applied.

MIMELLA sp. 2
Plate 91, G, figures 29-34

Shell small to medium size for the genus, wider than long, hinge narrower
than the greatest shell width at the middle. Sides rounded, anterior margin
broadly rounded; anterior commissure rectimarginate. Surface multicostellate,
costellae fine, closely crowded, numbering about 17 in 5 mm. at the front margin.

Pedicle valve gently convex in lateral profile; anterior profile broadly convex
but the median ridge rounded and with long, gentle lateral slopes. Umbonal
region somewhat swollen ; median region gently inflated to form a poorly defined
fold. Lateral areas flatly convex. Interarea strongly apsacline, gently curved.

Brachial valve gently convex in lateral profile; anterior profile gently and
broadly convex, the median region slightly depressed. Umbo marked by a shal-
low sulcus that extends from the beak to the anterior margin. Flanks bounding
sulcus gently swollen; posterolateral extremities prominent, marked off by long
gentle slopes.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 491

Measurements in mm.—117057, length 7.9, brachial length 8.2, width 10.7,
hinge width 9.3, thickness 4.1.

Figured specimen.—117057.

Horizon and locality—Tulip Creek formation in Oklahoma: 152 feet above
the top of the basal sand, on the first creek east of U. S. Highway 77,
SESNEILNE4S sec. 25, T. 2S., R. 1 E., Carter County.

Discussion.—This is clearly an immature form probably not directly compara-
ble to any of the described species.

MIMELLA sp. 3
Plate 91, J, figure 40

This is a large species which was taken from limestone of the Lincolnshire
formation along the railroad just east of Strasburg Junction, Strasburg (15’)
Quadrangle. The brachial valve only is represented, but it indicates a species
larger than M. laticardinia. It is 22 mm. long by 29 mm. wide.

Figured specimen.—117058b.

Family SKENIDIIDAE Kozlowski, 1929

Small subpyramidal Orthacea probably derived out of Finkelnburgiidae, hav-
ing a free spondylium, a cruralium, and fulcral plates forming the sockets.

Genus SKENIDIOIDES Schuchert and Cooper, 1931

Skenidioides ScHUCHERT and Cooper, Amer. Journ. Sci., vol. 22, p. 243, 1931; Mem. Peabody
Mus. Nat. Hist., vol. 4, pt. 1, p. 71, 1932.

SKENIDIOIDES ANTHONENSIS (Sardeson)
Plate 98, H, figures 31-37
Skenidium anthonensis SARDESON, Minnesota Acad. Nat. Sci., Bull. 3, p. 333, pl. 4, fig. 7, 1892.
Scenidium halli Hatt and CLARKE (part), Pal. New York, vol. 8, pt. 1, p. 242, pl. 7A,
figs. 37-39, 1892.
Scenidium anthonensis (Sardeson) WINCHELL and ScHUCHERT, Geol. Minnesota, vol. 3,
p. 381, figs. 20-23, 1893.
Skenidioides anthonensis (Sardeson) ScHucHERT and Cooper, Mem. Peabody Mus. Nat.
Hist., vol. 4, pt. 1, p. 71, 1932.

Shell small for the genus, wider than long, width about twice the length ; cardi-
nal extremities acute; sides obliquely rounded and sloping toward the middle;
anterior commissure strongly and narrowly sulcate; surface costate, 10 to II
costae on each side of the fold and sulcus; fold marked by 3 or more costae, the
outer 2 bifurcated, the inner ones may or may not be bifurcated depending on
the size attained; sulcus with a similar arrangement.

Pedicle valve gently convex in lateral profile; broadly triangular in anterior
profile; anterior commissure deeply emarginate at the fold; flanks bounding
fold gently convex in anterior profile ; fold only slightly elevated. Interarea long,
beak gently curved.

492 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve slightly convex in lateral profile; gently and broadly convex
in anterior profile; tongue short and narrowly rounded; sulcus deep, originating
at the umbo; flanks bounding sulcus gently convex.

Measurements in mm.—Hypotype (24207a), length 1.4, brachial length 1,5,
midwidth 2.9, hinge width 3.3, thickness 1.2.

Types.—Figured hypotypes: 24207a, 4891 1a,b.

Horizon and locality.—Platteville formation in Minnesota: At Minneapolis.

Same formation in Illinois: At Dixon, Dixon (15’) Quadrangle.

Discussion.—This species is distinguished by its considerable width even in
adult form, its fairly strong, sharp, and regular costae, and low fold. It has been
the practice to place this species in the synonymy of S. halli, but it is actually a
much smaller shell, with less numerous costae on the flanks, much lower fold,
and a narrower and shallower sulcus. The Minnesota species is also suggestive
of S. perfectus from the Bromide formation (Pooleville member), but that is a
narrower species with more distant costae and stronger fold and sulcus.

SKENIDIOIDES BILLINGSI Schuchert and Cooper
Scenidioides billingsi SCHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1,
p. 72, pl. 10, figs. 6, 8, 10-14, 1932.
Types.—Holotype: Y.P.M. 20138.
Horizon and locality—Rockland formation, Paquette Rapids in Canada: On
Ottawa River, Ontario.

SKENIDIOIDES CONVEXUS Cooper, new species
Plate 99, E, figures 24-34

Shell of about medium size for the genus, width about twice the length ; cardi-
nal extremities acutely angular; sides gently rounded and directed obliquely
toward the middle of the valve; anterior margin truncated ; anterior commissure
deeply sulcate. Surface costate, costae numbering 6 to 9 on the flanks and gen-
erally 5 on the fold.

Pedicle valve moderately to fairly strongly convex in lateral profile; anterior
profile moderately and fairly evenly convex, the median region only moderately
carinated by the fold. Fold formed by a fascicle of 5 costae, 2 bifurcating at the
beak, 2 bifurcating just anterior to the beak, and the fifth implanted or bifurcated
between the latter 2. One of the median ribs usually swollen and forming the
crest of the fold. Flanks slightly swollen and merging gently into the fold; inter-
area long and apsacline.

Brachial valve flat in lateral profile in the posterior half but bent toward the
pedicle valve in the anterior half; anterior profile almost flat to gently convex ;
sulcus narrow and deep, occupied by 2 costae on its sides and 2 or 3 implanted
at the front. Flanks narrowly but gently swollen; posterolateral areas flat to
gently concave.

Interior of pedicle valve with short and shallow free spondylium; brachial

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 493

interior with narrow and shallow notothyrial cavity ; brachiophore plates attached
high on median septum.

Measurements in mm.—Holotype, length 2.4, brachial length 1.9, midwidth
3.2, hinge width 3.9, thickness 1.6,

Types.—Holotype: 117070a; figured paratypes: 117070b-d.

Horizon and locality—Pratt Ferry formation (lower 3 feet) in Alabama: 0.2
mile south of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species has a deep sulcus and moderately strong fold. The
brachial valve is fairly deep, and the costae are strong. It differs from S. costatus
in having a more convex brachial valve with a deeper sulcus. The shape of the
Alabama species is also considerably different from that of the Virginia form.

SKENIDIOIDES COSTATUS Cooper, new species
Plate 97, D, figures 38-48

Shell of about usual size for the genus, wider than long, with acutely angular
and slightly auriculate cardinal extremities, gently sloping lateral margins, and
broadly rounded to truncate anterior margin. Lateral profile planoconvex. Sur-
face marked by about 19 to 21 strong costellae in the adult. The costellae appear
in 3 generations. In a young valve 1.5 mm. in length, 13 primary costae are
present which increase by intercalation to 19 or 21. In all stages of growth the
median costa is stronger and more elevated than the others and forms a fold.
Intercalation on each side of median costa takes place about one-third the length
from the beak.

Pedicle valve evenly and strongly convex in lateral profile with the greatest con-
vexity located at about the middle; in anterior profile this valve is subcarinate
and the central costa is slightly elevated above those forming the flanks. Flanks
flat in profile and moderately steep. Interarea long, slightly curved near the beak,
and strongly apsacline.

Brachial valve flat in anterior profile. Umbo slightly convex, but just anterior
to it a narrow sulcus forms which deepens and widens rapidly anteriorly to oc-
cupy about half the width of the valve at the front. Seven costae occupy the
sulcus. Shell surface between the costae bounding the sulcus and the cardinal
extremities perceptibly but only slightly concave.

Interior: Pedicle valve with long, slender teeth and short, shallow free
spondylium. Median septum of brachial valve moderately thick and greatly ele-
vated, so that the valve is separated into two parts. Notothyrial cavity shallow
and narrow ; brachiophores long and slender.

Measurements in mm.—

Hinge
Length Width width Thickness
Fidlotype sree oh. iteee tis ogetd dooreens 3.0 4.2 4.9 17)
IPE elgg sa Willy. o 270) ee eee 1.5 3.0 37, 0.7

Types.——Holotype: 117072f; figured paratypes : 117072a-c,i,j ; unfigured para-
types: 117072d,e,g,h.

494 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality—Edinburg formation (lower Liberty Hall facies) in
Virginia: 1.8 miles S. 4° W. of Bethel Church, 5.9 miles east of Harrisonburg,
Harrisonburg (15’) Quadrangle: 4 miles southwest of Bland.

Red Knobs formation in Tennessee: 6 miles east of Knoxville.

Discussion.—This species is characterized by the strength of its ornamenta-
tion, the strong median costa which forms a prominent fold, late intercalation of
the secondary generation of costae, the deep and wide sulcus in the brachial
valve, and the flatness of the same valve.

As the ornamentation is the most distinctive feature of this little shell, a few
more remarks are necessary. A specimen 1.5 mm. in length may show only pri-
mary costellae, but two specimens actually somewhat shorter show intercalation
of the secondaries on each side of the median costa, and occasional costae else-
where on the front margin. The median costa maintains its individuality although
the secondary costae intercalated on each side of it are also slightly elevated.

The interiors of both valves of this species are characterized by the robust
development of septa and spondylium. The latter is short and shallow and sup-
ported by a considerable thickening at the posterior.

The outline and general form of S. rectangulatus are like those of S. costatus,
but the former is less strongly costate and has a pedicle valve with more gentle
lateral profile. The Benbolt species, S. mediocostatus, is fairly strongly costate,
but it does not have as strong a fold and sulcus as S. costatus.

SKENIDIOIDES ELONGATUS Cooper, new species
Plate 92, C, figures 10-22; plate 98, A, figures 1-5

Large for the genus, length and width approximately equal ; in some specimens
the width is the greater dimension, in others it is the length. Outline sub-
pentagonal ; sides rounded, sloping obliquely toward the middle; anterior margin
somewhat narrowly rounded. Anterior commissure deeply sulcate. Surface
costate, costae numbering 28 to 32, low and rounded and with intercostal spaces
narrower than the costae. Costae mostly direct from beak to anterior margin, but
intercalation takes place along the margin of large specimens. Fold with a pri-
mary bifurcation at the beak and 3 sets of intercalated costae anteriorly to pro-
duce 8 costae. Corresponding ribbing in sulcus.

Pedicle valve evenly and gently convex in lateral profile; anterior profile sub-
carinate ; beak often distorted; umbo narrowly swollen; fold narrowly convex;
flanks flattened and steep to the margins. Interarea unusually long, strongly
apsacline, curved and occasionally distorted.

Brachial valve gently convex in lateral profile with the anterior bent fairly
strongly toward the pedicle valve; anterior profile broadly and gently convex but
with the median region sulcate. Sulcus originating about 4 mm. anterior to the
beak, widening and deepening anteriorly to occupy nearly half the width at the
front margin. Tongue moderately long and rounded. Flanks bounding sulcus
narrowly rounded ; posterolateral areas flattened to gently concave.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 495

Measurements in mm.—

Brachial Hinge ‘
Length length Width width Thickness
Holotype ie... dsnoteacdt. 7.9 6.7 7.3 75 4.3
Paratype (117073b)..... 7.0 6.0 6.4 6.8 4.0
= (LI7073C) «0.0: 5.5 4.3 5.8 6.0 3.2
_ CELZO/30) 0am > 6.2 4.9 7.0 2.9 3.5

Types.—Holotype: 117073a; figured paratypes: 117073b,c,e; unfigured para-
type: 117073d.

Horizon and locality—Martinsburg formation (lower part with Brongniar-
tella= Salona), in Virginia: On Virginia County Road 617=910, 0.15 mile north
of Green Mount Church, Broadway (15’) Quadrangle.

Discussion.—This is the largest species yet found in the middle Ordovician
rocks of the United States. It is not therefore directly comparable to any of the
other species herein described. Young stages suggest S. rectangulatus but usu-
ally are somewhat wider than that species and with a shallower sulcus.

SKENIDIOIDES HALLI (Hall and Clarke)
Plate 08, G, figure 30

Skenidium halli Sarrorp, Geol. Tennessee, p. 287 (not defined), 1860.
Scenidium halli Safford (in part) Hatt and CLARKE, Pal. New York, vol. 8, pt. 1, p. 242,
pl. 7A, figs. 33-36, 1802.

Fairly large for the genus, wider than long and with the hinge usually form-
ing the greatest width. Valves unequally convex and of unequal depth, the
pedicle valve having the greater depth. Anterior commissure strongly sulcate.
Surface costate ; costae varying in number from about 25 to 35. Increase in num-
ber of costae taking place by intercalation, most of the costae being primary ;
intercalation most frequent near the front of the fold. Costae crowded in the
median region.

Pedicle valve hemipyramidal; gently convex in lateral profile and strongly
arched to subcarinate in anterior profile. Umbo gently convex. Fold originating
about one-fifth the length from the beak; fold low posteriorly, elevating and
widening anteriorly to occupy about one-third the width. Flanks immediately
adjacent to fold flat to slightly concave; slope of flanks to margins moderately
steep. Interarea long, strongly apsacline to nearly procline.

The young brachial valve is nearly flat, but with growth the shell becomes
gently to moderately convex with a tendency to a weak geniculation of the
anterior. The sulcus originates near the beak and increases rapidly in depth and
width to the front where a short tongue is developed. As many as 9 costae may
occupy the sulcus at the front. Flanks bounding sulcus gently swollen; areas
between flanks and cardinal extremities gently concave.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (pedicle valve 117074a)..... 3:3 ? 4.5 5.0 ?

‘7 (brachial valve 117074c).... ? 2.6 4.4 4.2 ?

496 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Figured hypotype: 117074; measured hypotypes: 117074a,c.

Horizon and locality.—Lebanon limestone in western Tennessee: At Colum-
bia, Maury County ; 3 miles east of Murfreesboro, Rutherford County ; Lavergne,
Rutherford County ; cut on U. S. Highway 241, 2.1 miles north of the Bedford-
Rutherford County line in Rutherford County; behind Roy Holt’s gasoline sta-
tion on Tennessee Highway 10, 1.2 miles south of Lebanon town limits, Wilson
County.

Discussion.—This species is abundant in the Lebanon limestone of the Central
Basin of Tennessee but is rare elsewhere. It can be recognized by the moderate
convexity of the brachial valve, the strong median sulcus, but more particularly
by the fasciculate arrangement of the costae on the fold. This type of fascicula-
tion is common in many of the species of this genus, and it is to those species that
S. halli must be compared.

Skenidioides halli is about the same size as S. platys, but the Lebanon lime-
stone species possesses a more convex profile in both valves. Skenidioides okla-
homensis is suggestive of the West Tennessee species but is somewhat bigger,
more angular, with a stronger fold and sulcus and stronger costae.

SKENIDIOIDES MEDIOCOSTATUS Cooper, new species
Plate 97, C, figures 19-37

Shell fairly large for the genus, with the hinge forming the widest part. Lateral
margins sloping toward the middle; anterolateral extremities broadly rounded
and the anterior margin truncate. Anterior commissure strongly sulcate. Pro-
file planoconvex. Ornamentation variable, a broad central costa flanked by 9
to 12 costae. Most costae primary ; intercalated costae few and occurring chiefly
on each side of the median costa.

Pedicle valve slightly convex in lateral profile; more strongly convex in an-
terior profile. Umbo slightly convex; fold increasing in prominence gradually
to the anterior margin. Flanks flat in profile, their slope moderate. Interarea
long, nearly flat and nearly procline. Spondylium broad and shallow.

Brachial valve nearly flat in all profiles; sulcus originating at the umbo and
extending to the front margin where it occupies somewhat less than half the
width ; 5 to 6 costae occupy the sulcus. Flanks bounding sulcus slightly convex.
Region between flanks and cardinal extremities very slightly concave.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
TIGIGE DE, seisink wlalaiaiaus’ ce 3.0 2.5 4.0 4.5 2.0
Paratype (117075b)..... 2.6 2.5 4.0 4.7 1.5
‘s (TI7O75a) LU 2.5 2.6 3.9 4.4 na

Types.—Holotype: 117076a; figured paratypes: 117075a-c, 117077¢,d,j; un-
figured paratypes: 117076b, 117077a,b,e-i,k,l.

Horizon and locality.—Benbolt formation in Virginia: In the vicinity of Rye
Cove, Clinchport (T.V.A. 188-NW) Quadrangle; 0.2 mile south of the middle
fork of Moccasin Creek, 14 miles due south of Hansonville, Hansonville (T.V.A.

BART VE CHAZYAN AND RELATED BRACHIOPODS—COOPER 497

205-SW) Quadrangle; north side of Highway 19, about 1 mile due north of
Belfast Mills, Saltville (T.V.A. 212-NE) Quadrangle.

Chatham Hill formation in Virginia: Virginia Highway 113, Marion-Chatham
Hill road, 6 miles north of Marion, Chatham Hill (T.V.A. 218-NE) Quadrangle.

Discussion.—This species is characterized by its angular outline, strong costae
on the flanks bounding the fold, narrow and moderately deep sulcus, and low
fold marked prominently by 1 costa stronger than the others in a fascicle num-
bering about 5 costae. To compare with S. costatus see discussion under that
species. It is suggestive of S. rectangulatus but differs in its less rectangular
form, lesser length, and deeper, narrower sulcus. The ornamentation of S. con-
vexus is not unlike that of S. mediocostatus, but the former species is more
transverse and has a deeper sulcus. The form of S. obtusus is like that of the
Benbolt species, but it has more numerous ribs, a hinge narrower than the great-
est shell width, and a less deep sulcus.

SKENIDIOIDES OBTUSUS Cooper, new species
Plate 97, B, figures 13-18

Shell of about medium size for the genus, wider than long; subrectangular in
outline ; hinge as wide as, or slightly narrower than, the greatest width which is
near the middle; cardinal extremities rounded, obtuse or nearly a right angle
in the adult, auriculate in the young; sides rounded; anterior margin broadly
rounded ; costae numbering Io or 11 on the flanks; narrowly rounded and with
intercostal spaces about equal to the width of the costae; fold and sulcus marked
by a number of costae varying from 5 to 9.

Pedicle valve gently convex in lateral profile with the umbo somewhat more
convex than the rest ; anterior profile subcarinate and strongly convex, the pedicle
valve having great depth; fold low, best defined at the front; flanks gently
swollen but with steep slopes to the margins. Interarea long, with large del-
thyrium, strongly apsacline.

Brachial valve slightly convex in lateral profile, nearly flat in anterior profile;
sulcus only moderately deep but marked centrally by a narrow and deep trough
corresponding to the median costa of the pedicle valve ; width of sulcus not equal
to half the shell width. Flanks bounding sulcus gently swollen; posterolateral
areas varying from gently convex to gently concave.

Interior of pedicle valve with moderately deep free spondylium ; brachial in-
terior with deep, wide, and long notothyrial chamber ; brachiophore plates low
on median septum.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
lallagne, Mate Goren ie 3:3 3.0 4.5 4.2 2.2
Paratype (117078c)..... 2.6 2.4 3.7 3.4 1.7

Types.—Holotype: 117078a; figured paratype: 117078b, unfigured paratypes:
117078c,d.

498 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality—Edinburg formation (shale near middle of the Nidulites
zone) in Virginia: 100 yards south of Battlefield Crystal Cavern entrance on
U. S. Highway 11 at Hupp Hill, 1 mile north of Strasburg, Strasburg (15’)
Quadrangle.

Discussion.—The chief feature of this species is the narrow hinge, and in this
respect it is unlike any of the others described herein except S. elongatus, but it
is much smaller than that species. This species is like S. rectangulatus but differs
in strength of costae and narrower hinge.

SKENIDIOIDES OKLAHOMENSIS Cooper, new species
Plate 97, A, figures 1-12; plate 08, E, figures 24-27

Shell large for the genus, wider than long, with the width not quite twice the
length. Cardinal extremities acutely angular; sides gently rounded, sloping
obliquely toward the middle. Anterior margin narrowly rounded; anterior com-
missure widely and deeply sulcate. Surface costate, costae numbering about 30
on an adult; costae narrowly rounded; intercostal spaces narrower than the
costae ; except for the fold, intercalations few and near the front margins.

Pedicle valve deep, nearly flat in lateral profile in the young but gently convex
in adults ; anterior profile broadly convex with median region somewhat carinate.
Fold orginating at beak, marked by a complicated fascicle consisting of a thick-
ened median costa on the side of which 2 or more costae are implanted. This
median costa intercalated between 2 primary costae at beak. Flanks bounding
sulcus gently convex and with moderate slopes to the sides ; interarea long, nearly
catacline in the young, strongly apsacline in adults.

Brachial valve unevenly convex in lateral profile, the posterior half nearly flat
but the anterior half convex and bent strongly toward the pedicle valve ; anterior
profile broadly convex; umbo flat; sulcus originating a fraction of a millimeter
anterior to the umbo, widening and deepening anteriorly but with a deeper, nar-
row track in the median part which corresponds to the thickened costa of the
fold; sulcus occupied by 8 costae ; width of sulcus not quite equal to half the shell
width. Flanks bounding sulcus narrowly and gently inflated; posterolateral
extremities gently concave.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
EL OIOty Dey hemi cesiecs ocoaa 3.8 3.5 5.4 6.0 2.2
Paratype (117079b)..... 4.0 3.5 4.6 5.6 2.5
= CETZOZOC Y's ws: « 3.4 3.0 3.8 4.6 1.9
ia (170700) eo... 2.6 2.6 4.4 5.0 T7

Types.—Holotype: 117079a; figured paratypes: 117079d-f, 118007a-d; un-
figured paratypes: 117079b,c, 118007e-¢g.

Horizon and locality—Bromide formation (Mountain Lake member) 30 to 34
feet below top of Decker’s bed 10 in Carter County, Okla.; On Tulip Creek,
SWINW34NEI sec. 25, T. 2 S., R. 1. E.; north of the middle of sec. 32, T. 2 S.,
R. 2 E., 2 miles northeast of Springer.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 499

Discussion—This species attains a fairly large size and is therefore compara-
ble to S. halli, S. transversus, and S. rectangulatus. It is characterized by strong,
direct, and somewhat distant costae, strong fold and sulcus, and nearly catacline
interarea. Skenidioides oklahomensis differs from S. halli in its larger size,
stronger and more distant costae, catacline interarea, and narrower and deeper
sulcus. Skenidioides transversus is more transverse, as its name implies, than
the Oklahoma species, and its fold and sulcus are much less pronounced. Skeni-
dioides rectangulatus approaches the Oklahoma species in size, costation, and
strength of fold and sulcus but differs in proportions. Its lateral extremities are
squarer and the outline more quadrate.

SKENIDIOIDES PERFECTUS Cooper, new species
Plate 97, E, figures 49-54; plate 98, D, figures 18-23

Shell of about medium size for the genus, wider than long, not quite twice as
wide as long ; cardinal extremities acute; sides sloping steeply toward the middle
and gently rounded; anterior margin nearly straight or medially emarginate.
Anterior commissure deeply sulcate. Surface costate, 6 costae on the fold, 8 to
g on the flanks and 6 to 8 in the sulcus; costae and intercostal spaces of about
equal width.

Pedicle valve gently convex in lateral profile; anterior profile subcarinate ;
fold prominent, elevated, formed by a fascicle of costae; fascicle formed by a
single rib which bifurcates after 1 mm., another bifurcated median rib located
inside the bifurcation; median fascicle with a costa on each side at the base of
the fold. Flanks bounding fold barely convex. Interarea long, posterior margin
nearly straight, and beak low and inconspicuous; interarea nearly catacline.

Brachial valve in lateral profile flat in the posterior half but convex toward
the pedicle valve in the anterior half; anterior profile perceptibly convex but with
the median region narrowly sulcate. Sulcus originating at the beak which is
smooth and flat ; sulcus deepening and widening anteriorly but not equaling half
the width at the front margin; flanks bounding sulcus perceptibly convex; pos-
terolateral extremities gently concave.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
EVOIOLEY Oh else asa hugs tee, > 2.2 2.2 3.4 3.9 1.4
Paratype (117081) ..... 2.6 2.4 3.8 4.1 1.6

Types.—Holotype: 117080; unfigured paratype: 117081; figured specimens:
117082b,c, 109987d.

Horizon and locality—Bromide formation (Pooleville member—O-xoplecia
gouldi zone) in Carter County, Okla.: at Rock Crossing of Hickory Creek, ap-
proximately center sec. 35, T. 5 S., R. 1 E., Criner Hills; NW4 sec. 26, T. 5 S.,
R. 1 E.; SE4 sec. 32, T. 2 S., R. 2 E., about 2 miles northeast of Springer.

Discussion—Skenidioides perfectus is a small species suggesting S. anthonen-
sis, S. costatus, S. convexus, and S. rectangulatus. The Oklahoma species dif-

500 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

fers from S. anthonensis in its more angular outline and stronger folding. It
differs from S. costatus in the rib development, in having a less convex lateral
profile than the Virginia form, and in having a stronger fold. The Oklahoma
species differs from S. convexus in its less rounded lateral profile of the pedicle
valve and its less deep sulcus. Resemblance to S. rectangulatus is quite strong,
but the Virginia species has a broader sulcus, squarer outline, and more apsacline
interarea,
SKENIDIOIDES PLATYS Cooper, new species

Plate 98, F, figures 28, 29

Shell fairly large for the genus, wider than long with the width about 14 times
the length; cardinal extremities acute; sides rounded and obliquely directed
toward the middle; anterior margin somewhat nasute; anterior commissure
deeply sulcate. Costae narrowly rounded and with intercostal spaces about equal
to the width of the costae; 10 or II costae on the flanks and 8 to 10 on the fold
and sulcus.

Pedicle valve barely convex in lateral profile; anterior profile strongly con-
vex and median region narrowly rounded. Fold wide, prominent, multicostate,
moderately elevated, formed by a complicated fascicle consisting of an unbifur-
cated pair on the outside, another unbifurcated pair inside the previous two, and
a median intercalation all occupying the posterior half. Median intercalated costa
bifurcating near the middle; the other costae may or may not bifurcate near the
margin. Flanks flat to gently convex; interarea long and apsacline.

Brachial valve nearly flat in the posterior half but bent toward the pedicle
valve when viewed from the side; anterior profile nearly flat; sulcus deep, oc-
cupying about one-third the width at the front margin; flanks bounding sulcus
gently convex; posterolateral areas gently convex. Brachial interior with nar-
row, shallow, and short notothyrial platform.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
isletipe ti 25). ve vy rake 3.8 ? 5.4? 5.7 1.9
Paratype’ (117083a)" occ2)- 27 3.4 3.8 ?

Types.—Holotype: 117084; figured paratype: 117083a.

Horizon and locality—Little Oak formation in Alabama on the Bessemer
Iron District (15’) Quadrangle; 600 feet east of the intersection of the Cahaba
Valley road with the Helena road, 4 mile north of Pelham; 1 mile north of
Pelham.

Discussion.—This species is characterized by its flattened profiles and shallow
pedicle valve. The species resembles S. halli most but is more strongly costate
and has a more prominent fold and sulcus as well as less convex profiles.

SKENIDIOIDES RECTANGULATUS Cooper, new species
Plate 98, B, figures 6-10

Shell of about medium size for the genus, wider than long, subrectangular in
outline with cardinal extremities nearly a right angle, but acute nevertheless ;

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 501

sides nearly straight, sloping slightly medially ; anterolateral extremities some-
what broadly rounded; anterior margin gently rounded to faintly emarginate.
Anterior commissure deeply and widely sulcate. Surface costate, costae nar-
rowly rounded ; intercostal spaces about equal to the width of the costae. Costae
numbering about 24, with 10 in the broad sulcus and 3 marking the carinate
part of the fold. Intercalation in 2 generations, 1 about a millimeter anterior to
the beak and the other near midlength or somewhat anterior thereto.

Pedicle valve deep but only gently convex in lateral profile; anterior profile
strongly convex and narrowly rounded in the middle ; median region subcarinate ;
fold not clearly demarcated from the flanks but the median fascicle consisting of
a bifurcated pair, and the intercalated swollen costa intercalated in the pair is
slightly elevated. Flanks flattened; lateral slopes steep. Interarea long and
strongly apsacline ; beak prominent.

Brachial valve faintly convex in lateral profile and broadly and gently convex
in anterior profile. Umbo sulcate ; sulcus wide, deepening and widening anteriorly
to occupy more than half the width at the front margin; flanks bounding sulcus
perceptibly inflated, fairly narrow ; posterolateral extremities gently concave.

Measurements in mm.—Holotype, length 3.8, brachial length 3.1, width 4.4,
hinge width 4.8, thickness 2.3.

Types.—Holotype: 117085c; unfigured paratypes: 117085a,b.

Horizon and locality—Oranda formation in Virginia: Along the railroad
4 mile west of Strasburg, Strasburg (15’) Quadrangle; 0.6 mile west of Linn-
ville Station, Broadway (15’) Quadrangle.

Same horizon in Pennsylvania: 1 mile north of Guilford Springs, 25 miles
southwest of Chambersburg, Chambersburg (15’) Quadrangle.

Discussion—tThis species is characterized by its squarish form, its cardinal
extremities almost forming a right angle, broad and deep sulcus but broad and
not strongly elevated fold. The species suggests S. elongatus to which it may
actually be ancestral, but it does not have the extravagant development of that
species. Its squarish outline will help to separate it from most of the other species
described herein except S. obtusus. It differs from the latter in its wider hinge
and stronger and more distant costae.

SKENIDIOIDES TRANSVERSUS Cooper, new species
Plate 98, C, figures 11-17

Shell large for the genus, width approximately twice the length; cardinal ex-
tremities acutely angular; sides gently rounded, sloping obliquely toward the
middle; anterior margin nearly straight; anterior commissure sulcate; sulcus
shallow. Surface costate, costae broad, rounded, low, and separated by narrow
intercostal spaces. Costae numbering about 24.

Pedicle valve evenly and gently convex in lateral profile; anterior profile
broadly and fairly strongly convex; umbonal and median region moderately
swollen ; fold inconspicuous, not elevated but forming the crest of the median
swelling ; costae on fold 4 in number, consisting of 2 lateral costae extending to

502 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

and meeting at the beak and an intercalated costa between the lateral 2 which
bifurcates the branches extending to the anterior margin; flanks bounding fold
gently swollen. Interarea long and strongly apsacline.

Brachial valve slightly convex in lateral profile; interior profile broadly and
gently convex; umbo gently swollen; fold originating on the umbo, shallow and
narrow; occupied by 3 costae. Tongue broad. Flanks bounding sulcus gently
inflated ; posterolateral areas flattened.

Interior of pedicle valve with small teeth and broad and shallow free spondy-
lium; brachial valve with broad and shallow notothyrial cavity, long brachio-
phores, and prominent brachiophore plates.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve) ......... 3.4 ? 5.3 6.4 ¢
Paratype (brachial valve 117086d).. ? 2.8 5.3 5.9 ?

Types.—Holotype: 117086c; figured paratypes: 117086d,g; unfigured para-
types: 117086a,b,e,f,h,1.

Horizon and locality—Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This species is characterized by its large size and transverse
form. In these respects it differs from all others herein described. It is also
characterized by having a low fold and a shallow sulcus. This combination of
characters makes it unique.

SCAPHORTHIS Cooper, new genus
(Greek scaphos, hollow)

Subcircular to transversely subelliptical in outline; margins rounded ; anterior
commissure rectimarginate or sulcate; biconvex in profile, the pedicle valve hav-
ing the greater convexity ; brachial valve sulcate, sulcus usually shallow; hinge
narrower than the greatest shell width which is at about the middle; surface
multicostellate ; test fibrous, impunctate.

Pedicle interior with open delthyrium or with delthyrium constricted slightly
by lateral plates; delthyrial cavity deep; teeth small, sharp; fossettes moderately
deep ; dental plates short, flaring ; muscle field orthoid in pattern, somewhat heart
shaped in outline; diductor scars narrow; adductor track wide; anterior margin
of muscle field slightly thickened and often with a low median callosity anterior
to the anterior margin; vascula media divergent, many branched.

Brachial valve with deep but narrow delthyrial cavity; cardinal process with
narrowly rounded shaft but thin and bladelike myophore; brachiophores short
and stout but with fairly long, sharp points; brachiophores supported by stout
plates that converge to the median ridge and unite with it; fulcral plates small;
median ridge low, narrow, subcarinate, and extending to about the middle. Ad-
ductor field small, anterior scars separable into pairs.

Genotype.—Scaphorthis virginiensis Cooper, new species.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 503

Discussion.—This genus is characterized by its generally dalmanellid form but
is distinguished from all members of that group by its impunctate shell. The
genus is further characterized by the narrow notothyrial chamber enclosed by the
supporting plates of the brachiophores. This latter structure is similar to that
of Mimella and the Plectorthidae but differs in having the brachiophore sup-
porting plates more erect and uniting with the median ridge at its posterior end.
The genus is most closely related to Corineorthis Stubblefield described from the
Ordovician of Cornwall, England. It differs from the British genus in its strongly
biconvex valves. Corineorthis is characterized by having a concave pedicle valve.

A feature of considerable interest in this genus is the form of the brachio-
phores. These are divisible into two parts: a base and a “crus.” The base is a
short, thick plate supported by the brachiophore plates that unite with the
median ridge. The “crus” is a short, delicate, and sharp point extending from
the free end of the brachiophore.

SCAPHORTHIS KAYI Cooper, new species
Plate 55, D, figures 30-41
Corineorthis sp. Cooper and Cooper, Bull. Geol. Soc. Amer., vol. 57, p. 113, pl. 3, fig. 13, 1946.

Shell fairly large, subcircular in outline with the width slightly greater than the
length. Hinge slightly narrower than the greatest shell width which is located
at about the middle. Lateral and anterior margins broadly rounded. Surface
multicostellate, costellae appearing in 5 generations. Costellae of first 4 genera-
tions of about equal size at the front but those of the fifth generation more slender
than the rest. About 11 costellae in 5 mm. at the front margin of a valve 17 mm.
long.

Pedicle valve moderately and unevenly convex in lateral profile with the maxi-
mum convexity located in the posterior half. Anterior profile a somewhat nar-
rowly convex arch with steep sides. Beak forming an angle of about 140°,
strongly incurved, elevated. Umbonal region convex and median portion of valve
swollen; lateral slopes steep. Anterior slopes less steep than the lateral ones.
Interarea long, strongly curved, nearly orthocline.

Brachial valve gently convex in lateral profile with the maximum convexity
at about the middle; broadly and gently convex in anterior profile but with a
pronounced flattening of the median part of the profile. Umbonal region slightly
sulcate with the sulcus extending anterior to the front margin where it is very
faint. Sulcus shallow and broad. Flanks narrow, slightly convex with gentle
lateral slopes but with steeper slopes to the cardinal extremities. Interarea very
short, anacline.

Pedicle interior with short, thick dental plates defining a narrow but deep
delthyrial chamber. Muscle field elongate oval in outline, individual muscles
difficult to differentiate. Vascula media short, subparallel; ovarian impressions
small.

Brachial interior with brachiophore plates uniting with the median septum

504 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

to form a narrow but deep cruralium occupied by a slender, linear, ridgelike
cardinal process. Median ridge reaching the middle of the valve.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
EATHGEVPIC sine nic's Clues teieeuas ose ce 17.8 15.8 19.5 12.6 9.6
Paratype (1100074) «cere s. ceoee 18.0 15.6 19.5 15.4? 8.9
“ CTIGOOZE HOI i. FE 15.8? 14.2 17.8 11.6 7.0
Mf (pedicle valve 116906a). 16.9 4 18.5 12.7 4.5

Types.—Holotype: 111787; figured paratypes: 116905, 116906a, 116907a,d;
unfigured paratypes: 116906b-d, 116907b,c,e-i.

Horizon and locality Shippensburg formation (Pinesburg member) in Penn-
sylvania on the Chambersburg (15’) Quadrangle: 13 miles west of Kauffman;
0 to 50 feet above the Lowville in a field just north of the railroad cut 2 miles
southwest of Marion Station.

Same formation in Maryland: In the shaly cobbly beds between the lower
Echinosphaerites zone and the first Nidulites zone on U. S. Highway 40, just
west of the bridge over Conococheague Creek, 7 miles west of Hagerstown,
Williamsport (15’) Quadrangle.

Edinburg formation (Cyrtonotella zone) in Virginia: 3 mile north-northeast
of Glendale School, Winchester (15’) Quadrangle; 1.5 miles N. 61° E. of Edin-
burg, Edinburg (15’) Quadrangle; 500 feet southeast of U. S. Highway 11,
1 mile northeast of Toms Brook, Strasburg (15’) Quadrangle.

Discussion.—This species is the largest member of the genus so far known. It
is abundant in the lower part of the Edinburg and Shippensburg formations. It
differs from the other two known species in size, in having a nearly rectimargi-
nate anterior commissure, and in having somewhat stronger costellae.

SCAPHORTHIS PERPLEXA Cooper, new species
Plate 55, B, figures 12-26

Dalmanella sp. Burrs, Virginia Geol. Surv. Bull. 52, pt. 2, p. 42, pl. 73, figs. 24, 25, 1942.
Corineorthis sp. Cooper and Cooper, Bull. Geol. Soc. Amer., vol. 57, p. 113, pl. 3, fig. 14, 1946.

Shell small, transversely subelliptical in outline. Hinge narrower than the
maximum shell width which is located at the middle. Cardinal extremities ob-
tuse. Sides narrowly rounded. Anterior margin broadly rounded. Surface cos-
tellate, costellae appearing in 4 generations, about 4 costellae in I mm. at the front
of a valve 74 mm. long.

Pedicle valve evenly convex in lateral profile with the maximum convexity at
about the middle. Anterior profile narrowly convex medially and with steep
slopes. Beak incurved and extending posterior to the posterior margin. Umbo
narrowly convex and merging with a longitudinal median elevation or fold, the
narrow convexity of which decreases anteriorly. Flanks slightly concave and
steep sided. Interarea moderately long, curved, nearly orthocline.

Brachial valve strongly convex in lateral profile with the maximum convexity
in the posterior half. Anterior profile a broad, slightly elevated arch depressed

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 505

medially. Median sulcus originating at the beak and deepening anteriorly, shal-
low and very broadly U-shaped in section. Flanks bounding sulcus slightly swol-
len and with gentle slopes to the margins. Posterolateral slopes to the cardinal
extremities are the steepest slopes. Anteriorly the sulcus produces a short,
bluntly pointed tongue. Interarea short.

Pedicle valve interior with small teeth having small but deep fossettes. Dental
plates short and flaring. Delthyrium wide but usually more or less narrowed
by the growth of lateral (deltidial?) plates. Delthyrial cavity deep; muscle area
somewhat heart shaped and extending a short distance anterior to the ends of
the dental plates; a slight callosity at the anterior margin of the muscle field.
Vascula media diverging widely from the diductor scars.

Brachial valve interior with a short, narrow but deep notothyrial cavity formed
by the sides of the brachiophores and their supporting plates. Cardinal process
a more or less well developed simple ridge. Brachiophores long and slender,
bounding deep sockets defined by small fulcral plates. Brachiophores supported
by short plates uniting with the floor of the notothyrial cavity and the median
ridge. Anterior adductor impressions larger than the posterior pair and sepa-
rated by a low median ridge that extends to the middle of the valve.

Measurements in mm.—

Hinge
Length Width width Thickness
RAGUSA eh aac act mcihaue sce cathe 7.6 8.5 5.6 4.5
PatAyDe: (LDEGOLE) oes sae ac es ce sles 6.4 7.5 5.5 3.7
it (pedicle valve 111802m)... 8.5 0.4 6.7 3.6
7 (brachial valve 111802s)... 8.0 10.9 7.5 1.5

Types.—Holotype: 111802c; figured paratypes: 111802d,k,l,r-u; unfigured
paratypes: 111802a,b,e-j,m-q.

Horizon and locality—Effna-Rich Valley formations in Virginia: At the Por-
terfield Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quad-
rangle; Botetourt formation in Virginia: 2 miles northwest of Brownsburg,
Lexington (15’) Quadrangle.

Discussion.—This is the smallest of the three species herein described. It
is totally unlike S. kayi in size, ornamentation, and the moderately strong sulca-
tion of the anterior commissure. It differs from S. virginiensis in being smaller
and less robust, in having a more convex and subcarinate pedicle valve and finer
costellae.

SCAPHORTHIS VIRGINIENSIS Cooper, new species
Plate 55, A, figures I-11
Corineorthis sp. Cooper and Cooper, Bull. Geol. Soc. Amer., vol. 57, p. 113, pl. 3, fig. 15, 1946.
Shell fairly large, intermediate in size between S. kayi and S. perplexa; sub-
circular in outline with well-rounded sides and anterior margin; anterior com-
missure rectimarginate ; surface multicostellate, 2 to 3 narrowly rounded costellae

in I mm at the front margin of a large adult.
Pedicle valve moderately convex in lateral profile with the greatest convexity

506 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

at about the middle; anterior profile narrowly convex in the midregion with long,
flat, and steep slopes to the margins; anterior slope gently convex, long; beak
somewhat elongated and protruding; umbo narrow, swollen, the swelling con-
tinuing to the middle; umbonal slopes steep. Interarea gently curved, apsacline ;
teeth small, pointed; fossettes deep; delthyrial cavity deep; dental plates short,
divergent ; umbonal cavities shallow ; muscle field not deeply impressed, slightly
thickened anteriorly.

Brachial valve moderately convex in lateral profile and with the greatest con-
vexity in the posterior third ; anterior profile broadly convex, indented medially,
lateral slopes short, not steep. Fold originating at the umbo, widening anteriorly
to the front margin where it is quite shallow; flanks bounding sulcus gently
swollen ; slopes to posterolateral areas gentle. Notothyrial cavity deep, cardinal
process a low, simple ridge; median ridge moderately high; brachiophores long
and slender; brachiophore supports slender and discrete, fulcral plates well
defined.

Measurements in mm.—

Brachial Hinge
Length length Width width ‘Thickness
Holotype (pedicle valve)........... 10.5 i 12.2 9.1 3.1
Paratype (lTr7 Gea?) o.'s.00'4 cae ree 8.6 7.4 9.5 7.1 3.9
ia (pedicle valve 116903e)... 11.2 ? 12.3 10.3 3.1
“ Os ET TOOORT).< ot Oly, ? 10.6 8.3 Fr
4 (brachial valve 111788c).. ? 10.1 12.7 10.2 2.1
% Cees jum LOGOS) sues 9.0 TZ 9.3 1.6

Types.—Holotype: 116903c; figured paratypes: 111788a,c,e, 116903a,b,e; un-
figured paratypes: 111788b,d, 116903¢,d,f-1.

Horizon and locality —Chatham Hill formation in Virginia: 1.2 miles S. 31° E.
of Sharon Springs, Burkes Garden (15’) Quadrangle.

Discussion—This species is intermediate in size between S. kayi and S. per-
plexa but differs strongly from both. From S. kayi it differs in having a more
strongly sulcate brachial valve, and therefore a definitely sulcate anterior com-
missure. It differs from S. perplexa in being a more robust shell, in having a
more elongate beak and longer interarea, and having somewhat stronger costellae.

SCAPHORTHIS sp. 1
Plate 55, C, figures 27-29

This is a large species as indicated by the four specimens available for study.
These consist of a complete specimen, two brachial interiors, and part of a pedicle
interior. The largest specimen is 10.8 mm. long and 13.0 mm. wide at the mid-
dle. This is not as large as S. kayi nor is the species as convex or as strongly
costellate as S. kayt.

Figured specimen.—116908a.

Horizon and locality.—Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 507

TROPIDOTHYRIS Cooper, new genus
(Greek tropis, keel; thyris, opening)

Shell small to minute, subpentagonal in outline ; hinge forming the widest part ;
sides oblique; anterior margin narrowly rounded; anterior commissure deeply
sulcate ; brachial tongue long and acute; surface smooth to more or less plicate,
the plicae when present not always reaching the front margin. Impunctate.

Pedicle valve with long apsacline interarea and open delthyrium ; teeth small ;
free spondylium deep and long.

Brachial valve with deep and narrow notothyrial cavity bounded by subparallel
brachiophore plates attached to the valve floor ; brachiophores long and slender ;
sockets defined by small fulcral plates ; cardinal process long and slender, strongly
elevated within the notothyrial cavity ; median septum long and slender, strongly
elevated at the anterior end to form a partition dividing the valves. Adductor
impressions located on each side of the median septum.

Genotype.—Tropidothyris pentagona Cooper, new species.

Discussion.—This interesting little genus is undoubtedly related to Skenidioides
and is probably a lateral branch of it. The resemblance is to be seen in outline
and folding. Although a resemblance between the two genera is easy to see,
nevertheless some important exterior differences occur in the ornamentation.
The ornamentation of Skenidioides consists of narrowly rounded, usually direct
or implanted costae; some specimens of Tropidothyris may be quite smooth.
Others are marked by broad plications often indistinct and often not reaching the
margins of the shell. Furthermore, although the folding and sulcation of the two
genera are of the same type, those of Tropidothyris are much more strongly
developed.

The interior of the valves of the two genera also show differences while at the
same time showing close relationships. The free spondylium of the pedicle valve
of Tropidothyris is usually deeper than that of Skenidioides probably because its
valve is deeper and narrower. In the brachial valve the chief generic differences
occur. In Skenidioides the notothyrial chamber is generally fairly wide and shal-
low and the brachiophore plates are attached to the medium septum. When
viewed from the anterior these plates are distinctly attached to the valve floor by
callus or elevated above the floor. This is clearly the case in S. billingst Schuchert
and Cooper, the genotype. The brachiophore plates of Tropidothyris on the
other hand, do not unite with the median septum but are attached to the floor of
the valve. They make a subparallel thickening along the floor on each side of the
shaft of the cardinal process, the anterior ends often swinging toward the median
septum to close off the notothyrial cavity. The median septum and cardinal
process are like those of Skenidioides.

This little genus is known only from the Pratt Ferry locality in Alabama.

TROPIDOTHYRIS PENTAGONA Cooper, new species
Plate 99, A, figures 1-14

Shell small, subpentagonal in outline and with the hinge forming the widest
part; cardinal extremities acutely rounded; sides gently rounded, oblique; an-

508 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

terior margin narrowly rounded to nasute. Anterior commissure deeply sulcate;
lateral commissure gently convex toward the pedicle valve in the posterior half
but deeply concave toward the pedicle valve in the anterior half. Surface smooth
or marked by 3 or 4 broad plications on the flanks; the plications may or may
not reach the anterior margin.

Pedicle valve deep, gently convex in lateral profile but strongly carinate in
anterior profile; umbo swollen and beak projecting beyond the posterior mar-
gin; umbo marked by a more or less prominent ridge or plication that may ex-
tend onto the fold; fold strongly elevated and prominent, becoming more and
more elevated anteriorly ; flanks gently swollen in the posterior half and separated
from the fold by oblique, shallow depressions extending from the side of the
fold to the anterolateral extremities. Sides of fold steep but only gently convex.
Interarea long, curved, apsacline ; beak pointed and incurved.

Brachial valve nearly flat in the posterior half in lateral profile, strongly bent
toward the pedicle valve in the anterior half; anterior profile broadly and gently
convex; umbonal and posterolateral areas flattened to faintly swollen; sulcus
originating near the beak, shallow in the posterior third but widening and deep-
ening rapidly in the anterior two-thirds ; tongue long and bluntly pointed. Inter-
area short.

Interiors as described for the genus.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype th! %, YES toes 1.93 1.60 2.0 2.26 r.3
Paratype /(117087b). 2eseae: 1.68 1.42 1.93 2.00 1.4

Types.—Holotype: 117087a; figured paratypes: 117087b-e

Horizon and locality—Pratt Ferry formation (lower 3 feet) in Alabama:
0.2 mile south of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—No other species of this genus is known. The species is quite
unlike any known species of Skenidioides in its smooth to plicate ornamentation
and in the peculiar subpentagonal outline and exceptionally deep sulcus. Speci-
mens are uncommon in the insoluble residue from the Pratt Ferry limestone.

PHRAGMORTHIS Cooper, new genus
(Greek phragma, fence)

Shell small, biconvex; valves of subequal depth; having the external appear-
ance of a Dalmanella in the broad sense of the term. Anterior commissure sul-
cate. Surface multicostellate, some of the costellae swollen. Impunctate.

Pedicle valve with an elongate interarea and narrow, open delthyrium. Den-
tal plates short, stout, receding. Muscle area with poorly defined scars ; rounded
in front, often thickened and elevated a little at the front and joined to the dental
plates in such a way that the ensemble appears to be a sessile spondylium. Floor
of the valve thickened for some distance anterior to the muscle field. Vascula
media oblique, nearly straight.

PART E CHAZYAN AND RELATED BRACHIOPODS—COOPER 509

Brachial valve with a deep but narrow notothyrial cavity. Brachiophores long
and slender. Brachiophore supporting plates uniting with the median septum
to form a cruralium. Socket plates well formed. Median septum extending to
the anterior margin, slender and highest near the front. Septum nearly com-
pletely dividing the interior into 2 chambers. Cardinal process a low ridge on
the floor of the cruralium not reaching the beak.

Genotype.—Phragmorthis buttsi Cooper, new species.

Discussion.—The combination of characters in this genus mark it as unique.
Phragmorthis has some features of Skenidioides and Mystrophora but is unlike
both of them internally although the exteriors are similar. Inside the pedicle
valve the dental plates are short and receding. The teeth are small. The umbonal
cavities between the shell wall and the dental plates are usually filled with shell
material. The dental plates are usually revealed as short ridges developed on the
under side of the palintrope along the delthyrial edge. These ridges extend to
the floor of the valve at the apex of the delthyrial cavity and form its margins.

The muscle field of the pedicle valve is confined to the delthyrial cavity and is
sufficiently thickened and washed onto the sides of the delthyrial cavity to make
it appear that the dental plates and floor unite as a sessile spondylium. This is,
however, a deception. Anterior to the muscle area a thickened patch, widest at
its rear, extends and narrows anteriorly to reach a point not quite at the margin.
On each side of this thickening appear the main branches of the pallial trunks
which originate just outside and anterior to the point where the dental plates
join the floor. No delthyrial plates of any sort were observed.

The interior of the brachial valve is even more remarkable than that of the
pedicle valve. The notothyrial cavity is narrow but deep and its floor is formed
by 2 concave plates that unite on their inner sides with the top of the median
septum. On the outside they are joined to the delthyrial edge. The median line
of the notothyrial chamber is occupied by the slightly raised upper edge of the
median septum, but this does not reach the beak.

The sockets are very deep and are defined in the young by small socket plates.
In adults the socket plates are buried by shell substance that fills in the hollows
under the notothyrial cavity. The brachial processes are given off at the point
where the notothyrial plates and delthyrial edge join. The brachial processes are
long, fairly slender, and curved. On the outside they have a small thin elevated
line which joins with the socket plate.

The most striking feature of this genus is the median septum which extends
from the notothyrial cavity anteriorly to the front margin. It is highest at its
front end where it forms a blunt point. As alluded to above, the septum is con-
tinued posteriorly as a ridge in the notothyrial cavity but does not reach the beak.
This ridge undoubtedly serves as a cardinal process.

The adductor muscles were located on the floor of the valve on each side of
the median septum. They form 2 elongate scars which may be elevated on
elongated thickenings.

Close relationship of Phragmorthis to Skenidioides or Skenidium may be dis-
missed because those genera have an unsupported spondylium in the pedicle

S10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

valve. The structure of the brachial valve is also quite different in spite of the
fact that both have a high median septum.

The closest similarity to Phragmorthis is to be seen in Mystrophora which is,
however, a punctate genus. This genus also differs from Phragmorthis in hav-
ing a plate in the delthyrium of the pedicle valve. In the brachial valve the two
genera have similar septa, but the notothyrial cavity is shallower and more ele-
vated on the septum than in Phragmorthis. Kayser describes the brachial proc-
esses as short whereas those of the Ordovician genus are very long.

PHRAGMORTHIS BUTTSI Cooper, new species
Plate 146, D, figures 31-38; plate 148, B, figures 5-11; plate 148,C, figures 12-26;
plate 221, C, figures 16-22

Shell small, wider than long, strongly biconvex, with an elongate interarea on
the pedicle valve. Hinge slightly narrower than the width at the middle. Cardi-
nal extremities obtuse. Lateral margin rounded; anterior margin indented medi-
ally. Anterior commissure sulcate. Surface ornamented by fine costellae, about
4 in I mm. at the front.

Pedicle valve moderately strongly convex in anterior and lateral profiles ; front
emarginate ; valve swollen in the region from the beak to the anterior margin;
lateral and posterolateral regions somewhat swollen. Midline of valve marked
by a single costella stronger than the rest which extends from the beak to the
indentation at the middle of the front margin and which serves as a fold. Con-
centric growth lamellae bent posteriorly at this strong costella.

Brachial valve strongly convex in lateral profile and with the greatest con-
vexity at about the middle. Anterior profile bilobate. Valve divided into halves
by a narrow groove extending from the beak to the anterior margin, this groove
corresponding to the strong median costella of the pedicle valve. Flanks on each
side of groove swollen. Lateral slopes moderately steep, and steeper than those
to the median groove.

Measurements in mm.—Holotype, length 5.9, brachial length 5.0, width 6.8,
hinge width 6.2, thickness 4.2.

Types—Holotype: 116959m; figured paratypes: 116947a-c,h,i, 116959b,d,
h,k,l, 116960a-e,h,k ; unfigured paratypes: 116947d-g,j-l, 116958a-k, 116959a,c,
e-g,i,j, 116960f,g,i,j.

Horizon and locality —Effna-Rich Valley formations in Virginia: From Por-
terfield Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quad-
rangle; McNutt Quarry, 12 miles southwest of Bland, Burkes Garden (15’)
Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: 1.8 miles S. 4° W. of
Bethel Church, 5.9 miles west of Harrisonburg, Harrisonburg (15’) Quadrangle.

Arline formation in Tennessee: On north side of wagon road in glade, 4 mile
southeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Pratt Ferry formation in Alabama: On the road 0.2 mile southeast of Pratt
Ferry, Blocton (15’) Quadrangle.

Discussion.—This species is best recognized by its rotund valves, the elevated

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 5I1

median costella on the pedicle valve, and the deep, narrow sulcus on the brachial
valve. The only other species like it are those of Laticrura, but in that genus the
shell is punctate, the median ridge is low, and the sulcus of the brachial valve is
never so deep as that of Phragmorthis.

This peculiar little shell occurs in abundance in the thin limestones above the
large reef in the Porterfield Quarry, Va., and in the Pratt Ferry formation at
Pratt Ferry, Ala. In both places the shells are silicified.

PHRAGMORTHIS CRASSA Cooper, new species
Plate 126, F, figures 30-35

Shell large for the genus, subquadrate in outline, wider than long; hinge nar-
row ; cardinal extremities narrowly rounded ; sides moderately rounded ; anterior
margin broadly rounded; anterior commissure narrowly sulcate. Surface multi-
costellate, costellae numbering about 45 and spaced about 2 to the millimeter at
the front margin.

Pedicle valve gently and unevenly convex, the maximum convexity just an-
terior to the umbo and with the remainder of the valve flattened. Anterior profile
subcarinate. Umbo narrowly convex, the convexity continued anteriorly as a
low, narrow fold; flanks bounding fold flattened and descending fairly steeply
to the lateral margins. Interarea long and steeply apsacline.

Brachial valve moderately convex in lateral profile and with the maximum
convexity in the posterior third, the anterior two-thirds somewhat flattened. An-
terior profile broadly and moderately convex; sulcus originating at the umbo
and forming a narrow, steep-sided gash, widening only slightly in its passage to
the anterior margin. Flanks bounding sulcus moderately swollen and with short,
moderately steep lateral slopes. Beak strongly incurved and overhanging the
interarea of the pedicle valve.

Measurements in mm.—Holotype, length 7.4, brachial length 7.2, midwidth
8.9, hinge width 6.2, thickness 4.0.

Type.—Holotype: 116963.

Horizon and locality.—Base of Martinsburg formation (part with Brongniar-
tella= Salona formation) in Virginia: On Virginia County Road 617=910, 0.15
mile north of Green Mount Church, Broadway (15’) Quadrangle.

Discussion—This species is characterized by the subcarinate pedicle valve
and the deeply and narrowly sulcate brachial valve combined with the strong
costellae. The latter are stronger than the costellae of P. buttsi. Furthermore,
this species attains a larger size and is more deeply sulcate and carinate than the
Pratt Ferry-Effna species.

Suborder CLITAMBONITOIDEA Opik, 1934
Superfamily CLIrAMBONITACEA Schuchert, 1929

Family TRITOECHIIDAE Ulrich and Cooper, 1936

Primitive Clitambonitacea with or without a spondylium but with perforate
deltidium and chilidial plates; brachiophore supporting plates short, obscure.

512 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Subfamily TriroecH1InaAE Ulrich and Cooper, 1936

Tritoechiidae without a spondylium, the dental plates extending directly to
the floor of the valve.

Genus TRITOECHIA Ulrich and Cooper, 1936

Tritoechia Utricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 624, 1936; Geol. Soc. Amer.
Special Pap. 13, p. 160, 1938.

TRITOECHIA TYPICA (Ulrich)
Plate 77, A, figures 1-9

Deltatreta typica Ulrich in ScHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4,
pt. I, p. 206, pl. 6, figs. 10, 14, 19 (lectotype), 30, 1932.

Tritoechia typica (Ulrich) UtricnH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 1609,
pl. 33B, figs. 7-28, 1938.

Interior and exterior views of this genus and species are introduced for com-
parison with the rare genus Eremotoechia. From present knowledge the latter
appears to be related to the common Lower Ordovician (Canadian) genus.

Types.—Lectotype: 91749c; paratypes: 91749a,b,d; hypotypes: 91750a-m ;
92985a-l.

Horizon and locality —Kindblade formation, Arbuckle Mountains, Okla.

Subfamily PoLtyToEcHINAE Opik, 1934
Genus POLYTOECHIA Hall and Clarke, 1892

Polytoechia HAtt and CLarKE, Pal. New York, vol. 8, pt. 1, p. 239, 1892.—ULRIcH and
Cooper, Geol. Soc. Amer. Special Pap. 13, p. 175, 1938.

POLYTOECHIA ? OAKENSIS Butts

Polytoechia ? oakensis Burrs, Alabama Geol. Surv., Special Rep. 14, p. 116, pl. 26, figs. 25, 26,
1926.

This is a shell of uncertain generic affinities, which has never been described.
It is known only from two pictures in Butts’ report on Alabama geology. The
specimen is small, measuring 8.7 mm. long, 9.4 mm. at the middle, which is the
widest part, 7.2 mm. along the hinge, 5.7 mm. thick, and the brachial valve is
7.7 mm. long. The pedicle valve has a broad interarea which is steeply apsacline.
The beak is slightly incurved. The delthyrium is open. The brachial valve is
moderately convex in both profiles, and both valves show traces of fine radial
ornament.

The valves are so heavily silicified that few pertinent details can be seen
through the delthyrium. A thickening at the beak which forms a moderately
deep V suggests the presence of a spondylium. No details of the brachial valve
interior can be determined.

The general aspect of this shell suggests the genus Polytoechia, but no trace
of a pseudodeltidium can be detected. The specimen also suggests Butts’ Poly-
toechia symmetrica which Ulrich and Cooper (1938, p. 144) assigned to the genus

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 513

Finkelnburgia. Actually Polytoechia oakensis is unlike any Little Oak species
yet seen, and it is more like shells from the underlying Odenville formation. It
is here suggested that P. oakensis was not derived from the Little Oak, and it is
therefore not listed with that fauna,

EREMOTOECHIA Cooper, new genus

(Greek eremos, solitary; toixos, room)

Shell fairly large, valves of unequal depth and convexity, the brachial valve
having the greater depth; hinge narrower than the greatest shell width. Anterior
commissure uniplicate. Surface finely multicostellate.

Delthyrium of pedicle valve covered by a convex pseudodeltidium perforated
by a foramen at its apical end. Interarea moderately long. Delthyrial cavity wide
and shallow; dental plates short but strong, divergent. Teeth small; crural
fossettes small.

Cardinalia suggesting the Canadian genus Tritoechia. Brachial umbo greatly
swollen ; brachiophores narrow rods supported by shell substance along the sur-
face facing the brachial valve and the posterior inner wall. Median ridge rudi-
mentary or obsolete. Cardinal process large, with a short shaft, but large lobate
myophore. Chilidial plates small. Musculature indistinct.

Genotype.—Eremotoechia cloudi Cooper, new species.

Discussion.—Externally this peculiar genus has the appearance of Mimella
or a small Hebertella in the strongly convex brachial valve, the less convex
pedicle valve, and the multicostellate ornamentation. However, the presence
of a pseudodeltidium over the delthyrium, a feature not yet seen in Hebertella
and its allies, serves to separate Eremotoechia from its homeomorphs.

The internal features of Eremotoechia are totally unlike those of the Hebertel-
loids, but indicate relationship with Tritoechia and Pomatotrema of the upper
part of the Canadian period. The pseudodeltidium of the pedicle valve is per-
forated by a small foramen. The internal features of the pedicle valve are so
like those of the Tritoechiidae that this feature, too, probably conformed to the
family characters. The dental plates of Eremotoechia are shorter and more flar-
ing than is usual in Tritoechia, but this is probably caused by the lesser length
of the palintrope.

The greatest similarity to Tritoechia may be seen in the brachial valve. On
the exterior, one striking characteristic is preserved in the chilidial plates. Al-
though these are small and not conspicuous, they are characteristic of the family.
The beak and umbo of Eremotoechia are more arched and swollen than is usual
in Tritoechia. For this reason the cardinal process has only a short, curved
shaft which brings the myophore well beyond the level of the interarea. The
myophore is strongly lobate, with the central lobe elevated, and the lateral lobes
depressed. The brachiophores are mostly concealed by callus which spreads over
the structures of the umbonal chamber. For this reason it is not possible to
determine the presence or absence of the short and inconspicuous supporting
plates of the Tritoechiidae.

514 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

EREMOTOECHIA ALABAMENSIS Cooper, new species
Plate 78, A, figures 1-9

Shell of about medium size for the genus, transversely and broadly elliptical
in outline. Hinge narrower than the midwidth; cardinal extremities obtusely
angular, valves subequal in depth; sides rounded, maximum width at the middle.
Anterior margin broadly rounded, anterior commissure broadly uniplicate. Sur-
face multicostellate, costellae unequal in size, crowded, with striae narrower than
the width of the costellae ; about 12 costellae in 5 mm. at the anterior margin.

Pedicle valve gently convex in lateral profile and with the maximum con-
vexity at about the middle; anterior commissure broadly and gently convex, the
median region gently humped and with long, gentle lateral slopes. Umbo nar-
rowly convex, the convexity continued anteriorly for about two-thirds the length
but then merging with the flattened sulcate area. Median region somewhat swol-
len. Sulcus poorly defined, forming a broad, flattened or depressed area on the
median part of the anterior third. Lateral areas somewhat flattened and form-
ing long, gentle slopes to the cardinal extremities. Interarea long, flat, strongly
apsacline. Pseudodeltidium narrow ; foramen small.

Brachial valve fairly evenly but only moderately convex in lateral profile ; an-
terior profile broadly and fairly strongly convex. Umbonal region swollen;
median region from umbo to anterior margin swollen; sulcus shallow and nar-
row, originating at the beak and extending to the middle where it disappears in
the swelling anterior half which forms an ill-defined fold. Flanks full and with
short, steep slopes to the margins and cardinal extremities. Chilidial plates
prominent. Interior not known.

Measurements in mm.—Paratype (117060a), length 14.0, brachial length 13.7,
width 18.6, hinge width 12.1, thickness 8.7.

Types.—Holotype: 117060b ; figured paratype: 117060a; unfigured paratypes:
117060c-f.

Horizon and locality —Little Oak formation in Alabama: From a road cut on
U. S. Highway 31, 4 mile north of Pelham, Bessemer Iron District (15’)
Quadrangle.

Discussion.—This species is a fairly large one. Fragments in the collection
suggest a species comparable in size to E. cloudi. It is characterized by a short
but fairly strong brachial sulcus and a corresponding short, low, and narrow
fold on the opposite valve. In these respects it differs from E. cloudi and
E. silicica. The little known about the latter species indicates a shell somewhat
smaller than E. alabamensis.

EREMOTOECHIA CLOUDI Cooper, new species
Plate 77, B,C, figures 10-27
Shell moderately large, wider than long with the hinge equal to about three-

fifths the greatest width which is at the middle. Cardinal extremities obtusely
rounded. Lateral and anterior margins broadly rounded. Anterior commissure

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 515

broadly unisulcate. Surface multicostellate, with about 3 costellae occupying
I mm.

Pedicle valve gently convex in lateral profile, with the strongest convexity in
the posterior half; front half flattened. Anterior profile with the strongest con-
vexity at the center and the lateral slopes flattened and gently inclined. Umbonal
region somewhat swollen. Sulcus originating at the middle of the valve deepen-
ing and widening to the front margin, the sulcus producing a short, narrowly
rounded tongue. Anterolateral flanks bounding the sulcus flat; slopes to cardinal
extremities moderately steep, flat in profile.

Brachial valve evenly convex in lateral profile with the greatest convexity at
the umbo; moderately strongly convex in anterior profile. Umbo swollen, pro-
truding beyond the posterior hinge margin. Umbo depressed medially by a faint
and narrow sulcus which disappears at the middle where a low but distinct fold
originates and extends to the front margin. Flanks of shell steeply inclined.
Slopes to cardinal extremities steep; cardinal extremities deflected. Interarea
short, curved.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Fioletypeirysjaits dasa 19.0 18.5 22.4 16.6 12.5
Paratype (117062).. 20.3 17.5 23.0 16.0 11.8

Types.——Holotype: 117061a; figured paratypes: 117061b, 117062.

Horizon and locality—Arline formation in Tennessee: 4 mile southeast of
Friendsville, Concord (T.V.A. 138-SW) Quadrangle; 1 mile southeast of Fow-
lers Mill, 10 miles southeast of Loudon, Loudon (30’) Quadrangle.

Discussion.—This, like all known species of Eremotoechia, is a very rare one.
At the present writing only four specimens are known. These four specimens
indicate this to be the largest species in size and the one with the strongest orna-
mentation. The species is further characterized by the disproportionate depth
of the two valves, the brachial valve having the greater depth. The pedicle valve
is characterized by its generally gentle convexity; the brachial valve is distin-
guished by its rounded contours and the inconspicuous sulcus and the indefinite
anterior fold. This species differs from the other two known ones in its superior
size, lack of pedicle folding, and modest development of the brachial sulcus.

EREMOTOECHIA SILICICA Cooper, new species
Plate 50, B, figure 7; plate 99, H, figures 47-52; plate 186, F, figures 20-25

Smaller than the preceding species ; wider than long and having a subquadrate
to subrectangular outline. Valves subequal in depth, the brachial valve having a
slightly greater depth. Sides and anterior margin rounded; anterior commissure
broadly and gently uniplicate. Surface multicostellate ; costellae narrow and sepa-
rated by spaces greater than the width of the costellae ; about 3 costellae in 1 mm.
at the front margin.

Pedicle valve unevenly convex in lateral profile, the median portion somewhat

516 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

narrowly rounded, while the anterior portion is flattened and bent toward the
brachial valve and the posterior part is gently convex. Anterior profile form-
ing a fairly strong arch with convex middle and long, strongly sloping sides.
Umbonal region somewhat gently swollen; median region tumid, sloping steeply
in all directions except that toward the umbo; interarea strongly apsacline, mod-
erately long; foramen fairly large. Interior with small teeth having deep but
small fossettes ; dental plates well developed, divergent. Delthyrial cavity mod-
erately deep; diductor tracks wide and direct, separated by 2 parallel thin, low
ridges which form an adductor track.

Brachial valve in lateral profile moderately but unevenly convex, the greater
convexity in the posterior half and with the anterior half flattened. Anterior
profile strongly domed, the top of the dome somewhat flattened and the sides
with steep but short slopes. Median region inflated and with steep slopes laterally
and anteriorly ; umbonal region somewhat inflated and marked by a short and
shallow sulcus which disappears posterior to the middle; anteromedian region
somewhat swollen to obliterate the sulcus but not forming a distinct fold. Interior
with broad brachiophores and deep sockets ; cardinal process with bulbous myo-
phore; median ridge almost obsolete, and confined to the umbonal region.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype. 54 jehs: tues ? Ilia 14.2 9.4 3.6
Paratype (117065b)... 10.4 ? 12.3 8.7 GH)
is CIY7HO5C) s.00 t 8.9 12.2 88 3.5

Types.—Holotype: 117064a; figured paratypes: 117063, 117064b,c; 117065¢,
h,j,l.n; unfigured paratypes: 117064d,e, 117065a-f,i,k,m.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile south of
Pratt Ferry, Blocton (15’) Quadrangle.

Arline formation in Tennessee: About 100 yards south of the Negro Cemetery,
4 mile northeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Discussion—This species is based on adequate but possibly mostly young
specimens. It is the only material that yields a clue as to the nature of the pedicle
muscle field. The species as now defined differs from the other two known ones
in its finer costellae, more convex pedicle valve, and more strongly convex pro-
files. A somewhat crushed complete specimen from the Negro Cemetery in
Friendsville is assigned to this species because of its fine ornamentation.

Family CLITAMBONITIDAE Winchell and Schuchert, 1893
Clitambonitacea with radial ornamentation and spondylium simplex. With or
without lateral plates or pseudodeltidium.

Subfamily ATELELASMATINAE Cooper, new subfamily

Clitambonitidae with or without lateral plates.
This subfamily is proposed to include Apomatella and Atelelasma which are

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 517

more primitive (or possibly more specialized) members of the family in not
being provided with complete deltidial covers. Apomatella has an open del-
thyrium, and Afelelasma is distinguished by the presence of lateral plates that
grow obliquely toward the center of the delthyrium.

Absence of modifying plates over the delthyrium among the Clitambonitacea
may be a primitive character or it may be the reverse. Not enough is yet known
of the development of these forms to be sure which is the correct view. Among
the earliest of the Orthidae a deltidial cover is common, and its absence in the
later members suggests specialization. In the instance of Apomatella and Atele-
lasma, which are stratigraphically early members of the family, absence of the
covers may indicate primitive rather than specialized characters.

ATELELASMA Cooper, new genus

(Greek ateleo, imperfect; elasma, plate)

Planoconvex to unequally biconvex; hinge wide; interarea of pedicle valve
long and generally flat; delthyrium modified by lateral plates only. Anterior
commissure rectimarginate to gently sulcate; surface multicostellate, costellae
often swollen and hollow. Impunctate.

Pedicle interior with broad spondylium simplex supported by a short septum.
Vascula media usually strong and located on each side of the median septum.

Brachial valve interior with brachiophores in the form of thin, flat blades sup-
ported by swelling of the thick notothyrial platform. Cardinal process a simple
septum. Chilidium prominent. Median ridge thick, elevated and extending to
about the valve middle.

Genotype.—Atelelasma perfectum Cooper, new species.

Discussion.—This genus is characterized by its Vellamo-like form and usually
open delthyrium which is only modified by erect lateral plates. In this respect
it differs from all other members of the Clitambonitidae, which have a strong
pseudodeltidium with large subapical foramen. It differs from Apomatella in
having a higher organization, usually apsacline interarea, and a well-developed
chilidium which is absent from the European genus. Apomatella has rudimentary
lateral plates, but that genus is a more primitive one than Atelelasma.

Atelelasma differs from all members of the Estlandiidae in having an impunc-
tate shell.

Schuchert and Cooper (1932, pl. 7, figs. 5 and 11) figure a specimen of Atele-
lasma multicostum (Hudson) having an imperforate, short pseudospondylium
at the apex. This is the only specimen of the kind yet seen of this genus and the
only occurrence of such a plate known in it. None of the silicified specimens pre-
pared from the Arline formation showed any trace of such a plate. This pedicle
plate is low and lies just under the edges of the palintrope. Other specimens of
A. multicostatum are provided with lateral plates like those of the type species.
This plate may be a pedicle attachment lost from the other known specimens as
may be the case with certain spiriferoids, or it may be an atavistic occurrence,
the importance of which is not yet understood.

518 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ATELELASMA DECORTICATUM Cooper, new species
Plate 79, A, figures 1, 2; plate 82, J, figures 41, 42

Shell large, wider than long, hinge nearly equal in width to the width of the
shell. Cardinal extremities nearly a right angle. Lateral margins nearly straight ;
anterior margin broadly curved to subtruncate. Surface multicostellate but the
true nature of the costellae unknown.

Pedicle valve hemipyramidal ; gently convex in lateral profile; strongly convex
to subcarinate in anterior and posterior profiles. Median portion from beak to
anterior margin swollen into a low fold from which the flanks of the shell descend
steeply to the margins. Interarea moderately long and nearly procline. Del-
thyrium and lateral plates as usual in the genus.

Brachial valve nearly flat and with a shallow median sulcus extending from the
beak to the anterior margin. Anterolateral extremities depressed ; flanks bound-
ing sulcus slightly swollen.

Measurements in mm.—

Hinge
Length Width width Thickness
Holotype (pedicle valve)............. 16.2 23.5 21:7 6.6
Paratype (brachial valve r1o112b).... 18.4 22.6 ? ? ?

Types.—Holotype: 110112a; unfigured paratypes: r10112b-d; figured speci-
men: I17010.

Horizon and locality—Murat formation in Virginia: At Murat, Natural
Bridge (15’) Quadrangle, 14 miles west of Lexington; 2 miles northwest of
Lexington, Lexington (15’) Quadrangle.

Lincolnshire formation in Tennessee : On south side of the road opposite Shiloh
Church, northwest subquad., Pressmens Home (T.V.A. 171-NE) Quadrangle.

Lincolnshire (or Whistle Creek) formation in Virginia: At the top of the
ridge 1,000 feet north of the road on Buffalo Creek, 24 miles west of Murat,
Natural Bridge (15’) Quadrangle (specimen doubtfully placed in this species).

Lincolnshire formation (with Sowerbyites) in Virginia: At the spring 4 mile
east of the junction of Virginia Highways 608 and 652, 6 miles southeast of
Staunton, Augusta County.

Discussion.—As here defined this species may include some specimens that
will ultimately have to be excluded both on biological and on stratigraphic
grounds. The ornamentation of the specimens taken from the Murat limestone
is poorly preserved, while the exteriors of all the other specimens taken from
this horizon are not well preserved. The specimens from Buffalo Creek may
actually have been derived from the Whistle Creek limestone and may be referra-
ble to a totally different species when better specimens are found.

The examples taken from the Murat calcarenite are all large, generally larger
than most of the other described species except A. perfectum. It differs from
the latter in its more transverse form and less convex pedicle valve.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 519

ATELELASMA DORSOCONVEXUM Cooper, new species
Plate 80, G, figures 35-39; plate 82, M, figures 53-57

Of about medium size for the genus, length-width relation variable; cardinal
extremities nearly a right angle; sides gently rounded; anterior margin broadly
rounded. Surface multicostellate with about 2 costellae in a millimeter at the
front margin.

Pedicle valve hemipyramidal with a moderately long interarea inclined in a
catacline or strongly apsacline position. Lateral profile very slightly convex.
Interior with spondylium short and shallow, septum unusually short. Pallial
impressions not strongly impressed.

Brachial valve gently convex in lateral profile with the maximum convexity in
the posterior half. Median sulcus shallow and narrow but extending from the
umbo to the middle. Flanks gently convex. Interior with notothyrial platform
not strongly thickened; median ridge low and slender and extending nearly to
the middle ; cardinal process slender.

Measurements in mm.—

Brachial Hinge

Length length Width width
Holotype (pedicle valve) ............. 15.1 ? 17.7 15.8
Paratype (pedicle valve 11701Id)...... 15.8 ? 15.7 14.0
is (brachial valve 1170II1e)..... ? 14.2 17.9 14.0
x (cs a, SEETOLTE) conc P 12.3 16.9 13.1

Types.—Holotype: 117011h; figured paratypes: 110128b, 110129a-d, 11701Ib,
d-f; unfigured paratypes: 110128a,c,d, 11701 Ia,c,g,i,j.

Horizon and locality—Basal Athens formation in Tennessee: 24 miles south-
east of Riceville, Calhoun (T.V.A. 125-SW) Quadrangle; 600 feet S. 40° E.
of the railroad intersection with the highway 1 mile northeast of the courthouse
in Athens, Athens (T.V.A. 125-NE) Quadrangle.

Discussion—This species differs from A. perfectum in its smaller size, rela-
tively greater width to length, shallower and shorter spondylium, more strongly
sulcate and more convex brachial valve, and finely costellate exterior. Most of
the specimens come from leached limestone taken from the road and bank near
the intersection 24 miles southeast of Riceville. The specimens all occur in the
form of impressions of the interior and exterior in a rock that is difficult to
harden. Consequently, no replicas of the interior and exterior surfaces were
prepared. The fairly strongly convex brachial valve seems to be a very charac-
teristic feature of the species.

Pallial marks are fairly well displayed in the specimens figured, but those of
the pedicle valve are not as well developed as those of the opposite valve. The
pedicle vascula media are not long. This is a consequence, no doubt, of the very
short median septum supporting the spondylium. The brachial valve shows 2
wide pallial trunks originating at the inside anterior of the adductor field.

520 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ATELELASMA HOLSTONI (Hall and Clarke)
Orthis ? holstoni Safford in Hatt and CLarKE, Pal. New York, vol. 8, pt. 1, pp. 218, 340,
pl. 5A, figs. 35-37, 1892. For additional synonymy, see Basster, U. S. Nat. Mus. Bull. 92,
p. 892, 1915.

Type.—Holotype: New York State Mus. 7922/1.

Horizon and locality—Probably Hogskin member or Arline formation, vi-
cinity of Knoxville, Tenn.

Discussion.—The description of this species is in such general terms and the
stratigraphic horizon is so uncertain that it was not possible to identify any of
the species recorded herein with it. Hall and Clarke record the horizon and lo-
cality as “Glade limestone” (Lebanon) from near Nashville. This is certainly
a mistake, and the Bassler correction to the vicinity of Knoxville is probably
more nearly correct. The formation from which the specimen came is possibly
Arline but is more probably the Hogskin member.

ATELELASMA ? MULTICOSTUM (Hudson)
Plate 80, F, figures 26-34

Syntrophia multicosta Hupson, New York State Mus. Bull. 80, p. 285, pl. 5, figs. 8-15, 1903.

Clitambonites multicostus (Hudson) RayMonp, Ann. Carnegie Mus., vol. 7, p. 247, fig. 23;
pl. 36, figs. 10-14, 1911.

aff. Vellamo multicosta (Hudson) ScHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist.,
vol. 4, pt. 1, pl. 7, figs. 5, 8-11, 1932.

Types.—Figured hypotypes : 110117a-d; A.M.N.H. 25048/1,/3; Y.P.M. S359.

Horizon and locality—Crown Point formation in New York on Plattsburg
(15’) Quadrangle: Valcour Island, Plattsburg.

Same formation in Vermont: On Isle La Motte, Rouses Point (15’) Quad-
rangle.

Discussion—This little species was once found in abundance on Valcour
Island. Here the specimens were taken in the form of loose shells entirely free
of matrix. Specimens in the National Collection show a trace of the plates along
the sides of the delthyrium which are so characteristic of Atelelasma. A single
specimen in the Yale Peabody Museum collection (catalog number S359) shows
a small imperforate vestigial pseudodeltidium at the apex. This feature was not
seen on any other specimens of Atelelasma including the superb silicified speci-
mens from Friendsville. This pseudodeltidium is very much like that seen in
Kullervo punctata.

ATELELASMA OBSCURUM Cooper, new species
Plate 78, D, figures 21-31

Fairly large for the genus, wider than long and with the greatest width at the
hinge ; cardinal extremities acute; sides sloping medially ; anterior commissure
rectimarginate. Surface multicostellate, costellae narrowly rounded with inter-
spaces about equal in width to the width of the costellae; costellae numbering

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 521

about 7 in the space of 5 mm. at the front margin; a few costellae may be larger
than the surrounding ones.

Pedicle valve hemiconical in lateral profile; anterior profile broadly triangular.
Median region somewhat swollen; lateral areas with long, moderately steep
slopes; interarea catacline, long; plates bounding delthyrium moderately high.
Spondylium wide and shallow ; median septum moderately long.

Brachial valve nearly flat to gently convex in lateral profile; same in anterior
profile; umbo sulcate; sulcus shallow, widening to the front margin. Flanks
bounding sulcus gently swollen; cardinal extremities deflected slightly toward
the pedicle valve; chilidium small; notothyrial platform thick, cardinal process
thin ; median ridge reaching the middle ; pallial marks moderately well developed.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve) .......... 15.3 ? 22.0 23.5 5.8
Paratype (brachial valve 117012a).. ? 15.7 22.3 20.3 3.4?

Types——Holotype: 117012d; figured paratypes: 117012a-c,e,f,i; unfigured
paratypes : 117012g,h,j.

Horizon and locality.—Lincolnshire formation (Hogskin member) in Tennes-
see: 0.4 mile east-northeast of Red Hill, 4 miles west-southwest of Thorn Hill,
Avondale (T.V.A. 162-SW) Quadrangle; Republic Marble Quarry near Lut-
trell; south side of the school just north of the railroad crossing at Chesney,
Luttrell (T.V.A. 155-NW) Quadrangle.

Discussion.—This is not a common species. It is suggestive of dA. perfectum
in its ornamentation but differs in its proportions ; it is a much wider shell with
a flatter brachial valve. None of the localities has yet yielded a specimen with
both valves in contact.

ATELELASMA OKLAHOMENSE Cooper, new species
Plate 80, C, figures 12-19

Of about medium size for the genus, wider than long, with acute cardinal ex-
tremities and the hinge forming the widest part. Pedicle valve hemipyramidal
with a broad, flat, and procline interarea. Beak pointed and slightly upturned.
Brachial valve nearly flat with posterior portion extending well beyond the
pedicle interarea, exposing the cardinalia to view. Surface marked by strong
costellae separated by furrows narrower than the costellae. Costellae crossed by
strong concentric fila. About 9 costellae in the space of 9 mm. at the front margin.

Margin of delthyrium bordered by low plates set obliquely on the delthyrial
edge and decreasing to disappearance toward the beak. Spondylium fairly short.
Chilidium short and appearing as a broad arch over a thin cardinal process.

Measurements in mm.—Holotype, length 10.8, hinge width 16.3, length of
pedicle valve 8.9.

Types.—Holotype: 110124; figured paratype: 110125.

Horizon and locality —Bromide formation (Mountain Lake member—near top

522 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

in Multicostella convexa zone) in Carter County, Okla.: At Rock Crossing of
Hickory Creek, about center sec. 35, T. 5 S., R. 1 E., Criner Hills.

Bromide formation (Mountain Lake member—bed 16 of Decker) in Johnston
County, Okla.: On west branch of Sycamore Creek, sec. 22 and 27, T. 3 S.,
R. 4 E., 7 miles northwest of Ravia.

Discussion.—Up to the present time only two specimens have been collected.
This species is characterized by its strong costellae constituting an ornamenta-
tion unlike any other species of comparable size. Interrupted fila give the cos-
tellae a spiny appearance. This is suggestive of A. platys, but that is a much
smaller form.

ATELELASMA PERFECTUM Cooper, new species
Plate 70, B, C, figures 3-25; plate 126, H, figures 41-45

Shell large, having general appearance of Vellamo; unequally biconvex. Out-
line subquadrate. Lateral margins straight; anterior margin broadly curved to
subtruncate. Anterior commissure gently sulcate. Ornamentation variable, con-
sisting generally of costellae of unequal size. Stronger costellae extend from the
beak to the anterior margin and separate 1 or more finer costellae.

Pedicle valve hemipyramidal ; gently convex in lateral profile; more strongly
convex in anterior profile. Lateral slopes steep; steepest on the descent to the
cardinal extremities. Interarea long, strongly apsacline, gently curved or flat.
Delthyrium wide ; modified by lateral plates. Spondylium variable in form, low,
shallow ; narrow or broadly rounded at the front end. Median septum variable.

Brachial valve evenly and gently convex in lateral profile; median sulcus nar-
row, shallow, widening anteriorly, never conspicuous and becoming shallower at
the front. Flanks slightly swollen. Region about cardinal extremities slightly
depressed. Median ridge carinate, long. Cardinal process a simple ridge.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype "2 227 Seah, See 10.7 16.9 20.0 17.0 10.0
Paratype (110135m)........ 21.5 17.8 19.4 17.9 10.8
a (II OTA ever 15.3 14.1 16.5 16.3 10.4

Types.—Holotype: 110135g; figured paratypes: 110135d,f,h-l,n,p, 110136,
I17014a; unfigured paratypes: 110135a-c,e,m,o,q,r; figured specimen: 110132a.

Horizon and locality —Arline formation in Tennessee: Along wagon road in
glade, 4 mile southeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle ;
I mile northeast of Friendsville, Louisville (T.V.A. 138-SE) Quadrangle; 1
mile southeast of Fowlers Mill, 10 miles southeast of Loudon, Loudon County ;
Chapman Highway, 24 miles southeast of south end Henley Street Bridge, Knox-
ville, Knoxville (T.V.A. 147-NW) Quadrangle; McMullens, Meadow (T.V.A.
139-NW) Quadrangle.

Doubtfully in Whistle Creek formation in Virginia: Top of ridge 1,000 feet
north of the road on Buffalo Creek, 24 miles west of Murat, Natural Bridge
(15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 523

Discussion.—Atelelasma perfectum occurs in abundance in the beds contain-
ing Christiania at Friendsville and vicinity. The species is characterized by its
large size, the moderately convex pedicle valve, and the gently convex, rather
than flat, brachial valve. At Friendsville specimens are nicely silicified and can
be developed for interiors.

The species is also characterized by its somewhat square form which distin-
guishes it from A. decorticatum and A. obscurum.

ATELELASMA PLANUM Cooper, new species
Plate 80, D, figures 20-24

Shell small, plano- to concavo-convex ; hemipyramidal in outline. Hinge slightly
narrower than the greatest width. Cardinal extremities auriculate. Lateral mar-
gins nearly straight or sloping medially ; anterior margin broadly rounded. An-
terior commissure slightly sulcate. Surface multicostellate ; costellae appearing
in 4 generations by implantation. First generation forming strongest costellae
which stand above the others ; subsequent costellae tending to form fascicles with
2 or 3 generations in a fascicle.

Pedicle valve hemipyramidal; very gently convex in profile. Slopes to lateral
and anterior margins steep; interarea long, procline. Delthyrium wide.

Brachial valve flat or gently concave, with a deep median sulcus originating at
the umbo and extending to the front margin where it occupies about one-third
the width. Flanks bounding sulcus slightly convex; anterolateral extremities
slightly depressed.

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
Holotype . .calseca. wets 9.8 9.4 12.0 13.4 6.0
Paratype (110142a) .. 9.3 0.4 13.5 13.4 4.9

Types.—Holotype: 110142b; figured paratype: 110142a.

Horizon and locality—Benbolt formation (?) in Tennessee: 14 miles south-
east of Knoxville, Knoxville (T.V.A. 147-NW) Quadrangle.

Discussion.—This species is characterized by its small size and the nearly flat
brachial valve. In these respects it is like A.? multicostum and A. platys, but
it differs from both of them in details of its ornamentation. The costellae of
the former species are fine and even, whereas those of A. plana are differentiated
into coarser and finer ones. The ornamentation of A. platys is characterized
by spinelike projections along the costellae like those of A. oklahomense, but
they are absent from 4. plana.

ATELELASMA PLATYS Cooper, new species
Plate 50, G, figures 29-34

Shell small for the genus, wider than long with the hinge forming the widest
part; sides sloping toward the middle; anterior margin broadly rounded ; an-

524 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

terior commissure rectimarginate ; costellae broad in early generations ; 1 in I mm.
at the front margin; concentric fila strong.

Pedicle valve unevenly convex in lateral profile, the posterior half gently con-
vex, the anterior half depressed ; anterior profile broadly triangular ; median and
lateral regions moderately swollen. Interarea long, strongly apsacline; spondyl-
ium wide and shallow; median septum short.

Brachial valve unevenly convex in lateral profile, the posterior half gently con-
cave, the anterior half gently convex; anterior profile broadly and gently convex ;
sulcus originating at the beak and extending to the anterior margin, narrow and
moderately deep throughout its length. Umbo swollen; region anterior to umbo
concave ; anterolateral areas bounding sulcus moderately convex ; posterolateral
areas gently concave; notothyrial platform broad; cardinal process thin; median
ridge fairly long.

Measurements in mm.—Holotype, length 7.8, brachial length 7.3, width 10.6,
hinge width 9.8+, thickness ca. 5.7.

Types.—Holotype: 110144.

Horizon and locality—Lincolnshire formation (Hogskin member) in Tennes-
see: On the Maynardville Pike, 1.7 miles northeast of Hall Crossroad, Fountain
City (T.V.A. 146-SW) Quadrangle.

Discussion.—This species is small and has a nearly flat brachial valve, thus sug-
gesting such species as A. ? multicostum and A. oklahomense. It differs from
the former in having stronger and more distant costellae ; from the latter, which
it resembles in having spiny projections on the costellae, it differs in being a much
smaller shell and having a different outline. This species also differs from
A. variabile in outline and ornamentation.

ATELELASMA SULCATUM Cooper, new species
Plate 81, B, figures 7-13

Shell of about the usual size for the genus, wider than long; hinge slightly
wider than the midwidth; cardinal extremities slightly auriculate; sides nearly
straight, sloping slightly medially ; anterolateral extremities somewhat narrowly
rounded ; anterior margin nearly straight; anterior commissure rectimarginate ;
subequally costellate, about 10 costellae in 5 mm. at the front margin.

Pedicle valve with uneven lateral profile, the posterior half gently convex but
the anterior half flattened. Anterior profile broadly triangular, the sides of the
triangle with long, moderately steep slopes ; median region slightly swollen; sides
with long, gentle slopes; posterolateral region slightly sulcate just anterior to
the posterior margin; interarea long, slightly procline. Spondylium narrow and
moderately deep.

Brachial valve moderately convex in lateral profile; anterior profile broadly
and gently convex but median region sulcate ; median region swollen; umbo sul-
cate; sulcus narrow and shallow at the beak, widening and deepening anteriorly
to the middle of the valve, becoming less deep from there to the anterior margin.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 525

Flanks bounding sulcus swollen; posterolateral slopes short and steep. Median
ridge long ; notothyrial platform moderately wide.

Measurements in mm.—Holotype, length 13.5, brachial length 14.3, width 18.8,
hinge width 20.7, thickness 9.0.

Types.—Holotype: 117013.

Horizon and locality—Tulip Creek formation in Carter County, Okla.: 152
feet above the top of the basal sand on the first creek east of U.S. Highway 77,
SELNE4NES sec. 25, T. 2 S., R. 1 E., Carter County; 3 miles north-northeast
Gt oprmeer, SE4 sec. 32, IT. 2 5., R28,

Discussion—This is a very rare species; three specimens only have been
found. One complete, beautifully preserved specimen furnished the details of
the exterior. Two poorly preserved specimens showing the interior of both
valves yielded some idea of the interior. The species is characterized by large size,
rectangular outline, somewhat compressed form, convex brachial valve, and
fairly strong median sulcus. It differs from A. perfectwm in its proportions which
are more widely rectangular than subquadrate. It differs from A. obscurum in
the details of its ornamentation, which is much finer, and in its more convex
brachial valve. It is quite unlike A. oklahomense in outline, profile, and orna-
mentation.

ATELELASMA VARIABILE Cooper, new species
Plate 81, A, figures 1-6; plate 82, K, figures 43-47; plate 82, L, figures 48-52

Shell small for the genus, variable in outline, wider than long, nearly square
in large specimens with the hinge slightly wider than the midwidth; sides slop-
ing gently toward the middle ; anterior margin varying from broadly rounded to
gently emarginate. Anterior commissure rectimarginate. Costellae variable,
crowded, and separated by spaces narrower than the width of the costellae; 2
to 3 costellae occupy the space of 1 mm. at the anterior margin.

Pedicle valve gently convex in lateral profile ; anterior profile broadly triangu-
lar ; median region somewhat flattened ; lateral areas somewhat rounded ; postero-
lateral extremities deflected toward the brachial valve. Interarea long, strongly
apsacline to catacline.

Brachial valve faintly convex to flat in lateral profile; anterior profile very
slightly convex ; umbo sulcate; sulcus shallow, widening anteriorly to the front
margin, deepest in the median region and becoming shallower at the front mar-
gin. Flanks bounding sulcus moderately swollen; posterolateral extremities
depressed.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holoty petites Eeok. 6.8 7 fe} 0.7 9.9 5.0
Paratype (1170I5b).... 9.7 9.7 11.7 ? 6.0
cs (7I7pEse)y. 3, 5.0 6.3 8.5 ? 3.8

Types.—Holotype: 117015; figured paratype: 117015c; unfigured paratypes:
117015a,b; figured specimen: 117996.

526 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality—Lenoir formation in Tennessee: From calcarenites
under the Mosheim limestone, southwest side of cemetery behind the Quaker
Church, north corner of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—This is a rare species found only in a thin band of shale in the
calcarenites behind the Quaker Church in Friendsville. The few specimens ob-
tained show a variable form which is suggestive of the Crown Point species, A. ?
multicostum. It differs from that form in its stronger ornamentation and the
squarer form in the adult. Its outline and small size as well as its fairly uniform
ornamentation distinguish it from A. plana.

ATELELASMA sp. 1
Plate 8o, E, figure 25

Single pedicle valve placed under this name differs from A. perfectum by its
less convex profile, more uniform costellae, and shallower and broader spondyl-
ium. This species differs from A. decorticatum by its lesser depth and apsacline
interarea.

Measurements in mm.—110141, length 14, width 18, thickness 4.5.

Figured specumen.—t10141.

Horizon and locality.—Little Oak formation in Alabama: 4 mile east of Cobb
City=Cobb, Glencoe (74’) Quadrangle.

ATELELASMA sp. 2
Plate 81, C, figure 14

An interior of a pedicle and brachial valve were taken from the Botetourt
limestone on the roadside at the junction of Virginia Highways 114 and 311,
4 mile southwest of Catawba, Salem (15’) Quadrangle, Virginia. The interiors
resemble those of A. obscura, but nothing is known of the exterior ; consequently,
no further identification can be made.

Figured specimen.—117016.

Family KULLERVOIDAE Opik, 1934

Vellamo-like Clitambonitacea with spondylium triplex and hemisyrinx.

In Opik’s discussion of this family and genus it is stated that the shell sub-
stance of Kullervo is pseudopunctate. The specimens from the Southern Ap-
palachians described herein are silicified, and the true structure of the shell is
difficult to ascertain. However, silicified specimens of the Strophomenidae usually
reveal the papillose surface clearly. No evidence of pseudopunctae was seen in
the Appalachian specimens. It is thus possible that a parallel series of genera oc-
curs in the United States that duplicates the structure of Kullervo but is im-
punctate. The pseudopunctate Kullervo should be assigned to the Strophome-
noidea in the writer’s opinion, but in the absence of good collections for study
it seems best at present to leave the family in the Clitambonitacea.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 527

Genus KULLERVO Opik

Kullervo Orix, Acta et Comment. Univ. Tartu, ser. A, vol. 23, No. 3, p. 70, 1932; idem, ser. A,
vol, 26, No. 3, p. 162, 1934.

KULLERVO ORNATA Cooper, new species
Plate 80, A, figures 1-6

Shell small, wider than long with hemipyramidal pedicle valve. Surface multi-
costellate, the costellae crossed by elevated concentric plaits (lamellae). On the
brachial valve the posterolateral areas are conspicuously marked by the concen-
tric lines. Pedicle valve with broad shallow sulcus extending from beak to an-
terior margin; flanks rounded. Areas between flanks and posterior margin con-
cave. Spondylium broad and shallow with the characteristic median depression
flanked by narrow, elevated tracks. Median septum short.

Brachial valve slightly concave in the posterior half but slightly convex in the
anterior half. Sulcus widening rapidly from the beak to the anterior margin
where it occupies about one-third the width. Anterolateral flanks gently con-
vex; posterolateral areas flattened. Brachial interior with strong anteriorly
widening median ridge corresponding to the sulcus. Median ridge much elevated
and thickened anteriorly. Cardinalia much thickened.

Measurements in mm.—Holotype, length 2.3, width 3.8, hinge width 4.5, thick-
ness 2.6.

Types.—Holotype: 110150a; figured paratype: 110150b; unfigured paratype:
I1O150c.

Horizon and locality.—Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This species occurs with K. parva but is easily distinguished
by the differences in profile and ornamentation. The brachial valve of K. ornata
is concave in the posterior half but slightly convex in the anterior half and gives
the impression of a nearly flat valve, while the brachial valve of K. parva is
convex. The ornamentation of the latter consists of costellae of unequal size
but with subordinate concentric ornament. On the other hand K. ornata has
strong concentric ornamentation as well as costellae, and on the brachial valve
the concentric ornamentation dominates the posterolateral areas.

KULLERVO PARVA Cooper, new species
Plate 80, B, figures 7-11

Small, the largest specimen in the collection attaining a width of slightly more
than 4 inch. Wider than long with acute cardinal extremities in the adult, but
in young specimens the extremities are drawn into sharp ears. Pedicle valve hemi-
pyramidal in lateral profile with a fairly prominent median sulcus extending
from the beak to the anterior margin. Flanks bounding the sulcus narrowly
rounded and the area to the cardinal extremities slightly concave. Spondylium
large and shallow with a fairly deep median groove bordered by flat shelves on

528 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

either side. Median septum short. Pseudodeltidium appearing as a vestige of
that plate at the apex.

Brachial valve convex in lateral profile and broadly convex in anterior profile.
Sulcus deep, extending from the beak to the anterior margin and drawn into a
short tongue anteriorly in the direction of the pedicle valve. Flanks bounding
sulcus moderately convex with steep slopes to the posterolateral extremities but
with more gentle anterior slopes. Cardinalia ponderous. Brachiophores widely
divergent and supported by thick lateral swellings of callus. Cardinal process a
simple ridge.

Exterior of both valves marked by narrowly rounded costellae.

Measurements in mm.—Holotype (brachial valve), length 4.8, width 7.5.

Types.—Holotype: 110148a; figured paratypes: 110148b, 110149; unfigured
paratype: 110148c.

Horizon and locality.—Effna-Rich Valley formations in Virginia:. At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: 1.8 miles S. 4° W. of
Bethel Church, 5.9 miles east of Harrisonburg, Harrisonburg (15’) Quadrangle.

Discussion.—This species can be readily distinguished from K. ornata with
which it occurs by its convex brachial valve and predominantly radial orna-
mentation.

KULLERVO PUNCTATA Cooper, new species
Plate 90, G, figures 43-46

Shell fairly large for the genus, hinge forming the widest part; shell thick;
surface costellate and filate, the two of nearly equal strength so that the intersec-
tion produces deep pits, arranged in radial and concentric rows.

Pedicle valve moderately convex in profile; moderately full in median and
lateral regions. Interarea long ; spondylium wide and moderately deep, the char-
acteristic three tracks well developed. Median track deep; lateral tracks slightly
overhanging the median one. Median septum moderately long.

Brachial valve gently convex in both profiles; interior with ponderous noto-
thyrial platform, thick and long median ridge and long brachiophores.

Measurements in mm.—

Hinge

Length Midwidth width

Holotype (pedicle Walvey -cidieetie: sc ete 2 sane 6.7 ? 6.6
Paratype (brachial valve 117018b)............ She 5.8 ?

Types——Holotype: 117018a; figured paratypes: 117018b,c.

Horizon and locality —Botetourt ? formation in Virginia: On the south side
of the paved road 0.2 mile east of Strasburg Junction, Strasburg (15’) Quad-
rangle.

Discussion.—This species is larger than the other described forms from lower
Middle Ordovician rocks and is distinguished from them by the punctated
appearance of the exterior.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 529

KULLERVO SULCATA Cooper, new species
Plate 99, B, figures 15-18

Known from pedicle valve only. Minute, hemipyramidal as usual in the genus,
strongly suggestive of K. ornata but differing in having a much deeper median
sulcus, bounded by a strongly elevated costella. Outside each bounding costella
and inside the posterior margin is a fascicle of 3 or 4 costellae. Area between
fascicle and posterior margin concave and marked by strong, elevated concentric
lines. Spondylium broad and shallow; septum short.

Measurements in mm.—Holotype, length 2.4, hinge width 3.9.

Type.—Holotype: 117017.

Horizon and locality.— About 3 feet above the base of the Pratt Ferry forma-
tion in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Superfamily TrIPLESIACEA Cooper, 1944

Impunctate brachiopods having a flat pseudodeltidium, small apical foramen
in the pedicle valve, brachial valve with a long, forked cardinal process.

Family TRIPLESIIDAE Quenstedt, 1931

Characters same as those for the superfamily.

This family makes its first appearance in the Table Head series in the form
of Onychoplecia. The small size and generalized form of these little shells are
in keeping with the characters of an early stock. At the present time it is not
possible to suggest a possible progenitor. The family and superfamily characters
are all clearly developed in the earliest genus, but no indication is given by that
form of primitive characters that might relate it to brachiopods of the early
Ordovician.

ONYCHOPLECIA Cooper, new genus
(Greek onychos, claw; plekos, plaited)

Shell small, tear-shaped in outline, narrowly lenticular in profile; valves un-
equally convex, the brachial valve having the greater depth. Anterior commis-
sure uniplicate; fold of brachial valve usually short and in some species indis-
tinct. Surface marked by concentric lines of growth only. Shell substance fibrous,
impunctate,

Pedicle valve tear-shaped in outline, often with the beak elongated and slender ;
profile gently convex; delthyrium covered by a flat pseudodeltidium marked
along its center line by a more or less narrow fold; foramen apical, small; in-
terior marked by long, diverging dental plates; other details not known.

Brachial valve subcircular in outline and strongly convex in profile; chilidium
small, elongate, subtriangular ; cardinal process with stout shaft, forked distally,
the prongs of the fork bearing the myophores. Other details of the interior
unknown.

Genotype.—Onychoplecia brevirostris Cooper, new species.

530 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion.—Members of this genus are fairly common at a few places where
early Middle Ordovician rocks are exposed. Generally these specimens have
been placed in the genus Camerella. Examination of the pedicle beak region and
confirmation of the presence of divergent dental plates definitely rules out rela-
tionship to the camerellids. The entire structure of this genus places it as the
earliest known member of the Triplesiidae.

Triplesid characters appear in the pedicle valve in the form of the character-
istic pseudodeltidium. This is a nearly flat plate narrowly folded in the middle.
This narrow fold appears to be produced by anterior forward growth of the
pseudodeltidium over the small triangular chilidium that overlies the shaft of
the cardinal process. A few specimens only have revealed the presence of a
small foramen at the apex. This may be elongated along the umbo by resorption
as has been shown for other triplesids.

The brachial interior of most of the species described herein has been proved
to possess the forked cardinal process of the Triplesiidae. In addition to the
cardinal process several of the species revealed a small triangular chilidium like
that described for Onychotreta.

The appearance and characters of this genus place it closest to Triplesia, and
in common with that genus it is smooth and uniplicate. It differs from Triplesia
generally in its smaller size, usually disproportionate depth of valves, the brachial
valve being several times deeper than the pedicle valve, the extremely narrow
hinge, and the elongated beak. Early members of the genus suggest juveniles of
Triplesia.

Onychoplecia is first seen in the Table Head series of Newfoundland in a small,
strongly folded species. It is fairly common in Chazy rocks (Crown Point) of
New York. It is less common in Marmor rocks of Pennsylvania and Tennessee.
The youngest specimens known are from the Lower Bromide of Oklahoma and
the Sevier of East Tennessee, the latter from about the Benbolt level probably
being the younger.

ONYCHOPLECIA BREVIROSTRIS Cooper, new species
Plate 99, K, figures 65-70; plate 100, D, figures 15-22; plate 100, F, figures 28, 29

Shell small, but of fairly large size for the genus, tear-shaped in outline, com-
pressed lenticular in profile; sides rounded and with greatest shell-width located
anterior to the middle; front margin somewhat truncated. Anterior commissure
more or less broadly uniplicate. Surface marked by fine concentric lines of
growth.

Pedicle valve subtriangular in outline with the anterolateral margins strongly
rounded but the posterolateral margins nearly straight and making an angle of
85°. Lateral profile gently convex in the posterior two-thirds, moderately con-
vex in the anterior third. Anterior profile broadly and moderately convex. Sul-
cus broad and shallow, confined to the anterior third; tongue short, broadly
rounded. Median region and flanks swollen, interarea moderately long, pseudo-
deltidium with prominent and fairly wide elevated ridge.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 531

Brachial valve nearly circular in outline; lateral profile strongly convex and
with the greatest convexity at about the middle; anterior profile strongly con-
vex ; fold formed by a broad wave of the anterior commissure toward the brachial
valve; fold only slightly visible at the anterior third as a narrow, short
subcarinate elevation. Brachial interior with forked cardinal process.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
LOLOL VIDE. ait. state cietels ol Heelt so sieves 6.6 5.5 6.1 2.6 3.3
Paratype «(r7oSge)....-8hh.s.... 5.4 4.7 4.8 1.9 1.8

Types.—Holotype : 117089a ; figured paratypes : 117089b-e ; figured specimens :
118009a,b.

Horizon and locality —Lenoir formation in Tennessee: From the calcarenites
under the Mosheim calcilutite of the southwest side of the cemetery at Friends
Church, north corner of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.
Also, 3 feet above the Mosheim limestone south of the Friends Church, same
locality.

Discussion—This species is characterized by its fairly short beak, the wide
apical angle, which is almost a right angle, the modest convexity of the valves,
and the moderate folding of the anterior commissure. It thus differs from
O. longirostris and O. gracilis which have more attenuate pedicle valves. Ony-
choplecia obesa attains a much greater swelling of the brachial valve, and its
pedicle beak is more slender than that of the Friendsville species.

This little species is uncommon and hard to find. It occurs above and below
the “Mosheim” calcilutite. In the higher occurrences it appears in a coarse cal-
carenite and the valves are generally separated. The specimens from below the
“Mosheim” band were taken from a shale patch in the calcarenites.

ONYCHOPLECIA GRACILIS (Raymond)
Plate 100, C, figures 11-14

Triplecia gracilis RAYMOND, Bull. Amer. Paleont., vol. 3, p. 303, pl. 18, fig. 1, 1902.
Camerella longirostra RAYMoND (not Billings), Ann. Carnegie Mus., vol. 7, No. 2, p. 249,
pl. 36, figs. 29, 30, TOIT.

Fairly large for the genus, elongate tear-shaped in outline; sides rounded;
pedicle beak elongate with concave lateral margins ; anterior commissure strongly
uniplicate. Surface marked by strong, regular concentric lines.

Pedicle valve with elongated beak forming an apical angle of about 50°. Lat-
eral profile gently concave to flat in posterior part, moderately convex on body
of shell; anterior profile broadly and moderately convex. Median region swollen.
Sulcus short, narrow, deep, originating slightly anterior to the middle and oc-
cupying slightly less than half the width at the front margin. Posterolateral
slopes moderately steep; anterolateral slopes gentle. Interior with divergent
dental lamellae.

Brachial valve broadly oval in outline with the maximum width anterior to

532 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the middle; strongly convex in lateral profile with the maximum convexity at
about the middle; anterior profile strongly and broadly convex; umbonal and
median regions swollen; lateral slopes short and steep; fold short, narrowly
rounded, originating about 3 mm. anterior to the beak; anterolateral extremities
separated from anterior end of fold by oblique grooves, swollen and rounded.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (Carnegie Mus. 5457)..... 6.3 5.5 5.3 2.3 73 |
4g T2320 3A) bes aici sis Mets He sore, ae 4.7 4.0 4.0 1.4 2.2

Types—Figured hypotype: Carnegie Mus. 5457; measured hypotype:
1232938.

Horizon and locality—Crown Point formation in New York: On Valcour
Island; quarry 4 mile northeast of the Normal School, Plattsburg, Plattsburg
(15’) Quadrangle.

Same formation in Vermont: On Isle LaMotte, Rouses Point (15’) Quad-
rangle.

Discussion.—This species was assigned by Raymond in his 1911 revision of
the Chazyan brachiopods to O. longirostris Billings. The two species, however,
do not seem to be the same. The apical angle of O. gracilis indicates a species
with more attenuate beak than that of Billings’ species. Billings’ figures, how-
ever, indicate a specimen with exceedingly acuminate beak. Examination of the
type specimen, however, did not confirm this view. The pedicle sulcus of
O. gracilis is longer, narrower, and deeper than that of O. longirostris. Con-
sequently, the folds of the two species are different; that of Raymond’s species
is usually longer, narrower, and more prominent.

The New York and Vermont species is unlike O. obesa because of its less
convex brachial valve, wider and shallower sulcus, and the greater length and
narrowness of the fold. Raymond’s species is abundant in places in the Crown
Point formation of the Chazy group.

ONYCHOPLECIA KINDLEI Cooper, new species
Plate 100, B, figures 4-10

Shell small for the genus, subtriangular in otitline; sides gently rounded; an-
terolateral extremities narrowly rounded; anterior margin straight to medially
indented; apical angle about 70°. Anterior commissure narrowly uniplicate.
Surface smooth, but exfoliated specimens are marked by fine, distant radial
costellae.

Pedicle valve subtriangular in outline, lateral profile gently to strongly convex
with the maximum depth at about the middle; anterior profile moderately to
strongly and broadly convex with a median depression formed by the sulcus.
Umbo smooth and flat; sulcus originating on the umbo 4 to 1 mm. anterior to
the beak, shallow and narrow at the posterior of the shell but deepening and
widening anteriorly where it occupies about half the width; flanks bounding sul-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 533

cus swollen and with steep lateral slopes. Beak elongated, hinge narrow, pseudo-
deltidium marked by characteristic median ridge.

Brachial valve oval in outline with a moderately to strongly convex lateral
profile ; anterior profile broadly and moderately convex and marked medially by
a narrow fold; umbo swollen; median region inflated; fold narrowly rounded,
low, barely perceptible at the umbo but becoming prominent at about the middle ;
fold subcarinate in profile, separated from the swollen flanks by shallow, oblique
grooves.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FAEGEM EE Wc dttclattade cRIa tee bale aleve dine 00 a7 3.3 3.4 1.5 2.0
Paratype (pedicle valve 117092c)..... 5.4 ? 5.3 ? 2.6
rr (brachial valve 117092b).... ? 3.5 3.9 ? 2.0

Types.—Holotype: 117092a; figured paratypes: 117092b,d; unfigured para-
type: 117092c.

Horizon and locality—Table Head series in Newfoundland: At Table Point
Cove.

Discussion—This species is characterized by its small size, its long, deep, and
angular sulcus, and the prominent, long, narrowly rounded fold. This folding
distinguishes the species from all others now described.

ONYCHOPLECIA LONGIROSTRIS (Billings)
Plate 100, A, figures 1-3

Camarella longirostra BiLt1incs, Canadian Nat. Geol., vol. 4, p. 302, 1859; Geol. Canada,
p. 127, fig. 53, 1863.

Camarella ? longirostris Billings, TWENHOFEL and WHITING in Twenhofel, Geol. Soc. Amer.
Special Pap. 11, pp. 30, 53, pl. 7, figs. 25-27, 1938.

Shell of about usual size for the genus, tear-shaped in outline with an attenu-
ate beak; lateral margins rounded; apical angle about 70° ? Anterior commis-
sure broadly uniplicate. Surface smooth.

Pedicle valve moderately convex in lateral profile and with the maximum con-
vexity located just posterior to the sulcus; anterior profile broadly, moderately,
and evenly convex; umbonal region flattened; median region moderately swol-
len; sulcus confined to the anterior quarter, wide, shallow, and defined by a
narrow, oblique fold on each side; sulcus in width equal to about half the shell
width. Lateral regions somewhat swollen and with moderately steep slopes to
the margins. Divergent dental plates visible at beak.

Brachial valve subcircular in outline; lateral profile strongly convex ; anterior
profile strongly convex; maximum convexity at the middle where the valve is
strongly swollen; fold defined in the anterior quarter only, demarcated by shal-
low oblique grooves; fold rounded. Lateral slopes steep.

Measurements in mm.—Holotype, length 7.0 ?, brachial length 6.1, width 6.2,
hinge width 2.8, thickness 3.5.

Type.—Holotype: G.S.C. 1039.

534 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality—Mingan formation (about 25 feet above the base ac-
cording to Twenhofel and Whiting) on Quarry and Quin Islands, Mingan group,
St. Lawrence River, Quebec, Canada.

Discussion.—This species is characterized by its short fold, rotund and tumid
brachial valve, and moderately acute pedicle beak. It is not a common species,
according to reports, and is confined to the lower part of the Mingan formation
on two islands of the Mingan group. The distinctions between this species and
O. gracilis Raymond are stated under that species. This is the only described
species with which the Mingan form might be confused.

ONYCHOPLECIA MATUTINA Cooper, new species
Plate 121, F, figures 15-17

Shell small, suboval in outline, apical angle about 100°; sides rounded; an-
terior commissure uniplicate; surface smooth but where exfoliated, shell is
marked by radial lines as usual in the Triplesiidae.

Pedicle valve moderately convex in lateral profile; somewhat narrowly con-
vex in anterior profile; umbo somewhat narrowly swollen; median region in-
flated; sulcus originating at about the middle, short and deep and occupying
about half the width. Flanks bounding sulcus narrowly swollen and with steep
slopes.

Brachial valve moderately convex in anterior and lateral profile; umbonal
region swollen; fold originating just posterior to the middle, narrowly convex in
the middle and with moderately sloping sides. Flanks moderately inflated.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Ficlotype* Fa s.cd ote secs oa eit 57) ? 6.8 ? 12:5
Paratype \(1rT7oarb)ihas. ace cies ? 5.0 6.3 ? 0.8 ?

Types.—Holotype: 117940a; figured paratypes: 117941a,b.

Horizon and locality—Basal Everton formation in Arkansas: At the north-
west edge of Pindall, near the school, Yellville (30’) Quadrangle.

Jasper formation in Arkansas: Just northwest of Pindall, Yellville (30’)
Quadrangle.

Discussion.—This species is unlike any others of this genus described in its
transversely elliptical form, short, wide-angled beak, short deep sulcus and mod-
erately convex brachial valve. The species is of note because it is one of the few
fossils found in the Everton and Jasper formations.

ONYCHOPLECIA OBESA Cooper, new species
Plate 100, E, figures 23-27

Large for the genus, broadly oval in outline; sides rounded and anterior mar-
gin straight. Apical angle about 75°. Anterior commissure broadly and deeply
uniplicate in adults. Surface marked by concentric lines of growth and obscure
radial lines.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 535

Pedicle valve oval in outline with uneven lateral profile, the greatest depth in
the median region; anterior profile moderately convex; median region inflated ;
sulcus broad and shallow; tongue short and rounded.

Brachial valve broadly elliptical, width slightly greater than length; lateral
and anterior profile strongly convex ; valve deep and tumid ; umbonal and median
regions inflated and with precipitous slopes to the margins. Fold inconspicuous
and short, defined at the anterior quarter only ; plication of anterior commissure
deep.

Measurements in mm.—

Brachial
Length length Width Thickness
Holotype (brachial valve) ......... ? E 8.4 4.4
Paratype (pedicle valve) .......... 5.6 ? 5.3 7

Types.—Holotype: 117090b ; figured paratype: 117090a.

Horizon and locality—Row Park formation (Maclurites bed) in Pennsyl-
vania: About 175 feet above the “Mosheim” limestone at the base of the Row
Park formation, 4 to 4 mile east-northeast of the railroad cut, 24 miles southwest
of Marion, Chambersburg (15’) Quadrangle.

Same formation in Maryland: From the Maclurites bed in the ledge over-
looking the Potomac River in quarry at Pinesburg Station, Williamsport (15’)
Quadrangle.

Discussion.—This species is larger and unlike other described species of Ony-
choplecia. It is characterized by its fairly flattish pedicle valve, and extremely
swollen but well-rounded brachial valve. In the latter respect it differs from
Triplesia carinata from Pratt Ferry, Ala., which it resembles. The southern
species is characterized by its extreme depth, but it has a strong subcarinate fold.
The Pennsylvania species, on the other hand, has a tumid brachial valve but the
fold is inconspicuous on the body of the shell and may be seen only at the front
margin where it shows as a wave of the commissure. Differences of these sorts
in the brachial valves indicate that the pedicle valves, too, will be quite unlike.
The sulcus of O. obesa is short, wide, and shallow; that of Triplesia carinata, on
the other hand, is deep, wide, and has a strong median groove within the sulcus.

ONYCHOPLECIA TENUIS Cooper, new species
Plate 100, K, figure 50

About medium size for the genus, tear-shaped in outline with rounded sides
and attenuate beak forming an angle of slightly more than 70°. Anterior com-
missure perceptibly uniplicate with a suggestion of costation along the margin.
Surface smooth.

Pedicle valve gently convex in lateral profile with the maximum convexity in
the median region; anterior profile more convex than that of the lateral view,
broad and moderate. Umbonal region somewhat flattened; median region some-
what swollen; lateral slopes gentle. Sulcus in an incipient stage. Beak long;
pseudodeltidium with narrow longitudinal elevation.

536 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve oval in outline, gently convex in lateral and anterior profiles
but both profiles with a greater convexity than those of the pedicle valve. Um-
bonal and median regions gently inflated ; lateral slopes short, moderately steep.
Fold not defined.

Measurements in mm.—Holotype, length 5.1, brachial length 4.2, width 4.4,
hinge width 1.6, thickness 1.6.

Type.—Holotype: 117091.

Horizon and locality—Lower Bromide formation (Mountain Lake member)
in Oklahoma: On the McLish Ranch, sec. 24, T. 1 S., R. 7 E., Johnston County.

Discussion—This species is characterized by the modest convexity of its
valves. In this respect it is unlike any other described form. It is closest to
O. brevirostris but is flatter and has a more attenuated beak.

When the fold and sulcus of this species are studied with care, a suggestion
of anterior folding or costation can be seen. The costae are very indistinct and
can only be detected by examination of the commissure. Inasmuch as this is the
youngest species of this primitive genus yet seen, this anterior costation might
indicate a trend in its folding not seen in older forms. It might also indicate
that the specimen is actually a young form of a costellate triplesid such as
Oxoplecia. Members of that genus are abundant in parts of the Bromide forma-
tion of Oklahoma, but all the many specimens examined by the writer show
the costation originating on the beak. The specimen assigned to Onychoplecia
is quite smooth over the entire surface except at the commissure.

ONYCHOPLECIA sp. t
Plate 121, C, figures 9-12

Four specimens of Onychoplecia taken from high in the Sevier formation are
interesting because they represent the youngest specimens of this genus yet found
and because they indicate another undescribed species. Unfortunately, the speci-
mens are not adequate on which to base a species. The material consists of one
immature pedicle valve and two brachial valves which are probably mature.

The pedicle valve is 5.8 mm. long and 5.1 mm. wide at the widest part which
is anterior to the middle. The beak angle is about 70°, and the anterior is nar-
rowly rounded. In profile the maximum convexity is anterior to the middle.
A trace of a sulcus is to be seen at the anterior, but the shell is so young that this
adult character had not yet developed. A second pedicle valve is represented by
an imperfect impression which is clearly adult but has a long and deep sulcus.
The specimen has some camerellid features, but there is no way to prove the
true generic affinities. Although one of the brachial valves mentioned below also
has camerellid features, its interior details indicate that it is a triplesid.

Two brachial valves are present in the collection. One of these (117096b) has
a moderately prominent fold which is wrinkled by 3 costae. This is an unusual
feature for these triplesids, but the interior shows no median septum or other
camerellid features. The second brachial valve (117096d) is clearly a triplesid.
The shell is nearly smooth and has a subcarinate fold originating near the middle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 537

The shell is swollen on the flanks and in the median region just posterior to the
point where the fold originates. The specimen is unfortunately incomplete. Pos-
sibly two distinct species are represented by the material.

Figured specimens.—117096a-c ; unfigured specimen: 117096d.

Horizon and locality —Sevier formation (at the top of sandstone number 5)
in Tennessee: 0.28 mile northwest of Fourmile Church, Tallassee (T.V.A.
139-SE) Quadrangle.

Genus TRIPLESIA Hall, 1859

Triplesia Hatt, Pal. New York, vol. 3, p. 522, 1859—U.Lricu and Cooper, Journ. Paleont.,
vol. 10, No. 5, p. 345, 1936.

This genus is rare in most of the strata embraced by this book and from most
of the geographic areas. It is commonest in the Rockland (Napanee member)
of the Trenton group of New York where it has long been known. No authentic
specimens of the genus have to date been taken from the Appalachians north of
Tennessee, although it has been reported at a number of places. A well-marked
species, however, appears in the Lebanon limestone of the Central Basin of Ten-
nessee that had not hitherto been reported. This occurrence helps to emphasize
the post-Black River position of this formation. A triplesid of uncertain generic
affinities is known from the Little Oak limestone of Alabama.

Triplesia and Onychoplecia are closely related genera, and the former prob-
ably descended from the latter. Widening of the hinge and consequent shorten-
ing of the pedicle beak is about all that is necessary to produce Triplesia from
Onychoplecia.

TRIPLESIA CARINATA Cooper, new species

Plate 100,I, figures 41-43

Known chiefly from the brachial valve, but a probable immature pedicle valve
gives a clue to the generic character of the species. Large for the genus, wider
than long ; oval in outline ; sides narrowly rounded ; hinge narrow ; anterior some-
what trilobate. Anterior commissure deeply uniplicate with prominent brachial
fold and deep pedicle sulcus. Surface smooth, exfoliated areas marked by distant
costellae.

Pedicle valve tentatively defined as having gentle lateral profile, and broad,
gently convex anterior profile ; beak somewhat elongated ; sulcus originating near
the middle, deep and angular in section with a deep central groove; tongue ex-
tremely long and angular. Median region gently swollen. Sulcus bounded by
oblique, angular plicae. Foramen small, elongate; dental plates elongate and
narrowly divergent.

Brachial valve forming a rounded ellipse in outline, widest at about the middle;
lateral profile strongly convex and with greatest depth in the midregion; anterior
profile strongly domed and with a narrow median elevation. Umbonal region
narrow, swollen; median area inflated; fold originating on the umbo, strongly
elevated, subcarinate in section, demarcated by an oblique groove which divides
the narrowly swollen flanks from the steep sides of the fold. All slopes steep.

538 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial interior with short and narrowly triangular chilidium ; cardinal proc-
ess moderately long, slender, myophore forked, prongs moderately divergent.

Measurements in mm,—Holotype (brachial valve), brachial length 8.3, width
10.2, hinge width 4.6, thickness 7.1.

Types.—Holotype: 117095a; unfigured paratype: 117095b.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—Inasmuch as the true nature of the pedicle valve of this species
is somewhat uncertain, the species is based on the brachial valve as holotype.
This valve is distinctive and differs from all others known by its great depth,
inflated flanks and fold, and subcarinate and strongly elevated fold.

The species most suggestive of the Pratt Ferry one is Cliftonia grayae (David-
son) from the Stinchar limestone group, Craighead, Girvan District, Scotland.

TRIPLESIA SUBCARINATA Cooper, new species
Plate 100, H, figures 35-40

Shell small for the genus, syntrophoid in outline and profile. Valves unequally
convex, sides narrowly rounded and hinge narrower than the shell width. Smooth
exterior but exfoliated specimens with fine distant costellae.

Pedicle valve slightly convex in lateral profile with a central tongue bent almost
at right angles to the length. Sulcus originating at about the middle widening
rapidly to occupy about three-fourths the width at the place of geniculation of
the tongue. Flanks gently convex; slopes to margins moderately steep. Sulcus
and tongue marked by a narrow, shallow median groove.

Brachial valve moderately convex in lateral profile with the greatest convexity
at about the middle; steeply subcarinate in anterior profile. Beak small, umbo
narrowly rounded with a slight elevation continued anteriorly to join the fold
which originates at about the middle. Fold narrowly rounded with somewhat
swollen sides, separated from body of shell by narrow grooves. Flanks slightly
inflated, with steep lateral slopes. Cardinal process a long slender fork.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve) ........... 0.4 ? 11.0 8.0? 2.0?
Paratype (brachial valve 117094b)... ? 9.2 11.0 8.0? 5.9
Types.—Holotype: 117094a ; figured paratype: 117094b; unfigured paratypes:
117094c-e.
Horizon and locality.—Lebanon formation in Tennessee: At Columbia, Maury
County.

Discussion.—Triplesia subcarinata is suggestive of T. extans of the New York
Trenton but differs in having the fold and sulcus originating near the middle
of the valve instead of on the umbo as in the latter species. Besides this important
feature the Tennessee species is smaller in size and has a sharper fold. Further-
more, the young of 7. extans that correspond in size to 7. subcarinata are
not nearly so deep nor so rotund as the New York species.

PART | E CHAZYAN AND RELATED BRACHIOPODS—COOPER 539

TRIPLESIA sp. 1
Plate 121, D, figure 13

A single imperfect pedicle valve of this unusual genus was taken in the black
limestones of the Whitesburg formation at Bulls Gap. The specimen is 6.7 mm.
long and has the same distance as its maximum width. The sulcus originates at
about the valve middle and widens and deepens rapidly. The sulcus is bounded
by short, somewhat obliquely curved folds. The beak is moderately long and
shows two short divergent dental plates through the translucent shell. The
median region is moderately swollen.

Figured spectmen.—117097.

Horizon and locality.—Whitesburg formation in Tennessee: 14 miles west of
Bulls Gap, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Genus OXOPLECIA Wilson, 1913

Oxoplecia Witson, Victoria Mem. Mus. Bull., vol. 1, pp. 81-86, 1913.—ULricH and Cooper,
Journ. Paleont., vol. 10, No. 5, p. 337, 1936.

OXOPLECIA ABNORMIS Cooper, new species
Plate 104, G, figures 39-44

Shell small, transversely elliptical in outline with narrowly rounded lateral
margins and truncated front margin. Greatest width at about the middle; unipli-
cate. Surface costellate, with 2 costellae occupying the sulcus and 3 on the fold.
Flanks marked by 8 costellae produced by the bifurcation and implantation of 2
or 3 primary costellae on each side of the fold and sulcus.

Pedicle valve gently convex in lateral profile with the greatest curvature in the
umbonal region. Sulcus originating just anterior to the umbo and widening an-
teriorly to occupy about one-third the valve width at the front margin. Flanks
bounding sulcus gently convex; posterolateral slopes to cardinal extremities
steep. Interarea apsacline, moderately long and narrow.

Brachial valve strongly convex in lateral profile and with the greatest con-
vexity in the posterior half. Umbonal region full but not conspicuous. Fold origi-
nating just anterior to the umbo, low throughout its length. Flanks bounding
fold gently convex in profile, with moderate slopes to the margins.

Measurements in mm.—Holotype, length 8.8, brachial length 7.8, width 13.4,
hinge width 7.0?, thickness 5.8.

Type.—Holotype: 110842.

Horizon and locality—Effna formation in Virginia: I mile east of Tilson Mill,
16 miles northeast of Marion, Nebo (T.V.A. 223-NW) Quadrangle.

Discussion.—This species is best distinguished by its narrowly and trans-
versely elliptical outline which sets it off from any other species described herein.
The species occurs with Oxoplecia holstonensis but differs from that species in
ornamentation, development of fold and sulcus, and convexity of valves as well
as outline.

540 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

OXOPLECIA COSTELLATA Cooper, new species
Plate 138, B, figures 8, 9

Shell of about medium size for the genus, wider than long and with sides
rounded. Surface marked by closely crowded rounded costellae, 8 on the fold,
7 in the sulcus, and 18 on the flanks.

Pedicle valve gently convex in anterior and lateral profiles; sulcus broad and
shallow ; tongue moderately long and broadly rounded ; flanks flattened and with
gentle slopes to the sides. Brachial valve moderately convex in lateral profile and
fairly strongly arched in anterior profile. Fold originating just posterior to the
middle, moderately elevated and with costellae of the flanks crowded to its sides.

Measurements in mm.—Holotype, length 10.1+, brachial length 9.1, midwidth
12.3, hinge width 9.0, thickness 6.0.

Type.—Holotype: 117126.

Horizon and locality—Whistle Creek formation in Virginia: From a cut on
U. S. Highway 60, 100 yards southeast of Whistle Creek, 2 miles northwest of
Lexington, Lexington (15’) Quadrangle.

Discussion.—This species is characterized by its flattish pedicle valve and
closely crowded costellae. In these respects it suggests O. planiventra and
O. recta. It differs from the former in having only 6 costellae on the fold and a
much less convex brachial valve. It differs from the latter in having finer
costellae.

OXOPLECIA DEPRESSA Cooper, new species
Plate 100, J, figures 44-49

Shell small, transversely elliptical in outline and with rounded sides and gently
rounded anterior margin. Anterior commissure moderately uniplicate. Surface
marked by 9g costellae on the fold, 7 or 8 in the sulcus, and 16 costellae on the
flanks; costellae rounded and crowded, often bifurcated or intercalated at the
margin.

Pedicle valve gently convex, most convex just anterior to the umbo; anterior
profile broadly and faintly convex; umbonal region swollen; sulcus originating
just posterior to the middle, shallow throughout and forming a short, broadly
rounded tongue. Flanks bounding sulcus gently concave and with moderately
sloping surface. Interarea short, apsacline.

Brachial valve strongly convex in lateral profile and strongly domed in an-
terior profile; umbonal and median regions strongly swollen; flanks moderately
swollen and with steep sides. Fold inconspicuous, discernible only at the anterior
and merged with the flanks and swollen median region.

Measurements in mm.—Holotype, length 8.3, brachial length 7.7, midwidth
10.5?, hinge width 6.8, thickness 5.3.

Types.—Holotype: 117100b; unfigured paratype: 117100a.

Horizon and locality.—Effna formation in Virginia: 4 miles southwest of
Bland, Bland County.

Discussion.—This species is unlike any other described herein in the modest

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 541

development of the fold and sulcus. Its closely crowded ornamentation is sug-
gestive of O. costellata, but that species is more strongly ornamented and has
a strong fold and sulcus.

OXOPLECIA EIDSONENSIS Cooper, new species
Plate 104, B, figures 7-11; plate 104, F, figures 32-38

Shell of about medium size for the genus, transversely elliptical in outline, with
narrowly rounded lateral margins and broadly rounded anterior margin. Pedicle
valve fairly deep. Surface multicostellate with the fold occupied by 4 to 8 costellae
and the sulcus by 3 to 7 costellae. Flanks marked by 12 costellae. Intercalation
of costellae occurring just anterior to the umbo. Surface covered by concentric
fila, about 4 to the millimeter on the flanks.

Pedicle valve evenly and gently convex in lateral profile; anterior profile
broadly convex but depressed medially by the sulcus. Beak slightly incurved.
Sulcus originating just anterior to the umbo, about 24 mm. anterior to the end
of the beak; sulcus moderately deep and widening rapidly to the front margin
where it occupies about half the shell width. Costellae bounding sulcus stronger
than others on flanks ; flanks gently convex but with steep slopes to the margins.
Interarea apsacline; hinge equal to about half the valve width; deltidial ridge
strongly elevated. Dental plates widely divergent.

Brachial valve strongly convex in lateral profile with the maximum convexity
in the umbonal region ; anterior profile strongly convex and with a median ele-
vation formed by the fold. Umbo swollen; fold originating about 2 mm. anterior
to the beak, low, rising slightly anteriorly and never strongly elevated; flanks
inflated and with steep slopes.

Measurements in mm.—

Brachial Hinge f
Length length Width width Thickness
Pe Ee hia whos uci eer ae 5 13.0 11.9 15.9 10.1 10.6
PARAL PED tonics cians tive ecw sle s 11.7 10.6 137, 7.9 8.2

Types.—Holotype: 110847b; figured paratype: 110847a.

Horizon and locality.—Lincolnshire formation in Tennessee: On old pasture
road 4 mile northwest of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle.

Same formation in Virginia: 1 mile northeast of Jeff Gillespie’s house, 14.4
miles southwest of Tazewell, Tazewell County.

Discussion.—This species is characterized by a fairly strongly convex brachial
valve and a moderately convex pedicle valve, a fairly deep pedicle sulcus but
only a moderately elevated brachial fold. The species most closely resembles
Oxoplecia planiventra but has a more convex pedicle valve and more robust form.
Oxoplecia recta from the closely related Hogskin member of the Lincolnshire
formation resembles O. eidsonensis more remotely than O. planiventra. O.xo-
plecia eidsonensis is larger and more robust than the Hogskin species but it is
also proportionately wider and more strongly elliptical in outline.

542 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

OXOPLECIA FILOSA Cooper, new species
Plate 103, A, figures 1-12

Shell large, slightly wider than long, subcircular in outline; sides broadly
rounded; hinge narrow; anterior margin broadly rounded; uniplicate; valves
unequal in depth, the brachial valve usually considerably deeper ; surface costel-
late, costellae low and rounded, separated by spaces about equal in width to the
width of the costellae; costellae becoming broad and subdued on the anterior
margin; 12 costellae on the flanks; fold and sulcus with variable number from
5 to 8.

Pedicle valve unequally convex in lateral profile the greatest convexity located
in the posterior third ; anterior profile broadly and gently convex ; sulcus originat-
ing 4 to 5 mm. anterior to the beak, shallow in the median region, only moder-
ately deep at the margin where it occupies less than half the width. Sulcus
bounded on each side by a narrow plica consisting of 2 costellae somewhat more
elevated than those on the outside ; flanks gently convex ; slopes moderate. Inter-
area long, curved, moderately apsacline; beak moderately protruding. Tongue
long and narrow.

Brachial valve gently convex in lateral profile except for the umbo which is
inflated ; anterior profile strongly and broadly convex; fold originating about 5
to 6 mm. anterior to the beak, very low on the middle of the valve and not be-
coming more than moderately elevated at the front margin; flanks bounding
fold swollen and convex and with steep lateral slopes.

Measurements in mm.—

a

Brachial Hinge
Length length Width width Thickness
EOL PE woos vat Uae a ahs 20.5 a7, 21.6 13.1 Tr
Paratype’ +. .!0i9 sBaveecs vets 14.0 12.8 17.9 12.6 8.9

Types——Holotype: 1170992 ; figured paratype: 117099b.

Horizon and locality.—Bromide formation (Mountain Lake member) in Okla-
homa: Road cut on Oklahoma Highway 18, center NW} sec. 11, T.1S.,R.3 E,,
1.8 miles south of Sulphur, Murray County.

Discussion—This is one of the larger species of Oxoplecia which is orna-
mented by slender costellae. It thus resembles O. gouldi, O. nevadensis, and
O. multicostellata. Oxoplecia filosa differs from O. gouldi in its much rounder
outline, the length and width being nearly equal; the interarea is longer, so that
the beak is more elevated above the brachial umbo; the pedicle valve is less deep
than that valve in O. gouldi; the fold originates nearer the center of the brachial
valve than in O. gouldi, and the sulcus of the latter is deeper than that of O. filosa.

Oxoplecia nevadensis has a stronger fold and sulcus than O. filosa and its
valves are deeper, the outline is more transverse, and the pedicle beak is less erect.

Oxoplecia filosa differs from O. multicostella in its less prominent fold and
sulcus, the sulcus of the latter species originating far up on the umbo; it differs
in its more compressed form, less exposed pedicle interarea and more inflated
umbonal region.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 543

Oxoplecia planulata also has a compressed outline and thus suggests O. filosa,
but the compression is more exaggerated and it has a wider and more elevated
fold than the Oklahoma species.

OXOPLECIA GIBBOSA Cooper, new species

Plate 102, A, figures I-17

Shell a little below medium size for the genus, roundly elliptical in outline,
unequally biconvex in lateral profile. Lateral margins narrowly rounded; an-
terior margin truncated. Sulcus occupied by 2 to 3 costellae and the fold by 3
or 4. Flanks marked by about 6 costellae. Fila numbering 3 to 4 in a millimeter
near the middle of the valve.

Pedicle valve moderately convex in lateral profile and with prominent and
erect beak; anterior profile broadly and gently convex; umbonal region convex ;
sulcus originating slightly posterior to the middle, widening and deepening
rapidly to occupy about half the valve width at the front margin. Tongue long
and rounded. Flanks slightly convex to slightly concave in profile; lateral slopes
moderate. Hinge width equal to about half the valve width. Interarea short;
deltidial ridge low ; interarea gently to strongly apsacline.

Brachial valve half again as deep as the pedicle valve, strongly convex in lateral
profile with greatest convexity posterior to the middle. Beak prominent, over-
hanging hinge margin. Umbo swollen. Fold originating at place of maximum
curvature, low throughout its extent. Flanks gently convex with very steep
lateral slopes.

Measurements in mm,—

Brachial Hinge
Length length Width width Thickness
PaO VANE S| cok eine «ie! sina ages p'sm 0.0. 12.5 11.4 14.9 6.5 9.6
Pafatype (110655a) ......... 10.0 9.5 13.2 5.8 8.0
% CETOS5§c Ph OTP, 9.3 8.6 II.1 5.1 7.0

Types.—Holotype: 110860; figured paratypes: 110855a,c; unfigured paratype:
T10855b.

Horizon and locality—Ward Cove formation in Tennessee: At Inskip, E 2,
604, 600-700/N-596, 350 (military coordinates), Fountain City (T.V.A.
146-SW) Quadrangle; Hickey place, 2 miles southwest of Hall Crossroad,
Fountain City (T.V.A. 146-SW) Quadrangle; Evans Ferry, Howard Quarter
(T.V.A. 162-NW) Quadrangle; # mile southwest of Mount Eager Church,
Hogskin Valley, Powder Springs (T.V.A. 154-SW) Quadrangle; $ mile north
of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle.

Red Knobs formation in Tennessee: 1 mile north and 3 mile northwest of
Meadow Station, Meadow (T.V.A. 139-NW) Quadrangle, 14 miles east of
Friendsville, and 1 mile south of Louisville, Louisville (T.V.A. 138-SE) Quad-
rangle.

Base of “Ottosee’= Ward Cove horizon in Tennessee: At 1 mile southeast
of Whitehorn, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Little Oak formation in Alabama: At Hebron Church, 6 miles southwest of

544 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Leeds, Leeds (15’) Quadrangle; Ragland Cement Company Quarry, 3 miles
southeast of Ragland, St. Clair County.

Ward Cove formation in Virginia: At Rye Cove, Clinchport (T.V.A.
188-NW) Quadrangle.

Effna formation in Virginia: At McNutt Quarry 12 miles southwest of Bland,
Burkes Garden (15’) Quadrangle.

Discussion—O-xoplecia gibbosa as described herein is a variable species. The
variation may be due in part to preservation because some of the specimens are
loose silicified shells while others are enclosed in a limestone matrix. The costae
on the flanks vary from strong to almost obsolete ; consequently, some specimens
have a quite different appearance from others and the species is difficult to iden-
tify and distinguish from nearly related forms. Generally O. gibbosa is fairly
round in outline but has deep valves. It resembles O. holstonensis in outline but
is more strongly and less numerously costellated than that species. It is also a
more robust species than O. parva, a rare shell from the Benbolt formation.

Oxoplecia gibbosa differs from O. eidsonensis in having less numerous and
strong costellae and a rounder form. It differs from O. planiventra in its much
more robust and deep pedicle valve.

OXOPLECIA GLOBULARIS Cooper, new species
Plate 106, B, figures 6-11

Shell of about medium size for the genus, subcircular in outline with sides
broadly rounded and anterior margin nearly straight. Strongly inequivalve, the
brachial valve having the greater depth. Strongly uniplicate. Sulcus with 3 to
5 costellae; fold with 4 to 6 costellae. Flanks with about 9 costellae. Costellae
broad, separated by interspaces about equal to the costellae in width. Fila closely
crowded, 7 or 8 to the millimeter.

Pedicle valve moderately convex in lateral profile and broadly but gently con-
vex in anterior profile. Sulcus originating about 3 mm. anterior to the beak,
widening to the front margin where it occupies about two-thirds the width;
pedicle tongue long and subtruncate anteriorly ; flanks bounding sulcus narrow,
convex, and with steep slopes. Beak and interarea short, strongly curved.

Brachial valve strongly convex in lateral profile with the most convex part in
the umbonal region; anterior profile strongly arched and with precipitous sides.
Umbonal region smooth ; fold moderately elevated above the flanks ; flanks some-
what inflated.

Measurements in mm.—Holotype, length 13.9, brachial length 13.4, width 15.7,
hinge width 6.8, thickness 12.2.

Types.—Holotype: 117098b; figured paratype: 117098c; unfigured paratype:
117098.

Horizon and locality—Base of Martinsburg formation (part with Brogniar-
tella=Salona) in Virginia: On Virginia County Highway 617=910, 0.15 mile
north of Green Mount Church, Broadway (15’) Quadrangle.

Discussion—This species is characterized by its round outline and the great

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 545

depth of its valves, particularly the brachial valve. It is also strongly costellate
and has a deep sulcus and strong fold. It strongly simulates a robust form of
Parastrophina with which it occurs. These features distinguish the species from
any of the forms described herein, even O. gibbosa which is generally somewhat
smaller, more sparsely costellate, and with both valves less deep.

OXOPLECIA GOULDI Ulrich and Cooper
Plate 103, C, figures 17-29
Cliftonia gouldi DEcKER, Oklahoma Geol. Surv. Bull. 55, p. 42, pl. 13, fig. H (nomen nudum),
1931.
Cliftonia (Oxoplecia) gouldi Utricu and Cooper, Journ. Paleont., vol. 10, No. 5, p. 338,
pl. 50, figs. 8, 15, 18, 19, 23, 28, 32, 36, 1936.

Types.—Holotype: 91897; paratypes: 91898a,b; 91899; figured hypotypes:
110876, 118010.

Horizon and locality—Bromide formation (Pooleville member—O-oplecia
gouldi zone) in Carter County, Okla.: At Rock Crossing of Hickory Creek,
about center sec. 35, T.5 S., R. 1 E., Criner Hills ; NW4 sec. 26, T.5 S.,R.1 E.;
NE# sec. 1, T. 2 S., R. 2 W, 3 miles east of Pooleville, Carter County. Same
formation and member in Murray County, Okla.: 20 feet above the green shale
on Spring Creek, N$ sec. 17, T. 2 S., R. 1 W., Murray County.

OXOPLECIA HOLSTONENSIS Willard
Plate 90, J, figures 62-64; plate 100, G, figures 30-34; plate 1o1, D, figures 23-43

Oxoplecia holstonensis Wi1LLarD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 287, pl. 3, fig. 17, 1928.

Shell of about medium size for the genus, nearly circular or slightly elliptical
in outline, with well-rounded lateral extremities and truncated anterior margin.
Surface costellate with 2 to 5 costellae occupying the sulcus and 3 to 6 on the
fold. Costellae on flanks variable in number, generally about Io.

Pedicle valve most convex in the posterior half, flattened or gently convex in
the anterior half. Sulcus originating slightly posterior to the middle, moderately
deep, and occupying about half the width at the front of the valve. Tongue mod-
erately long. Flanks bounding sulcus gently convex; lateral slopes moderately
steep. Hinge width equal to or slightly less than half the shell width. Interarea
short.

Brachial valve very strongly convex in lateral and anterior profiles. Umbonal
region not prominently swollen; beak not extending beyond posterior margin.
Fold originating about one-third the length from the beak, only slightly elevated
above the flanks throughout its length. Flanks most convex near the fold and
with steep slopes to the margins.

Measurements in mm.— Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve)....... 10.5 ? 12.4 ? ?
Hypotype (123296a) .......... 9.0 8.1 10.3 6.8 6.5

us GEPGEOSD)) Gis. weiss 10.0 9.8 12.8 6.7 6.3

546 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: M.C.Z. 8632; figured hypotypes: 117102a,b, 117105b,
117106b-f, 117107, 117108; measured hypotype: 123296a.

Horizon and locality.—Effna formation in Virginia: At the McNutt Quarry,
12 miles southwest of Bland, Burkes Garden (15’) Quadrangle; Porterfield
Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle; 1
mile east of Tilson Mill, 16 miles northeast of Marion, Nebo (T.V.A. 223-NW)
Quadrangle.

Botetourt formation in Virginia: 1 to 2 miles northwest of Lexington, Lex-
ington (15’) Quadrangle; Cedar Grove Church, 14 miles southeast of Harrison-
burg, Harrisonburg (15’) Quadrangle; 4 miles east of Catawba, Salem (15’)
Quadrangle; junction Virginia Highways 721 and 724, 2 miles northwest of
Brownsburg, Lexington (15’) Quadrangle; 3 miles northeast of Blacksburg,
Blacksburg (15’) Quadrangle.

Basal Edinburg formation (Liberty Hall facies) in Virginia: On the boundary
of George Washington Forest, 1.8 miles S. 4° W. of Bethel Church, 5.9 miles due
east of Harrisonburg, Harrisonburg (15’) Quadrangle; 1 mile northwest of
Lexington, Lexington (15’) Quadrangle.

Whitesburg formation in Tennessee: Under the railroad bridge east of Bulls
Gap, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Red Knobs formation in Tennessee: 3 miles east of Knoxville.

Discussion—This species abundant in the Effna formation, is generally of
small size and delicately costellate. It resembles O. gibbosa in form but is more
delicately ornamentated and has less deep valves. It differs from O. parva in
having a deeper brachial valve and finer ornamentation. Oxoplecia monitorensis
is larger, has a wider sulcus, stronger costellae, and a more transverse outline.

Oxoplecia holstonensis, like O. gibbosa, has variable ornamentation. This
seems to be a matter of preservation, but it is difficult to be certain about the
point. Some specimens appear to be nearly smooth, but the costellae are usually
perceptible. In other specimens the costellae are well developed and strong, and
the entire surface is covered by fila. The fact that fila are not visible on the
smoother shells suggests that the ornamentation was worn away. This fact is
confirmed by the common occurrence of this species in calcarenite matrix or
lime-sands. This is an environment of rapidly moving water which would abrade
the shell against the lime sand particles.

OXOPLECIA MAGNAPLICATA Cooper, new species
Plate 108, I, figures 43-48

Large for the genus; outline rectangular with narrowly rounded cardinal ex-
tremities, gently rounded sides, and somewhat narrowly rounded anterolateral
extremities ; anterior margin straight. Hinge wide; strongly uniplicate; strongly
costellate. Costellae irregular, thick and rounded, 6 to g on the flanks, 4 on the
fold, 3 in the sulcus on the type, but with anterior intercalations more may be
counted on other specimens.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 547

Pedicle valve evenly and gently convex in lateral profile; anterior broadly and
gently convex. Umbo narrowly convex, small; sulcus originating 2 to 24 mm.
anterior to the beak, deepening rapidly to the front margin where it occupies
less than half the shell width. Sulcus bounded by a prominent elevated plication
occupied by 2 or more costellae; flanks gently concave. Interarea long, moder-
ately apsacline.

Brachial valve gently convex in lateral profile with the umbo swollen but not
strongly protruberant ; anterior profile broadly and gently convex. Umbo swollen
and small; fold originating on the anterior side of the umbo, elevating rapidly
toward the front margin where it is high and with precipitous sides. Sulci at
base of folds moderately deep and prominent, producing narrow lobes. Flanks
gently swollen; posterolateral extremities somewhat flattened to perceptibly
concave.

Measurements in mm.—Holotype, length 15.5, brachial length 13.9, width 21.2,
hinge width 15.9, thickness 9.6.

Type.—Holotype: 117109.

Horizon and locality —Shippensburg formation (Pinesburg member—Echino-
sphaerites zone) in Maryland: Road cut on U. S. Highway 40 at Wilson on the
west side of Conococheague Creek, 7 miles west of Hagerstown, Williamsport
(15’) Quadrangle.

Discussion.—This species may be recognized by the strength of the costellae,
the fairly narrow and elevated fold, and deep sulcus. The species is broadly
shouldered but its profile somewhat compressed. It differs from O. simulatrix
(Bassler), which has a high fold, in the greater strength of the costellae and in
the less rotund profile. Oxoplecia pennsylvanica is strongly costellate and ap-
proximately the same size as O. magnaplicata, but it has more convex valves,
lesser width, and a deeper sulcus.

OXOPLECIA MARMORATA Cooper, new species
Plate 103, B, figures 13-16

Shell of small to medium size for the genus, wider than long and with a broadly
elliptical outline ; sides narrowly rounded ; anterior margin broadly rounded ; sur-
face strongly and completely costellate; numerous costellae bifurcating near the
front margin; flanks with as many as 15 costellae; sulcus with 3 to 6 and fold
with 4 to 7 costellae.

Pedicle valve moderately convex in lateral profile and broadly and gently con-
vex in anterior profile ; umbo narrow; sulcus originating 2 to 3 mm. anterior to
the beak, wide and shallow, and occupying at least half the width. Flanks flat
and with gentle slopes.

Brachial valve moderately convex in lateral profile but fairly strongly convex
in anterior view; umbo swollen; fold broad and gently rounded, not strongly
separated from the flanks, only gently elevated. Flanks inflated and with steep
lateral slopes.

548 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve) ........... 8.0 ? 10.0 6.5 ? 1.8
Paratype ( “ (on SITIO ahs ns ? 10.4 7.52 1.2
a (brachial valve I171I0c)... ? 8.0 10.2 7.6? 3.0
iy Ga ee TZ LION) ss. of 8.2 13.1 ? 3.0

Types.—Holotype: 117110a; figured paratypes: 117110b,c,e; unfigured para-
type: 117110d.

Horizon and locality—Red Knobs formation in Tennessee: 1 mile south of
Louisville, Louisville (T.V.A. 138-SE) Quadrangle.

Discussion.—This is a small species so far known only from a “marble’’ facies.
It reminds one somewhat of O. holstonensis but is more strongly costellate and
with a wider outline. It is somewhat suggestive of O. eidsonensis in the exterior
markings, but that species is larger and more robust with a strongly convex
brachial valve. The costellae also suggest O. recta, but that species has a much
flatter pedicle valve and a more strongly convex brachial valve.

OXOPLECIA MONITORENSIS Cooper, new species
Plate 102, D, figures 33-37

Shell of about medium size for the genus, wider than long, with a narrow
hinge and somewhat narrowly rounded sides. Front margin truncated. Tongue
short and broadly rounded. From 8 to Io costae on the flanks, and 6 in the
sulcus.

Pedicle valve gently convex in lateral profile; broadly and gently convex in
anterior profile; umbo somewhat swollen. Sulcus originating 2 mm. anterior to
the beak, wide and shallow, occupying about half the width. Flanks bounding
sulcus slightly convex and with moderately steep posterolateral slopes. Inter-
area short, curved, apsacline; beak short.

Brachial valve moderately convex in lateral profile but with a swollen umbo;
anterior profile strongly arched. Fold poorly defined on the median region, be-
coming elevated moderately at the front. Flanks moderately swollen and with
steep slopes to the margins.

Measurements in mm.—Holotype, length 11.6, brachial length 11.7, width 15.0,
hinge width 9.7, thickness 8.0.

Types.—Holotype: 117111a; unfigured paratypes: 11711Ib,c.

Horizon and locality —Yellow limestone above the 25-foot bed of sandstone
marking base of Eureka group, in Nevada: On the saddle just north of hill 8167,
Martins Ridge, Monitor Range, Roberts Mountains (1°) Quadrangle.

Discussion.—This is a small rotund type of Oxoplecia suggestive of O. hol-
stonensis and O. parva. It is, however, slightly larger than both of these species.
It is also more strongly costellate than O. holstonensis and has a much less con-
vex brachial valve, a much deeper sulcus, and a somewhat wider fold. The cos-
tellae of O. parva are somewhat stronger than those of the Nevada species, and
its brachial valve is less strongly umbonate but is more convex.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 549

OXOPLECIA MULTICOSTELLATA Cooper, new species
Plate 105, A, figures 1-27; plate 106, E, figures 25, 26

Shell large, roundly elliptical in outline; sides broadly rounded; anterior mar-
gin trilobate; valves unequally convex, the brachial valve having the greater
depth; hinge narrow; uniplicate; multicostellate ; flanks with 14 to 19 costellae ;
fold with 8 to 11 and sulcus with 7 to 10 costellae. Surface strongly filose, fila
distant on body of shell, closely crowded at the margins.

Pedicle valve with unevenly convex lateral profile, the posterior half having
the greater convexity and the anterior half somewhat flattened. Anterior profile
broadly and moderately convex. Umbo strongly convex; sulcus originating 5
to 6 mm. anterior to the beak, shallow and poorly defined in the median region
but deepening toward the front to attain about half the shell width. Sulcus
bounded by a narrow plica in its anterior third; flanks bounding sulcus flat to
gently concave and with gentle slopes. Interarea curved, apsacline.

Brachial valve with greatest curvature in the umbonal region which is strongly
arched and is almost level with the pedicle beak ; anterior profile strongly arched,
but with only moderately steep slopes. Umbo swollen; median region swollen.
Fold originating 6 to 7 mm. anterior to the beak, low and inconspicuous on
the median part but fairly strongly elevated in the anterior region where it forms
a lobate projection. Flanks somewhat swollen and steep posterolateral slopes.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holtotypiess catiic: byes oa sesiae 19.9 19.2 23.0 12.4 12.9
Paratype) (1iG IAA). cui 3.d sane 18.9 18.5 24.7 11.6 14.1
Me GRETPDTC D2 shane 18.5 177 21.3 12.8 11.9

Types.—Holotype: 111790; figured paratypes : 111791a,d-f, 117112, 117113a-c,
e,h,j, II7I14a, 123334; unfigured paratypes: 111791Ib-c,g-i, 117113d,f,g,i,k-p,
117114b.

Horizon and locality.—Benbolt formation in Virginia: 0.2 mile south of the
middle fork of Moccasin Creek, 14 miles south of Hansonville, Hansonville
(T.V.A. 205-SW) Quadrangle ; west slope of the hill $ mile east of Cedar Point
School, Hilton (T.V.A. 197-NW) Quadrangle; on Virginia Highway 74, 0.2
mile southwest of New Bethel Church, 4 mile east of the junction with U. S.
Highway 54, Hilton (T.V.A. 197-NW) Quadrangle; 4 mile southeast of Rich-
patch, Eagle Rock (15’) Quadrangle; just east of meridian 17°30’ east of Moc-
casin Creek, north edge of Mendota (T.V.A. 197-NE) Quadrangle; Virginia
State Highway 80, 4 mile south of Rockdell, Elk Garden (T.V.A. 212-NW)
Quadrangle; Fugates Hill, 2 miles N. 45° W. of Mendota, Bristol (30’) Quad-
rangle ; 4 mile northeast of Speers Ferry, Clinchport (T.V.A. 188-NW) Quad-
rangle; Green Valley, 3 miles south-southwest of Lebanon, Brumley (T.V.A.
205-SE) Quadrangle; north side of U. S. Highway 19, 12 miles southeast of
Hansonville Post Office, Brumley (T.V.A. 205-SE) Quadrangle.

Benbolt formation in Tennessee: On the north side of the road 1.1 miles
northeast of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

550 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Chatham Hill formation in Virginia: 1.2 miles S. 31° E. of Sharon Springs,
Burkes Garden (15’) Quadrangle; Grayson Farm, 4 miles southwest of Bland,
Bland County; on Virginia Highway 113, Marion-Chatham Hill Road, 6 miles
north of Marion, Chatham Hill (T.V.A. 218-NE) Quadrangle; 150 feet above
the black beds in Porterfield Quarry, 5 miles east of Saltville, Maccrady (T.V.A.
218-NW) Quadrangle.

Sevier shale in Tennessee: 4+ mile along the wagon road northwest of Bulls
Gap, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Edinburg formation (Cyrtonotella bed) in Virginia: Along Tumbling Run
14 miles southwest of Strasburg, Strasburg (15’) Quadrangle; ravine at switch
s to 4 mile east of Strasburg Junction, Strasburg (15’) Quadrangle; Colliers
Creek, $ mile north of the junction of Virginia Highways 251 and 612, west-
southwest of Lexington, Rockbridge County ; Hiatt Run, 200 yards east of U. S.
Highway 11, 3 miles north of Winchester, Winchester (15’) Quadrangle.

Discussion.—This species is characterized by its large size and its numerous
fine costellae. It attains the largest size of any species occurring in the Appa-
lachian Valley. This species is quite suggestive of O. gouldi Ulrich and Cooper,
but it does not attain the size of the largest specimens of the Oklahoma species.
It is also somewhat more convex on the brachial side, has a narrower and more
elevated fold, and is more umbonate in the brachial valve. The pedicle beak of
O. gouldi is more incurved than that of O. multicostellata, and the ornamenta-
tion is somewhat finer.

Oxoplecia multicostellata is similar to O. nevadensis but differs in its some-
what finer costellae, its somewhat larger proportions and more rounded outline.
It has a more inflated umbonal region than the Nevada form and a less erect
pedicle beak. Ovoplecia simulatrix is another large species with which O. multi-
costellata might be confused, but it has different proportions, being a wider shell,
and also is more strongly costellate.

OXOPLECIA NEVADENSIS Cooper, new species
Plate 102, E, figures 38-49

Large for the genus, transversely and broadly elliptical in outline; sides some-
what narrowly rounded ; anterior margin nearly straight; costellate ; sulcus with
5 to 6 costellae, fold with 6 to 7, and flanks with 11 to 12. Intercalations irregular.

Pedicle valve moderately convex in lateral profile and with the posterior por-
tion somewhat swollen; anterior profile gently convex. Umbo smooth, sulcus
originating abruptly at the anterior side of the umbo about 4 mm. anterior to the
beak ; sulcus deep and narrow, occupying about one-third to one-half the width
at the front margin; flanks flat to gently convex and with moderate slopes. Inter-
area long, curved, apsacline.

Brachial valve moderately convex in lateral profile and with moderately swol-
len umbo ; anterior profile strongly convex. Fold originating on the umbo, fairly
strongly elevated to the anterior margin and with abrupt sides; flanks moder-
ately swollen and with moderately steep slopes.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 551

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EIGLORY Pel secstteaitiercieri ses ss 16.7 15.3 21.8 16.9 10.8
Paratype; shes isi. besa 15.7 15.2 20.0 13.0 11.7

Types.—Holotype: 117115a; figured paratype: 117115b.

Horizon and locality —Eureka group (upper part of dark gray shale under the
Eureka quartzite) in Nevada: On the north-facing nose of hill 8167 on Martins
Ridge, Monitor Range, Roberts Mountains (1°) Quadrangle.

Discussion—This is the largest of the species so far found in the Roberts
Mountains area. It is characterized by moderately strong costellae, a moderately
widely elliptical outline, and fairly strongly elevated fold and deep sulcus. Com-
parison with O. multicostellata of the Appalachians is made under the descrip-
tion of that species. The Nevada form is suggestive of O. simulatrix and occupies
a similar stratigraphic niche. It differs from that species, however, in having a
narrower fold and sulcus, and finer costellae.

OXOPLECIA OCCIDENTALIS (Butts)
Plate 101, C, figures 16-22

Cliftonia occidentalis Burts, Alabama Geol. Surv., Special Rep. 14, p. 126, pl. 31, figs. 21, 22,
1926.

The type lot consists of three specimens, one of which (71529c) is a young
distorted pedicle valve too poor for description. The remaining two are a young
pedicle valve and an adult brachial valve. The former is nearly circular in out-
line but with the width slightly greater than the length. The sulcus originates
slightly more than one-third the length anterior to the beak, is shallow through-
out its length. At the front margin the sulcus occupies about one-third the width
of the valve. Flanks flattened, with moderately steep slopes to the margins. Um-
bonal region strongly convex in profile with strongly incurved beak. Sulcus with
5 costellae, flanks with 14 costellae.

Brachial valve slightly wider than long, gently convex in lateral profile but
with a narrowly convex umbo. Fold originating just anterior to the umbo,
slightly elevated at the front margin, and occupied by 7 costellae. Flanks con-
vex, with steep slopes to form a narrowly rounded shell in anterior profile.
Flanks with 14 costellae. Beak low, not protruding beyond the posterior margin.

Measurements in mm.—

Length Width Thickness
Lectotype (brachial valve)................. 16.0 17.2 6.6
Paratype (pedicle valve 71529b)............ 12.5 14.6 3.9

Types.—Lectotype: 71529a; paratypes: 71529b,c; figured hypotypes:
117116a,b.

Horizon and locality.—The published locality of this species is “Basal Chicka-
mauga limestone, probably Ridley horizon, old quarry half a mile northeast of
Gate City,” Ala. This is evidently an error because a label in Dr. Butts’ hand-
writing with other Alabama specimens reads “14 miles northwest of Swansea

552 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

(Ireland).” The horizon of these specimens was referred to the Black River by
Ulrich in his report on fossils collected for the Birmingham folio. It is probable
that this last locality, too, is an error.

The type specimens of O. occidentalis are indentical with ones from Oklahoma.
Not only are the specimens identical with the Oklahoma forms, but the matrix
is like that of parts of the Bromide limestone. The resemblance is so strong that
it led Ulrich to pencil a note on the type label, as follows: “Probably Black
River age and not Ridley. See small Hallina-like brachiopod. This and the Clif-
tonia probably same as the Oklahoma Criner species.” Oklahoma specimens,
therefore, evidently were inadvertently labeled from Gate City, Ala.

The specimens herein illustrated were taken 149 feet below the top of the
Bromide formation (Pooleville member?) in Oklahoma: In the section 4 mile
west of U. S. Highway 77, 34 miles north of Springer, Carter County; another
lot of the same type of material was collected by C. A. Reeds in the section along
Spring Creek, SW4 sec. 6, T. 2 S., R. 1 W., east of Pooleville, Murray County,
and was taken from the heavy ledge in the creek above the 5th sandstone.

Discussion.—The species under discussion is represented by poorly preserved
specimens which were broken from matrix and are therefore so exfoliated that
details of the ornamentation are obscure. All the specimens despite this are well
rounded in outline. In this respect they are very different from O. gouldi. They
are more rounded than the young of O. gouldi and have more convex valves than
specimens of O. gouldi of comparable size. No other species is quite like this one.

OXOPLECIA PARVA Cooper, new species
Plate 102, B, figures 18-24; plate 106, C, figures 12-16

Shell small for the genus, roundly elliptical in outline with the lateral margins
broadly rounded and the anterior margin nearly straight; costellate, costellae
variable, strong to subdued, often absent on parts of the shell; 8 on the flanks at
the front margin. Fold with 4 or 5, and the sulcus usually with the same
variation.

Pedicle valve unevenly convex, with the maximum convexity just anterior to
the umbo; anterior profile broadly but faintly convex ; sulcus originating on the
anterior side of the umbo about 4 mm. anterior to the beak; sulcus deepening
rapidly anteriorly to occupy slightly more than half the shell width at the front
margin; flanks bounding the sulcus nearly flat; slopes gentle. Hinge narrow,
interarea short.

Brachial valve strongly convex in lateral profile and with the most convexity
in the umbonal region; anterior profile strongly arched and with long, steep
lateral slopes. Umbo smooth and swollen; fold originating slightly posterior to
the middle, fairly strongly elevated anteriorly. Flanks swollen and convex.

Measurements in mm.—Holotype, length 11.0, brachial length 10.3, width 12.3,
hinge width 7.3?, thickness 7.6.

Types.—Holotype: 117118; figured paratypes: 117117a,b; unfigured para-
type; I17117¢.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 553

Horizon and locality—Benbolt formation in Virginia: On east bank of a sink-
hole 300 feet south of Lakeview Church on Virginia Highway 71, Moll Creek
(T.V.A. 196-SE) Quadrangle; 0.2 mile south of the middle fork of Moccasin
Creek, 14 miles south of Hansonville, Hansonville (T.V.A. 205-SW) Quad-
rangle.

Discussion.—This is a rare species in the Benbolt formation, where it occurs
with the large O. multicostellata. The O. parva is typified by its small size and
rotund form. In these respects it is like O. holstonensis, but its ribbing is too
strong to be confused with that species. It is narrower, more rotund, and more
strongly costellated than O. planiventra and O. recta.

OXOPLECIA PENNSYLVANICA Cooper, new species
Plate 104, C, figures 12-19

Shell of about medium size for the genus, wider than long, broadly subellipti-
cal in outline with rounded sides and short hinge. Strongly uniplicate. Flanks
marked by 7 to 9 broad, subangular to rounded costae with intercalations near
the anterior margin ; fold marked by 4 strong costae; sulcus marked by 3 major
costae.

Pedicle valve moderately convex in lateral profile and with the maximum
curvature just posterior to the middle; anterior profile fairly strongly convex.
Umbonal region swollen; sulcus originating 2 to 3 mm. anterior to the beak,
narrow and deepening anteriorly ; tongue moderately long and narrowly rounded ;
flanks bounding sulcus flattened to gently convex and with steep lateral slopes.

Brachial valve fairly evenly and fairly strongly convex in lateral profile and
with the umbonal region the most inflated part; anterior profile fairly strongly
convex; fold originating on the anterior side of the umbo, narrow and fairly
strongly elevated anteriorly where its sides are steep. Flanks moderately swollen
and with steep lateral slopes.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PaOlOb ype ed PARE, VOL 10.4 10.0 12.9 7.4 8.1
PoC G DE ck. vf Peictads. alae or.a 4 WON 13.9 12.7 15.5 sfh iP 9.0

Types.—Holotype: 117119a; unfigured paratype: 117119b.

Horizon and locality Dark shale originally referred to Rodman member of
the Nealmont formation but now called Salona formation (base) in Pennsy]l-
vania: At Bellefonte, Bellefonte (15’) Quadrangle; 4 mile north-northwest of
Oak Hall, Bellefonte (15’) Quadrangle; old quarry 1 mile north-northeast of
Bellefonte, Bellefonte (15’) Quadrangle; 4 mile north of Roaring Springs, Hol-
lidaysburg (15’) Quadrangle.

Discussion.—This species is one of the strongly costellated forms. It suggests
O. magnaplicata more than any other species, but it is less umbonate and less
convex in the brachial valve and has a more erect beak on the pedicle valve and
a longer interarea.

554 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

OXOPLECIA PLANIVENTRA Cooper, new species
Plate 102, C, figures 25-32

Shell of about medium size for the genus, transversely elliptical in outline with
narrowly rounded sides and gently rounded anterior margin. Hinge moderately
wide. Pedicle tongue short, broadly rounded. Broadly uniplicate. Greatest width
at or near the middle. Fold marked by 5 or 6 costellae, sulcus by 5 or 6 and the
flanks by about 12 costellae, those of the posterolateral areas low and indistinct.
Fila strong, about 5 to the millimeter in the middle.

Pedicle valve slightly to gently convex in lateral profile; anterior profile
broadly and barely convex; umbo gently inflated; sulcus originating about 2 mm.
anterior to the beak, broad and shallow throughout. Flanks bounding sulcus flat
to gently convex and with gentle slopes to the margins. Interarea moderately
long, curved, apsacline. Beak moderately long.

Brachial valve fairly evenly and strongly convex in lateral profile and with
the maximum convexity located near the middle. Anterior profile strongly
arched; umbonal region swollen ; fold not strongly elevated in the median region
but only gently elevated in the anterior region. Flanks bounding fold only gently
inflated but with steep slopes to the margins.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype: lig... iSiGr 2. 2h 10.6 9.6 14.2 8.3 6.6
Paratype (117I2Ia) ..... nhie's'et) EO 9.2 13.1 7.7 6.8

Types.—Holotype: 117120; figured paratype: 117121a; unfigured paratype;
11712Ib.

Horizon and locality —Sevier formation in Louisville (T.V.A. 138-SE) Quad-
rangle, Tennessee: 4 mile northeast of Miser; 4 mile north of Gooseneck.

Discussion.—This is one of the numerous small species of Oxoplecia occurring
in the interval between the Lenoir and Benbolt. It is specially characterized by
the flatness of the pedicle valve in both profiles. This feature distinguishes it
from all the other small species except O. recta. That species has a more erect
beak on the pedicle valve, a not quite so flat pedicle valve, a more umbonate
brachial valve, and a generally rounder outline.

OXOPLECIA PLANULATA Cooper, new species
Plate 104, D, figures 20-24

Shell large for the genus, subquadrate in outline; sides broadly and gently
rounded ; anterior margin lobate; hinge narrow. Costellae broad and irregular,
II to 13 on the flanks, 6 on the fold, and 5 in the sulcus. Fila closely crowded,
about 8 to the millimeter at the middle of the brachial valve.

Pedicle valve gently convex in lateral profile and with a moderate swelling in
the umbonal region. Anterior profile broadly and gently convex; sulcus origi-
nating 5 mm. anterior to the beak, narrow in the median region but flaring some-
what toward the front. Sulcus occupying less than half the width at the front

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 555

margin. Tongue short and broadly rounded. Plicae bounding sulcus moderately
strong ; flanks nearly flat and with gentle slopes. Interarea long, gently apsacline.

Brachial valve gently and evenly convex in lateral profile but with a swollen
umbonal region ; anterior profile broadly and gently convex. Fold originating just
anterior to the umbo, low and narrow, expanding anteriorly; fold only mod-
erately elevated above the flanks, most strongly elevated at the front. Flanks
gently inflated and with moderate slopes to the margins.

Measurements in mm.—Holotype, length 21.4, brachial length 19.0, width
24.0, hinge width 14.3, thickness 10.0.

Type.—Holotype: 117122.

Horizon and locality.—Carters formation (O.roplecia bed) in Alabama: In the
quarry 0.3 mile north of Gate City, Leeds (15’) Quadrangle.

Discussion.—This is a large species with strong costellae but it differs mark-
edly from all the other large forms described herein in the strongly erect beak
of the pedicle valve, the long interarea, and the shallowness of both valves. The
species has an exceptionally compressed profile for such a large form.

OXOPLECIA PLICATA Cooper, new species
Plate 104, E, figures 25-31

Shell small for the genus, transversely elliptical in outline with narrowly
rounded lateral margins and broadly truncated anterior margin. Hinge wide,
equal to more than half the shell width. Surface costellate, the sulcus occupied
by 4 costellae and the fold by 6. Flanks marked by about 18 costellae.

Pedicle valve gently convex in lateral profile with the greatest curvature in
the umbonal region. Beak prominent, elongated ; posterior median half of valve
gently convex ; sulcus originating at about the middle, deepening rapidly and oc-
cupying about half the width at the front margin. Slopes into sulcus deep and
abrupt ; flanks bounding sulcus gently convex with gentle slopes to the margins ;
slopes to cardinal extremities steeper than those to margins but gentle neverthe-
less. Ridge on pseudodeltidium prominent ; interarea curved, apsacline.

Brachial valve strongly convex in lateral profile, about three times as deep as
the pedicle valve. Fold originating about one-third the length from the beak;
umbonal region slightly swollen ; beak low and inconspicuous. Fold strongly ele-
vated in the anterior portion with steep and abrupt slopes to the flanks, which
are strongly convex and have steep slopes to the margins.

Measurements in mm.—Holotype, length 9.1, brachial length 8.7, width 11.8,
hinge width 7.0, thickness 7.1.

Type.—Holotype: 117123.

Horizon and locality—Red Knobs formation in Tennessee: # mile east of
Friendsville, Louisville (T.V.A. 138-SE) Quadrangle.

Discussion.—This species is characterized by its small size, narrowly and trans-
versely elliptical outline, and fine costellae. It has some of the features of small
specimens of O. holstonensis but is wider and more distinctly marked.

550 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

OXOPLECIA RECTA Cooper, new species
Plate 104, A, figures 1-6

Shell small for the genus, slightly wider than long; often somewhat distorted ;
sides somewhat narrowly rounded ; anterior margin truncated ; widely uniplicate ;
hinge moderately wide. Surface strongly costellate; costellae numbering about
13; fold and sulcus with 5 to 8 costellae. Fila strong, numbering 5 to the milli-
meter in the middle of the pedicle valve.

Pedicle valve gently convex in lateral profile with the region between the mid-
dle and the beak somewhat swollen; anterior profile gently and broadly convex ;
beak long and pointed ; umbo somewhat flattened ; sulcus originating about 3 mm.
anterior to the beak; sulcus broad and moderately deep, occupying more than
half the width at the front margin. Tongue long and broadly rounded. Flanks
bounding sulcus flattened and with little slope to the margins. Interarea long,
curved, apsacline.

Brachial valve moderately convex in lateral profile; strongly arched in an-
terior profile: Fold wide but low and rounded; flanks bounding fold gently
inflated but with moderate lateral slopes.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype 2020. A. Pee II.9 10.3 13.4 8.8 Fi
Paratype) (207124) 21a. ik 12.6 10.6 13.9 9.2 7.8

Types.—Holotype: 110849a; figured paratype: 117124; unfigured paratypes:
110849b,c.

Horizon and locality—Lincolnshire formation (Hogskin member), in Ten-
nessee: On Sally Cleveland Farm, 3 mile southwest of Washburn, Dutch Val-
ley (T.V.A. 154-SE) Quadrangle; 0.4 mile northeast of Red Hill, 44 miles west-
southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle; school at
Chesney, 2 miles northeast of Luttrell, Luttrell (T. V. A. 155-NW) Quadrangle.

Lincolnshire formation in Tennessee: 4 mile north of Eidson, Kyles Ford
(T.V.A. 170-SE) Quadrangle.

Discussion.—This species is most similar to O. planiventra. The differences
between them are discussed under that species.

OXOPLECIA SIMULATRIX (Bassler)
Plate 1o1, A, figures 1-10; plate 1o1, B, figures 11-15

Triplecia (Cliftonia) simulatrix BAssLer, Cambrian and Ordovician: Maryland Geol. Surv.,
p. 266, pl. 40, figs. 11-13, 1919.

Shell of large size, transversely elliptical in outline with the length equal to
about three-fourths the width. Lateral margins narrowly rounded, anterior mar-
gin truncated. Width of hinge slightly more than half the shell width. Surface
strongly multicostellate, with the sulcus occupied by 6 to g costellae and the fold
by 7 to 10. Flanks marked by 15 to 18 low, rounded costellae separated by

PART,,.£ CHAZYAN AND RELATED BRACHIOPODS—COOPER 557

interspaces of about the same width as the costellae. Concentric fila numerous,
about 5 in 1 millimeter near the middle.

Pedicle valve moderately convex in lateral profile and with the greatest con-
vexity in the umbonal region; sulcus originating 3 to 4 mm. anterior to the
beak, widening gradually to the front margin where it occupies about one-half
the width. Flanks bounding sulcus flattened, slopes to lateral margins moder-
ately steep. Tongue moderately long, broadly rounded. Beak low, strongly in-
curved; interarea moderately long ; apsacline.

Brachial valve moderately convex in lateral profile but with a narrowly rounded
umbo; anterior profile broadly and moderately convex; beak small, protruding
slightly beyond the posterior margin. Fold originating on the strongly curved
umbo, heightening anteriorly but only moderately elevated at the front margin.
Flanks moderately convex but with steep slopes to the margins.

Interior: Pedicle valve with nearly obsolete dental plates, and delthyrial cavity
nearly filled with callus; foramen functional, minute; diductor scars flabellate.
Brachial valve with long, curved cardinal process.

Measurements in mm.—
Brachial Hinge
width

Length length Width Thickness
MMECLOEV PO sie b tiia.vs oo asia Ss5'e 8.8+ 8.7+ 12.8 ? 6.4
Hypotype *( 817127). 00. ss 12.2 II.0 T5a0 10.0 9.5
i (GO7500a) li. FPR 17.0 16.3 22.5 15.5 14.1

Types.—Lectotype: 66175 ; figured hypotypes: 97599a, 117127; figured para-
type: 117128.

Horizon and locality—Lectotype from Chambersburg (Sinuites bed)
(=Oranda in part) in Pennsylvania: 1 mile south of St. Thomas, Mercersburg
(15’) Quadrangle; 1 mile north of Guilford Springs, 24 miles southwest of
Chambersburg ; 34 miles north of Greencastle, Chambersburg (15’) Quadrangle ;
Carlisle, Carlisle (15’) Quadrangle.

Oranda formation in Virginia: Along the railroad 4 mile west of Strasburg ;
U. S. Highway 11, 2 miles southeast of Strasburg; on Virginia Highway 55,
0.4 mile west of U. S. Highway 11, north edge of Strasburg, Strasburg (15’)
Quadrangle; north of the road 0.6 mile northwest of Linville Station, Broadway
(15’) Quadrangle; Strickler Farm, junction of Virginia County Highways 961
and 962, west of Edinburg; below the dam on the north branch of the Shenan-
doah River, 14 miles north of Edinburg; on Bowman Farm, east of U. S. High-
way II, about 1 mile south of Woodstock, Edinburg (15’) Quadrangle; 13
miles east-northeast of Long Glade; just west of the junction of Virginia County
Highways 617=910, and 777, 900 feet north-northwest of Green Mount Church,
Broadway (15’) Quadrangle; Cedar Grove Church, 200 yards on Virginia
County Highway 616 east of U. S. Highway 11, 35 miles southwest of Mount
Jackson, Mount Jackson (15’) Quadrangle.

Discussion.—The type lot of this species consists of four cotypes. Examina-
tion of the specimens makes it clear that they come from different strata and
that they are not the same species. One of the cotypes (pl. 49, fig. 11.) is said

558 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

to have come from the Sinuites bed at the base of the Martinsburg shale, 1 mile
south of St. Thomas, Pa. Although this specimen is a badly exfoliated interior
filling and an immature specimen, it is nevertheless selected as lectotype. No
other choice is possible because the remaining three specimens are all of dubious
value.

The specimens illustrated by figures 12 and 13 on plate 49 are very poorly
preserved and are evidently derived from a shaly matrix. The specimen shown
in figure 12 is a fragment of a brachial valve showing the umbonal part and the
brachiophores but not preserving the cardinal process. The figure is approxi-
mately natural size. The specimen illustrated by figure 13 is a complete speci-
men but is badly crushed. The illustration is approximately x2. These two
specimens bear the catalogue number 66174. The label accompanying them
reads: “Trenton (bed VII of section), Strasburg, Va.” This bed according to
Ulrich’s notes corresponds to the lower Edinburg (Cyrtonotella zone) of Cooper
and Cooper. Thus these specimens have nothing to do with the lectotype which
occurs hundreds of feet higher. These specimens are assigned somewhat doubt-
fully to O. multicostellata which is identified in the Cyrtonotella beds in the
vicinity of Strasburg.

The third cotype under number 66174 is another immature but complete speci-
men which is the best preserved one of both lots. It could not, however, be se-
lected as the lectotype because its horizon and locality are equivocal even though
it appears under the above number. This specimen is dark gray, lustrous, and
gives the appearance of having come from the higher beds of St. Thomas or even
of Strasburg. It resembles numerous specimens of the Oranda formation from
Virginia more than it does those from the shaly beds of the lower Edinburg
formation. This equivocal specimen is here referred to O. simulatrix, but its
stratigraphic horizon is uncertain.

With reference again to the lectotype, it must be stated that the specimen is
immature. The figure and its legend given by Bassler give no indication of the
enlargement of the figure. The figure is actually approximately x2. The speci-
men is quite unlike the figure, which is retouched to such an extent that it is
difficult to identify the specimen with it. The figure shows prominent costellae,
and the sulcus occupied by 2 long and 2 short costellae. These give an entirely
erroneous idea of the species because the lectotype is so exfoliated that only the
stronger parts of the ornamentation are exhibited.

Confidence is here expressed that the lectotype is the young of the common
O-xoplecia of the Oranda formation; therefore the name simulatrix is used for
it. The above description is based on adult material from many localities and
is thought to represent the species more accurately.

As defined herein O. simulatrix resembles some of the larger species found in
the Appalachians. It is suggestive of O. multicostellata but differs importantly in
its stronger ornamentation and profiles. Its differences from O. nevadensis are
also in exterior details of ornamentation, fold and sulcus, and outline and pro-
files. It differs from O. pennsylvanica, which is approximately contemporaneous,
in its less strong costellae and its more robust profiles.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 559

Suborder SYNTROPHIOIDEA Ulrich and Cooper, 1936
Superfamily SyNTROPHIACEA Schuchert and Cooper, 1931
Family SYNTROPHOPSIDAE Ulrich and Cooper, 1936

Smooth or ribbed Syntrophiacea having long, convergent, subparallel septa in
the brachial valve.

Genus RHYSOSTROPHIA Ulrich and Cooper, 1936

Rhysostrophia Utricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 630, 1936; Geol. Soc.
Amer. Special Pap. 13, p. 240, 1938.

This genus is known from the high “Pogonip” of Nevada where it is repre-
sented by two species. It is also known from certain boulders in the Mystic
conglomerate, which have produced two additional species. Its range is now
extended to Newfoundland where it occurs in the Table Head series.

RHYSOSTROPHIA ELLIPTICA Ulrich and Cooper
Rhysostrophia elliptica ULR1IcH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 240, pl 54C,
figs. 5, 6, 1938.

Types——Holotype: 91176c ; paratypes: 91176a,b,d-f ; 92883a,b.

Horizon and locality—Mystic conglomerate in Stanbridge Township, Quebec,
Canada: 2.6 miles north and 4 mile east of Mystic, Range 6, Lot 21, and Range 6,
Lot 20.

RHYSOSTROPHIA NEVADENSIS Ulrich and Cooper
Rhysostrophia nevadensis Utricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 630, 1936;
Geol. Soc. Amer. Special Pap. 13, p. 241, pl. 54D, figs. 9-11, 13-19; text fig. 10, 1938.

Types.—Holotype: 91172; paratypes: 92884a-e.

Horizon and locality—Upper Pogonip group (Rhysostrophia zone) in Ne-
vada: I mile above the mouth of Ikes Canyon, east side of Toquima Range,
Roberts Mountains (1°) Quadrangle.

RHYSOSTROPHIA OCCIDENTALIS Ulrich and Cooper
Plate 112, B, figures 3-7
Rhysostrophia occidentalis ULricH and Cooper, Journ. Paleont., vol. 10, No. 7, p .630, 1936;
Geol. Soc. Amer. Special Pap. 13, p. 242, pl. 54B, figs. 3, 4, 7, 8, 12, 1938.
Types.—Holotype: 91174; figured hypotype: 117163.
Horizon and locality Same as preceding.

RHYSOSTROPHIA TRANSVERSA Ulrich and Cooper

Plate 109, F, figures 30, 31

Rhysostrophia transversa ULRicH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 630, 1936;
Geol. Soc. Amer. Special Pap. 13, p. 242, pl. 54A, figs. 1, 2, 1938.

Types.—Lectotype: 91175b; paratypes: Q1175a,c.
Horizon and locality.—Mystic conglomerate in Quebec, Canada: Range 6,
Lot 20, Stanbridge Township.

560 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

RHYSOSTROPHIA sp. 1
Plate 32, D, figures 7, 8

This is a small pedicle valve with deep sulcus and having a shallow spondylium.
The ornamentation consists of narrowly rounded and closely crowded costellae.
The specimen indicates a smaller species of the genus than hitherto seen in
Nevada and one that is probably lower stratigraphically than the other known
species.

Figured specimen.—17228.

Horizon and locality—Pogonip group (Desmorthis zone) in Nevada: On
the west side of Goodwin Canyon, Eureka District.

RHYSOSTROPHIA sp. 2
Plate 112, A, figures I, 2

This is a small species with rectangular outline but not so strongly transverse
as R. transversa. The specimens measure 7 to 8 mm. wide and 5 and 6 mm. long.
The pedicle valve is deeply sulcate, and the brachial valve has a strong, elevated
fold.

Figured specimens.—117162a,b.

Horizon and locality—Table Head series (upper) in Newfoundland: At
Table Point.

Family BREVICAMERIDAE Cooper, new family ‘

Syntrophioidea having a sessile cruralium in the brachial valve.

BREVICAMERA Cooper, new genus

(Latin brevi, short; camera, chamber)

Shell small, approaching 4 inch in width; broadly and transversely elliptical ;
uniplicate ; surface paucicostate. Biconvex ; valves of subequal depth; hinge nar-
row ; interareas reduced.

Pedicle interior with small teeth ; spondylium short, dental plates short ; median
septum short.

Brachial interior with deep, narrow notothyrial cavity bounded by short sub-
parallel brachiophore plates; brachiophores short, crescentic in section, tied to
inner wall by short, inconspicuous fulcral plates. Brachiophores at place of ar-
ticulation provided with a small articulating process opposite the fulcral plate.
Brachiophore plates joining a callosity on the valve floor to form a sessile cru-
ralium ; floor callosity extended anteriorly between muscle scars as a low median
ridge ; muscle area small, divided into halves by the median ridge; posterior ad-
ductors small and narrow; anterior adductors large and subcircular, situated
posterolaterally of the anterior scars.

Genotype.—Brevicamera camerata Cooper, new species.

Discussion—The exterior features of this genus are suggestive of the syntro-
phids in the long tongue of the pedicle valve and the corresponding high and nar-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 561

row fold, rather than recalling any members of the Camerellidae. Among the
latter the transverse form is suggestive of Parastrophina, but usually the brachial
valve of that genus is proportionately much deeper and more swollen than the
pedicle valve. In these respects it is thus quite unlike Brevicamera.

Although the exterior of Brevicamera is not unusual, the interior characters
are, especially those of the brachial valve. The spondylium of the pedicle valve
presents no unusual features. It is small and narrow at the front, and the dental
plates are short. Actually the whole structure is fairly small when compared to
some other genera such as Camerella itself. The median septum is short and
does not extend anterior to the spondylium. In this respect the genus is unlike
most related genera. If one can judge by genera at the summit of the syntrophid
line and of the Gypidulinae, abbreviation of the septum is an advanced charac-
ter which appears late in a lineage.

The brachial valve is the one which gives definition and focus to the genus be-
catise no camerellid like it is known. The entire cardinalia are of interest. The
brachiophores are short but somewhat bulbous opposite the socket. At this point
they have a small process, directed obliquely toward the opposite valve, which
must serve as an accessory articulating nub. The socket is defined in part by a
small fulcral plate. The blade of the brachiophore is short and cresentic in sec-
tion. Brachiophore plates are subparallel and extend nearly vertically to the floor
of the valve where they join a callosity to form a sessile cruralium. The anterior
end of the callosity is extended anteriorly to divide the small and confined muscle
field into two parts. The sessile cruralium is quite unlike the brachial structure
of any known genus although loss of median septum occurs in the peculiar genus
Plectocamara.

Specimens of Brevicamera so far have been found only in the Pratt Ferry ex-
posures in Alabama, and here they are rare indeed.

BREVICAMERA CAMERATA Cooper, new species

Plate 118, A, figures 1-10; plate 119, FE, figures 15, 16

Small, transversely elliptical in outline; sides oblique, straight, forming an
apical angle of about 120°. Sides narrowly rounded; anterior margin nearly
straight. Valves convex, the brachial valve slightly deeper than the pedicle valve.
Anterior commissure narrowly and steeply uniplicate. Surface smooth except
for the anterior margin which is marked by a few costae, 2 on the flanks, 3 or
4 on the fold, and 2 in the sulcus, the latter confined to the tongue.

Pedicle valve gently convex in lateral profile but with the maximum curvature
in the posterior half; anterior profile broadly and gently convex. Umbonal re-
gion narrowly swollen; median region inflated. Sulcus originating abruptly at
the middle, fairly wide, deepening rapidly. Tongue geniculated at a right angle,
long, narrow, and truncated at the front. Flanks bounding sulcus marked by a
strong plica that extends indistinctly for some distance in a posteromedian di-
rection. Flanks inflated and with steep slopes. Interior with short, narrow, and
delicate spondylium. Interarea nearly obsolete.

562 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve gently convex in lateral profile but with a strongly inflated
umbo; anterior profile broadly but strongly convex. Median region inflated, fold
originating at the middle, narrow, strongly elevated. Flanks swollen, narrowly
rounded, and depressed. Interior with sessile cruralium, short median ridge, and
small adductor field.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (brachial valve)........ ? 73 0.2 1.9 2.2?
Paratype (pedicle valve 117154a). 6.1 ? 0.4 2.0 2.0?

Types——Holotype: 117154c; figured paratypes: 117154a,b.

Horizon and locality About 3 feet above the base of the Pratt Ferry forma-
tion in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—No other species of this genus is known to which B. camerata
may be compared.

Family CAMERELLIDAE Hall and Clarke, 1804

Biconvex, narrow-hinged Syntrophiacea having a small cruralium duplex in the
brachial valve ; interareas reduced or obsolete.

Subfamily CAMERELLINAE Hall and Clarke, 1894

Camerellidae having a spondylium simplex in the pedicle valve.

Genus CAMERELLA Billings, 1859

Camerella Brttincs, Canadian Nat., vol. 4, p. 301, 1859.
Rhynchocamara SCHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 180,
1932.

CAMERELLA ANTEROPLICATA Cooper, new species
Plate 111, F, figures 46-54; plate 111, G, figures 55-63

Shell of about medium size for the genus, slightly wider than long and with
the greatest width at about the middle; outline forming a depressed oval; pos-
terolateral margins straight, directed obliquely and forming an angle slightly
more than go°. Sides narrowly rounded; anterior margin broadly rounded;
anterior commissure strongly uniplicate. Posterior half of shell smooth, anterior
half costate with 2 to 3 costae on the flanks, 3 to 4 on the fold, and 2 to 3 in the
sulcus.

Pedicle valve less deep than the brachial valve; gently convex in lateral pro-
file with the maximum convexity slightly posterior to the middle; anterior pro-
file broadly and gently convex ; umbonal and median regions moderately inflated ;
sulcus short and shallow, originating just anterior to the middle; tongue short,
serrate; flank bounding sulcus moderately swollen. Costa bounding sulcus
stronger and more elevated than the others. Beak short, incurved, protruding
slightly posterior to the brachial umbo.

Brachial valve fairly strongly and evenly convex in lateral profile and with

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 563

maximum convexity at about the middle; anterior profile strongly domed but
crest of dome somewhat flattened ; umbonal and median region strongly inflated ;
fold short and low.

Measurements in mm.—
Brachial Hinge
Length length Width width Thickness
Slee.” ieee aS 8 ae arn 8.2 8.0 8.5 1.5 5.6
Picured specimen ©. 5/..0s.%.... 7.0 6.9 7.0 1.6 4.7+

Types.—Holotype: 117129; figured specimen: 111341.

Horizon and locality.—Bromide formation (Pooleville member-Oxoplecia
gouldi zone) in Oklahoma: At Rock Crossing, about center sec. 35, T. 5 S.,
R. 1 E., Criner Hills, Carter County.

Discussion.—This species is characterized by its smooth posterior three-quar-
ters or more and the strong anterior costation. The brachial valve is swollen, and
the umbo is elevated almost flush with the beak of the pedicle valve. This species
is very similar to Camerella sp. 3 from the Benbolt limestone in general appear-
ance, but the latter is a somewhat wider shell with a less convex brachial valve
and less produced umbo. The apical angle of the Oklahoma species is less than
that of the Benbolt form, and the sulcus of the latter is deeper and originates
nearer the middle.

CAMERELLA BELLA Fenton
Plate 112, C, figures 8-15

Camerella bella Fenton, Amer. Midland Nat., vol. 11, p. 136, pl. 3, figs. 1-12, 1928.

Shell of medium size for the genus, subpentagonal to suboval in outline, slightly
longer than wide. Greatest width in the anterior third. Beak angle about 87°,
defined by nearly straight posterolateral margins; lateral margins narrowly
rounded. Anterior margin truncated. Surface costate; 2 or 3 costae occupy the
sulcus, while 3 or 4 occur on the brachial fold. Flanks marked by 4 costae.

Lateral profile of pedicle valve with maximum curvature in the posterior third,
the anterior two-thirds somewhat flattened. Anterior profile a depressed arch.
Sulcus originating abruptly at 74 mm. anterior to the beak, shallow and widen-
ing slightly anteriorly to occupy a little more than half the width at the front
margin. Tongue moderately long, truncated. Umbo somewhat swollen pos-
teriorly but flattening anteriorly to the place of origin of the sulcus. Flanks mod-
erately elevated above the sulcus anteriorly, slightly convex and with gentle slopes
to the margins.

Brachial valve fairly strongly convex in lateral profile with the greatest curva-
ture at the umbo; somewhat narrowly rounded in anterior profile. Umbonal and
central region somewhat inflated. Fold originating about 6 mm. anterior to the
beak, low and only slightly elevated above the flanks. Fold gently convex in
profile. Flanks gently rounded but with very steep slopes to the margins. An-
terior reentrant to receive tongue short.

Interior with a deep and fairly wide spondylium supported by a short septum

564 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

reaching to about the middle. Cruralium small and narrow, supported by a short
septum.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (pedicle valve 11110Im).... 12.7 ? 12.8 4.0 4.6
. (brachial valve 111101k)... ? [22 13.6 3.3 6.1
= Cay “e trEtepel) .. sae 13.8 13.2 2.9 0.7

Types.—Figured hypotypes: 111101k,m, I11102a; measured hypotype:
II1101-l.

Horizon and locality.—Plattin group (Macy formation) in Missouri: At the
Heck Place, 14 miles south-southeast of River aux Vasses, Weingarten (15’)
Quadrangle; Pacific, Pacific (74’) Quadrangle; northwest of Ste. Genevieve on
the road to Bloomsdale, Renault (15’) Quadrangle; 3 miles east of Auburn,
Elsberry (15’) Quadrangle; on the old road 1 mile northwest of the Chicago
Summer School Camp, NW4SW3 sec. 32, T. 37 N., R. 9 E., Weingarten (15’)
Quadrangle.

Carters limestone in Tennessee: Below the bentonite just east of Round Lick
Creek on U. S. Highway 7oN at Rome, Smith County; below the bentonite
0.8 mile east of Readyville on the north side of U. S. Highway 70S, Rutherford
County.

Discussion.—This species is characterized by its fairly large size, strong fold-
ing, and the half costate exterior. The costation is like that of Camerella plicata
(Schuchert and Cooper) in having 2 costae in the sulcus and 3 on the fold, but
the costation extends to the middle whereas it is confined to the anterior third
in C. plicata. Furthermore, the pedicle umbo of C. bella is more inflated and
the fold of the brachial valve originates just posterior to the middle in C. bella.

CAMERELLA BICOSTATA Cooper, new species
Plate 106, H, figures 45-54; plate 111, A, figures 1-15

Shell moderately large for the genus, wider than long with the greatest width
slightly anterior to the middle. Beak forming an angle slightly greater than a
right angle. Posterolateral margins widely divergent; anterolateral extremities
narrowly rounded; front margin nearly straight. Surface with posterior half
smooth, anterior half marked by 11 costae, 2 occupying the sulcus, 3 on the fold,
and 3 or 4 on the flanks.

Pedicle valve slightly less deep than the brachial valve, gently convex in lat-
eral profile with the most convex part just anterior to the umbo. Sulcus originat-
ing at about the middle, deepening abruptly but widening gradually anteriorly,
where it occupies about half the valve width. Flanks flat to gently concave in
profile and with gentle slopes.

Brachial valve gently convex in lateral profile and with the most convex part
in the umbonal region; nearly semicircular in anterior profile. Fold not greatly
elevated above flanks which are gently convex and slope steeply to the margins.
Umbonal region moderately convex.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 565

Measurements in mm.—
Brachial

Length length Width Thickness
Rinietysetes. santkias. oc) ea... 11.2 10.3 13.7 7.4
Patsevne (TiF11Gd)). «= ..+ 04 Ti, 11.6 13.9 7.9
= (Oe) See 10.6 10.2 12.4 6.8

Types.—Holotype: 117130b; figured paratypes: 111106, I11110a, 117130a;
unfigured paratypes: I11110b-d.

Horizon and locality——Lincolnshire formation (Hogskin member) in Tennes-
see: In the Sowerbyites zone, on road to Thorn Hill, 0.4 mile east of Red Hill,
SW4NW subquad. of Avondale (T.V.A. 162-SW) Quadrangle; 2.1 miles south-
west of Mount Eager Church, Hogskin Valley, Powder Springs (T.V.A.
154-SW) Quadrangle; 1 mile southeast of Washburn, Dutch Valley (T.V.A.
154-SE) Quadrangle; 3 miles west-southwest of Thorn Hill, Avondale (T.V.A.
162-SW) Quadrangle; 2 miles southwest of Hall Crossroad, NW4 center sub-
quad. of Fountain City (T.V.A. 146-SW) Quadrangle.

Discussion.—This species is characterized by its fairly large size, 2 costae in
the sulcus, and the lack of ornamentation on the posterior part. It differs from
the bicostate C. edmundsoni in its larger size, less completely costate valves, and
wider form. It differs from C. plicata, which it resembles in costation, by its
different proportions, C. bicostata being wider than long.

CAMERELLA BREVIPLICATA Billings
Plate 115, E, figures 32-34

Camerella breviplicata B1tt1ncs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 304, fig. 295,
1865.

Rhynchocamera breviplicata Billings, ULrtcH and Cooper, Geol. Soc. Amer. Special Pap. 13,
Pp. 251, 1938.

Type.—Holotype: G.S.C. 759.

Horizon and locality Boulder in Mystic Conglomerate in Quebec: In Range
6, Lot 20, Stanbridge Township.

Discussion.—This is one species of a group common in the upper part of the
Canadian which has a strongly inflated brachial valve but a smaller pedicle valve
and is costate only at the anterior.

CAMERELLA COSTELLATA Cooper, new species
Plate 112, G, figures 34-41; plate 118, C, figures 20-29

Shell fairly large for the genus, transversely and broadly elliptical in outline ;
posterolateral margins straight, forming an angle of about 110°; greatest width
slightly anterior to the middle; lateral margins narrowly rounded ; anterior mar-
gin gently rounded. Anterior commissure somewhat narrowly uniplicate. Beaks
and umbos smooth, anterior two-thirds costellate, with about 20 to 27 costae at
the anterior margin, 5 to 7 in the sulcus.

Pedicle valve evenly and strongly convex in lateral profile with the greatest
convexity at about the middle; anterior profile broadly convex, with moderately

566 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

sloping sides. Sulcus shallow, originating about 9 mm. anterior to the beak and
occupying about half the width. Floor of sulcus convex and with a short tongue.
Flanks bounding sulcus moderately convex. Median septum supporting a nar-
row spondylium and extending to the center.

Brachial valve nearly as deep as the pedicle valve, moderately convex in lateral
profile but with an inflated umbo; anterior profile strongly arched and with pre-
cipitous sides. Fold low and inconspicuous, originating at or near the middle;
flanks swollen. Umbonal and median regions inflated. Cruralium short, mod-
erately deep ; septum short.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PAECIE VETS: pate ohn’ ne ruaigshattie weet pin idle s\n ins 12:7 12.3 14.9 4.0 10.2
Paratype (pedicle valve IIIII3a)..... 12.8 ? 13.6 ? 3.0
ef (brachial valve 111113b).... ? 11.3 14.4 ? 2.6

Types.—Holotype: 117131; figured paratypes: I111113a,b.

Horizon and locality—Elway formation in Tennessee: $ mile southwest of
Mount Eager Church, Powder Springs (T.V.A. 154-SW) Quadrangle; U. S.
Highway 25E, north of Evans Ferry, Howard Quarter (T.V.A. 162-NW)
Quadrangle.

Elway formation in Virginia: At Eggleston, Giles County.

Discussion.—This species is characterized by its broadly elliptical outline and
the nearly completely costate shell. The species is suggestive of C. elliptica, but
that species attains a considerably greater size and differs in having much more
strongly defined costae, a more erect beak on the pedicle valve, and the sulcus
originating posterior to the middle. Camerella multiplicata is another Elway
species, but it is more triangular in outline and the ornamentation is more strongly
etched into the shell.

CAMERELLA EDMUNDSONI Cooper, new species
Plate 115, F, figures 35-42; plate 115,1, figures 50-52

Shell small, pentagonal in outline, with the length slightly greater than the
width. Greatest width at about the middle. Beak varying from a right angle to
an acute angle. Lateral margins straight and divergent to the anterolateral ex-
tremities which are moderately rounded. Surface marked by closely crowded,
rounded costae, 2 or 3 (occasionally 4) in the sulcus and 4 forming the fold.
Flanks marked by 3 costae.

Pedicle valve evenly convex in lateral profile with the maximum convexity at
about the middle; sulcus originating about one-third the length anterior to the
beak, shallow, and occupying about half of the width. Tongue short, generally
truncated. Umbonal region smooth, gently convex.

Brachial valve generally more circular in outline than the pedicle one and with
length and width about equal, slightly deeper than the pedicle valve. Moderately
convex in lateral and anterior profiles. Fold originating about one-third the

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 507

length from the beak, only slightly elevated above the flanks with are rounded
and have steep slopes. Umbonal region moderately curved.

Interior: Spondylium of pedicle valve in length equal to about one-third the
valve length; septum short and thin. Cruralium and septum of brachial valve
short.

Measurements in mm.—
Brachial

Length length Width Thickness
Holotype (pedicle valve) ............. 10.6 ? 9.9 3.0
Patdtype -(idtthze) van is. oteinan. ox 9.2 ? 8.4 3.9
ia (GAG Fer eRe, eee ey Tv 10.6 ? 10.1 2.6
ne (brachial valve 111117a)..... ? 30.8 10.2 4.6
# RUSEEIZO eee. we ke eet ce aoe ? 10.2 10.9 4.2
s Cristea Went: ae Pee. ? 10.4 10.3 4.4

Types.—Holotype: 111117b; figured paratypes: II111I7a,c-e, 117132a,b.

Horizon and locality—Poteet formation (Yellow Branch member) in Vir-
ginia: On the road along Yellow (Creek) Branch, 5 miles southeast of Rose
Hill, Rose Hill (T.V.A. 161-NE) Quadrangle.

Discussion.—This species is recognized by its elongate form and the nearly
complete costation of the surface. It most nearly resembles some of the variants
of C. plicata in which the valves are almost completely costate and the sulcus is
occupied by 3 costae, but differs from them in having a more elongate fold and
sulcus. The costation is similar to that of C. globularis, but that species is more
rotund in profile and is wider than long.

CAMERELLA ELLIPTICA Cooper, new species
Plate 113, E, figures 32-43; plate 113, F, figures 44-48

Shell large for the genus, wider than long with a broadly elliptical outline ;
beak forming approximately a right angle, sides narrowly rounded and front
margin nearly straight. Surface marked by 18 subangular costae of which 5
occupy the fold and 4 occur in the sulcus. Flanks with 6 costae.

Pedicle valve moderately convex in lateral profile with the greatest convexity
slightly posterior to the middle; beak short, slightly curved; umbonal region
gently convex. Fold originating about one-fifth the length anterior to the beak,
shallow and occupying slightly less than half the width at the front. Tongue
short, slightly rounded. Flanks gently convex and sloping moderately to the
margins.

Brachial valve slightly more convex than the pedicle valve in lateral profile
and with the greatest convexity at about the middle. Anterior profile broadly
but only moderately convex. Umbonal region strongly convex; fold low, only
slightly elevated above the flanks which are moderately convex and slope steeply
to the margins.

Interior: Spondylium in the pedicle valve long and slender, extending to a
point slightly posterior to the middle. Cruralium of brachial valve short but with
long brachial processes.

568 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—Holotype, length 14.5, brachial length 13.4, width 16.4,
thickness 10.3.

Types——Holotype: 111119d; figured paratypes: 98220a, I11119b,c; unfigured
paratypes: 98220b, I11119a; figured specimen: 117133a.

Horizon and locality—tLincolnshire formation in Virginia: At Marcem
Quarry, 2 miles west of Gate City, Gate City (T.V.A. 188-NE) Quadrangle.

Lincolnshire formation in Tennessee: On the north side of the road, 2 miles
southwest of Hall Crossroad, Fountain City (T.V.A. 146-SW) Quadrangle.

Discussion.—Large size, completely costate surface, and great width are the
features that serve to distinguish this shell from all others known. In its large
number of costae it is suggestive of C. multicostata but is larger and of different
proportions. Other described forms of such large size, such as C. gregeri and
C. volborthi, are generally only partially costate.

This species is more strongly costate and more deeply sulcate than C. costel-
lata from the Elway formation, which it resembles in outline and profile. It is
distinguished from C. globularis, which it resembles in profile, by its more finely
ornamented exterior and greater width.

Inside the brachial valve of one specimen the brachiophores are preserved in
their entirety, proving to be long and slender processes extending in the direc-
tion of the brachial valve.

CAMERELLA GLOBULARIS Cooper, new species
Plate 116, B, figures 6-20; plate 116, C, figures 21-24
Camarella sp. Butts, Virginia Geol. Surv. Bull. 52, p. 45, pl. 74, figs. 1-7, 1942.

Shell of about medium size for the genus, transversely subelliptical in outline,
and globular in profile. Sides strongly rounded, beak approximately a right
angle. Surface of posterior third smooth, anterior two-thirds marked by 14 to
16 broadly rounded costae separated by spaces less wide than the costae. From
I to 4 costae occupy the sulcus, and 4 to 5 mark the fold; flanks marked by 4
to 5 costae. Spondylium wide and deep.

Pedicle valve evenly and moderately convex with the maximum convexity
at about the middle; sulcus originating at about the middle of the valve, shallow,
and occupying somewhat more than half the valve width. Tongue short and
truncated. Flanks moderately rounded in profile and with steep slopes.

Brachial valve considerably deeper than the pedicle one, strongly convex in
lateral and anterior profile and with greatest convexity at the middle. Umbonal
and posterior region swollen; fold originating at about the middle, low and
rounded in profile. Flanks moderately rounded and with steep slopes. Brachial
interior with small cruralium.

Measurements in mm.—

Brachial
Length length Width Thickness
EIRP ce ies ce eee an cn Coote 13.3 12.6 14.8 11.8

Paratype (GotG@a) ss... .0t ere ee wee 12.2 10.8 12.4 0.6

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 569

Types.—Holotype: 117134; figured paratypes: 98192a,b; figured specimen:
117135.

Horizon and locahty.—Whistle Creek formation on Lexington (15’) Quad-
rangle, Virginia: On U. S. Highway 60, 100 yards southeast of Whistle Creek ;
2 miles northwest of Lexington.

Discussion.—Characterized by globular profile and presence of 3 to 4 costae
in the sulcus. Compared with C. plicata, which occasionally develops tricostate
forms, this species proves to be wider and more globular. It also differs from
C. quadriplicata Willard in possessing a more rounded profile and in having less
numerous costae on the flanks. Camerella globularis also resembles C. elliptica
but differs in its more convex profiles and the seminude exterior. Camerella
globularis shows considerable variation in the number of costae present in the
sulcus and on the fold. One specimen has a single costa in the sulcus, and others
have from 2 to 4. The two higher figures seem to represent the normal condition.

CAMERELLA GREGERI Cooper, new species
Plate 113, D, figures 20-31

Shell large for the genus, slightly wider than long and having a pentagonal
outline. Beak slightly greater than a right angle, anterolateral extremities nar-
rowly rounded, anterior margin truncated. Greatest width anterior to the mid-
dle. Surface smooth in the posterior half, but marked by subangular and com-
pressed costae with interspaces about as wide as the costae, 5 to 7 costae on the
fold, 4 to 6 in the sulcus, and 5 to 6 on the flanks.

Pedicle valve slightly convex in lateral profile with the greatest convexity just
anterior to the umbonal region. Sulcus originating at the middle, deepening
abruptly and occupying one-half to two-thirds the width at the front. Tongue
moderately long with a truncated extremity. Flanks gently convex and with
gentle slopes to the margins. Spondylium wide and deep, septum reaching
anterior to the middle.

Brachial valve about twice as deep as the pedicle valve, only moderately con-
vex in lateral profile but strongly arched in anterior profile. Fold originating at
the middle, truncated at the front and moderately elevated. Flanks rounded and
with steep slopes. Umbonal region strongly convex. Cruralium small.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EROGVE cc ce cat ics. ons 3 17.8 17.6 19.1 4.7 14.5
Parauype '( E8195) ew 2 17.2 16.8 17.8 3.8 12.8

Types.—Holotype: 111126; figured paratypes: 111125, 117136a,c; unfigured
paratype: 117136b.

Horizon and locality —Plattin group (Macy formation) in Missouri near
Glencoe, St. Louis County: Rockwoods Reservation, 20 miles west of Grover,
St. Louis County; on Fredericktown road 5 miles southwest of Ste. Genevieve,
Weingarten (15’) Quadrangle.

570 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion—This is the largest known species of Camerella, exceeding even
C. volborthi in size. It is also characterized by having numerous costae on the
fold and in the sulcus. These vary from 5 to 6 in the sulcus and 6 to 7 on the
fold. The species is thus unlike any other described form.

CAMERELLA IMMATURA Cooper, new species
Plate 110, A, figures 1-5

Shell small, subpentagonal in outline, slightly wider than long; apical angle
slightly greater than a right angle; sides narrowly rounded ; anterior somewhat
produced and truncated. Anterior commissure narrowly uniplicate; surface
smooth except for 2 costae on the flanks.

Pedicle valve gently convex in lateral profile and with the maximum convexity
at about the middle; anterior profile broadly and gently convex; median region
inflated; sulcus originating in the anterior third and anterior to the inflated
region; sulcus smooth, concave; tongue moderately long and narrow. Flanks
gently convex and with moderate slopes.

Brachial valve deeper than the pedicle valve and gently convex in lateral pro-
file with the umbo swollen. Anterior profile broadly and gently convex but with
precipitous sides. Median region and flanks inflated. Fold short, narrow, slightly
elevated, marked by a slight depression medianly.

Measurements in mm.—Holotype, length 5.5, brachial length 5.6, width 6.1,
hinge width 1.7?, thickness 4.0.

Type.—Holotype: 117137.

Horizon and locality—Chatham Hill formation in Virginia: On Grayson
Farm, 4 to 5 miles southeast of Bland, Bland County.

Discussion.—This species is characterized by its nude exterior and the lack of
costae in the sulcus and on the fold. No comparable species is available.

CAMERELLA INDEFINITA Cooper, new species

Plate 112, D, figures 16-22

Shell moderately large for the genus, slightly longer than wide with the great-
est width slightly anterior to the middle. Beak forming an acute angle of about
80°; sides narrowly rounded and anterior margin gently rounded. Surface
marked by 19 low, rounded costae separated by spaces narrower than the costae.
Six costae occupy the sulcus, and 7 occur on the fold.

Pedicle valve gently convex in lateral profile with the most convex part slightly
posterior to the middle. Sulcus poorly defined, originating at about the middle
and occupying about two-thirds the valve width at the anterior. Flanks narrow,
slightly convex but with steep slopes to the margins.

Brachial valve moderately convex with the greatest convexity slightly posterior
to the middle. Umbonal region moderately convex, fold poorly defined, wide,
originating slightly posterior to the middle. Flanks convex and with steep slopes.

Measurements in mm.—Holotype, length 13.7, brachial length 12.5, width 12.8,
hinge width 3.2, thickness 8.9.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 571

Type.—Holotype: 111127.

Horizon and locality——Elway formation, (35 to 55 feet above base of section)
in Tennessee: 4 mile northwest of Eidson, Kyles Ford (T.V.A. 170-SE) Quad-
rangle.

Discussion.—This species is distinguished from all others known by its elongate
form, narrow posterior, multiplicate shell, and the inconspicuous character of the
fold and sulcus, neither of which is strongly set off from the surrounding parts
of the shell. It is suggestive of C. leiorhynchoidea but is more strongly costate.

CAMERELLA ? LEIORHYNCHOIDEA Cooper, new species
Plate 114, D, figures 39-43

Shell of about medium size for the genus, all the specimens in a crushed state
and simulating common Letorhynchus (now Nudirostra) ; valves of nearly equal
depth and convexity. Surface completely costate except for beak region which is
smooth. Costae narrowly rounded, low, irregular. Greatest width anterior to
the middle. Interior of both valves with a long median septum.

Measurements in mm.—

Length Width
Eigictype, (nedicle WAlVE) oa. oles dons tne sly daca 13.4 13.0
Paratype (brachial Valve" 1x7138d) os «wees wc d+ te tay eks 10.8 10.4

Types.—Holotype 117138a; figured paratypes: 117138b-d; unfigured para-
types: 117138e-h.

Horizon and locality—Edinburg formation (Liberty Hall facies), just below
a siltstone with Paucicrura in Virginia: On the south side of U. S. Highway 33
in pasture road, between Peales Crossroads and Penn Laird, about 5 miles south-
east of Harrisonburg, Harrisonburg (15’) Quadrangle.

Discussion.—The material on which this species is based is not well enough
preserved to determine whether or not the genus is Camerella or Parastrophina.
It is referred doubtfully to Camerella because that is the commoner genus in the
Appalachians. The species can be recognized by its similarity to Letorhynchus
limitare.

CAMERELLA MINUTA Cooper, new species
Plate 113, C, figures 10-19

Shell small for the genus, subpentagonal in outline with the length and width
about equal. Beak angle slightly less than 90°. Posterolateral margins straight ;
lateral margins narrowly rounded with the greatest width located at about the
middle. Anterior margin gently rounded. Surface costate in the anterior half,
2 costae in the sulcus, 3 on the fold, and 3 or 4 on the flanks. Costae thick,
rounded.

Pedicle valve gently convex in lateral profile with the maximum convexity
about one-third the length from the beak; anterior portion somewhat flattened.
Posterior half somewhat swollen ; sulcus originating about 24 mm. anterior to the
beak at about the middle of the valve, widening anteriorly to occupy slightly more

572 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

than half the width at the front margin. Sulcus shallow, abruptly bent toward the
brachial valve to form a short, blunt tongue. Costae bounding sulcus strongly
subangular and prominent. Flanks slightly convex with moderately steep slopes.
Median septum reaching nearly to the middle of the valve.

Brachial valve moderately convex in lateral profile with the unbonal region
the most convex part. Anterior profile a narrowly rounded arch. Fold origi-
nating at about the middle, moderately elevated anteriorly with rounded de-
pressed flanks, steep lateral slopes.

Measurements in mm.—
Brachial

Length length Width Thickness
Piplotg pe... ose A. Ae cases 4.9 4.5 4.8 3.4
Paratype <+(LLIT20%) s5.00ld Lee cas 5.6 5.1 6.5 4.1
- CTGT IBS) opis SE tee 5.4 4.8 5.2 3.6

Types.—Holotype: 111131a; figured paratype: 111128e; unfigured paratypes:
I11128a-d, Il112Qa-c, I11130a,b, TII13Ib.

Horizon and locality —Effna formation in Virginia: At the McNutt Quarry,
12 miles southwest of Bland, Burkes Garden (15’) Quadrangle.

Botetourt formation in Virginia: Near Cedar Grove Church and School, 14
miles southeast of Harrisonburg, Harrisonburg (15’) Quadrangle; 1 mile north-
west of Lexington, Lexington (15’) Quadrangle; 2 miles south of Hogback
Mountain, 7 miles north-northeast of Lexington, Lexington (15’) Quadrangle;
Catawba Valley, at junction of Virginia Highways 114 and 311, 4 mile southwest
of Catawba Valley, Salem (15’) Quadrangle.

Chatham Hill formation in Bland County, Virginia: on Grayson Farm, 4
miles southwest of Bland; 6 miles southwest of Bland.

Discussion—This species is characterized by its small size and the usual
presence of 2 costae in the sulcus. The species is thus suggestive of members of
the genus Plectocamara, but it differs from all of them in its partially nude orna-
mentation and the presence of long septa. It is quite unlike any other described
species.

CAMERELLA MULTIPLICATA Cooper, new species
Plate 112, E, figures 23-29

Shell of about medium size for the genus, with length and width about equal ;
greatest width anterior to the middle, giving the shell a pentagonal outline. An-
terior margin truncated. Apical angle about 90°. Anterior commissure unipli-
cate. Surface marked by subangular costae of which 4 or 5 occupy the sulcus, 5
or 6 are on the fold, and 9 on the flanks.

Pedicle valve moderately and evenly convex in lateral profile with the great-
est convexity at about the middle. Sulcus originating about one-third the length
from the beak, shallow, and occupying about half the width at the front. Tongue
short, not strongly geniculated. Flanks gently convex with gentle slopes to the
margins,

Brachial valve somewhat more convex than the pedicle valve in lateral profile

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 573

and with the greatest convexity at about the middle. Anterior profile strongly
arched. Fold originating about one-third the length from the beak, low and
gradually widening anteriorly. Umbo slightly swollen with incurved beak. Flanks
narrowly convex and with steep lateral slopes.

Measurements in mm.—Holotype, length 11.6, brachial length 10.9, width 11.1,
thickness 8.0.

Type.—Holotype: 111153.

Horizon and locality—Elway formation in Tennessee: 4 mile northeast of
Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle.

Elway formation in Virginia: On Virginia Highway 71, 1 mile northeast of
Dickensonville, Hansonville (T.V.A. 205-SW) Quadrangle.

Whistle Creek formation in Virginia: On Virginia Highway 602, 54 miles
S. 82° W. of Middlebrook, Augusta County.

Discussion.—This species is characterized by the numerous direct costae mark-
ing the surface of the valves. It differs from C. indefinita in having its shell more
evenly and regularly costate and in possessing 5 costae in the sulcus instead of 6
as in C. indefinita. It differs from C. elliptica in the form of the valves, the latter
being a much wider shell.

CAMERELLA NUDA Cooper, new species
Plate 115, C, figures 12-21

Shell small for the genus, slightly longer than wide; oval in outline; apical
angle slightly greater than a right angle; greatest width at about the middle and
with narrowly rounded sides ; posterolateral margins sloping toward the middle;
anterior margin truncated. Posterior two-thirds smooth; anterior third marked
by distant and indistinct costae, 2 or 3 on the flanks and 3 in the sulcus.

Pedicle valve moderately convex in lateral profile; broadly and gently convex
in anterior profile; umbonal and median regions inflated; sulcus originating at
the middle; sulcus moderately wide and with its floor gently convex; sulcus
bounded by the two strongest costae on the valve; flanks swollen. Tongue mod-
erately long and rounded. Beak low.

Brachial valve with moderately convex lateral profile and strongly arched an-
terior profile with steep lateral slopes. Umbonal and median regions swollen.
Fold low and inconspicuous. Flanks swollen.

Measurements in mm.—Holotype, length 6.2, brachial length 5.6, width 6.0,
hinge width 1.0, thickness 4.4.

Types.—Holotype : 117139a; figured paratype: 117139b.

Horizon and locality—Murfreesboro formation in Tennessee: On Stone River
just west of U. S. Highway 70S, 14 miles northwest of Murfreesboro, Murfrees-
boro (15’) Quadrangle.

Discussion.—This species is characterized by its smooth posterior half or three-
quarters and the indistinct nature of the costae on its flanks and in the sulcus.
The species is unlike C. immatura in having more costae and in having some of

574 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

them occupying the median sulcus. It is quite unlike C. minuta, another small
species, in the uncertain character of the costae. No other species are comparable.

CAMERELLA OBESA Cooper, new species
Plate 116, D, figures 25-34

Shell of about medium size for the genus, slightly wider than long and with
the greatest width anterior to the middle; outline subpentagonal; apical angle
about 100°. Sides narrowly rounded; anterolateral margins short, sloping
strongly toward the middle; valves unequally convex, the brachial valve having
the greater convexity. Surface mostly smooth, but anterior extension of tongue
marked by 2 costae, anterior end of fold marked by 3 short costae, and anterior
surface of flanks by 2 costae.

Pedicle valve gently convex in lateral profile and broadly but slightly convex
in anterior profile ; umbonal and median regions gently inflated ; sulcus short and
shallow, defined by 2 short anterior folds; tongue bent at a right angle, long,
serrate, and with a truncated front; beak short.

Brachial valve fairly strongly convex in lateral profile but strongly domed in
anterior profile ; median region and umbo swollen; fold short and inconspicuous ;
flanks swollen and with precipitous sides.

Measurements in mm.—Holotype, length 9.6, brachial length 9.1, width 10.7,
hinge width 2.1, thickness 8.3.

Types.—Holotype: 117140a; unfigured paratype: 117140b.

Horizon and locality—Rockland formation in New York: On Mill Creek,
Turin, Port Leyden (15’) Quadrangle.

Discussion.—This species is like a small C. volborthi in its noncostate posterior
and its obese form, but it is a much smaller species having a wider and squarer
tongue on the pedicle valve. It is larger and ornamented by stronger costae than
C. tumida from Newfoundland. Camerella obesa is similar to C. ventricosa from
the Crown Point formation but differs in having a more strongly geniculated
tongue and less strong costae.

CAMERELLA OKLAHOMENSIS Cooper, new species
Plate 71, F, figures 27-35

Shell of about medium size for the genus, slightly wider than long; brachial
valve deeper than the pedicle valve; apical angle approximately a right angle;
widest at the middle; surface semicostate, 3 costae on the fold, 2 in the sulcus,
and 4 to 5 on the flanks.

Pedicle valve moderately convex in lateral profile with a bulge just posterior
to the middle ; anterior profile gently convex ; sulcus originating abruptly a short
distance anterior to the middle; sulcus narrow, moderately deep; tongue short;
median region swollen; flanks narrowly rounded and with steep slopes.

Brachial valve strongly convex in lateral profile, strongly domed in anterior
profile. Median region and flanks swollen and tumid. Fold low, short, originat-
ing anterior to the middle. Lateral slopes precipitous.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 575

Measurements in mm.—Holotype, length 9.2, brachial length 8.5, width 10.2,
hinge width 2.6, thickness 7.5.

Type.—Holotype: 117993.

Horizon and locality.— Bromide formation (Pooleville member—5o feet below
the top) in Oklahoma: 0.1 mile southeast of the Observation Point on the Scenic
Drive to Falls Creek, about I mile southeast of U. S. Highway 77, Murray
County.

Discussion.—This species is one of the partly costate species and is character-
ized by 2 costae in the sulcus and 3 on the fold. It is suggestive of C. plicata
(Schuchert and Cooper) but is a wider form with a somewhat wider apical angle.
It is more strongly costate than C. obesa and C. ventricosa.

CAMERELLA PARVA Billings

Camerella parva Bituincs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 210, 1865.

Types.—G.S.C.
Horizon and locality—Table Head series (Logan’s divisions N, P) in New-
foundland: 4 miles northeast of Portland Creek.

CAMERELLA PENNSYLVANICA Cooper, new species
Plate 118, E, figures 45-49

Shell of about medium size for the genus, subpentagonal in outline; length and
width about equal; posterolateral margins straight, forming an angle of 96°;
sides rounded; maximum width at or near the middle; anterior margin trun-
cated ; anterolateral margins short, gently curved. Surface paucicostate, posterior
third smooth, anterior two-thirds costate, 4 costae on the fold, 3 in the sulcus,
and 2 to 3 costae on the flanks.

Pedicle valve less deep than the brachial one, moderately and fairly evenly con-
vex ; anterior profile moderately convex ; umbonal and median regions inflated ;
sulcus originating at about the middle, shallow and wide; tongue short, rounded ;
flanks narrow, moderately swollen, and with steep slopes. Beak short and
incurved.

Brachial valve moderately convex but considerable curvature in the anterior
half; anterior profile forming a highly convex dome with precipitous sides. Beak
narrow; umbo and median region somewhat swollen; fold low and following
closely the curve of the lateral profile; flanks fairly strongly swollen.

~ Measurements in mm.—Holotype, length 10.8, brachial length 10.1, width 10.8,
hinge width 1.6?, thickness 7.9.

Type.—Holotype: 117142.

Horizon and locality—Top of cherty beds in upper Row Park formation in
Pennsylvania: In the field east of the railroad cut and on the north side of the
Cumberland Valley RR., about 2 miles southwest of Marion, Chambersburg
(15’) Quadrangle.

Discussion.—This species is a partially costate form with obvious similarities
to C. plicata (Schuchert and Cooper) but the apical angle is greater, the fold is

576 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

less prominent, and the sulcus is shallower. This species is unlike any other de-
scribed Marmor Camerella. It is larger than, and ornamented differently from,
C. ventricosa of the Crown Point limestone. The fold and sulcus are wider and
deeper in C. pennsylvanica than in the type specimen of C. varians.

CAMERELLA PERPLEXA Cooper, new species
Plate 115, A, figures 1-5; plate 115, B, figures 6-11

Shell of fairly large size for the genus, length and width about equal; outline
subpentagonal ; posterolateral extremities long and straight forming an angle of
92°; sides narrowly rounded; anterolateral extremities short and oblique toward
the middle; anterior truncate; anterior commissure broadly uniplicate; valves
unequally convex, the brachial valve having the greater depth. Surface costate,
in the anterior four-fifths ; umbonal region of both valves smooth; costae strong,
angular, 4 on the fold, 3 in the sulcus, and 4 on the flanks.

Pedicle valve gently convex in lateral profile; broadly and gently convex in
anterior profile; umbo somewhat swollen; sulcus originating about 4 mm. an-
terior to the beak, shallow in the median region but becoming deep at the anterior
margin. Tongue only moderately geniculated, moderately long, and truncated.
Flanks narrowly rounded and swollen and with steep lateral slopes. Beak mod-
erately long.

Brachial valve moderately convex in lateral profile but strongly and roundly
domed in anterior profile. Umbo moderately convex; median region swollen;
fold wide and fairly strongly elevated in its anterior third. Flanks swollen and
with precipitous sides.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
1513) C0. 2 lm RE em reap 11.8-+ II.2 12.2 2.8 8.5
Figured specimen ............. 12.8+ 11.6 13.1 3.5 9.0

Type.—Holotype: 117143; figured specimen: I11123.

Horizon and locality—Elway formation, in Tennessee: $ mile north of Eidson,
Kyles Ford (T.V.A. 170-SE) Quadrangle.

Same formation in Virginia: East of Moccasin Creek on Virginia County
Highway 679, # mile south of Tumbez, Moll Creek (T.V.A. 196-SE) Quad-
rangle.

Discussion.—This species is characterized by its erect form, strongly defined
costae, and the presence of 3 costae in the fold and 4 on the sulcus. It differs
from C. globularis from the Whistle Creek formation in its less convex valves
and more erect beak. It differs from C. multiplicata, also of the Elway forma-
tion, in the less numerous costae and more robust shell. Its form is somewhat
like C. quadriplicata, but it is not so robust and the details of the ornamentation
are different.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 577

CAMERELLA PLICATA (Schuchert and Cooper)
Plate 114, A, figures 1-24

Rhynchocamara plicata ScHUCHERT and Cooper, Amer. Journ. Sci., vol. 22, p. 248, 1931;
Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 189, pl. 25, figs. 1, 2, 17, 18 (not 7), 1932.

Shell of about medium size for the genus, somewhat triangular in outline,
generally wider than long or with length and width nearly equal; greatest width
about two-thirds the length from the beak. Angle formed by posterolateral mar-
gins slightly less than a right angle; anterolateral extremities narrowly rounded ;
front subtruncate. Posterior third to two-thirds of shell smooth, front half marked
by narrowly rounded costae with interspaces about equal to width of costae, 2 oc-
cupying the sulcus, 3 the fold, and 3 to 4 marking the flanks. An occasional
extra costa appears in the sulcus and a corresponding one on the fold.

Pedicle valve gently convex and with the maximum convexity in the posterior
third. Sulcus originating at about the middle, shallow and occupying about half
the width. Tongue short, truncated. Flanks slightly convex, slopes fairly steep.
Median and umbonal parts slightly inflated. Spondylium long and deep.

Brachial valve moderately convex in lateral profile, nearly semicircular in an-
terior profile ; about twice as deep as the pedicle valve. Fold low, in some speci-
mens scarcely distinguishable from the body of the shell. Flanks moderately
convex and with steep slopes. Median part somewhat inflated. Cruralium short,
shallow, and narrow.

Measurements in mm.—

Brachial
Length length Width Thickness

Fiynotype \GEUSIAZC) since. fies sitesi 10.8 10.0 10.9 8.3
a GREASY ic. ia ctycinoiy tas see 10.6 10.0 10.7 7.9
“ CEE TEAA) isso es osad yaidiecigee 10.5 9.9 10.5 7.7
a (TIPT3O9))) A AS ee 90.5 9.0 10.4 VLE-

Types.—Lectotype: Y.P.M. S2035 ; figured hypotypes : 111139d,g, I11147a-c;
measured hypotypes: II11143a, 117144.

Horizon and locality.—Ridley formation in Central Basin of Tennessee: At
Nice’s (Ward’s) Mill, on Stone River, 8 miles (airline) northwest of Murfrees-
boro; at Murfreesboro; Stone River Bridge on Tennessee Highway 96, 1 mile
west of Murfreesboro; east side of Marshall Knobs, 5 miles south of Murfrees-
boro; Rutherford County ; vicinity of Nashville, Nashville (15’) Quadrangle.

Wardell formation in Tennessee: In the Hesperorthis zone on U. S. High-
way 25E, 4 mile northeast of Indian Creek, Evans Ferry section, Howard Quar-
ter (T.V.A. 162-NW) Quadrangle; 1.1 miles northeast of Lee Valley and at
Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

Discussion.—This species is variable but in general consists of partially plicate
forms having 2 costae in the sulcus and a length and width about equal. The
species suggests the bicostate form of R. edmundsom but generally is not com-
pletely costate as in that form. It is very suggestive of C. pennsylvanica but
has fewer costae in the sulcus and has a more strongly convex brachial valve.

578 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

CAMERELLA POLITA Billings
Camerella polita B1ttines, Geol. Surv. Canada, Paleozoic fossils, vol. 1, pp. 304, 305, fig. 207,
1865.
Rhynchocamara polita (Billings) UtricH and Cooper, Geol. Soc. Amer. Special Pap. 13,
p. 251, 1938.

Types.—G.S.C.
Horizon and locality—Mystic conglomerate, in Quebec, Canada: In Range 6,
Lot 20, Stanbridge Township.

CAMERELLA ? PRIMIGENIA (Bradley)
Plate 109, G, figures 32-38

Anastrophia primigenia BravLey, Contr. Walker Mus., vol. 2, No. 6, p. 228, pl. 23, figs. 9-12,
1930.

This species is a peculiar completely costate type of Camerella rather than an
Anastrophia. Members of the latter genus usually have a well-marked fold and
sulcus. But Bradley’s species is characterized as having the fold and sulcus visi-
ble chiefly at the anterior commissure. A section of the interior of a brachial
valve showed the characteristic cruralium of the Camerellidae and failed to show
the peculiar alate plates that are diagnostic of Anastrophia. The species is there-
fore best placed in Camerella until its true affinites can be determined.

Types——Figured hypotypes: 111175a,b, 111177.

Horizon and locality—Kimmswick formation in Arkansas: About 24 miles
above the mouth of Cave Creek, 7 to 8 miles northwest of Batesville, Batesville
(30’) Quadrangle.

CAMERELLA PULCHRA Cooper, new species
Plate 114, B, figures 25-34; plate 116, E, figures 35-39; plate 116, F, figures 40-46

Shell of about medium size for the genus, longer than wide and with an elongate
triangular outline; posterolateral margins long, forming an angle of about 80°.
Greatest width in the anterior third and with narrowly rounded sides; anterior
truncated. Anterior commissure somewhat narrowly but not strongly uniplicate.
Surface costate except for smooth umbones; 3 costae on fold, 2 (occasionally 3)
costae in sulcus, and 3 on the flanks.

Pedicle valve gently but unevenly convex in lateral profile, the most convex
part just posterior to the middle. Anterior profile fairly strongly convex ; umbonal
region swollen ; sulcus originating on the anterior side of the umbo just posterior
to the middle; sulcus shallow and narrow throughout its length; flanks narrowly
convex and with steep sides.

Brachial valve having a greater depth than the pedicle one, moderately con-
vex in lateral profile ; strongly convex in anterior profile; umbonal and median
regions swollen; fold conspicuous in the anterior half but not strongly elevated ;
fold narrow ; flanks narrowly rounded and having steep slopes.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 579

Measurements in mm.—
Brachial Hinge
Length length Width width Thickness

Efototyne tet: figs da O84. 05.4 10.0 0.5 9.0 32 7.2
Paratype Ga1r46b).....04...... 9.4 9.3 9.0 3.0 7.6
= (ratia6e)...644.. 2... 10.0 9.5 9.3 3.2 UA

Types —Holotype: 111146a; figured paratypes: 85340a, 111146b,c, 118012;
unfigured paratypes: 85340b, 111146d,e.

Horizon and locality—Ridley formation in Rutherford County, Tenn.:
C. St. L. and N. RR., 34 miles northwest of Murfreesboro; Murfreesboro ; Nice’s
(Ward’s) Mill on Stone River, 8 miles (airline) northwest of Murfreesboro,
34 miles northwest of Murfreesboro.

Discussion.—This species is characterized by its seminude exterior, the pos-
terior half being without ornamentation but the anterior half strongly costate,
and the shell generally elongate. It is strongly suggestive of C. edmundsoni in
its elongate form, but the latter species is nearly completely costate. Its elongate
form distinguishes C. pulchra from any of the Elway Camerellas except C. mul-
tiplicata, but that species is more finely and numerously costate.

CAMERELLA QUADRIPLICATA (Willard)
Plate 111, B, figures 16-26

Camarotoechia quadriplicata WILLARD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 291, pl. 2, fig. 14, 1928.

Shell of about medium size for the genus, subtriangular to subpentagonal in
outline, length and width approximately equal; beak angle about 100°, defined
by slightly concave posterolateral margins; anterolateral extremities narrowly
rounded, situated in the anterior third, and forming the greatest shell width.
Anterior margin slightly rounded. Surface costate, 2 to 4 costae in the sulcus,
3 to 5 on the fold, and 5 or 6 on the flanks. Costae and interspaces covered by
a felt of small granules.

Pedicle valve moderately convex in lateral profile and slightly convex in an-
terior profile. Sulcus originating about 4 mm. anterior to the beak in front of
a gently convex umbo. Sulcus, widening anteriorly to occupy very slightly more
than half the width at the front margin. Tongue short and abruptly truncated
anteriorly. Flanks flattened adjacent to the sulcus but narrowly rounded at the
margins to form steep posterolateral slopes. Delthyrium narrow, beak not elon-
gated. Spondylium deep.

Brachial valve moderately convex and with a well-rounded umbo in lateral
profile ; narrowly convex and deeper than the pedicle valve in anterior profile.
Umbo slightly swollen; fold low and gently rounded in profile. Flanks mod-
erately depressed below the fold, well rounded and with steep lateral slopes.

Interior with spondylium and cruralium as usual in the genus.

580 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial
Length length Width Thickness
Fiypotype. A LITISZR) os 6. wept. «ne Bre? 10.8 13.0 8.0
ie (TITTEA). Sgeee. ae 13.7 12.5 14.0 9.6 ?
o (BUDUSHOR 235 cap iie ay 14.2 13.3 15.4 9.5

Types.—Figured hypotypes: 111155b, 111156a, 111157a,c, 118011a; measured
hypotype: I11157b.

Horizon and locality.—Lincolnshire formation (Hogskin member) in Ten-
nessee: 2.1 miles southwest of Mount Eager Church, Hogskin Valley, Powder
Springs (T.V.A. 154-SW) Quadrangle ; Sally Cleveland Farm, ¢ mile southwest
of Washburn, Dutch Valley (T.V.A. 154-SE) Quadrangle; Evans Ferry; 3 mile
east-northeast of Red Hill, 4 miles west-southwest of Thorn Hill, Avondale
(T.V.A. 162-SW) Quadrangle.

Lincolnshire formation in Tennessee: Near Marble Bluff, 8 miles west-north-
west of Loudon, Loudon (30’) Quadrangle.

Discussion—Some forms of this species very closely resemble C. bicostata
but differ therefrom in the presence of the minute granules, more numerous costae
on the flanks, and the fact that the costae extend farther posteriorly toward the
beak than in C. bicostata, in which the posterior half of the shell is generally
smooth.

Willard originally referred this shell to Camarotoechia, and the presence of the
granules are suggestive of some of the species originally called Camarotoechia
in the Ordovician. Granules are present in some species of Rostricellula but are
rare or hitherto unnoticed on members of the genus Camerella. In fact C. quad-
riplicata is the only Camerella noticed in this book which has granules.

CAMERELLA TENNESSEENSIS Cooper, new species
Plate 115, D, figures 22-31

Shell small with length and width about equal; outline subtriangular ; apical
angle 100° ; sides rounded; anterior truncated ; anterior commissure broadly and
gently uniplicate. Posterior half smooth, anterior half costate, 5 costae in the
sulcus, 6 on the fold, and 5 on the flanks.

Pedicle valve gently convex in lateral profile and with the maximum con-
vexity in the median region ; anterior profile gently convex in the median region
but the sides dropping steeply and abruptly ; umbonal and median regions swol-
len ; sulcus originating slightly anterior to the middle, wide and shallow. Tongue
short and broadly rounded. Flanks narrowly rounded. Beak short, lying an-
terior to the brachial umbo.

Brachial valve moderately convex in the median region but with strongly
curved umbo and anterior ; strongly convex in anterior view and with precipitous
sides. Median and umbonal regions swollen; fold slightly elevated; flanks nar-
rowly rounded.

Measurements in mm.—Holotype, length 7.6, brachial length 7.9, width 7.9,
hinge width 2.8, thickness 6.1.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 581

Type.—Holotype: 111160.

Horizon and locality—Middle part of Arline formation in Tennessee: On
north side of wagon road in cedar glade, 4 mile southeast of Friendsville, Con-
cord (T.V.A. 138-SW) Quadrangle.

Discussion.—This species is unlike any other Camerella known from the Appa-
lachian region. It is characterized by the strongly arched umbonal region of the
brachial valve so that the length of that shell is actually greater than that of the
pedicle valve. In this respect the species resembles certain Canadian, Mystic,
and Pogonip forms such as C. breviplicata Billings, C. arkansasensis (Ulrich
and Cooper) and C. sublaevis (Ulrich and Cooper). It differs from all these in
its possession of a broad fold having 6 costae, with 4 on the flanks.

CAMERELLA TRIANGULATA Cooper, new species
Plate 110, F, figures 22-35

Shell of about medium size for the genus, greatest width in the anterior portion ;
outline subtriangular; apical angle about 80°; length and width about equal;
valves subequal in depth. Surface smooth except for strong costae in anterior
third ; 2 costae in the sulcus, 3 on the fold, and 1 on the flanks.

Pedicle valve moderately convex in lateral profile and with the maximum con-
vexity slightly posterior to the middle; anterior profile broadly and gently con-
vex ; umbo and median region swollen; sulcus originating at about the middle;
sulcus wide and shallow. Tongue long, truncated on the front.

Brachial valve unevenly convex in lateral profile, with the maximum convexity
near the middle. Anterior profile strongly convex with steep sides. Umbo nar-
rowly swollen ; median region inflated ; fold narrow, moderately elevated at front ;
flanks narrowly rounded, terminating in a narrowly rounded lobe.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Lnlai ho) ra DR oe a ee ae 8.5 8.0 8.2 1.8 6.3
CON ci viene eerie sig Ag acts 15.10 8.3 7.0 7.8 Hig 5.0

Types.—Holotype: 111162; figured paratype: 117145.

Horizon and localhity—Lenoir formation (shaly beds above Valcourea zone)
in Tennessee: Billingsaria zone, $ and 1 mile northeast of Friendsville, Concord
(T.V.A. 138-SW) Quadrangle; Knoxville; in front of church in center of
Mosheim, Mosheim (T.V.A. 181-NW) Quadrangle; quarry on west side
U. S. Highway 11, 14 miles southwest of Philadelphia, Philadelphia (T.V.A.
131-NW) Quadrangle.

Discussion —This species is characterized by its elongate-triangular outline
and the few strong but short costae located at the front margin. It suggests
C. varians of the Mingan and Crown Point formations but differs from that
species in having a less convex brachial valve and much stronger costae at the
front margin. No other Appalachian species is like this one.

582 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

CAMERELLA TUMIDA Cooper, new species
Plate 111, D, figures 36-40

Shell small for the genus, globular in outline and profile; length, width and
thickness nearly equal ; apical angle between 90° and 100°; sides rounded; front
margin truncated; surface finely costate in the anterior half but smooth on the
posterior half; 4 costae on the fold, 3 in the sulcus, and about 4 on the anterior
side of the flanks.

Pedicle valve with almost same depth as the brachial valve, moderately con-
vex in lateral profile with a moderate bulge just posterior to the middle; umbo
and median region inflated; sulcus originating at about the middle, shallow;
tongue narrow, long and narrowly rounded, bent at right angles in a broad curve.
Flanks narrowly rounded and with steep slopes. Beak strongly incurved.

Brachial valve nearly flat in the median region in lateral profile but with the
front truncated and the umbo inflated ; anterior profile forming a narrowly curved
dome with a flattened top but with precipitous sides. Fold confined to the an-
terior half where it is moderately elevated. Flanks narrowly rounded.

Measurements in mm.—Holotype, length 7.1, brachial length 6.4, width 7.0,
hinge width 2.0?, thickness 6.1.

Type.—Holotype: 117146.

Horizon and locality.—Table Head series (middle to lower) in Newfound-
land: On Lower Head, 4 miles north of Cow Head.

Discussion—This species is a small, compact form having most of the shell
smooth. It is truncated at the front end and has a long, strongly geniculated
tongue. It is somewhat like C. obesa but is more finely costate. It is also sug-
gestive of Camerella ventricosa, but that species is larger and the tongue is not
so strongly geniculated and the costae are stronger.

CAMERELLA UMBONATA Cooper, new species
Plate 108, G, figures 33-39

Shell of about medium size for the genus, length and width about equal ; sub-
circular in outline; sides somewhat rounded and front nearly straight; apical
angle nearly 120°. Brachial valve considerably deeper than the pedicle one.
Posterior half smooth, anterior half costate, 4 costae on the fold, 3 in the sulcus,
and 2 on the flanks.

Pedicle valve shallow, nearly flat in lateral profile ; anterior profile nearly flat ;
umbo gently inflated ; sulcus originating at the middle, broad and shallow ; tongue
long and broadly truncated; flanks narrow and flattened but with their antero-
lateral edges deflected away from the commissure; beak low and broad, slightly
depressed and not protruding to the level of the umbo.

Brachial valve moderately convex but depressed anteriorly and with the umbo
strongly swollen; anterior profile narrowly domed and with precipitous sides.
Umbo and median region strongly inflated; fold prominent only in the anterior
third where it is somewhat rounded in profile; flanks narrowly rounded.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 583

Measurements in mm.—Holotype, length 8.1, brachial length 8.0, width 8.7,
hinge width 2.6, thickness 6.4.

Type.—Holotype: 117147.

Horizon and locality—vYellow limestone on 25-foot sandstone at base of
Eureka group in Nevada: 34 miles N. 17° E. of Martin Ranch, Roberts Moun-
tains (1°) Quadrangle.

Discussion.—This species is somewhat like C. tennesseensis in having a
strongly swollen brachial valve. It has 3 costae in the sulcus which is unusually
wide. The species has the form of Perimecocoelia or Parastrophina, but the
cruralium as seen when the shell is wet seems to be short and small like that of
Camerella. This species is most like C. virginiensis but differs in having a more
tumid brachial valve, a more prominent fold, and a deeper sulcus.

CAMERELLA UNICOSTATA Cooper, new species
Plate 113, B, figures 6-9

Shell small, suboval in outline with the length slightly greater than the width.
Greatest width at about the middle. Beak angle about 100° formed by slightly con-
vex posterolateral margins. Lateral and anterior margins fairly strongly convex.
Posterior half smooth, anterior half costate with a single costa occupying the
sulcus, 2 costae on the fold, and 2 and an incipient third marking the flanks.

Pedicle valve with lateral profile gently convex; broadly convex in anterior
profile. Posterior half gently convex; sulcus originating about 4 mm. anterior
to the beak, abrupt, shallow, occupying less than half the width at the front
margin. Costa bounding sulcus elevated above the others, narrowly rounded.
Flanks narrowly rounded with steep lateral slopes.

Brachial valve more strongly convex than the pedicle one in lateral profile ;
strongly arched in anterior profile. Fold low and narrow, defined only at the
front where it makes a small anteriorly projecting lobe. Flanks narrowly rounded
with steep lateral slopes.

Measurements in mm.—Holotype, length 5.4, brachial length 4.9, width 5.0,
thickness 4.0.

Type.—Holotype: 111161.

Horizon and locality.—Ward Cove formation in Tennessee: 2 miles south of
Hall Crossroad, south of Hickey place, Fountain City (T.V.A. 146-SW)
Quadrangle.

Discussion——This species is of about the size and shape of C. minuta but
differs in the possession of a single costa in the sulcus, a more oval outline, and
less costate flanks.

CAMERELLA VARIANS Billings

Plate 110, B, figures 6, 7; plate 110, D, figures 12-15; plate 110, E, figures 16-21;
plate 118, F, figures 50-54

Camarella varians Brtuincs, Canadian Nat. Geol., vol. 4, p. 445, fig. 24, 1859; Geol. Canada,
p. 127, fig. 52, 1863—Raymonp, Ann. Carnegie Mus., vol. 7, No. 2, pp. 250-253, pl. 36,
figs. 25, 26, IQIT.

584 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

(?) Rhynchocamara varians (Billings) TWENHOFEL and WHITING, Geol. Soc. Amer. Special
Pap. II, p. 53, pl. 7, figs. 19-21, 1938.

The type lot of this species consists of two specimens: a fairly large one and
a smaller one. The former has the length and width about equal; apical angle
about 90° and the valves subequal in depth, the brachial valve somewhat deeper
than the pedicle one. The sulcus is moderately wide but with a short tongue.
The sulcus originates at about the middle and is occupied by 3 moderately strong
costae that do not extend posteriorly as far as the place of origin of the sulcus.
One or two short and faint costae occupy the flanks. The brachial valve has a
low fold originating anterior to the middle and marked by 4 short costae. The
flanks are marked by 1 or 2 indistinct costae. The brachial valve is moderately
swollen and moderately convex in lateral profile. This specimen (G.S.C. 1038)
is selected as the type of the species.

The second specimen is smaller and more elongate and has only 2 costae in
the sulcus and 3 on the fold. It is probably a young form of the species, but not
enough specimens of C. varians have ever been collected to make possible a study
of its variation.

Types.—Lectotype: G.S.C. 1038; figured paratype: G.S.C. 1038a; figured
hypotype: 111163; Y.P.M. 15284.

Horizon and locality—Lower half of the Mingan formation in the Mingan
Islands: St. Lawrence River on Parroquet, Eskimo, Bald, Mingan, and Nia-
pisca Islands and on Clearwater Point. Twenhofel and Whiting’s specimen is
from Eskimo Island. Twenhofel states that the species is common only on
Mingan Island. It is not possible to tell from the description whether or not more
than one species is included in the collections.

Crown Point formation in New York: On Valcour Island, Lake Champlain,
Plattsburg (15’) Quadrangle.

Discussion.—Camerella varians has been fairly widely identified in rocks
hitherto classified as Chazyan. The references to this species in the Table Head
series of Newfoundland are probably wrong. The species is said to come from
East Tennessee, but several specimens from that area so referred are here as-
signed to the new species C. triangulata. Specimens from the Crown Point lime-
stone near Chazy identified by Dr. P. E. Raymond are also referred to a new
species (C. ventricosa). The Mingan specimens and a few from the New York
Chazy rocks are believed to belong to C. varians. See the above-mentioned
species for comparisons.

CAMERELLA VENTRICOSA Cooper, new species
Plate 110, G, figures 36-49
Camarella varians RayMonp, (not Billings), Ann. Carnegie Mus., vol. 7, p. 250, pl. 36,
figs. 19-23 (not 24-28), 33-36 (doubtful), 1911.

Shell variable, generally somewhat broadly triangular to subpentagonal in out-
line ; length equal to, greater than, or less than the width; apical angle varying
from 75° to about 100° ; paucicostate, the posterior half generally smooth but the

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 585

anterior half costate ; fold generally with 3 costae, sulcus with 2, and flanks with
I or 2 depending on age.

Pedicle valve slightly less deep than the brachial one, moderately convex in
lateral profile and with the maximum convexity slightly posterior to the middle;
anterior profile broadly and gently convex; umbonal and median regions swol-
len, the maximum swelling just posterior to the sulcus; sulcus originating at the
middle, wide and shallow; tongue long, its angle of geniculation not quite reach-
ing a right angle; flanks narrowly rounded; beak fairly long and strongly
incurved.

Brachial valve fairly strongly convex in lateral profile ; anterior profile strongly
domed and with precipitous sides. Umbo and median areas strongly swollen;
fold originating at the middle, partaking of the general profile and only moder-
ately elevated at the front. Flanks narrow and swollen.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
BU UGE IE Me ox jaja aiecs wo, 56.6 g's s 3) 0'hys 9.8 8.7 10.1 3.1 8.0
Paratyoe. (PELTFZOD) oc cc sos aes es 8.2 7.4 9.0 > 6.0
ot ar Ly, Mn alan a 9.5 8.7 8.7 ? 6.7
i (zaer70d) PI. 8.8 78 G 2.8 6.9

Types.—Holotype: 111170a; figured paratype: 111170d ; unfigured paratypes:
I11170b,c.

Horizon and locality—Crown Point formation (loose but from Brainerd and
Seely’s section 2, zone 3 of Division B) on Plattsburg (15’) Quadrangle, New
York: At Chazy; at the normal school 4 mile north of Plattsburg; Valcour
Island.

Discussion.—This species is characterized by its compact form, the strongly
geniculated pedicle tongue, the anteriorly costate and posteriorly nude exterior,
and strong convexity. The species suggests C. obesa from the Trenton (Rock-
land) limestone, but the tongue is less geniculated and the costae extend farther
posteriorly on the valves. It is also similar to C. oklahomensis, but it is larger
and more convex although less strongly costate. Camerella ventricosa is a larger
and more strongly costate species than C. tumida from Newfoundland.

CAMERELLA VOLBORTHI Billings
Plate 110, C, figures 8-11; plate 116, A, figures 1-5

Camarella volborthi Brrtines, Canadian Nat. Geol., vol. 4, p. 301, 1859; Geol. Canada, p. 143,
fig. 77, 1863 Hai and Crarke, Pal. New York, vol. 8, pt. 2, p. 220, pl. 62, figs. 13-18
(not 11 and 12), pl. 84, fig. 42, 1894.—Mutter, North Amer. Geol. Paleont., p. 338,
fig. 546, 1889—ScHucHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1,
pl. 25, figs. 5, 20-22, 28-30, 1932.

This is one of the largest species of the genus now known. It may be recog-
nized by this fact and by its almost completely smooth exterior. Costae are con-
fined to the margins of the valves and are generally not strongly developed.

Types——Lectotype: G.S.C. 1148a; paratype: G.S.C. 1148b; figured hypo-
type: 117148a; hypotype: G.S.C. not numbered.

586 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality.—Cloche Island member of the Rockland formation in
Ontario, Canada: South of Helen Lake, La Cloche Island, Manitoulin District.
Rockland formation in Ontario, Canada: At Paquette Rapids.

CAMERELLA sp. 1
Plate 106, A, figures 1-5

Shell large for the genus, wider than long, subtriangular to subpentagonal in
outline ; variable ; paucicostate with the fold having 3 costae and the sulcus 2 or
3; flanks with 2 to 4 costae; posterior half smooth.

Pedicle valve with gentle convexity to the lateral profile and slight convexity
to the anterior profile. Umbonal region flatly convex, sulcus originating at the
middle, deep and moderately wide; flanks flattened.

Brachial valve moderately convex in lateral profile; strongly convex in lateral
profile; umbonal and median regions moderately swollen; fold originating at the
middle, moderately elevated, somewhat narrow. Flanks moderately swollen and
with steep slopes.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
DLFUAOG Lt we OE, Aa II.5+ 10.9 12.1 3.5 8.1
WEZLAQD 2 a Ate aOR eh 12.90+ T22 16.9 27 8.7

Figured specimen.—117149d ; measured specimen: 117149b.

Horizon and locality.—Low in the Benbolt formation in Tennessee: 0.1 to 0.2
mile north of the road, 1.1 miles northeast of Lee Valley, Lee Valley (T.V.A.
171-NW) Quadrangle.

Discussion—This species suggests bicostate examples of C. quadricostata
(Willard) from the Hogskin member of the Lincolnshire formation. It appears
to be wider and to have more narrowly rounded lateral margins than the Hogskin
species.

CAMERELLA sp. 2
Plate 112, F, figures 30-33

Three poorly preserved specimens, probably immature individuals. Small,
paucicostate and narrowly lenticular in both profiles. There are 2 costae in the
sulcus, 3 on the fold, and 3 on the flanks. Fold and sulcus originating at the
middle, the former narrow and short, the latter shallow.

Measurements in mm.—117150a, length 7.8, brachial length 6.9, width 8.3,
thickness 4.3.

Figured specimens.—117150a,b.

Horizon and locality—Blackford formation (basal conglomerate zone) in
Virginia: Just north of the junction of Virginia Highways 100 and 42, Staffords-
ville, Giles County.

CAMERELLA sp. 3

Plate 117, C, figures 13-18

Small, probably immature because of the slender profile; subtriangular in out-
line ; paucicostate, the posterior two-thirds smooth, the anterior third costate

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 587

with 2 costae in the sulcus, 3 on the fold, and 1 on the flanks. Pedicle valve
flatly convex in both profiles; sulcus originating two-thirds the length from the
beak, broad and shallow ; brachial valve deeper than the pedicle one and probably
more convex ; fold weathered away but apparently fairly wide and low as indi-
cated by the pedicle tongue.

Figured specimen.—117151.

Horizon and locality.—Yellow beds above the 25-foot sandstone in Nevada:
On the saddle just north of hill 8167, Martins Ridge, Monitor Range, Roberts
Mountains (1°) Quadrangle.

CAMERELLA sp. 4
Plate 121, FE, figure 14

A single brachial valve indicates a species of Camerella different from others
described herein. The specimen is 6.2 mm. long and 6.6 mm. wide. It is mod-
erately convex in both profiles. The fold is low and margined by 2 costae
that extend to about the middle. Between these costae the fold is gently de-
pressed. The flanks are marked by 2 costae. The obscure costae appear in the
depression bounded by the costae of the fold.

Figured specimen.—123294.

Horizon and locality—Whitesburg formation in Tennessee: 14 miles west of
Bulls Gap, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Genus IDIOSTROPHIA Ulrich and Cooper, 1936

Idiostrophia UtricH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 631, 1936; Geol. Soc.
Amer. Special Pap. 13, p. 249, 1938.

This genus is most readily recognized by its triangular form. It is not com-
mon in any of its known occurrences. Previous to the present writing it was
known only from boulders of the Mystic conglomerate which correspond in age
to part of the Table Head series of Newfoundland. Several new species are
added here which extend the geographic range to Nevada and Newfoundland.

The triangular form is not the only peculiar external character of the genus. It
has a peculiar type of folding which may be characterized as broadly uniplicate.
In Camerella a well-marked fold is generally present, and the flanks bounding
fold and sulcus are fairly wide and prominent. In Idiostrophia the flanks bound-
ing the sulcus are narrow folds, generally with an angular ridge facing outward
and connecting with the beak. At its anterior extremity this fold generally ter-
minates in a narrow lobe. The lateral lobes correspond to the flanks of the
camerellid which bound the sulcus. Thus the broad and often somewhat swollen
area between the lateral folds corresponds to the sulcus of the camerellid.

In the brachial valve the steeply sloping side is usually more or less deeply
concave and forms a broad fold facing outward. At the anterior end of the fold
a projection of considerable size, such as that in J. nuda, extends toward the
pedicle valve and unites with it at the anterior point where the pedicle lateral
plication dies out and the pedicle tongue is given off. At this point the pedicle
valve is very shallow. The space between the brachial lateral ridges is thus the

588 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

brachial fold. The uniplication of these shells is thus obscure but definite never-
theless.
IDIOSTROPHIA COSTATA Ulrich and Cooper

Plate 100, B, figures 9-13

Idiostrophia costata Utricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 250, pl. 56C,
figs. 4-6, 9-11, 1938.

Type.—Holotype : 92886.
Horizon and locality—Boulder in Mystic Conglomerate in Quebec, Canada:
Range 6, Lot 20, Stanbridge Township.

IDIOSTROPHIA NUDA Cooper, new species
Plate 100, E, figures 21-29

Shell of about medium size for the genus, length and width nearly equal, out-
line triangular ; sides obliquely straight ; anterior margin broadly rounded; valves
unequally convex, the brachial valve having the greater depth; anterior commis-
sure broadly uniplicate ; surface of posterior four-fifths smooth; anterior margin
marked by about 12 costae.

Pedicle valve moderately convex in lateral profile; broadly convex in anterior
profile; umbonal region swollen; median region inflated but not so strongly in-
flated as the umbo; lateral region with a long, shallow depression marking a
deflected area which defines a ridge extending from beak to slightly anterior to
middle ; side grooved between ridge and lateral commissure. Tongue wide.

Brachial valve unevenly convex in lateral profile with the umbonal region
swollen and extending to the level of the beak of the pedicle valve; anterior com-
missure narrowly convex; median region swollen; sides precipitous, with a
groove parallel to the lateral commissure ; anterior forming a broad fold occupy-
ing the entire width; anterolateral extremities produced into a short flange that
fits into a slot at the posterior of the tongue of the pedicle valve.

Interior unknown.

Measurements in mm.—Holotype, pedical length 10.4, brachial length 10.3,
midwidth 9.1, anterior width 10.8, thickness 7.8.

Type.—Holotype: 117170.

Horizon and locahty.—Pogonip group (mottled zone 700 feet below the Eureka
quartzite) in Nevada: At the base of the first ridge east of Frenchman Flat, Las
Vegas (1°) Quadrangle.

Discussion.—This species is characterized by its fairly strongly inflated valves
and the lack of ornamentation on the posterior four-fifths. The costellae along
the front margin are also fairly delicate. The species is thus unlike any of those
described herein.

IDIOSTROPHIA PAUCICOSTATA Cooper, new species
Plate 109, D, figures 18-20

Shell of about medium size for the genus, triangular in outline; sides nearly
straight forming an angle of about 65° ; anterior margin broadly rounded. Valves

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 589

of subequal depth, the brachial valve being slightly the deeper ; anterior commis-
sure very broadly uniplicate. Surface mostly smooth except for the anterior
margin which is marked by 6 short costae.

Pedicle valve evenly and moderately convex in lateral profile; broadly and
gently inflated ; sides with a moderately deep groove marking off a marginal plica
extending from the beak about four-fifths the distance to the margin.

Brachial valve moderately convex in lateral profile; anterior profile moderately
convex ; umbonal and median regions fairly strongly swollen ; sides precipitous.

Measurements in mm.—Holotype, length 10.2, brachial length 10.0, midwidth
8.2, hinge width 1.5, anterior width 9.5, thickness 5.7.

Type.—Holotype: 117171.

Horizon and locality—Pogonip group (sponge beds=Anomalorthis zone),
in Nevada: In Ikes Canyon, # mile above the mouth, east side of the Toquima
Range, Roberts Mountains (1°) Quadrangle.

Discussion.—This species may be identified by its generally compressed form
and the presence of a few strong costae confined to the anterior margin. The
species is quite unlike J. costata Ulrich and Cooper which is more robust and
which has the costae extending at least to the middle. It also differs from
I. paucicostata which is more broadly triangular and in which the costae are
stronger and occupy the anterior third.

IDIOSTROPHIA PERFECTA Ulrich and Cooper
Plate 109,A, figures 1-8

Idiostrophia perfecta ULRicH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 631, 1936; Geol.
Soc. Amer. Special Pap. 13, p. 249, pl. 56F, figs. 15-17, 19-21, text figs. 12, 13, 1938.

Types.—Holotype: 92885a; paratypes: 92885b-d; figured hypotype: 117173.

Horizon and locality—Mystic Conglomerate, in Quebec, Canada: Range 6,
Lot 20, Stanbridge Township.

Table Head series (middle to upper half) in Newfoundland: 24 to 3 miles
south of Belle Burns.

IDIOSTROPHIA PLICATA Cooper, new species
Plate 109, C, figures 14-17

Shell small for the genus, triangular in outline ; length and width nearly equal ;
sides straight, forming an apical angle of about 70°. Anterior margin broadly
rounded. Anterior commissure broadly uniplicate (?). Surface of posterior half
smooth, anterior half marked by 4 strong, low, rounded costae.

Pedicle valve moderately convex in lateral profile, broadly convex in anterior
profile. Umbonal marginal plica narrow ending anteriorly in a narrowly rounded
projection. Lateral area narrowly grooved and concave. Beak small, incurved
slightly.

Brachial valve somewhat more convex and somewhat deeper than the pedicle
valve in lateral profile ; anterior profile broadly and gently convex. Umbo nar-
rowly swollen; median region gently inflated. Lateral area broadly concave.

590 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—Holotype, length 9.4, brachial length 9.5, midwidth
6.6, anterior width 9.8, thickness 6.2.

Type.—Holotype: 117172.

Horizon and locality —Table Head series in Newfoundland: At Table Point.

Discussion——This species is broadly triangular and is marked along the an-
terior third by a few strong costae. The valves are also subequal in depth and
both are moderately compressed. The species is unlike J. costata in outline and
ornamentation ; it is different from J. paucicostata in having the costae extend
nearly to the middle.

IDIOSTROPHIA sp. 1
Plate 113, A, figures 1-5

Shell small, elongate triangular; posterolateral margins nearly straight, form-
ing an apical angle of 55°; greatest width at the front. Valves moderately con-
vex in lateral profile; brachial valve slightly deeper than the pedicle valve. Sur-
face smooth except at the anterior margin which is costate; 5 costae mark the
pedicle valve and 4 the brachial valve. Median costa on pedicle valve opposing
a median sulcus on brachial valve, both narrow. Brachial valve marked by a faint
depressed line from beak to median depression. Both valves with median septa,
that of the brachial valve being the longer.

Measurements in mm.—66308a, length 5.5, brachial length 5.3, width 4.4,
thickness 2.9.

Figured specimens.—66308a,b.

Horizon and locality. —Boulder in Mystic conglomerate in Quebec, Canada:
In Range 6, Lot 20, Stanbridge Township.

Discussion.—These specimens are the smallest ones of Jdiostrophia known,
but they may represent the young of some species. Immature characters may be
seen in the fact that the odd number of costae is on the pedicle valve while the
space between the median 2 on the pedicle valve forms an indistinct sulcus. No
species is available for comparison.

Genus NEOSTROPHIA Ulrich and Cooper, 1936

Neostrophia Utricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 631, 1936; Geol. Soc.
Amer. Special Pap. 13, p. 252, 1938.

NEOSTROPHIA ? GREGARIA Cooper, new species
Plate 120, A, figures 1-6

Shell small, subpentagonal to subcircular in outline, length and width about
equal. Beak obtuse ; greatest width generally at about the middle; sides rounded.
Surface smooth.

Pedicle valve gently convex and with the greatest convexity in the umbonal
region. Umbo somewhat narrowly swollen; sulcus originating at about the mid-
dle or slightly posterior to it, widening rapidly to occupy more than half the
width, shallow and ending in a short, narrowly rounded tongue. Ridges bound-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 591

ing sulcus prominent and subangular. Flanks concave to slightly convex and
with steep slopes to the margins.

Brachial valve equal in depth to or slightly deeper than the pedicle valve, gently
convex in lateral profile and with the greatest curvature at the umbo; moderately
convex in anterior profile. Fold originating at the middle, somewhat narrowly
rounded, moderately elevated. Flanks strongly rounded and with steep slopes to
the margins.

Interior: Pedicle valve provided with an elongate spondylium supported by a
septum that extends from the beak for fully a third the length. Cruralium of
brachial valve short, supported by a septum extending from the beak nearly to
the middle of the valve.

Measurements in mm.—

Brachial
Length length Width Thickness
PAI OYE ao, «hielo eile nus me 2 28 6.2 5.9 6.5 4.3
Earapgne, CUUEZIOA) 6 oss aie ees ding we 6.5 6.4 7.4 3.3
“ Crr1greeyes Tae 5.6 5.4 6.0 3.1

Types.—Holotype: 111310b; figured paratype: 111310a; unfigured paratypes:
1113 0c-f.

Horizon and locality—Bromide formation (Pooleville member-O-roplecia
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek, about center
sec, 35, (.5 5., R. tE., Criner Hills, Carter County,

Discussion—These interesting little shells have been tentatively placed in the
genus Neostrophia because of their camarelloid interiors and the strong rounded
fold of the brachial valve. They differ from known Neostrophia in their small
size and lack of anterior plication other than the median fold.

NEOSTROPHIA SUBCOSTATA Ulrich and Cooper
Plate 120, B, figures 7-16

Neostrophia costata UtricH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 631, 1936; Geol.
Soc. Amer. Special Pap. 13, p. 252, pl. 56G, figs. 18, 22-31, 35, text fig. 14, 1938.

Types.—Holotype: 66309a ; paratypes: 66309b-f.
Horizon and locality.— Boulder in the Mystic conglomerate in Quebec, Canada:
Range 6, Lot 20, Stanbridge Township, near Mystic.

NEOSTROPHIA ? sp. 1
Plate 120, C, figs. 17, 18

Shell small, pentagonal in outline ; greatest width anterior to the middle; valves
subequally convex ; surface smooth. Pedical valve with a shallow sulcus originat-
ing just posterior to the middle. Brachial valve with a rounded, low fold set off
from the flanks by shallow, narrow grooves. Fold often with small median groove
and sulcus with faint median costa. Both valves with a long median septum.

Measurements in mm.—Brachial valve, length 4.3, width 3.8.

Figured specimens.—117176a,b.

592 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality—Ward Cove ? formation in Virginia: On Jeff Gilles-
pie’s place in Thompson Valley, 14 miles southwest of Tazewell, Pounding Mill
(15’) Quadrangle.

Discussion—The position of this little species is uncertain. The specimens
may represent the young of some Camerella, but they seem more like adults. The
median fold is better developed than is usual in the young of Camerella. The
specimens suggest N. ? gregaria but have a more pronounced fold and a more
elongate outline.

LIRICAMERA Cooper, new genus

(Latin, lira, ridge between 2 furrows; camera, chamber)

Biconvex, subcircular in outline, gently uniplicate; surface completely costel-
late. Pedicle valve with moderately wide interarea. Pedicle interior with long
spondylium supported by a long median septum. Brachial interior with a shallow
cruralium like that of Camereila.

Genotype.—Liricamera nevadensis Cooper, new species.

This genus is clearly an early elaboration of Camerella which still retains some
primitive characters. The interior details are like those of Camerella and need
not be elaborated. The genus differs from Camerella in the completely costellate
exterior, most Camerellas being smooth in the posterior third, half, or quarter,
and strongly costate in the anterior part. It differs also in the possession of a
fairly wide and well-developed interarea on both valves. Furthermore, the gen-
tle degree of folding of the anterior commissure is another distinction from
Camerella.

The ornamentation actually suggests that of some species of [diostrophia in
the median groove on one valve. At present this genus is known only from the
Orthidiella zone of the Pogonip formation which contains many other peculiar
brachiopods. The genus is thus a lateral branch of Camerella retaining primitive
features.

LIRICAMERA NEVADENSIS Cooper, new species
Plate 110, H, figures 50-57; plate 122, A, figures 1-8

Subcircular in outline, with all margins rounded ; beaks inconspicuous ; valves
nearly equal in depth; anterior commissure gently uniplicate; surface costellate,
costellae narrowly rounded, about 45 in number; brachial valve with a narrow
median groove; pedicle valve with a corresponding median costella stronger than
the surrounding ones, bifurcated at the front to receive a faint median costella.

Pedicle valve strongly convex in lateral profile, strongly arched in anterior
profile ; beak erect, incurved moderately ; umbonal and median regions swollen ;
flanks swollen and with steep slopes. Median part of anterior third slightly de-
pressed to form a faint sulcus. Spondylium deep and narrow; septum long. In-
terarea well developed.

Brachial valve slightly less convex than the pedicle valve in lateral profile;
anterior profile strongly convex; entire valve swollen; lateral slopes steep;
median region forming a faint fold. Midline marked by a narrow depression

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 593

wider than the other striae and bearing a faint costella. Cruralium shallow and
wide; fulcral plates well developed; brachiophores short, crescentic in section ;
median septum long, elevated. Interarea moderately well developed.

Measurements in mm.—Holotype, length 11.7, brachial length 10.8, width 11.2,
hinge width 4.9, thickness 8.3.

Types—Holotype: 117174g; figured paratypes: 117174d-f,h, 117175b-d,h;
unfigured paratypes: 117174a-c,1-1, 117175a,e,f.

Horizon and locality.—Pogonip group (Orthidiella zone) from the mottled
zone 700 feet below the Eureka quartzite-in Nevada: At the base of the first
ridge east of Frenchman Flat, Las Vegas (1°) Quadrangle.

Discussion.—No other species like this one is now known.

PERIMECOCOELIA Cooper, new genus

(Greek peri, around; meco, long; koilos, hollow)

Transversely and broadly elliptical in outline; biconvex but with the brachial
valve having the greater depth; strongly uniplicate; paucicostate, the posterior
half smooth and the anterior half or less costate.

Pedical valve with an elongate spondylium, narrowed anteriorly, and supported
by a short median septum.

Brachial valve with long cruralium supported by a short median septum not
continued anteriorly ; brachiophores short and stout ; fulcral plates small, defining
a small socket. Adductor field longitudinally elliptical, partially divided by the
cruralium.

Genotype.—Perimecocoelia semicostata Cooper, new species.

Discussion—This genus externally is very suggestive of Parastrophina be-
cause of its transversely elliptical outline, strongly swollen brachial valve, and
paucicostate ornamentation. The transverse outline separates the genus from
most of the camerellids which are usually longitudinally oval or somewhat
triangular.

Inside the pedicle valve the spondylium is like that of Camerella and its allies
in its elongate form and the narrower anterior. Many specimens of Perimeco-
coelia have the spondylium nearly divided into two chambers by processes grow-
ing inwardly from near the center of the structure. No specimens have been
found in which the processes united, although in a few instances they have almost
done so.

The interior of the brachial valve is most suggestive of that of Parastrophina
with its long cruralium. However, it differs from that genus in not having the
alate plates and in possessing a much shorter median septum. The cruralium of
Perimecocoelia is quite unlike that of Camerella which is short and confined to
the beak and supported by a long median septum.

In all the many specimens of the brachial valve available for study the brachio-
phores are short and stubby. Furthermore, they appear to lie under the fulcral
plate which forms an S-bend from the inner wall of the valve to the posterior

594 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

edge of the brachiophore. This is similar to the structure of the brachial plates
of Camerella. Perimecocoelia is thus a camerellid with elongate cruralium.

The adductor field of Perimecocoelia, at least in the present species, is some-
what thickened and is often surrounded by an elevated callus. The posterior scars
are located beside the anterior end of the cruralium; the anterior scars, which
are the larger, are located just anterior to the end of the cruralium and are sepa-
rated by a low ridge extending anterior to the cruralium.

PERIMECOCOELIA ELLIPTICA Cooper, new species
Plate 111, C, figures 27-35

Shell small, broadly triangular in outline, with low, inconspicuous beaks.
Brachial valve slightly deeper than the pedicle valve. Both profiles narrowly
lenticular. Paucicostate, the posterior half smooth and the anterior half strongly
costate ; 2 costae in the sulcus, 3 on the fold, and 2 on the flanks ; fold low, defined
by the 3 strongest costae slightly elevated at the anterior third. Sulcus shallow
and wide, originating in the anterior third.

Measurements in mm.—Holotype, length 7.0, brachial length 7.0, width 8.5,
hinge width 1.7, thickness 4.7.

Type.—Holotype: 111164.

Horizon and locality—Arline formation in Tennessee: North side of old
wagon road in cedar glade, + mile southeast of Friendsville, Concord (T.V.A.
138-SW ) Quadrangle.

Discussion.—This species is similar to P. semicostata but is smaller, with only
2 costae in the sulcus and becoming costate at a less distance from the beak. The
interior of the species is not known, but the elliptical outline, wide sulcus, and
semicostate form all suggest reference to Perimecocoeha rather than Camerella.

PERIMECOCOELIA SEMICOSTATA Cooper, new species
Plate 108, E, figures 21-25; plate 114, C, figures 35-38; plate 117, E, figures 28-51;
plate 117, F, figures 52-59; plate 119, B, figures 6, 7

Parastrophia rotundiformis Wittarp (part), Mus. Comp. Zool., Harvard Coll., vol. 68,
No. 6, p. 290, 1928.

Shell transversely but broadly elliptical in outline; posterior margin broadly
rounded ; lateral margins strongly rounded ; anterior margin somewhat truncated.
Anterior commissure strongly uniplicate; posterior half smooth; anterior half
costate with 3 (rarely 4) costae on the brachial fold and 1 to 3 obscure ones on
the flanks; 2 costae (rarely 3) in the sulcus, and 2 to 4 poorly defined ones on
the flanks.

Pedicle valve unevenly convex in lateral profile, with the most convexity in
the posterior region and with a strongly geniculated tongue; anterior profile
slightly convex ; umbonal region gently swollen; sulcus originating slightly pos-
terior to the middle, deepening and widening abruptly; sulcus bounded by 2
subangular costae that die out with the sulcus posteriorly; flanks nearly flat,

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 595

with moderately steep slopes. Spondylium long and slender, constricted more or
less strongly near the middle. Tongue long, truncated but strongly serrate.

Brachial valve with much greater depth than the pedicle valve and with un-
even lateral profile, the umbonal region swollen but the median and anterior
regions only moderately convex ; anterior profile strongly bowed. Umbonal re-
gion swollen and protruding somewhat posterior to the posterior margin. Me-
dian region swollen. Fold low, rounded in anterior profile, originating near the
middle; flanks swollen, with precipitous slopes. Interior with long and deep
cruralium, thickened adductor field, and no median septum.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (brachial valve)............ ? 9.6 12.4 ? ?
Paratype (pedicle valve 117150f)..... 11.2 ? 14.2 3:2 ?
¢ VERS A Ae 11.0 10.5 12.8 3.9 7.4
- crs fyrraregs6bys. J 33 0.5 9.0 10.7 32 4.7
ia (On Des rH BEEGS SG) 8% sts 9.4 9.4 10.4 3.2 5.5

Types.—Holotype: 117159b; figured paratypes: 117159a,c,d,f, 117161,
111328e, 111333b, 111334b, 111336b, 111338, 111347a, 118013b-f; unfigured
paratypes: 111333a,c,d, 111334a,c,d, 111336a,c, I17159e, 118013a.

Horizon and locality —Effna formation in Virginia: At McNutt Quarry, 12
miles southwest of Bland, Burkes Garden (15’) Quadrangle; Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle; Tilson Mill,
16 miles northeast of Marion, Nebo (T.V.A. 223-NW) Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: 4 miles southwest of
Bland, Bland County; 1.8 miles S. 4° W. of Bethel Church, 5.9 miles due east
of Harrisonburg, Harrisonburg (15’) Quadrangle.

Chatham Hill formation in Virginia: 1.2 miles S. 31° E. of Sharon Springs,
Burkes Garden (15’) Quadrangle.

Botetourt formation in Virginia: I mile northwest of Lexington, Lexington
(15’) Quadrangle.

Edinburg formation (Cyrtonotella zone) in Virginia: In the ravine at the
switch about § mile east of Strasburg Junction, Strasburg (15’) Quadrangle.

Lower 3 feet of the Pratt Ferry formation in Alabama: 0.2 mile southeast of
Pratt Ferry, Blocton (15’) Quadrangle.

Lower Benbolt formation in Virginia: On the south side of Mount Hagan
School, Hilton (T.V.A. 197-NW) Quadrangle.

Discussion.—The species is suggestive of Parastrophina hemiplicata of the
New York Trenton but is less costate and less tumid than is usual in that species.
It is distinguished from P. triangulata by its larger size and elliptical outline.

Willard proposed the name Parastrophia rotundiformis for P. rotunda Win-
chell and Schuchert from the Prosser of Minnesota and Iowa which was preoccu-
pied by Atrypa rotunda Sowerby when that species was assigned to the genus
Parastrophia. Willard referred his Virginia specimens to the Prosser species,
but a number of important differences exist. The Virginia specimens belong to

596 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the genus Perimeococoelia rather than Parastrophina and are referred to P. semi-
costata. The Minnesota species Parastrophina rotundiformis is a much larger
one with more convex valves than the Virginia species. Furthermore, the Prosser
form is more strongly costate and the costae extend at least to the middle of the
valves.

PERIMECOCOELIA TRIANGULATA Cooper, new species
Plate 117, B, figures 3-12

Shell small for the genus, triangular in outline; greatest width anterior to the
middle ; anterolateral extremities narrowly rounded; sides slightly convex. Pos-
terior two-thirds smooth, anterior third costate, 2 costae marking the sulcus,
3 the fold, and 1 strong costa and an obscure one marking the flanks.

Pedicle valve gently convex in the posterior half, nearly flat anteriorly ; um-
bonal region gently swollen; sulcus originating anterior to the middle, moder-
ately deep and forming a short, truncated tongue anteriorly; flanks narrow,
slightly deflected in the direction of the pedicle valve toward the front.

Brachial valve 2 to 3 times as deep as the pedicle valve, moderately convex
in lateral profile with strongly arched and swollen umbo that protrudes anterior
to the pedicle beak. Fold originating near the middle, narrow, low; flanks de-
pressed, strongly rounded and with steep slopes to the margins.

Measurements in mm.—Holotype, length 7.8, brachial length 7.9, width 8.2,
thickness 6.4.

Types.—Holotype: 111342a; unfigured paratypes: 111342b-f.

Horizon and locality—Effna formation in Virginia: Porterfield Quarry, 5
miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This species differs markedly from P. semicostata in outline and
proportions although the costation is similar.

PLECTOCAMARA Cooper, new genus

(Greek plektos, fold; camara, chamber)

Shells small to moderately large, rhynchonelloid in outline and profile. Pedicle
valve shallower than the brachial valve and with a deep sulcus and long tongue.
Beak suberect ; delthyrium as in all camerellids. Brachial valve with prominent
median fold. Valves completely costate ; entire surface covered by closely crowded
wavy, elevated, concentric lines. Pedicle interior with deep, narrow spondylium
supported by a short median septum. Brachial interior with short brachiophores
attached to the floor of the valve to form a narrow notothyrial cavity. Median
septum absent or only a short ridge in front of the notothyrial cavity.

Genotype.—Plectocamara costata Cooper, new species.

Discussion—At first glance the species of this genus suggest small rhyncho-
nellids such as Camarotoechia or Rhynchotrema, but study of the delthyrial re-
gion, which has no deltidial plates and is like Camerella, will, along with the
interiors, help to distinguish these peculiar little shells. Inside the pedicle valve
the spondylium is long, narrow, and deep and is sessile at the posterior as is

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 597

common with camerelloid shells. The median septum is best defined at the front
of the spondylium but is not extended for a great distance anterior to the
anterior end of that structure.

The most important features are in the interior of the brachial valve. The
brachiophores and their supports are like those of Camereila, but instead of meet-
ing the median septum in the direction of the brachial valve they are attached
to the floor to form a narrow notothyrial cavity rather than a short cruralium as
in Camerella. In Plectocamara the median septum is reduced to a mere ridge
extending anteriorly of the notothyrial cavity for a short distance and dividing
the small adductor impressions.

PLECTOCAMARA ASEPTATA Cooper, new species

Plate 122, C, figures 22-26; plate 122, D, figures 27-29; plate 123, B, figures 7-11; plate 123, C,
figures 12-16; plate 123, G, figures 32-54; plate 126, E, figures 25-29

Small subtriangular to subelliptical in outline, wider than long, widest slightly
anterior to the middle. Beak obtuse, sides straight ; anterolateral extremities nar-
rowly rounded. Anterior margin straight. Surface costate, costae subangular,
with the flanks marked by 7 or 8 and the fold by 3 or 4, with 2 or 3 costae in the
sulcus.

Pedicle valve gently convex in lateral profile and broadly convex in anterior
profile. Beak short, suberect. Umbo gently convex. Sulcus originating 14 to 2
mm. anterior to the beak, strongly depressed anteriorly to form a fairly sharply
geniculated tongue. Flanks bounding sulcus flattened to slightly convex and with
gentle slopes to the margin in the anterior region and steepening posteriorly.

Brachial valve moderately convex in lateral and anterior profiles ; fold originat-
ing about I mm. anterior to the beak, moderately strongly elevated anteriorly.
Flanks depressed below fold, gently rounded and with gentle slopes to the
margins.

Measurements in mm.—

Brachial
Length length Width Thickness
GIP Vee cos aves 1S cot chick tees = 6.1 5.4 7.2 4.1
Pasatype.(z1rg6rb)i. 0. 2.0... e208 5.6 5.2 6.5 3.4
. CF EPIHIC). sasdees 1. oe 5.2 4.8 6.1 3.9

Types—Holotype: 111361a; figured paratypes: 111361b,c, 117180b, 117181,
117182a-d ; unfigured paratypes: 111370a, 117182e; figured specimen: 117180a.

Horizon and locality—Lower Benbolt formation in Virginia: 14 miles west
of Rye Cove at the Brick Church, Clinchport (T.V.A. 188-NW) Quadrangle ;
0.2 mile south of the middle fork of Moccasin Creek, 15 miles south of Hanson-
ville, Hansonville (T.V.A. 205-SW) Quadrangle; south side of Mount Hagan
Church, Hilton (T.V.A. 197-NW) Quadrangle.

Benbolt formation in Tennessee: At Evans Ferry, U. S. Highway 25E, north
of Indian Creek, Howard Quarter (T.V.A. 162-NW) Quadrangle.

From limestone with Oligorhynchia in Virginia: 4 mile southeast of Richpatch,
Eagle Rock (15’) Quadrangle.

598 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Ward Cove formation in Tennessee: 2 miles southwest of Hall Crossroad,
Fountain City (T.V.A. 146-SW) Quadrangle.

Sevier formation in Tennessee: + mile northeast of Miser, Louisville (T.V.A.
138-SE) Quadrangle.

Discussion.—This species can be recognized by its fairly large size, obtuse and
elevated beak, narrowly rounded anterolateral extremities and numerously cos-
tated flanks. It differs from P. costata in the latter character as well as in size
and form.

PLECTOCAMARA COSTATA Cooper, new species
Plate 122, B, figures 9-21; plate 123, E, figures 22-26; plate 123, F, figures 27-31;
plate 138, F, figures 40-42

Shell small, subpentagonal in outline; posterolateral margins straight forming
an angle of about 120°. Sides narrowly rounded; anterior margin subtruncated ;
anterior commissure strongly uniplicate ; surface costate, fold marked by 3 costae,
sulcus containing 2 costae, and flanks marked by 4 costae.

Pedicle valve slightly convex in lateral profile; broadly convex in anterior
profile but depressed medianly ; umbo smooth; sulcus originating about 1 mm.
anterior to the beak, deepening rapidly and forming a moderately long, narrow
tongue. Flanks depressed convex, with gentle slopes. .

Brachial valve deeper than the pedicle one and moderately convex in lateral
profile; strongly convex in anterior profile. Fold originating on the umbo,
strongly elevated at the front and with steep sides. Flanks rounded and with
steep slopes depressed below the fold. Interior with sessile cruralium.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FIGIOEY PE 44 ¢ystee ssldbn > 5.5 5.2 6.6 1.5 3.9
Paratype (111368a) .... 4.6 4.2 4.9 1.0 1.9

Types——Holotype: 111360a; figured paratypes: 111356, 111368a,b, 117184,
117943a,b; figured specimen: 123457; unfigured paratype: 117184b.

Horizon and locality.—Lincolnshire formation (Hogskin member) in Tennes-
see: 3 and 44 miles west-southwest of Thorn Hill; 0.4 mile east-northeast of Red
Hill; $ mile north of Thorn Hill on U. S. Highway 25E; Avondale (T.V.A.
162-SW ) Quadrangle; 1 mile southwest of Washburn, Dutch Valley, (T.V.A.
154-SE) Quadrangle; 4 mile north of Eidson, Kyles Ford (T.V.A. 170-SE)
Quadrangle ; 4 mile north of Rose Hill, Maynardville (T.V.A. 145-SE) Quad-
rangle; 4 mile southwest of Fleanor Mill, Powell Station (T.V.A. 137-SE)
Quadrangle; Evans Ferry section, north of Indian Creek, Howard Quarter
(T.V.A. 162-NW) Quadrangle; 2 miles southwest and 1.7 miles northwest of
Hall Crossroad, Fountain City (T.V.A. 146-SW) Quadrangle.

Lincolnshire formation in Virginia: Quarry at Marcem, 2 miles west of Gate
City, Gate City (T.V.A. 188-SE) Quadrangle.

Ward Cove formation in Tennessee: ? mile southeast of Mount Eager Church,
Powder Springs (T.V.A. 154-SW) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 599

Discussion—tThis species differs from P. aseptata in having less numerous
and less closely spaced costae, in having a less narrow umbo and less erect beak,
in having little tendency for development of extra costae on the fold and the sul-
cus, less costae on the flanks, and in having the fold originate nearer the middle.
The two species are actually fairly similar, but no instances of 3 costae in the
sulcus and 4 on the fold have been observed in P. costata.

Like P. aseptata this species is also a very variable one, but the variations are
not as extreme as in the Benbolt species. Generally, P. costata does not at-
tain as large a size as P. aseptata, and the sulcus is not usually so deep. Further-
more, the species is more conservative in its costation, the costae of the flanks
remaining fairly constant.

PLECTOCAMARA ERECTA Cooper, new species

Plate 123, D, figures 17-21

Shell of usual size for the genus, length and width about equal; outline sub-
pentagonal ; posterolateral margins straight, lateral margins narrowly rounded;
anterior margin truncated. Strongly uniplicate. Surface costate, with 3 costae
on the fold, 2 in the sulcus, and 4 on the flanks.

Lateral profile slightly convex but with a local inflation at the umbo; anterior
profile faintly convex. Sulcus originating 2 to 24 mm. anterior to the beak, deep-
ening anteriorly and terminating in a narrow, short tongue. Sides of sulcus pre-
cipitous at the front. Costae bounding sulcus elevated and protuberant an-
teriorly ; flanks flat and inclined fairly steeply.

Brachial valve moderately convex in lateral profile, broadly and moderately
convex in anterior profile; brachial valve slightly deeper than the pedicle valve ;
umbonal region moderately inflated ; fold originating on the umbo but not ele-
vated strongly throughout its length. Fold rounded in lateral profile; flanks
moderately swollen and with steep slopes, not strongly depressed below the level
of the fold.

Measurements in mm.—Holotype, length 5.5, brachial length 5.1, width 5.9,
hinge width 1.4, thickness 3.7.

Type.—Holotype: 117183.

Horizon and locality—Wardell formation in Tennessee: Northeast side of
Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

Discussion.—This species is characterized by its erect form, the width and
length being nearly equal, and by the sparse costation. It differs from P. aseptata
in having less width, less costae, and a narrower fold and sulcus. Plectocamara
erecta is also similar to P. costata in its costation, but it is not so wide, has a
more swollen brachial valve, less elevated fold, and a narrower sulcus.

Plectocamara is a rare genus in the Wardell formation. Consequently, the
foregoing species is based on a single good specimen and one other exfoliated one
which shows some details of the interior.

600 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PLECTOCAMARA MAGNA Cooper, new species
Plate 122, G, figures 38-51

Large for the genus, wider than long, with a transversely but broadly ellipti-
cal outline; nearly as thick as long. Sides oblique, straight, forming an apical
angle of 125°. Sides narrowly rounded; anterior margin truncated. Strongly
uniplicate. Surface costate, 3 costae on the fold, 2 in the sulcus, and 7 on the
flanks.

Pedicle valve fairly strongly convex in lateral profile with the maximum con-
vexity at about the middle. Anterior profile broadly and gently convex; sulcus
originating about I mm. anterior to the beak, narrow, deepening and widening
moderately anteriorly where it occupies about one-third the width at the front
margin. Tongue long and narrow. Sulcus with precipitous sides defined by
strong marginal subangular costae. Flanks moderately convex and with mod-
erate slopes depressed below the costae forming the sulcus margin. Spondylium
moderately large and deep.

Brachial valve having about the same convexity and depth as the pedicle valve
in lateral profile ; anterior profile with gently convex top but steeply sloping sides.
Umbonal region moderately swollen. Fold originating on the umbo, narrow
and strongly elevated anteriorly, with precipitous sides at the front. Flanks
moderately swollen and depressed well below the fold. Brachial plates stout ;
muscle marks deep and prominent.

Measurements in mm.—Holotype, length 8.0, brachial length 7.3, width 9.5,
hinge width 2.8, thickness 7.3.

Types.—Holotype: 117185a; figured paratype: 117185b; unfigured paratype:
I17185c.

Horizon and locality.—Base of Shippensburg formation (Pinesburg member-
Echinosphaerites zone) in Maryland: On U. S. Highway 40, near Wilson on
the west side of Conococheague Creek, 7 miles west of Hagerstown, Williamsport
(15’) Quadrangle.

Edinburg limestone (Cyrtonotella zone) in Virginia: Ravine at the switch
4 mile east of Strasburg Junction; 0.2 mile east of Strasburg Junction, Stras-
burg (15’) Quadrangle.

Discussion.—This species is characterized by its large size and tumid valves.
Except for P. transversa it is the largest species known. It differs from P. asep-
tata, which it most resembles, in having a narrower fold and sulcus, more costae
on the flanks, and a less erect beak. Plectocamara transversa has a wider hinge,
wider sulcus, and more costae on the flanks than P. magna.

PLECTOCAMARA ROTUNDA Cooper, new species
Plate 122, FE, figures 30-34; plate 268, C, figures 7-11

Large for the genus, slightly wider than long ; transversely and broadly ellipti-
cal to subcircular in outline. Sides broadly rounded; anterior margin truncated.
Strongly uniplicate. Surface costate, 3 costae (rarely 4) on the fold, 2 (rarely 3)
in the sulcus, and 5 to 7 on the flanks.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 601

Pedicle valve gently convex in lateral profile; broadly and gently convex in
anterior profile. Umbonal region gently convex; sulcus originating 2 mm. an-
terior to the beak, deepening rapidly and occupying about half the width at the
front. Tongue long, bent at an angle slightly greater than a right angle. Sides
of sulcus opposite place of geniculation of tongue precipitous and bounded by
an extravagantly developed costa on each side. Flanks gently convex but with
steep slopes.

Brachial valve somewhat deeper than the pedicle valve, slightly more convex
in lateral profile; anterior profile narrowly convex and with steep lateral slopes.
Umbonal and median region flattened. Fold originating at or near the middle,
strongly elevated anteriorly and with precipitous sides. Flanks strongly rounded
and with steep slopes.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness

Ripiotype). iv. 2 vee eects... bas eei< 5.7 5.5 6.6 1.9 4.4
Pacatype \CEIZTSOD) oie .n 5 wie.s sinys os 6.2 5.7 6.7 27 5.8
as ee eats 7) Ee er 6.2 5.7 6.5 2.1 5.3
‘a (ar7rGed ys 222808) NS 6.0 5.4 7.1 2.2 4.8

Types.—Holotype: 117186a ; figured paratype: 117186e; unfigured paratypes:
117186b-d.

Horizon and locality——Chatham Hill formation in Virginia: 1.2 miles S, 31°
KE. of Sharon Springs, Burkes Garden (15’) Quadrangle.

Discussion—This species is characterized by its rotund form and considera-
ble thickness. It is suggestive of the Benbolt P. aseptata but differs in its greater
thickness, flattened umbo of the brachial valve, and more extravagantly developed
fold and sulcus. These features will also differentiate it from P. costata.

PLECTOCAMARA SULCATA Cooper, new species
Plate 123, A, figures 1-6

Shell small, wider than long, sides narrowly rounded; strongly uniplicate;
costate, with 2 costae in the sulcus, 3 on the fold, and 4 on the flanks.

Pedicle valve nearly flat in lateral profile with the surface sloping anteriorly ;
anterior profile gently convex; sulcus originating about I mm. anterior to the
beak, deepening abruptly, but narrow throughout. Sides of sulcus precipitous;
costae bounding sulcus produced anteriorly and greatly elevated in a direction
toward the pedicle valve; flanks flattened but with steep slopes.

Brachial valve gently convex in lateral profile; moderately convex in anterior
profile. Fold originating slightly anterior to the middle, abruptly but not strongly
elevated. Fold narrow and with closely crowded costae. Flanks moderately swol-
len, depressed anteriorly to emphasize the lateral margins of the fold.

Measurements in mm.—Holotype, length 4.2, brachial length 3.8, width 5.1,
hinge width ?, thickness 3.3.

Type.—Holotype: 117187.

Horizon and locality.—Benbolt formation in Virginia: On the south side of

602 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Mount Hagan School, southeast corner of the northeast subquad., Hilton (T.V.A.
197-NW) Quadrangle.

Discussion—This species is most similar to small, strongly costate specimens
of P. aseptata but differs in the greater depth of the sulcus and in the extravagant
development of the anterior ends of the costae bounding the sulcus.

PLECTOCAMARA TRANSVERSA Cooper, new species
Plate 122, F, figures 35-37

Shell large for the genus, wide, with gently oblique posterolateral margins
forming a broadly obtuse apical angle. Sulcus originating at the beak, deep and
moderately wide, occupied by 2 costae. Flanks flattened to gently concave, de-
pressed below the strong bounding costae of the sulcus, marked by 9 costae. Lat-
eral profile gently convex. Spondylium short, deep, sessile at the posterior but
elevated on a short median septum at the anterior.

Measurements in mm.—Holotype, length 8.7, width 12.4.

Type.—Holotype: 117188.

Horizon and locality —Edinburg formation (lower part of Nidulites zone) in
Virginia. On U. S. Highway 11, 100 yards south of Battlefield Crystal Caverns
entrance, I mile north of Strasburg, Strasburg (15’) Quadrangle.

Discussion.—This is the largest of the known species of this genus. Besides
its size it is characterized by its great width and numerous costae.

Subfamily STENOCAMARINAE Cooper, new subfamily

Camerellidae having long, discrete, subparallel dental plates in the pedicle valve.

STENOCAMARA Cooper, new genus

(Greek steno, narrow; camara, chamber)

Shell suggesting Camerella in outline and profile but not plicated except for
fold and sulcus. Anterior commissure strongly uniplicate; hinge narrow; sur-
face marked by concentric lines of growth only.

Pedicle valve more or less strongly sulcate; beak small, somewhat incurved ;
interarea small and narrow; interior with 2 long, subparallel dental piates defin-
ing a long, deep, and very narrow delthyrial chamber.

Brachial valve with incurved beak and strong median fold; interior charac-
terized by a short V-shaped cruralium supported by a long and elevated median
septum.

Genotype.—Stenocamara perplexa Cooper, new species.

Discussion—This genus is characterized by having subparallel dental plates
in the pedicle valve and a cruralium in the brachial valve. Externally the genus
suggests the syntrophids because of its smooth exterior and strongly uniplicate
anterior commissure. The structure of the brachial valve is most like Xenelasma
Ulrich and Cooper which occurs in the Nittany formation and its equivalents in
Virginia, Tennessee, and Texas. Xenelasma is characterized by having dental

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 603

plates in the pedicle valve and a cruralium in the brachial valve. Exteriorly this
genus is smooth but has rotund moderately uniplicate shells. Stenocamara differs
from Xenelasma in having exceptionally long dental plates and an exceedingly
narrow delthyrial chamber, whereas these features in the Canadian genus are
shorter and wide. In the brachial valve the two also differ. Xenelasma is
characterized by an elongate and almost sessile cruralium; the same structure
in Stenocamara is short and like that of Camerella. This genus thus combines
features of the camerellids and of the syntrophids.

STENOCAMARA BICOSTATA Cooper, new species
Plate 115, G, figures 43-48

Shell small, slightly wider than long; greatest width slightly anterior to the
middle ; beak slightly greater than a right angle, posterolateral margins straight ;
lateral margins narrowly rounded; front truncated. Surface smooth in the pos-
terior half and on the flanks. Sulcus with 2 costae and the fold with 3.

Pedicle valve slightly convex with the greatest convexity at the umbo; sulcus
originating at about the middle, wide and shallow, occupying more than half the
shell width; tongue short. Midregion slightly swollen. Flanks slightly concave
and with very gentle slopes to the margins. Interior with long, slightly diverging
dental plates.

Brachial valve gently convex in the anterior part but strongly convex in the
umbonal region; strongly convex in anterior profile; swollen in the midregion.
Fold originating anterior to the middle, low, and bearing in its median region a
longitudinal depression occupied by a costa depressed below those bounding the
fold. Costae forming margins of fold angular and strong; flanks narrowly
rounded and with steep slopes.

Measurements in mm.—Holotype, length 5.8, brachial length 5.4, width 6.2,
hinge width 1.9, thickness 4.1.

Type.—Holotype: 111317.

Horizon and locality—Mosheim formation in Alabama: 4 mile east of Oden-
ville, Springville (30’) Quadrangle.

Discussion.—This species differs from S. perplexa in its small size and the
presence of strong costae at the anterior.

STENOCAMARA PERPLEXA Cooper, new species
Plate 111, E, figures 41-45; plate 119, C, figure 8; plate 268, H, figures 33-40

Shell of moderate to large size for the genus, length and width about equal;
widest anterior to the middle. Hinge narrow; outline triangular to ovate; sides
gently curved ; anterolateral extremities narrowly rounded ; anterior margin trun-
cated, sides and pedicle beak forming an angle of about 93°. Valves unequally
convex, the brachial valve having the greater depth. Surface smooth.

Pedicle valve gently convex in lateral and anterior profiles; umbo and antero-
umbonal region gently swollen; sulcus broad and shallow, originating at about
the valve middle; tongue short and squarish. Surface of sulcus convex; sulcus

604 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

bounded by short, narrow, and oblique costae. Flanks gently convex and sloping
steeply to the sides. Dental plates long, extending for about one-quarter the
length.

Brachial valve moderately convex in lateral profile, strongly and somewhat
narrowly convex in anterior profile ; beak narrow and long, curved over the inter-
area of the pedicle valve. Umbo narrow and swollen; posteromedian region
swollen; fold originating just posterior to the middle, narrow, steep sides and
with flattened surface; midline of fold marked by a slight depression; fold
bounded by narrow and fairly deep sulci; flanks narrowly rounded and with
steep slopes.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holatypers. faesastcamdaaes oo 14.4 13.7 14.7 4.5 11.3
Paratmpe (123280). i: aimesen 11.8 11.5 11.0 3.8 6.8

Types.—Holotype: 111321; figured paratypes: 111322a, 123289; unfigured
paratypes: 111318a-h, 111322b,c.

Horizon and locality.—Ellett formation (55 feet above the base) in Virginia:
On Indian Run, 3 mile northwest of Lusters Gate, Blacksburg (15’) Quadrangle.

Mosheim limestone in Tennessee: 4 mile east of the railroad station just east of
Morristown, Morristown (T.V.A. 163-NE) Quadrangle; along the Southern
RR. 3 mile south of Mosheim, Mosheim (T.V.A. 181-NW) Quadrangle; Climer
Post Office, 7 miles east of Cleveland, Benton (T.V.A. 126-NW) Quadrangle.

Same limestone in Alabama: 4 mile southwest of Newhope Church, Vandiver
(15’) Quadrangle; $ mile east of Odenville, Springville (30’) Quadrangle.

Discussion—This species is characterized by its oval or pentameral outline,
the elevated and abrupt median fold, and moderately deep sulcus. It is larger
than S. bicostata and completely unlike that species.

Family PARASTROPHINIDAE Ulrich and Cooper, 1936

Syntrophoidea having a spondylium duplex and a cruralium duplex of sub-
parallel brachiophore plates with alate processes.

Subfamily PARASTROPHININAE Schuchert, 1929

Parastrophinidae having a cruralium duplex.

Genus PARASTROPHINA Schuchert and LeVene, 1929

Parastrophia HAut and CLARKE, Pal. New York, vol. 8, pt. 2, p. 221, 1893.
Parastrophina ScHUCHERT and LEVENE, Amer. Journ. Sci., vol. 17, p. 121, 1929.—StT. JosEPH,
Geol. Mag., vol. 78, No. 5, p. 371, 1941.

PARASTROPHINA BERNENSIS (Sardeson)

Camarella bernensis Sarpeson, Minnesota Acad. Nat. Sci., Bull. 3, p. 328, pl. 4, figs. 4-6,
1892.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 605

Anastrophia ? hemiplicata WINCHELL and ScuucHERT, Geol. Minnesota, vol. 3, p. 382, pl. 30,
figs. 29-31, 1893.

This name is revived for specimens from the Prosser limestone commonly re-
ferred to P. hemiplicata Hall. All the specimens from Minnesota, Wisconsin,
and Iowa in the National Collections referred to Hall’s name are clearly a differ-
ent species from the New York one. Winchell and Schuchert mention that their
specimens differ from New York examples “in having the umbo of the dorsal
valve more tumid and elevated beyond that of the ventral valve. The transverse
diameter in the former [Minnesota specimens] is also shorter, while the indi-
viduals are commonly smaller than those from eastern localities.”

A fine specimen in the National Collections (24209) labeled Camarella bernen-
sis by C. W. Hall indicates a more circular species than P. hemiplicata in its
present average form. Hall’s label further states that ‘The type is from Berne,
Minn.—It is unfortunately an immature specimen a little distorted.”

It is evident from the few specimens in the National Museum that P. bernensts,
like other species of the genus, is also a very variable species. These species to be
satisfactorily delimited will have to be restudied on the basis of large collections.

PARASTROPHINA BILOBATA Cooper, new species
Plate 118, D, figures 30-44; plate 119, A, figures 1-5

Shell small, subcircular outline; valves nearly equal in depth; sides rounded ;
anterior margin indented medianly ; anterior commissure broadly uniplicate ; lat-
eral commissure straight ; surface paucicostate, with 3 or 4 costae in the sulcus,
3 or 4 on the fold, and about 3 on the flanks.

Pedicle valve unevenly convex in lateral profile, the posterior quarter moder-
ately convex in the umbonal region, the median half nearly flat and the anterior
half moderately convex; anterior profile broadly and gently convex and with
moderately steeply sloping lateral slopes. Umbonal region and area just anterior
to it strongly swollen; sulcus originating at the middle, shallow and narrow but
deepening suddenly near the anterior margin. Sulcus with a median trough
forming the deepest part and flanked by costae which are depressed below the
strong, narrowly rounded costae bounding the sulcus. Tongue short, truncated.
Interior with wide and deep spondylium supported by a short, stout median
septum.

Brachial valve fairly evenly and moderately convex in lateral profile ; anterior
profile broadly convex with the top somewhat flattened and steeply descending
sides; fold originating at about the middle, low and indistinct throughout its
length ; median part of fold depressed into a narrow and moderately deep sulcus
containing a single costa; anterior of fold deeply indented by above-mentioned
median sulcus and forming the deep emargination characteristic of the species.
Flanks inflated and with steep slopes. Interior with narrow and deep notothyrial
cavity ; cruralium elongate, septum short; brachiophores short; alate plates well
developed ; supporting plates often thickened particularly at or near junction with
alate plates. Adductor field elongate; posterior pair of adductor scars small, an-

606 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

terior pair elongate; median septum continued forward as a low median ridge
anterior to the anterior end of the adductor field.

Measurements in mm.—Holotype, length 4.4, brachial length 4.2, width 5.0,
hinge width 1.6, thickness 3.0.

Types.—Holotype: 117166b; figured paratypes: 117166a,c-f,h-j; unfigured
paratype: 117166g.

Horizon and locality.—Lower 3 feet of the Pratt Ferry formation in Alabama:
0.2 mile southeast of Pratt Perry, Blocton (15’) Quadrangle.

Discussion.—This species is quite unlike any other member of the genus yet
described. It is the smallest species of the genus known, the largest specimen
having a width slightly greater than 6 mm. It is particularly characterized by
the anterior emargination produced by the sulcus within the median fold of the
brachial valve.

PARASTROPHINA HEMIPLICATA (Hall)
Plate 106, G, figures 33-44; plate 117, D, figures 19-27

Synonymy: For full synonymy of this species up to 1915, see R. S. Bassler, Bibliographic
index of American Ordovician and Silurian fossils, U. S. Nat. Mus. Bull. 92, p. 945. When
using this synonymy several citations should be excluded. One such is Anastrophia ? hemi-
plicata Winchell and Schuchert. The citation under Parastrophia hemiplicata Schuchert,
Proc. U. S. Nat. Mus., vol. 22, 1900, p. 158, refers to Baffin Land specimens that were
described by S. K. Roy in 1941 as P. hemiplicata minor. Roy also determined the age of the
beds in which these specimens occurred as late Ordovician. The references to Camerella
bernensis should also be excluded. This seems to be a valid species (see above).

The following references from 1915 to the present writing should be added:

Camerelia hemiplicata (Hall) ScHucHERT and Cooper, Mem. Peabody Mus. Nat. Hist.,

vol. 4, pt. I, p. 168, pl. 25, figs. 3, 4, 6, 9-11, 16, 24, 43, 1932.
Parastrophina hemiplicata (Hall) Kay, Bull. Geol. Soc. Amer., vol. 48, p. 330, pl. 9, (Hull),
1937.—ST. JosEPH, Geol. Mag., vol. 78, No. 5, p. 377, text figs. 3-5, 1041.

Moderately large, transversely subelliptical in outline ; valves of unequal depth,
the brachial valve having the greater depth; posterolateral margins straight ;
sides narrowly rounded ; anterior margin truncated ; anterior commissure unipli-
cate; surface paucicostate, the fold having 3 to 5 costae, the sulcus 2 to 4, and
the flanks 2 or 3.

Pedicle valve gently convex in lateral profile ; anterior profile very broadly and
gently convex; umbonal and median regions swollen; sulcus originating at the
middle, wide, shallow, forming a short serrate tongue. Flanks somewhat swollen.

Brachial valve moderately convex in lateral profile with the greatest convexity
in the umbonal region. Anterior profile strongly bowed, with steep lateral slopes.
Umbo and median region swollen; fold originating at the middle, low in some
specimens with the median costae depressed slightly below those forming the
outer margins of the fold; flanks swollen and with steep slopes.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (117168b).......... 10.4 10.5 12.9 aie 8.0

‘1 CTIF TOSS) HA Lis YG 10.9 10.8 12.9 24°? 8.5

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 607

Figured hypotypes.—117168a-c ; 111324.

Horizon and locality—Lower Martinsburg formation (part with Brongniar-
tella= Salona) in Virginia: On Virginia County Highway 617=910, 0.15 miles
north of Green Mount Church, Broadway (15’) Quadrangle.

Discussion.—The foregoing description is based on five specimens from the
base of the Martinsburg (Salona) shale at Green Mount Church north of Har-
risonburg, Va. This is a rare shell in Virginia, and the characters of the speci-
mens at hand are not in complete conformity with those of the specimens referred
to this species from New York and elsewhere.

The National Museum collection of Parastrophina hemiplicata is small and
unsatisfactory, but even so, it shows clearly that considerable revision is needed
in this genus. The specimens from Watertown, N. Y., a locality mentioned in
Hall’s original description of the species, are fairly small shells having a length
of 11 or 12 mm. and a width of 12 to 15 mm. The Virginia shells are somewhat
smaller and somewhat rounder than those from Watertown. The latter speci-
mens are quite different from large ones from Salona, Pa., and Larrabee
Point, Vt., which have a width of 19 mm. Other specimens from Montreal,
Quebec, are not unlike the Watertown shells but have different ribbing charac-
ters. The National Collection specimens, unfortunately, do not have detailed
stratigraphic information, but the variety of forms indicates beyond doubt that
they represent numerous levels and that geographic variation also plays a role
of importance. The species is in need of revision, but this cannot be done with-
out very extensive collections. The identification of the Virginia specimens is
thus a tentative one.

PARASTROPHINA ROTUNDIFORMIS (Willard)
Plate 117, A, figures 1, 2

Anastrophia (?) hemiplicata var. rotunda WINCHELL and ScHuUCHERT, Minnesota Geol.
Surv., vol. 3, pt. 1, p. 383, pl. 30, figs. 32-35, 1895.

Parastrophia hemiplicata rotunda (Winchell and Schuchert) BAsster, U. S. Nat. Mus. Bull.
92, vol. 2, p. 945, IQI5.

P. rotundiformis WitLarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 290,
1928 (not the Virginia specimens).

The shells from McNutt Quarry, near Sharon Springs, Va., and probably
those from Thomas Farm, 3 miles east of Blacksburg, Va., from the Effna
formation undoubtedly belong to Perimecocoelia and should not be identified with
the Minnesota species which comes from the Trenton (Prosser) formation.

The specimen figured is exceptional for the fine development of the interior
details.

Figured specimen.—87600.

Horizon and locality—Prosser formation (Prasopora bed), in Iowa: 14 miles
north of Waukon, Allamakee County.

608 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PARASTROPHINA sp. 1
Plate 106, F, figures 27-32

Shell small, subcircular in outline, brachial valve deeper than the pedicle one;
fold low, marked by 2 strong subangular costae; sulcus moderately deep, nar-
row, marked by a single strong costa; flanks of pedicle valve gently swollen and
with 3 short costae; flanks of brachial valve swollen and with 2 costae.

Measurements in mm.—117169, length 7.3, brachial length 7.4, width 8.6,
thickness 5.7.

Figured specimen.—117169.

Horizon and locality—Lower Martinsburg formation (part with Brogniar-
tella=Salona) in Virginia: On Virginia County Highway 617=910, 0.14 mile
north of Green Mount Church, Broadway (15’) Quadrangle.

Discussion.—This peculiar specimen seems to be a Parastrophina rather than
a Camerella because of its fairly circular form and the shortness of its sulcus and
fold. Naturally, a section of the beak is the only conclusive means of demonstrat-
ing the true generic characters. Possibly it is an aberrant form of the specimens
called Parastrophina hemiplicata, but too few members of that species have been
found in Virginia to permit the making of a series. Wilson (1914, pl. 4, figs.
4, 5) illustrates two specimens of P. hemiplicata having a single costa in the
sulcus, but her specimens are much wider than the Virginia ones.

PARASTROPHINA sp. 2

Shell of about medium size, comparable to the medium-sized specimens of
P., hemiplicata. Transversely and broadly elliptical in outline, paucicostate, the
fold marked by 3 costae and the sulcus occupied by 2 costae. The flanks of the
brachial valves have 2 costae. The specimen suggests Perimecocoelia semicostata,
but the abraded beak of the brachial valve shows alate plates in cross section.
The species is unlike any other Virginia specimens of Parastrophina in the col-
lection in its anterior plication.

Measurements in mm.—111323, length 10.1, brachial length 10.6, width 13.1,
thickness 7.3.

Described specimen,—111323.

Horizon and locality —Oranda formation in Virginia: § mile north of Green
Mount Church, Broadway (15’) Quadrangle.

Family PORAMBONITIDAE Davidson, 1853

Syntrophoidea with thick subparallel plates in both valves defining deep um-
bonal cavities. Exterior usually pitted.

It is doubtful if the shells assigned to Porambonites from the Table Head series
and the upper part of the Pogonip formation in Nevada are actually congeneric
with Porambonites. The known interiors from the Pogonip formation suggest
relationship to Noetlingia rather than Porambonites in the presence of a well-
formed spondylium in the pedicle valve, but they do not have the unusually wide
hinge characteristic of the Russian genus.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 609

Genus PORAMBONITES Pander, 1830

Porambonites PANvER, Geogn. Russ. Reiches, p. 95, 1830.—TrEIcHERT, Neues Jahrb. Mineral.,
Geol. and Paleont., Beil., Bd. 63, Abt. B, p. 177-246, 1930—ScHUCHERT and Cooper,
Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 102, 1932.

PORAMBONITES ? UMBONATUS Cooper, new species
Plate 107, B, figures 4-11

Porambonites ? sp. Utricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 242, pl. 53C,
fig. 21 (not 27), 1938.

Shell large, wider than long, broadly elliptical in outline; valves subequally
convex. Lateral margins broadly rounded ; anterior margin subnasute; anterior
commissure uniplicate. Surface marked by rows of small pits separated by fine
costellae, about 3 of the latter in 1 mm. near the anterior margin of the brachial
valve.

Pedicle valve moderately convex in lateral profile with the maximum convexity
slightly posterior to the middle; anterior profile broadly convex; umbonal and
median regions swollen ; sulcus originating at the middle, shallow, wide, not in-
creasing greatly in depth anteriorly. Tongue long, wide, and narrowly rounded.
Flanks moderately swollen and with moderately steep slopes.

Brachial valve gently convex in lateral profile, with the umbonal region
rounded but the anterior two-thirds flattened. Fold low, somewhat narrowly
rounded, originating at the middle. Umbo and median region inflated; flanks
moderately inflated and with moderately steep slopes. Interior with 2 widely
divergent brachiophore supporting plates.

Measurements in mm.—Holotype, length 23.2, brachial length 22.8, width
27.3, hinge width 12.9, thickness 14.2.

Types.—Holotype: 111373a; figured specimen: 102310.

Horizon and locality—Pogonip group (lower part Rhysostrophia zone) in
Nevada: About 1 mile above the mouth of Ikes Canyon, south side of canyon,
Toquima Range, Roberts Mountains (1°) Quadrangle.

Same formation in California: In Nopah Range, Inyo County.

Discussion.—This species proved to be very rare in the Ikes Canyon locality.
It is characterized by its low fold and shallow sulcus and the fine ornamentation.
If differs from P. reticulatus Pander in the first two of the above characters. It
also differs in having widely divergent brachial plates rather than nearly parallel
ones.

PORAMBONITES ? sp. 1

Plate 108, H, figures 40-42

Represented by one complete but crushed pedicle valve and another frag-
mentary pedicle valve showing sessile spondylium. Syntrophoid in habit, wider
than long, with narrowly rounded sides. Lateral profile moderately convex ; an-
terior profile broadly convex; tongue short, narrowly rounded. Flanks gently
inflated and with moderate slopes. Teeth long, sharp, dental plates strong, an-
terior of sessile spondylium thickened, tapered, and elevated; median ridge not

610 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

protruding anterior to spondylium. Exterior marked with strong rows of pits
separated by narrow costellae.

Measurements in mm.—117177, length 14.0, width 19.1.

Figured specimen.—117177.

Horizon and locality—Pogonip group in California: In the hills on the west
side of Racetrack Valley opposite Quartz Spring, Uhebe Peak (15’) Quadrangle.

Discussion.—This species, of which only a single good pedicle valve is known,
is smaller, more transverse, and more coarsely ornamented than P. ? umbonata.
It is probably from a lower horizon although its precise position is not known.

PORAMBONITES ? sp. 2
Plate 107, A, figures 1-3

Length and width about equal, subhexagonal in outline; sides narrowly
rounded ; posterolateral margins straight, forming an angle of about 120° ; antero-
lateral margins nearly straight and continuous with the sharply pointed tongue.
Umbonal region swollen; sulcus originating on the umbo, shallow, narrow, but
widening and deepening anteriorly but not attaining more than a third the width.
Flanks moderately convex with steep posterolateral slopes. Surface finely costel-
late and pitted but details indistinct in this specimen. Interior with stout dental
plates ; sessile spondylium thickened anteriorly but only slightly elevated at the
front ; median ridge short and thick. Adductor field an oval scar at the anterior
end of the sessile spondylium.

Measurements in mm.—117179, length 19.1, width 20.8.

Figured specimen.—117179.

Horizon and locality—Lower Table Head series in Newfoundland: At Table
Point.

Discussion.—This species has a syntrophoid appearance like that of the pre-
ceding specimen, but the ornamentation seems to be finer and the sulcus is longer
and narrower.

PORAMBONITES ? sp. 3

Plate 106, D, figures 17-24

Three specimens of a third species referrable to Porambonites? were taken
from the Orthidiella zone in Nevada. The fine ornamentation and small pits
suggest that all the specimens are immature. The largest is 8 mm. wide by 6 mm.
long, but the margins are crushed. At its front margin this specimen has 4 or 5
costellae in I mm.

The other two specimens come from the siliceous residues produced by diges-
tion of limestone from the Orthidiella zone east of Frenchman Flat. The largest
specimen is probably a pedicle valve and is 4 mm. wide by 33 mm. long. Inside
it has two somewhat divergent dental lamellae bounding a fairly wide and deep
delthyrial cavity. The floor of the cavity between the plates is slightly thickened.
The third specimen is a fragmentary one and is interpreted as the posterior part
of the brachial valve. In this one the plates are shorter and are inclined toward
each other slightly. The thickening between them is greater than that of the

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 611

former specimen. Neither specimen gives clear indications of its true generic
affinities.

Figured specimens.—111371a,b; 117178.

Horizon and locality—Pogonip group (Orthidiella zone) in Nevada: In the
first ridge east of Frenchman Flat, Las Vegas (1°) Quadrangle; about 1 mile
above the mouth of Whiterock Canyon, Monitor Range, Roberts Mountains (1°)
Quadrangle.

PORAMBONITES ? sp. 4
Plate 107, C, figures 12-14

A crushed specimen of this genus, probably a brachial valve, is 13 mm. long
and 15.8 mm. wide. The valve is swollen and tumid, particularly in the umbonal
region. It is very delicately ornamented, having 4 to 6 costellae in I mm. at the
front. The umbonal region is very finely ornamented. Pits fine, about 5 to the
millimeter at the front.

Figured specimen.—Columbia Univ. 26404 (1093).

Horizon and locality.—Salona formation in Pennsylvania: From the roadside
and small quarry on Pennsylvania Highway 44, 150 yards east of the road to
Oriole, east of Antes Gap, Williamsport, (15’) Quadrangle.

Discussion.—This genus is very rare in any of the known Ordovician rocks
of the eastern United States. The specimen here figured is not well enough pre-
served to describe. Dr. G. Marshall Kay who found it identified the beds from
which it was taken as Upper Rodman, but it occurs in shaly beds that seem best
referred to the lower part of the Salona formation.

Suborder PENTAMEROIDEA Schuchert and Cooper, 1931
Superfamily PENTAMERACEA Schuchert, 1896
Family PARALLELELASMATIDAE Cooper, new family

Shells having a spondylium duplex in the pedicle valve. Brachial valve pro- '
vided with long subparallel plates defining a deep notothyrial cavity.

PARALLELELASMA Cooper, new genus

(Greek parallelos, parallel; elasma, plate)

Shell 4 inch in length or longer, irregularly pentagonal in outline with narrow
beaks and a wide anterior. Rectimarginate to broadly and indistinctly uniplicate.
Biconvex ; valves subequally deep; interareas reduced or obsolete; delthyrium
open ; ornamentation paucicostate, the posterior smooth and the anterior costate.

Pedicle interior with long, curved, slender teeth; notothyrial cavity V-shaped,
defined by thin, delicate dental plates that unite with the median septum to form
a spondylium; anterior of spondylium produced into an elongate, narrowly
rounded, concave tongue. Median septum, high, slender, prolonged anterior tc
the spondylium, not extending to the middle.

Brachial valve with deep and narrow notothyrial cavity; brachiophores short,

612 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

slender, nearly straight ; fulcral plate long and slender forming a deep trough on
the outside of the brachiophore; posterolateral face of brachiophore thickened
and overhanging socket, terminating in a fairly long triangular accessory tooth.
Brachiophore plates long, high, slender, confined to the posterior quarter or less ;
muscle scars not seen.

Genotype.—Parallelelasma pentagonum Cooper, new species.

Discussion.—This genus shows many peculiar characters, both internal and
external. The inner anatomy suggests relationships to Salonia, Metacamarella,
and to Pentamerus itself. It is a remarkably complicated pentamerid for one of
the earliest known.

At first glance the exterior of this genus suggests a camerellid. It is much
narrower and more attenuated at the beaks than is normal in that genus. It also
flares out anteriorly and has straighter posterolateral sides than is usual in
Camerella. The sides of both valves of Parallelelasma are inflected and flattened
or concave. In side view the genus, in its posterior half or two-thirds, would
have a very compressed appearance. The lateral commissure is often broadly
serrate to the point where the pedicle tongue appears. Here the right-angled in-
flection is terminated. At the place where the flattened lateral area terminates is
a narrow gap in the pedicle valve to receive the lobe marking the anterior termi-
nation of the lateral inflection of the brachial valve. The pedicle tongue is short
and broadly rounded. The anterior commissure of the brachial valve is either
rectimarginate or with a broad wave to fit the broadly rounded and serrate pedicle
tongue. The material available does not show a marked anterior broad fold as
is usual in many pentameroids.

The exterior is paucicostate. The posterior half or less is smooth, but the
anterior half or more is marked by broad, low, rounded costae. These present
no unusual features as they appear on the body of the shell, but their terminations
along the anterior margins of both valves are unusual. The fairly strong costae
terminate in deep reentrants, while the grooves between the costae end in long,
sharp projections to produce a jagged margin. The reentrants are of particular
interest.

The costated anterior edge is modified to form an elaborate type of strainer.
The edge of the reentrant is deflected anteriorly to form a low marginal wall.
Across the reentrants of each valve a sort of shelly diaphragm is built slightly
obliquely from the shell surface. These diaphragms across the reentrant com-
bined with the low wall built around the entrant define small chambers at the
ends of the costae. The costae are alternate in arrangement which permits the
acute projection extending from the troughs to fit into the chamber at the end
of the reentrant. The end of the trough fits over the diaphragm closing the re-
entrant. This neat device forms a very efficient straining device for the food-
bearing currents entering the valve.

The interior of the pedicle valve shows no unusual features. The spondylium
is short, fairly shallow and has a long anterior projection at its free end. The
articulating process or tooth is of interest because it is so long and slender.
Another feature of interest in connection with the articulation of the pedicle valve

PART jt CHAZYAN AND RELATED BRACHIOPODS—-COOPER 613

is the slender fold of the shell on the outside of the tooth, which leaves a narrow
slot. This fits against the angulated edge of the brachial valve. No trace of
muscle marks was seen in the spondylium. Narrow interareas appear on each
side of the delthyrial cavity. In old specimens the edge of the shell from the
interarea anteriorly for some distance is flattened and slotted to take the edge of
the opposite valve.

The interior structures of the brachial valve are of considerable interest. These
have a strong resemblance to the cardinalia of Pentamerus and allies, but a num-
ber of important differences can be seen. A long and deep socket divides the out-
side wall of the shell from the brachiophore. The base of the socket is defined
by a deeply concave fulcral plate. The brachiophore is a flat, short, sharply
pointed straight blade bounding the socket and, by its progressive growth, form-
ing a ridge bounding the notothyrium. The outer edge of the brachiophore is
thickened along the socket wall, and opposite the end of the socket it terminates
in a fairly long triangular tooth. This process fits on the inside of the tooth of
the pedicle valve and helps to keep the two valves fitted in place. The brachio-
phore supporting plates are high and slender but short, being confined to the
posterior quarter or less of the valve. Not one specimen in the collection showed
any trace of the muscle field. However, low ridges between the brachiophore
plates on a few specimens suggest that the muscles were confined to the noto-
thyrial cavity.

A structure of interest in the brachial valve is the small ridge on each side of
the beak at the posterior of the valve. This extends obliquely from the beak to
the posterior termination of the socket. It overlies and crosses the posterior end
of the brachiophore. Its use to the brachiopod is not immediately apparent.

The chief similarity between Parallelelasma and Pentamerus is the presence
in each of the nearly parallel brachiophore supporting plates. Here the simi-
larity ends because the cardinalia of the Ordovician genus are not divisible into
inner and outer plates like the cardinalia of Pentamerus. The inner plates of the
latter produce a broad divided hinge plate and shallow notothyrial cavity. Fur-
thermore, the brachial process is given off at the anterior end of the vertical plate
deep inside the valve. Similar difficulties confront a comparison with members
of the Gypidulinae.

The exteriors of the Pratt Ferry genus and Salonia are totally unlike except
in the beak region and the compressed marginal areas. Inside the brachial valve
the similarity consists, in the main, of the presence of two long and subparallel
plates. The cardinalia are actually not very close. The important difference be-
tween them is in the length and form of the brachial process, which is long and
expanded in Salonia but short and straight in Parallelelasma. This feature also
constitutes the chief difference between the Alabama genus and Metacamarella
from the Girvan District, Scotland.

The exterior of Metacamarella is very similar to that of Parallelelasma, but
sufficient characters are known to establish the two as independent genera. The
exterior of Metacamarella is paucicostate like that of the Alabama shell, but the
costae are more concentrated in the median region to form a low, indistinct fold

614 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

on each valve. The sides are compressed in both genera, and the shells are nar-
rowed posteriorly but much more so in the American genus. Cowper-Reed de-
scribes the exterior of Metacamarella as “externally punctate.” All available
evidence indicates that the exterior of Parallelelasma is smooth.

Through the kindness of Dr. Helen M. Muir-Wood of the British Museum,
who has examined the types of Metacamarella preserved in the British Museum,
it is possible now to say that the Scottish genus is not punctate on the exterior.
Dr. Muir-Wood says “Most of the specimens are much decorticated and the
shell tends to weather in overlap scales but these do not appear punctate. The
shell is very finely fibrous, the fibres running obliquely to the surface in the outer
layers, and the broken off ends of the fibres do give the shell a somewhat granu-
lar appearance which may be taken for punctation.”

St. Joseph (1941, p. 399) does not mention presence of exopunctae in his
discussion of the genus. The five sections of the brachial valve illustrated show
well the subparallel plates of the brachial valve, and low ridges between these
plates suggest that the muscles were confined between these plates as in Paral-
lelasma. Unfortunately, no illustration of the “crura” is given.

Metacamarella has short, subparallel plates like those of Parallelelasma in the
brachial valve, but the cardinalia are described as having long, stout crura, re-
curved and diverging at about 60°, close to the hinge line. This is quite unlike
the short, straight brachial processes of the Alabama genus. It is concluded there-
fore that Metacamarella, although superficially like Parallelelasma, is a distinct
genus but probably belongs in the family Parallelelasmatidae.

PARALLELELASMA PENTAGONUM Cooper, new species

Plate 115, H, figure 49; plate 118, B, figures 11-19; plate 119, F, figures 17-31;
plate 121, A, figure 1

Shell thin, elongate, pentagonal in outline with a narrow posterior-but a wide
anterior ; lateral margins obliquely straight for about two-thirds the length; an-
terolateral extremities angulated ; anterior elongate and broadly rounded. Bicon-
vex, the brachial valve somewhat deeper than the pedicle valve; anterior com-
missure rectimarginate to broadly uniplicate. Lateral commissure broadly ser-
rate anteriorly. Beaks low, somewhat closely appressed. Posterior third smooth,
anterior two-thirds marked by broad, low, rounded costae. Lateral edge nar-
rowly angulated and somewhat produced and elevated at its anterior end.

Pedicle valve gently convex in lateral profile; broadly and gently convex in
anterior profile ; umbonal region narrowly swollen ; median region gently inflated ;
margins deflected slightly and separated by a narrow, shallow sulcus; region be-
tween two sulci forming a broad ill-defined sulcus.

Brachial valve gently convex in lateral profile, somewhat more convex pos-
teriorly than in the anterior half; anterior profile broadly and gently convex.
Umbonal region narrowly swollen ; median region gently inflated. Lateral slopes
narrowly rounded and precipitous. Costae anteriorly forming an ill-defined fold.

Interior as defined under the genus.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 615

Measurements in mm.—

Brachial Greatest
Length length Midwidth width Thickness
Paratype (pedicle valve 117156e).. 13.7 ? 10.0 14.8 5.8
7 (brachial valve 111329).. e 14.3 11.5 14.7 5.5?

Types.—Holotype: 117156-1; figured paratypes: 111329, 117155b,c,e-g,
117156a,c-h,j; unfigured paratypes: 117155a,d, 117156b,i,k,m.

Horizon and locality—Lower 3 feet of the Pratt Ferry formation in Alabama:
0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—No other shell is quite like this one except for species of Idio-
strophia. The latter have the elongate form and pentagonal outline of Parallelel-
asma and the peculiar flattening of the margins, but the interiors of the two
genera are so different that little confusion will result.

Genus SALONIA Cooper and Whitcomb, 1933
SALONIA MAGNAPLICATA Cooper and Whitcomb
Plate 107, D, figures 15-21

Salonia magnaplicata Cooper and Wutrcoms, Journ. Washington Acad. Sci., vol. 23, No. 11,
PP. 500-503, 1933.

Figures of this species are introduced for comparison with those of Parallel-
elasma. The presence of the long subparallel brachiophore supporting plates in-
dicates relationship between the two genera. They differ mostly in exterior orna-
mentation and form but also in one important interior feature. The brachial
processes of Salonia are long, flat, somewhat curved blades, whereas those of
Parallelelasma are short, straight, and blunt.

Types.—Holotype: 85422a; paratypes: 85422b-e,p.

Horizon and locality Salona formation (12 feet above the base) in Pennsyl-
vania: Along the railroad beside Fishing Creek in Salona, Clinton County, Lock
Haven (15’) Quadrangle.

DIDYMELASMA Cooper, new genus

(Greek didymos, twin; elasma, plate)

Shell small, syntrophoid in appearance; uniplicate ; surface paucicostate. Beaks
small, interareas obsolete. Delthyrium open.

Pedicle interior provided with a narrow, short spondylium supported by a
long, thin median septum.

Brachial interior with two long parallel plates supporting a long, thin, slightly
curved brachial process, which is attached to a triangular socket plate located
between the posterior edge of the brachial process and the posterior edge of the
valve. Muscle scars not seen.

Genotype-——Didymelasma longicrurum Cooper, new species.

This genus is so far known only from the species described herein. It is a
small shell having the appearance of a syntrophid. It has small beaks with no
interarea remaining as far as can be determined, The species is not unlike that

616 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

of Neostrophia gregaria from the Bromide formation at Rock Crossing, Okla.,
but it can be readily differentiated from any of the known camerellids except
Metacamarella, Salonia, and Parallelelasma by its brachial interior.

Didymelasma differs from Metacamarella in the form of the valves, the latter
genus being elongate and flaring anteriorly. It differs internally in having a long
and nearly straight brachial process rather than a long, curved one as described
for Metacamarella.

Salonia is totally unlike Didymelasma in its transverse form and the strong
anterior lobation. The brachial interior resembles that of Salonia in the presence
of the long brachial process, but that structure in Didymelasma is given off from
a more anterior point than in Salonia and the process is nearly straight.

The exterior of Parallelelasma has a distinctly pentagonal outline with the
greatest width anterior to the middle and the shell strongly angulated at the place
of maximum width. In these respects it is entirely unlike Didymelasma. Inside
the brachial valve the position and great length of the brachial process in Didy-
melasma are important differences.

DIDYMELASMA ABRUPTUM Cooper, new species
Plate 120, E, figures 30-33

Shell small, subcircular in outline with length and width nearly equal; sides
rounded ; anterior commissure uniplicate ; surface smooth.

Pedicle valve moderately convex in lateral profile and fairly strongly convex
in anterior profile. Umbonal, median, and flank regions swollen ; sulcus originat-
ing about 14 mm. anterior to the beak, shallow and narrow but widening an-
teriorly although not deepening greatly in the same direction. Old specimens
with a faint costa at the anterior end of the sulcus. Tongue short. Interior with
a median septum extending to about the middle.

Brachial valve gently convex in lateral profile, greatest convexity in the pos-
terior third, anterior third somewhat flattened. Anterior profile broadly convex ;
umbonal and median regions full. Sulcus originating between the umbo and the
middle, fairly strongly elevated at the front, flattened on top. Flanks swollen
but strongly depressed below the level of the fold. Interior with two short, sub-
parallel plates.

Measurements in mm.—

Brachial
Length length Width Thickness
Pedicle valve (C.U. 26403(928)a)......... 5.5 ? 5.8 1.9?
Brachial valve (C.U. 26403(928)b)........ ? 5.3 5.3 1.7
( ©) GG. 26403 (028) ©) iit insta ss. 4 5.8 6.1 ?

Types.—Holotype: Columbia Univ. 26403 (928)b; figured paratypes: Colum-
bia Univ. 26403 (928)a,c.

Horizon and locality—Rockland formation in Ontario, Canada: Northeast of
Gretna.

Discussion.—This is a larger species than the D. longicrurum of the Lebanon
formation. Besides size it differs in the fold and sulcus, those of the Ontario form

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 617

being longer and more elevated. The sulcus of the Lebanon species is short and
deep. The Tennessee species have a tendency to some costation on the front of
the valves, which is seen only indistinctly in the Ontario form.

DIDYMELASMA LONGICRURUM Cooper, new species
Plate 120, D, figures 19-29

Shell small, syntrophoid in outline and profile, subcircular; sides rounded;
anterior margin truncated; anterior commissure somewhat narrowly uniplicate ;
surface smooth but many specimens with indistinct costae in adults, usually 2
on the fold, I in the sulcus, I on the flanks near the middle.

Pedicle valve fairly strongly convex in lateral profile ; broadly and moderately
convex in anterior profile. Umbonal region somewhat narrowed at the beak;
median region inflated; sulcus originating just anterior to the middle, abruptly
deepening to become moderately deep at the margin; sulcus bounded by nar-
rowly rounded costae; flanks somewhat swollen and with steep lateral slopes.
Interior with small spondylium and long, thin median septum.

Brachial valve moderately convex in lateral and anterior profiles and with a
depth about equal to that of the pedicle valve. Umbo narrow; median region
swollen ; fold narrow and rounded, moderately strongly elevated, originating at
about the middle; sides of fold defined by moderately deep sulci. Flanks only
gently inflated and with moderate lateral slopes. Interior with 2 parallel brachial
plates and long, nearly straight brachial process.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Eloltyper sot aweedy. Mee 375 ay 4.2 0.5 2.3
Paratype {(rr7nssd) ais. FOske 3.5 3.4 3.75 0.49 1.3

Types.—Holotype: 117158c; figured paratypes: 117158a,b,d; unfigured para-
types: 117158¢,f.

Horizon and locality—Upper part of the Lebanon formation with Doleroides
tennesseensis Cooper in Rutherford County, Tennessee: On U. S. Highway 41,
3 mile southeast of Knox Branch, 9 miles southeast of Murfreesboro.

Discussion.—This species is characterized by its small size and syntrophoid
form. It has a deep sulcus on the pedicle valve and a strong, elevated fold on
the opposite valve. These latter features are more pronounced than in D. ab-
ruptum which has a broader fold and sulcus.

Superfamily RHYNCHONELLACEA Schuchert, 1896
Family PROTORHYNCHIIDAE Schuchert, 1896

Rhynchonellacea lacking complete deltidial plates but have dental lamellae, long
curved crura, but no median septum or cruralium.
Subfamily PrororHyncuiinar Schuchert, 1806

Protorhynchiidae of uncertain structure.

618 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genus PROTORHYNCHA Hall and Clarke, 1893
Protorhyncha HAutt and CLARKE. Pal. New York, vol. 8, pt. 2, p. 180, 1893.

It is pointed out below that the type specimens of Protorhyncha dubia Hall
have long been lost and the genus is virtually unknown. Raymond has pointed
out that the type specimens may actually have been young hebertelloids, which
makes the genus still more confusing. The facts are mentioned and discussed
below. Until the types are found, or other specimens that can be definitely identi-
fied as P. dubia, the true characters of the genus will not be known.

Genotype.—Atrypa dubia Hall, Pal. New York, vol. 1, p. 21, 1947.

Subfamily ANCISTRORHYNCHIINAE Cooper, new subfamily

Protorhynchiidae with characters of the family.

Genus ANCISTRORHYNCHA Ulrich and Cooper, 1942

Protorhyncha (part) Hatt and Crarke, Pal. New York, vol. 8, pt. 2, p. 180, 1894.—
Raymonp, Ann, Carnegie Mus., vol. 7, No. 2, p. 226, 1911—Hayes and ULricu, Geol.
Atlas U. S., Folio 95, Faunal Chart, 1903.

Ancistrorhyncha UtricH and Cooper, Journ. Paleont., vol. 16, No. 5, p. 624, 1942.

Shell small, rhynchonelloid in outline and profile, valves subequal in depth;
biconvex in profile; anterior commissure uniplicate. Surface marked by fine
radial costae. Impunctate.

Pedicle valve with open delthyrium, vestigial interarea, incurved beak. Del-
thyrial cavity deep, bounded by strong dental plates separated from sides of valve
by deep umbonal cavities ; teeth small, curved. Details of musculature unknown.

Brachial valve with divided hinge plate; sockets deep, defined by a fulcral
plate and a thin but elevated socket ridge; outer hinge plate slightly concave ;
crural base forming inner edge of outer hinge plate; crura long and slender,
ending in a broad hooklike expansion pointing anterolaterally and at about right
angles to the crus. Musculature unknown; median septum absent.

Genotype.—Ancistrorhyncha costata Ulrich and Cooper, Journ. Paleont.,
vol. 16, No. 5, p. 625, pl. 90, figs. 25-27, 30-31, 1942.

Discussion.—This genus is characterized by its rhynchonelloid exterior, fine
regular costae, open delthyrium, strong dental plates, divided hinge plate, and
long crura. It is distinguished from Rhynchotrema and Rostricellula by absence
of a septum and cruralium and the fine, even nature of the ornamentation.

The members of this genus were formerly classified under the name Proto-
rhyncha, but this name is no longer available for two reasons. First, the type
species is unrecognizable, as type specimens have long been lost; second, the
species used by Hall and Clarke for their description of the genus is still invalid.

Hall and Clarke designated Atrypa dubia Hall as the type of the new genus
Protorhyncha, but as pointed out by Raymond (1911) this species is unrecogniz-
able. Hall’s definition of the species is very vague, his figures are poor indeed,
and he states that the specimens are in the nature of casts, all of the shell having
been removed. Only two or three individuals of the species are said to have been

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 619

known. Raymond suggests that “the original specimen may have been a young
Camarotoechia plena, a young Camarotoechia pristina, or a broken and exfoliated
Hebertella.”

Although Hall and Clarke named A. dubia as type of their genus, they realized
that the species on which it was based was poorly described because they did not
use the type specimens to derive their generic diagnosis. Instead they used speci-
mens from “the gorge of the Kentucky River, at High Bridge, Kentucky” which
they erroneously identified as Hall’s “Atrypa” dubia. This procedure of course,
under the rules, has no bearing on the validity of their selection of A. dubia as
the type of the genus.

To add still further to the confusion Hall and Clarke failed to refigure Atrypa
dubia and also published no figures of the Kentucky specimens from which they
derived their generic description. Instead they illustrated a Silurian species
called Protorhyncha aequiradiata Hall which actually shows the chief generic
characteristics of Rhynchotrema or Camarotoechia (pl. 56, fig. 8). The generic
diagnosis and the species on which Protorhyncha is based thus prove to be vague
and poorly founded, and this is true also of the species proposed by Raymond
to serve as neotype.

In his discussion of Protorhyncha Raymond suggests that, inasmuch as the
type species P. dubia is unrecognizable, the species from which Hall and Clarke
derived their generic diagnosis be used as the type of the genus. This is the
species identified by Ulrich as Rhynchonella ridleyana (Safford). The name
Rhynchonella ridleyana was first used by Safford (1869, p. 287) without defini-
tion or other designation than to list it as having been taken from the Pierce and
Ridley limestones. When Hall and Clarke prepared their generic description of
Protorhyncha, they stated that their information was derived from specimens
coming from High Bridge, Ky., but failed to use any specific name in connec-
tion with them, and it is therefore at least implied that they identified their speci-
mens with P. dubia rather than P. ridleyana. In the Columbia Folio Ulrich
(1903) uses the new combination Protorhyncha ridleyana for the first time in a
list of characteristic fossils of the Ridley limestone but failed to furnish a defi-
nition of the species. This combination has been in use for some time not only
for specimens from the Ridley limestone of central Tennessee but also for speci-
mens from High Bridge, Ky. Although the name has long been in use, no defini-
tion of it has ever been prepared.

From the above remarks it will be seen that the definition of Protorhyncha
is based on misidentified fossils and that the named type is unrecognizable. Fur-
thermore, the attempt to establish P. ridleyana as type of the genus fails because
that species is still a nomen nudum and without validity. The name Protorhyncha
thus proves to be one of very dubious value, and it seems best to leave it with
the unrecognizable specimens for which it was proposed and to supply a new
name for the splendid material of several species that had hitherto been placed
in Protorhyncha.

Ancistrorhyncha at present has no close relatives to which it may be compared.
It is distinctly not the first of the rhynchonellids but a fairly highly specialized

620 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

brachiopod. The hooklike extension on the crura may be seen also in well-
preserved specimens of Lepidocyclus, but there the similarity ends. The orna-
mentation of the genus is unlike that of typical rhynchonellids, and the absence
of a septum in the brachial valve is also atypical for rhynchonellids.

ANCISTRORHYNCHA AUSTRALIS (Foerste)
Plate 127, E, figures 28-32; plate 127, F, figures 33-41; plate 127, G, figures 42-46

Protorhyncha dubia Hatt and CLARKE (part), Pal. New York, vol. 8, pt. 2, p. 180, 1894.

Protorhyncha ridleyana RayMonp (part), Ann. Carnegie Mus., vol. 7, No. 2, p. 226, I191t.

Catazyga uphami-australis Forrste, Bull. Sci. Lab., Denison Univ., vol. 16, p. 31, pl. 2,
figs. 19a, b; pl. 3, figs. 14a-c, 1910.

Shell small, subcircular in outline; beak forming an obtuse angle; sides some-
what narrowly rounded ; front margin gently rounded. Surface marked by broad,
rounded costae separated by spaces narrower than the costae, about 54 costae in
all, with 11 in the sulcus.

Pedicle valve moderately convex in lateral profile with the greatest convexity
in the posterior half; umbonal region swollen; beak strongly curved over the
brachial umbo ; sulcus short, shallow,’ originating slightly anterior to the middle,
occupying less than half the width; tongue short, rounded. Flanks rounded, with
fairly steep slopes to the margins.

Brachial valve fairly evenly convex in lateral profile, broadly convex in an-
terior profile. Umbonal and median regions swollen; fold a low, gentle swelling
originating anterior to the middle, narrow. Flanks rounded, depressed below
the fold; lateral slopes moderate.

Measurements in mm.—

Brachial
Length length Width Thickness
TL CEOW Dees uaiscye stersisepts etcemynw: stele as is 7.0 7.6 9.0 5.5
Fivpotype, Cini Zora) ena wists he as 7.7 6.7 8.4 4-3
. CTTTADIC) 24, he: PP 8.7 7.8 10.6 5.5

Types.—Lectotype: 87043a; figured hypotypes: 111291a-c, Columbia Uni-
versity (no number).

Horizon and locality—Camp Nelson formation in Kentucky: At High Bridge,
Harrodsburg (30’) Quadrangle.

Lebanon formation in Tennessee: Opposite the Fairview Service Station on
U. S. Highway 70N, just west of Rome and 11.6 miles east of Lebanon, Smith
County.

Nealmont formation in Pennsylvania: 1 mile west of Tusseyville, Centre Hall
(15’) Quadrangle ; south of Pa. C. Ry., Bellefonte, Bellefonte (15’) Quadrangle.

Discussion.—This species is characterized by its soft, rounded outlines, nar-
row fold and sulcus, and the fine, crowded costae. It is most like A. costata but
differs from that species in its narrower fold and sulcus and the finer ornamenta-
tion. The fact that the finely costate forms outside of the High Bridge area are
post-Ridley and Wardell, suggests that the level containing this species at High
Bridge belongs to the Lebanon, Nealmont, and lower Trenton.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 621

ANCISTRORHYNCHA COSTATA Ulrich and Cooper
Plate 126, B, figures 6-9; plate 127, H, figures 47-52; plate 127, J, figures 58-62; plate 120, A,
figure 1; plate 129, B, figure 2; plate 129, C, figures 3-8; plate 129, D, figures 9-13;
plate 129, E, figures 14-19; plate 129, F, figures 20-25; plate 129, H, figures 33-38
Ancistrorhyncha costata Utricu and Cooper, Journ. Paleont., vol. 16, No. 5, p. 625, pl. 90,
figs. 25-27, 30, 31, 1942.

Shell small, valves subequal in depth, subtriangular to subpentagonal in out-
line ; beak slightly greater than a right angle; sides diverging and straight from
beak to about the middle where the shell attains its maximum width, sides
rounded at middle; front margin truncated. Surface marked by low, rounded
costae separated by spaces narrower than the costae. The sulcus is marked by
6 to 10 costae, the fold by 7 to 11 costae, and the flanks bear about 13 ribs.

Pedicle valve moderately convex in lateral profile with the greatest convexity
located in the tumid posterior half. Sulcus originating at about the middle, shal-
low, with a short, narrowly rounded tongue; sulcus occupying as much as half
the width at the front. Flanks fairly strongly rounded and with moderately steep
slopes.

Brachial valve moderately convex in lateral profile and with the maximum
curvature at about the middle; anterior profile fairly strongly rounded. Umbo-
nal and median regions swollen; fold originating slightly anterior to the middle,
low in most specimens and in some scarcely distinguishable. Flanks moderately
rounded and with moderately steep slopes.

Interior: Dental plates strong, separated from inner wall of valve by umbonal
cavities ; crura long and slender.

Measurements in mm.—

Brachial

Length length Width Thickness

Bioletype? SS OH 7.8 6.7 8.6 5.0
Hypotype (117204b)............... 8.5 Vey | 10.0 6:0 1%

* CERO G A ton As 3 riders tee 9.0 8.0 10.0 6.5

< Ag Te eer eae ie 7.4 6.8 7.7 4.4

Ke adhe 7) Cian ice v pe 6.5 77. 4.9

2 RIDETOO) Steed eee 6.9 6.6 7.6 4.8

? ChI7200d) et. 29S. todd 8.0 7.4 8.9 z

5 (TI72OGH eC ds ti). idapya ais 6.6 5.0 7 i 3.8

Types.—Holotype: 108203 ; paratypes: 108204a-l ; 111183; figured hypotypes:
II119Q6, 117204a,b,c, 117205, 117206b,c, 117207, 123291a, Columbia Univ.
25880(2120) ; measured hypotypes: 117206a,f.

Horizon and locality —Ridley or Murfreesboro formation in Sequatchie Val-
ley, Tenn.: 14 miles southeast of Hembree Mill, Pikesville (15’) Special Quad-
rangle; Crystal Creek, 5 miles south of Pikeville; Sequatchie Valley ; Murfrees-
boro; Ridley formation: 0.6 mile south of Chappel Hill Methodist Church on
Tennessee Highway 28, 1 mile south of its junction with Tennessee Highway 8.

Same formation in Rutherford County, Tenn.: Stone River bridge on Ten-
nessee Highway 96, 1 mile west of Murfreesboro; east side of Marshall Knobs
about 5 miles south of Murfreesboro.

622 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pierce formation in Rutherford County, Tenn.: at Nice’s Mill, west fork of
Stone River, 8 miles (airline) northwest of Murfreesboro; Pierce Mill at Walter-
hill, on Tennessee Highway 10, 74 miles north of Murfreesboro.

Wardell part of Dryden formation in Viriginia: In north quarry on Station
Creek, 4 mile south of U. S. Highway 58, 2 miles east of Cumberland Gap,
Wheeler (T.V.A. 153-SE) Quadrangle.

Wardell and Wardell part of Dryden formation in Tennessee: 0.3 mile south-
west of Little Barren Church, northwest corner of the Powder Springs (T.V.A.
154-SW) Quadrangle; Jacksboro, Jacksboro (T.V.A. 136-SW) Quadrangle;
I mile west of Lone Mountain, Tazewell (T.V.A. 154-NE) Quadrangle; north
of canyon of Gap Creek, 14 miles west of Arthur, Cumberland Gap (T.V.A.
153-SW) Quadrangle; Raccoon Valley, 5 miles south of Clinton, Clinton
(T.V.A. 137-SW) Quadrangle; 1 mile west of crest of Missionary Ridge, Chat-
tanooga, Chattanooga (30’) Quadrangle; hill back of Camp Loyston, Maynard-
ville (30’) Quadrangle; Little Mulberry Creek on road up Sycamore Valley,
Back Valley (T.V.A. 161-SE) Quadrangle.

Peery formation (lower 8 feet) in Virginia: South side of Peery Lime Com-
pany Quarry on Virginia Highway 61, North Tazewell, North Tazewell (T.V.A.
217-NE) Quadrangle.

Ridley formation in Kensington (T.V.A. 106-SE) Quadrangle, Georgia:
10 miles south of Chickamauga; on U. S. Highway 27, 4.2 miles north of Rock
Spring; quarry on the west side of the road, 14 miles south-southeast of Cove
Church, 5 miles south of Chickamauga.

Hostler formation in Pennsylvania: In the section between Rodman and
Roaring Spring, Hollidaysburg (15’) Quadrangle; National Lime Quarries,
Shrader Station= Naginey P. O., Lewistown (15’) Quadrangle.

Bromide formation (Pooleville member) in Oklahoma: 5 feet below the Viola
contact in the road cut on Oklahoma Highway 99, NWiNE4SW3 sec. 12,
T. 1 N., R 6 E., 3 miles south of Fittstown, Pontotoc County. In Murray
County, Okla., at base of bed 2 on Spring Creek, sec. 17, T. 2 S., R. 1 W.; in
the Tetradium beds in the top 10 feet on Colbert Creek, SESNE}4 sec. 15, T. 1 S.,
R. 1 E., 3 to 4 miles southwest of Davis; E4 sec. 1, T. 2 S., R. 2 W., 3 miles
east of Pooleville; 4 miles west and 2 miles south of Davis.

Pamelia formation (50 inches from top) in New York: Quarry east of rail-
road bridge north of Mill Creek in Lowville, Lowville (15’) Quadrangle.

Lower Plattin group (Bloomsdale formation) in Missouri: On the Heck place,
14 miles south-southeast of River aux Vasses, Weingarten (15’) Quadrangle.

Plattin group in Arkansas: On east side of Arkansas Highway 69, 2 miles
north of Cushman, Batesville (30’) Quadrangle.

Discussion.—The material on which this species is based consists of fairly well
preserved silicified specimens etched from limestone, as well as excellent speci-
mens weathered from shaly seams in calcilutite or from calcilutite. The silici-
fied specimens preserve the long crura of the brachial valve with the hooklike
process on the extremity.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 623

This species is characterized by its large size, attaining about the maximum
known dimensions for the genus, the wide fold and sulcus, and the subtriangular
form. It differs from A. australis (Foerste) by its stronger ornamentation, less
strongly incurved beak, and less tumid brachial valve.

ANCISTRORHYNCHA CRASSA Cooper, new species
Plate 99,1, figures 53-61; plate 127, D, figures 20-27; plate 127, I, figures 53-57;
plate 186, G, figures 26-31

Shell of about the usual size for the genus, slightly wider than long with
the greatest width at about the middle. Beak obtuse, posterolateral margins
short; lateral margins narrowly rounded; anterior margin truncated. Surface
marked by about 30 rounded costae separated by spaces equal in width to the
width of the costae. Four or five costae occupy the sulcus, 5 or 6 are on the fold,
and about 12 on the flanks.

Pedicle valve moderately convex in lateral profile with the greatest convexity
at about the middle; beak moderately incurved; sulcus originating about one-
third the length from the beak, shallow and narrow, occupying less than half the
width at the front; tongue short and narrowly rounded. Flanks slightly convex
and with moderate slopes to the margins, Umbonal region and posterior half of
valve somewhat inflated.

Brachial valve of about the same depth as the pedicle valve, moderately con-
vex in lateral profile and with greatest convexity in the umbonal region. An-
terior profile only moderately convex. Umbo marked by a shallow and narrow
sulcus for one-third the length from the beak, after which the median fold de-
velops; fold low, narrow, posteriorly spreading at the front; flanks broad and
rounded in profile, with moderate slopes.

Measurements in mm.—
Brachial

Length length Width Thickness
Tlofoty pe eee es POI: Pe 8.2 7.5 9.5 5.0
Paratype (Er 7Bpye wee. 7.0 8.5 7.9 4.6

Types——Holotype: 111178a; figured paratypes: 111178b; I11184a, 117208a;
Columbia Univ. 26407(1016) ; unfigured paratypes: 111184b, 117208b.

Horizon and locahty.—Peery formation in Tennessee: On Clinton (T.V.A.
137-SW) Quadrangle, 7 miles southwest of Clinton; top of hill north of Elza
Gate, Oak Ridge, Clinton (T.V.A. 137-SW) Quadrangle.

Wardell part of Dryen formation in Tennessee: Section 1 mile west of Lone
Mountain, Tazewell (T.V.A. 154-NE) Quadrangle.

Ridley formation in Tennessee: On Tennessee Highway 28, 0.6 mile south of
Chappel Hill Church, 1 mile south of junction with Tennessee Highway 8, Daus
(T.V.A. 104-SW) Quadrangle.

Hostler ? formation in Pennsylvania: 1 mile south of Covedale, Blair County.

Discussion——tThis species differs from all other described ones in the strength
of the costae covering the surface. In this repect it resembles A. missouriensis,
but in that species the fold and sulcus are much less well defined than in A. crassa.

624 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ANCISTRORHYNCHA GLOBULARIS Cooper, new species
Plate 128, B, figures 6-9

Shells small, rotund and circular when young, somewhat wider when adult;
length and width about equal; beak obtuse; sides rounded; front margin trun-
cated. Surface costate, with 18 to 24 costae, of which 4 to 6 occupy the sulcus.

Pedicle valve evenly and fairly strongly convex in lateral profile with the great-
est convexity at about the middle. Beak short and inconspicuous, incurved ; um-
bonal and median regions swollen; sulcus originating at the middle, shallow,
equal to about half the width at the front margin. Flanks rounded and with steep
lateral slopes.

Brachial valve not quite so deep as the pedicle valve; moderately convex in
lateral and anterior profiles; median and umbonal regions slightly swollen ; fold
low, often difficult to distinguish; flanks well rounded and steep lateral slopes.

Measurements in mm.—Holotype, length 4.8, brachial length 4.1, width 5.0,
thickness 3.2.

Types.—Holotype: 111278a; unfigured paratypes: 111278b,c.

Horizon and locahty.—Bromide formation (Pooleville member) just below
the Viola in Oklahoma: 4 miles west and 2 miles south of Davis, Murray County.

Discussion.—This species is the smallest of those yet described and differs from
all others in its globular form, straight front, and considerable thickness. It is
readily distinguished from A. costata, with which it occurs, by its smaller size
and less transverse shells.

ANCISTRORHYNCHA MISSOURIENSIS Cooper, new species
Plate 128, D, figures 14-19

Shell of about usual size for the genus, subtriangular in outline; length and
‘width about equal; beak forming about a right angle; sides somewhat narrowly
rounded; anterior margin gently rounded. Surface costate, about 22 rounded,
fairly strongly elevated costae with narrower interspaces; 4 costae occupy the
sulcus, and 5 occur on the fold.

Pedicle valve equal to the brachial valve in depth, moderately convex in lateral
profile and with the greatest convexity in the posterior half. Umbonal region
narrowly swollen; sulcus originating about the middle, poorly defined. Flanks
slightly convex, sloping steeply to the margins.

Brachial valve gently convex in lateral profile and with the maximum con-
vexity located in the posterior half; umbonal and median regions somewhat swol-
len and anterolateral areas slightly less tumid. Fold scarcely visible, originating
at about the middle and occupying less than half the width at the front. Flanks
moderately convex with fairly steep slopes to the margins.

Measurements in mm.—-Holotype, length 7.7, brachial length 6.7, width 7.5,
thickness 5.3.

Types.—Holotype: 111284a; unfigured paratype ; 111284b.

Horizon and locality—Rock Levee formation in Missouri: Junction State

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 625

Highway 74 and U. S. Highway 61 at Rock Levee, 34 miles southwest of Cape
Girardeau, NW. corner sec. 24, T. 30 N., R. 13 E., Cape Girardeau (15’)
Quadrangle.

Discussion ——This species may be recognized by its strong costae and by the
slight development of the fold and sulcus, in which respect it differs from
A. crassa.

ANCISTRORHYNCHA ? PERPLEXA Cooper, new species
Plate 127, C, figures 14-19

Shell small for the genus, subcircular in outline; apical angle about 115°;
sides narrowly rounded; anterior margin truncated. Anterior commissure
strongly uniplicate. Surface costate, more strongly than usual in the genus, costae
narrowly rounded with deep separating grooves; 4 costae on the fold, 3 in the
sulcus, and 7 or 8 on the flanks.

Pedicle valve fairly strongly convex in lateral profile and with the greatest
convexity at the middle; anterior profile moderately and broadly convex ; umbo
narrowly swollen ; median region swollen ; sulcus originating at about the middle,
moderately deep, occupying slightly less than half the midwidth; tongue moder-
ately long; flanks somewhat inflated and with moderately steep slopes. Beak
long and strongly incurved.

Brachial valve slightly deeper than the pedicle valve, strongly convex in both
profiles ; umbo flattened and sulcate; sulcus short, shallow, and disappearing at
the middle where the fold originates ; fold short and low; flanks swollen and with
steep lateral slopes.

Measurements in mm.—Holotype, length 6.0, brachial length 5.5, width 6.4,
thickness 4.5.

Type.—Holotype: 111297.

Horizon and locality—McLish formation in Oklahoma: In sec. 35, T. 1 S.,
R. 7 E., 1 mile southwest of McLish Ranch house, west of Bromide, Johnston
County.

Discussion—This species is characterized by its sharp and strong costae, the
moderately deep sulcus, and sharply defined fold. These features, not usually
seen in Ancistrorhyncha, distinguish it from all known species of the genus. A
median septum was not observed in the brachial valve, the presence of which
could relate the species to Rostricellula or allied forms. This species is therefore
tentatively placed in Ancistrorhyncha.

ANCISTRORHYNCHA ? VACUA Cooper, new species
Plate 128, C, figures 10-13

Shell small, subtriangular to subpentagonal in outline. Posterolateral margins
straight forming an angle of go° at the beak. Sides narrowly rounded and with
the greatest shell width located slightly anterior to the middle. Anterior margin
broadly rounded. Anterior and lateral margins faintly costate, posterior half (?)

626 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

smooth. Sulcus occupied by 2 or 3 costae, and 3 or 4 occur on the brachial fold.
The flanks are marked by 2 or 3 costae.

Pedicle valve in lateral profile fairly strongly convex in the posterior half but
somewhat flattened in the anterior portion. Anterior profile moderately convex
with a slight depression at the middle in some specimens. Sulcus short, wide,
and shallow, producing a short, broadly rounded tongue. Areas bounding sulcus
moderately convex, while the flanks of the shell are moderately convex and with
steep lateral slopes.

Brachial valve strongly convex in lateral profile with the maximum convexity
slightly posterior to the middle. Anterior profile moderately convex. Fold low
and not prominent, defined at the anterior only. Body of shell slightly swollen
and with steep lateral slopes.

Measurements in mm.—

Brachial
Length length Width Thickness
Holbtypervn.insun aloes «Levetal oh 4.8 4.3 5.0 2.9
Paratype «(GET 2R2b ici bes aciabisehee 4.8 4.3 5.4 22
* GE D620).. wietact tlie deat 4.5 3.9 4.2 2.8

Types.—Holotype: 111282a; unfigured paratypes: 111282b,c.

Horizon and locality—Mingan formation (zone A5) in Quebec, Canada:
Mingan (or Bald Island), Mingan Islands, St. Lawrence River.

Discussion.—These little shells combine some of the exterior features of
Ancistrorhyncha and Camerella. The costation is like that of Camerella in its
shortness and strength. Most other species of Ancistrorhyncha are completely
costate and the costae are generally finer and more numerous. The folding of
this little species is, nevertheless, like that of Ancistrorhyncha. The determining
factor for placing the species in Ancistrorhyncha is its internal structure—or in
this case, lack of internal structure. The shells are filled with crystalline calcite,
a fact that makes determination of the interior details very difficult. Twenhofel
(Twenhofel and Whiting, 1938, p. 54) assigned specimens from the same place
and horizon to Rhynchocamara varians and regarded them as the young of that
species. Twenhofel stated that the specimens had been entirely replaced by
crystalline calcite. This is not true; the shells have been filled but not replaced
by the mineral because the fibrous nature of the shell is still retained.

In order to study these specimens, they were immersed in water and examined
in a strong light. By this method a certain translucency of the outer shell was
obtained. If these specimens belonged to the genus Rhynchocamara, the strong
median septum of both valves would have been visible. The brachial valve re-
vealed no trace of septa which would have been clearly visible in the few shells
filled by opaque calcite. The pedicle valves showed short dental plates. This
combination of characters in the pedicle valve and lack of septa in the brachial
valve in connection with the Ancistrorhyncha-like external expression led to the
placing of the species in that genus.

This species differs from all those herein described by its naked umbos, strong
costae, and general resemblance to Camerella.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 627

DREPANORHYNCHA Cooper, new genus
(Greek drepanon, sickle; rhynchus, beak)

Shell rhynchonelloid in outline and profile; hinge narrow, both valves pro-
vided with narrow interareas ; delthyrium open; anterior commissure uniplicate ;
surface costate; shell fibrous, impunctate.

Pedicle valve with deep delthyrial cavity bounded by slightly convergent dental
plates; teeth large; musculature indistinct. Brachial valve with deep sockets,
divided hinge plate with concave outer hinge plates, long crural bases, and long,
slender, curved crura. Crural bases united with posterior of notothyrial cavity
and lying obliquely under the notothyrial edge. Median septum lacking.

Genotype——Porambonites ottawaensis Billings=Drepanorhyncha ottawaensis
(Billings), Paleozoic fossils, vol. 1, p. 140, fig. 117 (adv. sheets), 1862.

Discussion—This species was at first mistakenly placed under the genus
Porambonites with which it has nothing in common externally or in the interior.
Later it was transferred to Camerella, but it is no more at home in that niche
than it is in the first category. Later Schuchert and Cooper, 1932 (plate 16)
transferred P. ottawaensis to Orthorhynchula because it possessed a pedicle inter-
area and a divided hinge plate with concave crural supports. Reexamination
of the types of P. ottawaensis and additional material, together with study of
better interiors of Orthorhynchula, show that the two types have little in common
besides the interareas.

Drepanorhyncha is characterized by the presence in the pedicle valve of
elongate dental plates spaced fairly closely together making a deep and narrow
delthyrial chamber. The muscles are separated by a low and narrow median
ridge. In the brachial valve the plates bearing the crura are concave and are
supported by attachment to the posterior of the notothyrial cavity and the edge
of the notothyrial margin facing the brachial valve. The crura are exceptionally
long and slender. No median septum nor cardinal process is present.

In contrast to Drepanorhyncha the dental plates of Orthorhynchula are short
and receding and are attached closely to the lateral walls of the valve. In the
brachial valve the hinge plate is divided into two concave outer hinge plates
which are concave and resemble those of Drepanorhyncha although they lie in
the valve differently, presenting the concave face toward the pedicle valve,
whereas in Drepanorhyncha the same plates lie obliquely facing each other. In
Orthorhynchula, furthermore, the hinge plates are attached to a median swelling
that bears a typical orthoid cardinal process situated between the two plates. The
cardinal process has a stout shaft and a compressed and crenulated myophore
like that of Hebertella. The median ridge, although low, is present and prominent.

As far as known the genus Drepanorhyncha occurs only in Trenton rocks in
New York and Ontario.

DREPANORHYNCHA AMBIGUA (Hall)
Plate 128, G, figures 37-39

Airypa ambigua Hatt, Pal. New York, vol. 1, p. 143, pl. 33, figs. 8, 9, 1847—EmMons,
Amer. geology, vol. 1, pt. 2, p. 190, pl. 10, figs. 8, 8c, 9, 1855.

628 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Triplesia ? ambigua Haut, 12th Rep. New York State Cab. Nat. Hist., p. 65, 1859.
Camarella ambigua Mitier, Amer. Paleozoic fossils, p. 107, 1877.

This species has long been difficult to place. The closely spaced and fairly
long dental plates of the pedicle valve preclude placing the species in Camerella,
and the lack of the forked cardinal process of the brachial valve excludes it
from Triplesia. The brachial valve shows the same type of hinge plate as that
of Drepanorhyncha, and the plates are attached at the posterior of the notothyrial
cavity, the sutures showing as two short lines on the umbo of the brachial valve.

Types—Figured hypotypes: 111344a,b.

Horizon and locality—Hull formation in New York: At Trenton Falls,
Russia, and Middleville.

DREPANORHYNCHA OTTAWAENSIS (Billings)
Plate 128, E, figures 20-31

Porambonites ? ottawaensis Bittincs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 140,
fig. 117 (adv. sheets, 1862), 1865.—MILLER, North American geology and paleontology,
p. 362, fig. 508, 1880.

Rhynchotrema ottawaensis (Billings) ScaucueErt, U. S. Geol. Surv. Bull. 87, p. 369, 1897.

Orthorhynchula ottawaensis (Billings) ScHuUcHERT and Cooper, Mem. Peabody Mus. Nat.
Hist., vol. 4, pt. 1, p. 42, pl. 16, figs. 6, 9, 13, 1932.

Rhynchotrema ? ottawaensis (Billings) Witson, Geol. Surv. Canada, Bull. 8, p. 121, pl. 11,
figs. 9-11, 1946.

Horizon and locality Rockland formation in Canada: At Paquette Rapids,
Ottawa River, Ontario.

Types.—Lectotype: G.S.C. 1143g; paratypes: G.S.C. 1143?, 1143¢,h; figured
hypotypes: 85338a,b.

Family RHYNCHOTREMATIDAE Cooper, new family

Rhynchonellacea with rudimentary deltidial plates and well-formed dental
plates in the pedicle valve; brachial valve provided with a small cruralium, with
or without a cardinal process, long crural processes. Cruralium without covering
plates as in Camarotoechia.

Genus RHYNCHOTREMA Hall, 1860
Plate 138, A, figures 1-7

Rhynchotrema HAtt, 13th Rep. New York State Cab. Nat. Hist., p. 68, 1860—Wane, Geol.
Soc. Amer. Mem. 42, p. II, 1949.

For many years this genus has been misunderstood. The only species name
used with the genus when Hall first proposed the name was increbescens. Wang
(1949, p. 11) points out that this species thus becomes the type of the genus.
Under the heading Rhynchonella imcrebescens Hall defined the characters of
Rhynchotrema from specimens taken at Iron Mountain, Wis., specimens that
are now assigned to Lepidocyclus capax. In spite of this inconsistency the genus
rests on R. increbescens. Wang finally fixed the type of R. increbescens as the

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 629

specimen figured by Hall (Pal. New York, vol. 1, pl. 33, fig. 13c-d). Through
the kindness of the American Museum of Natural History and Dr. N. D. Newell,
the writer was permitted to examine this specimen.

The type lot of R. increbescens consists of four specimens. Two of them,
figures a,b and c,d, on plate 33, figure 13, are similar and probably were derived
from the same bed. The third specimen, represented by figures e,f, is black in
color, is wider and thicker, and is probably from a different part of the Trenton
limestone. The last specimen is even larger than the third and has a strongly in-
curved beak and considerably swollen brachial valve. It seems quite different
from the others.

The type specimen selected by Wang is small; length 11.1 mm., width
12.2 mm., and thickness 8.2 mm. None of the original shell remains on this
specimen, but Hall (Pal. New York, vol. 1, p. 147, 1847) implies that it was
marked by “flexuous imbricating striae.”” The sulcus is marked by 3 costae, the
fold by 4, and the flanks by 6 or 7. Unfortunately, the fact that the specimen is
essentially a cast of the interior makes it impossible to determine any of the im-
portant beak characters, but it does permit description of some of the interior
details. The pedicle valve had a moderately deep delthyrial cavity defined by
short, delicate dental plates. No trace of the musculature appears on the cast.

The interior of the brachial valve was provided with a median septum reach-
ing to about the middle and supporting a small cruralium. The hinge plate is
divided with the halves somewhat concave but their shape not determinable.
Muscle marks are not determinable. On the filling of the cruralium a short, thin
white line indicates the presence of a small cardinal process. The latter feature
does not appear on the second specimen which is similar to the lectotype.

This type of interior is characteristic of several species of the middle part of
the Trenton. Along with this interior goes an imbricate ornamentation and beak
characters that set Rhynchotrema off from Wang’s genus Lepidocyclus.

The generic characters of RAynchotrema are here defined as follows: triangu-
lar, costate, rostrate shells usually with lamellose ornamentation; pedicle valve
with delthyrium partially closed by narrow, elongate deltidial plates on the sides ;
beak often resorbed by pedicle pressure to form a small, round foramen ; dental
plates short ; teeth thick and stout, with large fossettes.

Muscle field triangular with diductor scars enclosing the adductors; adduc-
tor scar somewhat heart-shaped, large. Brachial interior with divided hinge
plate ; sockets deep ; socket ridge narrow ; hinge plate gently concave, subtriangu-
lar ; crura curved, moderately long; cardinal process slender to thick, often fill-
ing the cruralium; median septum extending to the middle.

RHYNCHOTREMA KENTUCKIENSE Fenton and Fenton
Plate 130, A, figures 1-8

Rhynchotrema kentuckiense FENTON and Fenton, Proc. Iowa Acad. Sci. for 1922, vol. 209,
p. 67, pl. 1, figs. 4, 5; 18-22, 1924.

630 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Rhynchotrema inaequivalvis Castelnau, WINCHELL and SCHUCHERT, Geol. Minnesota, vol. 3,
pl. 34, figs. 24, 25, 1895.

Types.—Figured hypotypes: 11721 Ia-c.

Horizon and locality—Trenton formation in Kentucky: Danville, Boyle
County; Burgin, Mercer County; Paris, Bourbon County; and Curdsville, Da-
viess County.

RHYNCHOTREMA WISCONSINENSE Fenton and Fenton
Plate 128, H, figures 40-48; plate 138, G, figures 43-45

Rhynchotrema wisconsinense FENTON and FENTON, Proc. Iowa Acad. Sci. for 1922, vol. 209,
p. 71, pl. 1, figs. 6-8, 1924.

Rhynchotrema inaequivalvis Castelnau (part), WINCHELL and ScHucHERT, Geol. Minnesota,
vol. 3, pl. 34, figs. 13, 14, 1895.

Types.—Figured hypotypes: 24843a,b, 1172I0a.
Horizon and locality—Decorah formation (Ion member) in Minnesota and
Wisconsin.

Genus ROSTRICELLULA Ulrich and Cooper, 1942

Rostricellula UtricuH and Cooper, Journ. Paleont., vol. 16, No. 5, p. 625, 1942.

Shell rhynchonelliform, generally subtriangular to subpentagonal in outline,
more rarely transversely elliptical, Anterior commissure uniplicate. Pedicle
valve with pointed and generally incurved beak ; delthyrium open or partially re-
stricted by rudimentary deltidial plates. Interarea narrow, almost obsolete.
Pedicle interior with strong dental plates separated from the sides of the valve
by narrow umbonal cavities. Teeth small, curved. Delthyrial cavity deep, oc-
cupied wholly by the scar of the pedicle attachment; muscle field situated an-
terior to the delthyrial cavity, like Rhynchotrema in pattern.

Brachial interior with divided hinge plate united to median septum by short
supporting plates that form a small chamber or cruralium beneath the beak.
Brachial processes long and slender, curved. Median septum strong, elevated,
reaching to middle of valve or beyond. Adductor impressions located on each
side of the septum in the posterior half of the shell. Cardinal process absent.

Genotype—Rostricellula rostrata Ulrich and Cooper, new species. Journ.
Paleont., vol. 16, No. 5, p. 626, pl. go, figs. 24, 28, 29, 32, 37, 1942.

Discussion—This genus differs from Rhynchotrema by absence of a cardinal
process in the brachial valve and nonimbricate ornamentation.

ROSTRICELLULA ACUTIPLICATA Cooper, new species
Plate 133, F, figures 36-41; plate 138, D, figures 25-38

Shell of about medium size for the genus, wider than long with a somewhat
rectangular outline in the old adult but triangular in young adults. Apical angle
about 105°. Sides rounded; anterior margin truncated. Widest slightly an-
terior to the middle. Fold marked by 3 to 5 costae, the sulcus by 2 to 4, and the
flanks by 7 to 9. Surface finely filate and papillose.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 631

Pedicle valve with nearly flat lateral profile in which the umbonal region is
slightly inflated; anterior profile very gently convex. Sulcus originating 4 to
6 mm. anterior to the beak. Sulcus deep at the front; tongue long and narrow.
Flanks flattened and gently sloping to the margins.

Brachial valve fairly evenly convex in lateral profile but the convexity gentle
and most marked on the fold; anterior profile moderately strongly arched. Um-
bonal region swollen but medially sulcate for a short distance; fold narrow and
high, especially at the front end. Costation of fold variable, costae often appear-
ing on sides of fold. Flanks well rounded and steeply sloping to the margins.

Measurements in mm.—

Brachial
Length length Width Thickness
SEA AE UNO ate as wk a arta. ute Me 13.4 12.2 16.0 9.0
Patdtype MUlT72E2D) aos «care es. < 10.7 9.5 13.6 ra
¥ ye 13.5 12.2 17.0 15.2
ligated) raise. eels ILS 10.4 13.0 6.9

Types.—Holotype: 117212a; figured paratypes: 117212b,d, 117213a,b; un-
figured paratype: 1172I2c.

Horizon and locality——Prosser formation (Zygospira bed) in Minnesota:
At St. Anthony’s Hill, St. Paul; Kenyon, Goodhue County; Cannon Falls,
Goodhue County ; and Warsaw, Rice County.

Discussion.—This species may be recognized by its fairly narrow and fairly
strongly elevated fold, erect beak, and depressed flanks of the brachial valve. This
combination of features is quite unlike those of any other species described herein.
The species somewhat resembles R. pulchra, but that species has a wider and
lower fold and the flanks are not depressed.

ROSTRICELLULA AINSLIEI (N. H. Winchell)
Plate 135, A, figures 1-7; plate 138, E, figure 39
Rhynchonella ainsliei N. H. W1ncHELL, 14th Ann. Rep. Geol. Nat. Hist. Surv. Minnesota,
p. 315, pl. 2, figs. 5, 6, 1886.
Rhynchotrema ainsliei (Winchell) WINCHELL and ScHucHERT, Geol. Minnesota, vol. 3, p. 459,
pl. 34, figs. 1-8, 1895.

A specimen of the brachial valve shows the typical cardinalia of Rostricellula
having very long brachial processes and no cardinal process. The exterior is
marked by fine, crowded, concentric lines of fine pustules.

This species is characterized by its transverse form, evenness of its costae, and
the well-rounded lateral margins. In these respects it differs from other described
species except R. rotunda. From that species it differs in its larger size and
proportions.

Measurements in mm.—Hypotype (24866a), length 13.5, brachial length 12.5,
width 18.0, thickness 10.3.

Types.—Figured hypotypes: 24866a, 48943a.

Horizon and locality—Decorah formation (Spechts Ferry member—Sticto-
porella bed), Minneapolis, west St. Paul, Minnesota. Decorah formation, Chat-
field, Fillmore County; Fountain, Fillmore County; Elmira, Olmstead County.

632 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ROSTRICELLULA ? ANGULATA Cooper, new species
Plate 134, D, figures 33-46

Slightly wider than long, triangular in outline, apical angle slightly less than
go°. Posterolateral margins straight ; anterolateral extremities narrowly rounded ;
anterior margin broadly rounded. Costate, 3 costae on the fold, 2 in the sulcus,
and 6 to 8 on the flanks.

Pedicle valve gently convex in lateral profile, broadly and gently concave in
anterior profile; sulcus originating at about the middle, deepening rapidly.
Tongue moderately long. Anterolateral extremities prominently elevated above
the sulcus. Flanks flattened but with steep slopes.

Brachial valve deeper than the pedicle valve and with low convexity in lateral
view, most convex in the umbonal region but flattened anteriorly. Anterior pro-
file broadly and gently convex. Umbo sulcate; fold originating about 4 mm. an-
terior to the beak; fold flattened in both profiles, elevated strongly only at the
anterior end. Flanks gently rounded and with moderate slopes.

Measurements in mm.—

Brachial
Length length Width Thickness
PLGIGEWDE secre ote ce pee 12.7 12.0 14.5 7.1
Paratype ©. GCIA72EAD) i. eves mee e's 14.0 13.0 14.2 8.6
* (TIZSTAC) . ese cass oh 12.5 11.2 12.4 8.0

Types.—Holotype: 117214a; figured paratype: 117214b; unfigured paratype:
I17214c.

Horizon and locality—Lower part of dark gray shale in Eureka group, in
Nevada: On the north-facing nose of hill 8167 on Martins Ridge, Monitor
Range, Roberts Mountains (1°) Quadrangle.

Discussion.—This species is characterized by distant, strong, angular costae
and by the presence of only 2 costae in the sulcus. This species differs from
R. truncata, the only other one like it, in having only 2 costae in the sulcus, in
having 5 or 6 costae on the flanks rather than 4, and in having a narrower apical
angle and a narrower fold.

ROSTRICELLULA BASALARIS Cooper, new species
Plate 132, E, figures 21-29; plate 132, F, figures 30-37; plate 137,C, figures 20-26;
plate 137, D, figures 27-33; plate 137, F, figures 37-46

Rostricellula pristina Cooper and Coorer (not Raymond), Bull. Geol. Soc. Amer., vol. 57,
p. 112, pl. 2, figs. 16, 17, 1946.

Shell of about medium size, triangular in outline, length and width about equal ;
apical angle slightly less than 90°. Fold marked by 3 or 4 costae, the sulcus by
2 or 3, and the flanks by 5 or 6.

Pedicle valve slightly less deep than the brachial valve, gently convex in lateral
and anterior profiles ; sulcus originating 2 to 3 mm. anterior to the beak, deepen-
ing anteriorly and occupying about half the width at the front, tongue moder-
ately long. Costae bounding sulcus strongly elevated at anterior end; flanks
flattened and moderately steep.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 633

Measurements in mm.—

Brachial
Length length Width Thickness
TERNS ial sa ibiciare! cyacte + ofeiS ae sialaueid 8.8 8.1 0.3 5.4
Paratype: Glib SS0R) cc ese cals 8.2 7.4 8.7 6.6
< BR SCC) 2) hea ee Re eR 0.4 8.5 85 5.9

Types——Holotype: 111520b; figured paratypes: 111458a,b, 1115202,
I11524a-c, 111793a-c, 118036; unfigured paratypes: 111520c,d.

Horizon and locality——Lower Lenoir formation in Tennessee: East of U. S.
Highway 11 about 4 mile south of the hosiery mill in Lenoir City, Lenoir City
(T.V.A. 130-SE) Quadrangle; south bank Southern RR., 14 miles southwest of
Philadelphia, Philadelphia (T.V.A. 130-NW) Quadrangle; 3 miles northeast of
Athens, Athens (T.V.A. 125-NE) Quadrangle; just above the Knox in the cal-
carenites behind the Friends Church, Friendsville, Concord (T.V.A. 138-SW)
Quadrangle ; 50 feet above the Mosheim formation at Marble Bluff, 8 miles west-
northwest of Loudon, Loudon (30’) Quadrangle.

Mosheim formation in Tennessee: 3 mile east of the railroad station just east
of Morristown, Morristown (T.V.A. 163-NE) Quadrangle.

Tumbez formation (part) in Virginia: On Virginia Highway 80, 0.8 mile
north of Geisler Mill, Glade Spring (T.V.A. 212-SE) Quadrangle; in Moccasin
Creek along Virginia Highway 679, # mile south of Tumbez, Moll Creek (T.V.A.
196-SE) Quadrangle; Staunton Lime Quarry, 4 to 3 mile north of Virginia
Highway 250, 2 miles east of Staunton, Staunton (15’) Quadrangle.

Mosheim formation in Alabama: 4 to 4 mile southwest of Newhope Church,
Vandiver (15’) Quadrangle.

Lenoir formation in Alabama: 2 to 3 miles south of Pelham, Bessemer Iron
District (15’) Quadrangle.

Row Park formation in Maryland: On the Duffy Farm, 0.6 miles west of
Hicksville and 0.8 mile south-southwest of Fairview, Williamsport (15’) Quad-
rangle.

Discussion.—For some years this species has been referred to R. pristina Ray-
mond, but it is a quite different species. Rostricellula basalaris occurs in many
places at the base of the Lenoir limestone. It is a lover of calcarenites and some-
what silty limestone. The species is characterized by a distinctly triangular out-
line, a small apical angle, the midwidth anterior to the middle, and a variable
number of costae in the sulcus. The New York Chazyan species is more rounded
laterally and with the maximum midwidth at about the middle. Furthermore,
its apical angle is greater than that of the Southern Appalachians species.

Rostricellula basalaris shows considerable variability from place to place, some
of it due to preservation. Specimens from the Mosheim limestone in Alabama
are often somewhat distorted, as are specimens from Staunton, Va. The distor-
tion may somewhat thicken the shells if the pressure has been directed parallel to
the long axis.

634 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ROSTRICELLULA COLEI Cooper, new species
Plate 138, C, figures 10-24

Shell large for the genus, wider than long with the greatest width at or near
the middle; sides rounded; anterior margin gently convex. Apical angle 105°.
Sulcus marked by 3 to 5 costae, fold by 4 to 6, and the flanks by g to Io.

Pedicle valve moderately convex in lateral profile with the most curvature at
the umbo; anterior profile gently concave in the median region. Sulcus originat-
ing about 7 mm. anterior to the beak. Sulcus narrow and moderately deep, form-
ing somewhat less than half the width. Tongue moderately long and narrow,
somewhat pointed. Flanks flattened, moderately steep.

Brachial valve deeper than the pedicle valve, fairly strongly convex in lateral
profile ; anterior profile varying from moderately to strongly arched. Fold origi-
nating just posterior to the middle, low posteriorly but fairly strongly elevated
anteriorly ; fold generally narrow and composed of a varying number of costae;
median costae of fold often more prominent than lateral ones which may be
located on sides of fold. Flanks inflated and rounded, steep.

Measurements in mm.—
Brachial

Length length Width Thickness
Flolotype urns eae. Gide ete 14.4 12.7 15.9 12.6
Paratype - i( TE72IOA) «50 tya'nd ey 13.6 12.3 16.0 10.0
CTEZATODS soe se alias 15.0 13.8 16.4 11.7
os CUE 7 ZEON). cl oc hale 16.2 14.4 17.9 13.5
s (iE7arGeE) 14). 7.94 16.7 15.1 18.8 15.1
‘ (1EG2EGE) ed cece efit 14.0 Tay 15.0 117,

Types.—Holotype: 117216d; figured paratypes: 117216a,e; unfigured para-
types: 117216b,c,f.

Horizon and locality—Decorah formation (upper part of Ion member) in
Goodhue County, Minn.: From a road cut on the county road 1.1 miles east of
U. S. Highway 52 in the south edge of Cannon Falls; Kenyon. On U. S. High-
way 52, I mile south of Fountain, Fillmore County.

Same formation in Iowa: West of Decorah, Winneshiek County.

Discussion.—Rostricellula colei can be recognized by its large size and swollen
valves. It thus contrasts strongly with Rhynchotrema wisconsinense with which
it occurs. It is further distinguished by a fairly narrow and moderately well ele-
vated fold for such a large shell. It resembles R. minnesotensis in its robust form
but has a narrow fold and more tumid valves besides being a much larger species.

ROSTRICELLULA COMPRESSA Cooper, new species
Plate 133, B, figure 12; plate 134, A, figures 1-18

Shell of about medium size for the genus, triangular in outline with the great-
est width located near the anterior margin. Beak acute, sides nearly straight to
the anterolateral extremities where they are narrowly rounded; anterior margin
abruptly truncated. Costae numbering 15 to 17, 3 or 4 on the fold, 2 on the
flanks and 4 or 5 on the flattened slope between the flanks and the margins; 2

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 635

or 3 costae occurring in the sulcus. Fine ornamentation consisting of irregular
concentric fila.

Pedicle valve very gently convex in lateral profile with the greatest convexity
between the beak and the middle. Umbonal region and posterior third gently
convex ; sulcus originating 7 to 8 mm. anterior to the beak, widening and deep-
ening rapidly to occupy slightly more than half the valve width. Tongue long,
truncated anteriorly, and in old shells somewhat flattened to form a broad base.
Flanks narrowly rounded with strongly pointed anterolateral extremities. Slope
to margins nearly flat and nearly vertical to the commissure, and marked by 4
or 5 obscure costae. Beak incurved; delthyrium open.

Brachial valve gently convex in lateral profile and with the greatest convexity
located at about the middle; anterior profile with a flattened top and nearly verti-
cal sides. Fold originating at 4 to 5 mm. from the beak, scarcely perceptible near
the middle of the valve and becoming more elevated anteriorly but never strongly
set off from the body of the valve. Two median costae of sulcus often slightly
depressed below the bounding costae. Flanks narrowly rounded with the antero-
lateral extremities elongated in the direction of the pedicle valve and, with the
fold, forming a deep reentrant that accommodates the tongue of the pedicle valve.
Sides steep and nearly vertical to the commissure. Umbo sulcate.

Interior: Teeth small, dental plates well developed but short and confined to
the sides of the valve, forming narrow slitlike umbonal cavities. Delthyrial cavity
occupied by pedicle callist; muscle field located anterior to callist and dental
plates ; adductor scar small, oval, located in the posteromedian position next to
the callist. Diductor scars large, flabellate, and surrounding other scars. Acces-
sory diductors located in front of and on each side of the adductor scar.

Hinge plate divided, the halves supported by short plates attached to their
under side and to the median septum to form a narrow chamber ; outer side of
hinge plates attached to side of valve by well-defined fulcral plates. Socket plates
stout ; outer hinge plates triangular, gently concave, giving off long slender crura
from their inner side.

Measurements in mm.—

Brachial
Length length Width Thickness
Hightech ws ottade oid Wo. awake 12.7 11.4 II.9 8.6
Paratype (GILTAGS ) s <:d.s.+ ee aan 12.1 10.9 11.0 9.9
= WERE ADEE ) cs tot 5. -sithisn gece 6.9 5.1 5.9 3.5
i GINEADEA sac sans ans cise 13.7 i239 13.3 10.0

Types.—Holotype: 111481a; figured paratypes: 111462a-c, 111468, 111481c;
unfigured paratypes: 111480a,b, 111481b,d.

Horizon and locality —Lebanon formation in Rutherford County, Tenn.: On
U. S. Highway 41, ? mile south of Knox Branch, about g miles southeast of
Murfreesboro; 3 miles east and 3 miles northeast of Murfreesboro; cut and
quarry on U. S. Highway 41, 12 miles southeast of Murfreesboro; Mount
Olivet, 10 miles southeast of Murfreesboro on U. S. Highway 41; U. S. High-
way 241, 14 miles (airline) southwest of Christiana. In Bedford County, Tenn.:

636 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Tennessee Highway 16, 3.6 and 5.1 miles northwest of Shelbyville; 3 miles
southwest of Woodbury. In Sequatchie Valley, Bledsoe County, Tenn.: Cedar
Ridge, 1 mile southeast of Litton, Sequatchie Valley, Pikeville Special (15’)
Quadrangle. In Smith County, Tenn.: At the east end of the bridge on U. S.
Highway 70N over Round Lick Creek at Rome. In Maury County, Tenn.: At
Columbia.

Camp Nelson formation in Kentucky: At 140 to 150 feet, High Bridge,
Harrodsburg (30’) Quadrangle.

ROSTRICELLULA COSTATA Cooper, new species
Plate 130, B, figures 9-17
Camarotoechia plena ? Butts, Alabama Geol. Surv., Special Rep. 14, pl. 22, figs. 4, 5, 1926.

Shell small for the genus, triangular to subpentagonal in outline; valves sub-
equal in depth; beak slightly obtuse; sides nearly straight to slightly rounded ;
anterolateral extremities narrowly rounded and forming location of greatest
width ; front margin truncated. Surface costate, 3 costae generally occupying the
sulcus, 4 on the fold, and 6 on the flanks.

Pedicle valve moderately convex in lateral profile with the greatest convexity
located in the umbonal region ; posterior half very gently convex ; sulcus originat-
ing about 3 mm. anterior to the beak, broad and shallow, occupying about two-
thirds the width at the front ; tongue short, narrowly rounded toward the brachial
valve, serrate but square in front. Sulcus bounded on each side by a strongly
elevated angular costa higher than the costae of the sulcus and the flanks, which
are narrow and steep-sided.

Brachial valve moderately convex in lateral profile with the greatest curva-
ture located in the anterior part. Posterior half sulcate with the sulcus broad
and shallow and bounded by narrowly rounded flanks. At about the middle,
24 mm. from the beak of the brachial valve a fold develops out of the posterior
sulcus in the form of 2 depressed costae flanked by a costa strongly elevated
above those of the fold and the flanks on each side. Slopes to margins nearly
vertical and flat-sided ; flanks bounding sulcus narrowly rounded.

Interior: A single specimen shows a well-developed muscle field in the pedicle
valve located anterior to the short dental plates. The field is trapezoidal in out-
line with a straight front margin. Individual scars not distinguishable.

Measurements in mm.—

Brachial
Length length Width Thickness
I GIOEV IG! 2s cicoeipinta ny ae pinto cin es Mat 5.2 4.9 5.6 4.2
Paratype’ (71486) -253.0) Jghee ta 6.0 5.5 5.9 5.0
a CYUTACODN tre nate tis eee es 6.0+ 5.9 6.6 4.0

Types.—Holotype: 111460a; unfigured paratype: 111460b; measured para-
type: 71486.

Horizon and locality—Lenoir formation in Alabama: 2 miles west-southwest
of Pratt Ferry, Blocton (15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 637

Discussion.—This is a small species distinguished by the pronounced sulcate
brachial umbo and the depression of the median 2 costae below the level of the
outer 2 in the fold. The species may be related to R. pristina but is generally
smaller and proportionately more convex. It differs from R. orientalis, which is
a small shell, in the nature of the folding and the more compact outline and profile.

ROSTRICELLULA CUNEATA Cooper, new species
Plate 124, H, figures 44, 45

Shell small for the genus, cuneate, longer than wide; beak acute; sides nearly
straight, divergent; anterior truncated. Surface marked by 11 narrowly rounded
and elevated costae.

Pedicle valve gently convex in lateral profile except for the front which is
narrowly rounded; anterior profile moderately broadly rounded. Umbonal region
narrowly rounded ; median region somewhat carinated by the prominent median
costa. Median 3 or 5 costae elevated slightly in the anterior half to form a low
fold; sides rounded and steep. Dental plates long and slightly curved.

Brachial valve gently convex in lateral profile except for the front marginal
region which is narrowly curved toward the pedicle valve; anterior profile flat-
tened to concave medianly but with narrowly rounded sides. Sulcus originating
at the umbo and extending to the anterior margin. Median 2 to 4 costae bound-
ing median sulcus depressed below the flanks to form a broad sulcate zone; flanks
narrowly rounded and with nearly vertical sides, marked by 3 to 4 costae.
Median septum long.

Measurements in mmn.—

Brachial Widest
Length length Midwidth part Thickness
ERE Ose nisi aici n Si 4.0 a7 3.0 3.4 25
Paratype (117218b)..... SG) Br 2.5 3.1 1.8
a (TPVA18E yD: 4.8 rp 3 4.0 1.5

Types.—Holotype: 117218a; unfigured paratypes: 117218b-d.

Horizon and locality —Bromide formation (Mountain Lake member) in Okla-
homa: West side U. S. Highway 77, sec. 25, T. 2 S., R. 1 E., 2 to 3 miles north
of Springer, Carter County.

Discussion.—This species strongly resembles members of the genera Spheno-
treta and Dorytreta, but the presence of the thick median septum in the brachial
valve indicates affinities with Rostricellula. This species suggests young speci-
mens of R. costata, but in that species the brachial valve is less sulcate than
R. cuneata.

ROSTRICELLULA CUNEIFORMIS (Fenton and Fenton)
Plate 136, A, figures 1-22
Rhynchotrema cuneiformis FENTON and Fenton, Proc. Iowa Acad. Sci. for 1922, vol. 20,
p. 72, pl. 1, figs. 12-14, 1924.

Silicified specimens of this species show the interior to perfection. In the
pedicle valve the deep delthyrial cavity is occupied by a thickened pedicle callist

638 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

and the muscle area is located in front of it. The adductor field is deeply im-
pressed. Inside the brachial valve the median septum is high and strong and
supports a small cruralium, but a cardinal process is absent as usual for the
genus. The brachial processes are long and curved.

Types—Figured hypotypes: 11148 4a,d,e,g,o-r,t,u.

Horizon and locality—Barnhart formation (or Macy) in Missouri: Along
the old road 1 mile northwest of the Chicago Summer School Camp, NW4SW+4
sec. 32, T. 37 N., R.g E., Weingarten (15’) Quadrangle; on the Fredericktown
road, 5 miles southwest of Ste. Genevieve, Weingarten (15’) Quadrangle; 0.2
mile south of Koch Valley School on U. S. Highway 67, Kimmswick (15’)
Quadrangle.

ROSTRICELLULA DECORAHENSIS (Fenton and Fenton)

Rhynchotrema decorahense FENTON and Fenton, Proc. Iowa Acad. Sci. for 1922, vol. 20,
p. 72, pl. 1, figs. 9-11, 1924.

Types.—Univ. Chicago.
Horizon and locality—Decorah formation in Iowa.

ROSTRICELLULA ELLIPTICA Cooper, new species
Plate 132, A, figures I-5

Shells somewhat below medium size, elliptical in outline, sides narrowly
rounded; the midwidth forming the widest part; apical angle about 100°; an-
terior margin nearly straight. Sulcus with 4 or 5 costae, fold with 5 or 6 costae,
and the flanks marked by about 8 costae. Costae of fold and sulcus more widely
spaced than those of the flanks.

Pedicle valve moderately convex in lateral profile and with the maximum
curvature just anterior to the umbo; anterior profile fairly strongly convex; sul-
cus originating at about the middle; umbo somewhat swollen. Sulcus moderately
deep anteriorly, its width equal to about half the valve width. Flanks moderately
swollen and steep. Beak short and strongly incurved.

Brachial valve about equal to the pedicle valve in depth, moderately strongly
convex, more so than the pedicle valve in lateral profile; anterior profile strongly
convex and with steep sides. Fold originating near the middle, low throughout
its extent. Flanks strongly swollen.

Measurements in mm.—

Brachial
Length length Width Thickness
GRIMer iS Ao ts the i eat Sie 5.2 4.8 6.8 3.5
Paratype’ (0072Z07D) cect te cnt os 7.0 6.1 7.6 4.9
re (TT72170):. RK REMIOR ? ? 10.0 ?
- CIT7297G) a ore aa eer ai 5.6 5.0 6.7 3.2

Types.—Holotype: 1172174; figured paratypes: 117217b-d; unfigured para-
type: 117217e.
Horizon and locality—New Market formation in Virginia: From a quarry

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 639

4 mile west of U. S. Highway 11, on the north bank of Middle River, Staunton
(15’) Quadrangle.

Discussion.—This is a small species, represented by specimens of poor preser-
vation. The specimens indicate a species so at variance with F. basalaris that a
different specific name was thought to be warranted. The species is characterized
by soft, rounded outlines and elliptical form with numerous costae marking the
fold, sulcus, and flanks. It resembles R. multicostata but differs in size, less
elongate outline, and somewhat wider fold. Rostricellula basalaris is more tri-
angular and has more distant and coarser costae and is not likely to be confused
with R, elliptica.

ROSTRICELLULA MAJOR (Raymond)
Plate 130, H, figures 38-42

Camarotoechia major RaymMonp, Amer. Journ. Sci., ser. 4, vol. 20, p. 369, 1905; Ann.
Carnegie Mus., vol. 7, No. 2, p. 226, pl. 34, figs. 11-14, I9QII.

Type.—Holotype: Carnegie Mus. 2171.

Horizon and locality—vValcour formation in New York: At Cystid Point,
Valcour Island, Lake Champlain, Plattsburg (15’) Quadrangle.

Same formation in Vermont: From a small peninsula off the west shore of
Providence Island, Plattsburg (15’) Quadrangle.

ROSTRICELLULA MINNESOTENSIS (Sardeson)
Plate 131, A, figures 1-7; plate 139, A, figures I-11

Rhynchonella minnesotensis SARDESON, Minnesota Acad. Nat. Sci., Bull. 3, p. 333, pl. 4,
figs. 21-23, 1892.

This species is characterized by fairly large size and solid, robust form. It has
an apical angle of slightly more than 90°, rounded sides, and a truncated front.
The fold has 4 costae, the sulcus 3 costae, and the flanks are marked by 6 or 7
costae.

The valves are of subequal depth and fairly deep; the profiles are moderately
convex. The brachial umbo is sulcate, and the 2 median costae do not equal the
elevation of the lateral costae until about the middle of the valve. The tongue
of the pedicle valve is fairly long, but the fold of the brachial valve is low and
flattened in profile.

Measurements in mm.—
Brachial

Length length Width Thickness
Hypotype (1i7artoa) wie. Jat 16.3 11.6 15.0 11.2
i CLIG2LOD You, he Jose Meas 12.0 10.6 12.9 8.3

Types.—Figured hypotypes : 117219a,b, 118035.

Horizon and locality.—Platteville formation (McGregor member) in Wiscon-
sin: On Highway 81, 1 mile northwest of Ellenboro, Lancaster (30’) Quad-
rangle ; Janesville and Beloit, Rock County ; Mineral Port, Mineral Point (30’)
Quadrangle; Dodgeville, Iowa County.

640 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Same formation in Minnesota: At Fountain, Fillmore County.

Same formation in Illinois: 14 miles northeast of Dixon, Lee County. De-
corah formation (Spechts Ferry member) in Minnesota: On the road $ mile
east of U. S. Highway 52 in the south edge of Cannon Falls, Goodhue County.

Discussion—Rostricellula minnesotensis is best identified by its rotund and
robust form, combined with swollen flanks and low, wide fold. The species sug-
gests R. colei but differs in having a wider and lower fold. It is similar to
R. pulchra but differs in its more robust and rotund form, more strongly costate
flanks, and less strongly costate sulcus.

ROSTRICELLULA ? MINUTA Cooper, new species
Plate 137, A, figures 1-6

Shell small for the genus, elliptical in outline with the greatest width at about
the middle. Sides narrowly rounded; anterior margin broadly rounded. Fold
marked by 2 strong, angular costae; sulcus containing a single costa, and flanks
marked by 7 or 8 costae.

Pedicle valve about equal in depth to the brachial valve, gently convex in lat-
eral profile and with the greatest convexity at about the middle. Anterior profile
moderately convex. Beak strongly incurved; umbo narrowly swollen. Sulcus
originating about 14 mm. anterior to the beak, deep and occupying about half
the width; costae bounding sulcus strongly elevated and forming a sort of fold
bounding the sulcus. Flanks concave and with a steep slope to the margins.
Tongue moderately long.

Brachial valve nearly flat in the median region when seen in lateral profile but
with the umbonal and anterior regions narrowly convex; anterior profile gently
convex but with the fold much elevated. Fold narrow and elevated particularly
at the front end. Flanks moderately swollen.

Measurements in mm.—Holotype, length 5.3, brachial length 4.9, width 6.3,
thickness 3.6.

Types.—Holotype: 1172204; figured paratype: 117220b.

Horizon and locality—Hermitage formation in Tennessee: From 0.7 to 1.25
miles south-southeast of Woodbury, Woodbury (15’) Quadrangle.

Discussion.—This species is characterized by its small size, the exceptionally
deep sulcus, and high narrow fold. It is further characterized by having only a
single costa in the sulcus. The exterior aspect of the species is unlike most known
Rostricellula, but a cross section of the brachial beak indicates a structure nor-
mal for Rostricellula. The pedicle valve possesses moderately long dental plates
and foraminal characters like Rostricellula. The interior features thus indicate
relationship to Rostricellula. The exterior surface, however, deviates from Ros-
tricellula as far as can be observed in lacking fine wavy lines or granules. The
combination of specific characters in this species is unlike any others described
herein.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 641

ROSTRICELLULA MISSOURIENSIS (Fenton and Fenton)
Plate 135, B, figures 8-10

Rhynchotrema missouriense FENTON and Fenton, Proc. Iowa Acad. Sci. for 1922, vol. 20,
p. 73, pl. 2, figs. 22-26, 1924.

Figured specimen.—111488.

Horizon and locality—Barnhart (or Macy) formation in Weingarten (15’)
Quadrangle, Missouri: 24 miles west of Ste. Genevieve; 14 miles north of Chi-
cago Summer School Camp.

ROSTRICELLULA MULTICOSTATA Cooper, new species
Plate 139, D, figures 37-53

Shell of about medium size for the genus, slightly wider than long; apical
angle about 100°; sides narrowly rounded; anterior margin gently and broadly
rounded. Costate, 4 to 8 costae in the sulcus, 5 to 9 on the fold, and 11 on the
flanks.

Pedicle valve gently convex in lateral profile and with the greatest convexity
at the umbo; anterior profile broadly and gently convex; sulcus originating 2 to
3 mm. anterior to the beak; sulcus broad and shallow throughout ; tongue short,
broadly rounded. Umbo strongly swollen; beak strongly curved and overhang-
ing the brachial umbo. Flanks narrow, gently convex and with steep slopes.

Brachial valve fairly strongly convex in lateral profile and with the maximum
convexity at the middle; anterior profile strongly and broadly convex; fold origi-
nating at or near the middle, low throughout its extent; umbonal and median
regions inflated ; flanks swollen and with steep slopes.

Measurements in mm.—

Brachial
Length length Width Thickness
TVG 5 ML es er 11.3 10.0 12.4 7.6
Pasaty pe GIIZAAED) it on, dbs ceil ht 0.7 8.6 10.7 Vf
- (Gat 75 ee ee 10.0 8.7 10.2 Ge
USAT was S yigsls sare oa 10.1 9.0 9.6 6.7
3 CEN O2IE) Soe tk oe oe 9.2 8.0 10.2 6.6
e CE QBTEy CANIS VN GA 8.7 7.7 9.6 6.6
‘ (aigoone io: Sees. ova Be 6.8 6.2 7.4 4.8
# GRIF A2TE Viesie’ surctepon S8e 6.1 5.5 6.8 4.1

Types.—Holotype: 1172214; figured paratypes: 11722Ic,e; unfigured para-
types : 117221b,d,f-i.

Horizon and locahty.—Ellett formation, calcarenite 10 feet above the Knox
in Virginia: Slope on west side Virginia County Highway 615, 1 mile south of
Ellett, Blacksburg (15’) Quadrangle.

Discussion.—This species is suggestive of R. plena (Hall) but is uniformly
smaller in size than that species and is a more rotund form. It differs from other
species seen at the base of the Lenoir in its larger size and more numerous costae.

642 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ROSTRICELLULA NUCLEOLATA Cooper, new species
Plate 135, D, figures 16-25

Shell small for the genus, somewhat globular, slightly wider than long. Pos-
terolateral margins short and straight, sides moderately rounded; anterior mar-
gin broadly rounded. Apical angle slightly less than 100°. Costae elevated and
narrowly rounded, numbering 4 on the fold, 3 in the sulcus, and 4 on the flanks.

Pedicle valve gently convex in lateral profile and nearly flat in anterior pro-
file; umbonal region convex and somewhat swollen; sulcus broad and shallow,
originating 5 mm. anterior to the beak which is strongly incurved. Tongue short,
not strongly geniculated. Flanks narrowly rounded and steep.

Brachial valve slightly deeper than the pedicle valve, evenly and gently convex
in lateral profile, broadly and flatly convex in anterior profile but with precipitous
sides. Umbonal region gently sulcate ; fold low, slightly elevated above the flanks
at the anterior end. Flanks narrowly rounded and steep-sided.

Measurements in mm.—Holotype, length 9.3, brachial length 8.4, width 10.0,
thickness 7.0.

Types.—Holotype: 48984a; unfigured paratypes: 48984 (unlettered).

Horizon and locality.—Platteville formation (lower buff = Pecatonica member)
in Minnesota: At Minneapolis.

Discussion.—Small size and rotund form characterize this species. Its nearest
relative is R. minnesotensis from which it differs in size, rotundity, and a wider
fold and sulcus.

ROSTRICELLULA ORIENTALIS (Billings)
Plate 129, G, figures 26-32; plate 135, C, figures 11-15; plate 137, 1, figures 61-65

Rhynchonella orientalis B1Lttncs, Canadian Nat., vol. 4, p. 443, fig. 21, 1859.—Locan, Geol.
Canada, p. 126, fig. 57, 1863.

Camarotoechia orientalis (Billings) RAymMonp, Ann. Carnegie Mus., vol. 7, No. 2, p. 223,
pl. 33, figs. 32, 33, I91I.—TWENHOFEL and Waitin, Geol. Soc. Amer. Special Pap. 11,
p. 51, pl. 7, figs. 22-24, 1938.

A small shell frequently misidentified. The writer has seen few authentic ex-
amples of this species outside of the Mingan Islands. The specimens from
St. Martin Junction, Quebec, identified as this species by Raymond are herein
referred to a new species, R. raymondi. The one specimen of this species from
Aylmer, Quebec, in Raymond’s lot has the size and ornamentation of R. orien-
talis but is too crushed to make the identification positive. The species is not
reported from New York.

Types.—Figured hypotypes: 111489, 111490a; G.S.C. 2184.

Horizon and locality—Mingan formation, Mingan Islands, St. Lawrence
River, Canada.

ROSTRICELLULA OVATA Cooper, new species
Plate 131, E, figures 33-39; plate 133, E, figures 27-35

Shell of about medium size, triangular in outline with the length and width
nearly equal. Greatest width anterior to the middle; sides long and straight

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 643

forming an apical angle of about 82°. Anterolateral extremities narrowly
rounded; anterior margin gently curved. Sulcus marked by 4 to 5 costae, the
fold by 5 to 6 costae, and the flanks by 5 or 6 costae. Surface crossed by mod-
erately strong fila.

Pedicle valve fairly evenly but gently convex in lateral profile; anterior profile
gently depressed in the median region, precipitous on the sides. Beak narrow,
incurved ; umbo slightly swollen ; sulcus originating about 7 mm. anterior to the
beak; sulcus shallow and broad, occupying about half the width. Sulcus de-
pressed slightly below the flanks at the front; flanks narrow, rounded, and steep.

Brachial valve deeper than the pedicle valve, moderately convex in lateral
profile and with the umbonal region having the greatest curvature; anterior pro-
file moderately arched. Fold broad and low, not strongly elevated at the front,
and its place of origin not clear but near the middle; flanks strongly rounded
and precipitous.

Measurements in mm.—
Brachial

Length length Width Thickness
HiGloty pes... 2A? SVT. - 14.2 12.8 13.8 8.7
Paratype stash besos oS) Bent . <3 14.4 13.1 12.8 8.9

Types.—Holotype: 117222; figured paratype: 111532.

Horizon and locality—Dryden formation (=Wardell part) in Virginia: In
a quarry just east of Virginia State Highway 70, north of Powell River, 1.6
miles south of Jonesville, Ben Hur (T.V.A. 170-NE) Quadrangle.

Same formation in Tennessee: At Mulberry Gap in Powell Mountain, 5 miles
north of Sneedville, Sneedville (T.V.A. 170-SW) Quadrangle.

Hostler formation in Pennsylvania: At the National Lime Quarry, Shrader
Station= Naginey Post Office, Lewistown (15’) Quadrangle.

Ooltewah formation in Tennessee: 34 miles north of Ooltewah, Ooltewah
(T.V.A. 112-SE) Quadrangle.

Discussion.—This species is characterized by having its length and width
nearly equal but with the length often the greater, a low, wide fold, and sulcus
marked by numerous costae. The species is very similar to R. plena of the Val-
cour limestone, New York, but does not attain the large size and robust form of
that species. Rostricellula plena usually has deeper valves, with a more incurved
pedicle beak and more numerous costae on the fold and in the sulcus. Rostricel-
lula ovata differs from R. rostrata in its more elongate form and the fact that the
greatest width is more anterior than that of FR. rostrata. Furthermore, the fold
of the latter species is more pronounced and the costae less numerous and more
distant in R. rostrata.

ROSTRICELLULA PARVA Cooper, new species
Plate 134, C, figures 27-32

Shell small, triangular in outline, slightly wider than long; greatest width at
about the middle; anterior margin nearly straight; apical angle slightly greater

644 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

than a right angle. Fold marked by 7 costae and the sulcus by 6 costae; flanks
marked by 9 costae.

Pedicle valve gently convex in lateral profile, broadly and gently convex in
anterior profile ; sulcus shallow and wide, occupying about half the width; flanks
gently rounded and moderately steep.

Brachial valve gently convex in lateral profile and with the greatest convexity
at about the middle; anterior profile broadly rounded but only moderately con-
vex; fold low, noticeably elevated at the front; flanks rounded and moderately
steep.

Measurements in mm.—Holotype, length 7.8, brachial length 6.9, width 8.3,
thickness 4.5.

Types.—Holotype: 117223a; unfigured paratype: 117223b.

Horizon and locality Bromide formation (Pooleville member) in Oklahoma:
On Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray County.

Discussion.—This species is characterized by its small size, numerous costae
on the fold and sulcus, and length and width nearly equal. The species is sug-
gestive of FR. pristina in size but has more numerous costae. It differs in the
same respects from R. orientalis, R. basalaris, and R. raymondi.

ROSTRICELLULA PLATTINENSIS (Fenton)
Plate 132, H, figures 43-51
Protorhyncha plattinensis Fenton, Amer. Midland Nat., vol. 11, p. 135, pl. 3, figs. 21-24, 1928.

A small variable species originally assigned to Protorhyncha, to which genus
it does not belong. Specimens from the type locality show the characteristic
median septum and rostral chamber without a cardinal process of Rostricellula.
The whole habit of the species is that of the latter genus rather than Protorhyncha
or the new genus Ancistrorhyncha. Specimens of the latter occur with R. plat-
tinensis but could not be confused with it as they are ornamented by fine
costae or costellae and are without a median septum. The serial sections figured
by Fenton (pl. 4, figs. 1-6) do not conform either to Rostricellula or Ancistro-
rhyncha.

Measurements in mm.—Hypotype (111491), length 10.5, brachial length 9.5,
width 11.3, thickness 7.1.

Type.—Figured hypotype: 111491.

Horizon and locality—Plattin group (lower) in Missouri: On the J. Heck
place, 14 miles south-southeast of River Aux Vasses, Weingarten (15’) Quad-
rangle.

Discussion—The narrowly rounded fold of this species is its chief character-
istic. The 2 median costae of the fold are elevated above the 2 lateral ones, thus
producing a narrowly rounded fold when viewed in anterior profile. In this re-
spect it is somewhat like R. acutiplicata, but that species is wider, differently
ornamented, and with different proportions to the valves.

PART, ft CHAZYAN AND RELATED BRACHIOPODS—COOPER 645

ROSTRICELLULA PLENA (Hall)
Plate 120, I, figures 39-53; plate 132, D, figures 19, 20; plate 137, FE, figures 34-36

Aitrypa plena Haut, Pal. New York, vol. 1, p. 21, pl. 4 bis, figs. 7a-c, 1847.
Camarotoechia plena (Hall) Raymonp, Ann. Carnegie Mus., vol. 7, No. 2, p. 221, pl. 33,
figs. 7-18, IQII.
For full synonymy see Bassler, U. S. Nat. Mus. Bull. 92, p. 178, 1915.

Attains a large size and is one of the biggest of the known species of this
genus. Occurs in great abundance in the Valcour formation in the vicinity of
Chazy and on Valcour Island. Raymond has discussed the variation of the
species and concludes that Afrypa altilis and A. plicifera are variations of
A. plena.

The adult is generally subtriangular in outline, with the length and width about
equal; maximum width at or a short distance anterior to the middle. Surface
marked by 17 to 24 costae, 5 to 7 in the sulcus and 1 more on the fold. The
sulcus of the pedicle valve originates about 5 mm. anterior to the beak and usu-
ally occupies from one-half to three-fourths the width at the front; flanks flat-
tened and with moderately steep slopes. Brachial valve strongly convex in both
profiles with more or less prominent fold originating anterior to the sulcate
umbo. Fold gently rounded in profile, moderately elevated above the flanks
anteriorly ; flanks rounded and with steep slopes.

Measurements in mm.—
Brachial

Length length Width Thickness
Figured hypotype (III5IO).......... 17.0 15.5 16.4 11.9
x as (rrrgpyaieiet f Oils 16.8 15.2 17.7 13.6
s Gimrgoga))i: 62 . cee 15.7 13.7 14.8 11.3

Types.—Holotype: A.M.N.H. 530/1; figured hypotypes: 111497a, 111509,
111510, G.S.C. 1040; measured hypotype: 111409.

Horizon and locality—vValcour formation in New York: Abundant in the
vicinity of Chazy, Rouses Point (15’) Quadrangle, and on Valcour Island,
Plattsburg (15’) Quadrangle.

St. Martin formation in Quebec, Canada: At Montreal.

Aylmer formation in Canada: In the Ottawa Valley.

Row Park formation in Pennsylvania: From a cut on Pennsylvania Highway
995, south of Conococheague Creek, 1 mile north of Welsh Run (identification
doubtful), Mercersburg (15’) Quadrangle.

Discussion.—Rostricellula plena is one of the largest and most robust species
of this genus. It is characterized by a low but wide fold and sulcus, both occu-
pied by numerous costae. The brachial valve is much deeper than the pedicle
valve and is strongly swollen and convex. Although this species is one of the
earliest of the genus, its large size and robust form mark it as an advanced type.
The only Appalachian species approaching this one in size is R. tumidula. The
two species, however, are not likely to be confused because R. twmidula is more
strongly costate, has a more shallow sulcus and lower fold, and somewhat less
strongly convex valves.

646 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ROSTRICELLULA PLENA ALTILIS (Hall)
Plate 130, D, figures 20-24
Atrypa altilis Hatt, Pal. New York, vol. 1, p. 23, pl. 4 bis, figs. 9a-d, 1847.

This subspecies in its extreme form can be readily distinguished from FR. plena
by the compressed form and crowding of the costae. The variety seems to grade
into normal forms of the species. Common in places.

Type.—Holotype: A.M.N.H. 532/1.

Horizon and locality—Valcour formation in New York: On the road along
Little Monty Bay, $ mile north of Bocar Point, southeast of Chazy, and at Chazy,
Rouses Point (15’) Quadrangle.

ROSTRICELLULA PLENA PLICIFERA (Hall)
Plate 130, C, figures 18, 19
Atrypa plicifera Hatt, Pal. New York, vol. 1, p. 22, pl. 4 bis, figs. 8a-d, 1847.

This name can be applied to a depressed shell with somewhat more spreading
costae and rounder form than is usual in the species. Hall’s type specimen is
somewhat crushed, and this may be the reason for the characters exhibited. As
all the limestones of the Lake Champlain region have been much deformed, it
is possible that some of the variation of the contained shells is due to deforma-
tion during the squeezing of the limestone. A specimen almost identical with
Hall’s type occurs with specimens that show other deformation.

Type.—Holotype: A.M.N.H. 533.

Horizon and locality.—Valcour formation in New York: On the west side of
New York Highway 22, on Kennon Brook, 4 mile south of East Beekmantown,
Plattsburg (15’) Quadrangle; Chazy, Rouses Point (15’) Quadrangle.

ROSTRICELLULA PRISTINA (Raymond)
Plate 132, B, figures 6-10

Camarotoechia pristina RAyMonp, Amer. Journ. Sci. ser. 4, vol. 20, p. 368, 1905; Ann.
Carnegie Mus., vol. 7, No. 2, p. 225, pl. 24, figs. 1-10, 1905.

Type.—Figured hypotype; A.M.N.H. 25047/2.

Horizon and locality—Crown Point formation in New York: Sloop Bay, Val-
cour Island, Lake Champlain, Plattsburg (15’) Quadrangle.

Discussion.—This species is characterized by its small size and the presence
of 3 costae in the sulcus and 4 on the fold. Preliminary identifications of small
Rostricellulas from the Lenoir of the Southern Appalachians were made with
this species, but closer examination of the specimens and comparison with topo-
types of R. pristina indicate different species. The Lenoir species is now re-
ferred to R. basalaris and other species.

ROSTRICELLULA PULCHRA Cooper, new species
Plate 135, E, figures 26-35

Shell of about medium size, wider than long; greatest width at or near the
middle; apical angle nearly 100°; anterior margin truncated. Sulcus having 3

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 647

or 4 costae, the fold having 4 or 5 costae, and the flanks marked by as many as
10 costae.

Pedicle valve gently convex in lateral profile with the maximum curvature be-
tween the umbo and the middle; anterior profile flattened or concave medially
and with steep lateral slopes. Sulcus originating 5 or 6 mm. anterior to the beak.
Sulcus deepening anteriorly from the middle of the valve, never very deep even
at the anterior end. Tongue moderately long. Flanks flattened and with moder-
ately steep slopes.

Brachial valve of about equal depth to that of the pedicle valve; lateral pro-
file gently convex; anterior profile broadly convex and with precipitous sides.
Umbo gently swollen, narrowly sulcate. Fold originating near the middle of the
valve, not strongly elevated even at the front. Flanks swollen and only slightly
depressed below the fold; lateral slopes steep.

Measurements in mm.—

Brachial
Length length Thickness Width
LOA ee ne 12.0 II.I ite Hy, 8.7
Paratype Wrasse. Meee ert eke 10.8 10.0 11.8 7.6

Types.—Holotype: 117224b; unfigured paratype: 1172244.

Horizon and locality—Decorah formation (Guttenburg member-Rhimidictya
bed) in Minnesota: In the Mississippi River bluffs at St. Paul.

Discussion.—This species has a broad, low fold and sulcus, broad outline with
the midwidth forming the widest part, and a fairly large apical angle. The species
is somewhat intermediate between R. minnesotensis and R. colei. From the
former it differs in having a much less rotund profile and smaller and more
numerous costae; it differs from the latter in being much smaller and having a
wider fold. It appears to be a more robust shell than R. missouriensis and differs
from R. decorahensis in being wider and more numerously costate.

ROSTRICELLULA RAYMONDI Cooper, new species
Plate 130, E, figures 25-34; plate 130, F, figure 35; plate 132, C, figures 11-18
Camarotoechia orientalis RAyMoND (part), Ann. Carnegie Mus., vol. 7, No. 2, p. 223, pl. 35,
figs. 19-22, 24-31 (not 32 and 33), IgII.

Shell of about medium size for the genus, subelliptical to subtriangular in out-
line; beak ranging from a right angle to obtuse; sides narrowly rounded; front
margin subnasute; surface costate, generally 3 costae marking the sulcus (occa-
sionally 4) and 4 the fold (occasionally 5), with the flanks occupied by 6 or 7
costae, the last 3 or 4 obscure.

Pedicle valve gently convex in lateral profile with the most convex part lo-
cated in the posterior half; umbonal region narrowly convex; sulcus originating
about 5 mm. anterior to the beak, deep and occupying more than half the width
at the front; tongue moderately long; flanks flat in profile and with moderate
slopes to the margins. Costae forming margin of sulcus elevated strongly an-
teriorly above the sulcus to form pointed extremities.

Brachial valve about equal to the pedicle valve in depth, gently convex in

648 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

profile with the greatest curvature in the umbonal region; umbo slightly sulcate,
somewhat swollen on the sides; fold low posteriorly but strongly elevated an-
teriorly ; rounded in profile with the median 2 costae standing above the flanking
ones ; anterolateral extremities depressed toward the pedicle valve; flanks mod-
erately convex, posterolateral slopes nearly vertical.

Measurements in mm.—

Length Width Thickness
PRGIGE YO E cca. io he cis AES av ctatoympaisys ess wieiciee 13.6 15.4 9.1
Paratype (Carnegie Mus. 2174)............ 12.2 13.0 8.2

Types.—Holotype: Carnegie Mus. 2176; figured paratypes: Carnegie Mus.
2174, 2175, U.S.N.M. 117225; unfigured paratypes: Carnegie Mus. 2172, 2173,
2177-2179.

Horizon and locality—St. Martin formation in Quebec, Canada: St. Martin
Junction, near Montreal.

Crown Point (or Valcour) formation in New York: On Valcour Island, Lake
Champlain, Plattsburg (15’) Quadrangle.

Discussion —This species differs from FR. orientalis (Billings) in its less cari-
nate fold which is much less elevated anteriorly and has a proportionately shorter
tongue. The anterolateral extremities of R. orientalis are much more narrowly
rounded than those of the shell from St. Martin Junction. Furthermore, R. orien-
talis attains only about half the size of FR. raymondi.

ROSTRICELLULA ROSTRATA Ulrich and Cooper
Plate 131, B, figures 8-16; plate 131, F, figures 40-46; plate 136, B, figures 23-34;
plate 136, C, figures 35-49
Rostricellula rostrata UtricH and Cooper, Journ. Paleont., vol. 16, No. 5, p. 626, pl. go,
figs. 24, 28, 20, 32, 37, 1942.

Shell of about medium size for the genus, triangular to subpentagonal in out-
line ; brachial valve slightly deeper than the pedicle ; beak forming approximately
a right angle; greatest width at or slightly anterior to the middle; anterolateral
margins narrowly rounded, front margin broadly rounded. Surface costate, 3
to 5 costae occupying the sulcus and 4 to 6 defining the fold; flanks marked by
6 costae. Entire surface marked by fine radial and concentric lines that produce
granules where they intersect.

Pedicle valve moderately convex with the greatest convexity located from the
middle to the umbo. Posterior quarter and umbonal region moderately convex ;
sulcus originating about 6 mm. anterior of the beak, flat in profile, shallow, and
producing a short truncated tongue anteriorly. Sulcus occupies more than half
the width at the front. Flanks gently convex and with moderately steep slopes
to the margins.

Brachial valve evenly and strongly convex in lateral profile and strongly con-
vex in anterior profile; greatest convexity near the middle. Umbonal region
swollen; the fold originates about 5 mm. anterior to the brachial beak; posterior
to the fold a shallow and poorly defined sulcus marks the shell. Fold low, spread-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 649

ing gradually anteriorly, gently convex in profile; flanks moderately convex and
with moderately steep slopes to the margins.

Interior: Teeth small, supported by short dental plates separated from the
outside wall of the shell by narrow umbonal cavities ; pedicle callist slightly thick-
ened. Brachial valve with a high and thin median septum supporting a short,
shallow, and narrow cruralium which in turn supports a divided hinge plate.
Crura long, slender and curved.

Measurements in mm.—

Brachial
Length length Width Thickness
FAGIOUY PEM Macuser aaientes sat sk oes 14.3 12.7 14.4 8.6
Paratype, GlOSZ056)s i... ne ane a es 15.3 13.8 15.3 9.3

Types.—Holotype: 108205a; figured paratypes: 108205b-d,h ; unfigured para-
types: 108205¢,f,g ; figured hypotypes: 111531a,b, 111535, I11541a-c, 117226a,b,
117227.

Horizon and locality—Wardell formation in Tennessee: 7 miles southwest of
Clinton, Clinton (T.V.A. 137-SW) Quadrangle; 14 to 2 miles northeast of
Loyston, Maynardville (30’) Quadrangle.

Dryden formation in Tennessee: On the road to Tazewell, 14 miles northeast
of Lone Mountain, Tazewell (T.V.A. 154-NE) Quadrangle.

Ridley formation in Tennessee: 1 mile west of the courthouse in Murfrees-
boro, Murfreesboro (15’) Quadrangle.

Pierce formation in Tennessee: At Murfreesboro, Murfreesboro (15’) Quad-
rangle.

Wardell part of Dryden formation in Virginia: In a quarry just east of Vir-
ginia Highway 70, northeast of the Powell River, 1.6 miles south of Jonesville,
Ben Hur (T.V.A. 170-NE) Quadrangle ; quarry on Station Creek, $ mile south
of U. S. Highway 58, 2 miles east of Cumberland Gap, Wheeler (T.V.A.
153-SE) Quadrangle.

Discussion—This is a fairly large species with somewhat distant costae, a
moderately wide fold and sulcus, and triangular outline. It differs from R. plena
in its lesser convexity and more distant costae. It is suggestive of R. truncata,
but that species is much more strongly costate and is truncated anteriorly.
Rostricellula tumidula is a strongly costate Appalachian form, but its large size
and somewhat swollen valves are not likely to be confused with R. rostrata.

Rostricellula rostrata as here described and figured may be a composite species.
Specimens from the Benbolt-Wardell=Dryden shale with Dinorthis transversa
on the Tazewell road 14 miles northeast of Lone Mountain are not quite char-
acteristic in profile and are somewhat less wide anteriorly. These features may
be old age characters.

ROSTRICELLULA ROTUNDATA Cooper, new species
Plate 130, B, figures 12-22

Shell fairly large, somewhat elliptical in outline with the width greater than
the length; sides narrowly rounded; anterior margin nearly straight to slightly

650 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

convex; apical angle about 115°; sulcus occupied by 4 to 6 costae, fold by 5 to
7 costae, flanks with 9 costae. Surface marked by fine fila, often papillose.

Pedicle valve gently convex in lateral profile ; broadly convex in anterior pro-
file but with the median region gently concave. Sulcus originating about 6 mm.
anterior to the beak ; umbo somewhat swollen. Sulcus broad and shallow; tongue
moderately long. Median area swollen. Flanks flattened, moderately steep.

Brachial valve deeper than the pedicle valve, strongly convex in lateral profile,
broadly arched in anterior profile. Umbo swollen; median region swollen and
forming the most convex part of the valve; umbo moderately sulcate; fold low
and with rounded profile; width of fold at front about one-third the valve width.
Flanks rounded but with moderate slopes.

Measurements in mm.— rr ahil

Length length Width Thickness
Holotype es eS Ae Ga. 117 9.9 13.7; 8.6
Paratype |\(30550b) vss i. Circe 11.0 9.9 13.4 9.1
¥ GsGshoe) messed l.ceb 426 0.1 8.6 LL7 6.6
1 C:2D550d))« Bix sis ators afeh 8.2 Ue 8.8 5.3

Types—Holotype: 36550a; figured paratype: 36550b; measured paratypes:
365 50c,d.

Horizon and locality —Swift Current formation in Ontario, Canada: North-
east corner of St. Joseph Island, St. Marys River.

Discussion.—This species has been referred to R. ainslei and is quite suggestive
of that form because of its rounded contours, low beak, and transversely ellip-
tical outline. In spite of the similar appearance it is quite different. Rostricel-
lula rotunda is generally smaller than R. ainslei, is more rotund in lateral profile,
and has a lower and narrower fold.

ROSTRICELLULA SUBTRANSVERSA Cooper, new species
Plate 137, B, figures 7-19

Shell of about medium size for the genus, wider than long, with narrowly
rounded sides and somewhat truncated anterior margin. Apical angle varying
between go° and 100°. Sulcus marked by 5 or 6 costae, the fold by 6 or 7, and
the flanks by 6 to 10 costae. Entire surface crossed by fine elevated fila.

Pedicle valve gently convex in both profiles; umbo convex, beak strongly in-
curved. Sulcus originating 4 to 5 mm. anterior to the beak, broad and shallow.
Tongue moderately long. Flanks narrowly rounded and with moderate slopes.

Brachial valve considerably deeper than the pedicle valve, strongly convex in
lateral profile, and strongly arched with steep sides in anterior profile. Fold low,
not strongly defined at any point on its length; median region strongly inflated ;
flanks swollen and precipitous.

Measurements in mm.— cables

Length length Width Thickness
Holbetype’t soriwicetaun oidvins: oak 9.8 8.8 12.1 7.6
Paratype Cri 72280) ids OSL. 12.3 11.5 13.0 9.7

(1172286). esteeqer peas a2 >} 8.6 II.0 5.4

PART. \E CHAZYAN AND RELATED BRACHIOPODS—COOPER 651

Types.—Holotype: 117228b; figured paratypes: 117228a,c.

Horizon and locality—Witten formation in Tennessee: 4 mile south of Hei-
skell, Powell Station (T.V.A. 137-SE) Quadrangle; near Luttrell.

Discussion.—This species has been confused with FR. ainslei, but it is much
smaller and has different proportions. It is much more likely to be confused with
R. rotunda because, like that species, it has smooth rounded outlines and mod-
erate size. Rostricellula rotunda, however, has a less prominent fold in the adult
condition, is less deeply sulcate and somewhat deeper. Rostricellula transversa
is similar but is less numerously costate and is more strongly folded.

ROSTRICELLULA TRANSVERSA Cooper, new species
Plate 132, G, figures 38-42; plate 134, E, figures 47-53; plate 137, H, figures 53-60

Shell of about medium size for the genus with the width equal to about 14 times
the length ; beak obtusely angular, posterolateral margins straight, sides narrowly
rounded. Front margin truncated. Surface costate, 3 to 4 costae occupying the
sulcus and 4 to 5 forming the fold; flanks with as many as 8 costae.

Pedicle valve moderately convex with the greatest convexity located in the
posterior half. Umbo swollen and convex; sulcus originating about 4 mm. an-
terior to the beak, widening anteriorly to occupy about half the width at the
front. Tongue moderately long, truncated anteriorly. Umbonal slopes steep ;
flanks flattened in profile and with only moderately steep slopes to the margins.
Interarea small.

Brachial valve slightly deeper than the pedicle valve, evenly but moderately
convex with the maximum convexity at about the middle. Umbonal region flat-
tened ; umbo marked by a slight depression posterior to the fold which originates
about 24 mm. anterior to the beak. Fold flattened in anterior profile, moderately
elevated above the flanks. Steep slopes and a rounded profile characterize the
flanks.

Measurements in mm.—
Brachial

Length length Width Thickness
Holotypentitiy. “oot aed ee i..2 8.1 m3 10.6 5.8
Patatype GAtis45b)) iis. aspects bads.s's 9.1 8.7 11.9 6.2
+ (GR 210 A ee 10.2 9.3 um ie 7.0

Types.—Holotype: 111545a; figured paratype: 117229a; figured specimen:
117230; measured paratype: 111545b.

Horizon and locality——Bromide formation (Pooleville member) in Oklahoma
in Murray County: 15 feet below the top of the formation on Colbert Creek,
SW5 sec. 15, T. 1 S., R. 1 E., 5 miles southwest of Davis ; Spring Creek, N4 sec.
17, T.2S., R. 1 W., Murray County; in Pontotoc County on Oklahoma High-
way 99, 3 miles south of Fittstown. Mountain Lake, E4 sec. 22, T.2 S., R.1 W.,
Carter County ; NE# sec. 32, and SE sec. 33, T.2 S., R. 2 E., in Carter County ;
4 mile west of U. S. Highway 77, sec. 25, T. 2 S., R. 1 E., north of Ardmore,
Carter County.

652 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion —This species suggests a small R. laticosta (Winchell and Schu-
chert) but is more numerously costate. The species resembles R. rotunda but
does not attain the large size of that species nor does it have as deep a sulcus.
This species as here identified is somewhat variable. More extensive collections
will probably indicate further refinement of the species.

ROSTRICELLULA TRIANGULATA Cooper, new species
Plate 133, A, figures 1-11

Camarotoechia pristina TWENHOFEL and WuiITING (not Raymond), Geol. Soc. Amer. Special
Pap. 15, p,. 52, pl. 8, figs, 1:2; 1978.

Shell small, triangular in outline with acute beak (72°) and nearly straight
sides to the anterolateral extremities which are narrowly rounded. Anterior
margin broadly rounded. Brachial valve slightly deeper than the pedicle valve.
Surface costate, sulcus occupied by 4 or 5 costae, the fold by 5 or 6, and the
flanks by about 5.

Pedicle valve gently but evenly convex in lateral profile, posterior half mod-
erately convex, with a long narrow beak and narrowly rounded umbo; sulcus
originating about 4 mm. anterior to the beak and near the middle of the valve,
shallow, flat to convex in profile; tongue short and broadly rounded. An-
terolateral extremities moderately elevated; flanks narrowly convex and with
steep lateral slopes.

Brachial valve gently convex with the maximum convexity in the median
region; broadly convex in anterior profile; fold not conspicuous, only slightly
elevated at the front; flanks rounded and with moderately steep slopes.

Measurements in mm.—
Brachial

Length length Width Thickness
Polotypet.t wrens daha sels Mode eee ve 6.4 7.2 4.0
PAGANO: ao ace th Scos shot ase bdors ane 6.7 6.1 6.0 33

Types.—Holotype: 111549a; figured paratype: 111549b.

Horizon and locality—Mingan formation (60 to 70 feet above the base) :
Bald Island, Mingan group, St. Lawrence River, Quebec, Canada.

Discussion.—This species differs from R. pristina, with which it was formerly
confused, in its more triangular form and more numerous costae in the fold and
sulcus. It differs in the same respects from R. basalaris. It is more finely costate
than Fe. costata and is not so deep as that species.

ROSTRICELLULA TRUNCATA Cooper, new species
Plate 134, B, figures 19-26

Shell of about medium size for the genus, wider than long, and broadly tri-
angular in outline. Apical angle about 100°. Posterolateral margins straight,
anterolateral extremities narrowly rounded; anterior margin truncated. Costae
strong, narrowly rounded, 4 on the fold, 3 in the sulcus, and 4 to 6 on the flanks.

Pedicle valve shallow and only gently convex in lateral profile, broadly concave

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 653

in anterior profile. Sulcus originating about 5 mm. anterior to the beak, broad
and shallow; tongue short, truncated. Flanks narrow and steep sided.

Brachial valve slightly deeper than the pedicle valve, gently convex in lateral
profile ; broadly convex in anterior profile and somewhat flattened in the middle;
fold originating just posterior to the middle, flattened, not strongly elevated.
Flanks narrowly rounded and steep sided.

Measurements in mm.—Holotype, length 13.3, brachial length 11.8, width 15.8,
thickness 9.6.

Type.—Holotype :117231.

Horizon and locality—Lebanon formation in Tennssee: On U. S. Highway
41, $ mile south of Knox Branch, 9 miles southeast of Murfreesboro, Rutherford
County.

Discussion.—This species is characterized by its strong and distant costae and
the marked truncation of the anterior end. It is most like R. angulata in its
strong costation but differs in its anterior truncation and in having more numer-
ous costae on the fold and in the sulcus.

ROSTRICELLULA TUMIDULA Cooper, new species
Plate 131, C, figures 17-27

Shell large for the genus, subtriangular in outline; valves subequal in depth.
Beak approximating a right angle; anterolateral extremities narrowly rounded ;
anterior margin broadly rounded to nasute. Surface costate, sulcus occupied by
5 to 7 narrowly rounded to subangular costae separated by spaces equal in width
to the costae; fold marked by 6 to 8 costae and the flanks by 5 to 7 costae.

Pedicle valve moderately convex in lateral profile, with the greatest convexity
at about the middle; posterior third and umbonal region gently swollen; sulcus
originating about 7.5 mm. anterior to the beak; sulcus broad and shallow, equal
in width to more than half the width of the valve; tongue moderately long,
broadly rounded. Flanks moderately rounded and with moderate slopes to the
margins.

Brachial valve fairly strongly convex in lateral profile and with the maximum
curvatures at about the middle. Fold not strongly defined, originating about
6 mm. anterior to the beak, gently rounded in anterior profile; only slightly ele-
vated at the front. Flanks rounded in profile but with steep lateral slopes. Um-
bonal and median regions swollen.

Measurements in mm.—

Brachial
Length length Width Thickness
Pipl type jatar ot diss’ l prep: aney 20.6 18.1 20.1 13.3
Patatypey (o8to6a) 0.5... e6es 18.3 16.7 16.6 12.8
+ CORIOGE) |S etl es sine ian 17.5 15.5 17.9 12.0

Types.—Holotype: 98196b ; figured paratypes: 98196a,c.

Horizon and locality—Dryden formation in Virginia: 4 mile west of Fullers
Corner, I mile south-southeast of Big A Mountain, Big A Mountain (T.V.A.
204-SE) Quadrangle.

654 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion.—The large size and tumid form of this species suggest FR. plena,
but that species possesses more numerous costae and more triangular form.
Rostricelllula tumidula approaches FR. major in size but differs in having more
and finer costae.

ROSTRICELLULA VARIABILIS Cooper, new species
Plate 133, C, figures 13-19; plate 133, D, figures 20-26

Shell of about medium size, outline variable from oval to subtriangular with
length greater or less than width; apical angle varying from 85° to 100°. Sulcus
with 4 or 5 rounded costae, fold with 5 or 6 costae, and the flanks with 6 or 7
costae.

Pedicle valve gently convex in lateral profile, with the maximum curvature
in the umbonal region. Anterior profile broadly or flatly convex. Sulcus origi-
nating about 4 mm. anterior to the beak, shallow throughout its extent. Tongue
short. Sulcus occupying more than half the width. Flanks narrow and rounded
with steep sides.

Brachial valve deeper than the pedicle valve, moderately convex in lateral pro-
file, fairly strongly convex in anterior profile. Umbonal region flattened and
narrowly sulcate. Fold low throughout its length, only slightly elevated above
the flanks anteriorly. Flanks swollen, rounded and with precipitate sides.

Measurements in mm.—

Brachial
Length length Width Thickness
TEAGUE one ek Oe eek. 73:3 12.1 II.9 7.2
Paratyoe ss 49 .CRAae. PR 10.0 9.5 10.8 7a,

Types.—Holotype: 117232; figured paratype: 117233.

Horizon and locality Ridley formation (Fascifera bed) in Georgia: 1 mile
south-southeast of Cove Church, 5 miles south of Chickamauga, Kensington
(T.V.A. 106-SE) Quadrangle.

Discussion.—This species is characterized by its moderate size, subtriangular
form and moderately wide sulcus with 4 or 5 costae. It shows considerable varia-
tion in the development of the fold and sulcus, the larger specimens having the an-
terior somewhat elongated or subnasute and the costae more spread out than in
the younger stages. The elongate form suggests R. ovata because of its length
but is not so numerously costate. The younger forms are not unlike R. pulchra
or R. missouriensis. It differs from the former in much smaller size and in hav-
ing a somewhat narrow and more pronounced fold than those features on the
corresponding size in R. pulchra. Rostricellula missouriensis in stages having
the same length as FR. variabilis is not so deep and has a wider and more pro-
nounced fold.

ROSTRICELLULA VARICOSTA Cooper, new species
Plate 139, C, figures 23-36

Shell small, variable in outline and costation ; subtriangular to oval in outline;
apical angle varying from about 85° to 100°. Posterolateral margins straight;

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 655

anterolateral margins narrowly rounded; anterior margin broadly rounded; sur-
face marked by rounded costae: 4 to 7 on the fold, 3 to 6 on the sulcus, and 5 to
8 on the flanks.

Pedicle valve with lateral profile fairly evenly and moderately convex ; anterior
profile broadly and gently convex; umbonal and median regions somewhat nar-
rowly swollen; sulcus originating at the middle, shallow and wide; tongue
broadly rounded but fairly short. Flanks narrowly rounded, with steep sides.

Brachial valve moderately convex in lateral profile, fairly strongly convex in
anterior profile; umbonal and median regions moderately swollen; sulcus origi-
nating at about the middle, low throughout its length and not markedly differ-
entiated from the flanks which are swollen and have steep slopes to the margins.

Measurements in mm.—

Brachial Max.
Length length width Thickness
AAU os, o sia\eic-01s on s)ae se saw dee 8.6 78 9.5 5.2
aGAEU DE LE Tae AOD) cee cee s,s a scons 9.0 8.2 8.90 6.4.
HS GUE7Z238C) Is cueau"s sea once 0.5 8.7 9.9 6.2
S GRITII0) scale te ou nede 0.1 8.2 0.1 5.3
* MPTP SI0E) choos cscs e wwe 7.8 7.2 7.8 4.5

Types.—Holotype: 117238; figured paratype: 117238b; unfigured paratypes:
117238c-e.

Horizon and locality—Lenoir formation (Douglas Lake member) in Ten-
nessee: 0.65 mile southwest of Williamson Chapel, Tallassee (T.V.A. 139-SE)
Quadrangle.

Discussion—This species is characterized by moderate size, nearly equal
length and maximum width, wide fold and sulcus, and numerous costae. Al-
though it suggests R. raymondi, that species is much more strongly costate.
Rostricellula basalaris occurs at about the same level but is more triangular in
outline and is somewhat more strongly costate. Rostricellula multicostata also
occurs at the same level, but it is much larger and has a more pronounced fold
which is marked by about the same number of costae as in the Tennessee species.
However, the Virginia species has more costae on the flanks than the Tennessee
form.

The base of the Lenoir or its equivalent in many places in the Appalachian
Valley is marked by abundance of Rostricellula. Often the rock is so filled with
these rhynchonellid shells that no other species are to be found. It is odd that
from place to place these shells seem to vary specifically. They were undoubtedly
controlled by environmental conditions that varied geographically. Evidence of
such geographic variation is encountered also in other places and other strata
and will one day form a fruitful subject for investigation.

ROSTRICELLULA WILSONAE Cooper, new species
Plate 135, F, figures 36-48

Shell of about medium size for the genus, slightly wider than long, sides nar-
rowly rounded and greatest width just anterior to the middle. Apical angle ap-

656 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

proximately 90°. Sulcus marked by 4 to 6 narrowly rounded, slender costae,
fold marked by 5 to 7 costae, and the flanks by 7 or 8 costae.

Pedicle valve unevenly and gently convex in lateral profile, the most convex
part located just anterior to the umbo; anterior profile broadly convex and with
the median region slightly depressed. Beak strongly incurved and overhanging
the umbo of the brachial valve. Umbo moderately swollen; sulcus originating
just posterior to the middle or about 5 mm. anterior to the beak. Sulcus mod-
erately deep; tongue short, not geniculated. Flanks flat, moderately sloping.

Brachial valve deeper than the pedicle valve, moderately convex in lateral pro-
file, moderately strongly arched in anterior profile. Umbo strongly swollen,
marked medially by a shallow and narrow sulcus. Fold becoming defined near
the middle, not strongly elevated at any point on its length. Flanks rounded and
moderately steep.

Measurements in mm.—
Brachial

Length length Width Thickness
BIDIOLY PE |. Soe vicecc os HOE ate ote Se 11.8 10.7 12.9 72
Paratype eee sie ee ate 17 10.3 10.6 8.9

Types.—Holotype: 117234a; figured paratype: 117234b.

Horizon and locality—Aylmer formation (Rockcliffe member) in Ontario,
Canada: 2 miles south of Rockland.

Discussion.—This species has been commonly referred to R. plena in the re-
gion around Ottawa. In appearance R. wilsonae is suggestive of that species but
does not attain its large size or great depth. R. plena of the same size as R. wil-
sonae is much deeper, has a shallower sulcus and a more triangular shape than
the Ottawa species. The deeper varieties of R. wilsonae compared with speci-
mens of FR. plena of the same length have a deeper sulcus.

ROSTRICELLULA sp. 1
Plate 137, G, figures 47-52

Small, length and width nearly equal; fold marked by 3 costae, the sulcus by
2. Flanks marked by 5 or 6 costae. Valves subequal in depth; sulcus originat-
ing near the middle ; fold low; tongue short.

Measurements in mm.—Figured specimen, length 6.2, brachial length 5.5,
width 6.4, thickness 4.8.

Figured specimen.—117236.

Horizon and locality—Bromide formation (Pooleville member—bed E of
Cooper) in Oklahoma: On Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray
County.

Discussion.—A single specimen was found in this bed of the Bromide, and
no other members of the genus were taken from that part of the column. The
present specimen, in its thickened shell and strongly marked interrupted growth
stages, is obviously not a normal specimen. Abnormality is further emphasized
by the presence of a bifurcated costa which is exceptional in this genus of
rhynchonellids.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 657

ROSTRICELLULA sp. 2
Plate 131, D, figures 28-32

Shell small, length and width about equal; apical angle about 95°. Greatest
width anterior to the middle. Costae numbering 5 on the fold, 4 in the sulcus,
and 7 or 8 on the flanks.

Pedicle valve slightly less deep than the brachial valve and with a moderately
convex lateral profile. Anterior profile broadly and gently convex. Sulcus origi-
nating 5 mm. anterior to the beak ; umbo gently rounded; sulcus shallow, occupy-
ing about half the width. Tongue long and narrow. Flanks narrow and steeply
descending to the margins.

Brachial valve with lateral profile like that of the pedicle valve; anterior pro-
file moderately strongly convex; umbonal region moderately swollen; fold low
and rounded, not elevated strongly at the anterior. Flanks rounded and with
precipitous sides.

Measurements in mm.—117235, length 8.1, brachial length 7.4, width 8.3,
thickness 5.7.

Figured specimen.—117235.

Horizon and locality—Upper Wardell formation in Virginia: At Mannville
School, Clinchport (T.V.A. 188-NW) Quadrangle.

Same (?) horizon in Tennessee: On Little Mulberry Creek on the road up
Sycamore Valley, Back Valley (T.V.A. 161-SE) Quadrangle.

ROSTRICELLULA sp. 3
Plate 139, E, figure 54

A figure of this specimen is introduced to show the character of the micro-
ornamentation common to many species of Rostricellula. This consists of fine,
wavy, concentric fila. These are irregular and often somewhat discontinuous.
They are also variable in the degree to which they approach fine lamellae and
are often longer in the swales between the costae than on the sides and are fre-
quently worn off the crests of the costae. In places where variable in length
these fila or minute lamellae give the impression that the surface is granulose.

Figured specimen.—117237.

Horizon and locality—Lower Prosser formation in Minnesota: In the road
cut 1.2 miles east of U. S. Highway 52 on the south edge of Cannon Falls,
Goodhue County.

Family LEPIDOCYCLIDAE Cooper, new family
Rhynchonellacea with concave deltidial plates (?) in the pedicle valve and a

cardinal process in the brachial valve.

Genus LEPIDOCYCLUS Wang, 1949
Lepidocyclus Wane, Geol. Soc. Amer. Mem. 42, p. 12, 1949.

658 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

LEPIDOCYCLUS sp. 1
Plate 130, G, figures 36, 37

Views of the interior of the pedicle and brachial valves of Lepidocyclus are
introduced for comparison with the same views of Rostricellula and Rhyn-
chotrema.

Figured specimens.—117209a,b.

Horizon and locality—Fernvale formation, in Oklahoma: Quarry at Law-
rence, southwest of Ada, Pontotoc County.

Family OLIGORHYNCHIIDAE Cooper, new Family

Small, strongly costate shells with small triangular deltidial plates and strong
dental lamellae in the pedicle valve ; brachial valve with long crura supported by
delicate, discrete plates.

Genus OLIGORHYNCHIA Cooper, 1935
Oligorhynchia Coorer, Amer. Journ. Sci., vol. 29, p. 49, 1935.

Shell small, triangular in outline, biconvex; beak nearly straight. Anterior
commissure intraplicate. External surface costate. Foramen elongate-oval, del-
tidial plates small, triangular.

Dental plates of pedicle valve strong, divergent ; teeth long and slender, curved.

Notothyrial cavity long, moderately deep, narrow; sockets deep; socket ridges
high; hinge plate divided, supported by thin, delicate convergent plates; crural
bases triangular; crura long, nearly straight or curved, and extending almost
directly anteriorly or obliquely toward the pedicle valve. Hinge plate supported
by inner swelling of posterior of valve which forms the median sulcus at the
posterior of the brachial valve. Musculature unknown.

Genotype——Oligorhynchia subplana Cooper, Amer. Journ. Sci., vol. 29, p. 49,
1935.

Discussion.—Acquisition of material that could be etched to expose the crural
plates well is the basis for the revised generic description above. The specimens
came from the belt of shale and limestones (Hogskin member of the Lincoln-
shire formation) that extends from Thorn Hill, Tenn., to Washburn, Luttrell,
and Speers Ferry, the same belt that produced the type specimens. The new
material presents the hinge plate and shows it to be attached to the inner swell-
ing of the valve produced by the sulcus at the posterior end and further sup-
ported by delicate converging plates. This sulcus in a short distance suddenly
reverses to become a strong median elevation. The hinge plate is divided and
consists of triangular outer hinge plates and strong, elevated socket plates that
define the deep socket. The crura are shown by three specimens to have been
long simple rods extending nearly straight into the valve in an anterior direction.
A third specimen somewhat deeper than the others and approaching O. subplana
gibbosa shows the crura to be curved and extended obliquely toward the pedicle
valve.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 659

Oligorhynchia is at present known only from the Southern Appalachians in
the United States. It is also present, if interpretation of Cowper-Reed’s figures
is correct, in the Balclatchie and Stinchar limestones of the Girvan District, Scot-
land. The specimens described by Cowper-Reed as Camarella ? conybearet seem
to belong to this genus, at least from their external appearance. No details of
the interior are given in the description, but figure 23 on plate 22 (Reed 1917)
shows short dental plates not unlike those seen in Oligorhynchia in the
Appalachians.

OLIGORHYNCHIA ANGULATA Cooper
Plate 125, C, figures 37-46; plate 125, D, figures 47-49; plate 126, C, figures 10-12;
plate 127, B, figures 9-13
Oligorhynchia angulata Cooper, Amer. Journ. Sci., ser. 5, vol. 29, p. 52, pl. 1, figs. 6, 7, 9-11,
1935.

Types.—Lectotype: Y.P.M. S2258; figured hypotypes: U.S.N.M. 117195a-c,
117196, 118017; paratype: Y.P.M. S2259.

Horizon and locality—tLincolnshire formation (Hogskin member) in Ten-
nessee: At Luttrell, Luttrell (T.V.A. 155-NW) Quadrangle, and Washburn,
Dutch Valley (T.V.A. 154-SE) Quadrangle; on the road to Washburn, 3, 4,
and 44 miles west-southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quad-
rangle; # mile southwest of Mount Eager Church, Hogskin Valley, Powder
Springs (T.V.A. 154-SW) Quadrangle; 4 mile southwest of Fleanor Mill and
200 yards north of the highway, Powell Station (T.V.A. 137-SE) Quadrangle.

Sevier formation in Tennessee: + mile north of Gooseneck, southwest corner
Louisville (T.V.A. 138-SE) Quadrangle; slope on the west side of the church
in Guthrie Gap, 2 miles south-southeast of Whitehorn, Bulls Gap (T.V.A.
17I-SE) Quadrangle; 1.3 miles south of the center of Athens, Athens (T.V.A.
125-NE) Quadrangle.

Ward Cove formation in Virginia: On Wallen Creek, east of Virginia High-
way 70 at Glass’s store, 54 miles southeast of Jonesville, Ben Hur (T.V.A.
170-NE) Quadrangle.

OLIGORHYNCHIA BIFURCATA Cooper, new species
Plate 126, D, figures 13-24; plate 127, A, figures 1-8
Oligorhynchia sp. Butts, Virginia Geol. Surv. Bull. 52, pl. 87, figs. 18, 19, 1942.

Shell small, elongate triangular in outline, compressed in both profiles; beak
erect and sharply pointed ; surface strongly costate.

Pedicle valve with deep sulcus extending from beak to anterior margin and
occupied by a single costa located in the front third of the sulcus. Sulcus bounded
by strong angular, elevated costae with 2 low costae on each side.

Brachial valve faintly sulcate at the umbo but with a widening sulcus anteriorly
which is occupied by a single strong costa bifurcated at its front end to accom-
modate the small costa of the pedicle sulcus. Flanks of costae bounding sulcus
with a low costa.

660 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial
Length length Width Thickness
Pitatyper ss.) suite gacaoieeei. 5.1 4.7 6.0 ? 1.7
Paratype, (98205) 5)0'.)s ube Peaakh os 5.0 4.8 37 2.5

Types.—Holotype: 117197a; figured paratypes: 98205, 117197b,c, 117198a,b,
118025 ; measured paratype: 98205.

Horizon and locality—Benbolt formation in Virginia: In the road cut on
U. S. Highway 19, 14 miles southeast of Hansonville, Brumley (T.V.A. 205-SE)
Quadrangle; Miller Farm on northwest slope of Wallen Ridge, about 2 miles
southeast of Ollinger, Ollinger (T.V.A. 178-SE) Quadrangle; 4 mile north-
west of Rye Cove, Clinchport (T.V.A. 188-NW) Quadrangle.

Benbolt? formation in Virginia: 44 miles southwest of Bland, Bland County.

Edinburg formation (St. Luke facies) in Virginia: On Swover Creek, 4.6
miles N. 69° W. of Edinburg, near Lantz Mills, Edinburg (15’) Quadrangle.

Witten formation in Virginia: On Virginia Highway 81, 14 miles southwest
of Tazewell, Tazewell (15’) Quadrangle; at turn of the road southwest of Jeff
Gillespie’s on Virginia Highway 88, 14.4 miles west-southwest of Tazewell.

Surgener formation (red beds) in Tennessee: On the roadside 0.3 miles north
of the Church at Rose Hill, Maynardville (T.V.A. 145-SE) Quadrangle.

Wardell-Witten (=Dryden) formation in Tennessee: On the east side of
Long Branch 1.3 miles northeast of Lone Mountain Station, Tazewell (T.V.A.
154-NE) Quadrangle; Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle;
bed 41, opposite Thorn Hill store on U. S. Highway 25E, Avondale (T.V.A.
162-SW) Quadrangle ; above old marble quarry, $ mile southeast of Hambright
Mine, 8 miles south of Cleveland.

Ward Cove formation ? in Tennessee: Mulberry Gap, 4 miles north-north-
west of Sneedville, Back Valley (161-SE) Quadrangle.

Benbolt formation in Virginia: 4 mile southeast of Richpatch, Eagle Rock
(15’) Quadrangle; on Virginia County Highway 616, 0.6 mile northwest of the
junction with County Highway 621, Richpatch, Eagle Rock (15’) Quadrangle.

Discussion.—This species is characterized by a short plication in the front part
of the sulcus of the pedicle valve and a bifurcation of the median fold of the op-
posite valve to produce a sulcus in the fold for the accommodation of the median
plication. The only other species like this one is O. elongata, but that species
differs in other respects. It is long and slender and scarcely expanded anteriorly,
whereas O. bifurcata is fairly broadly triangular and fairly wide anteriorly.

OLIGORHYNCHIA ELONGATA Cooper, new species
Plate 126, A, figures 1-5

Shell small, elongate triangular in outline, compressed in lateral profile ; widest
at the front; sides nearly straight; apical angle about 40°. Sides flattened.
Brachial valve slightly deeper than the pedicle valve. Widest at the front.

Pedicle valve gently convex in lateral profile, marked by 2 strong elevated and
subangular costae that bound a deep but narrow sulcus; sulcus occupied by a

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 661

single small costa extending not quite to the middle. Flanks marked by 2 costae,
I strong one depressed below the 2 bounding the sulcus, and a fine costa on the
lateral slopes.

Brachial valve more convex than the pedicle valve, marked by a deep and wide
median sulcus extending from a point about 4 mm. from the beak to the anterior
margin; sulcus occupied by a single angular costa that bifurcates at about the
middle of the valve. Flanks marked by 2 costae fairly strong and a third
weaker one on the outer slope.

Measurements in mm.—Holotype, length 4.6+, brachial length 4.6, width 3.0,
midwidth 2.6, thickness 2.4.

Type.—Holotype: 118016.

Horizon and locality.—Wardell formation (between the Sowerbyella and Hes-
perorthis beds) in Tennessee: In the road cut north of Indian Creek on U. S.
Highway 25E, Howard Quarter (T.V.A. 162-NW) Quadrangle.

Discussion.—This species is suggestive of O. bifurcata because of the bifurcated
costa in the brachial sulcus, but it differs in its more slender form and details of
the ornamentation.

OLIGORHYNCHIA INEXPECTATA Cooper, new species
Plate 124, D, figures 24, 25

Shell small for the genus, outline narrowly triangular with the pedicle valve
having the greater depth. Sides nearly straight. Valves costate.

Pedicle valve nearly flat in lateral profile but with the umbonal region slightly
convex ; anterior profile narrowly convex; beak and umbo smooth; umbo and
postmedian region carinate ; sulcus shallow, narrow and originating at about the
valve middle; sulcus bounded by 2 strong subcarinate costae elevated above the
flanks and forming a fold; sides marked by 2 oblique, narrow costae.

Brachial valve gently and evenly convex in lateral profile; narrowly convex
in anterior profile and with steep, precipitous sides; sulcus narrow at the pos-
terior, originating at the umbo and extending to the anterior margin; sulcus wid-
ening strongly at the middle and occupied by a single costa that originates at the
middle; flanks narrowly rounded, marked by a bounding strong costa on each
side of the fold and 2 finer costae on the sides.

Measurements in mm.—

Brachial Widest
Length length Midwidth part Thickness
Holotype (pedicle valve)........ 3.3 ? 1.8 2.2 1.1
Paratype (brachial valve)....... ? 2.7 1.8 1.8 0.7

Types.—Holotype: 117203a; figured paratype: 117203b.

Horizon and locality.—Red Knobs formation (between the Athens cobbly beds
and the marble) in Tennessee: On the roadside along Hiwassee River, 14 miles
southeast of Charleston, Calhoun (T.V.A. 125-SW) Quadrangle.

Discussion.—This species is characterized by its small and slender form, the
short sulcus in the pedicle fold, and the narrow rib in the sulcus of the brachial

662 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

valve. This group of characters is unlike that of any other species. In the other
described species the sulcus in the pedicle fold originates farther toward the pos-
terior and the costa of the sulcus in the brachial valve is stout and angular rather
than slender as in O. inexpectata.

OLIGORHYNCHIA SUBPLANA Cooper
Plate 124, B, figures 14-17; plate 124, EF, figures 26-31; plate 125, B, figures 16-36;
plate 125, C, figures 37-46; plate 125, D, figures 47-49
Oligorhynchia subplana Coorer, Amer. Journ. Sci., ser. 5, vol. 20, pp. 49-52, pl. 1, figs. 2, 8,
13, 14; text figs. I-4, 1935.

This species differs from O. angulata Cooper in its narrower outline, less angu-
lar folds, and its ornamentation.

Types.—Holotype: Y.P.M. S2251; paratypes: Y.P.M. S2253-2257; figured
hypotypes: 118014, 117200a,b, 117201a,b, 117202a,b.

Horizon and locality—Lincolnshire formation (Hogskin member) in Tennes-
see: At Luttrell, Luttrell (T.V.A. 155-NW) Quadrangle; 3 to 44 miles west-
southwest of Thorn Hill on the road to Washburn, Avondale (T.V.A. 162-SW)
Quadrangle; 2 miles southwest of Hall Crossroad, Fountain City (T.V.A.
146-SW) Quadrangle; south side of the school just north of Chesney railroad
crossing, Luttrell (T.V.A. 155-NW) Quadrangle; Maynardville Pike, 1.7 miles
north-northeast of Hall Crossroad, Fountain City (T.V.A. 146-SW) Quad-
rangle; on U. S. Highway 25E, 3 mile north of Indian Creek, Howard Quarter
(T.V.A. 162-NW) Quadrangle; 4 mile southwest of Fleanor Mill, 200 yards
north of the highway, Powell Station (T.V.A. 137-SE) Quadrangle; 3 mile
southwest of Mount Eager Church, Hogskin Valley, Powder Springs (T.V.A.
154-SW) Quadrangle.

Ward Cove formation in Tennessee: 3 mile southwest of Mount Eager Church,
Hogskin Valley, Powder Springs (T.V.A. 154-SW) Quadrangle.

Sevier formation in Tennessee: + mile northeast of Miser, Louisville (T.V.A.
138-SE) Quadrangle.

Lincolnshire formation in Virginia: 33 feet above the base, along the highway
beside Tumbling Run, 14 miles southwest of Strasburg, Strasburg (15’)
Quadrangle.

OLIGORHYNCHIA SUBPLANA GIBBOSA Cooper
Plate 125, A, figures 1-15; plate 125, E, figure 50
Oligorhynchia subplana gibbosa Coorer, Amer. Journ. Sci., ser. 5, vol. 20, p. 52, pl. 1, figs. 1,
3-5, 12, 1935.

Types.—Holotype: Y.P.M. S2252; figured hypotypes: 90751, 111304.

Horizon and locality—tLincolnshire formation (Hogskin member) in Ten-
nessee: 3 to 44 miles west-southwest of Thorn Hill on the road to Washburn,
Avondale (T.VA. 162-SW) Quadrangle; Luttrell, Luttrell (T.V.A. 155-NW)
Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 663

OLIGORHYNCHIA sp. 1
Plate 268, I, figures 41-44

A few specimens of Oligorhynchia were taken from a limestone 0.7 mile south
of Mooney Cemetery on the Bulls Gap (T.V.A. 171-SE) Quadrangle. The hori-
zon represented is either high in the Benbolt or low in the Wardell formations
(=Dryden formation where indivisible). It is uncertain which is the correct
horizon, but the specimens occur a considerable distance above a sandstone
containing Dinorthis transversa Willard.

The specimens appear not to belong to O. bifurcata because they do not possess
the characteristic forking of the median fold in the brachial valve. The specimens
are like O. angulata, but the fold of the brachial valve seems to be lower and the
shell is not so wide anteriorly.

Figured specimen.—118018a.

SPHENOTRETA Cooper, new genus

(Greek sphen, wedge; tretos, opening)

Shell small, triangular to oval in outline, apical angle acute; anterior commis-
sure more or less deeply sulcate; surface costate. Foramen large, longitudinally
elliptical or oval; deltidial plates small, triangular, located at the anterior end
of the foramen.

Pedicle interior with short divergent dental plates. Other details not determin-
able in material available.

Brachial valve with divided hinge plate; crural bases small, triangular ; crura
long and slender, directed obliquely anteriorly and slightly toward the pedicle
valve.

Genotype.—S phenotreta cuneata Cooper, new species.

Discussion.—All the material on which this genus is based consists of small
specimens, mostly below 5 mm. in length. Generally the shells are filled with
crystalline calcite, but the structures are so delicate that they are only visible
with difficulty when the shell is removed. The members of this genus have
hitherto been placed under Zygospira, this association having been inspired by
the strong pedicle folding and deep sulcation of the brachial valve which are
features of the early spire-bearer. All details of the interior of Sphenotreta de-
termined in this work indicate that this genus is a rhynchonellid and not an early
spire-bearer. Of the many specimens dissected not one showed any trace of a
spire.

This genus is similar to OligorhyncMia in external form and interior. The type
of folding is similar in the genera except that Sphenotreta does not develop a
fold in the brachial sulcus. The two genera differ in ornamentation rather
strongly. Oligorhynchia has a few strong costae only, whereas Sphenotreta is
wholly costate.

Internally the two genera are similar in having long, slender crura. Further
comparison is almost futile because details of the hinge plate of Sphenotreta are
not yet determined. It is evident, however, from what can be seen, that Spheno-

664 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

treta had very delicate and small hinge plates which contrast quite strongly with
the large structures of Oligorhynchia. The pedicle beak structures of the two
genera seem to be identical.

One poorly preserved brachial interior shows clearly one of the roles of the
brachial sulcus. This deep exterior trough serves as a median ridge in the interior
of the valve. The sulcation is so strong and deep that the inner manifestation of
this structure appears as a high, narrowly rounded ridge.

Sphenotreta appears first in the Crown Point formation of the Chazy group
but extends upward into the Sevier formation. It occurs with Oligorhynchia
in the latter formation. The genus occurs in crystalline limestones or cal-
carenites and in soft shale. It is in the former type of matrix in the Lenoir and
Sevier formation but occurs in soft shale in the McLish formation of Oklahoma.

SPHENOTRETA ACUTIROSTRIS (Hall)
Plate 124, F, figures 32-38; plate 143, H, figures 37-40
Atrypa acutirostra Hatt, Pal. New York, vol. 1, p. 21, pl. 4 bis, fig. 6, 1847.
Rhynchonella acutirostris (HALL), 12th Ann. Rep., New York State Cab. Nat. Hist., p. 65,
1850.

Zygospira acutirostris (Hall) Raymonp, Ann. Carnegie Mus., vol. 7, No. 2, p. 227, pl. 34,
figs. 15-22, IQII.

Shell small, triangular in outline with the widest part in the anterior
half; posterolateral margins straight, forming an angle of 80°. Anterolateral
margins narrowly rounded; anterior margin truncated ; anterior commissure sul-
cate. Surface marked by Io to 15 narrowly rounded to subangular costae.

Pedicle valve gently and evenly convex in lateral profile; broadly subcarinate
in anterior profile. Umbo narrowly convex, marked by a prominent median costa
which extends from umbo to anterior margin maintaining its prominent char-
acter throughout. Median costa and 1 or 2 on each side form an indistinct fold.
Flanks sloping moderately to the margins, not swollen.

Brachial valve gently convex in the median three-fourths but turned in nar-
rowly toward the pedicle valve in the anterior quarter. Anterior profile sulcate,
with narrowly convex flanks and precipitous sides. Umbo and median region
sulcate; sulcus deep, deepest medially where a narrow groove corresponds to
the exaggerated median costa of the pedicle valve. Sulcus occupied by 2 to 4
costae depending on age.

Measurements in mm.—

Brachial Greatest
Length length Midwidth width Thickness
Hypotype (pedicle valve 118019a)..... 37 ? 2.7 3.4 1.0
si (brachial valve 118019b).... ? 3.4 Pals 3.2 0.9
¢ ete HY wEESOOC). or ie 3.6 a, 3.4 0.7

Types.—Figured hypotypes: Carnegie Mus. 5439, 5440 (one without num-
ber) ; U.S.N.M. 118015; measured hypotypes: 118019a-c.

Horizon and locality—Crown Point formation in New York: at Chazy,
Rouses Point (15’) Quadrangle; Valcour Island, Plattsburg (15’) Quadrangle ;
Crown Point, Port Henry (15’) Quadrangle.

PART, J CHAZYAN AND RELATED BRACHIOPODS—-COOPER 665

Same formation in Vermont: At Isle LaMotte, Rouses Point (15’) Quad-
rangle; near Fort Cassin, Port Henry (15’) Quadrangle.

Discussion.—This species is characterized by strong, somewhat distant costae,
deep sulcus, and prominent median costa. It is similar to S. cuneata, but that
species is more deeply sulcate, narrower, and more strongly costate. Its orna-
mentation is arranged on a different pattern with 5 costae forming the fold.

SPHENOTRETA CUNEATA Cooper, new species
Plate 124, 1, figures 46-54

Shell small, elongate triangular in outline; sides nearly straight and forming
an apical angle of 65°; anterolateral extremities narrowly rounded; anterior
margin broadly rounded ; widest at the front; anterior commissure sulcate ; sur-
face with about 12 rounded to subangular costae, 4 of which occupy the sulcus.

Pedicle valve gently convex in lateral profile, broadly convex in anterior pro-
file. Umbonal region narrowly swollen. Median costa larger than all the others
and extending from umbo to anterior margin as a high ridge. Median costa with
2 depressed costae on each side forming a fascicle corresponding to the median
fold and opposing the 4 costae of the sulcus of the brachial valve. Flanks slightly
elevated above the fold but not above the median costa; flanks narrow and
marked by about 3 costae.

Brachial valve moderately convex in lateral profile, more convex than the
pedicle valve; anterior profile deeply sulcate and with precipitous lateral slopes.
Umbo sulcate; sulcus widening and deepening anteriorly to the front margin
where it occupies about three-fifths the width. Median slopes long and steep to
the bottom of the subangular sulcus, each slope occupied by 2 costae. Flanks
narrowly rounded.

Measurements in mm.—

Brachial Greatest
Length length Midwidth width Thickness
PA UOER EH oiela aisles Weraas tei dia oon 3.8 3.5 22 2.8 igs
Paratype (pedicle valve 117189b). 4.8 ? a3 4.3 1.2?
a (brachial valve 117180c) ? 4.5 3.0 3.9 ?
af ‘ Oeiiees rT EEF TOOR) r 4.6 3.6 4.8 0.9?

Types.—Holotype: 117189a; figured paratypes: 117189b-d,g ; unfigured para-
types: 117189e,f.

Horizon and locality.—Sevier formation in Tennessee: Above the old marble
quarry 4 mile southeast of Hambright Mine, 8 miles south of Cleveland ; 1.3 miles
south of the center of Athens, Athens (T.V.A. 125-NE) Quadrangle.

Discussion.—This species is characterized by its strong costae and the great
depth and angularity of the sulcus. It is similar to S, acutirostra but differs in
having the pedicle fold composed of 5 costae rather than 3, in having a deeper
sulcus, and a less rounded brachial valve.

666 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

SPHENOTRETA SULCATA Cooper, new species
Plate 124, C, figures 18-23

Shell small, triangular in outline and with the maximum width between the
middle and the anterior margin; apical angle 70-80°. Anterolateral margins
fairly narrowly rounded; anterior margin truncated. Anterior commissure mod-
erately deeply sulcate in the young but nearly rectimarginate in adults. Costate;
costae narrowly rounded and closely crowded, 18 or 19 on an adult.

Pedicle valve deeper than the brachial valve and moderately convex in lateral
profile and with maximum convexity in the anterior half; anterior profile strongly
convex, with the greatest convexity in the middle. Umbonal region flattened.
Median region swollen, the swelling forming a narrowly elevated region in the
posterior half; front third somewhat flattened and bent in the direction of the
brachial valve; flanks gently convex and with steep lateral slopes. Foramen
elongate-oval; dental plates short.

Brachial valve more broadly oval than the pedicle valve, less deep and less
convex than the pedicle valve. Anterior profile broadly and moderately convex
but with median region concave. Umbo sulcate ; sulcus moderately deep through-
out the valve length. Flanks moderately swollen and with precipitous lateral
slopes.

Measurements in mm.—Holotype, length 3.6, brachial length 3.1, midwidth
3.0, greatest width 3.1, thickness 1.4.

Types.—Holotype: 117190a; figured paratype: 117190b; unfigured paratypes:
117190c,d.

Horizon and locality—McLish formation (bed 45) in Oklahoma: On West
Spring Creek, sec. 6, T. 2 S., R. 1 W., Murray County.

Discussion.—This species is characterized by its numerous closely spaced and
narrowly rounded costae, a moderately deep sulcus, and oval outline. The species
is closest to S. acutirostris (Hall) but differs in having a shallower sulcus, more
closely spaced costae, and broader outlines. It differs in these same respects
from S. cuneata.

DORYTRETA Cooper, new genus
(Greek dory, spear; tretos, opening)

Similar to Sphenotreta externally but with the sulcus reverting to a fold an-
teriorly. Foramen elongate oval and with margin thickened; deltidial plates
small, triangular.

Pedicle interior with short divergent dental plates. Brachial interior with
small triangular socket plates divided by a wide space; crura short, bent abruptly
toward the pedicle valve.

Genotype.—Dorytreta bella Cooper, new species.

Discussion.—This genus strongly resembles Hallina, but no trace of a spire
was seen in nearly a dozen specimens prepared to show the interior. Inasmuch
as the interiors are filled by translucent calcite, a loop if present should have been
detected. The genus resembles Sphenotreta but differs in not having the deep

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 667

sulcation characteristic of that genus. The brachial valve is sulcate, but the
costae in the sulcus rise anteriorly to form a fairly prominent fold. These level
off the sulcus and flanks at the front. Inside the brachial valve the parts of the
hinge plate are short and delicate but the crura are rather shorter and stouter
than those of Sphenotreta. Furthermore, the crura extend more directly toward
the pedicle valve rather than obliquely forward as they do in Sphenotreta.

Dorytreta reversa is placed in this genus with reservations. It is more strongly
costate, and the inversion of the sulcus and fold are so exaggerated that some
other category may ultimately be required for it.

DORYTRETA BELLA Cooper, new species
Plate 124, G, figures 39-43

Shell small, triangular in outline, widest just anterior to the middle; sides
forming an angle of 70°-80°; posterolateral margins gently rounded; anterior
margin subtruncate. Anterior commissure sulcate in the young, uniplicate in
the adult. Surface costate, 16 to 17 costae on an adult.

Pedicle valve deeper than the brachial one, moderately convex in lateral pro-
file and with the greatest convexity at about the middle. Anterior profile mod-
erately and broadly convex. Umbonal region moderately and narrowly convex;
median region swollen; median costa more prominent than its fellows on the
umbo and median parts; depressed anteriorly with the two on each side of it to
form a short and shallow sulcus. Flanks flattened and with moderately steep
slopes.

Brachial valve moderately convex in lateral profile, greatest depth slightly
anterior to the middle; anterior profile broadly convex but narrowly depressed
medially by the sulcus. Umbonal region somewhat flattened. Median region
moderately swollen. Sulcus narrow, deepening to middle of valve where it is
deepest but rising and becoming a low fold anteriorly. Fold composed of 4
costae, the center 2 depressed slightly below the outer 2. Flanks moderately
swollen and with steep sides.

Measurements in mm.—

Brachial
Length length Width Thickness
Holotype) |. wri teiens Sua Ahem. 3P. 6. 3.8 3.3 3.2 1.9
Paratype: dsc. tsisadace: ald. awe 4.9 4.4 4.4 2.1

Types—Holotype: 117191a; unfigured paratype: 117191b.

Horizon and locality —McLish formation (upper part) in Oklahoma: From
a roadside ditch in NW3 sec. 18, T. 2 N., R. 5 E., Pontotoc County.

Discussion.—This species is larger, wider, and more numerously costate than
the Tennessee species D. ovata.

DORYTRETA OVATA Cooper, new species
Plate 124, A, figures 1-13

Shell small, elongate ovate in outline with the widest part at about the middle;
sides rounded ; anterior margin somewhat truncate; widest at the middle; apical

668 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

angle 80°. Anterior commissure sulcate. Pedicle valve deeper than the brachial
one. Costate; costae numbering Io or II.

Pedicle valve evenly and moderately convex in lateral profile, broadly convex
in anterior profile and with the highest point at the middle to form a subcarinate
profile. Umbo not swollen; median costa more elevated than the others and form-
ing a ridge from umbo to front margin; costa on each side of umbo slightly ele-
vated so that the 3 costae form a fold. Flanks flattened and with steep slopes.

Brachial valve gently convex in lateral profile and concave in anterior profile.
Sulcus originating on the umbo and extending to the anterior margin; sulcus
occupied by 2 costae which rise anteriorly to form an indistinct fold within the
sulcus. Flanks moderately swollen.

Measurements in mm.—Holotype, length 2.7, brachial length 2.4, width 2.0,
thickness 1.1.

Types—Holotype: 117192; figured paratypes: 117193a-c; unfigured para-
types: 117193d-f.

Horizon and locality—Lenoir formation in Tennessee: On the south side of
the cemetery at Friends Church, north corner of Friendsville, Concord (T.V.A.
138-SW) Quadrangle; Indian Creek, 14 miles south of Bluff City, Bluff City
(T.V.A. 198-NE) Quadrangle.

Discussion.—This species is characterized by its small size and few costae. It
is most like Dorytreta bella but is smaller and less numerously costate.

The holotype is not a fully grown specimen because it has not attained maxi-
mum thickness or length. All the other specimens besides the figured ones are
imperfect. The longest one is about 3.1 mm. in length, and the maximum thick-
ness observed is 1.7 mm.

DORYTRETA ? REVERSA Cooper, new species
Plate 124, J, figures 55-61

Shell small, elongate oval in outline, biconvex but with the pedicle valve
slightly deeper than the brachial valve; sides gently rounded; anterior margin
subnasute; anterior commissure intraplicate; surface marked by Io angular
costae, 2 in the sulcus, 3 on the fold, and 3 or 4 on the flanks.

Pedicle valve moderately convex and with the posterior and anterior regions
more rounded than the median area. Anterior profile broadly convex. Umbonal
region somewhat flattened. Fold originating about 2 mm. anterior to the beak,
consisting of 3 costae, the outer 2 strongly elevated but the median one depressed
in a deep and narrow sulcus in the fold. Flanks flattened and depressed below
the fold and with steep lateral slopes. Beak moderately incurved ; foramen small.

Brachial valve moderately convex in lateral profile but with a distinct bulge be-
tween the umbo and the middle. Gently but broadly convex in anterior profile.
Sulcus originating at the umbo, shallow and narrow but widening and deepen-
ing anteriorly to occupy about three-fourths the width at the front margin. Sul-
cus with 2 costae appearing I mm. anterior to the beak, these costae strengthen-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 669

ing and becoming elevated anteriorly to form a prominent but narrow fold in the
sulcus. Flanks somewhat swollen and with precipitous sides.

Measurements in mm.—Holotype, length 4.9, brachial length 4.4, width 3.9,
thickness 2.4.

Type.—Holotype: 117194.

Horizon and locality.—Lincolnshire formation (Hogskin member) in Tennes-
see: On the road to Washburn 2 mile east-northeast of Red Hill, 4 miles west-
southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle.

Discussion.—The strong costae, fairly large size, and strong inversion of fold
and sulcus set this species apart from the other members of this genus.

Family ORTHORHYNCHULIDAE Cooper, new family

Pedicle valve with small interarea; brachial valve with concave crural bases
and large cardinal process.

Genus ORTHORHYNCHULA Hall and Clarke, 1893
Orthorhynchula Hatt and CuiarKE, Pal. New York, vol. 8, pt. 2, p. 181, 1893.

ORTHORHYNCHULA LINNEYI (James)
Plate 128, F, figures 32-36

Specimens showing the exterior and interior of this genus are introduced for
comparison with Drepanorhyncha and other rhynchonellids described herein.
Figured specimens.—87042a, 111352.

Superfamily Atrypacea Schuchert, 1929
Family ATRYPIDAE Gill, 1871

Spiriferacea with widely divergent crura continuous with the primary lamellae
and with the spiral cones between them.

Subfamily ZycosPprRINAE Waagen, 1883

Jugum simple, directed either anteriorly or posteriorly and with the spiralia
having the apices directed medially.

Genus ZYGOSPIRA Hall, 1862

Zygospira HAtt, 15th Rep. New York State Cab. Nat. Hist., p. 154, 1862—Hatt and
CLARKE, Pal. New York, vol. 8, pt. 2, p. 154, 1893.

This is a long-ranging genus which appears chiefly in the upper part of the
tier of rocks under consideration in this monograph. In New York and eastern
Canada Zygospira is reported earliest in rocks of Lowville age, but it is not
abundant at this level. In the middle of the overlying Trenton the genus becomes
abundant.

In the Southern Appalachians Zygospira appears in abundance in the Witten
formation and is common or abundant at various levels in the superjacent Ordo-

670 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

vician. In the Central Basin of Tennessee it is abundant in the Lebanon and
Carters formations. It has not yet been seen in the Simpson group.

From the foregoing it is evident that Zygospira has a Wilderness or Trenton
age. Rocks in Pennsylvania assigned to the “Chazyan” or “Stones River” and
containing Zygospira are almost certainly incorrectly dated.

ZYGOSPIRA CIRCULARIS Cooper, new species
Plate 141, C, figures 18-21; plate 142, B, figures 6-10; plate 142, D, figure 16

Shell of about medium size for the genus, nearly circular in outline, without
pronounced shoulders ; beak obtuse, forming an angle of 110° ; sides and anterior
margin rounded. Anterior commissure gently and broadly sulcate. Fold and
sulcus not well developed. Costae numbering 22, narrowly rounded and having
a width about equal to that of the interspaces.

Pedicle valve strongly convex in lateral profile with the convexity slightly
greater in the posterior half. Anterior profile narrowly convex. Umbo narrowly
convex; median region somewhat narrowly swollen to form an indistinct fold ;
flanks slightly concave and with steep slopes to the margins.

Brachial valve with about half the depth of the pedicle valve, moderately and
evenly convex in lateral profile, broadly and gently convex in anterior profile;
umbonal region slightly convex ; sulcus indistinct ; flanks somewhat swollen and
with moderately steep slopes to the cardinal extremities. Median costa of the
brachial valve enlarged and sunk slightly below the level of those surrounding it.

Measurements in mm.—Holotype, length 5.9, brachial length 5.3, width 5.6,
thickness 3.7.

Types.—Holotype: 111374a; figured paratypes: 111385, 117259; unfigured
paratype: 111374.

Horizon and locality—Carters formation in Tennessee: Near Franklin,
Franklin (15’) Quadrangle; on Tennessee Highway 58, 1 mile south of Wood-
bury, Woodbury (15’) Quadrangle; east side of U. S. Highway 70S, 4.2 miles
southeast of Nashville; north side U. S. Highway 70S, east of Hill Branch,
1 mile east of Woodbury, Woodbury (15’) Quadrangle; north side of U. S.
Highway 70S, 0.8 mile east of Readyville, Cannon County.

Top of Lebanon formation: In quarry on U. S. Highway 41, 11.7 miles south-
east of Murfreesboro, Rutherford County.

Discussion.—In the possession of an enlarged median rib and corresponding
median depression on the pedicle valve this species resembles Z. variabilis Fen-
ton and Fenton but differs in its more rounded outline and indistinctness of the
fold and sulcus.

ZYGOSPIRA ELONGATA Cooper, new species
Plate 268, G, figures 29-32

Shell of about medium size for the genus, longer than wide, with a subpen-
tagonal outline. Beak obtuse; posterior margins short, connecting the beak with
narrowly rounded shoulders and gently rounded lateral margins. Anterior mar-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 671

gin narrow and nearly straight. Anterior commissure narrowly sulcate. Maxi-
mum width at about the middle. Surface costate, about 27 costae in all, 5 to 7
costae occupying the sulcus.

Pedicle valve deeper than the brachial valve, fairly strongly convex in lateral
profile and with the greatest convexity at about the middle; fold originating at
the umbo, narrowly rounded posteriorly but flattened near the anterior margin ;
sides strongly concave and with steep slopes to the extremities.

Brachial valve moderately and evenly convex in lateral profile and with the
maximum convexity located slightly posterior to the middle. Sulcus originating
at the umbo, widening and deepening anteriorly to occupy about half the width
at the front. Sides bounding sulcus moderately convex; flanks gently convex
and with moderate slopes to the margins.

Measurements in mm.—

Brachial
Length length Width Thickness
EAGIOLY Py rid s date iSshobas . tatty. ¢. 5.6 5.4 5.2 3.0
Ar ALV HEBEL SZEO), aoe e ae po cans 6.4 5.9 5.0 3.4

Types.—Holotype: 111375a; unfigured paratypes: 111375b-1.

Horizon and locality——Lebanon formation in Tennessee: Readyville, Cannon
County.

Discussion —This species resembles Z. lebanonensis in its form but differs in
the possession of more numerous costae, proportionately longer valves, and more
costae in the fold and on the sulcus.

ZYGOSPIRA LEBANONENSIS Cooper, new species
Plate 142, C, figures 11-15

Zygospira saffordi Winchell and Schuchert, Hatt and CLarke, Pal. New York, vol. 8, pt. 2,
pl. 83, figs. 36-38, 1893.

Shell of about usual size for the genus, subcircular to subpentagonal in outline ;
length and width about equal ; posterior margins straight forming an obtuse angle
of 110° with the beak; sides rounded; front margin somewhat truncated to
gently rounded. Surface costate, costae numbering 18 to 23 with 5 occupying
the sulcus and 4 on the fold.

Pedicle valve moderately and evenly curved in lateral profile with the greatest
curvature at about the middle ; umbo somewhat carinated ; fold strong, extending
from the umbo to the front margin, formed of 4 costae about the same level and
2 additional ones on the slope of the fold; flanks moderately concave and with
steep slopes to the margins. Beak suberect.

Brachial valve slightly less deep than the pedicle valve, moderately and evenly
convex in lateral profile with the greatest convexity at about the center; sulcus
originating just anterior to the umbo which is slightly convex, deepening and
widening anteriorly where it occupies a little more than half the valve width.
The 3 inner costae of the sulcus are depressed below the outer 2, which in turn
are slightly depressed below the costae forming the margin of the sulcus. Flanks
slightly convex and with moderate slopes to the margins.

672 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—Holotype, length 4.5, brachial length 4.1, width 4.5,
thickness 2.5.

Types.—Holotype: 111377a; unfigured paratypes: 111377b-f.

Horizon and locality—Lebanon formation in Tennessee: At Shelbyville, Bed-
ford County ; Columbia, Maury County; 3 miles east of Murfreesboro; on U. S.
Highway 70S, # mile east of Readyville, Cannon County.

Moccasin formation in Tennessee: 3 mile east of Fleanor Mill, Powell Station
(T.V.A. 137-SE) Quadrangle.

Camp Nelson formation in Kentucky: At High Bridge, Harrodsburg (30’)
Quadrangle.

Barnhart formation in Missouri: # mile north of Riverside, Jefferson County.

ZYGOSPIRA ? MATUTINA Cooper, new species
Plate 141, B, figures 13-17

Shell small, subrhomboidal in outline; greatest width at the middle where
prominent shoulders are formed by the union of the posterolateral and antero-
lateral margins; apical angle about 80°. Anterior commissure strongly and
broadly sulcate ; surface costellate, costellae subdued and delicate, extending from
beak to anterior margin.

Pedicle valve gently convex in lateral profile; narrowly convex in the median
region in anterior profile and with long, flat, only moderately steep slopes. Beak
long; umbo narrowly convex; median region narrowly convex; anterior region
somewhat narrowly folded, and fold moderately elevated and with moderately
steep slopes.

Brachial valve gently convex in lateral profile, just perceptibly convex in an-
terior profile and with a slight depression in the median region. Umbo narrowly
sulcate, the sulcus deepening and widening to the anterior margin where it occu-
pies more than half the width. Flanks gently convex. Interior unknown.

Measurements in mm.—Holotype, length 2.4, brachial length 2.2, width 2.3,
thickness 0.9.

Type.—Holotype: 117261.

Horizon and locality.—Little Oak formation in Alabama: In the hill east of
Leeds, Leeds (15’) Quadrangle.

Discussion—The interior of this interesting little shell is unknown; it was
placed in Zygospira because its external form and folding are the same as in
that genus and its costellae cover the entire surface. In this latter respect it is
unlike Protozyga. The fine and indistinct costellae differentiate this species from
any known Zygospira.

ZYGOSPIRA MEDIOCOSTELLATA Cooper, new species
Plate 143, D, figures 13-18
Sheil of about usual size for the genus, slightly longer than wide; longitudi-

nally oval in outline; sides rounded; beak forming an angle of 90°. Anterior
margin emarginate. Maximum width slightly anterior to the middle. Anterior

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 673

commissure strongly sulcate. Surface marked by about 18 or 19 strong costae,
5 in the sulcus and 6 on the fold.

Pedicle valve strongly convex in lateral profile; greatest convexity at or
slightly anterior to the middle; anterior profile narrowly convex and with gently
convex, steeply sloping sides. Umbo narrowly swollen; median region narrowly
swollen to form a prominent fold which is not clearly demarcated from the flanks.
Fold marked by a median striation wider and deeper than the others; flanks
gently swollen. Beak long and incurved.

Brachial valve gently convex in lateral profile but with the posterior half
somewhat flattened and the anterior half moderately convex. Anterior profile
broadly sulcate; sulcus broad and shallow, its middle marked by a costa stronger,
wider, and more elevated than the surrounding ones, which corresponds to the
median striation of the fold of the pedicle valve. Flanks narrowly rounded.

Measurements in mm.—Holotype, length 5.0, brachial length 4.5, width 4.3,
thickness 2.6.

Types.—Holotype: 117260a; unfigured paratype: 117260b.

Horizon and locality.—Sevier formation in Tennessee: In wagon road just
northwest of the divide, 14 miles S. 60° W. of Bulls Gap, Mohawk (T.V.A.
172-NE) Quadrangle.

Discussion.—This species is most suggestive of Z. lebanonensis but important
differences exist. The sulcus of Z. mediocostellata is longer, deeper and wider
than that of the Lebanon species, and the widest part is posterior to the middle
rather than anterior to the middle as in Z. lebanonensis, The flanks of the latter
shell are more swollen, and the median costella and corresponding striation are
less prominent.

ZYGOSPIRA RECURVIROSTRIS (Hall)

Plate 142, H, figures 34-38

Figures of this widely misidentified species are given for comparison with the
Appalachian and other species which are mostly older stratigraphically.

Figured specimen.—1 11380.

Horizon and locality.—Trenton formation in New York: At Martinsburg,
Port Leyden (15’) Quadrangle.

ZYGOSPIRA VARIABILIS Fenton and Fenton
Plate 142, E, figures 17-25
Zygospira variabilis FENTON and Fenton, Proc. Iowa Acad. Sci. for 1922, vol. 20, p. 75,
pl. 2, figs. 7-9, 1924.

Types.—Figured hypotypes: 111387a-c,e.

Horizon and locality.—Plattin group (Macy formation-Zell member) in Mis-
souri: South Beckett Hill, Weingarten (15’) Quadrangle.

Discussion.—A silicified specimen in the National Museum collections shows
the descending lamellae of the spire and the transverse ribbon in the same posi-
tion as Hall and Clarke describe it for Z. modesta and some forms of Z. recurvi-
rostra.

674 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ZYGOSPIRA sp. 1
Plate 186, B, figures 9, 10

Shell of about medium size for the genus, longer than wide, with an elongate
oval outline ; surface costellate, marked by about 24 narrowly rounded costellae
separated by spaces about equal in width to the width of the costellae.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity near the middle; anterior profile narrowly rounded and with long con-
cave lateral slopes. Umbonal and median regions narrowly swollen. Fold con-
spicuous but not clearly demarcated from the flanks. Fold marked in center by
a stria wider than the others.

Brachial valve gently convex in lateral profile; anterior profile sulcate; sul-
cus wide and deep, occupied by 9 costellae, the median one of which is larger
than the others and corresponds to the wide striation on the fold of the pedicle
valve. Flanks narrowly rounded and inflated.

Measurements in mm.—

Brachial
Length length Width Thickness
Hypotype (pedicle valve 117262a)... 4.2 rd aur 1.0 ?
- (brachial valve 117262b).. ? 3.4 3.3 0.6 ?

Figured specimens.—117262a,b.

Horizon and locality—Gray granular limestone lenses in the Sevier formation
in Tennessee: On the hill slope on the west side of the church in Guthrie Gap,
Bulls Gap (T.V.A. 171-SE) Quadrangle.

Genus PROTOZYGA Hall and Clarke, 1893
Protozyga Haut and CLARKE, Pal. New York, vol. 8, pt. 2, pp. 149-151, 1893.

Usually small to minute, subcircular to oval in outline, biconvex, with the
pedicle valve generally the deeper. Pedicle valve with more or less pronounced
fold usually flattened or depressed longitudinally by a narrow sulcus. Brachial
valve sulcate and with the sulcus usually occupied by a more or less prominent
fold corresponding to the median depression of the fold on the pedicle valve.
Flanks smooth or paucicostate. Beak usually incurved, foramen elongate-oval
surrounded anteriorly and laterally by deltidial plates. Shell structure impunctate.

Pedicle interior with small teeth buttressed by well-developed dental plates
forming a deep delthyrial cavity. Muscle field heart-shaped.

Brachial interior with zygospiroid hinge plate consisting of narrow, triangu-
lar socket plates to which the crura are attached. A low median ridge divides
the adductor scars but does not extend posteriorly to the hinge plate. Crura
very short, terminating in crural processes ; descending lamellae long, diverging
laterally but converging toward their anterior ends. Spire variable, consisting of
part of a volution to nearly a whole volution. The descending branches are united
by a stout jugum directed more or less posterodorsally.

Genotype.—Atrypa exigua Hall, Pal. New York, vol. 1, p. 141, pl. 33, fig. 6,
1847.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 675

Discussion.—This genus is characterized by its small size, convex valves which
are smooth or sparsely costated, and the nature of the interior. The pedicle valve
is provided with strong dental lamellae and fairly large teeth, but the chief generic
characters appear in the brachial valve. The hinge plate is small and divided,
each half forming a small triangular socket or crural plate to which the posterior
ends of the crura are attached. The latter are short lamellae terminating in more
or less well defined crural processes. The descending lamellae bow outward but
then curve inward to the jugum which unites them. The spire itself consists of
a varying part of a single volution. The jugum is a stout band and is generally
in the form of a more or less pronounced U with the convex base directed pos-
teriorly and toward the brachial valve.

The brachidium of this genus is identical with that of immature Zygospira,
and the genus was put in the synonymy of that common form. Despite the inter-
nal similarities between the two, the exterior characters of Protozyga are suffi-
ciently distinct to separate it from Zygospira. Moreover, Protozyga precedes
Zygospira in its appearance in the geological column and is undoubtedly ancestral
to it.

The type specimens of Atrypa exigua Hall on which the name Protozyga is
based are preserved in the American Museum of Natural History, No. 714/1,2.
The lot now consists of 5 specimens, but the original lot, to judge by Hall’s
figures in Paleontology of New York, vol. 1, consisted of 3 specimens. The
type catalog of the American Museum of Natural History, 1898, lists 4 speci-
mens only.

Of the 5 specimens now in the type lot, 1 is a large form, larger than any
member of the genus hitherto described, and is evidently the specimen referred
to in Whitfield’s catalog as coming from Watertown, N. Y. This specimen is
figured in Paleontology of New York, vol. 8, pt. 2, pl. 54, figs. 47, 48, and in the
Handbook of brachiopods, but it is not figured in the original lot in the Paleon-
tology of New York, vol. 1.

A second specimen consists of a small sliver of calcite containing a fairly well
preserved loop. This specimen is not referred to in the catalog. The 3 remain-
ing specimens are well-preserved individuals, 2 of which are alike, but the third,
which is squarer and with other differentiating features, differs quite distinctly
from the other 2.

In attempting to select one of these specimens to serve as type for the species
and incidentally for the genus, too, as the name Protozyga is based on the species
in question, critical examination of all 5 specimens was undertaken. The calcite
sliver can be rejected as a possible holotype because it is impossible to link it
with any external form, and the writer was unable to find a jugum in it. The
specimen, therefore, does not possess one of the chief defined features of the
genus Hall and Clarke were describing. The spire enclosed by the calcite seems
to have the features of the brachidium of Cyclospira.

The largest specimen which is well preserved would be an ideal type specimen
if it conformed to the description and if its internal characters could be demon-
strated. Unfortunately, this specimen is shrouded by difficulties. It measures

676 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

74mm. wide, 65 mm. long, and 44 mm. thick. The pedicle valve bears a marked
fold that extends from the umbo to the anterior margin. The brachial valve is
deeply sulcate but is without a fold in the sulcus as is usual in the zygospiroids
under study. The lateral margins are narrowly convex and the anterior margin
is excavated medially. The beak is broken off so that the foramen and delthyrial
region are not available, although the figures of the specimen reproduced by
Hall and Clarke show a small circular foramen which is totally unlike that of
any of the zygospiroids in question. The most surprising feature of this speci-
men is its finely punctate shell. Internally, little can be seen, but the beak is
broken off in such a way that dental plates would be revealed if the specimen
had had such structures. The form of the specimen, its lack of dental plates, and
its punctate shell, as well as its fresh appearance, indicate a specimen far younger
in age than any of the zygospiroid stock. The ensemble of characters suggests
one of the terebratuloids with fold on the pedicle valve of the Mesozoic such as
Nucleata, Pygope. How such a specimen could be confused with Airypa exigua
from New York can only be conjectured, but its equivocal nature excludes it as
a holotype for the species. The remaining three specimens are available for
choosing a lectotype. Of these three, the one from Watertown, New York, is
rejected as not belonging in the original lot. Of the remaining two, one is im-
mature and without costae, the other is imperfect, having a small sliver out of
one side. This specimen is adult in size and exhibits the costae faintly. It is
therefore selected as type of the species.

Protozyga is a fairly common genus in the rocks covered by this monograph.
It occurs first in the Crown Point limestone from which a single specimen is
known. This specimen is an elongate form with prominent attenuate beak and
a few obscure costae on the margins. The interior of this specimen is unknown,
but it is the earliest brachiopod like Protozyga to be seen.

In the Southern Appalachians the genus appears first in the Whistle Creek
formation, but the three specimens taken do not yield information on the interior.
These specimens are not folded like the later ones, which might be a natural
characteristic of one of the earliest members of the genus.

Specimens are locally abundant in the Ward Cove limestone and the Benbolt
and Wardell formations. In these the tendency to folding is more highly de-
veloped, but this reaches its maximum development in Trenton species. The
Rockland formation yields P. exigua which is strongly folded and fairly strongly
costate. The folding reaches its maximum in P. profunda.

PROTOZYGA COSTATA Cooper, new species
Plate 142, A, figures 1-5

Small, oval in outline with the length greater than the width; widest at the
middle ; valves unequal, the pedicle valve having a greater depth than the brachial
valve; apical angle 100° ; sides rounded; anterior margin rounded to subnasute ;
anterior commissure faintly sulcate ; surface paucicostate, 2 costae in the sulcus
(rarely 3), 3 costae on the fold (rarely 4), and 4 costae on the flanks ; costae
usually not extending for more than two-thirds the length from the margin.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 677

Pedicle valve strongly convex in lateral profile with the maximum convexity
in the posterior half; anterior commissure somewhat narrowly convex and with
long, steep lateral slopes. Umbo narrowly convex; median region narrowly in-
flated; anterior third marked by a low, poorly defined fold.

Brachial valve shallow, gently convex in lateral profile; anterior profile barely
concave to broadly and gently convex; umbonal region broadly and gently con-
vex; sulcus narrow and shallow, originating near the middle and almost com-
pletely filled by 2 costae. Sulcus shallow throughout its length. Flanks gently
inflated. Spire as described for the genus.

Measurements in mm.—Holotype, length 4.5, width 3.9, thickness 2.2.

Types.—Holotype: 117239c; unfigured paratypes: 117239a,b.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: In the road cut on Oklahoma Highway 18, 1.8 miles south of Sulphur,
Murray County ; Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray County ; on the
north side of Falls Creek along the road to the Baptist Camp, NE4SE# sec. 32,
T.1S., R.2E., Murray County; from deep well at 3,240 to 3,244 feet in Mid-
continent Petroleum Corporation well, sec. 22, T. 4 N., R. 3 E., Pottawatomie
County.

Discussion—This species is characterized by its strong costae and elongate
form. In the latter respect it is like P. elongata, but that species is not so strongly
costate. It differs from other Oklahoma species and the known species outside
of Oklahoma by the moderate development of the fold and sulcus and the strong
costation of these features.

PROTOZYGA ELONGATA Cooper, new species
Plate 140, E, figures 27-37; plate 143,I, figures 41-46

Shell small, elongate oval in outline with the greatest width at about the
middle; sides gently rounded; anterior margin truncated. Surface marked by
fine growth lines and the flanks by 2 to 4 obscure costae.

Pedicle valve fairly strongly convex and with the greatest convexity at about
the middle; beak elongated; umbo narrowly rounded and extended anteriorly
as a prominent fold to the anterior quarter where a shallow sulcus divides the
fold into 2 narrowly rounded costae. Flanks concave and steep sided. Marginal
fold between umbo and shoulder fairly strong.

Brachial valve with less depth and less convexity than the pedicle valve and
with the maximum convexity at about the middle. Umbonal and median regions
somewhat swollen. Fold narrow, originating at about two-thirds the length from
the beak of the brachial valve. Flanks convex but with moderate slopes to the
extremities.

Measurements in mm.—Holotype, length 3.1, width 2.3, thickness 1.7.

Types.—Holotype: 117241a; figured paratypes: 117241b,c, 111408a,b.

Horizon and locality—Bromide formation (Mountain Lake member—Dole-
roides zone=bryozoan zone) in Oklahoma: Along the old road up the hill
northwest of the old Galbraith Hotel, sec. 32, T. 1 S., R. 8 E., Johnston County ;

678 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ditch on east side of road 2,300 feet south and 2,000 feet west of the northeast
corner of sec. 36, T. 1 S., R. 7 E., 1 mile west of Dolese Brothers Crusher, Bro-
mide, Johnston County; zone 36, on Oklahoma Highway 99, SW4NW4SW4
sec. 12, T. 1 N., R. 6 E., Pontotoc County; Mimella zone, Baptist grounds at
Falls Creek, SWANW4SW3 sec. 33, T. 1 S., R. 2 E., Murray County; bed 2,
west of Nebo store, sec. 22, T. 2 S., R. 3 E., Murray County; road cut on east
side of section line road, 1,300 feet south of the northwest corner of sec. 23,
T.1S., R. 3 E., opposite road to abandoned town of Gilsonite, Murray County ;
50 to 75 feet below ford of Hickory Creek, 2 miles west of Overbrook, Carter
County ; 2 miles northeast of Springer, McLish Ranch, sec. 24, T. 1 S., R.7 E.,
Johnston County.

Discussion.—This species is characterized by its elongate form and the elonga-
tion of the beak which is not strongly incurved. In this respect it resembles
P. superba, but that species is larger, wider, and more deeply sulcate than
P. elongata. Confusion with P. loeblichi is not likely to occur because that species
is wider and with a much less elongated beak.

Protozyga elongata is a variable species as are all members of this genus. The
variation takes form in more convex or somewhat wider individuals with a less
elongated beak. If found by themselves, some of these might be assigned to
other species.

PROTOZYGA EXIGUA (Hall)
Plate 119, D, figures 9-14; plate 140, F, figures 38-42; plate 142, G, figures 29-33

Atrypa exigua (HALL), Pal. New York, vol. 1, p. 141, pl. 33, fig. 6, 1847—-EmmMons, Amer.
geology, vol. 1, pt. 2, p. 190, pl. 10, fig. 6, 1855.—LresLey, Pennsylvania Geol. Surv.,
Rep. P. 4, p. 55, 1880.

Genus ? exigua HALL, 12th Rep. New York State Cab. Nat. Hist., p. 66, 1850.

Protozyga exigua (Hall) Hai and CLarKe, Pal. New York, vol. 8, pt. 2, p. 149, figs. 137,
138 (not pl. 54, figs. 47, 48), 1893.

Zygospira exigua (Hall) ScHucuert, U. S. Geol. Surv. Bull. 87, p. 463, 1897.

Large for the genus, pentagonal in outline; strongly inequivalve; postero-
lateral margins nearly straight, forming an apical angle of about 100°. Greatest
width at or near the middle. Sides narrowly rounded. Anterior margin broadly
rounded. Anterior commissure broadly sulcate. Surface paucicostate, about 5
obscure costae on the flanks, fold and sulcus variably costate.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity at about the middle; anterior profile narrowly convex in the middle and
with depressed and concave sides. Umbonal region narrowly convex, continued
anteriorly as a strong, steep-sided fold which is flattened on top and often with a
slight depression. Fold with 2 or 3 obscure costae. Flanks concave but with
lateral areas deflected slightly in the direction of the pedicle valve.

Brachial valve moderately convex in lateral profile; maximum convexity at
about the middle; anterior profile gently and broadly convex but with a narrow
and shallow median depression. Umbo sulcate; sulcus shallow throughout its
length from umbo to anterior margin; fold in sulcus originating anterior to

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 679

middle when present, usually low and obscure but more frequently not developed.
Flanks inflated and with steep lateral slopes. Median ridge moderately strongly
developed.

Measurements in mm.—

Length Width Thickness
Fiypotype’ (11724208) 5. 2. POR Pa 6.4 6.6 4.6
is Crizeaeb®.). tonihh. iG. os oe 6.5 6.2 4.2
¥ Crag2age iti oi-saseeot Ie eee 6.6 6.4 4.3
f CUA, «at Hcy Sees erent uaa 6.7 6.0 4.2
- CRASS Gs ssh anciia ss Gate eh Ree 5.8 6.0 a7

Types—Lectotype: A.M.N.H. 714/1,2a, large imperfect specimen ; paratype:
714/1,2b, small perfect specimen; figured hypotype: 117242e; measured hypo-
types: 117242a-c, 1232098a,b.

Horizon and locality.—Rockland formation (Napanee member) in New York:
Just west of the bridge over Mill Creek in the city of Lowville, Lowville (15’)
Quadrangle ; on the west side of New York Highway 12 at its crossing of Sugar
River, about 4 miles south of Port Leyden, Port Leyden (15’) Quadrangle.

Discussion.—This species is recognized by its large size, shallow sulcus, and
moderately strong costae on the margins. It resembles P. profwnda Cooper but
differs in having a less deep sulcus and a less narrow fold. It also suggests
P. nicolleti but differs in not having a strong sulcus in the fold of the pedicle
valve and in not having the strong development of the fold within the sulcus,
which is so prominent in the Minnesota species. It is also close to P. superba, but
that species has a short but prominent fold in its sulcus. The Missouri species
also has fuller and more convex flanks. See discussion of genus above for selec-
tion of type specimen.

PROTOZYGA LOEBLICHI Cooper, new species
Plate 140, C, figures 17-21

Shell small, subpentagonal to longitudinally elliptical in outline; beak obtuse;
sides broadly rounded; anterior margin subnasute. Surface smooth in the pos-
terior two-thirds, marked on the margins by obscure costae, I or 2 of which
appear on the flanks.

Pedicle valve evenly and gently convex in lateral profile and with the great-
est convexity located at about the middle. Beak incurved but not resting on the
umbo of the brachial valve which is gently convex ; median region inflated ; sulcus
bounded by 2 narrowly rounded costae, sulcus originating at about the middle
and extending to the anterior margin; flanks concave and with steep slopes.

Brachial valve moderately and evenly convex in lateral profile and with the
maximum curvature near the middle. Anterior profile broadly convex. Umbonal
region gently convex, median portion of valve somewhat inflated. Fold origi-
nating in the anterior third, low and narrow, flattened on top and set off by 2
oblique, shallow grooves. Flanks convex and with moderate slopes.

680 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Length Width Thickness
HiOlotype 1. ch sb sie Peas OWE sa eee: CUR e Mee 3.1 a7 r7
Paratype... ,43aeoe? beens St Pee Sees B:1 2.6 1.8

Types.—Holotype: 111412a; unfigured paratype: 111412b.

Horizon and locality—Bromide formation (Pooleville member—O-oplecia
gouldi zone) in Carter County, Okla.: At Rock Crossing of Hickory Creek,
about center sec. ‘35, T. 5 S., R. 1 E., Criner Hills.

In Murray County, Okla.: At the top of Bromide, small quarry east of road
in center NW4 sec. 11, T. 11 S., R. 3 E.; middle of bed 2, Spring Creek, sec.
17) D2 RE PWS siehtly nerth:ot the middletof sec. ‘32)-'T "2-5: Rene,
2 to 3 miles northeast of Springer; 50 feet below the Viola, 4 miles west and
2 miles south of Davis.

Discussion.—This species is suggestive of P. nicolleti and also of P. rotunda.
From the former it differs in not possessing the strong radial costae on the flanks
and in having a much broader fold in the sulcus of the brachial valve. It differs
from P. rotunda in its smaller size, less rotund profile, less circular outline, more
prominently elevated fold of the brachial valve, and the anterior third less de-
flected toward the pedicle valve. The front margin of P. loeblichi is less nasute
than that of the Tennessee species and is generally sharply truncated anteriorly.

PROTOZYGA MAGNICOSTATA Cooper, new species
Plate 140, A, figures I-9

Shell resembling P. costata but length and width nearly equal; widest at or
near the middle; sides strongly rounded; anterior margin somewhat broadly
rounded; anterior commissure faintly sulcate; surface paucicostate, 2 strong
costae marking the sulcus, 3 on the fold, and 2 or 3 on the flanks. Median costa
of fold usually depressed and corresponding with furrow between costae occupy-
ing sulcus. Costae strong.

Measurements in mm.—

Length Width Thickness
LOT QE MTG i Selivis anshtawid nin eotian statewide Taare cusses 4.0 3.9 fee
Paratyne CT EACAR Dy vas wi siechs ahaldcrasan pia ptcaie 4.1 3.9 2.0

Types——Holotype: 117245a; figured paratypes: 117245b, 118040.

Horizon and locality—Bromide formation (Mountain Lake member—30 to
34 feet below the top of bed 10) in Oklahoma: On Tulip Creek, SW4NW4NE}4
sec. 25, T. 2.S., R. 1 E., Carter County; bed 7, Spring, Creek, sec. 17, T. 2 S.,
R. 1 W., Murray County.

Discussion —This species suggests P. costata but differs in being more rotund
in outline and having stronger, more sparsely placed costae. Furthermore,
P. magnicostata differs in the arrangement of the costae on the fold of the pedicle
valve, the median one of which is sunk below the bounding, outside 2.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 681

PROTOZYGA MICROSCOPICA Cooper, new species
Plate 141, D, figures 22-24; plate 141, F, figures 33-37

Shell minute, subpentagonal in outline; sides gently rounded ; anterior margin
truncated; posterolateral margins straight, forming an apical angle of about
100°. Surface smooth, except for a short fold on the brachial valve and 2 obscure
costae on the pedicle valve.

Pedicle valve fairly strongly convex in lateral profile and with the maximum
convexity slightly posterior to the middle; anterior profile narrowly convex in
the median region but with concave lateral slopes. Umbo narrowly rounded;
median region swollen narrowly to form an indistinct fold which is marked
medially by a deep sulcus originating about one-third the length from the anterior
margin. Sulcus bounded by short, narrow costae. Flanks gently concave.

Brachial valve gently convex in lateral and anterior profiles; umbonal and
posteromedian areas swollen ; sulcus broad and shallow, originating at about one-
third the length from the anterior margin, occupied almost completely by a low,
rounded fold corresponding to the sulcus of the pedicle valve; fold separated
from the flanks by short, narrow grooves. Flanks gently inflated.

Measurements in num.— Length Width Thickness
VOLS Eyed hye a: Saini rcs «5 erste cheiaed + siaeretawn sys 3.3 2.9 2.0
PEA O Es the teh Riots oars Pens tomate eae canes ae 22 1.9 1.3

Types.—Holotype: 117243 ; figured paratype: 117244.

Horizon and locality.—Lincolnshire formation (Hogskin member) in Tennes-
see: 3 mile east-northeast of Red Hill, about 4 miles west-southwest of Thorn
Hill, Avondale (T.V.A. 162-SW) Quadrangle ; 3 miles west-southwest of Thorn
Hill, same quadrangle; Luttrell, Luttrell (T.V.A. 155-NW) Quadrangle.

Ward Cove formation in Tennessee: At Evans Ferry; in Mulberry Gap 4
miles north-northwest of Sneedville, Back Valley (T.V.A. 161-SE) Quadrangle.

Ward Cove formation in Virginia: On Virginia Highway 82, 14 miles north-
west of Lebanon, Lebanon (T.V.A. 205-NE) Quadrangle.

Elway formation in Tennessee: At Marble Bluff, 8 miles west-northwest of
Loudon, Loudon (30’) Quadrangle.

Discussion.—This species is characterized by its convex valves and the sub-
dued nature of the folding of both valves and the margins. Protozyga micro-
scopica has a less prominent beak than P. nasuta, which it resembles in contour,
and is also more prominently sulcate in the pedicle valve than that species.
Protozyga loeblichi has a less prominent fold than P. microscopica and lacks
costae on the margins. Protozyga rotunda is a larger and more robust shell which
is more strongly costate than P. microscopica.

PROTOZYGA NASUTA Cooper, new species
Plate 141, G, figures 38-41
Small for the genus, subpentagonal in outline ; lateral margins gently rounded ;

anterior margin gently rounded; anterior commissure nearly rectimarginate ;
surface smooth and without visible costae.

682 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve moderately convex in lateral profile and with the maximum con-
vexity at about the middle; anterior profile somewhat narrowed; median region
somewhat narrowed but becoming flattened and faintly depressed in the anterior
third. Beak long, narrow, incurved, Flanks faintly convex.

Brachial valve only slightly less deep than the pedicle valve, fairly strongly
convex in lateral profile and with the maximum convexity just posterior to the
middle; anterior profile broadly and moderately convex ; region just posterior to
middle strongly inflated; umbo swollen; anterior half flattened; flanks not dif-
ferentiated from the median region, gently convex but with gentle slopes.

Measurements in mm.—Holotype, length 2.8, width 2.5, thickness 1.6.

Types.—Holotype: 117246a; unfigured paratypes: 117246b-1.

Horizon and locality Whistle Creek formation in Virginia: On U. S. High-
way 60, 100 yards southeast of Whistle Creek, 2 miles northwest of Lexington,
Lexington (15’) Quadrangle.

Discussion.—This species is characterized by its long beak, lack of folding, and
absence of well-marked fold and sulcus. It differs from P. rotunda and P. micro-
scopica, which it resembles in its strong convexity, by its general lack of folding.

PROTOZYGA NICOLLETI (Winchell and Schuchert)
Plate 141, J, figures 51-57

Hallina nicolleti WINCHELL and ScHucHERT, Amer. Geol., vol. 9, p. 293, Apr. 1, 1892; Geol.

Minnesota, vol. 3, p. 474, pl. 34, figs. 59-64, 1805.

Zygospira aquila SARDESON, Minnesota Acad. Nat. Sci. Bull. 3, p. 335, pl. 4, figs. 15-18,
Apr. 9, 1892.

Z. nicollett Winchell and Schuchert, BEECHER and ScHUCHERT, Proc. Biol. Soc. Washington,
vol. 8, pt. 2, p. 71, pl. 10, fig. 23, 1893.

This is one of the largest of the known species of the genus and can be recog-
nized by its strongly incurved beak, strongly elevated fold of the pedicle valve
with narrow sulcus, strongly incurved beak, narrow brachial fold in a wide,
shallow sulcus, and the strong and numerous costae marking the flanks. A large
specimen measures 5.4 mm. in length, 5 mm. in width, and 3 mm. in thickness.

The species differs from P. rotunda by its stronger costation and more promi-
nent fold on the brachial valve. It differs from P. superba by its shallower sulcus,
less pronounced fold on the pedicle valve and stronger fold on the brachial valve,
combined with the less prominent beak.

Types.—Figured hypotypes: 24201a, 49060a.

Horizon and locality.—Platteville formation in Minnesota: At St. Charles,
Winona County; Rochester, Elmira, and NW4 sec. 10, Olmstead County; Min-
neapolis.

Platteville formation (MacGregor member): On Minnesota Highway 74,
just east of Chatfield; U. S. Highway 52, 2 to 3 miles north of Fountain, Fill-
more County.

In Illinois: 14 miles northeast of Dixon, Dixon (15’) Quadrangle.

Same formation in Wisconsin: Road cut near Dickeyville, sec. 9, T. 2 N.,

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 683

R. 2 W., Grant County; quarry on Wisconsin Highway 81, 1 mile northwest of
Ellenboro, Lancaster (30’) Quadrangle.

PROTOZYGA PROFUNDA Cooper, new species
Plate 143, A, figures 1-6

Shell large for the genus, slightly wider than long, outline pentagonal. Strongly
inequivalved ; posterolateral margins nearly straight, forming an angle of about
110°; sides narrowly rounded and with the greatest thickness at about the
middle ; anterior somewhat truncated ; anterior commissure strongly sulcate ; sur-
face paucicostate, flanks with as many as 7 more or less distinct fine costae not
reaching the beak; fold and sulcus finely but variably costate.

Pedicle valve strongly convex in lateral profile, with the maximum curvature
in the posteromedian part ; anterior profile with narrowly convex middle part and
concave flanks; umbo narrowly swollen and continued anteriorly as a steep and
narrow fold; sulcus in fold originating at about the middle, shallow and narrow.
Flanks deeply concave but with flattened sides.

Brachial valve moderately convex in lateral profile and with the maximum
convexity at about the middle ; anterior profile broadly convex but with a median,
deep sulcus; umbo sulcate, the sulcus continued anteriorly and forming a deep
and narrow trench; tongue long and narrow; flanks bounding sulcus somewhat
narrowly swollen and with steep lateral slopes. Interior as in the genus.

Measurements in mm.—Holotype, length 5.8, width 6.6, thickness 4.0.

Types.—Holotype: 117247a; unfigured paratype: 117247b.

Horizon and locality—Trenton formation in Quebec: In a quarry near
St. Francis de Salle, Montreal.

Discussion—This species differs from all others here assigned to Protozyga
by the great depth of its sulcus and the nearly complete costation of the flanks.

PROTOZYGA ROTUNDA Cooper, new species
Plate 140, B, figures 10-16; plate 140, H, figures 48-52; plate 140,I, figures 53-58

Shell small, nearly circular in outline, strongly biconvex, beak approximately
a right angle or slightly obtuse, sides strongly rounded, anterior margin pro-
truding slightly, rounded. Surface smooth or with I or 2 short, obscure costae
on the margins of the flanks near the fold or sulcus.

Pedicle valve generally deeper than the brachial valve, strongly convex and
with the greatest convexity at about the middle; beak strongly incurved and in
old specimens closely pressed down on the umbo of the brachial valve; umbonal
region gently convex in profile, narrowly convex in anterior view ; fold originat-
ing on the umbo, not strongly elevated and extending to the anterior margin.
Sulcus shallow ; appearing in the fold a short distance posterior to the anterior
margin; flanks gently convex or nearly flat in profile and with steep slopes to
the margin. Beak ridges short, not prominent.

Brachial valve moderately to strongly convex depending on age, the older
shells more rotund and deeper; anterior profile moderately convex. Umbonal

684 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

region gently swollen and the median region slightly more inflated. Sulcus shal-
low, originating about one-third the length from the anterior margin, occupied
by a low fold. Flanks moderately convex, and with moderately steep slopes to
the margins.

Interior: Spire long, with long descending branches and a wide jugum ex-
tending nearly horizontally between the descending branches at about the middle
of the valve. Hinge plates triangular, small.

Measurements in mm.—

Length Width Thickness
PROOUY DE” 5 ois Uae eas car ate nec Meena a eta te 4.9 4.7 3.4
Poratype’ (ritassa) so eee ee ee eee ee eee 4.0 ar7 27
ns (HEPA4BAI NOAA RE OLE 4.2 3.5 2.6
He CraveaBh) Diba sleeves Potendld pide 4.0 3.6 2.5

Types.—Holotype: 111433a; figured paratypes: 111435a-c, 111433b, 117248b ;
measured paratype: 117248a.

Horizon and locality—Wardell formation and Wardell part of the Dryden
formation (Hesperorthis beds) in Tennessee: 0.3 mile southwest of Little Bar-
ren Church, on old Tennessee Highway 33, 10 miles southwest of Tazewell in
Powder Springs (T.V.A. 154-SW) Quadrangle; vicinity of Lone Mountain,
Tazewell (T.V.A. 154-NE) Quadrangle; west side of the sharp loop on the
road down Flint Creek, NW4 of the center subquad., Powder Springs (T.V.A.
154-SW) Quadrangle; north of the Canyon of Gap Creek, Powell Valley, Ten-
nessee grid 790250N, 2677730E, 14 miles west of Arthur, Cumberland Gap
(T.V.A. 153-SW) Quadrangle ; 34 miles north of Ooltewah, Ooltewah (T.V.A.
112-SE) Quadrangle; Evans Ferry, 4 mile north of Indian Creek, Howard
Quarter (T.V.A. 162-NW) Quadrangle.

Wardell formation in Virginia: At Lloyd Carter’s barn, 0.8 mile northeast of
Rye Cove School, Clinchport (T.V.A. 188-NW) Quadrangle; quarry on Sta-
tion Creek, 4 mile south of U. S. Highway 58, 2 miles east of Cumberland Gap,
Wheeler (T.V.A. 153-SE) Quadrangle.

Ridley formation in Georgia: On U. S. Highway 27, 1 mile north of Rock
Spring, Nickajack Gap (T.V.A. 113-SW) Quadrangle; quarry on the west side
of the road 14 miles south-southeast of Cove Church, 5 miles south of Chicka-
mauga, Kensington (T.V.A. 106-SE) Quadrangle.

Ridley formation in Tennessee: 14 miles southeast of Hembree Mill, Se-
quatchie Valley, Pikeville Special (15’) Quadrangle.

Lebanon formation in Tennessee: On U. S. Highway 70N opposite Fairview
Service Station, 4 mile west of Rome, Smith County.

Barnhart formation in Missouri: On the old road 1 mile north of Chicago
Summer School Camp, NW1iSW3 sec. 32, T. 37 N., R. 9 E., Weingarten (15’)
Quadrangle.

Discussion.—Silicified specimens from the “Lowville” limestone of Georgia
permit description and illustration of some features of the interior. The dental
plates are well developed, flaring and extended along the side of the muscle field
for a short distance. The teeth are moderately strong and have well-developed

PART. .& CHAZYAN AND RELATED BRACHIOPODS—COOPER 685

sockets between the tooth proper and its attachment to the valve. The individual
muscle marks of this valve are not visible but the field is somewhat heart-shaped,
large, and located just anterior to the delthyrial cavity.

The hinge plate of the brachial valve is zygospiroid; divided into two oblique
socket plates, short and narrow, that are attached to the valve on the sides of
the notothyrial cavity. The adductor scars are small, and arranged on each side
of a low median ridge that does not reach posteriorly to the notothyrial cavity
and does not support the hinge plate.

This species is characterized by its globular form and fairly large size. It
differs from P. nasuta and P. microscopica in size and in having more prominent
folding and costation. It resembles P. loeblichi but is a larger shell with more
circular outline, less prominently elevated fold on the brachial valve, and the
anterior third more deflected toward the pedicle valve.

PROTOZYGA ROTUNDIFORMIS Cooper, new species

Plate 140, J, figures 59-62

Shell nearly circular in outline, slightly longer than wide; sides rounded, an-
terior margin truncated; valves subequal, the pedicle valve having the greater
depth ; paucicostate, the flanks marked by 1 or 2 obscure costae confined to the
anterior and lateral margins.

Pedicle valve moderately and evenly convex in lateral profile and with the
maximum convexity at the middle; anterior profile strongly convex and with
moderate slopes. Median region inflated ; umbonal region narrowly rounded, the
rounding continued anteriorly but indistinctly as a low fold. Fold sulcate in
anterior third, sulcus short, moderately deep, defined by a short costa on each
side. Flanks gently inflated and with moderately steep slopes to the margins.

Brachial valve moderately convex in lateral profile, maximum convexity just
posterior to the middle; anterior profile broadly but fairly strongly convex ;
median region strongly swollen; sulcus originating just anterior to the middle,
poorly defined and indistinct ; sulcus occupied by a poorly defined low fold indis-
tinct except at the margin. Flanks swollen and steep-sided.

Measurements in mm.—Holotype, length 2.9, width 2.5, thickness 2.0.

Type.—Holotype: 117249.

Horizon and locality.—Lincolnshire formation (go to 120 feet above the “Mos-
heim”) in Tennessee: On U. S. Highway 25E, 1 mile north of Indian Creek,
Howard Quarter (T.V.A. 162-NW) Quadrangle.

Discussion.—This species is characterized by its small size and globular form.
It is much smaller than P. rotunda and differs further from that species in its
more circular outline, stronger marginal costae, and the more nearly equal depth
of its valves. The stronger costation distinguishes this species from P. nasuta
and P. microscopica, both of which occur in formations near the age of that of
P. rotundiformis.

686 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PROTOZYGA SUPERBA Cooper, new species
Plate 141, L, figures 63-69

Zygospira nicolleti Winchell and Schuchert, Forrste, Bull. Sci. Lab., Denison Univ., vol. 10,
No. 3, p. 199, pl. 23, figs. 8A, 8B, 1920.

Adult fairly large for the genus, pentagonal to subcircular in outline; beak
acute to obtuse, strongly incurved; lateral margins rounded; anterior margin
narrowly rounded to subtruncate. Surface smooth except for 2 or 3 costae de-
veloped along the front margin on each side of the fold and sulcus.

Pedicle valve with nearly twice the depth of the brachial valve, strongly con-
vex in lateral profile with the greatest convexity in the posterior half in the adult ;
umbo narrowly swollen ; fold originating on the umbo and extending as a rounded
plica to the middle of the valve where a shallow depression develops in the center
of the fold and extends to the front margin; flanks nearly flat in profile and with
steep slopes to the margins.

Brachial valve evenly and moderately convex in lateral profile with the great-
est convexity at about the middle; umbonal, median region, and flanks some-
what swollen; sulcus originating on the umbo, where it is poorly defined and
shallow, becoming deeper and wider near the middle and occupying nearly half
the width at the front margin. One or two costae appearing anteriorly in the
sulcus which correspond to the sulcus in the fold of the pedicle valve ; sulcus
drawn anteriorly and toward the pedicle valve into a moderately long, squarely
truncated tongue. Flanks convex in profile and slopes to the margins moderately
steep.

Interior: Dental plates of pedicle valve well developed ; adductor muscle tracks
of brachial valve long and slender.

Measurements in mm.—

Length Width Thickness
FIOISEV DEN, 0:24 Mise Heated eR apn toad tippers 5.3 4.9 3-4
Pagatyne (CRI VARS D sn acy oxucie ae Mole Ot eat. 4.1 4.2 2.8
y CEREAS SC Me ote © ase eehebal ale ale 0 ok 4.6 4.5 2.2

Types.—Holotype: 111455a; unfigured paratypes: 111455b,c.

Horizon and locality—Auburn chert in Missouri: 4 mile east of Auburn,
Elsberry (15’) Quadrangle.

Top of Plattin group (=Barnhart formation) in Missouri: Buford Cave,
Ralls County; Yeager Farm, south edge of Ralls County; Conns Ford, Ralls
County.

Discussion——This species resembles P. nicolleti but differs in possessing a
more convex pedicle valve, fewer costae on the flanks, a deeper sulcus, and a
lesser development of the fold within the sulcus of the brachial valve. This latter
feature is the most striking difference. In the Minnesota species the fold may
originate in the sulcus posterior to the middle of the valve, but in P. superba the
fold within the sulcus occurs in the front part of the sulcus and on the tongue.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 687

PROTOZYGA TUMIDA Cooper, new species
Plate 140, G, figures 43-47; plate 141, I, figures 46-50

Shell of about medium size for the genus, length and width nearly equal ; sub-
pentagonal in outline; apical angle about 120°. Surface paucicostate, 4 or 5
obscure costae on the flanks.

Pedicle valve fairly strongly convex in lateral profile, and with the maximum
convexity at about the middle; anterior profile narrowly convex in the median
region and with steeply sloping sides. Umbonal region narrowly convex and
continued anteriorly as an indistinct fold; fold prominent in the anterior third
and marked by a deep and wide sulcus originating at about one-third the length
from the anterior margin; flanks flat to gently concave and with steep slopes.

Brachial valve shallow, gently convex in lateral profile and with the maximum
curvature slightly posterior to the middle; anterior profile gently convex to
nearly flat; umbonal and median regions swollen; sulcus originating just an-
terior to the middle, broad and shallow; sulcus occupied by a narrow, rounded
fold equal in length to about one-third the valve length. Sulci bounding fold
fairly wide and moderately deep. Flanks gently inflated and with gentle slopes.

Measurements in mm.—

Length Width Thickness
LOG VMe a cist ecrs crete <Gienoisrast= cheat Sielelstevend seokpereters 3.5 3:2 1.9
ESIC TAT OUT eee CE ORE Meee sore. 3.0 2.9 1.6

Types—Holotype: 111440; figured paratype: 111400.

Horizon and locality.—Effna formation in Virginia: At McNutt Quarry, 12
miles southwest of Bland, Burkes Garden (15’) Quadrangle; equivalent of Effna
formation 4 and 6 miles southwest of Bland, Bland County.

Discussion.—This species is characterized by its strongly pentagonal form and
the broad, shallow brachial valve. The low convexity of this valve distinguishes
the species from all the others herein described.

PROTOZYGA UNIPLICATA Cooper, new species
Plate 140, D, figures 22-26; plate 141, H, figures 42-45; plate 141, K, figures 58-62

Shell small, longer than wide, heptagonal in outline; sides broadly rounded ;
apical angle 100° ; surface smooth except for 1 or 2 obscure costae on the flanks.

Pedicle valve fairly strongly convex in lateral profile and with the maximum
convexity at about the middle; anterior profile narrowly convex but with long,
steep, flat slopes. Umbonal region narrowly inflated; median region narrowly
rounded, the rounding forming a fairly prominent but low fold at the anterior ;
fold fairly deeply but narrowly sulcate in its anterior quarter to third. Sides
steep and flat. Beak erect.

Brachial valve gently convex in lateral profile and with the greatest convexity
at the middle; anterior profile moderately rounded ; umbonal and median regions
somewhat inflated; sulcus originating at about the anterior third and occupied
by a prominent fold separated from the flanks by 2 narrow and moderately deep
depressions. Flanks swollen and steep.

688 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Length Width Thickness
Paratype: CIl72500 id vas sie eelicint oom om anes 3.4 2.8 1.8
a (a Riawba) Foye. Hieyccal vated. Belge Oe 3.6 3.0 1.7

Types—Holotype: 111416b; figured paratypes: I11414a,c, 111416a; un-
figured paratypes: 111414b, 117250a.

Horizon and locality —Benbolt formation in Virginia: At Rye Cove, Clinch-
port (T.V.A. 188-NW) Quadrangle; 0.2 mile south of the middle fork of Moc-
casin Creek, 14 miles due south of Hansonville, Hansonville (T.V.A. 205-SW)
Quadrangle; north side of U. S. Highway 19, about 1 mile due north of Belfast
Mills, Saltville (T.V.A. 212-NE) Quadrangle.

Benbolt formation in Powell Station (T.V.A. 137-SE) Quadrangle, Tennes-
see: 1.6 miles northeast of Heiskell ; road corner $ mile southeast of Fleanor Mill.

Murfreesboro formation (top) in Tennessee: On the west fork of Stone River
at its junction with U. S. Highway 70S, 14 miles northwest of Murfreesboro,
Murfreesboro (15’) Quadrangle.

Discussion—Protozyga uniplicata may be recognized by its elongate form,
short beak, and prominent anterior folding. It differs from P. microscopica in
its narrower form and less convexity; from P. elongata it differs in its much
shorter beak. It is much less rotund and convex than P. rotunda.

PROTOZYGA sp. 1
Plate 142, J, figures 44-48

Shell of about usual size for the genus, longer than wide ; oval to subpentagonal
in outline ; posterolateral margins forming an angle of about 90°. Lateral margin
broadly rounded ; anterior margin narrowly rounded. Surface marked by short
costae at the margins, 3 or 4 on each side.

Pedicle valve moderately convex in lateral profile and with the maximum con-
vexity at the umbo or just anterior to it; anterior profile narrowly convex and
with steep sides; umbo and median region forming a subcarinate fold which ex-
tends to the anterior margin ; fold marked by a shallow sulcus beginning at about
the middle of the valve and extending to the anterior margin; sulcus in fold
marked by a single costa extending the length of the sulcus; flanks nearly flat
and very steep.

Brachial valve gently convex in lateral profile and with the maximum con-
vexity just anterior to the umbo; anterior profile broadly convex but marked by
a narrow and shallow depression at the middle; umbonal and median region nar-
rowly sulcate; sulcus widening abruptly at the middle and extending to the an-
terior margin where it occupies more than half the width; sulcus occupied by 2
strong costae separated by a narrow sulcus which corresponds to the median
costa of the opposite valve. Flanks moderately convex and with steep postero-
lateral slopes.

Measurements in mm.—111392<, length 4.0, brachial length 3.7, midwidth 3.2,
widest part 3.3, thickness 2.0.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 689

Figured specimen.—111392a.
Horizon and locality—Meadow marble in Tennessee: 2 miles southeast of
Kiser, Meadow (T.V.A. 139-NW) Quadrangle.

Genus HALLINA Winchell and Schuchert, 1892

Hallina WINCHELL and SCHUCHERT, Amer. Geol., vol. 9, p. 291, 18902.

HALLINA GLOBULARIS Cooper, new species
Plate 143, K, figures 48-52

Shell large for the genus, subcircular in outline; valves subequal in depth;
sides gently rounded; anterior margin broadly rounded; anterior commissure
faintly sulcate. Surface paucicostellate ; costae confined to the anterior half and
numbering about 20.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity just posterior to the middle; anterior profile strongly convex, somewhat
narrowed medially and with long, steep, flat, lateral slopes. Umbonal region nar-
rowly swollen; median region strongly swollen; anteromedian third or half flat-
tened where a broad fold is very indistinctly visible; flanks steep. Beak strongly
incurved. Beak ridge short and sharp.

Brachial valve strongly convex in lateral profile and with maximum depth at
about the middle; anterior profile not so strongly arched as that of the pedicle
valve but strongly convex nevertheless; median and umbonal regions inflated.
Anterior third at the middle slightly flattened and forming a barely perceptible
sulcus. Flanks swollen, steep sided.

Measurements in mm.—

Length Width Thickness
Lig TEEN gt “tahoe eae Si ra le I rag oh 4.3 4.0 2.8
Paraty piel BR eee cate ees eae cee aes tooth 4.1 3.9 3.0

Types.—Holotype: 117257a; unfigured paratype: 117257b.

Horizon and locality—Auburn chert in Missouri: 4 mile east of Auburn, Els-
berry (15’) Quadrangle.

Discussion—This species is the largest member of the genus known and is
characterized by its globular form, rounded outline, and strongly swollen valves.

HALLINA LIRATA Cooper, new species
Plate 143, C, figure 12

Shell small, elongate oval in outline; valves subequally convex; sides and an-
terior margins rounded; anterior commissure rectimarginate. Surface marked
by about 26 direct, rounded costellae.

Pedicle valve moderately convex in lateral profile and with the maximum con-
vexity at the middle; anterior somewhat flattened; anterior profile broadly and
moderately convex with long, moderately steep slopes. Umbonal region moder-
ately inflated ; median region strongly swollen, the swelling extending nearly to
the margins ; lateral slopes moderately steep. Interior with short dental plates.

690 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve moderately convex in lateral profile with the maximum con-
vexity at about the middle; anterior profile broadly convex, less convex than the
pedicle valve. Umbo narrowed slightly at the beak, otherwise broadly swollen;
median region and flanks swollen.

Measurements in mm.—

Length Width Thickness

EROLO EY PEs 5 Ries Reel shee Cha Dee eee Beee ake 4.5 3.8 ?
Paratype (CU, 26401,( 1056) 4) .+, 4 serine 21 2.8 By

Types.—Holotype: Columbia Univ. 26401(1056) ; unfigured paratype: Co-
lumbia Univ. 26401(1056)a; unfigured and unnumbered paratypes on slab with
holotype.

Horizon and locality—Benner-Stover formation in Pennsylvania: In a small
quarry west of the road 1 mile south of Jacksonville, Centre Hall (15’) Quad-
rangle.

Discussion.—This species is distinguished from H. saffordi and H. globularis
by its very fine costellae as compared to those of the other two.

HALLINA SAFFORDI Winchell and Schuchert

Plate 142, F, figures 26-28; plate 143, J, figure 47
Hallina saffordi WINCHELL and ScHucHERT, Amer. Geol., vol. 9, p. 292, 1892; Geol. Minne-
sota, vol. 3, p. 473, pl. 34, figs. 55-58, 1895.—H ALL and CriarkE, Pal. New York, vol. 8,

pt. 2, p. 151, figs. 139, 141, 1804.
Zygospira saffordi (Winchell and Schuchert) BEECHER and ScHUCHERT, Proc. Biol. Soc.
Washington, vol. 8, p. 71, pl. 10, fig. 22; pl. 11, figs. 13, 13a, 1803.

Types.—Hypotypes : 123356a ; 117258a.

Horizon and locality—About the middle of the Lebanon formation in Ten-
nessee: At Lebanon and on the west side of U. S. Highway 41, 9} miles south-
east of Murfreesboro, Rutherford County; Columbia, Maury County; and 24
miles east of Priest, Franklin (15’) Quadrangle.

Subfamily GiassimnaE Schuchert, 1929

Small, smooth brachiopods with spirals compressed and directed toward the
median part of the brachial valve and with the jugum continuous.

IDIOSPIRA Cooper, new genus

(Greek idio, own; spira, spire)

Shells generally small, approaching or slightly exceeding 15 mm. in length;
subcircular to subelliptical in outline; valves subequal in depth; anterior com-
missure uniplicate; surface smooth, except for obscure short marginal costae at
the anterior margins generally confined to the fold and sulcus.

Pedicle valve with small incurved beak, elongate, like that of Protozyga, open
foramen, and small teeth. Dental plates strongly developed. Brachial interior
with divided hinge plate; sockets deep and long; outer socket ridge well de-
veloped ; hinge plates small, triangular, concave. Median ridge indistinct. Spire

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 691

similar to that of Glassia but with cones directed medially and toward the brachial
valve.

Genotype-—Camerella panderi Billings, Canadian Nat. Geol., vol. 4, p. 302,
1859.

Discussion—This genus has a very obvious camerelloid exterior appearance
but it differs from the members of the subfamily in being much more rotund and
in not having an erect beak. IJdiospira differs from Glassia which it resembles
in the form of the spire, in exterior and interior details. [diospira has a strongly
uniplicate anterior commissure although the fold of the brachial valve is seldom
very prominent. The folding usually takes the form of an abrupt wave of the
commissure and the development of a fairly strong tongue on the pedicle valve.
Idiospira also has, in some species, more or less well developed costae along the
margins.

Internally Idiospira differs from Glassia in possessing strong dental plates, a
subdued median ridge, and a wide foramen. The spire is different in having the
loose coils of the cone directed obliquely inward and toward the brachial valve
rather than inward as illustrated for Glassia.

IDIOSPIRA ? INORNATA (Weller)

Camarella inornata WELLER, Geol. Surv. New Jersey, Rep. on Paleont., vol. 3, p. 157, pl. 10,
figs, 8-10, 1903.

Although the interior characters of this species were not determined by Weller
and the types have not been reexamined in this study, the description and figures
make it clear that this species is not a Camerella. The tendency toward emargina-
tion of the anterior margin, the wave of the anterior commissure toward the
brachial valve, the subequal depth of the valves, and the closely appressed beak
of the pedicle valve are suggestive of assignment to [diospira.

Horizon and locality —Jacksonburg formation in New Jersey: On the hill
just east of the station, near Hainesburg, Delaware Water Gap (15’) Quad-
rangle.

IDIOSPIRA PANDERI (Billings)
Plate 108, F, figures 26-32; plate 195, F, figures 33-37; plate 195, H, figures 42-46

Camerella panderi BiLtincs, Canadian Nat. Geol., vol. 4, p. 302, 1859.—LocAn, Geol. Canada,
p. 143, fig. 78, 1863—HALL and CrarkeE, Pal. New York, vol. 8, pt. 2, p. 220, pl. 62,
figs. 19-23, 1893.—? Raymonp, Ann. Carnegie Mus., vol. 7, p. 250, pl. 36, figs. 31, 32,
I911.—WILson, Geol. Surv. Canada, Bull. 8, p. 118, pl. 11, fig. 2, 1946.

Two specimens of this species in the National Collection were prepared to
show the spire. These revealed a fairly tightly coiled spire with the apices di-
rected medially and obliquely toward the brachial valve. The details of the cardi-
nalia furnished in the generic description were also taken from specimens of this
species. Idiospira panderi has been widely identified in Trenton rocks of this
country and Canada, but a revision of these is in order. The number of speci-
mens of this genus in the National Collection is small, but a number of new
species are here separated.

692 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Idiospira panderi Billings is a globular species generally slightly longer than
wide with a strongly uniplicate anterior commissure and a fairly well-marked
fold on the brachial valve. The pedicle tongue is usually marked by a costa, and
the fold has a short depression to accommodate it, thus giving the fold an anterior
bicostate form.

Types.—Syntypes: G.S.C. 1148,a,b; figured hypotypes: 85329a, 853302,
92374a,c, 117251a.

Horizon and locality—Rockland formation in Quebec: On Allumette Island ;
same formation in Ontario: At Paquette Rapids; Stewarts Quarry, 25 miles
south of Rockland.

Lower Trenton formation in New York: North of Amsterdam.

Tyrone formation in Kentucky: 2 miles south of High Bridge; Curdsville,
Mercer County.

Auburn chert in Missouri: 4 mile east of Auburn, Elsberry (15’) Quadrangle.

Decorah formation (Guttenburg member) in Iowa: On M.St.P. and P. RR.,
1 mile north of Eagle Point Bridge, Dubuque.

Hull formation in Ontario, Canada: At Kirkfield.

IDIOSPIRA ? WARTHINI Cooper, new species
Plate 140, K, figures 63-72; plate 195, G, figures 38-41

Shell large for the genus, length and width about equal in the adult; outline
oval ; apical angle about 100° ; sides rounded; greatest width located just anterior
to the middle. Anterior commissure moderately strongly uniplicate; surface
smooth except for I or 2 costae at the anterior margin.

Pedicle valve moderately convex in lateral profile and with the maximum con-
vexity slightly posterior to the middle; anterior profile stronger than the lateral
one and with short, moderately steep lateral slopes. Beak moderately long. Umbo
and postmedian region swollen; sulcus originating at about midvalve, wide and
shallow, forming a short, wide tongue. Tongue marked by 2 costae that extend
almost to the middle of the valve. Sulcus bounded by 2 short, narrow costae.
Flanks swollen and with steep sides.

Brachial valve moderately convex in lateral profile and with the maximum
depth at the middle; anterior profile broadly domed. Umbonal and median re-
gions swollen ; fold inconspicuous, broad and low, confined to the anterior third
to fifth ; fold marked by 3 narrowly rounded costae. Flanks swollen, slopes steep.

Measurements in mm.—

Brachial
Length length Width Thickness
Holotype’ (GU, 2508OD) 5 sa siis anne wk 10.9 0.7 9.2 6.9
Paratype (UI. 250LGa ) cies tenes cst AD 10.9 12.0 ape
COIST Me Payee aay eee erie orns 9.6 8.9 8.9 4.9

Types.—Holotype: Columbia Univ. 25919b; figured paratypes: Columbia
Univ. 259192; U.S.N.M. 1172522.
Horizon and locality —Wappinger formation in New York: In the railroad

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 693

cut at Pleasant Valley, 6 miles northeast of Poughkeepsie, Poughkeepsie (15’)
Quadrangle.

Discussion—This species is unlike any other described American form. It is
larger and less globular in form than J. panderi and has more costae in the fold
and sulcus. It is most like Camarella thomsoni (Davidson) from the Stinchar
formation at Craighead, Girvan, Scotland. It differs from the Scottish species
in its larger size, less convex brachial valve and less costate anterior margin.
The Scottish species has 4 costae on the fold and a costa on each flank.

Superfamily SprrIFERACEA Waagen, 1883
Family CYCLOSPIRIDAE Schuchert, 1913

Spiriferacea with the crura continuous with the bases of the close-set, nearly
parallel primary lamellae; spiralia slightly introverted and with few volutions.
No jugum.

Genus CYCLOSPIRA Halil and Clarke, 1893
Cyclospira Hatt and CiarKE, Pal. New York, vol. 8, pt. 2, p. 146, 1893.

CYCLOSPIRA BISULCATA (Emmons)
Plate 142, L, figures 54-59

Figures of this species, which is the type of the genus and a large form, are
introduced for comparison with species assigned to Cyclospira from the Appa-
lachian Valley and elsewhere.

Figured specimen.—88272a.

Horizon and locality—Coburg formation (upper), in New York: In the
quarry east of Black River below Copenhagen, Carthage (15’) Quadrangle.

CYCLOSPIRA ? LONGA Cooper, new species
Plate 142,I, figures 39-43

Shell small, pentagonal in outline, longer than wide with the greatest width
at about the middle. Beak acute; shell posterior to middle narrowing rapidly to
the beak ; sides somewhat narrowly rounded; anterior margin narrow and gently
rounded. Anterior part of anterolateral extremities marked by 2 costae; surface
without other ornament than the costae and folds.

Pedicle valve about twice as deep as the brachial valve, moderately convex and
with the greatest convexity slightly posterior to the middle. Beak moderately
incurved. Umbo narrowly swollen. Fold low, extending to a point slightly an-
terior to the middle where it passes into 2 narrowly rounded costae bounding a
narrow sulcus. Flanks gently concave and with steep slopes to the margins.

Brachial valve evenly and gently convex in lateral profile, with greatest con-
vexity at about the middle. Posterior half slightly swollen and marked by a
shallow and narrow depression that marks the position of the median septum.
Sulcus originating slightly anterior to the middle, widening rapidly to the margin
where it occupies about half the valve width. Sulcus for its entire length occu-

694 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

pied by a narrowly rounded fold bearing a slight median longitudinal groove.
Furrows defining median fold deep; folds bounding sulcus low but narrowly
rounded. Median septum extending to point of origin of median fold.
Measurements in mm.—Holotype, length 4.0, width 3.6, thickness 2.3.
Type—Holotype: 111390.
Horizon and locality—Rysedorf conglomerate, near Albany, N. Y.
Discussion.—This species is close in form and outline to C. sulcata, but unlike
that species it is costate on the flanks, a feature uncommon in later species of
Cyclospira as far as known. The Rysedorf species differs from the Tennessee
one in having an elongated and narrow beak and a strong, narrow median fold
in the sulcus of the brachial valve. This species is placed in Cyclospira because
of the long, prominent, and thick median septum. The exterior resemblance to
Protozyga is striking, but the median septum is stronger than usual in that genus.

CYCLOSPIRA PARVA Cooper, new species
Plate 142, K, figures 49-53

Shell small for the genus, subpentagonal in outline, with the greatest width lo-
cated at about the middle; lateral margins rounded; front margin narrowly
rounded ; surface smooth.

Pedicle valve with strongly incurved beak; umbo and beak in profile forming
an acute angle. Umbo swollen and somewhat carinated, extended forward to the
front margin as a narrowly rounded fold. Fold flattened in the anterior third;
flanks in anterior profile forming an angle of about 90°, flattened to slightly con-
cave and with steep slopes to the margins.

Brachial valve about a third as deep as the pedicle valve, gently convex in lat-
eral profile; umbonal region slightly inflated; sulcus originating just anterior to
the umbo and extending to the front margin, widening and deepening anteriorly.
Flanks bounding sulcus well rounded and with moderately steep lateral slopes.

Interior: Median septum extending about half the length of the valve; spire
extending well beyond the middle.

Measurements in mm.—Holotype, length 4.1, width 3.6, thickness 2.3.

Types.—Holotype: 111391a; unfigured paratypes: 111391b-d.

Horizon and locality—Bromide formation (Pooleville member—O-oplecia
gouldi zone) in Oklahoma: Rock Crossing of Hickory Creek, about center sec.
35, 1.5 9., R. 1 E., Criner Hills, Carter County.

Discussion.—This species is smaller than C. sulcata, which it resembles, and
has a shorter sulcus. C. sulcata gives a more square-shouldered appearance than
the Oklahoma species.

CYCLOSPIRA PRECIOSA Cooper, new species
Plate 141, E, figures 25-32

Shell moderately large for the genus, length and width of a large adult about
equal; pentagonal in outline; sides rounded and with the maximum width at or

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 695

near the middle; anterior narrowed and truncated; strongly sulcate; surface
smooth.

Pedicle valve strongly convex in lateral profile, with the maximum convexity
anterior to the umbo; anterior profile narrowly convex and with steep, flattened
lateral slopes. Beak narrow and strongly incurved; umbo narrowly rounded;
median region narrowly rounded ; anterior region with low, narrow fold, flattened
or depressed longitudinally by a more or less shallow depression extending from
the anterior margin to the middle. Flanks flat or gently concave and steep.

Brachial valve moderately convex in lateral profile, the posterior half fairly
strongly convex but the anterior half bent strongly toward the pedicle valve.
Anterior profile broadly sulcate. Umbonal region marked by a shallow, narrow
sulcus which widens rapidly and deepens anteriorly. Flanks swollen and nar-
rowly convex. Sulcus without inner fold except near anterior margin where it is
more or less distinct.

Measurements in mm.— Brachial
Length length Width Thickness
Ebolotype at bidet apr. ashi. sys 29)4-4 tastes 6.5 5:7 5.9 3.9
Barina (W725 37) ous tects seine 6.6 5.5 5.8 4.0
ot (CASES) sues Ait 6.9 6.1 6.5 4.2

Types.—Holotype: 117253b; figured paratypes: 117253a,c.

Horizon and locality—Edinburg formation (Lantz Mills facies) in Virginia:
go feet above the Dinorthis transversa zone and go feet below the Oligorhynchia
zone, 0.6 mile northwest of the junction of Virginia County Highways 616 and
621, Richpatch, Eagle Rock (15’) Quadrangle.

Discussion.—This species resembles C. bisulcata but does not attain the large
size of the later Trenton species. Cyclospira bisulcata is a much more robust
form and has a more prominent fold in the sulcus of the brachial valve.

CYCLOSPIRA QUADRATA Cooper, new species
Plate 141, A, figures 1-12; plate 143, B, figures 7-11

Shell small for the genus, length and width about equal ; pentagonal in outline ;
sides rounded ; greatest width at about the middle; shoulders prominent. Surface
smooth.

Pedicle valve fairly strongly convex in lateral profile; narrowly humped in
anterior profile. Beak long, incurved; umbo somewhat inflated; median region
narrowly convex; front with a poorly defined fold flattened on its surface. Flanks
flat but sloping steeply to the margins.

Brachial valve unevenly convex, the posterior half somewhat inflated but the
anterior half extending toward the pedicle valve; anterior profile broadly and
gently convex. Umbo and median region inflated; sulcus narrow and shallow at
the posterior but broad and fairly deep anteriorly. Flanks moderately inflated.

Measurements in mm.—
Length Width Thickness
EA GINIV DEEN. sit atebiee sc ssia 4 ele Slaves ne sie'e gr ecale 4.4 4.3 2.2
Paratype CLT725OD) eiciceiin's seis ace nuek ee ees 4.2 4.1 2.4

696 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 117256a; figured paratypes: 117254, 117255a, 117256b.

Horizon and locality—Edinburg formation (top of the Liberty Hall facies)
in Virginia: 4 mile south of Dunkard Church, 6.9 miles S. 80° W. of Natural
Bridge, Natural Bridge (15’) Quadrangle.

Edinburg formation (lower Nidulites zone) in Virginia: From a cut on U. S.
Highway 11, Hupp Hill, 1 mile north of Strasburg, Strasburg (15’) Quadrangle.

Martinsburg formation (=Salona) in Virginia: On Virginia Highway 617=
910, 0.15 mile north of Green Mount Church, Broadway (15’) Quadrangle.

Discussion.—This species is characterized by small size, and quadrate form.
It is suggestive of C. sulcata but is less elongate and has a shorter and wider
sulcus. The same features will distinguish it from C. parva.

CYCLOSPIRA SULCATA Cooper, new species
Plate 142, M, figures 60-69

Shell small, pentagonal in outline, inequivalved ; lateral margins gently rounded
but with distinct shoulders located slightly posterior to the middle ; greatest width
at or slightly anterior to the shoulders. Front margin truncated. Surface smooth.

Pedicle valve deep, evenly and moderately convex in lateral profile, strongly
convex in adult forms with the greatest convexity shifted to the umbonal region.
Median region strongly elevated and narrowly rounded to form a low fold; sides
gently concave and diverging steeply to the margins. Anterior slope steep.

Brachial valve shallow, moderately convex in lateral profile and with the maxi-
mum curvature located at the front of the adult where the valve is geniculated
to form a tongue which fits into the anterior folded part of the pedicle valve.
Umbonal region slightly swollen; sulcus originating somewhat less than a third
the length from the beak, broad, deepening anteriorly, and with rounded section.
Flanks gently convex, narrow.

Interior: Median septum of the brachial valve extending almost to the middle;
descending processes of spire reaching nearly to front margin.

Measurements in mm.—
Length Width Thickness
EPONA coy outed heard akan bin oerentia come eewa tae 4.8 4.3 27
PA GALVIN chia tacit teehte actais «tease keds cuae Rare eae 4.6 3.7 2.0

Types.—Holotype: 111395b; figured paratype: 111395a.

Horizon and locality—Sevier formation in Tennessee: 1 mile southeast of
Whitehorn, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Chatham Hill formation in Virginia: Grayson Farm, 4 miles southwest of
Bland, Bland County.

Discussion.—This species can be recognized by its broad and rounded sulcus
in the brachial valve and the typically shouldered appearance of the pedicle valve.
It is different from C. Jonga in lacking a strong fold in the sulcus and obscure
costae on the flanks. Its differences from C. quadrata and C. parva are stated
under the discussion of those species.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 697

Genus TRIPLECELLA Wilson, 1932
Triplecella Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 26, sec. 4, p. 399, 1932.

Examination of the type specimen of this genus indicates that it belongs to
Cyclospira and is not a new genus at all. The type specimen is a single valve
marked medially by a moderately wide sulcus. At about the middle of the valve
a fold appears in the sulcus and widens anteriorly to occupy nearly all of the
sulcus at the front margin. In anterior profile the flanks bounding the sulcus
are narrowly convex and elevated slightly above the fold in the sulcus. Although
the original description states that “only one valve is known which appears to be
the pedicle valve,” comparison with the brachial valve of Cyclospira indicates
that the sulcation and development of a fold within the sulcus so characteristic
of Triplecella is identical to the folding in the brachial valve of Cyclospira. Cyclo-
spira bisulcata occurs in the Coburg formation which is the horizon of Triple-
cella. It seems evident, therefore, from exterior details, that Triplecella duplicata
is actually a brachial valve of C. bisulcata.

Suborder STROPHOMENOIDEA Maillieux, 1932
Superfamily PLECTAMBONITACEA Cooper and Williams, 1952

Family TAFFIIDAE Ulrich and Cooper, 1936

Shallow concavo-convex Strophomenoidea having a pseudodeltidium and chili-
dium ; brachial valve with cardinalia like those of the Orthidae, with or without
a cardinal process.

Genus TAFFIA Ulrich, 1926

Tafa Ulrich in Butts, Alabama Geol. Surv. Special Rep. 14, p. 99, pl. 18, figs. 13-17
(no description), 1926.—ULricH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 180,
1938.

TAFFIA PLANOCONVEXA Butts
Plate 172, E, figures 21-29

Taffia planoconvexa Butts, UtricH and Cooper, Geol. Soc. Amer, Special Pap. 13, p. 181,
pl. 37C, figs. 12-18, 1938.

Figures of this genus are introduced for comparison with Aporthophyla,
Toquimia and members of the Plectambonitacea. Taffia is at present the earliest
known strophomenoid brachiopod and is the possible progenitor of some of the
higher stocks. Its affinities to members of the Orthidae are obvious when the
figures of Taffia are studied.

Types.—Lectotype: 71461b; figured paratype: 71461a; figured hypotypes:
91586, 91588a, 91590a,b.

Horizon and locality—Odenville formation in Alabama: In the vicinity of
Odenville, St. Clair County.

698 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genus APORTHOPHYLA Ulrich and Cooper, 1936
Plate 163, C, figures 21-24; plate 164, A, figures 1-3

Aporthophyla UtricH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 625, 1936; Geol. Soc.
Amer. Special Pap. 13, p. 182, 1938.

This is another genus having rafinesquinoid appearance but with orthoid car-
dinalia, strong dental plates, and orthoid muscle scar in the pedicle valve. Illus-
trations of two species are introduced for comparison with Toquimia, Palaeo-
strophomena, and other Plectambonitacea.

Genus TOQUIMIA Ulrich and Cooper, 1936
Plate 164, B, figures 4-14; plate 195, E, figure 32

Toquimia Utricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 626, 1936; Geol. Soc. Amer.
Special Pap. 13, pp. 183-184, 1938.

In the summer of 1946 Cooper visited the type locality of Toquimia kirki
Ulrich and Cooper in Ikes Canyon, Toquima Range, Nev., and collected speci-
mens which add information to our knowledge of the genus and which help to
correct previous errors.

The exterior of the shell is definitely rafinesquinoid, but the brachial valve be-
comes flat or gently convex in the anterior half. Inside the pedicle valve the
muscle field is large and has subflabellate diductor-adjustor impressions. An-
terior to the adductor scars and enclosed by the diductors is an oval pit. Anterior
to the diductors is a large callosity suggestive of the one seen in Titanambonites
or Sowerbyites. The visceral region is defined by an elevated ridge a few milli-
meters inside the anterior margin. Over this ridge and on the flat area anterior
to it are located the main distributaries of the pallial trunks.

An error mentioned in connection with the pedicle valve in the original de-
scription is the statement that a minute foramen is present. The new material
includes specimens showing the interareas and beaks to perfection (117567h),
but presence of a foramen was unconfirmed.

An excellent brachial interior was obtained by dissolving the shell from a piece
of sandy matrix. This specimen reveals a thin median septum rising to a low
crest just anterior to the middle. The cardinal process is short-shafted but with
a bulbous myophore which bears a strong median ridge and a weaker one on
each side. The brachial processes are short, flat blades. Like the pedicle valve,
the brachial valve has a thickened area about 5 mm. posterior to the anterior
margin. The thickening is strongest where the median septum terminates. The
pallial distributaries form channels in the thickening and extend across the low
marginal area to the anterior margin. The thickened area of the pedicle valve lies
somewhat anterior to that of the brachial valve and the two serve as a straining
device when the valves are in contact.

Toquimia is suggestive of Palaeostrophomena and is undoubtedly related to
that genus. Toguimia has, however, a different lateral profile, rafinesquinoid
ornamentation, lesser development of the median ridge, more flabellate muscle
scars, and greater development of subperipheral thickenings. The differences be-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 699

tween Toquimia and Aporthophyla have been stated by Ulrich and Cooper (1938,
p. 182).

Types—Lectotype : 91595a; paratypes: 91595b-f ; figured hypotypes: 117567a,
d,e,f,h,j ; unfigured hypotypes: 117567b,c,g,i.

PELONOMIA Cooper, new genus

(Greek pelos, mud; nomos, abode)

Shell small, subrectangular in outline with the hinge as wide or wider than
the midwidth ; planoconvex in profile ; pedicle valve with median fold and brachial
valve with median sulcus. Surface finely multicostellate. Shell substance coarsely
pseudopunctate.

Pedicle valve with short interarea and rudimentary pseudodeltidium. Muscle
area small, wider than long, bounded by short, thick dental plates and an anterior
rim.

Brachial valve with generalized interior consisting of a small, thickened but
simple cardinal process and rounded chilidium. Notothyrial cavity shallow,
bounded by short, delicate, primitive, rodlike brachiophores. Median ridge absent
but its place marked by two rows of strong but distant nodes. Rest of surface
coarsely but distantly granulose.

Genotype.—Orthis delicatula Billings, Geol. Surv. Canada, Paleozoic fossils,
vol. I, p. 217, 1865.

Discussion.—This little genus is particularly characterized by its planoconvex
form, coarse pseudopunctae, and the generalized character of the brachial in-
terior. It is unique among these early brachiopods in lacking a median ridge or
median septum. The exterior is plectambonitid, but the plectambonitid brachio-
pods are generally characterized by one or more septa. Pelonomia suggests
Eostrophomena Walcott in its shape and size, but that genus has a different cardi-
nal process and possesses a median ridge.

PELONOMIA DELICATULA (Billings)
Plate 223, E, figures 8-10
Orthis delicatula Brtu1ncs, Geol. Surv. Canada, Paleozoic fossils, vol. 1, p. 217, 1865.
Figured hypotypes.—117557, 117558.

Horizon and locality—Table Head series in Newfoundland: At Table Head;
4 miles northeast of Portland Creek; 1 mile west of Aguathuna, Port-au-Port.

Family PLECTAMBONITIDAE Kozlowski, 1929

Strophomenoidea with normal or reversed convexity, usually finely costellate.
Cardinal process simple. Brachial processes short and slender. Pseudodeltidium
and chilidium present.

Subfamily PLecTELLINAE Opik, 1930

Finely costellate, with simple orthoid cardinal process, imperforate pseudo-
deltidium.

700 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 127

Genus INGRIA 6pik, 1930
Plate 163, B, figures 7-20

Ingria Optx, Brachiopoda Protremata der estlandischen Ordovizischen Kukruse-Stufe, Acta
et Comment. Univ. Tartu, ser. A, vol. 17, No. 1, p. 57, 1930; idem, ser. A, vol. 23, No. 3,
PP. 13-17, 1932.—ULrRicH and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 185, 1938.
Palinorthis UtricH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 625, 1936.

In 1936 Ulrich and Cooper proposed the genus Palinorthis for an unusual
species from the Ordovician east of Frenchman Flat, Las Vegas (1°) Quad-
rangle, in southern Nevada, with genotype P. cloudi. This genus later proved
to be a synonym of Opik’s genus Ingria. In 1939 Bridge and Cooper collected
additional material of Ingria cloudi. After being etched from the limestone the
specimens constitute an excellent series. The species proves to be a variable
one, but the variations include even minor details shown by Opik’s specimens
from Rog6o Island.

As revealed by the Nevada examples /ngria possesses the peculiar double
tooth so prominent in Palaeostrophomena. It also has a few accessory denticles
on the hinge margin on each side of the tooth. Some specimens show an unusu-
ally large development of the adustor scars. Most of the specimens have the beak
filled with adventitious shell deposited under the pseudodeltidium and welding
that structure to the apex. Considerable variation occurs in the cardinal process ;
it varies from slender to moderately thick but retains its septumlike character in
all the specimens. In the pedicle valve the thickening anterior to the adductor
scars varies from a slender ridge to a wide triangular or somewhat rhomboidal
patch.

This genus so far has been found in the United States only at the Frenchman
Flat locality.

Types.—Figured hypotypes: 117559b-g,j; unfigured hypotypes: 117559a,h,ji.

Family LEPTESTIIDAE Opik, 1933

Plectambonitidae with shells of normal and reversed convexity, having a promi-
nent median ridge or septum. Cardinal process trilobed and chilidium narrowly
elevated.

Subfamily LeptestimnAE Opik, 1933

Leptestiidae with prominent median septum.

Genus PALAEOSTROPHOMENA Holtedahl, 1916 (emend. Spik, 1933)

Palaeostrophomena HortepAut, Vidensk. Skrift., I, Mat.-Nat. 1915, No. 12, p. 43, 1916;
emended, Opik, Acta et Comment. Univ. Tartu, ser. A, vol. 24, p. 24, 1033.

Holtedahl named Strophomena concava F. Schmidt as type of his new genus.
Later work by Opik, however, showed that the named type and the Norwegian
specimens figured by Holtedahl are not congeneric. Opik therefore proposed
the genus Jnversella for the S. concava of Holtedahl (not Schmidt) and emended
Palaesotrophomena on the basis of a study of Schmidt’s type specimens of
S. concava.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 7O1

Several species of Appalachian brachiopods appear to conform to the details
of the emended Palaeostrophomena as described and illustrated by Opik. The
Esthonian shells, however, differ from the American ones in size, thickness of
shell, and ornamentation. The Esthonian specimens are more wrinkled and are
larger than any of the American species. The interior details of the American
species conform to those of Palacostrophomena described and illustrated by Opik.
Details of the interior of the pedicle valve of the Esthonian form, however, are
not known, and this gap in knowledge leads to some doubt as to precise generic
assignment. In spite of this gap in our knowledge the American shells are as-
signed to the emended Palagostrophomena. The following remarks on generic
characters are based on the five known American species.

The lateral profile is resupinate, i.e., the young shell is generally concavo-
convex but in the adult the convexity is reversed. Thus the young stages of
Palaeostrophomena have normal convexity, but the anterior of the pedicle valve
is more or less deeply concave and that of the brachial valve is more or less
strongly convex. The ornamentation consists of costellae of unequal size, the
stronger ones separating groups of finer ones. Strong concentric wrinkles are
a common feature of the Esthonian shells, but in the American species these are
generally confined to the posterior margins. Both interareas are moderately long ;
the notothyrium and delthyrium are both narrow and are covered by strongly
elevated and narrowly convex chilidium and pseudodeltidium.

Inside the pedicle valve the teeth form one of the most prominent features be-
cause they are double, consisting of the tooth and an accessory dental process.
The tooth consists of a flat blade that grows obliquely forward from the apex.
Normally the inner edge of the tooth track forms the margin of the delthyrium,
but in Palaeostrophomena a deposit of shell substance is laid on the inner side
of the tooth to protrude at its anterior end. In articulation the tooth rests on the
outer or socket surface of the brachiophore and the accessory tooth rests on the
inner surface of the brachiophore. The narrow space between the tooth and the
accessory tooth receives the carinate edge of the brachiophore. The accessory
tooth seems to be formed of adventitious deposit.

Dental plates are lacking in the adult forms of the American shells and seem
also to be lacking from the specimens figured by Opik. False dental plates, how-
ever, composed of adventitious shell extend from the teeth for a short distance
on each side of the muscle field forming a fairly high ridge in some instances.

The muscle field of the pedicle valve of all the known species is large and oc-
cupies a generous portion of the interior. The field is generally pentagonal in
outline with the muscle scars converging to the apex and subparallel on the
sides. The anterior is deeply emarginate. Adjustor scars are visible at the base
of the accessory teeth or their extensions, the false dental plates. The diductor
scars are elongate, narrow, and usually extend to the valve middle or anterior
to it. In some specimens low callosities appear at the anterior ends of the diductor
scars. The adductor field forms a short, flattish, somewhat rectangular scar, often
with longitudinal striation at the apex. Its anterior end never reaches the anterior

702 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ends of the didictors. Actually the diductor scars are often separated by a cal-
losity or elevation at the anterior end of the adductor field.

The pallial marks of the pedicle valve are deeply impressed in all species of
the genus. A prominent trunk is given off at the anterior end of each of the
diductors, one branch of which turns toward the middle and then turns again
to extend to the front margin. Another branch extends almost directly toward
the front margin while the third branch turns posterolaterally. All these branches
send off numerous subsidiary channels. The pallial marks themselves consist of
narrow channels separated by low ridges so that each main pallial trunk in reality
consists of two narrow parallel channels.

The ovarian impressions are usually large and well developed.

The pseudodeltidium is a narrow arch with its side laid against the deposit
forming the accessory tooth. The plate is further cemented by adventitious shell
laid on the sides of the delthyrial cavity and the inner surface of the pseudo-
deltidium.

The brachial interior of American Palaeostrophomena is known well in three
species. These have deep sockets and flat-bladed, rather delicate brachiophores.
These are distinctly orthoid in structure. The notothyrial platform is moderately
thickened and is the seat of attachment of a prominent cardinal process. The
shaft of this structure is short and stout; the myophore is characterized by a
strong and elevated median ridge which stands between two lower ridges. The
three ridges are subparallel and separated by deep but narrow grooves. The
chilidium arches over the myophore and nearly covers it. The brachiophores and
cardinal process are completely independent. The median ridge is narrow and
strongly elevated, rising to a point anteriorly and sharply cut off at the front.
The adductor field is moderately wide at the posterior and tapers to a point an-
teriorly. The posterior scars are the larger, and both scars may be striated and
elevated on the margins.

Pallial marks are prominent in the brachial valve as well as in the pedicle valve.
As in the other valve the pallial trunks consist of parallel narrow grooves sep-
arated by low ridges. A major trunk extends anteriorly on each side of the
median ridge. Another trunk extends more or less obliquely from the point of
separation of the anterior and posterior adductor pairs. Ovarian impressions are
strongly developed as in the opposite valve.

PALAEOSTROPHOMENA ANGULATA Cooper, new species
Plate 168, B, figures 3-10; plate 194, C, figures 19-22

Shell small for the genus, wider than long with the width at the hinge varying
from about 14 to 2 times the length. Cardinal extremities acutely angular, auricu-
late to submucronate. Lateral margins sloping inward; anterior margin broadly
to narrowly rounded. Surface beautifully ornamented by costellae of different
sizes and fine concentric fila. Costellae of three sizes, the larger ones appearing
in three generations, a median costella stronger and wider than the rest usually
marks the center of the pedicle valve. Umbonal region usually marked by 3

PARTE CHAZYAN AND RELATED BRACHIOPODS—COOPER 703

primary costellae on each side of the median one. Costellae of intermediate size
intercalated in 2 generations as the shell grows so that an adult has about 8
of the primary and intermediate costellae in a space of 5 mm. at the front margin.
Spaces between larger costellae occupied by about 4 very fine costellae that are
cancellated by crowded concentric fila. Oblique wrinkles, often of considerable
length, mark the shell just anterior to the posterior margin.

Pedicle valve nearly flat in lateral profile ; very slightly convex in the posterior
half but flattened in the anterior portion. Umbo narrow, slightly swollen; beak
small and protruding slightly posterior to the posterior margin. Anterolateral
region flanking depressed anterior part thrown into a slight broad fold. Cardinal
extremities somewhat flattened. Interarea short and flat; apsacline to nearly
procline ; pseudodeltidium narrow and strongly convex.

Brachial valve only partially known from the exterior. Umbonal region con-
cave. In order to fit the interior of the pedicle valve the brachial valve must be
slightly convex in the anterior region.

Interior of pedicle valve with a moderately deep delthyrial cavity well filled
at the posterior by callus. Valve well thickened just inside the periphery, this
thickened portion of the interior giving the resupinate profile to the species.
Muscle field large, occupying most of the visceral region. Adjustors located at
the base of the dental plates as usual; diductor scars long and slender, generally
with a low ridge running the length of the middle of the scar. Adductor impres-
sions large. Pallial sinuses deeply impressed. Teeth double; dental plates stout,
giving off ridges that bound the exterior of the muscle field.

Brachial valve with cardinal process typical of the genus.

Measurements in mm.—

Hinge
Length Midwidth width Thickness
Holotype Hi PO, ROU 8.1 11.0 15.4 ?
Paratype. (111080b) fais. ; dese ceeites 8.5 12.8 15.8 ?
7 CRP HOROET «flier aiers, «esis 8.0 11.6 13.9 ?
; (Cac 2 a ree eee 7.9 10.8 12.1 ?

Types.—Holotype : 111080a ; figured paratypes: 111080b-f, 111084, 111085a,b;
unfigured paratype: 111080g.

Horizon and locality.—Botetourt formation in Virginia: 4 mile southwest of
Catawba at the junction of Virginia Highways 311 and 114, Salem (15’) Quad-
rangle.

Discussion —This species may be recognized by its great width, well-developed
cardinal angles, beautiful surface ornamentation, and short interarea on the
pedicle valve. The species can be distinguished from P. subtransversa which it
most nearly resembles by its smaller size, less numerous large costellae, and
nearly flat pedicle valve. The greater proportional length of P. superba will dis-
tinguish that species.

Palaeostrophomena angulata occurs in countless numbers at its type locality,
yet not a single good brachial valve was obtained. By far the majority of speci-
mens are isolated pedicle valves, but specimens with both valves in contact do

704 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

occur. Strangely, these specimens usually have the brachial valve crushed onto
the inside of the pedicle valve so that the posterior part of the two valves is frozen
together. The brachial valve must have been a more delicate shell than the
pedicle one.

PALAEOSTROPHOMENA RESUPINATA Cooper, new species
Plate 167, A, figures 1-28

Shell large, semielliptical in outline, wider than long with the hinge forming
the greatest width. Lateral margins gently convex; anterior margin fairly
strongly convex. Surface multicostellate, costellae of varying sizes, 11 of the
larger ones occupying a space of 5 mm. at the front margin.

Pedicle valve convex in the front half in lateral profile but concave in the an-
terior half. Beak broadly obtuse, scarcely protruding posterior to the posterior
margin. Umbonal and posteromedian region swollen. Valve geniculated gently
in the direction of the pedicle valve about 7 mm. anterior to the beak. Geniculated
half gently concave, the maximum concavity extending around the swollen por-
tion from the middle of the valve to the posterior margin. Cardinal extremities
flattened slightly, interarea long, strongly apsacline. Delthyrium covered by a
narrow, convex pseudodeltidium.

Brachial valve gently concave in the umbonal region and for a radius of about
6 to 7 mm. anterior to it. Anterior portion of the valve moderately convex ex-
cept in the posterolateral areas where it is slightly concave just anterior to the
cardinal extremities. The interarea short, flat, hypercline.

Interior of pedicle valve with most of interior occupied by a large and deeply
impressed muscle field. Adjustor scars long and slender; diductor impressions
reaching anterior to the middle; posterolateral margin of muscle field with more
or less well developed marginal ridge; vascula media located at anterior end of
diductor scars; secondary trunks deeply impressed ; adductor track elevated and
thickened.

Brachial interior with short brachiophores supported by a lateral thickening
of the notothyrial platform; median ridge narrow, moderately elevated and ex-
tending anterior to the middle; cardinal process with thick shaft ; myophore with
elevated median crest. Pallial and ovarian impressions strongly marked.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
FIOLOEY Pei ee css cee eee ee cies « 17.6 17.3 20.5 20.7 5.0
Paratype '(111069a) 0608 0. 16.7 16.1 20.7 23.4 3.6
§ (ai7e77d)% eter) he 11:2 10.5 14.3 15.8 2g
sf Bie 25 (02 14.7 13.7 18.2 ig he 28
é CE242400) 0c se yee Se 13.0 12.6 16.7 17.9 2.9

Types.—Holotype: 117377h; figured paratypes: 111069a, 111078c,d, 1173774,
c-g; unfigured paratypes: 111069b, 111078a,b,e, 117377b, 123249a-c.

Horizon and locality—Benbolt formation (lower) in Virginia: Just east of
meridian 1730”, east of Moccasin Creek, on north edge of Mendota (T.V.A.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 795

197-NE) Quadrangle; on the west slope of the hill 4 mile east of Cedar Point
School, Hilton (T.V.A. 197-NW) Quadrangle ; south side Mount Hagan School,
Hilton (T.V.A. 197-NW) Quadrangle; + mile east of Speers Ferry, Clinchport
(T.V.A. 188-NW) Quadrangle.

Same formation in Tennessee: On the north side of the road 1.1 miles north-
east of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle.

Discussion.—This species most closely resembles P. superba of the species de-
scribed in this monograph but differs in its larger size, thick valves, and more
rounded front margin. The anterior margin of P. superba is narrowly rounded
to subnasute with lateral margins sloping inward. P. superba is somewhat more
concave in the geniculated region than P. resupinata but is much less convex on
the brachial side.

PALAEOSTROPHOMENA ? RUGOSA Cooper, new species
Plate 176, B, figures 6-12

Shell large for the genus, wider than long, strongly resupinate; hinge form-
ing the greatest width and with acute cardinal extremities. Sides nearly straight
to oblique ; anterior margin strongly rounded. Surface costellate, costellae in two
sets, a larger group in a field of fine costellae; 6 or 7 of the larger costellae in
5 mm. at the front margin. Posterior margin marked by strong, oblique wrinkles ;
disk region of both valves marked by chevron-shaped wrinkles confined between
2 of the larger costellae.

Pedicle valve with posterior half convex in lateral profile but anterior half
strongly concave ; umbo and surrounding region moderately swollen ; most deeply
concave at about valve middle where shell geniculates in the direction of the
pedicle valve; sides and anterior half bent strongly in the direction of the pedicle
valve ; interarea moderately long, apsacline. Interior with long, slightly divergent
diductor scars.

Brachial valve fairly deeply concave in the umbonal and median regions to
about the middle of the valve where it is bent strongly toward the pedicle valve.
Angle of geniculation about 135°. Sides and anterior half gently convex in pro-
file and forming steep lateral and anterior slopes. Interior with bulbous cardinal
process, long and low median ridge most elevated at anterior end slightly anterior
to the valve middle ; brachiophores thin, small, orthoid. Myophore strongly tri-
lobed. Pallial impressions forming deep and narrow channels.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Bile 0S. EN SAR 13.8 13.6 16.9 18.6 sie
Baratype.. (127378a) vi oes ainwaye 14.7 ? 19.4 ? 22.3 o

Types.—Holotype: 117379c ; figured paratypes: 1173709a,e-g ; unfigured para-
types: 117378a-c, 117370b,d.

Horizon and locality—Botetourt formation in Virginia: On the south side of
U. S. Highway 60, about 1 mile northwest of Lexington, Lexington (15’)
Quadrangle.

706 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion—This species is characterized by its strongly resupinate profile
and the presence of Ptychoglyptus-like wrinkles in the visceral region. It is
thus unlike any other species of Palacostrophomena described herein. This
species may ultimately receive another generic designation, but it is not possible
from the material at hand. The brachial interior with its fairly strong median
ridge agrees with Palaeostrophomena although more material may prove this
species to be a resupinate form of Ptychoglyptus.

PALAEOSTROPHOMENA SUPERBA Cooper, new species
Plate 169, C, figures 13-29; plate 184, E, figures 13-18

Shell small for the genus, strophomenoid in habit, subtrapezoidal to subtri-
angular in outline. Cardinal extremities acutely angular to auriculate. Lateral
margins concave just anterior to the cardinal extremities, slightly rounded and
oblique to the anterolateral region; front margin narrowly rounded. Anterior
commissure broadly uniplicate. Surface marked by costellae of unequal size.
Young shells and the posterior part of older ones marked by a few primary cos-
tellae, 4 or 5 on each side of a prominent median costella. Between the primary
costellae 2 generations of intermediate size are intercalated, from 12 to 18 oc-
cupying a space of 5 mm. at the front margin. Space between intermediate and
primary costellae covered by fine radial costellae. Posterior margin marked by
oblique wrinkles.

Pedicle valve gently convex in the posterior region, becoming gradually con-
cave at about two-thirds the length where the valve is gently geniculated in the
direction of the pedicle valve. Umbonal region narrow and convex, extended
forward as a low fold to about the middle. Anterior third gently concave with
the concavity extending posterolaterally between the lateral margins and the
folded median part of the valve. Beak forming a blunt point, extending slightly
beyond the posterior margin. Interarea broad and flat, strongly apsacline. Del-
thyrium and pseudodeltidium narrow.

Brachial valve following the curvature of the pedicle with the posterior third
gently concave and the anterior two-thirds flat to gently convex. Umbo and
umbonal region moderately deeply concave and forming a sulcus corresponding
to the fold on the pedicle valve in the posterior third to half. Sulcus lost where
valve begins to flatten before geniculating. Region about cardinal extremities
moderately to steeply sloping toward the margins. Lateral and anterior slopes
moderately steep but the latter not as steep as the lateral slopes. Interarea shorter
than that of the pedicle valve, flat to slightly convex, hypercline. Chilidium short,
narrow, strongly arched.

Interior of pedicle valve with small teeth consisting of two articulating pro-
cesses: the tooth proper and a process on the inside of the tooth formed by an
extension of the sides of the deltidium. Delthyrial cavity moderately deep.
Dental plates, if present, obscured by callus deposit. Cardinal margin greatly ex-
tended in an anterior direction by deposition of callus under the palintrope and
flush with the cardinal edge. Low ridges surround posterior sides of the muscle

PART CHAZYAN AND RELATED BRACHIOPODS—COOPER 707

field. Adjustor scars long and slender, located on the outside margin of the
muscle field just inside the lateral ridge. Diductor impressions long and slender
extending for fully a third the length of the valve. Adductor impressions form-
ing an oval field with the pointed end extending into the callus filling the posterior
end of the delthyrial cavity. Pallial impressions deeply entrenched in the shell ;
the main vascula media extending from the anterior ends of the diductor scars
for a short distance and then branching. Vascula media separated by a low, wide
thickening of the shell. A second pallial trunk originates at about the anterior
end of the adjustor scar. Ovarian impressions small.

Brachial interior with a stout median ridge extending to about the middle of
the valve where its end is thickened and elevated. Brachial processes short and
stubby (?) ; notothyrial cavity filled by callus and notothyrial platform occupied
by a large cardinal process with bulbous shaft when viewed from the pedicle
valve side. In posterior view the process is a thin, elevated median ridge inti-
mately grown with the chilidium. Adductor impressions elongate, thickened at
the front edge of the anterior scar which lies inside the posterior smaller scar.
A pallial trunk extends anteriorly on each side of the median ridge.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PAOUILV BS | ois cies ec idesete oe vcore 10.5 9.0 11.6 13.6 1.5
Paratype CLUTOZOL) cas «sie oles wc 9.1 8.3 12.3 14.8 1.8
ee ( BEFO7O-1) 09...) 22 22. 12.3 ? 13.6 16.4 ?
, (7573812) sree .7 12.4 11.9 14.0 15.5 2.1

Types——Holotype: 111070m; figured paratypes: 111070f-i,p, 117380,
117381a-c; unfigured paratypes: 111070a-e,j,k,n,o, 117381d-n.

Horizon and locality—Arline formation on Concord (T.V.A. 138-SW) and
Louisville (T.V.A. 138-SE) Quadrangles in Tennessee: 4 mile southeast of
Friendsville ; 5 miles southeast of Knoxville; 100 yards southwest of the Negro
Cemetery, 4 mile northeast of Friendsville; 1 mile northeast of Friendsville.

Fetzer tongue in Tennessee: At the road bend 0.6 mile south-southeast of
Harrison-Chilhowie Academy, Walden Creek (T.V.A. 156-SW) Quadrangle ;
1.3 miles south of Sevierville, Pigeon Forge (T.V.A. 156-SE) Quadrangle.

Arline formation in Virginia: In the quarry at Marion, Marion (T.V.A.
218-SE) Quadrangle.

Discussion.—This species is characterized by moderate size, thin shells, fairly
strongly resupinate profile, and generally a somewhat narrowly rounded anterior
margin as well as a wide and often alate hinge and cardinal extremities. It differs
from P. subtransversa in its more elongate outline and from P. resupinata in its
thinner shell, generally smaller size, and more narrowly rounded anterior margin.

PALAEOSTROPHOMENA SUBTRANSVERSA Cooper, new species
Plate 168, C, figures 11-23

Shell wider than long, with the contour of Strophomena; cardinal extremities
acutely angular, auriculate; anterior margin broadly rounded; lateral margins

708 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

oblique ; posterior margin nearly straight. Shell multicostellate with about 11 of
the primary and intermediate costellae in 1 mm. at the front of a large adult. In
the younger stages the surface is marked by numerous primary and intermediate
costellae. Very fine costellae occupy the spaces between the larger costellae.
Obscure oblique wrinkles occur just anterior to the posterior margin.

Pedicle valve nearly flat in lateral profile, the posterior third to half very
slightly convex and the anterior portion very gently concave. About the pos-
terior half of the valve representing the shell up to the stage when it had reached
5 mm. in length is slightly swollen in the umbonal and median region. Anteriorly
and anterolaterally of this convex stage the valve is very gently concave. The
front portion is usually flattened, but the anterolateral portions are generally de-
flected slightly in the direction of the pedicle valve. Interarea nearly flat, strongly
apsacline. Deltidium long and narrow.

Brachial valve moderately to deeply concave in the median and umbonal por-
tions ; concavity extending to about or slightly anterior to the middle. Postero-
lateral areas just anterior to the posterior margin may be flattened or gently
concave. Lateral and anterolateral areas gently convex with gentle slopes to the
margins. Anterior slope gentle. Cardinal angles flattened to moderately convex
with moderate slopes to the margin. Interarea short, anacline; chilidium short,
strongly arched.

Interior of pedicle valve with stout double teeth, no dental plates, wide and
moderately long muscle field; diductor scars elongate and with thickened cal-
losity at their anterior ends; pallial marks strong.

Brachial valve having moderately elevated septum highest at its anterior end
and extending for about two-thirds the length. Brachiophores short and stout.
Cardinal process a simple ridge on a stout but not greatly elevated shaft. Second-
ary ridges from the chilidium are located on each side of the median cardinal
process. Pallial sinuses deeply impressed.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
1 a) 3 (017 Ce ER Cg eRe ee 11.9 TY 15.7 21.6 i
Paratype’ (1110051) SPs. 9.3 8.9 15.1 19.0+ 1.8

Types.—Holotype: 111065g; figured paratypes: 111065b,c,e,f,h-j; unfigured
paratypes: 111065a,d.

Horizon and locality—Arline formation in Virginia: At the entrance to
Porterfield Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW)
Quadrangle.

Discussion.—This species is characterized by its wide hinge and mucronate
cardinal extremities. In this respect it is most like P. angulata from which it
differs in its much greater size and different proportions. Inside the pedicle valve
the muscle scars of P. angulata are more clearly defined, the teeth are smaller,
and there is a lesser development of the pallial marks.

BART T CHAZYAN AND RELATED BRACHIOPODS—COOPER 709

APATOMORPHA Cooper, new genus
(Greek apate, deceit; morphe, shape)

Like Palaeostrophomena internally but having the normal curvature of Rafines-
quina, i.e., a flat or concave brachial valve. Shells small in the one known species ;
concavo- to plano-convex with a moderately long apsacline interarea on the pedi-
cle valve and a shorter hypercline interarea on the brachial valve. Surface multi-
costellate. Pseudodeltidium and chilidium long and narrowly arched.

Pedicle interior with small teeth consisting of an outer tooth and an inner ac-
cessory dental process produced on the inside of the delthyrial cavity. Delthyrial
cavity moderately deep; false dental plates extended anteriorly as a ridge on the
outside of the muscle field. Muscle field fairly large; adjustor scars small, lo-
cated at the inside base of the false dental plates. Diductor impressions elongate ;
adductor area small, situated on and beside a low ridge at the very posterior of
the delthyrial chamber. Area between diductors and in front of adductors, stri-
ated and roughened. Pallial sinuses strongly impressed ; vascula media wide and
short, consisting of two depressed channels separated by a low ridge; vascula
media bifurcating and sending one branch posterolaterally around the sub-
reniform ovarian impression. The other branch extends anteromedially.

Brachial interior with a low median ridge most elevated at its anterior end and
extending for more than half the length of the valve. Brachial processes short
and stout, orthoid ; cardinal process with thickened shaft cemented to notothyrial
platform. myophore surface with three ridges, the median ridge forming a high
thin septum ; the lateral ridges are lower and are given off from the ends of the
chilidium. Adductor field small, located posterior to the highest part of the
median ridge; anterior adductor impressions the larger and located inside the
posterior scars. Pallial trunks with two major branches originating at the inside
ends of the anterior adductors and running parallel to the median ridge to its
end where they bifurcate. A second branch originates at the place of division
between the posterior and anterior adductors and extends anterolaterally for
some distance then bifurcates sending one branch posteriorly and the other
anterolaterally.

Genotype.—Rafinesquina pulchella Raymond=Apatomorpha pulchella (Ray-
mond). (See below for reference.)

APATOMORPHA PULCHELLA (Raymond)
Plate 166, A, figures I-20
Rafinesquina pulchella RAyMonp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 206, pl. 3, fig. 10, 1928.

Shell rafinesquinoid in plan and profile ; moderately thick-shelled ; hinge form-
ing widest part ; cardinal extremities nearly rectangular to acute. Lateral margins
gently convex; anterior margin broadly to narrowly rounded. Anterior com-
missure rectimarginate. Surface multicostellate; costellae distant, narrowly
rounded and appearing in 4 generations. At the front margin of a specimen

710 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ro mm. long about 20 costellae occupy a space of 5 mm. Interspaces marked by
minute concentric fila.

Pedicle valve very slightly convex in lateral profile and forming a low arch
in anterior profile. Beak inconspicuous; umbo narrowly swollen and extending
anteriorly as a low fold to about the middle. Valve gently swollen in the median
portion, somewhat flattened at the anterior. Slopes to the lateral margins long
and gentle. Interarea fully twice the length of the interarea of the brachial valve.
Pseudodeltidium narrowly arched.

Brachial valve gently concave in the posterior half and the greatest concavity
is the narrow depression extending anteriorly from the umbo which corresponds
to the fold of the pedicle valve. Anterior half flattened or very slightly concave.
Anterolateral and lateral areas flattened to very slightly convex. Cardinal ex-
tremities deflected slightly toward the pedicle valve. Interarea short, strongly
hypercline.

Interior of pedicle valve with widely divergent diductor scars and deeply im-
pressed pallial trunks ; brachial valve with moderately elevated median ridge and
small adductor field. Cardinal process with bulbous surface facing pedicle valve.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Hypotype (110001!a).......... 12.0 10.5 13.9 14.4 1.5
Me (TVOOSIB) HO PAs 10.0 9.0 12.1 13.2 1.8
i (110896e)..3....... 8.1 7:3 9.3 10.0 1.5
f (GIT SO 52) ete canes 8.3 7.6 10.7 10.9 2
- (PEOSGED) obs cas sa 9.4 8.4 10.2 10.5 1.7

Types——Holotype: M.C.Z. 8624; paratype: M.C.Z. 8625 ; figured hypotypes:
T10895a,c, 1108g6a-d, 110g00a-f, 110901a,b; measured hypotypes: 1108q5b,
1108Q6e.

Horizon and locality.—Base of the Athens formation in Tennessee: At the L.
and N. railroad station in Athens, Athens (T.V.A. 125-NE) Quadrangle; above
the quarry, 600 feet S. 40° E. of the railroad crossing 1 mile northeast of the
courthouse in Athens, Athens (T.V.A. 125-NE) Quadrangle; Craighead Creek,
4 mile north of Christiansburg, Sweetwater (T.V.A. 131-SW) Quadrangle;
road along Meadow Fork just east of its junction with the valley road, 24 miles
northeast of Calhoun, Calhoun (T.V.A. 125-SW) Quadrangle; just southeast
of the intersection of the valley road and the road up Crouth Hollow, 24 miles
south-southeast of Riceville, Calhoun (T.V.A. 125-SW) Quadrangle.

Discussion.—This species was first described as a Rafinesquina, but the simple
cardinal process, the stout shell, and the form of the pedicle muscles are all un-
like that genus. Apatomorpha is closest to Palaeostrophomena and may be con-
sidered as having the same relationship to that genus as Strophomena has to
Rafinesquina. No other species of Apatomorpha is now known to which A. pul-
chella may be compared. None of the described brachiopods from Girvan, Scot-
land, appear to belong to Apatomorpha.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 7i\i

Genus GONIOTREMA Ulrich and Cooper, 1936
Plate 209, D, figures 14-22

Goniotrema ULricH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 626, 1936; Geol. Soc.
Amer. Special Pap. 13, p. 193, 1938.

During the present studies and collecting no more specimens of this interest-
ing brachiopod were found. Cooper visited Ikes Canyon in 1946 in the hope of
locating more of this species among other brachiopods but failed. A restudy of
the type specimen confirms the presence of the foramen which is much too regu-
lar to be a freak of silicification. The muscle scars are long, slender, and di-
vergent and reminiscent of Sowerbyites, as is the form and profile of the shell,
but the anterior callosities so characteristic of Sowerbyites are not present.

The brachial interior is somewhat reminiscent of Sowerbyites, but the septa are
much more subdued. Restudy of the cardinalia suggests that a mistake in inter-
pretation of the cardinal process was made owing to the silicification. It is prob-
able that the cardinal process is a single piece rather than a lobate form, and
the posterior part of it including the median ridge has been worn off. If this
interpretation be correct, the cardinal process becomes like that of Sowerbyites
and the genus should be classified with the Plectambonitacea.

Type.—Holotype : 92872.

Horizon and locality. —Upper Pogonip group in Nevada: In Ikes Canyon,
Toquima Range, Roberts Mountains (1°) Quadrangle.

PAUCICOSTELLA Cooper, new genus

(Latin pauculus, few; costa, rib)

Shells thin, generally wider than long, with the hinge forming the widest part ;
surface covered by two sets of costellae, a group of strong distant costellae in a
mat of fine costellae. Faint rugae may mark the posterior margin. Pseudo-
punctate.

Pedicle interior with short and rudimentary dental plates and large and wide
muscle field. Pseudodeltidium short. Brachial interior with delicate cardinalia ;
flat bladelike brachiophores ; small notothyrial platform; median ridge short and
thick, not connected conspicuously with notothyrial platform. Cardinal process
not seen, probably absent. Chilidium thin, strongly arched.

Genotype.—Paucicostella canadensis Cooper, new species.

Discussion.—This genus is based on a species whose details are difficult to as-
certain. The specimens occur as separated valves in a fairly soft granular lime-
stone. The shells are so thin that the usual method of burning the shell and then
developing the interior by use of needles failed to produce useful brachial in-
teriors, but the nature of the dental plates was determined. The interior features
of the brachial valve recorded above were obtained by etching the exterior of the
brachial valve with weak acid and interpreting the structures as seen in the wet
specimen.

The interior details are suggestive of those of Ptychoglyptus and Glyptam-
bonites, but the ornamentation sets Paucicostella off from both of those genera.

7i2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PAUCICOSTELLA CANADENSIS Cooper, new species
Plate 172, A, figures 1-6; plate 173, D, figure 24

Wider than long, cardinal extremities nearly a right angle or acute; sides
nearly straight or sloping toward the middle; anterior margin broadly rounded ;
surface costellate, large costellae numbering 8 or 10 on each side of the median
line and appearing in 2 generations; fine costellae covering entire surface, 6
or 7 in I mm. at the front margin.

Pedicle valve unevenly convex, with the convexity strongest at the umbo, the
median region somewhat flattened and the anterior part depressed toward the
brachial valve; anterior profile broadly and slightly convex. Umbo somewhat
narrowly swollen but not extended far forward. Median region flattened to con-
cave ; anterior quarter or third depressed to form a shallow, wide sulcus. Flanks
bounding sulcus flattened.

Brachial valve nearly flat in lateral profile ; same in anterior profile ; umbo con-
cave, the concavity short and shallow ; median region slightly inflated, the swell-
ing produced to the anterior margin to form a barely perceptible, broad fold;
flanks bounding fold flattened.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (pedicle valve) .......... 8.0 ? 11.9 11.7 ?
Paratype ( “ NE TzZO8E) ... 7.8 ? 13.4 13a ?
. Guia Me) LEPROSE) «ain OL ? 10.7 11.0 fe
. (brachial valve 1173905d).. ? 7.6 12.6 12.5 ?
oH (Guia oe TET QOSE iach 7.5 10.1 11.9 ?
iH Ts Hl LEA ZOSM ier. o.-18 8.1 II.0 11.9 ?
it Ci, uit ‘SnivTr7sorg) sug. 7.0 Tr3 ? I.I

Types.—Holotype: 117395b; figured paratypes: 117395a,c-f, 117394b; un-
figured paratypes: 117394a, 117395g-w.

Horizon and locality—Boulder in Mystic conglomerate in Quebec, Canada:
In Range 6, Lot 21, 2.6 miles north and 4 mile east of Mystic, Stanbridge Town-
ship; Range 6, Lot 20, same township.

Table Head series (upper) in Newfoundland: At Table Point Cove.

Discussion.—No other species of this genus is known to which this one can
be compared.

GLYPTAMBONITES Cooper, new genus
(Greek glyptos, engraved; ambon, umbo)

Suggesting Rafinesquina sensu stricto in outline and profiles. Pedicle valve
gently convex in lateral profile, brachial valve flat or very slightly concave. Shells
of large size. Surface marked by a few strong costellae in a field of very fine
costellae, strong oblique wrinkles marking the shell just below the posterior mar-
gin and on each side of the beak.

Pedicle valve with teeth small and simple, like those of the orthids; dental
plates short, produced forward as a low ridge on the outside of the muscle field,

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER Zig

which is small and elongate. Diductor-adjustor scars subequal, elongate, nar-
row, extended anterior to delthyrial cavity ; adductor field confined to delthyrial
cavity.

Cardinalia most suggestive of Sowerbyites with long, slender brachial proc-
esses supported in part by callus deposited under the cardinal process and their
inner surfaces. Cardinal process tripartite, with a median elevated ridge and two
lesser ridges on each side of it and separated by deep grooves. Face of cardinal
process toward the pedicle valve somewhat bulbous. Median septum thin, most
elevated at its anterior part, not reaching posteriorly to the cardinal process.
Adductor field small.

Genotype.—Glyptambonites musculosus Cooper, new species.

Discussion.—The shells of Glyptambonites are unusually beautiful with their
varied radial costellae and the oblique wrinkling of the hinge. The genus also
attains a large size for an early Paleozoic brachiopod. The interior details are
similar to those of Palaeostrophomena but the habit and profile are different from
those of that genus, which has a resupinate lateral profile.

Although the interior details are like those of Palaeostrophomena, some fea-
tures are differently developed than in that genus. The diductor scars are usually
much longer and more slender than in Palaeostrophomena. The adductor field
is enclosed deeply by the diductors, and the space between the diductors and
anterior to the adductor field is occupied by a longitudinally striated and granu-
lose area. The ovarian impressions are not as proportionately large as those of
Palaeostrophomena. Inside the brachial valve the brachiophores are more deli-
cate than those of Palaeostrophomena and the adductor field is smaller. The
pallial marks of both valves are similarly arranged to those of Palaeostrophomena.

GLYPTAMBONITES GLYPTUS Cooper, new species
Plate 168, A, figures 1, 2; plate 173, C, figures 13-23; plate 175, A, figures 1-8

Shell semielliptical in outline, wider than long, thin, concavo-convex. Lateral
margins slightly rounded; anterior margin broadly rounded. Cardinal extremi-
ties narrow acute to mucronate in the young but only slightly auriculate in the
adult and old shells. Surface ornamented by costellae of different sizes, from 5
to 7 of the stronger costellae mark the umbonal region and the young stages, but
in growth, costellae of intermediate size are intercalated between the primary
ones and the finest costellae, covering the whole surface. Total strong costellae
at the front margin about 20. Median costella usually the strongest of them all.
Very fine costellae from 5 to 7 in a millimeter occupy the spaces between the
stronger ones. Very fine concentric fila cancellate the fine costellae. Postero-
lateral region marked by strong oblique wrinkles and in the posterior quarter to
half of the valves transverse wrinkles may undulate the sectors of shell marked
out by the major costellae, these portions of the valve often suggesting the genus
Ptychoglyptus in ornamentation.

Pedicle valve very slightly convex in lateral and anterior profiles. Central and
posteromedian parts of the valve slightly swollen but the anterior, lateral, and

714 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

posterolateral regions flattened. Beak small and protruding slightly beyond the
posterior margin. Interarea flat, short, with narrowly rounded pseudodeltidium.

Brachial valve gently concave in lateral profile ; umbo concave, small ; posterior
part of valve nearly flat to very gently concave; median region slightly concave.
Lateral and posterolateral regions flattened. Interarea short, anacline to hyper-
cline. Chilidium moderately large.

Interior of pedicle valve with moderately deep delthyrial cavity; dental plates
mere remnants, divergent, with anterior ends thickened into false plates extend-
ing anteriorly around the outside margins of the muscle field. Teeth small, simple.
Muscle field small, narrow ; diductor impression elongate, narrow, extending far
anterior to the front of the delthyrial chamber. Adductor impressions confined
to delthyrial chamber and placed far back, separating the posterior ends of the
diductor impressions.

Brachial valve with cardinal process having a strong median carina and smaller
lateral accessory septa. Chilidium projecting over posterior half of cardinal
process; cardinal process protruding in the direction of the pedicle valve and
overhanging thickened area posterior to median septum. Brachial processes thin,
short, widely divergent. Median septum short, thin, elevated at its anterior end.
Adductor field subflabellate.

Measurements in mm.—
Hinge
width

Length Width Thickness
Eolotype'. IOP PROU IGA, BR 22.3 29.9 31.4 ?
Paratype: (12g250a) 263), oss. <4 1221? 15.8 ? 22.7 ?

Types.—Holotype: 117383a; figured paratypes: 117385b, 117386a-d,
117387a-g, 123248a,b, 123250b; unfigured paratypes: 117383b-l, 117384a-e,
117385a, 123250a,c-g.

Horizon and locality.—Effna formation in Virginia: At Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle; McNutt
Quarry, 12 miles southwest of Bland, Burkes Garden (15’) Quadrangle ; 2 miles
northwest of Brownsburg, Lexington (15’) Quadrangle.

Effna-Rich Valley formations in Virginia: At Porterfield Quarry, 5 miles
east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: 1.8 miles S. 4° W. of
Bethel Church, 5.9 miles east of Harrisonburg, Harrisonburg (15’) Quadrangle.

Pratt Ferry formation in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton
(15’) Quadrangle.

Botetourt formation in Virginia: At the junction of Virginia County High-
ways 731 and 724, 2 miles northwest of Brownsburg, Lexington (15’) Quad-
rangle.

Discussion —This species is based on few adult specimens. Most of the ma-
terial consists of young forms some of which have been dissolved out of lime-
stone and show the interiors to perfection. The adult is characterized by rather
distant strong costellae at the front margin and a modest wrinkling on the pos-
terior margin near the umbo. In G. musculosa the ornamentation has more

BART NE CHAZYAN AND RELATED BRACHIOPODS—COOPER 715

closely spaced strong costellae in the adult stages and the wrinkling on the pos-
terior margin is strong and extends along nearly the entire shell width.

GLYPTAMBONITES MUSCULOSUS Cooper, new species

Plate 171, B, figure 15; plate 175, B, figures 9, 10; plate 175, C, figures 11-13;
plate 176, A, figures 1-5

Shell large, plano- to concavo-convex, with the hinge forming the widest part;
sides gently rounded and sloping inward somewhat obliquely ; anterior margin
broadly rounded. Cardinal extremities acute to mucronate. Posterior margin
nearly straight. Surface finely costellate, costellae of two sizes and consisting of
large primary and secondary, tertiary and quaternary costellae in a mat of ex-
tremely fine costellae. Five or six of the larger costellae occupy a space of 5 mm.
at the front of a valve 19 mm. long. Fine costellae cancellated by moderately
strong concentric fila. Posterior margin and umbolateral slopes strongly wrinkled.

Pedicle valve evenly and faintly convex in anterior and lateral profiles; umbo
and median regions faintly swollen; area in front of cardinal extremities gently
concave. Interarea about twice as long as the brachial one; pseudodeltidium
narrowly swollen.

Interior with elongate diductor scars extending nearly to the middle of the
valve ; adductor impressions forming a small oval patch located in the apical angle
formed by the long diductors ; area immediately anterior to adductor scars and
between diductors strongly granulose; teeth moderately strong, double as in
Palaeostrophomena; false dental plates thick; ovarian impression a triangular
area of wavy lines and granules in the angle formed by the palintrope and the
false dental plates. Pallial marks prominent, the trunks narrow and numerous,
each trunk formed of two channels, thin and deep, separated by a low ridge.

Complete brachial exterior not yet known but a single impression of the
brachial interior indicates a nearly flat valve with hypercline interarea and nar-
rowly elevated chilidium. Interior with short and delicate brachiophores partially
buried in the tissue of the notothyrial platform ; cardinal process with short shaft,
bulbous at its posterior end and with triseptate myophore, the median ridge of
which is strongly elevated, adductor field forming an inverted pentagon bisected
by a moderately strong but low median ridge; anterior adductors smaller than
the posterior pair and forming the apex of the pentagon. Pallial marks promi-
nent, two trunks coming off the inside ends of the anterior adductors and ex-
tending anteriorly along each side of the median ridge; a second pair of trunks
originates at the line of junction of the adductor scars and extends anterolaterally.
Ovarian impressions moderately large.

Measurements in mm.—

Hinge
Length Midwidth width
Piolotyme wees. boy. eleteos ye Oath ho OY, SIR 25.4 33.2 37.0+
Patat wpe CLE 7 SOO). 6 ids sy sie os ajee vive ceecs on 18.7 26.0 35.0

4 CES PaBS Ee Se ce arte stew led on clareels 17.6 24.5 27.0+

716 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 117390c ; figured paratypes: 117388c,d, 117390a, 117391;
unfigured paratypes: 117388a,b, 117390b,d-n.

Horizon and locality—Oranda formation in Virginia: 0.6 mile northwest of
Linville Station, Broadway (15’) Quadrangle; on the Bowman Farm, 4 mile
east of U. S. Highway 11, about 1 mile southwest of Woodstock, Edinburg
(15’) Quadrangle ; just west of the junction of County Highways 617=910, and
777 about 4 mile north of Green Mount Church, Broadway (15') Quadrangle.
In Strasburg (15’) Quadrangle: on U. S. Highway 11, 4 mile south-southwest
of Tumbling Run, southwest of Strasburg; on Virginia Highway 55, 0.4 mile
west of U. S. Highway 11, north edge of Strasburg (type section of Oranda
formation) ; on U. S. Highway 11, 1 to 14 miles southwest of Strasburg; along
the railroad 4 mile west of Strasburg.

Discussion—Good specimens of this species are hard to obtain. The shell was
apparently a fragile one and was easily broken up. It is also an odd fact that the
brachial valve is exceptionally rare. A single specimen only was obtained. This
species is characterized by its large size and beautiful ornamentation. In com-
parison to G. glyptus it has more of the larger costae at the front margin than
does the Effna form.

GLYPTAMBONITES ? PLATYS (Butts)

Sowerbyella platys Butts, Virginia Geol. Surv. Bull. 52, p. 200, 1940; ibid., p. 100, pl. 95,
fig. 17, 1942.

This is a small specimen of poor preservation and uncertain generic characters.
It is a young specimen, besides, whose generic affinities cannot be established
from exterior examination. It might belong to Palaeostrophomena or possibly
Glyptambonites, in which it is here provisionally placed. The specimen is actu-
ally not adequate for a specific diagnosis. It has nothing to do with Sowerbyella
which has a strongly convex pedicle valve.

The specimen is 5.9 mm. long and 10.4 mm. wide at the hinge. The sides slope
obliquely toward the middle, and the front margin is broadly rounded. Cardinal
extremities acute. Pedicle interarea long, apsacline; interarea of the brachial
valve short and hypercline. Surface marked by three generations of strong cos-
tellae in a mat of fine costellae. Pseudodeltidium and chilidium narrowly rounded
and elongate as in Palaeostrophomena and Glyptambonites.

Horizon and locality The stratigraphic position of this specimen is not cer-
tainly known. A label in Butts’ handwriting states “Strasburg No. 7.” This
suggests that it is bed 7 of Ulrich’s section along the railroad tracks just east of
Strasburg Junction (or 3 mile west of Strasburg). If this is the correct interpre-
tation of the label, the specimen came from the Edinburg formation (Cyrtono-
tella zone). The matrix on the specimen is in accord with this designation. This
would be bed c of the geologic section in the vicinity of Strasburg. (Bassler,

1909, p. 56.)

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 717

TITANAMBONITES Cooper, new genus

(Greek titan, large; ambon, umbo)

Shells usually large, generally more than an inch wide; concavo-convex and
resembling Sowerbyites in exterior details: Costellae fine, distant, crossed by
prominent concentric fila. Shell substance pseudopunctate.

Pedicle interior with large, flat, oblique teeth having a deep crural fossette ;
dental plates absent ; muscle field large, resembling Sowerbyites with long diduc-
tor scars extending to the middle or beyond and lying at the base of large cal-
losities ; adjustor scars long and slender, located posterolaterally to the diductors ;
adductors constituting a small somewhat rectangular patch just anterior to the
posterior junction of the diductors; ovarian impressions small. Pallial impres-
sions prominent, vascula media extending anteromedially from anterior end of
diductor scar and occupying the callosity at the end of the diductor scar; minor
distributaries occupying the inside of the trail. Pseudodeltidium a long, narrow
arch.

Brachial valve with low median septum not prominent anterior to the cardi-
nalia but rising to a crest anteriorly and partitioning the shell cavity where the
trail is geniculated from the body. Brachiophores small, short, divergent; car-
dinal process a boss excavated on the side facing the anterior but with a trisep-
tate myophore, the median ridge being the highest; chilidium narrowly convex,
arched over proximal end of cardinal process; cardinal process supported by
shell substance deposited between the brachial process and the side of the cardi-
nal process. Adductor field small, the posterior adductors the larger; pallial
trunks strongly impressed, a large trunk extending anteriorly on each side of
the median ridge and another major trunk extending anterolaterally from place
of junction of anterior and posterior adductor pairs. Ovarian impressions mod-
erately well developed.

Genotype.—Titanambonites medius Cooper, new species.

Discussion—The members of this genus are fairly easy to recognize because
of their general resemblance to Sowerbyites. They are, however, usually much
larger than any known members of that genus and the brachial valves are very
different. Titanambonites has an interesting ornamentation which is unlike the
usual plectambonitids in not having the fine matrix of extremely small costellae.
In the genus under consideration the costellae are moderately distant and appear
in several generations. They are crossed by fine but prominent concentric fila
which cover the whole shell. In this respect Titanambonites resembles the
Esthonian genera Leptestia and Ingria. In this respect, too, it is unlike Sower-
byites.

The pedicle interior contains a number of interesting anatomical features. Den-
tal plates are absent, but the spaces between the palintrope and the inner shell
surface are the sites of thick shell deposit, so thick in some specimens that the
shell material protrudes anterior to the margin of the palintrope to form a slightly
oblique ridge. The muscle field with its prominent callosities anterior to the di-
ductor scars is very suggestive of Sowerbyites. The callosities are usually very

718 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

strong, and the vascula media take their origin at the anterior end of the diductor
muscle on the callosity. Another pallial trunk of importance originates at the
anteromedian edge of the ovarian impression. The latter are small and seem to
be better developed in the pedicle than the brachial valve.

The cardinal process is of interest because it seems to have no shaft or at least
a minimum development of that structure. The process arises abruptly from the
notothyrial platform and extends toward the pedicle valve. Its anterior face is
somewhat excavated but the myophore bears 3 prominent septa. The cardinal
process is reinforced by shell material deposited on the inside of the brachio-
phores, giving the appearance of the latter structures being welded to the cardi-
nal process. It does not, however, present the tentlike, deeply excavated plate
of Sowerbyella. The brachiophores are short and inconspicuous rods. The
median ridge is low in the adductor field but is elevated at its anterior end and
must have partitioned the anterior of the shell cavity into two chambers. As in
the pedicle valve the brachial valve has a thickening of shell material laid more
or less parallel to the posterior margin and just anterior to it. This taken in
conjunction with the ridge of the pedicle valve may have helped in shell
articulation.

Titanambonites is most like Sowerbyites of American genera. The pedicle
valves of the two genera are very close, but the brachial valves are quite different.
In Titanambonites no lateral septa have yet been observed, and the form of the
median ridge is different. Of European genera Leptestia is most like Titanambo-
nites. In the case of Leptestia differences occur inside both valves. Leptestia
has a small delthyrial cavity to which the muscle scars are confined. This cavity
is bounded by ridges suggestive of dental plates but possibly of different origin.
Anterior to the muscle field is a low median ridge which separates two excep-
tionally large subreniform ovarian impressions. The brachial valve of Leptestia,
too, is characterized by an exceptionally large subreniform ovarian impression
occupying most of the shell surface. The median septum of Leptestia is more
elevated than that of Titanambonites, and the cardinal process has a pronounced
shaft. The myophore, chilidium, and adductor field are like those of the American
genus.

TITANAMBONITES AMPLUS (Raymond)
Plate 177, A, figures 1-10; plate 179, A, figures 1-6; plate 180, B, figures 14-16;
plate 194, B, figures 11-18; plate 206, C, figure 13
Plectambonites amplus RAyMonp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 207, pl. 2, fig. 9; pl. 3, fig. 12, 1928.

Large for the genus, wider than long and with the hinge forming the widest
part ; sides sloping slightly obliquely toward the middle; anterior margin broadly
rounded. Costellae low, thin, rounded, and distant, about 2 or 3 to the millimeter ;
concentric fila strong.

Pedicle valve strongly convex in lateral profile, fairly strongly domed in an-
terior profile; beak scarcely protruding posterior to the posterior margin; umbo
moderately swollen, marked by a narrow, short fold at the beak; median region

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 719

strongly swollen, with steep slopes in all directions; anterior slope the steepest.
Pseudodeltidium narrow; interarea long, orthocline. Interior with short, flat
teeth; callosities appearing on each side of teeth and extending parallel to hinge ;
diductor scars long, extending to the middle and ending on high callosities ; pallial
marks strongly developed.

Brachial valve closely following the curvature of the pedicle valve, most con-
cave in the median region; umbo concave, the concavity continued anteriorly as
a shallow sulcus to a point anterior to the middle; interarea moderately long,
hypercline. Interior with well-marked but low median septum in the young ; old
adults with septum obscured by adventitious shell; adductor impressions small ;
pallial trunks well developed ; ovarian impressions moderately large, marked by
fine, wavy lines ; brachiophores small ; callosity parallel to edge of palintrope sepa-
rated from hinge margin by groove.

Measurements in mm.—

Brachial Surface Hinge
Length length length Midwidth width Thickness
Hypotype (117421)..... 23.6 20.1 30.5 29.1 ? $3.0 7 4.6
5 CIT7AZ2 ie .8 25.1 ? 35.0 37.6 ? ?
ss (177418) 00.5 i 23.9 ? 37.9 ? ?

Types.—Figured hypotypes: 117416, 117417, 117418, 117420a, 117421,
117422, 117423b.

Horizon and locality—Arline formation in Tennessee: 6 miles southeast of
Knoxville; north side of old wagon road in glade, } mile southeast of Friends-
ville, Concord (T.V.A. 138-SW) Quadrangle; McMullens, Meadow (T.V.A.
139-NW) Quadrangle; at the Gulley Cemetery, 0.4 mile northeast of St. Clair,
Bulls Gap (T.V.A. 171-SE). Quadrangle.

Fetzer tongue in Tennessee: At the bend of the road 0.6 mile south-southeast
of Harrison-Chilhowie Academy, Walden Creek (T.V.A. 156-SW) Quadrangle.

Little Oak formation in Alabama: On the point of the ridge, 1 mile south-
west of Newhope Church, Vandiver (15’) Quadrangle; 2 miles north of Pelham,
Bessemer Iron District (15’) Quadrangle; cut on the L. and N. RR., ¢ mile
northwest of Mosteller, Columbiana (15’) Quadrangle.

“Lenoir” formation=Little Oak in Alabama: East of Leeds, Leeds (15’)
Quadrangle.

Pratt Ferry formation: 0.2 mile southeast of Pratt Ferry, Blocton (15’)
Quadrangle.

Discussion—This is the largest and most robust of the species of this genus.
A few specimens only are known, but these show the species to be somewhat
variable in its convexity. Beside its great size this species differs from the
others described in the evenness of its lateral profile.

TITANAMBONITES CONVEXUS Cooper, new species
Plate 178, A, figures 1-8

Shell of about medium size for the genus, wider than long, with the hinge
equal to or wider than the width at the middle; sides sloping by a gentle curve

720 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

toward the middle; anterior margin broadly rounded ; surface distantly costellate
and with fine concentric fila.

Pedicle valve strongly convex in the median and anterior regions when viewed
in lateral profile ; anterior profile strongly domed; beak small; fold low and in-
conspicuous, extending from the beak to the middle; posterior third gently con-
vex ; median third strongly swollen and anterior third moderately convex; an-
terior slope steep, much steeper than the longer posterior slope. Interior as usual
for the genus.

Brachial valve gently concave in the posterior half, strongly concave in the
anterior half. Umbo concave; sulcus narrow and shallow, disappearing at or near
the middle; interarea long, hypercline.

Measurements in mm.—

Brachial Surface Mid- Hinge Thick-
Length length length width width ness Height
ER OlOty pes ue, ttoen Serer 0723 14.2 ? 24.4 25.3 5.0 7.3

Paratype (117424a).. 17.8 13.7 24.0? © 23.5 25.4 5-5 7.9
of (117424d).. 16.7 14.2 22.5 21.0 22.0 4.6 6.8

Types.—Holotype: 117424e; figured paratypes: 117424b,d; unfigured para-
types: 117424a,c.

Horizon and locality—Little Oak formation in Alabama: At the junction of
the Bailey Gap and Cahaba Valley roads, SWiSW43 sec. 13, T. 19 S., R. 2 W.,
1# miles northeast of Newhope Church, Vandiver (15’) Quadrangle; quarry
north of Pelham, Bessemer Iron District (15’) Quadrangle.

Discussion.—This species has about the same size and proportions as T. crassus
(Willard) but differs in having a more convex posterior half, a more rounded
geniculated part with a higher but less steep anterior slope. The brachial valve
of T. convexus is somewhat deeper than that of the Effna species.

TITANAMBONITES CRASSUS (Willard)
Plate 181, A, figures 1-9
Plectambonites crassus WiLLarD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 278, pl. 3, fig. 10, 1928.

Outline subrectangular, wider than long, hinge forming widest part. Lateral
margins sloping gently inward, nearly straight. Anterior margin gently and
broadly rounded. Surface costellate; distantly spaced larger costellae separated
by numerous finer ones. The larger costellae in the exfoliated condition have
the appearance of being double.

Pedicle valve gently convex in posterior three-quarters but strongly genicu-
lated in the anterior quarter. Point of geniculation about 16 mm. anterior to
beak ; angle of geniculation about 110°. Beak short, barely protruding posterior
to the posterior margin. Umbo slightly swollen and melting into the low con-
vexity of the median area; lateral areas flattened to slightly concave. Anterior
slope steep, the steepness decreasing posterolaterally as the length of slope de-
clines. Geniculated slope flat in profile. Interarea long, apsacline.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 721

Brachial valve with umbo a fairly deep pit and with interarea overhanging
the exterior slightly. Umbonal pit continued anteriorly for a quarter the length
of the valve as a shallow depression. Areas flanking this depression slightly
concave; posterolateral extremities flattened. Geniculated area nonexistent at
the cardinal extremities but rising medially to form a prominent anterior boundary
to the concave valve. Interarea fairly long, hypercline.

Interior of pedicle valve with elongate diductor impressions and strong termi-
nal callosities. Interior of brachial valve with strong median ridge extending
anteriorly to the place of geniculation. Adductor field small. Inner marginal
ridges strong.

Measurements in mm.—Hypotype (117425a), length 20.3, width 16.7, hinge
width 21.4+, thickness 5.0.

Types.—Figured hypotypes: 117425a-c,e.

Horizon and locality—Effna formation in Virginia: At McNutt Quarry, 12
miles southwest of Bland, Burkes Garden (15’) Quadrangle; Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—In size and general appearance this species suggest T. medius
Cooper, but sufficient differences in ornamentation and exterior shape can be seen
to establish their identity. The angle of geniculation of this species is smaller
than that of T. medius, and the geniculated portion is less convex and the angu-
larity more distinct. Although the details of the ornamentation of T. medius
cannot be determined accurately with the material at hand, the species does not
seem to have the strong concentric elements that are so conspicuous in T. medius.
Furthermore, the double character of the larger costellae was not detected in the
other species.

TITANAMBONITES MEDIUS Cooper, new species
Plate 178, B, figures 9-21; plate 185, B, figures 11-13

Shell large for the genus, semielliptical in outline, wider than long. Cardinal
extremities acute. Shell widest at or just anterior to the hinge. Lateral margins
nearly straight, sloping medially ; anterior margin broadly rounded. Surface mul-
ticostellate. Costellae distant, about 13 in the space of 5 mm. at the front margin.
Costellae and interspaces covered by fine, elevated, concentric fila, about Io in
the space of I mm., a strong median costella marking both valves.

Pedicle valve unevenly convex in lateral profile, the umbonal region moder-
ately convex, the body of the shell gently convex and the geniculated portion
fairly convex. Angle of geniculation 115° to 120° and geniculation taking place
about 17 mm. anterior to the beak. Anterior profile broadly convex. Umbonal
region narrow at the beak, widening anteriorly at median swollen area. Median
region somewhat swollen. Posterolateral slopes gently concave to the cardinal
extremities. Anterolateral and anterior slopes steep. A slight fold may be de-
veloped on the geniculated third. Interarea orthocline to apsacline, fairly long
and only slightly curved. Pseudodeltidium narrowly elevated.

Brachial valve concave and fitting closely into opposite valve. Umbonal re-
gion a moderately deep pit widening anteriorly into a median area that is some-

722 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

what more depressed than the surrounding valve. Anterior median third slightly
sulcate. Areas flanking median depression more gently concave. Interarea hyper-
cline, plane.

Interior of pedicle valve with strong, flat teeth supported by callus and set
somewhat obliquely to the delthyrial edge. Muscle area large with elongate,
divergent diductor scars terminating in prominent anterior callosities. Adductor
scars show as small pits located at the angle of divergence of the diductors.
Adjustors shorter than the diductors, long and narrow and located along the
inner margins of the delthyrial cavity. Pallial impressions strong, the major
trunks bifurcating at the anterior ends of the diductors and splitting into many
small channels anteriorly.

Interior of brachial valve with short brachiophores ; cardinal process a simple
boss welded with the chilidial plates to form a single piece overhanging a pit at
the posterior end of the median septum. Median septum extending slightly an-
terior to the middle, elevated in front and flanked by shorter septa on each side.

Measurements in mm.—

Brachial Mid- Hinge Surface Thick-
Length length width width length ness Height

FUGOEVTE? s sc0's oie sa 18.6 16.1 24.4 57 Ne ie mane?) a 6.6
Paratype (1174209a).. 20.1 ? 27.5 30.0 25.0 r ?
4 (1174201) .. 18.9 15.5 24.3 25.2 22.5 4.1 6.4
x (117428)... 18.8 15.0 22% 22.8 22.5 4.3 ?

Types.—Holotype: 117426b; figured paratypes: 117426a, 117429a-g; un-
figured paratypes: 117428, 117429h,i.

Horizon and locality.—At the base of the Athens formation (with Christiania)
in Tennessee: 1.9 and 2.5 miles northeast of Christiansburg, Sweetwater (T.V.A.
13I-SW) Quadrangle; Craighead Creek, 1 mile north-northwest of Christians-
burg, Sweetwater (T.V.A. 131-SW) Quadrangle; Fetzer tongue, south side of
the road 200 yards southwest of Blockhouse, Blockhouse (T.V.A. 148-NW)
Quadrangle.

Discussion—This species is characterized by its size intermediate between
T. amplus and the smaller species. It is very close to T. praecursor of the Lenoir
formation but differs in the shape and convexity of the valves. Titanambonites
medius is usually moderately acuminate at the cardinal extremities whereas
T. praecursor has rounded rather than oblique sides and the cardinal extremi-
ties are a right angle or slightly obtuse. The lateral profile of T. praecursor is
less full than that of T. medius.

TITANAMBONITES PRAECURSOR Cooper, new species
Plate 184, D, figures 6-12

Large for the genus, subrectangular in outline with the width greater than the
length ; cardinal extremities nearly a right angle; sides gently rounded ; anterior
margin strongly rounded ; ornamentation consisting of narrow, distant threadlike
costellae, covered by strong concentric fila.

Pedicle valve moderately convex in lateral profile, moderately domed in an-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 723

terior profile; umbo moderately swollen and somewhat narrowed at the beak;
median region moderately swollen and with steep anterior and posterior slopes
of about equal proportions ; lateral slopes moderately long and moderately steep ;
interarea long and orthocline. Interior with narrow diductor scars and moder-
ately large callosities at, or slightly anterior to, the middle.

Brachial valve moderately concave, maximum concavity anterior to the middle ;
mumbo concave, the concavity produced anteriorly nearly to front margin as a
shallow, poorly defined sulcus. Flanks bounding sulcus in posterior somewhat
flattened. Anterior third fairly strongly geniculated. Interior with short blade-
like brachiophores and thick cardinal process; median ridge low, elevated an-
teriorly ; adductor field small. Pallial trunks moderately impressed.

Measurements in mm.—

Brachial Mid- Hinge Surface Thick-
Length length width width length ness Height
FIGIGHY PE” 62. Peladis wos 20.9 17.3 27.0 28.4 25.5 5.0 6.9

Paratype (117430)... 21.5 18.6 27.4 29.2 25.6 4.4 6.4

Types.—Holotype: 117431a; figured paratypes: 117431b,c; measured para-
type: 117430.

Horizon and locality—Lenoir formation (base of Billingsaria zone) in Ten-
nessee: On both sides of east-west road leading into marble quarry, 1 mile north-
east of Friendsville, Concord (T.V.A. 138-SE) and Louisville (T.V.A. 138-SE)
Quadrangles.

Discussion—For differences between this species and T. medius see discussion
under that species.

TITANAMBONITES sp. 1

Plate 177, B, figure 11

This is a large specimen coming from the massive limestone above the Mac-
lurites beds and below the Pratt Ferry formation, which approaches T. amplus
(Raymond) in size but is shorter, more rounded in lateral profile, and seems to
have a greater height than specimens from McMullens, Tenn.

Figured specimen.—117432.

Horizon and locality—“‘Lenoir” (part with Christiania= Little Oak) in Ala-
bama: 0.2 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Genus SOWERBYITES Teichert, 1937
Sowerbyites TEICHERT, Rep. 5th Thule Exped., 1921-24, vol. 1, No. 5, p. 66, 1937.

Externally like Sowerbyella forming a semicircle in outline, interareas well
developed on both valves; hinge wide; surface marked by costellae of two sizes.
Delthyrium partially closed by a rudimentary pseudodeltidium.

Pedicle interior with muscle field occupying most of the median portion of the
valve. Diductor impressions divergent, exceptionally long, extending anterior
to the middle. Adductor impressions small, located within the delthyrial cavity.
Adjustor impressions located outside the diductors, elongate, separated from
them by a more or less well developed ridge. Teeth moderately large, composed

724 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

of two parts: an outer tooth flush with the interarea and situated at the angle
between the delthyrial margin and the edge of the palintrope, and an inner tooth
lying under the outer tooth. At the anterior ends of the diductor-adjustor scars
is a thick callus deposit bearing the proximal ends of the pallial trunks. One main
trunk extends from the anterolateral edge of the diductor impressions and two
extend from the end of the probable adjustor impressions. Ovarian impressions
well developed, subtriangular in outline and located between the muscle field and
the cardinal angles.

Cardinalia small but strong; cardinal process a simple ridge highest in the
direction toward the pedicle valve and descending toward the brachial valve.
Chilidial plates thick but low. Brachial processes short, flat blades widely di-
vergent and supported by callus which welds the cardinal process and chilidial
plates together. Median callus deposit extending forward to the point of origin
of median septum which it partially surrounds. Median septum extending to
beyond the middle where the valve is geniculated, expanded at its distal ex-
tremity. A shorter septum occurs on each side of the median septum, which di-
vides one set of adductors (?) from the others. Muscle scars 6 in number, 2 oc-
cupying the areas anterior to each brachial process and outside the accessory
septa, I located between the accessory septa and the median septum. Ovarian im-
pressions, subreniform in outline, occupy the region between the muscle field and
cardinal angles. One main pallial trunk extends from the single muscle scar,
and a large divided trunk extends anteriorly from the outside scars.

Genotype.—Sowerbyites medioseptata Teichert, Rep. 5th Thule Exped., 1921-
1924, vol. 1, No. 5, p. 66, pl. 12, figs. 16, 17, 1937.

Discussion.—This genus was described by Teichert from the “Trenton” of
Melville Peninsula, Arctic Canada. Although Dr. Teichert described and figured
the brachial valve well, the interior of the pedicle valve was unknown. Excellent
specimens of this genus from the Lincolnshire formation of the Southern Appa-
lachians and the Bromide formation of Oklahoma here figured give much added
information. The median septum of the brachial valve is the most important
feature of the genus, but the callosities at the anterior ends of the muscle scars
of the pedicle valve are likewise very characteristic and aid in quick identifica-
tion of the genus.

Besides the median septum a number of other significant differences from
Sowerbyella may be pointed out. In the pedicle valve of Sowerbyella a short but
prominent median septum divides the posterior portion of the muscle area.
Furthermore, the muscle scars of this valve are seldom, if ever, as long as in
Sowerbyites and are generally much more divergent.

The cardinalia of Sowerbyella show important differences from those of Sower-
bytes. The brachial process of the latter is much shorter and stouter than that
of Sowerbyella. The cardinal process of Sowerbyella is generally smaller but is
joined to the brachial processes and chilidial plates in much the same man-
ner as in Sowerbyites. The major difference is in the incomplete deposition of
callus over the cardinal structures. In Sowerbyella a deep cavity exists under

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 725

the cardinal process. The median septa extend nearly but not quite into the
cavity.
SOWERBYITES DELICATUS Cooper, new species
Plate 179, B, figures 7-20

Shell of about medium size for the genus, wider than long, length about two-
thirds the width; cardinal extremities approximately a right angle and slightly
auriculate; sides gently convex; anterior margin broadly rounded; ornamenta-
tion as in other species but very fine; about 10 of the larger costellae occupy
5 mm. at the front margin. Lamellae poorly preserved, observed mostly near the
front margin.

Pedicle valve moderately convex in lateral profile and with the maximum con-
vexity slightly anterior to the middle ; anterior profile broadly convex and slightly
humped in the median region; umbo narrowly swollen to form a low fold that
extends more or less distinctly to the middle or slightly beyond; median region
swollen ; flanks gently convex and with long, gentle slopes to the margins; an-
terior slope moderately long and moderately steep. Interarea long, apsacline.

Brachial valve concave, with the maximum concavity just anterior to the cen-
ter; umbo concave, the concavity extending nearly to the middle as a shallow
and narrow sulcus; flanks gently concave; interarea short, hypercline.

Interior of pedicle valve with moderately strong callosities at the anterior ends
of the diductor scars; pallial marks not pronounced. Interior of brachial valve
with small and short brachial processes; median septum strongly elevated and
thickened at the front; outside pair of lateral septa poorly developed.

Measurements in mm.— Brachial Hinge
Length length Midwidth width Thickness
EVOLObY PEM arsitrere blelovsiel sieie «esdiete ole 10.9 9.8 14.2 14.2 1.9
Paratype, (117300d.). a. aes 5.01 9.9 88 14.7 16.2 E7

Types.—Holotype: 117399e; figured paratypes: 117399a-d,f-h.

Horizon and locality.—Low in the Sevier shale in Tennessee: 1.8 miles S. 18°
E. of Athens, Athens (T.V.A. 125-NE) Quadrangle.

Discussion.—This species has been found only at a single locality where it oc-
curs in countless numbers in a calcareous sandstone that forms a reeflike mass.

Sowerbyites delicatus is characterized by its small size, moderately auriculate
cardinal extremities, gentle convexity of the pedicle valve, and gentle concavity
in the brachial valve. The species in unlike S. triseptatus in its small size and
relatively elongate form, and its cardinal extremities are not so strongly alate. It
is smaller than all the other described species except S. hami. It is larger than
the latter form but is not so convex in the pedicle valve nor so concave in the
brachial valve.

SOWERBYITES GILDERSLEEVEI Cooper, new species
Plate 183, A, figures 1-16

Shell large, semicircular in outline with slightly obtuse to acutely angular car-
dinal extremities. Anterior margin very broadly rounded to nearly straight.

726 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Lateral margins nearly straight to convex; anterolateral extremities strongly
rounded. Surface marked by costellae of unequal size and narrow concentric
wrinkles best defined between the hinge and the posterolateral region.

Pedicle valve moderately convex with the greatest convexity in the anterior
half where the valve is gently geniculated. Umbonal region gently convex with
a gentle concave slope to the cardinal extremities. A low fold extends from beak
to front margin but is inconspicuous on geniculated portion. Midregion and an-
terior half of shell somewhat swollen. Cardinal extremities slightly deflected.
Interarea long, apsacline ; pseudodeltidium rudimentary.

Brachial valve gently concave in the posterior two-thirds but geniculated
toward the brachial valve in the anterior third. Greatest concavity located just
posterior to the geniculated part of the valve. Shallow median depression extend-
ing from the beak to geniculated part. Lateral regions of valve gently concave,
becoming less concave toward the cardinal extremities. Umbo concave. Inter-
area short, hypercline.

Interior of pedicle valve with large callosities in front of the diductor-adjustor
fields, well-developed pallial sinuses and well-defined genital impressions. In-
terior of brachial valve with high, thick median septum, large cardinal process,
and thick but short lateral septa.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Higlotyne et vcicve! shee. zeenies x 13.0 11.5 22.7 25.0 28
Paratype (pedicle valve 117401a)... 13.0 2 23.0 21.4 ?
‘ (brachial valve 11740I1b).. ? 14.5 26.4 23.3 ?

Types.—Holotype: 117401z; figured paratypes: 117401b,d,e,h,k,m,n,p,q,v ;
unfigured paratypes: 117401a,c,f,g,i,j,l,o,r-u,w-y.

Horizon and locality.—Lincolnshire formation (8 feet below Cybeloides bed)
in Virginia: Tumbling Run section, 14 miles southwest of Strasburg, Strasburg
(15’) Quadrangle.

Discussion—The specimens on which this species is based were etched from
limestone and are quite coarsely silicified; consequently, some of the details are
obscured. The pallial markings and septa of the interior, however, are well pre-
served, but the finer granulation of the internal surface and the finer costellae of
the exterior are not retained in detail. On the best-preserved exterior of a
brachial valve it is possible to count 6 fine costellae between the stronger ones
which are about I mm. apart about one-third the distance from the anterolateral
margin.

This species is closest to Sowerbyites triseptatus (Willard) but is larger and
less convex in its mature stages. In old shells the front third to half of the
pedicle valve is geniculated toward the brachial valve. The front quarter or
third of the brachial valve is geniculated and thickened. Specimens of the
pedicle valve of S. gildersleevei comparable in size to the type specimens of
S. triseptatus are less convex than the latter but have more widely divergent and
larger diductor-adjustor scars in the pedicle valve. Brachial valves of S. gilder-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 727

sleevei are less strongly geniculated than the type brachial valve of Willard’s
species.

SOWERBYITES HAMI Cooper, new species
Plate 181, C, figures 19-33

Small for the genus, wider than long with the length about two-thirds the
width at the hinge; cardinal extremities auriculate and forming an acute angle;
sides gently rounded and sloping slightly toward the middle; anterior margin
broadly rounded. Entire surface covered by very fine lamellae; larger costellae
numbering about 2 to the millimeter at the anterior margin. Posterior margin
with more or less well developed oblique wrinkles.

Pedicle valve evenly and gently convex in lateral profile and with the maximum
convexity at about the middle ; anterior profile broadly and gently convex. Umbo
swollen, the swelling merging with that of the median region; flanks gently con-
vex and sloping gently to the margins; anterior slope somewhat shorter and
steeper than the lateral slopes. Interarea long and gently apsacline.

Brachial valve most deeply concave in the median region from the umbo nearly
to the front margin; flanks gently concave; cardinal extremities somewhat
flattened.

Interior of pedicle valve with little or no development of the callosities anterior
to the diductor scars. Interior of brachial valve with low median septum and
moderate development of the inner pair of septa; outer pair not well developed
or absent.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
PROIOLYBE), vane st\- 05sec es oa ae 0.2 8.6 14.1 14.8 2.0
Paratype CIIZ4A0OCy) Io.) ss ees 7.5 7.0 EY / 11.5 1.8
Wd CET7AOGL) IRE. 8.6 7.9 11.5 12.4+- 1.9

Types.—Holotype: 117400a ; figured paratypes: 117400b,d-f; unfigured para-
types: 117400¢,g-j.

Horizon and locality —Bromide formation (Pooleville member) in Oklahoma:
From the shale beds immediately below the “Bromide dense” bed opposite the
road leading to the abandoned village of Gilsonite; in the road cut on the east
side of the section line road 1,300 feet south of the northwest corner of sec. 23,
TS. KR: 3 E., Murray County.

Discussion.—This species is characterized by its small size, moderately auricu-
late cardinal extremities, poorly developed outer lateral septa inside the brachial
valve, and poorly developed callosities at the anterior ends of the diductor scars
of the pedicle valve. Small size distinguishes this species from other described
species of Sowerbyites. The modest projections on the cardinal extremities are
unlike those of young S. triseptatus which are often mucronate. Young stages
of S. lamellosus, as indicated by growth varices, seem to have been more trans-
verse shells than the adult S. ham.

728 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

SOWERBYITES LAMELLOSUS Cooper, new species
Plate 180, C, figures 17-25; plate 181, B, figures 10-18; plate 184, G, figures 23-27

Shell of about usual size for the genus, length about two-thirds the width;
hinge equal to or forming the greatest shell width; lateral margins nearly straight
in the posterior half; anterolateral margins well rounded; anterior margin
broadly rounded to truncated. Cardinal extremities varying from a right angle
to acutely angular and subalate. Surface of exfoliated specimens costellate, with
about 12 of the larger costellae occupying a space of 5 mm. at the anterolateral
margins and 4 to 8 of the finest costellae occupying the spaces between the larger
ones. When not exfoliated the shell is covered by extremely fine lamellae which
are longest at the geniculated portion or anterior third of the pedicle valve.
Lamellae of brachial valve not well developed.

Pedicle valve varying from gently convex to moderately convex in lateral pro-
file with the greatest convexity at about the anterior two-thirds. Umbonal region
slightly inflated with the slopes to the cardinal extremities gentle; anterolateral
slopes steep; anterior slope steep. Interarea gently apsacline to orthocline.
Pseudodeltidium short. When the lamellae of the exterior are present, the steep-
ness and narrow convexity of the anterior third are emphasized.

Brachial valve gently concave in lateral profile with the greatest concavity lo-
cated at the anterior third where the valve is somewhat sharply bent toward the
brachial valve. Posterior two-thirds nearly flat but with a faint median sulcus
originating at the beak and extending to the front margin in some specimens.
Interarea short, hypercline. Cardinal extremities slightly deflected toward the
pedicle valve. Exterior lamellae shorter and not so well developed as in the
pedicle valve.

Interior of pedicle valve with outside margin of muscle area forming a right
angle. Adductor impressions deeply sunk and located within the delthyrial cham-
ber. Adjustor-diductor scars straight with outer margins slightly rounded, ex-
tending slightly anterior to the middle of the valve. Anterior callosities moder-
ately thick.

Interior of brachial valve with low, rounded, thick median septum and 2 low
but wide lateral septa, the inner lateral septum being the stronger of the two.
Cardinal process moderately elevated ; callus deposit about the cardinalia thick.
Anterior slope steep ; anterior end of median septum only slightly elevated.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PAGIOUV OE nic gticnn eRe ees adinve 13.8 12.8 18.9 19.7+ 4.9
Paratype’ (TI74G3a) s'. caes tye 13.3 12.0 21.3 22.8 2.8
m (LE7AOSA) SS. oe 13.4 12.7 22.9 23.9-++ 3.0
Se (BIAAOSC) 04 i. BSS 12.5 11.6 2r5 212 28
‘ CEIFAOGE a cha s stirs scase 13.1 12.8 21.6 22.7+ 3.9

Types—Holotype: 117406c; figured paratypes: 117402a-c,h, 117403a-c,
117405a-d ; unfigured paratypes: 117402d-g, 117406a,b,d,e.
Horizon and locality—Bromide formation (Mountain Lake member) in Okla-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 729

homa: From bed 22 of Decker west of U. S. Highway 77, NE# sec. 25, T. 2 S.,
R. 1 E., north of Ardmore, Carter County; in reef limestone on the west side
of the cut on Oklahoma Highway 18, 1.8 miles south of Sulphur, Murray
County ; sec. 20, T. 6 N., R. 15 W., north side of Wichita Mountains; 25 to 46
feet above the Bromide sand on Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray
County ; West Spring Creek, east of Pooleville, Murray County; 150 feet below
the top at the hairpin bend 0.1 mile below the Observation Point on the Scenic
Drive, 1 mile east of U. S. Highway 77, center NW4INW3 sec. 29, T. 1 S., R. 2
E., Murray County.

Yellow shaly limestone just above a 25-foot bed of sandstone at base of the
Eureka group in Nevada: In the saddle just north of hill 8167, Martins Ridge,
Monitor Range, Roberts Mountains (1°) Quadrangle.

Doubtfully referred to this species are specimens from the Sevier formation in
Tennessee: In a ravine on Tennessee Highway 73, 0.3 mile south-southeast of
Walker Chapel, Kinzel Springs (T.V.A. 148-NE) Quadrangle; on Tennessee
Highway 71 (Chapman Highway) 1.58 miles east-northeast of Cusick, Walden
Creek (T.V.A. 156-SW) Quadrangle.

Discussion.—This species as here described is somewhat variable, but it is
especially characterized by its transverse form, large size, and subrectangular out-
line. It is most like S. triseptatus from which it can be distinguished by the
generally wider shells with more nearly rectangular cardinal extremities in the
young. Inasmuch as S. triseptatus and S. lamellosus are both variable species,
some specimens of each resemble the other markedly. Narrow individuals occur
in both species, but the prevailing tendency is for the Oklahoma and Nevada
specimens to be wider than the Tennessee and Virginia ones. Sowerbyites
lamellosus is generally a smaller species than S. gildersleevei and does not attain
the elaborate development of the interior seen in that Virginia species. The cal-
losities at the front of the diductors are much stronger in the Virginia shells
than in the Oklahoma ones.

Three lots of Sowerbyttes from the Sevier formation of East Tennessee have
been placed tentatively in this species. The specimens are not well preserved as
they occur in a fine-grained sandstone and their exteriors are exfoliated. They
do, however, have the somewhat transversely rectangular form of the Oklahoma
and Nevada specimens and seem to occupy a somewhat post-Lincolnshire
horizon.

SOWERBYITES SUBNASUTUS Cooper
Plate 182, A, figures I-11

Species of about medium size for the genus, semielliptical in outline. Hinge
forming the greatest shell width; cardinal extremities alate. Anterior margin
somewhat narrowly rounded; lateral margins sloping obliquely anteromedially.
Surface ornamented by costellae of unequal size ; 9 of the larger costellae occupy
a space of 5 mm. at the front of the holotype. Short concentric lamellae also
present on the exterior.

7309 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve most strongly convex in the anterior third where the valve is
strongly geniculated toward the brachial valve. Anterior slope moderately long
and steep. Posterior two-thirds slightly convex. Umbo slightly swollen; beak
small, protruding slightly posterior to the posterior margin. Median region
slightly folded, but the fold is lost where the valve is geniculated. Lateral slopes
moderately steep; interarea long for the genus, slightly curved, approximately
orthocline. Pseudodeltidium small.

Brachial valve concave with the greatest concavity at the place of genicula-
tion. Umbo concave; median sulcus shallow and poorly to well defined; areas
bounding sulcus nearly flat or concave. Cardinal extremities sulcate. Interarea
hypercline. Chilidium short.

Interior of pedicle valve with elongate diductors terminating in low callosities
located at about the middle of the valve. Interior of brachial valve with promi-
nent median septum highest at about the middle of the valve, lateral septa well
developed, the inner 2 the stronger.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
EIOIGEY OE ca sce eae cn sree ean 12.1 10.6 15.0 17.2+ 3.9
Paratype (111797d).......... 10.3 8.6 15.2 17.74 3.2
3 COSrS 7a) ss To 10.6 9.0 16.3 18.2 2.9
rf (1174072) oe pices lescwe 10.5 9.2 13.8 16.1+ 2.4

Types.—Holotype: 111797g; figured paratypes: 98187a-c, 111797a,d,f; un-
figured paratypes: 111797b,c,e,h, 117407a-d.

Horizon and locality—Lincolnshire formation in Virginia: In Marcem
Quarry, 2 miles west of Gate City, Gate City (T.V.A. 188-NE) Quadrangle.

Discussion—This species is distinguished by its medium size, strong con-
vexity of the pedicle valve and consequent deep concavity of the brachial valve,
and the somewhat narrowly rounded anterior margin. It is smaller and deeper
than S. triseptatus, S. lamellosus, and S. gildersleevei. Its size is similar to that
of S. delicatus, but it is much more convex.

SOWERBYITES TRISEPTATUS (Willard)
Plate 160, B, figures 10-12; plate 180, A, figures 1-13; plate 182, B, figures 12-29;
plate 183, B, figures 17, 18; plate 200, B, figures 4-7
Plectambonites triseptatus Wr1LLarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
pl. 2, figs. 7, 8, 1928.

Shell of about usual size for the genus, subsemicircular in outline with the
width at the hinge nearly twice the length. Cardinal extremities acutely angular
to auriculate. Lateral margins gently rounded, more or less sloping in an antero-
median direction. Anterior margin moderately strongly rounded to only gently
rounded. Surface marked by concentric undulations, scalloped on their edges.
These undulations are formed by thin shell lamellae concentrated on the surface,
and the scallops are produced by the undulation of the lamellae over costellae
underneath. On the surface the costellae appear as depressed lines or radial

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 731

grooves in the lamellae. Where the lamellae have been stripped off, the orna-
mentation consists of fine and strong costellae. About 11 strong costellae occupy
a space of 5 mm. at the front, and from 3 to 7 fine costellae occupy the space be-
tween the stronger ones. A few specimens with oblique wrinkles along the
posterior margin.

Pedicle valve only slightly convex in the young but becoming moderately con-
vex in lateral profile in old shells. Greatest convexity just anterior to the middle.
Anterior slope somewhat steeper than the posterior one. Umbonal region a little
inflated, beak not prominent but protruding very slightly posterior to the pos-
terior margin. Posterolateral slopes gently concave and moderately steep. Inter-
area apsacline, slightly curved.

Brachial valve gently concave with the greatest concavity in the anterior third
or half. Umbo sulcate, sulcus poorly defined to about middle of valve where it
is lost; cardinal extremities sulcate; interarea short, hypercline; lateral areas
gently concave.

Interior of pedicle valve with moderately strong callosities at the anterior ends
of the diductor scars and located at or slightly anterior to the middle. Interior
of brachial valve with strong median septum and well-developed lateral septa.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Hypotype (117415g)......... Tr2 10.0 17.4 21.0 22
i (itT4068)) 0a. 3 12.6 5 17.5 17.8+ 2.8
bf ( TEEAGGE A, 80). 5 fk 9.9 8.7 13.4 14.8+ 2.3
c (UI74008 beni oO. ..% 10.5 9.6 17.0 18.9+ 2.8
os EE ZAC 2, 8 ias8 13.2 II.9 19.9 23.0 ?

Types.—Figured hypotypes: 111796a-c,e,f, 117409a-c,e, I17410a, I17411Ib,
117412b, 117413a,b, 117414a-c, 117415a,b,e,¢,i,j, 123252a,b; measured hypotypes
111496a,f.

Horizon and locality——Lincolnshire formation in Virginia: Near Goodwins
Ferry on New River, Giles County ; 1,000 feet north of road along Buffalo Creek,
24 miles west of Murat, Rockbridge County; at the Dunkard Church, 6 miles
north of Buchanan, Natural Bridge Special (15’) Quadrangle; 1.8 miles S. 4°
W. of Bethel Church, 5.9 miles due east of Harrisonburg, Harrisonburg (15’)
Quadrangle; 4 mile northeast of the junction of Virginia County Highways 602
and 725, Augusta-Rockbridge County line.

Same formation in Tennessee: In Clinch Valley, 0.2 mile southwest of Shiloh
Church, near the center of the northwest subquad., Pressmens Home (T.V.A.
171-NE) Quadrangle ; # mile southwest of Mount Eager Church, Hogskin Val-
ley, Powder Springs (T.V.A. 154-SW) Quadrangle; 90 to 120 feet above the
“Mosheim” limestone on U. S. Highway 25E, 1 mile north of Indian Creek,
Howard Quarter (T.V.A. 162-NW) Quadrangle; on U. S. Highway 25E north
of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle; 4 mile north of Eidson,
Kyles Ford (T.V.A. 170-SE) Quadrangle; at Red Hill north of road 44 miles
west-southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle.

732 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Lincolnshire formation (Hogskin member) in Tennessee: On Sally Cleveland
Farm, $ mile southwest of Washburn Station, Dutch Valley (T.V.A. 154-SE)
Quadrangle; at the bend of the road, Red Hill, 44 miles west-southwest of Thorn
Hill, Avondale (T.V.A. 162-SW) Quadrangle; on U. S. Highway 25E just
south of the first bridge north of Thorn Hill, Avondale (T.V.A. 162-SW) Quad-
rangle; 2 miles southwest of Hall Crossroad, Fountain City (T.V.A. 146-SW)
Quadrangle; south side of the school at Chesney, Luttrell (T.V.A. 155-NW)
Quadrangle; 1 mile southeast of Washburn, Dutch Valley (T.V.A. 154-SE)
Quadrangle; in Maloneyville, John Sevier (T.V.A. 146-SE) Quadrangle; Lee
Valley, Lee Valley (T.V.A. 171-NW) Quadrangle; Clinchport, Clinchport
(T.V.A. 188-NW) Quadrangle.

Discussion.—This is a very variable species as described herein. It is possible
that more extensive collections will indicate further separations of geographi-
cally restricted forms, but the available collections will permit no such splitting.
This species is characterized by its large size, generally alate cardinal extremi-
ties, at least in youthful forms, and the strong but not extravagant development
of internal features. This species is smaller and usually more convex than S. gil-
dersleevei and larger and less convex than S. subnasutus. The species is most
like S. lamellosus but differs in having less transverse shells and generally more
acute cardinal extremities. Some variants of each species resemble each other,
but the majority of specimens of each species indicate the more transverse form
and more rectangular outline of the western species.

Numerous specimens of Sowerbyites occur in the Hogskin shale and in thin,
argillaceous limestones associated with the shale. These Hogskin forms are often
more transverse than some of the specimens etched from Lincolnshire limestone.
These, however, appear to be end members of the species. These wide forms
are generally more acuminate on the cardinal extremities than S. lamellosus.
They are also linked to the somewhat narrower limestone specimens by inter-
mediate forms.

SOWERBYITES sp. 1

Of considerable interest in the stratigraphic and geographic distribution of
this genus is its presence in the Quebec City formation. A single pedicle valve
obtained from Dr. R. Bureau, Laval University, Quebec, indicates the species
represented to be similar to S. triseptatus but not so transverse and somewhat
rectangular on the cardinal extremities. In lateral profile the greatest convexity
is at about the middle and the anterior slope is long and steep, its length about
equal to that of the body of the shell. The angle of geniculation is about 100°.

Measurements in mm.—123300, length 14.4, surface length 17.0, midwidth
22.7, hinge width 23+, height 4.4.

Described specimen.—123300.

Horizon and locality. Quebec City formation (Mountain Hill conglomerate)
in Quebec, Canada: 400 to 500 feet south of Morin Building, Mountain Hill,
Quebec City.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 733

Subfamily IsopHRAGMINAE Cooper, new subfamily

Small, resupinate, costellate shells having an exterior like Palaeostrophomena
but with 2 long, parallel septa in the brachial valve.

ISOPHRAGMA Cooper, new genus

(Greek isos, equal; phragma, fence)

Shell small, usually wider than long with the hinge equal to or forming the
greatest shell width. Resupinate; anterior commissure uniplicate ; brachial valve
sulcate in umbonal region, usually plicate in anterior half. Surface multicostel-
late ; pseudopunctate.

Pedicle interior with small, stout teeth, having deep fossettes on their inner
face ; dental plates short and stout, usually obsolete because of filling of umbonal
cavities by adventitious shell substance. Delthyrial cavity moderately deep; del-
tidium narrow and short. Sides of delthyrial cavity with marginal thickenings ;
interarea long, apsacline. Muscle field with elongate and narrow diductor impres-
sions and small obscure adjustor impressions. Adductor track wide. Pallial
trunks strongly marked, major trunks extending anteriorly from diductor impres-
sions, one branch extending anteromedially, and another laterally. A second
major trunk is given off laterally from near the ends of the dental plates and ex-
tends by a narrow curve anterolaterally. Several large callosities are located just
within the anterior and lateral margins.

Brachial interior with short brachiophores and much thickened notothyrial
platform. Sockets deep, brachiophores moderately large, flattened plates sup-
ported by lateral thickenings of the notothyrial platform. Cardinal process large,
simple, situated on the posterior face of the notothyrial platform and in old shells
produced forward as a ridge along the surface of the platform. Myophore car-
inate. Anterior to the notothyrial platform 2 subparallel ridges extend anteriorly
nearly to the front margin. These ridges rise to a crest at a point slightly anterior
to or nearly at the center of the valve. Ridges often greatly thickened and the
space between them filled by excess shell substance. Adductor impressions lo-
cated on each side of the median ridges ; the posterior adductor scars the larger.
Pallial impressions strong; 2 main trunks originating at the anteromedian ex-
_ tremities of the anterior pair of adductor impressions and extending anteriorly,
bifurcating near the margin; a second pair of trunks extending anterolaterally
from the line of contact of the anterior and posterior adductor scars; a third pair
extending laterally from the posterior ends of the posterior adductor scars. Inter-
area hypercline.

Genotype.—Isophragma ricevillense Cooper, new species.

Discussion.—A casual study of these interesting shells suggests that the genus
is a reversed Sowerbyella or Leptelloidea. Although the contour of the valves is
reversed from that of the genera named, a sufficient number of internal structural
differences between Isophragma and Sowerbyella and Leptelloidea are at once
apparent and serve to distinguish the genera. Aside from its resupinate form,
Isophragma is characterized by the strong subparallel lamellae forming the axis

734 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

of the brachial valve. Inside the pedicle valve the musculature is quite orthoid.

Isophragma differs from Sowerbyella in several important features. Inside
the pedicle valve of Sowerbyella a short but prominent median septum located at
the posterior of the valve divides the muscle field. Furthermore, the arrangement
of the muscles is not the same as in Jsophragma. Inside the brachial valve the
notothyrial platform of Isophragma is not excavated under the cardinal process
as it is in Sowerbyella, and the brachial processes are somewhat longer in the
latter genus. Again in Sowerbyella the arrangement of the adductor scars of the
brachial valve is not so orthoid as in Jsophragma.

Leptelloidea and Leptella differ from the genus under discussion in the pos-
session of an elevated visceral disk which is completely absent in Isophragma.

In the United States this genus has a moderately long stratigraphic range from
the Arline formation of the Knoxville area into the Benbolt formation. Although
this is a rather extensive stratigraphic range, no species is known between the
intervals named. In Great Britain Leptella? pseudoretroflexa Reed from the
Llandeilo (Balclatchie formation) belongs to this genus.

ISOPHRAGMA BISEPTATUM Cooper, new species
Plate 171, D, figures 20-29; plate 171, E, figures 30-32

Large for the genus, wider than long, with the greatest width at the hinge.
Cardinal extremities varying with age from alate to approximately a right angle.
Anterior margin broadly to narrowly rounded; lateral margins obliquely straight
to slightly concave. Surface of an adult marked by about 75 narrowly rounded
costellae having interspaces about the same width as the costellae. Growth
lamellae strong, costellae often produced into short, blunt spines at the growth
lamellae. Costellae crossed by minute elevated fila, at least 15 to 20 to the
millimeter.

Pedicle valve nearly flat in lateral profile, umbo slightly swollen, the swelling
extending forward as a low fold for one-fourth to one-third the length. Valve an-
terior to the fold flattened or slightly depressed to form a shallow sulcus, in some
specimens the swelling continuing as a fold to the front margin. Tip of beak
smooth and convex. Anterior and anterolateral portions of the adult very gently
convex and with the cardinal extremities deflected slightly toward the brachial
valve. Beak extended slightly beyond the posterior margin. Interarea broad and
long, strongly apsacline. Deltidium long and narrow.

Brachial valve unevenly convex in lateral profile with the posterior third flat-
tened or concave and the anterior two-thirds gently to moderately convex ; gently
convex in anterior profile. Umbo concave, the concavity a shallow pit just an-
terior to the posterior margin. Concavity extended anteriorly as a narrow and
shallow sulcus for a short distance only or nearly to the front margin in young
or middle-aged shells. Anteromedian region gently swollen; anterolateral areas
gently convex with moderate slopes to the depressions defining the cardinal alae.
Interarea shorter than the pedicle one, moderately long and hypercline in position.

Interior of pedicle valve with muscle area about as long as wide, with square

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 735

anterior margin, deeply impressed and narrow diductor impressions, and wide,
shallow adductor field. Delthyrial cavity filled with callus; anterior portion of
muscle area thickened and elevated. Visceral region much thickened and with
many oblique subperipheral ridges.

Interior of brachial valve with thickened median septum rising to a sharp
crest near the middle of the valve and composed of 2 nearly parallel septa
cemented together by shell material. Adductor impressions short and narrow,
deeply impressed.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
ELOLOUV DEY GRO ee aes NE 10.5 9.4 Tst7. 14.7 3.4
Paratype, «GLLOOOS))) cyt. sty aed « Gy2 0.6 ? 12.2 13.0 1.8
as GETOOOSE ))i5.4:< nps,0'e sexes 8.4 7.4 11.8 14,1 3.0
Hi REPOOOSE)) ogee s.s 5 aides 2 7.4 10.7 13.0 ?

Types.—Holotype: 110905a; figured paratypes: 110go5b-d, 1173738,
117374a,b; unfigured paratypes: 110904, 117373b.

Horizon and locality.—Benbolt formation in Virginia: At 4o feet above the
base, + mile southeast of Green Valley Church, 3 miles southwest of Lebanon,
Brumley (T.V.A. 205-SE) Quadrangle; 4 mile northeast of Speers Ferry,
Clinchport (T.V.A. 188-NW) Quadrangle; 0.2 mile south of the middle fork
of Moccasin Creek, 14 miles south of Hansonville, Hansonville (T.V.A. 205-SW)
Quadrangle.

Botetourt formation in Virginia: On the south side of U. S. Highway 60,
1 mile northwest of Lexington, Lexington (15’) Quadrangle; at the junction of
Virginia Highways 731 and 724, 2 miles northwest of Brownsburg, Lexington
(15’) Quadrangle.

Arline formation in Virginia: Quarry at Marion, Marion (T.V.A. 218-SE)
Quadrangle.

Discussion.—This species differs from other known Appalachian species by
its relatively greater length, length/width ratio varying from 0.70 to 0.85. The
brachial interior is somewhat less thickened and the callus swelling about the
median septa much less developed than in J. ricevillense which most nearly ap-
proaches this species in size. This Benbolt species will not be confused with the
Arline I. extensum which is a quite slender form usually of small size. The
I. subabbreviatum again is smaller and possesses a median structure much more
highly elevated in the direction of the pedicle valve than that of J. biseptatwm.

ISOPHRAGMA EXTENSUM Cooper, new species

Plate 170, C, figure 17; plate 170, D, figures 18-29; plate 171, A, figures I-14;
plate 171, C, figures 16-19; plate 184, F, figures 19-22

Shell of about medium size for the genus, nearly twice as wide as long at the
hinge and with the hinge forming the widest part. Cardinal extremitites acute
to alate. Front margin broadly rounded to truncate. Surface marked by costellae
of unequal size; 2 to 4 of the smaller costellae occupy the space between the

730 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

larger ones; about 16 costellae occupy a space of 5 mm. at the front of a valve
about 6 mm. long.

Pedicle valve flat to slightly concave in lateral profile ; beak slightly projecting
posterior to the posterior margin; umbo narrow, slightly swollen and produced
forward as a narrow, low fold which may or may not disappear at about the mid-
dle of the valve. Anteromedian portion anteriorly depressed to form a shallow,
wide sulcus. Area bounding sulcus slightly folded; lateral areas nearly flat to
concave. Interarea moderately long, apsacline.

Brachial valve with sulcate umbo; sulcus extending nearly to middle of valve;
anteromedian half of valve undulated into a broad fold; lateral areas slightly
convex and with steepening slopes toward the margins. Area in front of cardinal
extremities sulcate. Interarea moderately long but shorter than the interarea of
the pedicle valve, hypercline.

Interior of pedicle valve well thickened; delthyrial cavity small, choked with
excess shell at the apex; ridges between pallial impressions thick; surface cov-
ered by small granules.

Interior of brachial valve with paired septa extending nearly to the front mar-
gin but with the crests of the septa at about the middle of the valve ; adductor field
small, surrounded posterolaterally by narrow ridges. Radial thickenings between
pallial impressions moderately strong.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness

Eiolotypels «iced... 2: 7.8 6.6 12.8 14.8 2.2
Paratype (FL7370D ) hes. « tier ened 6% 7.0 5.9 10.0 12.3 28
vi CPIOQOOA) ethane sacn ne 7.4 6.7 11.2 14.1-+ 2.4

Types.—Holotype: 117376a; figured paratypes: 110908a,b-d,g,h, rI10goga,
I1ogiia,d, 110912, 117375, 117376c-f,k,1; unfigured paratypes: 110908e,f,
11ogogb, 11091Ib,c, 117376b,g-j,m,n.

Horizon and locality——Arline formation in Tennessee: 100 yards southwest
of the Negro Cemetery, 4 mile northeast of center of Friendsville; glade 4+ mile
southeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle; 1,500 feet
south of Burnett Creek, Shooks Gap (T.V.A. 137-NE) Quadrangle.

Arline formation in Virginia: Near entrance to Porterfield Quarry, 5 miles
east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Little Oak formation in Alabama: At junction Bailey Gap road and Cahaba
Valley road, SWiSW3 sec. 13, T. 19 S., R. 2 W., 13 miles northeast of New-
hope Church, Vandiver (15’) Quadrangle.

Discussion.—This species is characterized by its great width along the hinge
as compared to its length. Furthermore, the cardinal extremities are acutely an-
gular even in the adult form, thus differing from J. biseptatum. From I. ricevil-
lense this species differs in its more acute cardinal extremities, greater width, and
less even character to the costellae.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER WAY

ISOPHRAGMA PONDEROSUM Cooper, new species
Plate 210, H, figures 25-32

Large for the genus, subrectangular in outline; sides rounded, somewhat
oblique; anterior margin broadly rounded; cardinal extremities acute; anterior
commissure rectimarginate. Costellae strong, numbering 13 to 14 in 5 mm. at
the front margin.

Pedicle valve nearly flat in lateral and anterior profile; beak low; umbo nar-
rowly rounded and extended to about the middle as a low fold; anterior half
slightly depressed to form a barely perceptible sulcus ; sides bounding fold slightly
concave on each side of the fold but becoming flat on the lateral extremities.
Interarea moderately long, strongly apsacline; deltidium narrowly rounded.

Brachial valve faintly convex in lateral and anterior profiles; umbo sulcate,
the sulcus extending to about the middle; anterior third gently swollen to form
a barely perceptible fold. Flanks bounding sulcus gently convex. Interior with
septa united into a broad ridge rising to a crest at its free extremity slightly
anterior to the valve middle.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness

Piglotvine bs o).ca «\aeeeyd <in:c\e 0.0 Bemseis 10.7 9.9 13.6 ? 14.6-++ 2.9
Paratype'r (1232012... 3 s<c00 ss 0.4 ? 14.8 173 ?
a (8232698) si6i.'ss Wa's.00 11.6 ? 15.8 16.4-++ ry

Types.—Holotype: 123259a; figured paratypes: 123261, 123262a; unfigured
paratypes: 123259b, 123262b.

Horizon and locality. Y ellow-weathering limestone on 25-foot sandstone at
base of Eureka group in Nevada: 2 and 3 miles north of Martin Ranch, Roberts
Mountains (1°) Quadrangle.

Discussion.—This is the largest species of the genus known. Like most of the
other species the young stages are very transverse, but in this western form the
cardinal angles tend to become less obtuse as adulthood and old age are reached.
This species is suggestive of I. biseptatum but differs, besides its size, in being
more elongate, having a flatter brachial valve and a more apsacline interarea.
The Nevada species is much less transverse than J. ricevillense, is not so strongly
sulcate, has a less pronounced brachial fold and a more apsacline interarea.

ISOPHRAGMA RICEVILLENSE Cooper, new species
Plate 170, A, figures I-15

Shell large for the genus, wider than long and with the hinge forming the
widest part of the shell ; cardinal extremities varying from a right angle to acute;
anterior margin broadly rounded. Valves subequal in depth, the brachial valve
having a slightly greater depth than the pedicle one. Surface marked by subequal
narrowly rounded costellae, about 14 in the space of 5 mm. at the front of a valve
7mm. long. Two generations of costellae intercalated between the primary ones.

Pedicle valve flat or slightly concave in lateral profile; umbo slightly swollen ;

738 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

folded portion of umbonal region short ; front half of valve gently concave ; lateral
regions nearly flat ; extremities deflected slightly toward the brachial valve. Inter-
area moderately long, apsacline.

Brachial valve forming a gentle sigmoidal curve in lateral profile; umbonal
region narrowly sulcate, sulcus shallow, noticeably extending to the middle of
the valve and more indistinctly extending nearly to the front margin; anterior
half gently swollen and folded in anterior profile to correspond to concave por-
tion of the pedicle valve. Lateral areas flattened to gently concave; interarea
hypercline, short.

Interior of pedicle valve only slightly thickened in the young but with large
subperipheral callosities and deeply intrenched pallial marks in old shells. In-
terior of brachial valve with septa short and elevated to a crest at about the
middle. Adductor impressions deep.

Measurements in mm.—

Brachial Hinge Thickness
Length length Width width
TA GIGI DE aie iameraie «oo hveibass,e's 00-018 8.4 7.2 12.0 13.3 2.4
Paratype (pedicle valve 110923a)... 7.6 ? 10.7 14.0 ?
5 i ae © 'TTOO2SD) 4.0, (8.0 ? 12.7 13.9 ?
a Gir? Sah Groo2sh)ia..° 5:0 ? 8.8 9.6 ry
rs (brachial valve 110923c).. 8.4 ? 10.2 11.5 r
vs Geir’ ‘oh prog2gn ie. 7B ? 11.9 12.5 ?
ey (08 “* 110923e).. 6.7 ? 12.0 14.7 ?
¢ fo ae oy RTOOZO)...<'.. 78 7.0 11.7 13.0 2.1

Types.—Holotype: 110918a; figured paratypes: 110923a-d,g; unfigured para-
types: I110918b, 110920, 110923¢e,f.

Horizon and locality—Base of Athens formation in Tennessee: Just east of
intersection, 24 miles southeast of Riceville, Calhoun (T.V.A. 125-SW) Quad-
rangle; 660 feet S. 40° E. of the railroad intersection 1 mile north of Athens,
Athens (T.V.A. 125-SE) Quadrangle.

Discussion.—Isophragma ricevillense attains a fairly large size for the genus
and differs from J. biseptatum in size and thickness of shell, a lesser develop-
ment of the median ridge, and more clearly defined pallial impressions. It differs
from I. extensum in a lesser development of cardinal extremities and somewhat
coarser and more even development of the costellae.

ISOPHRAGMA SUBABBREVIATUM Cooper, new species
Plate 169, A, figures 1-9

Shell slightly wider than long, subrectangular in outline; valves thick. Cardi-
nal extremities in the young acutely angular but forming nearly a right angle
in the adult. Front margin subtruncate; anterolateral margins broadly rounded ;
lateral margins oblique. Surface multicostellate, 7 costellae occupying a space
of 2 mm. at the front of the holotype. Costellae nearly equal in size.

Pedicle valve with a moderately strong but narrow fold extending from the
beak nearly to the front margin. Front third of valve depressed into a broad,

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 739

shallow sulcus occupied by about 16 costellae. Lateral areas bounding sulcus
slightly convex, depressed below the median fold. Interarea long, apsacline.

Brachial valve with a shallow, narrow sulcus originating at the beak and ex-
tending distinctly for slightly more than half the length where it becomes
shallower and passes into a broad gentle fold. Lateral areas convex except near
the posterior margin where they are slightly sulcate. Anterolateral slopes mod-
erately steep. Interarea moderately long, hypercline.

Interiors of both valves greatly thickened and all structures enlarged. Del-
thyrial cavity partially filled by excess shell; subperipheral callosities often pon-
derous. Inside the brachial valve the median septa are welded into a single
spoonlike process highest at the center. Internal surfaces strongly granulose.

Measurements.—Holotype, length 6.3, midwidth 8.4, hinge width 8.2, thick-
ness 2.8.

Types——Holotype: 110916a; figured paratype: 110916b; unfigured para-
types: II0QI2, 110916c.

Horizon and locality—Arline formation in Tennessee: In glade 4 mile south-
east of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Discussion—lIsophragma subabbreviatum in outline and profile differs from
other known species. It is more quadrate than any known form, and the median
ridge is strongly and abruptly turned toward the pedicle valve.

ISOPHRAGMA SULCATUM Cooper, new species
Plate 170, B, figure 16

Shell small, planoconvex in lateral and anterior profiles, wider than long with
the hinge forming the greatest width ; cardinal extremities alate; anterior margin
truncated ; anterolateral extremities narrowly rounded; lateral margins nearly
straight, oblique. Surface multicostellate, costellae of unequal size, about 3 to 4
in a millimeter at the front margin.

Pedicle valve with low narrow median fold and slightly convex flanks ; inter-
area long, apsacline. Brachial valve deeply sulcate at the umbo with sulcus ex-
tending to the front margin, narrow and moderately deep throughout its length.
Sides of shell nearly flat. Interarea procline. Brachial interior with septa nearly
reaching the front margin.

Measurements in mm.—Holotype, length 5.9, brachial length 4.8, width 18.7,
hinge width 11.6, thickness 1.4.

Type.—Holotype: 110917.

Horizon and locality.—“Lenoir” formation (lowest beds with Christiania just
above the Lenoir [with Maclurites] and below the Pratt Ferry formation) in
Alabama: 0.15 mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species differs from others herein described by its flat and
deeply sulcate brachial valve. The single known specimen shows also the 2
median septa as shallow, slightly divergent plates extending almost to the front
margin. In this respect the species differs from other known forms in which the
median septa extend scarcely beyond the middle of the valve.

7490 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

ISOPHRAGMA sp. 1
Plate 213, B, figure 21

A small brachial valve, nearly plane in profile and with moderately strong
costellae, was taken in the residues from the Pratt Ferry limestone. The interior
shows the subparallel plates which in this specimen are somewhat thinner than in
other species. The discovery is interesting because Isophragma occurs below the
Pratt Ferry limestone in the upper part of the so-called Lenoir and also in the
contemporary Little Oak formation. This helps to emphasize the close relation-
ships of these various formations.

Figured specimen.—123286.

Horizon and locality Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Family TAPHRODONTIDAE Cooper, new family

Plectambonitacea having an exterior like Sowerbyella but the brachial valve
having orthoid cardinalia, thick notothyrial platform, high, bladelike cardinal
process, and long slender brachiophores. Median ridge formed of 2 subparallel
plates.

TAPHRODONTA Cooper, new genus
(Greek taphros, ditch; odont, tooth)

Shell small, about 4 inch in width; suggesting Sowerbyites or Sowerbyella in
appearance; pedicle valve gently convex; brachial valve concave ; anterior com-
missure rectimarginate; surface multicostellate ; pseudopunctate.

Pedicle valve with narrowly convex, fairly strongly elevated pseudodeltidium ;
delthyrial cavity moderately deep; dental plates short and stout; teeth flat, ob-
lique, double, the two processes separated by a deep, slitlike fossette ; muscle field
somewhat heart-shaped, the diductor scars wide and oval, the adjustor scars not
differentiated ; adductor scars small, located between diductors near center of
muscle field. Median area just anterior to muscle field thickened ; area anterior
to this median thickening forming a sulcus that extends to the anterior margin;
lateral areas bounding sulcus thickened and roughened, the thickening not reach-
ing the margins.

Brachial interior with thickened notothyrial platform filling or nearly filling the
notothyrium ; cardinal process a slender median ridge on the notothyrial plat-
form ; sockets deep; brachiophores long, bladelike, pointed distally but thickened
by an articulating boss opposite the point where the brachiophore joins the noto-
thyrial platform; median ridge anterior to notothyrial platform composed of 2
thick, united septa rising to a crest near the anterior margin; inner margin an-
terior to median septa thickened and extending as a thick, pustulose band cor-
responding to the marginal troughlike band of the pedicle valve.

Genotype.—Taphrodonta parallela Cooper, new species.

Discussion—The exterior features of this genus form an almost exact con-
vergence toward other genera in other geological periods. The most distinctive

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 741

feature of Taphrodonta is thus its interior characters. Inside the pedicle valve
the dental plates and articulatory apparatus are like those of Palaeostrophomena
and other Plectambonitacea. The muscle field is rather generalized and without
septa, at least in this species. Perhaps the most distinctive feature of the interior
of the pedicle valve is the thickening of the flanks of the shell on each side of
the median sulcus and posterior to the margin. This makes a raised or thickened
visceral area but a thin marginal zone. The latter evidently fits closely to the
thickened marginal zone of the brachial valve. The anterior shallow marginal
area is strongly pustulose.

The most striking feature of the brachial valve interior is the long median
ridge consisting of 2, or what appear to be 2, septa welded together to make a
broad ridge with an elevated margin on each side. This ridge is joined to the
notothyrial platform which carries a thin blade for a cardinal process. The
brachiophores are moderately long, their proximal ends buried in the tissue of
the notothyrial platform. Where the brachiophore protrudes from this tissue
it is thickened on the outside, the boss thus produced undoubtedly sharing in
the articulation of the valves. The distal end of the brachiophore is a short, sharp,
and thin crus like that seen in some orthids such as Hesperorthis.

Of especial interest in this genus is the marginal region of the brachial valve
which is considerably thickened and forms a steep slope that fits into the thinned
marginal area of the pedicle valve. Both areas, the thinned one of the pedicle
valve and the thickened area of the brachial valve, are strongly pustulose. In
opening, only a thin passage would result between the valves, the pustules form-
ing an effective type of strainer. This role for the pustules also may be seen in
the Productacea where it is developed to perfection.

The ensemble of characters in this genus are most suggestive of Jsophragma
which also possesses a median ridge very much like that of Taphrodonta. Despite
the similarities, strong differences may be detected. In the first place the exterior
of the two genera is unlike. Jsophragma has a reversed convexity to the brachial
valve. It is concave in the young but becomes convex anteriorly. In other words
the convexity is the reverse of that of Taphrodonta.

Inside the valves other differences may be seen between Taphrodonta and
Isophragma. The muscle field of the pedicle valve of the latter genus is wide,
extends to about the middle, and has elongate diductor scars, whereas this feature
of Taphrodonta is short and narrow. The teeth of Jsophragma seem to be more
simply constructed. Inside the brachial valve the median ridge shows its dual
origin more strongly in Isophragma than in Taphrodonta. Furthermore, the
brachiophores of Isophragma are short, flat blades and the cardinal process,
although simple, is inclined to be bulbous.

TAPHRODONTA PARALLELA Cooper, new species
Plate 165, A, figures 1-22

Small, semielliptical in outline with the hinge forming the widest part ; cardinal
extremities acutely pointed; sides moderately oblique, slightly rounded ; anterior

742 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

margin broadly rounded. Costellae narrowly rounded, distant, numbering about
3 to the millimeter at the anterior margin.

Pedicle valve unevenly convex in lateral profile, the posterior third to half
somewhat flattened but the anterior half moderately convex; anterior profile
broadly convex with the median ridge forming a somewhat obtusely angulated
crest. Umbo narrowly convex, the convexity produced anteriorly to about the
middle as a low and narrow fold which disappears in the somewhat swollen an-
terior ; flanks bounding fold slightly convex, gently depressed below the fold;
anterior third of median region and flanks gently bent and somewhat swollen to
form a moderately long and steep anterior slope. Interarea moderately long,
strongly apsacline.

Brachial valve gently concave in lateral profile and with the maximum depres-
sion just anterior to the middle and located at the sloping anterior face of the
inner median ridge. Umbo sulcate, the sulcus produced anteriorly nearly to the
anterior margin as a widening but shallow depression. Flanks bounding sulcus
nearly flat. Cardinal extremities flattened. Interarea short, anacline.

Measurements in mm.—Holotype, length 8.6, brachial length 8.0, midwidth
12.1, hinge width 13.7+, thickness 1.9, height 2.4.

Types.—Holotype: 117562e; figured paratypes: 117562b,f-i; unfigured para-
types : 117562a,c,d.

Horizon and locality—Upper Pogonip group in Nevada: In Ikes Canyon
1 mile above the entrance, Toquima Range, Roberts Mountains (1°) Quadrangle.

Discussion.—No other species of this genus is known to which this species may
be compared. The exterior form and profiles of the genus are like a number of
other genera. This genus on its exterior could be mistaken for Sowerbyites but
as far as known is not externally lamellose and has a flatter brachial valve than
the members of that genus. It might be confused with Palaeostrophomena, but
the members of that genus usually have convex brachial valves.

Family SYNDIELASMATIDAE Cooper, new family

Plectambonitacea having an exterior like that of Sowerbyella but cardinal
process simple and not fused to the brachiophores.

SYNDIELASMA Cooper, new genus

(Greek syn, together; di, two; elasma, plate)

Shell attaining 4 inch in width, thin, compressed, concavo-convex, semiellipti-
cal in outline; sowerbyelloid in profiles and general appearance; hinge forming
the widest part of the shell; cardinal extremities auriculate; ornamentation dis-
tantly costellate. Posterior margin with oblique wrinkles. Pseudopunctate.

Pedicle interior without dental plates; muscle area lightly impressed. Inter-
area short; pseudodeltidium much reduced or absent. Other details not known.

Brachial interior with sockets small, moderately deep, bounded by slender
brachiophores produced into thin, sharp points; cardinal process a short bulb
when viewed from the side of the pedicle valve; posterior of bulb marked by 3

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 743

septa; cardinal process covered by a narrow, convex chilidium; bulbous cardi-
nal process buttressed by a short shaft lying at the posterior termination of 2
thin, elevated septa which rise to their highest point near the anterior margin;
anterior ends of septa not thickened; inner margin not thickened; entire inner
surface marked by coarse granules especially well developed in the anterior parts
of the shell.

Genotype—Syndielasma biseptatum Cooper, new species.

Discussion.—This genus in its external form and profiles is most like Sower-
byella. It also resembles Sowerbyella in its interior characters but has a num-
ber of primitive features which separate it from that genus. The known speci-
mens of Syndielasma are not so concave as usual in Sowerbyella, and the shell
is much more compressed than is usual in that genus. The pseudodeltidium of
Syndielasma is much reduced and in this respect has surpassed Sowerbyella.
The chilidium of Syndielasma is well developed and forms a narrow arch over
the cardinal process. Thus the posterior characters of Syndielasma, if well pre-
served, should distinguish it from Sowerbyella.

The 2 long, high septa of the brachial interior of Syndielasma are obviously
like those of Sowerbyella. The later members of the latter genus, however, usually
have the front ends of the septa thickened and grown together by shell substance
to produce a steep anterior slope off the front ends of septa. The real distinction
between Syndielasma and Sowerbyella is in the cardinalia, particularly the cardi-
nal process. In Sowerbyella the cardinal process is joined to the chilidial plates
and brachiophores to form a tentlike structure that overhangs the notothyrial
region. In Syndielasma, on the other hand, the cardinal process is a thick boss
with a short shaft occupying the notothyrial cavity. The brachiophores of
Syndielasma in their slender and widely divergent character are not unlike those
of Sowerbyella. Syndielasma thus combines features that are definitely like those
of Sowerbyella with others that remind one strongly of Palaeostrophomena and
its allies.

It is doubtful if Syndielasma is one of the progenitors of Sowerbyella because
it occurs with Sowerbyella bellarugosa. This species occurs at the same horizon
and locality and has the tentlike cardinalia of true Sozwerbyella. It is best to
regard Syndielasma as an early off-shoot from the line that produced Sowerbyella.

SYNDIELASMA BISEPTATUM Cooper, new species
Plate 185, C, figures 14-29

Shell attaining about 4 inch in width, wider than long, semiellipitical in out-
line; hinge forming the greatest shell width; cardinal extremities alate; sides
oblique ; anterior margin broadly rounded; shell thin, valves compressed to form
an unusually narrow body chamber ; costellae narrowly rounded, distant, about 11
in 5 mm. at the front margin. A few oblique wrinkles along the posterior margins.

Pedicle valve gently convex in lateral profile; anterior profile broadly and
slightly convex, the maximum convexity at the middle; beak small, protruding
slightly posterior to the posterior margin; umbo narrowly and slightly swollen

744 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

to produce a low but short fold that may die out near the middle but in some
specimens continues more or less prominently to the front margin ; flanks slightly
convex, long and low.

Brachial valve nearly flat to gently concave; greatest concavity just anterior to
the middle; umbo sulcate, the sulcus continuing and widening anteriorly to form
a prominent but shallow depression that terminates at the anterior margin.
Flanks bounding sulcus flat to gently concave; cardinal extremities flattened.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Fiolotype esics sees ce 8.8 8.5 13.9 15.6 ? 1.0 1.8
Paratype (117565c) ... 9.6 9.0 13.7 ? 1.4 1.9

Types—Holotype: 117565g¢; figured paratypes: 117565a-e,h,i; unfigured
paratypes: 117563a-c, 117505f,j,k.

Horizon and locality—Pogonip group (upper 30 feet) in Nevada: About
t mile above the entrance to Ikes Canyon, Toquima Range, Roberts Mountains
(1°) Quadrangle.

Discussion —No other species of this genus is now known to which Syndie-
lasma biseptatum may be compared. This species occurs with Taphrodonta
parallela which it resembles in superficial characters. Taphrodonta, however, is
a smaller, differently proportioned, and stouter shell than that of Syndielasma so
that the two should not be confused.

Family LEPTELLINIDAE Ulrich and Cooper, 1936

Concavo-convex, costellate Plectamobonitacea with low and expanded cardi-
nal process plate and more or less well developed visceral disk.

Subfamily HEsPEROMENINAE Cooper, new subfamily

Leptellinidae having rudimentary visceral disk.

HESPEROMENA Cooper, new genus

(Greek hespera, west; mene, crescent)

Shell with outline and profiles of Leptellina; strongly geniculated near the
middle ; surface marked by alternating fine and coarse costellae. Pseudopunctate.

Pedicle valve without dental plates and with deep delthyrial cavity; muscle
field large; diductor scars long and slender. Other details not known. Pseudo-
deltidium long, moderately convex.

Brachial valve with short, stout brachiophores ; median septum low ; cardinal
process forming a small suboval shelf overhanging the notothyrial region ; cardi-
nal process with median septal ridge and 2 lateral lobes separated by a narrow
groove. Visceral area marked by a thickened line. Entire surface strongly
pustulose.

Genotype.—Hesperomena leptellinoidea Cooper, new species.

PART «I CHAZYAN AND RELATED BRACHIOPODS—COOPER 745

Discussion.—The interior of this genus is most like that of Leptellina but dif-
fers in not having a strong visceral disk marked by a shelf overhanging the
geniculated portion of the brachial valve interior. It also differs from Leptellina
in the development of the cardinal process. This structure in Leptellina consists
of 2 lateral plates attached to the inner edges of the brachiophores which are
fused to a ridgelike cardinal process; the latter may or may not overhang the
notothyrial region to some extent. In Hesperomena, on the other hand, the
cardinal process is constructed like that of Leptellina, but the fused structure is
oval in outline and overhangs the notothyrial area to a considerable extent.

The structure of the pedicle valve is also different from that of Leptellina.
The latter genus has well-marked dental plates and a short, usually wide, muscle
area. In Hesperomena, on the other hand, dental plates are wanting and the
muscle area is large, with long diductor scars completely unlike those of Leptel-
lina. Hesperomena in its lack of an overhanging visceral disk might be supposed
to be primitive, but the cardinal process appears to be more advanced than in
Lepiellina itself.

HESPEROMENA LEPTELLINOIDEA Cooper, new species
Plate 185, A, figures 1-10

Shell moderately large, wider than long; hinge not equal to the greatest shell
width which is near the middle; sides moderately rounded; anterior margin
strongly rounded ; surface marked by distant rounded costellae.

Pedicle valve unevenly convex in lateral profile, most convex just anterior to
the middle where the valve is abruptly geniculate toward the pedicle valve; an-
terior profile broadly and gently convex; posterior half gently convex; umbo
narrowly swollen, the swelling forming a short and inconspicuous fold. Anterior
half gently swollen and bent toward the pedicle valve to form a long trail with
steep and long anterior slope. Interarea moderately long, apsacline.

Brachial valve most concave just anterior to the middle; posterior half gently
concave; anterior half deflected toward the brachial valve and forming steep
slopes from the cardinal extremities to the anterior: umbo sulcate, the sulcation
forming a shallow and narrow depression which is lost on the brachial trail.
Interarea short, hypercline.

Measurements in mm.—Holotype, length 14.7, brachial length 12.6, midwidth
23.2, hinge width 19.2, thickness 3.4, height 5.9.

Type.—Holotype: 117560.

Horizon and locality—Pogonip group (upper 30 feet) in Nevada: About
1 mile above the entrance to Ikes Canyon, Toquima Range, Roberts Mountains
(1°) Quadrangle.

Discussion.—No other species of this genus is known to which this one may be
compared. The measurements of midwidth and hinge width given above are
based on the half width of the shell.

746 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Subfamily LepTELLInINAE Ulrich and Cooper, 1936

Plectambonitacea having the general appearance of Leptelloidea and with an
elevated visceral disk in the brachial valve. When present, the cardinal process
is a simple ridge with a lateral ridge on each side.

Genus PETRORIA Wilson, 1926
Plate 221, E, figures 29-36
Petroria Witson, Geol. Surv. Canada, Bull. 44, pp. 27-20, pl. 5, figs. 15-18, 1926.

Since its proposal this genus has not been very well known, and some ques-
tion attends its proper age designation. The type specimens were taken from the
Beaverfoot limestone and are associated with an equivocal assemblage. The gas-
tropod Palliseria has proved to be identical with Mitrospira which forms a
prominent zone in the high Pogonip of western United States. Petroria does not
have the structure of the more advanced leptelloids to which it is related but is
more suggestive of the Canadian genus Leptella. In accord with this view is
the presence of Orthis marshalli Wilson and Plectorthis ? sinuatis Wilson which
are Canadian types. Although the writer has not seen specimens of either of
them, the first species suggests Orthambonites and the second reminds one
strongly of Orthidiella. It seems very probable, from the above evidence, that
Canadian and Richmond fossils have been brought together by structural
complications.

Through the kindness of Dr. W. A. Bell of the Canadian Geological Survey
the writer was permitted to etch apart the valves of one of the cotypes of Petroria
rugosa. The specimen selected for this delicate operation was G. S. C. 6754a.
Part of the pedicle valve of this specimen had been broken off, but the brachial
valve was nearly intact. The etching process was carried out successfully, and
the two valves were easily separated.

The pedicle valve has a moderately long interarea slightly overhanging the
delthyrial cavity which is moderately deep. Dental plates are not visible. If
they existed in the young Petroria, they have been obliterated by shell deposit in
the umbonal and delthyrial chambers before the individual reached the size of the
specimen under examination. The muscle area is somewhat triangular and is not
deeply impressed. Each of the vascula media consists of 2 narrow channels sepa-
rated by a broad fold, thus forming a double track extending from the antero-
lateral angle of the muscle area obliquely for half the shell length. The shell is
somewhat thickened at the anterior extremity of the pallial trunk.

In the brachial valve the chilidial plates are prominent and almost close the
notothyrium. The interarea is moderately long. No cardinal process is present,
a feature suggesting Leptella and early origin. The sockets are shallow and
formed by the sloping face of the short brachial processes. The notothyrial cavity
is made obsolete by swelling of shell substance between the brachiophores. The
median ridge extends to the extremity of the visceral disk and is continued from
there to the shell margin. The visceral disk is low, not extended strongly over
the anterior trail. The muscle field is oval and somewhat thickened.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 747

Petroria is very much like Leptella, but a few distinctions between the genera
can be readily seen. The known specimens of Leptella do not show the promi-
nent, wavy lamellae of the exterior of Petroria. Inside the pedicle valve Leptella
is provided with a callosity at the anterior end of the muscle area which is lack-
ing in the Beaverfoot genus. The median septum of Petroria is more prominent
and is extended anterior to the anterior margin of the visceral disk unlike that
of Petroria. Neither genus is provided with a cardinal process. This feature
characterizes many of the early brachiopods and suggests an early Ordovician
rather than late Ordovician age for Petroria. Although the two genera are basi-
cally similar, the differences mentioned are sufficient to distinguish them.

Genus LEPTELLINA Ulrich and Cooper, 1936

Leptellina Utricu and Cooper, Journ. Paleont., vol. 10, No. 7, p. 626, 1936; Geol. Soc. Amer.
Special Pap. 13, p. 190, 1938.

LEPTELLINA ABBREVIATA Cooper, new species
Plate 191, C, figures 23-31

Shell of about average size for the genus, slightly wider than long; greatest
width at the hinge line. Cardinal extremities rounded, nearly a right angle. Lat-
eral margins nearly straight, anterior margin narrowly rounded. Surface multi-
costellate, marked by about 19 thin, highly elevated, strong costellae of which
about 5 reach the beak; spaces between larger costellae occupied by very fine
costellae about 8 in 1 mm. on the brachial valve where they are best preserved.
In addition to the radial ornamentation most of valves covered by fine, closely
spaced concentric lamellae, usually stripped away from some part of the shell.

Pedicle valve strongly convex in lateral profile and with the greatest convexity
at about the middle; posterior third somewhat flattened. Anterior profile still
more convex than the other ; the greatest convexity is at the middle, but the sides
slope steeply to the margins. Umbonal region somewhat flattened; midregion
swollen, and with concave posterlateral slopes to the cardinal extremities. All
slopes including the posterior slope steep. Interarea long, slightly curved,
anacline.

Brachial valve moderately concave with the greatest concavity developed in
the median region. Umbo slightly concave; posterolateral areas flattened ; lat-
eral and anterior portions moderately steeply folded in the direction of the
brachial valve. Interarea nearly as long as the pedicle one; hypercline. Chilidium
small.

Interior: Pedicle muscle field pentagonal with large, widely divergent adjustor
impressions. Diductor impressions elongate tear-shaped, subparallel; adductor
impressions fairly large and located at the base of the callus filling the deep del-
thyrial cavity. Between the anterior ends of the diductors occurs a crater with
steep, coarsely granulose anterior face and moderately deep cavity. Anterior and
lateral portions of valve strongly granulose. Brachial valve with short but wide
visceral disk occupying less than the posterior half.

748 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge Surface
Length length Midwidth width Thickness length Height
HMolotypesy .2 isi. 2 9.8 8.3 II.9 12.4 3.8 13.5 5.0
Paratype (117433g).. 9.7 ? 12.1 13.0 ? 12.0 3.4

Types.—Holotype: 117433a; figured paratype: 117433b; unfigured paratypes:
117433c-h.

Horizon and locality—Oranda formation in Virginia: In the railroad cut
4 mile west of Strasburg, Strasburg (15’) Quadrangle.

Discussion.—This species is characterized by its medium size, strong, distant
costellae, strong convexity, and the large size and considerable width of the
muscle field of the pedicle valve. This species is marked somewhat like L. pul-
chra, but that species is a much larger one. Leptellina abbreviata resembles
smaller specimens of L. tennesseensis but differs markedly in the ornamentation
particularly on the anterior portion of the valve. Leptellina delicatula is approxi-
mately the same size as the Oranda species but is a squarer form with a much
longer pedicle interarea than the Virginia species. Leptellina incompta and
L. abbreviata are approximately the same age, but the Virginia species is much
more convex than the Nevada one although the pedicle interiors are similar.

LEPTELLINA BELLA Cooper, new species
Plate 186, A, figures 1-8; plate 190, A, figures 1-4

Shell small for the genus, wider than long, strongly concavo-convex; hinge
forming widest part; cardinal extremities nearly rectangular, slightly auriculate.
Lateral margins nearly straight ; anterior margin very broadly rounded. Surface
multicostellate, costellae of 3 sizes. In young stages about 7 of the larger cos-
tellae extending from the beak to the margin, but in adults addition of costellae
of intermediate size in the front half increases the number of larger costellae to
about 20 on each side of the median costella. The strongest of the costellae is
the median one which is wider and more elevated than the others. The costellae
of the 2 larger sizes are set in a field of very fine costellae about 15 in 1 mm. This
figure includes 1 large costella. In addition to the radial ornamentation the sur-
face of the posterior part of the valves particularly is marked by minute con-
centric wrinkles.

Pedicle valve moderately to strongly convex in lateral profile with the great-
est convexity in the anterior half while the posterior half is only very gently
convex; anterior profile highly arched. Beak protruding slightly posterior to
the posterior margin; umbo swollen and elevated slightly. Lateral and anterior
slopes very steep. Median region somewhat more swollen than the surrounding
areas to form an ill-defined fold. Interarea moderately long, apsacline.

Brachial valve deeply concave with the greatest concavity in the median por-
tion ; region near cardinal extremities less concave. Umbonal region only gently
concave. Interarea hypercline. Chilidium small.

Interior: Muscle area of the pedicle valve deeply impressed, very small, hav-
ing a length equal to about one-sixth that of the valve. Vascula media or main

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 749

pallial trunks slender, divergent, not deeply impressed and extending to about
the middle. Brachiophores short, slender; median ridge slender, well elevated ;
visceral disk wide, occupying the posterior two-thirds to three-fifths of the valve.
Muscle marks not deeply impressed.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness

PRIEST eer ce icin trie dx ws aaiecete es cna e 7.4 6.4 8.9 8.9 2.5
Paratype Cri7agsa) eer cc. ec ereieeet 6.0 ? 72 8.9 ?
Wy GUTGA SRD acs eo lester a ous 6.3 P 8.3 9.6 ie
ae (brachial valve 117435d).... ? 5.3 8.2 85 ?

Types.—Holotype: 117434c; figured paratypes: 117434b, 117435b,c,f; un-
figured paratypes: 117434a, 117435a,d,e,g-1.

Horizon and locality— Whitesburg formation in Tennessee: 15 miles west of
Bulls Gap, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Chatham Hill formation in Virginia: Grayson Farm, 4 miles southwest of
Bland, Bland County.

Discussion.—This is a small and beautifully marked species characterized by
the fairly close crowding of the major costellae on the anterior slope and the
prominence of the median costella. This species is unlike any other described
in its ornamentation. It is suggestive of L. tennesseensis in ornamentation, but
that species attains twice the size of L. bella.

LEPTELLINA DELICATULA (Butts)
Plate 188, C, figures 13, 14; plate 191, D, figures 32-39
Plectambomites delicatula Butts, Alabama Geol. Surv., Special Rep. 14, p. 116, pl. 26, figs. 20,

21, 1926.
Plectambonites cf. P. pisum Butts, idem, p. 116, pl. 26, figs. 18, 19, 36, 37, 1926.

Shell of about medium size for the genus, subquadrate in adult outline, a little
wider than long; cardinal extremities acute to obtuse depending on age and
preservation. Lateral margins rounded, oblique to nearly straight. Front mar-
gin narrowly rounded. Surface marked by costellae of 3 sizes. In young speci-
mens 5 large costellae stand out over a field of very fine costellae. In adults
many costellae of intermediate size are intercalated on the anterior slope and
number about 40. These are separated by the finest costellae about 7 in a milli-
meter measured at the front of the brachial valve of an adult.

Pedicle valve strongly convex in lateral profile with the greatest convexity
located at about the middle; anterior profile a strongly convex bow equal in
height to about half the width of the shell. Umbo and beak inconspicuous ; middle
and anterior portions strongly swollen; lateral slopes descending steeply to the
lateral and cardinal extremities. Interarea long, orthocline, slightly curved.
Pseudodeltidium short, strongly arched.

Brachial valve deeply concave with the greatest concavity at about the center ;
lateral and anterior portions strongly elevated to form a deep cup. Valve shallow
at cardinal extremities which are somewhat flattened. Lateral margins sloping

750 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

rapidly to cardinal extremities. Umbonal region only slightly concave; region on
each side of umbo and along posterior margin flattened. Interarea short, about
half the length of the pedicle interarea ; hypercline.

Interior: Pedicle valve having dental plates strong with deep umbonal cavi-
ties, sloping inward; teeth small; delthyrial chamber deep. Muscle field thick-
ened, short as usual in the genus. Ridge in front of muscle field extending to
about middle. Brachial valve with long, slender brachial processes extending
strongly anterolaterally. Other visible features as usual in the genus.

Measurements in mm.—

Brachial Surface Mid- Hinge Thick-
Length length length width width ness Height

Eolotyge v.20 RA, 6.9 5.8 9.0 8.5 9.7 1.9 3.3
Hypotype (71499a)... 7.8 6.4 9.5 8.7 8.9 2.1 37
“~ (117436d).. 10.2 7.5 13.5 10.8 110+ 2.9 5.0
« (117436a).. 8.4 6.9 11.5 8.8 10.7 2.4 4.6

Types——Holotype: 71500; figured hypotypes: 117436a,d,e; unfigured hypo-
types: 71499a, 117436b,c.

Horizon and locality.—Little Oak formation in Alabama: 4 mile north-north-
east of Pelham, Bessemer Iron District (15’) Quadrangle; west side U. S. High-
way 31, SWiSW43 sec. 13, T. 20 S., R. 3 W., 4 mile N. 10° E. of Pelham Sta-
tion, 2 miles north of Pelham, Bessemer Iron District (15’) Quadrangle; inter-
section of Bailey Gap road with main road, SW4SW43 sec. 13, T. 19 S., R 2 W.,
13 miles northeast of Newhope Church, Vandiver (15’) Quadrangle.

Discussion—This species is somewhat variable and has an interesting growth
development. The young are transverse and have acute cardinal extremities. The
adult form has an unusually long interarea on the pedicle valve, and the outline
becomes strongly rectangular with the length slightly less than the width. The
long interarea on the pedicle valve, the deep brachial valve and rectangular form
distinguish L. delicatula from all the other species herein described. This species
never attains the large size of L. tennesseensis which is its closest relative in time
and appearance.

LEPTELLINA INCOMPTA Cooper, new species
Plate 191, B, figures 9-22

Shell of about medium size for the genus, wider than long with the hinge equal
to or forming the greatest width; sides moderately oblique, gently rounded; an-
terior broadly rounded ; costellae not visible on perfect specimens because of the
crowded, thin lamellae which give the shell a rough or untrimmed appearance ;
costellae of 2 sizes, the larger ones about I mm. apart at the front margin of an
adult, remainder of shell covered by a mat of fine costellae.

Pedicle valve evenly and moderately convex in lateral profile; anterior profile
moderately domed, with the median region somewhat narrowly convex and with
long, steep lateral slopes. Beak small and narrowly protruding slightly posterior
to the posterior margin; umbo moderately convex; median region moderately
swollen; posterior slope shorter and somewhat steeper than the anterior slope.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 751

Interarea long, gently apsacline. Interior with deep delthyrial cavity having
thickened walls ; dental plates obscured by adventitious shell. Muscle field large,
with elongated diductor scars occupying the posterior third ; vascula media short,
separated by a narrow granular area.

Brachial valve moderately deep, the depth increasing with age; maximum con-
cavity just anterior to the middle; umbo and surrounding area gently concave;
cardinal extremities flattened. Interarea short, hypercline. Interior with low
visceral disk having a highly elevated median septum.

Measurements in mm.— Brachial Surface Mid- Hinge —Thick-

Length length length width width ness Height
FIOMOGy PE sphaceet «9. - 3 10.4 8.8 13.5 14.2 TAANE uth 2:6 4.8
Paratype (117438a)... 9.1 PEE 115 T2204. EADS ue 3.8
: (117438b)... 80 6.9 10.5 10.0 Ter 22 3.4

Types.—Holotype: 117438c; figured paratypes: 117438a,b,d,e.

Horizon and locality—Dark shale below Eureka quartzite in Nevada: On
the north-facing nose of hill 8167, Martins Ridge, Monitor Range, Roberts
Mountains (1°) Quadrangle.

Discussion.—Specimens of this species have a ragged appearance because of
partial peeling of the fine lamellae. Transverse form, low convexity and a large
pedicle muscle area characterize this species. Leptellina abbreviata is thought
to be of about the same age, but L. incompta is a much less convex form. Leptel-
lina sublamellosa is also characterized by prominent development of the lamellae,
but the species is somewhat smaller, more transverse, and proportionately more
convex.

LEPTELLINA OCCIDENTALIS Ulrich and Cooper

Plate 180, C, figures 30-37

Leptellina occidentalis Utricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 191, pl. 39B,
figs. 3, 7, 1938.

Additional material of this species collected after the appearance of Special
Paper 13 has yielded specimens quite suitable for illustration of many of the
characters mentioned in the original description. Not seen in the original ma-
terial are the fine lamellae which cover most of the surface, like those of other
well-preserved specimens of Leptellina from higher formations. This species is
readily distinguished from all other known species of the genus by its small size,
gently convex to nearly flat brachial valve, and the low and short visceral disk.

Types.—Holotype: 92869a; paratypes: 92868a, g286gb-d, 92870a,b; figured
hypotypes: 108133a-e, 117440a-c.

Horizon and locality—Common in the topmost beds of the Pogonip group in
Nevada: In Ikes Canyon, on the east side of the Toquima Range, Roberts
Mountains (1°) Quadrangle.

LEPTELLINA PLATYS Cooper, new species
Plate 186, D, figures 13, 14

Shell of about medium size for the genus, of low convexity, wider than long
and with the hinge about equal to the maximum width. Sides slightly oblique,

752 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

gently rounded; anterior margin broadly rounded. Costellae of several sizes,
about 2 of the larger ones in a millimeter at the front margin.

Pedicle valve with lateral profile gently convex and with the maximum con-
vexity slightly anterior to the middle; anterior profile broadly and moderately
convex and with long, gentle lateral slopes ; umbo gently convex; median region
gently swollen ; interarea long, apsacline.

Brachial valve gently concave and with the maximum concavity at about the
middle; umbo concave; posterior slope descending moderately toward the mid-
dle; cardinal extremities somewhat flatly concave; interarea short, hypercline.

Measurements in mm.—Holotype, length 10.0, brachial length 8.8, surface
length 11.5, midwidth 14.2, hinge width 15.6, thickness 2.3, height 3.4.

Type.—Holotype: 117439.

Horizon and locality—Benbolt formation in Virginia: + mile east of Speers
Ferry, Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—This species is characterized by its low convexity and is there-
fore directly comparable to only two other species: L. occidentals and L. pri-
maria. From the former L. platys differs in size and ornamentation; from the
latter it differs in being somewhat more convex and having stronger ornamen-
tation.

LEPTELLINA PRIMARIA Cooper, new species

Plate 187, A, figures 1-7

Shell large for the genus, concavo-convex but not strongly convex; cardinal
extremities rectangular to acute; lateral margins sloping inward; anterior mar-
gin broadly rounded. Surface marked by narrowly rounded, distant costellae,
about 5 in the space of I mm. at the front of a valve about 7 mm. long. In ad-
dition to costellae most of the anterior three-quarters is covered by fine con-
centric lamellae.

Brachial valve moderately concave and agreeing well with the convexity of
the pedicle valve; umbo concave, extended forward as a narrow but moderately
deep sulcus for at least half the length of the valve, not well defined in the an-
terior portion. Posterolateral areas bounding posterior part of sulcus flattened ;
lateral areas gently concave. Interarea short, hypercline.

Interior: Interior of pedicle valve unknown. Brachial interior with a low
visceral disk occupying slightly more than the posterior half; median ridge low
and wide. Cardinalia with short, thick, divergent brachial processes. Cardinal
process simple, intimately grown to the chilidial plates, the anchylosed struc-
tures forming a narrow plate. Musculature not preserved.

Measurements in mm.—

Brachial Surface Mid- Hinge Thick-
Length length length width width ness Height

Eoloty pel isi See ee 10.7 9.4 12.0 14.8 16:06:27) io 3.5
Paratype (117441b)... 69 ? 7.0 8.9 10.9 5 ?

Types.—Holotype: 117441d; figured paratypes: 117441a-c.
Horizon and locality —Crown Point formation in New York: Valcour Island,
Lake Champlain, Plattsburg (15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 753

Same horizon in Vermont: Just north of neck of Providence Island, Lake
Champlain, Plattsburg (15’) Quadrangle.

Discussion.—This species is a fairly early member of the genus as it occurs
in the Crown Point formation of the Chazy group. It is flatly convex, is lamel-
lose like most other species and has fairly fine ornamentation. It is also charac-
terized by a large visceral area which does not strongly overhang the geniculated
trail. This species differs from all others herein described, except L. platys and
L. occidentalis, in its low convexity. It is a larger and deeper shell than L. occi-
dentalis but is somewhat less convex and larger than L. platys and is differently
ornamented.

LEPTELLINA PULCHRA Cooper, new species
Plate 189, A, figures 1-23; plate 195, C, figures 9-16; plate 219, G, figure 14

Shell large for the genus, strongly concavo-convex, wider than long. Cardinal
extremities obtuse, auriculate. Lateral margins well rounded; anterior margin
broadly rounded. Surface marked by 8 to Io narrow, elevated threadlike cos-
tellae that stand out over a field of very fine costellae, about 5 in 1 mm. The
fine costellae are of very even grade. In addition to the costellae, 2 specimens
show evidence of fine concentric lamellae like those of Sowerbyites. In some
specimens a few oblique wrinkles are present along the posterior margin on each
side of the beak.

Pedicle valve with posterior third somewhat flattened but strongly convex in
the anterior two-thirds in lateral profile; anterior profile a narrowly rounded
arch. Beak small, protruding slightly beyond the posterior margin. Umbonal
region slightly swollen; swelling continued forward in the median part of the
valve to the front margin to form a fold. Lateral slopes slightly convex, steep.
Anterior slope steep. Interarea slightly apsacline.

Brachial valve deeply concave with the greatest concavity just anterior to the
middle; umbo concave, the concavity continued anteriorly as a poorly defined
sulcus ; flanks gently concave and regions parallel to posterior margin also con-
cave. Cardinal extremities concave.

Interior: Muscle area of pedicle valve wide and short, equal in length to about
one-quarter the length of the valve; dental plates short and stout; adjustor-
diductor patches set off from the adductor field by low ridges in old shells;
pallial sinuses not strongly impressed. Brachial valve with well-developed, large
visceral area, the front margins of which are produced forward and overhang
the geniculated front slope; median ridge slender, high, not extending to the
chamber under the cardinal process. Brachial processes slender and flat. Cardi-
nal process a slender ridge bounded by 2 triangular depressions, the whole
grown together with the chilidial plates to form a single plate, which in this
species, is undercut and overhangs an umbonal chamber somewhat like the cardi-
nalia of Sowerbyella. Area of muscle attachment thickened and marked by
oblique ridges.

754 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Surface Mid- Hinge Thick-
Length length length width width ness Height

Elolotypertieis. okt. Je 12.8 Tra 14.5 17.4 TOOul) | 22 5.5
Paratype (117444m) . 13.5 ip 18.0 17.0 18.9 ? 7:3
s (117443)... 12.7 12.2 17.5 17.9 16.5 ey 5.9
ee (117444e).. 14.7 i 19.0 17.2 18.0 ? ? 8.0

Types.—Holotype: 117444d; figured paratypes : 117442a-e, 117443, 117444a-c,
e-h, 123284; unfigured paratypes: 117444i-m.

Horizon and locality.—Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle ;
McNutt Quarry, 12 miles southwest of Bland, Burkes Garden (15’) Quadrangle.

Edinburg formation (lower Liberty Hall facies) in Virginia: 1.8 miles S.
4° W. of Bethel Church, 5.9 miles due east of Harrisonburg, Harrisonburg (15’)
Quadrangle.

Botetourt formation in Virginia: 1 mile northwest of Lexington, Lexington
(15’) Quadrangle.

Benbolt formation in Virginia: 4 mile southeast of Richpatch, Eagle Rock
(15’) Quadrangle.

Pratt Ferry formation in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton
(15’) Quadrangle.

Discussion.—This species is one of the largest and most beautiful of this genus.
It is characterized exteriorly by having strong and distant costellae in a mat of
fine costellae. The distant nature of the larger costellae is maintained on the
geniculated trail as well as on the posterior part. In this respect it differs from
L. tennesseensis, its nearest relative, in which the trail is marked by fairly
crowded major costellae.

LEPTELLINA SUBCARINATA Cooper, new species
Plate 190, E, figures 32-39

Shell wider than long with rectangular or obtuse cardinal extremities; lateral
margins gently rounded; anterior margin broadly rounded to somewhat nasute.
Surface multicostellate, costellae of 3 sizes, many of the ones of intermediate size
intercalated at the place of geniculation and occupying the front slope which is
thus marked by many of the larger costellae. About 60 of the strong and inter-
mediate costellae may be counted at the front margin of an average-size shell.

Pedicle valve moderately convex with the greatest convexity in the midregion.
Anterior profile only moderately convex with moderately steep sides sloping
away from a low, rounded median elevation. Fold low, narrow, extending to
the front margin. Interarea moderately long with a narrow delthyrium and nar-
rowly arched pseudodeltidium.

Brachial valve having a moderate concavity, deepest in the posterior part of
the median region. Concavity extending forward nearly to the front margin
in correspondence with the fold of the pedicle valve. Lateral regions bounding

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 755

the sulcus gently convex to flattened depending on the age. Interarea short,
hypercline.

Interior: Muscle area of pedicle valve small, deeply impressed, equal to about
one-fourth the width and one-fifth the length. Dental plates short, umbonal cavi-
ties well filled by callus in the adult. Vascula media of the pallial system short,
not deeply impressed. Ridge anterior to muscle field fairly high, thin and well
anterior of the muscle field. Brachial valve with only moderately large visceral
area which extends anteriorly to about the middle of the valve, and is produced
forward as an overhanging ledge for a short distance. Median ridge broad and
low. Muscle marks not well impressed.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
PANG ENES EO ae 8 8 sities ares s-chpasiare, om 8.0 ? 9.9 13.8 ?
Paratype (pedicle valve 117446f) ... 10.3 ? 13.4 14.1 ?
af (brachial valve 117446b).. ? 78 12.3 12.8 ?

Types.—Holotype: 117446a; figured paratypes: 117446b,c,f-h; unfigured
paratypes: 117446d,e,i-k.

Horizon and locality—Base of Athens formation in Tennessee: 24 miles
south-southeast of Riceville, Calhoun (T.V.A. 125-SW) Quadrangle; 2 miles
south of Philadelphia, Philadelphia (T.V.A. 131-NW) Quadrangle; 600 feet
S. 40° E. of the railroad crossing 1 mile northeast of the courthouse in Athens,
Athens (T.V.A. 125-SE) Quadrangle; 0.2 mile southeast of Britton Church,
24 miles northeast of Calhoun, Calhoun (T.V.A. 125-SW) Quadrangle.

Discussion.—This species is known only from the base of the Athens shale
in the belt running through Athens, Tenn. The species has moderate convexity,
a somewhat keeled pedicle valve, small muscle field in the pedicle valve, and the
visceral disk not strongly overhanging the trail. The species is nearest L. tennes-
seensis but never attains the large size of that species nor its great convexity.

LEPTELLINA SUBLAMELLOSA Cooper, new species
Plate 188, B, figure 12; plate 188, D, figures 15-24; plate 190, B, figures 5-8;
plate 190, C, figures 9-25

Small, wider than long and with the hinge forming the widest part; cardinal
extremities acute ; sides oblique, gently rounded ; anterior margin broadly to nar-
rowly rounded; surface finely costellate, costellae of unequal size; part or most
of surface covered by closely spaced wavy lamellae.

Pedicle valve with strongly convex lateral profile, the maximum convexity
located at or near the middle; anterior and lateral slopes nearly equal in length
and nearly equal in steepness; anterior profile ranging from moderately to
strongly convex in the median region and with long, steep lateral slopes. Beak
small; umbo and median regions swollen. Interarea moderately long, orthocline.
Interior with short but deeply impressed muscle scars; vascula media incon-
spicuous.

Brachial valve fairly strongly concave particularly in the median region and

750 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

just anterior to it; umbo concave; area just anterior to posterior margin form-
ing a more or less deep groove extending to the cardinal extremities. Interarea
moderately long, hypercline. Interior with strong, erect cardinal process, strong
median ridge, and elevated visceral disk with margins overhanging geniculated
area; pallial marks impressed on geniculated area.

Measurements in mm.—

Brachial Surface Mid- Hinge Thick-
Length length length width width ness Height

FLOMGEV IIE voles ce pues g 8s 66 8.1 6.6 10.5 9.9 10.8 2.6 3.9
Paratype (117447a)..... 78 6.4 10.5 9.6 10.7 27 3.9
fe (117447b)..... 8.2 6.9 11.0 10.0 10.6 2.5 ag

Types.—Holotype: 117447¢ ; figured paratypes: 117447b,e,f,h, 117449a,¢c,d,f,g,
117450a, 117451a; unfigured paratypes: 117447a,c,d,i, 117448, 117449b,e,
117450b, 117451b,c.

Horizon and locality—Chatham Hill formation in Virginia: 1.2 miles S. 31°
E. of Sharon Springs, Burkes Garden (15’) Quadrangle; Grayson Farm, 4 miles
southwest of Bland, Bland County.

Benbolt formation (base) in Virginia: West side of hill east of Cedar Point
School, Hilton (T.V.A. 197-NE) Quadrangle; 0.2 mile south of middle fork
of Moccasin Creek, 14 miles due south of Hansonville, Hansonville (T.V.A.
205-SW) Quadrangle.

Edinburg formation (Cyrtonotella zone) in Virginia: Ravine on south side
railroad tracks, mile east of Strasburg Junction, Strasburg (15’) Quadrangle;
(?) 14 miles north of Double Toll Gate, Winchester (15’) Quadrangle.

Discussion.—This species is characterized by its ragged exterior produced by
patches of lamellae of considerable size adhering to the shell. The species is of
moderate size and fairly transverse. It is not so large nor so convex as L. ab-
breviata but is more convex than L. incompta which it resembles in its ragged
exterior. Leptellina sublamellosa is like some of the younger forms of L. deli-
catula but does not attain the rectangular outline nor does it develop the long
interarea as on the pedicle valve of the Alabama species.

LEPTELLINA TENNESSEENSIS Ulrich and Cooper
Plate 187, C, figures 9-13; plate 187, D, figures 14-30; plate 188, A, figures I-11;
plate 189, B, figures 24-29; plate 190, D, figures 26-31
Leptellina tennesseensis ULRicH and Cooper, Journ. Paleont., vol. 10, No. 7, p. 626, 1936;
Geol. Soc. Amer. Special Pap. 13, p. 192, pl. 39A, figs. 1, 2, 4, 5, 1938.

Plectambonites delicatulus RAyMoND (not Butts), Bull. Mus. Comp. Zool., Harvard Coll.,
vol. 68, No. 6, p. 207, pl. 3, fig. 11, 1928.

Shell large, variable, varying from wider than long to having the length and
width about equal. Cardinal extremities acute and generally auriculate. Lateral
margins nearly straight or oblique and generally rounded in old specimens.
Front margin broadly to narrowly rounded, occasionally somewhat nasute. Sur-
face multicostellate ; young valves marked by 5 narrow but strong primary cos-
tellae that extend to the beak. As the shell grows, costellae of a size intermediate

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 757

between these and the fine costellae covering most of the surface are intercalated
and become most numerous on the anterior and anterolateral slopes. Eleven or
twelve of these costellae occupy a space of 5 mm. at the front margin. As many
as 4 of the finest costellae occupy the space between the intermediate costellae.

Pedicle valve moderately convex in lateral profile with the greatest convexity
at about the middle in young specimens but in the posterior half in old speci-
mens. Front profile variable depending on the age; most strongly convex in the
older individuals. Beak inconspicuous; umbo small, slightly swollen, extended
forward as an ill-defined fold on the flattish posterior portion, but generally not
continued far forward, although some specimens show evidence of an indistinct
fold at the front margin. Posterolateral slopes gently concave. Anterolateral
slopes generally steep in shells of all ages; front slope steep to moderately steep
depending on age, the older shells having a longer and more gentle anterior slope.
Interarea only slightly curved, apsacline to orthocline. Pseudodeltidium mod-
erately long, narrowly arched.

Brachial valve following the curvature of the pedicle valve fairly closely, most
deeply concave at the middle or slightly posterior to the middle. Umbo gently
concave with the concavity produced anteriorly to about the middle. Postero-
lateral regions flattened. Cardinal extremities sulcate. Interarea short, hy-
percline.

Interior of pedicle valve with small teeth, dental plates strongly convergent,
thick ; umbonal cavities well filled by callus. Delthyrial cavity moderately deep ;
muscle marks well impressed on a thickened delthyrial floor. Diductor-adjus-
tor scars small, often separated by a low ridge at the posterior of which is located
the small oval adductor field. Vascula media often much thickened, short, having
the first bifurcation at about the middle of the valve.

Brachial valve with a visceral disk occupying about two-thirds the width and
more than half the length. Median ridge strongly elevated at the front, lost in
the callus under the cardinalia. Cardinal process and chilidial plates forming a
flat piece supported anteriorly by a thickening of callus. Brachial processes long,
flat plates. Adductor scars not discernible.

Measurements in mm.—

Brachial Surface Mid- Hinge Thick-
Length length length width width ness Height

BAI Gt Ce bess. she steteberots 10.5 8.2 13.5 10.4 12.0 3.2 4.4
Hypotype (108135s).. 10.4 8.3 12.5 12.3 TOG. 1316 5.6
se (108135h).. 11.4 9.0 16.0 12.5 re q2 5.8

as (108139)... 11.8 10.3 15.5 14.8 14.6 2.6 5.4

Types.—Holotype: 92871 ; figured hypotypes: 108135d,e,g,h,m,o,p,s-u, 117452,
117453a,b, 117454a,b, 117455a,b, 117456a, measured hypotype: 108139.

Horizon and locality.—Arline formation in Tennessee: On both sides of an
old road in glade, 4 mile southeast of Friendsville, Concord (T.V.A. 138-SW)
Quadrangle ; 3 and 6 miles southeast of Knoxville; McMullens, Meadow (T.V.A.
139-NW) Quadrangle; 1,500 feet south of the mouth of Burnett Creek, Shooks
Gap (T.V.A. 147-NE) Quadrangle; 6 to 10 miles southeast of Loudon, Loudon

758 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

(30') Quadrangle; 2 miles south of Philadelphia, Philadelphia (T.V.A.
131-NW) Quadrangle; quarry 4 mile northeast of St. Clair, Bulls Gap (T.V.A.
171-SE) Quadrangle; 100 yards southwest of the Negro Cemetery, 4 mile north-
east of Friendsville, Concord (T.V.A. 138-SW) Quadrangle; 10 feet below
Holston= Red Knobs formation, 1 mile east-northeast of Friendsville, Louisville
(T.V.A. 138-SE) Quadrangle.

Arline formation in Virginia: Quarry at Marion, Marion (T.V.A. 218-SE)
Quadrangle.

Fetzer tongue in Tennessee: On the south side of the road 200 yards south-
west of Blockhouse, Blockhouse (T.V.A. 148-NW) Quadrangle.

Tellico formation in Tennessee: On the Chapman Highway (Tennessee
Highway 71) 1.3 miles east-northeast of Cusick, Walden Creek (T.V.A.
156-SW) Quadrangle.

Little Oak formation in Alabama: Lock 3, cut on Seaboard Airline RR. 6
miles east-northeast of Ragland, St. Clair County.

Botetourt formation in Virginia: On Virginia Highway 114, 2.3 miles west
of the Montgomery-Roanoke County line, 12 miles northeast of Blacksburg.

Discussion.—This species as here described is a somewhat variable form con-
sisting of individuals having the length and width nearly equal while others are
definitely somewhat transverse. The exterior is characterized by strong con-
vexity and a strongly geniculated trail marked by somewhat crowded strong
costellae between which occur finer ones. The anterior is often somewhat nasute
when viewed from the side showing the brachial valve. Young forms are trans-
verse. Inside the pedicle valve the muscle area is small for such a large shell and
contrasts strongly with L. abbreviata which is smaller but with a huge muscle
area.

Leptellina tennesseensis is a large species and is thus comparable to L. pulchra;
it differs from that species in its less transverse outline and in the possession of
crowded larger costellae on the geniculated trail.

LEPTELLINA TRANSVERSA Cooper, new species
Plate 191, A, figures 1-8

Shell of about usual size for the genus, unusually transversely subelliptical
in outline. Hinge forming widest part. Lateral and anterior margins forming
a single broad curve. Surface costellate, 3 to 5 of the larger costellae in a space
of 2 mm. at the anterior margin.

Pedicle valve strongly convex in lateral profile with the maximum curvature
near the middle. Anterior profile a broad arch slightly elevated medially. Umbo
narrowly convex; beak small, protruding very slightly posterior to the posterior
margin which is nearly straight. Umbonal ridge continued anteriorly as a low
and narrow fold for about three-fourths the valve length but less distinctly in
the anterior quarter. Flanks broad, slightly concave or nearly flat and with long,
gentle slopes. Anterior slopes very steep. Interarea moderately long, apsacline.

Brachial valve deeply concave in lateral profile, the concavity closely follow-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 759

ing that of the pedicle valve. Umbo sulcate, the sulcus being continued anterior
to the front margin as a narrow, shallow depression. Flanks bounding sulcus
broadly and gently concave transversely but narrowly and deeply concave longi-
tudinally. Interarea short, hypercline ; cardinal process and chilidial plates small,
fused into a single plate.

Interior of pedicle valve with widely flaring dental plates. Interior of brachial
valve with median septum reaching the point of maximum curvature and mod-
erately elevated anteriorly but very low posteriorly. Edge of visceral area low
and inconspicuous.

Measurements in mm.—Holotype, length 9.2, brachial length 7.6, surface
length 12.5, midwidth 20.9+, hinge width ?, thickness 2.8, height 4.5.

Types.—Holotype: 117457a; figured paratype: 117457c; unfigured paratypes:
117457b,d.

Horizon and locality—Arline formation (near top) in Virginia: Near en-
trance to Porterfield Quarry, 5 miles east of Saltville, Maccrady (T.V.A.
218-NW) Quadrangle.

Discussion——This species has some of the features of L. tennesseensis, to
which it is probably related, but differs therefrom by its unusually transverse
outline. It differs from all other species of Leptellina herein described by the
same character.

LEPTELLINA sp. 1
Plate 187, B, figure 8

A new species represented by a single brachial interior is the largest Leptel-
lina yet found. Its length is 16.3 mm., midwidth 26.1 mm., hinge width 27.4 mm.
plus. The brachiophores are short ; the cardinal process fused with chilidial plates
is large and overhangs the interior; the median septum originates 24 mm. an-
terior to the cardinal process and is narrow and elevated at the front. It termi-
nates at the anterior end of the visceral disk which is 11 mm. long and moder-
ately overhangs the anterior geniculated part of the valve. Muscle scars cannot
be differentiated.

Figured specimen.—117459.

Horizon and locahity.—Edinburg formation (Cyrtonotella zone) in Virginia:
In the ravine opposite the switch just east of Strasburg Junction, Strasburg
(15’) Quadrangle.

BILOBIA Cooper, new genus
(Latin bi, two; lobus, lobe)

Shells small, concavo-convex, with the pedicle valve tumid; cardinal extremi-
ties auriculate ; anterior commissure sulcate ; surface multicostellate ; a few strong
costellae standing out in a field of very fine costellae.

Pedicle valve with deeply impressed large muscle field ; diductor scars elongate,
divergent ; adductor field oval in outline, deeply impressed, separating the pos-
terior ends of the diductors. Teeth thick; dental plates stout ; umbonal cavities
filled by callus; dental plates extended as stout ridges around outside margin

760 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

of muscle field. Vascula media short and thick, bifurcating into a larger inner
branch and a small, shorter outer branch. Interarea curved, longer than the one
on the brachial valve, hypercline. Pseudodeltidium short.

Brachial interior with strongly bilobed visceral disk, lobes triangular to
rounded and the seat of attachment of the adductor muscles. Lobes with ele-
vated rims on inside ; rims extending nearly to cardinal process. Lobes separated
by a high, thin median septum extending to about the middle. Brachial processes
short and small; cardinal process with short, stout shaft bearing 3 ridges on the
myophore face, a median elevated ridge and lateral lower ridges.

Genotype.—Bilobia hemisphaerica Cooper, new species.

Discussion—Bilobia can be recognized by its nearly hemispherical brachial
valve and the bilobed character of the visceral disk. The genus is most like
Leptellina in all its characters but differs in its greater sphericity, generally larger
pedicle muscle field, and in the bilobed character of the visceral disk. The latter
is brought about by lack of development of a prominent median septum.

In the European faunas Bilobia occurs in the Kuckers formation of Estonia
where it is represented by B. musca (Opik). It occurs in the Girvan fattna of
Scotland where it is known as Bilobia etheridgei (Davidson). In the Appa-
lachians this genus has been taken from the lower part of the Edinburg (Cyrto-
notella zone) Shippensburg, and Oranda formations. It is also known in the
Rysedorf conglomerate. It extends from the Oranda into the base of the Mar-
tinsburg shale in Virginia where it occurs with elements of the Salona fauna.

BILOBIA HEMISPHAERICA Cooper, new species
Plate 192, C, figures 16-20; plate 193, C, figures 10-15; plate 193, D, figures 16-36;
plate 194, F, figures 31-36
Plectambonites pisum BASSLER (not Ruedemann), Cambrian and Ordovician: Maryland
Geol. Surv., p. 253, 1919.

Shell small, almost hemispherical in lateral profile; wider than long with the
greatest width at the hinge; cardinal extremities auriculate. Lateral and anterior
margins irregular; front margin varying from broadly rounded to nasute. Pos-
terior swollen part of pedicle valve marked by 3 strong costellae that stand out
over all the others. At the front margin about 17 strong costellae occur in a
matrix of fine lines, 8 or 9 of the latter in a space of 1 mm. The costellae of the
brachial valve seem to have fewer of the large costellae, but this may be because
of faulty preservation. Many of the specimens in the anterior parts of both valves
are marked by concentric lamellae like those of the associated Bimuria lamellosa.

Pedicle valve nearly hemispherical in lateral profile and narrowly convex in
anterior profile. Umbo and median part of valve swollen; all slopes steep but
more particularly the lateral ones which may be as steep or steeper than the an-
terior slope. Posterolateral area leading to the cardinal extremities narrowly
rounded. Interarea short, curved, acutely hypercline in position. Pseudodel-
tidium short in the middle part, extended laterally as an elevated rim on the
sides of the delthyrium.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 761

Brachial valve deeply concave with the greatest concavity at about the middle.
Posterolateral areas concave; umbo concave; lateral and anterior portions
strongly folded toward the brachial valve to form a deep cup of the valve. Chi-
lidium large; interarea short and hypercline.

Interior: Pedicle interior with deeply sunk muscle field, diductor scars long,
straight, and divergent; pallial and genital marks strongly impressed. Brachial
valve with moderately elevated adductor lobes, moderately strong median septum.

Measurements in mm.—

Brachial Surface Mid- Hinge Thick-
Length length length width width ness Height

HolotypeCu tee 9.0 6.1 15.0 10.5 11.7 2.9 5.8
Paratype (11I1099a).... 9.3 7.0 15.0 9.0 10.0 3.0 6.0
‘4 Crt7401a) «005 77 6.6 11.0 9.2 9.7 3.3 4.1

Types——Holotype: 111099b; figured paratypes: 111087a-c, 111099a,c-f,
117460a,b, 117461a,b, 117462; unfigured paratypes: 111087d, 111099g-k,
117461c.

Horizon and locality—Oranda formation in Virginia: 4 mile west of Stras-
burg; just west of junction of Virginia Highways 617=910, and 777, about
0.2 mile north of Green Mount Church, Broadway (15’) Quadrangle; Bowman
Farm, 0.3 mile east of U. S. Highway 11, 1 mile southwest of Woodstock, Edin-
burg (15’) Quadrangle; on Virginia Highway 55, 0.4 mile west of U. S. High-
way 11, north edge of Strasburg, Strasburg (15’) Quadrangle; on U. S. High-
way II, 4 mile south-southwest of Tumbling Run, southwest of Strasburg,
Strasburg (15’) Quadrangle; 200 yards southeast on Virginia Highway 616,
3-5 miles southwest of Mount Jackson, Mount Jackson (15’) Quadrangle; dam
on Shenandoah River, 15 miles N. 61° E. of Edinburg, Edinburg (15’) Quad-
rangle.

Same formation in Pennslyvania: 1 mile northwest of Guilford Springs,
25 miles southwest of Chambersburg, Chambersburg (15’) Quadrangle; 1 mile
south of St. Thomas, Mercersburg (15’) Quadrangle.

Rodman formation in Pennsylvania: At Bellefonte, Bellefonte (15’) Quad-
rangle.

Dark shale below Eureka quartzite in Nevada: On the north slope of hill
8167 on Martins Ridge, Monitor Range, Roberts Mountains (1°) Quadrangle.

Martinsburg formation (part with Brongniartella=Salona) in Virginia: On
Virginia County Road 617=910, 0.15 mile north of Green Mount Church,
Broadway (15’) Quadrangle.

Discussion.—This species is characterized by its large size and strongly in-
flated pedicle valve, thus differing markedly from B. virginiensis. The Oranda
species seems to be less swollen than B. pisum and is usually wider along the
hinge than that species.

BILOBIA MUSCA (6pik)

Plate 192, D, figures 21-24

Specimens of this species are introduced for comparison with the Appalachian
species.

762 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Hypotypes: 84258a-c.
Horizon and locality——Kuckers formation (3ca): At Kohtla in Estonia.

BILOBIA PISUM (Ruedemann)

Plectambonites pisum RUEDEMANN, New York State Mus. Bull. 49, p. 10, pl. 1, figs. 8, 9,
12-15, 17-20. (10?, 11?, 16?), 1901.—BASSLER, Cambrian and Ordovician: Maryland
Geol. Surv., p. 253, pl. 48, figs. 3-6 (1, 2?), 1919, repeats Ruedemann’s description and
figures.

This species has been widely but usually erroneously identified, because it has
the form and sculpture of a number of other stocks of plectambonitids such as
P. scissa Salter, P. transversalis (Wahlenberg), and P. gibbosus Winchell and
Schuchert. It is another interesting case of heterochronous homeomorphy. The
species as figured by Ruedemann appears to be composite and perhaps contains
more than a single genus. Wide and narrow forms are represented which are
probably conspecific, but the specimen represented by figures Io and 11 has very
different proportions from those given in the description and probably should
be excluded from the species.

In comparison with Bilobia hemisphaerica Ruedemann’s figures and specimens
from the gray crystalline limestone (Rysedorf conglomerate) in the National
Museum indicate that B. pisum is generally more strongly convex than the
Oranda species and the pedicle muscle area is smaller. One of the Rysedorf speci-
mens (fig. 17) has a curved furrow on the inside just anterior to the cardinal
extremity. This feature also appears on specimens from Guilford Springs, Pa.
It is less marked in the strongly rotund forms.

B. pisum comes from the black and gray crystalline limestone pebbles of the
Rysedorf conglomerate according to Ruedemann.

BILOBIA VIRGINIENSIS Cooper, new species
Plate 192, A, figures 1-5; plate 192, B, figures 6-15; plate 195, B, figures 6-8

Small, tumid, semicircular in outline, wider than long and with the greatest
width in the posterior half; sides moderately oblique to nearly straight. Anterior
margin narrowly rounded. Surface marked by costellae of unequal size, valves
differently marked. Pedicle valve with about 15 strong, threadlike costellae on
the front margin but only a few of them reaching the umbo, spaces between larger
costellae marked by a mat of fine costellae. Brachial valve covered by a mat of
fine, nearly even costellae.

Pedicle valve strongly convex in anterior and lateral profiles; posterior slope
steep and rounded; anterior slope longer but less steep than the posterior one;
lateral slopes long and steep. Umbo moderately swollen; median region tumid.
Interarea short, anacline.

Brachial valve deeply concave, with the maximum concavity just anterior to
the middle; anterior sulcate; anterior margins strongly bent in the direction of
the brachial valve. Cardinal extremities with short, narrow grooves to the ex-
terior. Interarea short, hypercline. Lobes of visceral disk long and narrow.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 763

Measurements in mm.—

Brachial Surface Mid- Hinge Thick-
Length length length width width ness Height

PIGlOty pe | .i'3. nays soe s 6.9 5.0 11.5 8.0 8.2 2.8 4.0
Paratype (117467c).. 6.9 5.6 11.5 8.1 8.0 2.7 3.9

Types.—Holotype: 117464a; figured paratypes: 117464b,c, 117465a,b,
117466a, 117467c ; unfigured paratype: 117465c.

Horizon and locality—Edinburg formation (Cyrtonotella zone) in Virginia:
Ravine at the switch just east of Strasburg Junction, Strasburg (15’) Quad-
rangle ; dam on north fork of the Shenandoah River, 13 miles N. 61° E. of Edin-
burg, Edinburg (15’) Quadrangle.

Botetourt formation in Virginia: On the south side of the road 0.2 mile east
of Strasburg, Strasburg (15’) Quadrangle.

Edinburg formation (lower Nidulites zone) in Virginia: From the cut on
U. S. Highway 11, just southwest of entrance to Battlefield Crystal Caverns,
1 mile northeast of Strasburg; Tumbling Run, 14 miles southwest of Strasburg ;
both in Strasburg (15’) Quadrangle.

Shippensburg formation (Pinesburg member—Echinosphaerites zone) in
- Pennsylvania: In the railroad cut 24 miles southwest of Marion, Chambersburg
(15’) Quadrangle.

Same formation in Maryland: In the cut on U. S. Highway 40, on the west
bank of Conococheague Creek, 7 miles west of Hagerstown, Williamsport (157)
Quadrangle.

Discussion —Bulobia virginiensis can be recognized by its small size but
strongly convex valves. It differs strongly from B. pisum and B. hemisphaerica
in size and has a much less swollen umbo, less inflated pedicle valve, stronger and
more crowded costellae. This species occurs in the Cyrtonotella zone and in the
lower part of the Nidulites zone of the Edinburg formation.

Subfamily LepTELLominaE Cooper, new subfamily

Plectambonitidae with elevated visceral disk.

Genus LEPTELLOIDEA Jones, 1928
Leptelloidea JoNEs, Mem. Geol. Surv. Great Britain, Palaeont., vol. 1, No. 5, pp. 388, 302,
1928.
LEPTELLOIDEA LEPTELLOIDES (Bekker)
Plate 188, E, figures 25-30

The figures of this genus and species are introduced for comparison with
Leptellina. Note difference in construction of cardinal process.

Types.—Hypotypes: 84257a-d.
Horizon and locality—Kuckers formation (C,a2): At Kohtla in Estonia.

764 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Family BIMURIIDAE Cooper, new family

Concavo-convex, smooth or lamellose Plectambonitacea with apical foramen
in pedicle valve ; simple cardinal process and 2 or 3 long divergent median septa
in the brachial valve.

Genus BIMURIA Ulrich and Cooper, 1942

Bimuria UtricH and Cooper, Journ. Paleont., vol. 16, No. 5, p. 622, 1942.

Shell moderately large reaching a width of about an inch, semicircular to semi-
elliptical in outline, concavo-convex in profile. Pedicle interarea curved, longer
than the brachial one, anacline; brachial interarea hypercline. Delthyrium in
well-preserved individuals partially closed by a short and rudimentary pseudo-
deltidium. Beak perforated by a tiny foramen. Umbonal region generally
smooth ; more or less of remaining surface covered by thin, wrinkled shell lamel-
lae. Shell structure pseudopunctate.

Pedicle interior with small, rudimentary teeth; dental plates obsolete ; diductor
and adjustor scars located at the base and sides of the delthyrial cavity ; diductor
scars large ; adductor scars indistinct. Vascula media strong, extending to about
the middle of an adult shell, then branching, the inner branches extending nearly
to the margin, while the outer ones arch slightly and extend nearly to the margin
where they again branch.

Brachial valve with elongate, slender, widely divergent brachial processes.
Chilidial plates strongly developed, attached to brachial processes and sides of
notothyrium by callus. Cardinal process simple, myophore slender or some-
what expanded, shaft short, united with a thin median septum that extends for
nearly the full length of the valve and is located between 2 slightly divergent
lateral septa. Lateral septa high and thin in the young, overgrown and nearly
obliterated in old shells by callus deposit on their inner and outer sides. Adduc-
tor impressions somewhat flabellate, located on the posterior portion of the callus
deposits on the outside of the lateral septa.

Genotype—Bimuria superba Ulrich and Cooper, Journ. Paleont., vol. 16,
No. 5, p. 623, pl. go, figs. 13-18, 1942.

Discussion.—Species of this genus have been assigned to Plectambonites=
Sowerbyella and Christiania. From the former it differs by its exterior and the
presence of the longitudinal lamellae inside the brachial valve. No taxonomic
relationship exists between Bimuria and Sowerbyella. Bimuria resembles Chris-
tiania in external form but is never so elongated as the species of that genus and
is usually lamellose whereas Christiania is smooth. The brachial interior of
Bimuria differs from that of Christiania in the possession of a simple cardinal
process rather than a rafinesquinoid, bilobed process such as is present in
Christiania.

Outside the United States in the Stinchar limestone of the Girvan District,
Scotland, Plectambonites ? youngiana (Davidson) is referable to Bimuria.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 765

BIMURIA BUTTSI Cooper, new species
Plate 212, B, figures 11-31

Christiania lamellosa Ulrich Ms. (not Bassler, 1919), Butrs, Alabama Geol. Surv., Special
Rep. 14, p. 116, pl. 26, figs. 31-34, 1926.

Shell of about medium size for the genus, slightly wider than long; hinge less
than the greatest width which is at the middle of old adults. Lateral margins
gently convex; anterior margin broadly to narrowly rounded. Umbonal region
of both valves usually smooth, remainder of surface covered by concentric
lamellae.

Pedicle valve moderately convex in lateral and anterior profiles. Umbo swol-
len. Anteriorly from the umbo a distinct but low fold is developed which ex-
tends to the anterior margin and produces a shallow sulcus there. Lateral slopes
moderately steep; posterolateral slopes abrupt and steep. Interarea strongly
curved, anacline.

Brachial valve strongly concave with the greatest depth in the midregion;
anterior portion sulcate; flanks bounding sulcus gently concave. Umbonal re-
gion deeply concave; interarea strongly hypercline.

Pedicle interior with small teeth, vascula media well impressed in adults;
other pallial marks less distinct. Inside the brachial valve lateral and median
septa well developed ; adductors located on callosities, and fairly well impressed.

Measurements in mm.—

Brachial Hinge Thick-
Length length Width width ness Height
FIOIOUYDE. Jaco s a cainy Sogs ee's ves 5g 15.6 12.0 18.5 15.2 4.0 6.8
Paratype (110032a with frills).. 18.4 15.0 21.9 16.2 47 9.2
f (a1eosah GAR. 14.4 II.0 15.6 123 4.0 6.9
- Gi Cee) ee ee 10.9 8.9 11.9 13.0 2.2 5.0
re CFESOOD) erccaiats Saieai sie > os 17.3 14.0 18.8 16.3 3.7 7.6

Types.—Holotype: 1109344, figured paratypes: 71506a, 110930a-d, 110932a,e,
110933a,c-e, 110934b,c, 110935a, 123264; unfigured paratypes: 71506b, 110930e,
110931, 110932b-d, 110933b, 110935b-e.

Horizon and locality.—Little Oak formation in Alabama: 4 mile northeast of
Pelham and 2 miles north of Pelham, Bessemer Iron District (15’) Quadrangle;
intersection of Bailey Gap road with main road 13 miles northeast of Newhope
Church, SW4iSW3 sec. 13, T. 19 S., R. 2 W., Vandiver (15’) Quadrangle.

Discussion.—The young of this species are generally considerably wider than
long and with the hinge forming the greatest width. With increasing age the
length increases at the expense of the width with the result that the old adult is
generally subquadrate to subcircular in outline. The hinge with increasing age
fails to grow lateraily. Consequently, in adult shells the hinge does not form
the widest portion of the valves.

This species suggests B. superba which it approaches in size, but it seldom
attains the large subquadrate form of the Tennessee species. The development
of a fold and sulcus are features lacking in B. superba. The fold and sulcus are
seldom very prominent in B. buttst, but they are, nevertheless, distinct. The

766 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

brachial interarea of B. buttsi is generally more hypercline than that of B. su-
perba. Therefore, the chilidial plates and cardinal process are brought more
fully into view in the Little Oak species.

BIMURIA IMMATURA Cooper, new species
Plate 211, A, figures I-13

Shell small, about twice as wide as long in the adults, cardinal extremities
rounded, auriculate. Anterior margin broadly rounded. Surface unornamented
except for concentric lamellae of growth and fine thin lamellae that cover much
of the shell.

Pedicle valve strongly convex with the greatest curvature in the region of
the umbo. Median region swollen; anteromedian portion somewhat swollen.
Front and lateral slopes moderately steep. Ears convex. Delthyrium very wide;
interarea short and pseudodeltidium rudimentary. Foramen open, in the form
of a short, oblique tube. Brachial valve deeply concave, following the curvature
of the pedicle valve closely, deepest in the median region; front and lateral mar-
gins inflected toward the brachial valve; ears concave. Interarea short, almost
orthocline in position. Chilidium short but wide. Umbo convex and forming a
small knob at the center of the valve.

Interior of pedicle valve with short and wide teeth; dental plates absent ; mus-
culature not visible. Inside the brachial valve 2 high, thin septa arise not far
anterior to the cardinalia, diverge gradually as they extend nearly to the front
margin. A small, median septum, thick but short, located between the 2 lateral
septa at their place of origin. Adductor muscles attached to elevated papillose
callosities on the outside of the lateral septa. Brachial processes rudimentary,
cardinal process absent.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Holotype Wierik. teks: 5.0 ? 6.3 7.0 ? 2.0
Paratype (110976a)..... 2.3 2.6 5.0 5.3 0.9 1.3
fs (t10976h) }):).4- Pa 2.5 5.0 4.7 ? 1.4
é (EIGO7OK) Oe jes 5.1 re 6.3 7.2 ts 1.9

Types.—Holotype: 110976g; figured paratypes: 110976i-k,m,n,p; unfigured
paratypes: 110976a-f,h,]l,o.

Horizon and locality Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Botetourt formation in Virginia: 3 to 4 miles east-northeast of Blacksburg ;
1.8 miles S. 4° W. of Bethel Church, 5.9 miles due east of Harrisonburg, Har-
risonburg (15’) Quadrangle.

Discussion.—This species is characterized by its small size, unornamented but
lamellose shells, and siphonate foramen. All these characters suggest young
Bimuria, but clear-cut evidence that such is the case has not been found.
Bimuria superba occurs in the Effna formation, but intermediate stages between
the largest of B. immatura and young B. superba have not been found. Further-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 767

more, considerable uniformity of size has been observed in B. immatura. For
these reasons it is preferred to regard the numerous specimens of this form in
the collection as a distinct species.

In addition to B. immatura two other species like it are known: One from
the Mystic conglomerate of Quebec, the other, B. siphonata, from the Pratt
Ferry formation of Alabama. The former species, B. matutina, has a much more
elevated umbo than the Effna form. Its interior is unknown, and it is possible
that the species may not be related generically to Bimuria. The Alabama species
differs in its slender, transverse outline.

BIMURIA LAMELLOSA (Bassler)
Plate 194, A, figures I-10; plate 212, A, figures I-10
Christiania lamellosa Basster, Cambrian and Ordovician: Maryland Geol. Surv., p. 257,
pl. 49, figs. 3-10, 1919.—Butts, Virginia Geol. Surv. Bull. 52, p. 109, pl. 95, figs. 7-10,
I .
C sae trentonensis brevis Butts, idem, fig. 1.

Shell small for the genus, wider than long with the greatest width slightly
anterior to the hinge. Cardinal extremities narrowly rounded. Lateral margins
gently rounded ; anterior margin broadly to narrowly rounded. Umbonal region
of both valves smooth; remainder of surface marked by more or less distant
concentric lamellae. Exfoliated shells appear to be smooth.

Pedicle valve strongly convex in lateral profile with the greatest convexity
at about the middle. Anterior profile forming a semicircle. Umbo swollen;
beak small, drawn into a sharp point. Foramen minute, located slightly posterior
to the apex of the beak. Valve strongly inflated with steep lateral and postero-
lateral slopes. Fold poorly defined, developed only in median region and near
the front. Interarea curved, strongly anacline.

Brachial valve deeply concave with the greatest concavity about at the middle.
Anterior to the middle a low, not well defined sulcus indents the commissure
toward the brachial valve. Interarea well developed, hypercline to orthocline.
Notothyrium closed by a thick and large chilidium.

Brachial processes widely divergent, thin, defining deep sockets for the teeth.
Cardinal process a simple ridge, nearly obsolete and poorly defined in the
extreme posterior part. A low ridge extends anterior to the rudimentary process
nearly to the anterior margin. This ridge is highest at the place where the 2
divergent septa originate and extends between them. Outside each septum is
a papillose lobate area on the posterior portion of which the adductor muscles
were attached. The outside of these lobate areas is elevated above the floor of
the valve.

Measurements in mm.—

Brachial Hinge
Length length width Width Thickness Height

THectotype "snc fn. cae 10.4 WEG Liey, 10.9 2.2 5.2
Paratype (66168c).... 10.7 8.1 11.9 10.0 2.5 4.6

768 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Lectotype: 66168a; paratypes: 66168b-d; figured hypotypes:
110948a-c,f, 110949a,c.

Horizon and locality—Oranda formation in Strasburg (15’) Quadrangle,
Virginia: In the railroad cut $ mile west of Strasburg; on U. S. Highway 11,
from 4 to 2 miles southwest of Strasburg; on Virginia Highway 55, 0.4 mile
west of U. S. Highway 11, north edge of Strasburg.

Same formation in Pennsylvania: 1 mile northwest of Guilford Springs,
24 miles southwest of Chambersburg, Chambersburg (15’) Quadrangle.

Discussion—This species is more transverse and never attains the large size
reached by B. superba and B. buttsi. It was originally confused with Christiania
and under that term lent an erroneous name to a stratigraphic zone. Inasmuch
as the Oranda formation is nearly synonymous with the Christiania or Bimuria
zone, it is really not necessary to use the generic names.

Bimuria lamellosa is a fairly small species which will not be confused with
B. buttsi or B. superba. It is not unlike B. parvula but differs in its larger size,
stronger and more inflated umbo, and more completely lamellose exterior.

BIMURIA ? MATUTINA Cooper, new species
Plate 210, C, figures 6-10

Small, resembling B. immatura, wider than long with the greatest width at or
near the hinge; sides oblique, gently rounded ; anterior margin broadly rounded ;
surface smooth in the decorticated condition but showing traces of lamellae in
distant, elevated concentric lines.

Pedicle valve moderately strongly convex, flattened in the anterior third and
narrowly rounded on the umbo; anterior profile with median region strongly
humped and with long, moderately steep and gently concave lateral slopes. Um-
bonal and median regions strongly swollen, the swelling continued anteriorly but
in diminishing degree to the front margin. Sides depressed and with moder-
ately steep anterolateral slopes. Foramen and interarea not observed; interior
unknown.

Brachial valve deeply concave, with the deepest part at or just posterior to
the middle. Concavity occupying most of valve and resulting anterior margin
strongly reflected in the direction of the brachial valve. Cardinal extremities
concave. Interior unknown.

Measurements in mm.—
Brachial Hinge Thick-

Length length Midwidth width ness Height
Holotype: s .22l) .ahsiets. <2 4.9 ? 6.5 oi) ? 2.3
Paratype (66288a)...... 5.7 2 8.3 8.8? ? 21
¥ (66288e)iifo 5. ? 4.1 6.7 7.4 ? ?

Types.—Holotype: 66288b; figured paratype: 66288a; unfigured paratypes:
66288c-g.

Horizon and locality—Boulder in the Mystic Conglomerate in Canada: On
Range 6, Lot 20, Stanbridge Township, near Mystic, Quebec.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 769

Discussion.—This is a small species occurring in fairly hard limestone boulders
in the Mystic conglomerate. The matrix has defied preparation of pedicle in-
teriors because the internal details of that valve are only lightly impressed at
best in other species of Bimuria comparable to this one. No specimens of the
brachial valve appear in the collection except ones preserving an impression of
the exterior. It was thus impossible to obtain the brachial interior by burning
off the shell.

This species is most like B. immatura but differs in attaining a larger size
than any yet noted for the Virginia species. The median swelling is narrower
than that of B. immatura and the flanks thus more depressed. The flanks are
also somewhat narrower than in the Virginia species. The Quebec species is
larger than, and different in shape from, B. siphonata from Alabama.

BIMURIA PARVULA Cooper, new species
Plate 184, B, figure 4; plate 210, A, figures 1-4

Small for the genus, wider than long, with the greatest width at about the
middle; sides gently convex; anterior margin broadly rounded; anterior com-
missure narrowly sulcate. Width of hinge slightly less than the maximum shell
width; surface mostly smooth but anterior half of some specimens showing
traces of thin lamellae.

Pedicle valve strongly convex in lateral profile and with a swollen umbo
which is the most convex part; anterior profile broadly and strongly convex
with moderately long and steep lateral slopes. Median region swollen; anterior
slope long and moderately sloping; posterior slope narrowly rounded; beak visi-
ble only from the brachial side, foramen small in the adult, produced into a short,
narrow tube in the young adult and immature shell. Interior with wide, short
teeth ; muscle area not discernible. Interarea short, anacline.

Brachial valve deeply concave, the maximum concavity located just posterior
to the middle ; lateral regions less shallow than the median region ; posterolateral
areas somewhat flattened. Interior with widely divergent brachial process;
median septum highest in the posterior third or quarter; lateral septa strongly
elevated and with thick callosities on the side away from the middle.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Holotype stare eaeee es ee 3.6 7:2 6.1 1.5 2.3
Paratype (117469a)..... 7.0 ? 8.8 6.8 ? 2.8
s (117469b)..... 6.1 4.9 a7 6.6 1.5 2.5

Types.—Holotype: 117469d; figured paratypes: 117469e,f, 123253a; un-
figured paratypes: 117469a-c.

Horizon and locality—Chatham Hill formation in Virginia: On northwest
slope of Walker Mountain, 1.2 miles S. 31° E. of Sharon Springs, Burkes
Garden (15’) Quadrangle.

Edinburg limestone (Cyrtonotella zone) in Virginia: On the south side of

770 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the road, 0.2 mile east of Strasburg; about 4 mile south of Strasburg Junction;
ravine at switch just east of Strasburg Junction; all in Strasburg (15’) Quad-
rangle. Collier Creek, $ mile north of the junction of Virginia County Highways
251 and 612, about 6 miles west-southwest of Lexington, Rockbridge County.

Shippensburg formation (lower 50 feet above New Market limestone) in
Pennsylvania: In the field just north of the east end of the railroad cut 2 miles
southwest of Marion Station, Chambersburg (15’) Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: Cut at the crossing
of U. S. Highway 50 over Opequan Creek, southeast of Winchester, Winchester
(15’) Quadrangle.

Discussion.—This species, although small in size, is larger than B. immatura,
B. matutina, or B. siphonata. It is really intermediate between these and B. la-
mellosa. It is not so strongly umbonate as the latter and is generally not so
strongly or so completely lamellose as the Oranda species. It is much smaller
in size than either B. buttsi or B. superba.

BIMURIA SIPHONATA Cooper, new species

Plate 210, G, figures 17-24

Shell small, transversely semielliptical, with the hinge equal to or slightly less
than the greatest width; posterolateral extremity somewhat rounded ; sides gently
rounded, somewhat oblique; anterior margin broadly rounded; posterior half to
three-quarters usually smooth, anterior half to quarter often with thin concen-
tric lamellae.

Pedicle valve strongly and fairly evenly convex in lateral profile, the umbo
forming the most rounded part; anterior profile forming a strongly convex,
broad arch with evenly and moderately steeply sloping sides. Umbo swollen ;
median region and sides strongly inflated giving the entire valve a fairly even
convexity ; beak provided with a narrow siphon projecting directly posteriorly
or inclined somewhat toward the pedicle valve and narrowing distally to form
a tiny foramen; delthyrium open; muscle impressions too lightly impressed to
be discernible or individualized.

Brachial valve deeply and broadly concave, sharing the even convexity of the
pedicle valve ; interarea with rudimentary chilidial plates and a small transverse,
flat plate at the apex. Cardinal process not formed; brachial processes slender,
extending along edge of palintrope ; median septum short, highest at point where
lateral septa originate a short distance anterior to the apex; lateral septa low,
moderately divergent and extending onto anterior slope; adductor scars located
outside the septa and forming fimbriated lobe which is divided unevenly by a
low, oblique ridge.

Measurements in mm.—

Length
Brachial Mid- Hinge Thick- of
Length length width width ness Height siphon
BIOIGtV Es aS acs noes 2.0 1.9 4.4 4.4 ? 0.9 0.25

Paratype (117470d).. 2.6 2.0 5.0 5.4 ? 1.5 0.40

PART... £ CHAZYAN AND RELATED BRACHIOPODS—COOPER 771

Types.—Holotype: 117470a; figured paratypes: 117470d,e; unfigured para-
types: 117470b,c,f.

Horizon and locality.—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This species is suggestive of B. immatura and B. matutina in its
small size and apparently immature characters. It differs from both of them,
however, in the form and outline of the pedicle valve. The Quebec and Virginia
species are strongly swollen medially and have somewhat depressed sides, par-
ticularly B. matutina. The species from the Effna limestone is somewhat nasute
and is much less transverse than the B. siphonata.

Bimuria siphonata shows immature characters in its small size, lack of thicken-
ing of the adductor muscle field, and the presence of a pedicle siphon. The
Pratt Ferry limestone to date has not yielded a normal adult of Bimuria, but
hundreds of valves of about the same size of B. siphonata have been obtained
from it. These facts suggest that the species may actually be an adult which
retains some of its juvenile characters.

BIMURIA SUPERBA Ulrich and Cooper
Plate 184, C, figure 5; plate 210, B, figure 5; plate 210, F, figures 15, 16;
plate 210, I, figures 33, 34; plate 211, B, figures 14-25

Bimuria superba Utricn and Cooper, Journ. Paleont., vol. 16, No. 5, p. 623, pl. 90, figs. 13-18,

1942.
Christiania cf. C. lamellosa Butts (not Bassler), Virginia Geol. Surv. Bull. 52, p. 42, pl. 73,
figs. 34-36, 1942.

Shell large, subcircular in outline, varying from slightly wider than long, to
slightly longer than wide; cardinal extremities varying from a right angle to a
slightly obtuse angle. Lateral margins nearly straight to gently convex; anterior
margin broadly rounded. Profile concavo-convex with the pedicle valve strongly
convex and its beak overhanging the brachial interarea. Surface generally nearly
completely covered by fine, wrinkled, crowded, concentric lamellae.

Pedicle valve strongly convex in lateral profile and with the greatest con-
vexity at about the middle. Umbo strongly swollen. Anterior profile strongly
convex. Lateral and anterior slopes abrupt and steep. Posterolateral slopes
steep and slightly concave. Interarea strongly concave, anacline in position.

Brachial valve deeply concave with the greatest concavity at about the median
region. Interarea strongly hypercline. Umbonal and median regions deeply
concave.

Interiors as described for the genus.

Measurements in mm.—Holotype, length 19.7, brachial length 14.8, width
22.2, hinge width 18.4, thickness 5.4, height 8.5.

Types.—Holotype: 108200a; figured paratypes: 108200b,c,f, 108201; un-
figured paratypes: 108200d,e,g-j; figured hypotypes: 110964a, 110981, 117471,
117472a.

Horizon and locality—Arline formation in Tennessee: On both sides of old

772 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

road in glade, 4 mile southeast of Friendsville, Concord (T.V.A. 138-SW)
Quadrangle; 4 mile south of McMullens, Meadow (T.V.A. 139-NW) Quad-
rangle; 1,500 feet south of the mouth of Burnett Creek, Shooks Gap (T.V.A.
147-NE) Quadrangle; small quarry 4 mile northeast of St. Clair, Bulls Gap
(T.V.A. 171-SE) Quadrangle; 1 mile northeast of Friendsville, Louisville
(T.V.A. 138-SE) Quadrangle; 6 to 10 miles southeast of Loudon; 54 miles
southeast of Knoxville.

Tellico formation in Tennessee: On the south side of Chapman Highway
(Tennessee Highway 71), 0.3 mile N. 10° W. of Pitner School, Walden Creek
(T.V.A. 156-SW) Quadrangle.

Arline formation in Virginia: In the quarry at the railroad station in Marion,
Marion (T.V.A. 218-SE) Quadrangle.

Botetourt formation in Virginia: On Virginia Highway 114, 2.3 miles west
of the Montgomery-Roanoke County line, 12 miles northeast of Blacksburg.

Effna formation in Virginia: In Porterfield Quarry, 5 miles east of Saltville,
Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion—Bimuria superba is the largest of the known American species
of Bimuria. It is characterized by its large size, attaining nearly an inch in
width, and its generally subquadrate form. Its nearest relative is B. buttsi from
which it differs in not having the wide hinge and oblique sides in the younger
stages and by attaining a larger size than that reached by B. buttsi. The umbo
of B. superba is not so elevated and narrowly convex as that of B. butts.

BIMURIA sp. 1
Plate 210, FE, figures 12-14

A single fragmentary specimen of moderate size was found in the dark shaly
rock under the Eureka quartzite on the north-facing nose of hill 8167, Martins
Ridge, Monitor Range, Nev. The specimen is somewhat suggestive of B. lamel-
losa Bassler, but it is not well enough preserved to be definitely so identified.

Figured specimen.—117473.

CRASPEDELIA Cooper, new genus

(Greek kraspedon, border of a garment)

Shell small, resembling small Bimuria; strongly concavo-convex; transverse
and with the hinge equal to or greater than the widest part; surface smooth;
pseudopunctate.

Pedicle valve with swollen umbo and median region; foramen produced into
a short siphon; interarea short, anacline; teeth short and wide; dental plates
absent; other details of the interior not discernible. Anterior margin deflected
toward the pedicle valve to form an elevated rim that fits inside a similar rim
on the brachial valve.

Brachial valve with anterior margin deflected in the direction of the pedicle
valve to form a high rim which fits outside the edge of the pedicle valve; inter-
area hypercline ; chilidial plates small. Brachial process small, widely divergent
and adhering closely to the palintrope edge. Median septum rising to a crest a

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 773

short distance anterior to the cardinalia, extended anteriorly as a low ridge or
dying out; lateral septa narrowly divergent anteriorly, an elevated and an-
teriorly fimbriate adductor platform appearing on the outside of the septa.

Genotype.—Craspedelia marginata Cooper, new species.

Discussion —This genus is closely related to Bimuria as shown by the interior
structure of both valves. Pedicle valves show a suggestion of a siphonate fora-
men, but the specimens are more adult in their characters than B. immatura and
B. siphonata with which it occurs. The deflected margins are clearly an adult
character, and the genus may be regarded as an arrested off-shoot of the main
Bimuria stock.

The interior of the brachial valve in its adductor callosities also suggests an
adult shell. These callosities are elevated in some instances to the same degree
as the visceral disk of Leptellina and Bilobia. In this respect Craspedelia differs
strongly from Bimuria. It is interesting to note that the adaptation of this shell
as exhibited by the deflected margins is very much like Xenambonites.

CRASPEDELIA MARGINATA Cooper, new species
Plate 213, A, figures 1-20

Shell small, transverse with the hinge forming the widest part; cardinal ex-
tremities alate; lateral margins strongly oblique, gently convex; anterior margin
broadly rounded. Surface smooth.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity at the umbo; anterior profile strongly humped in the middle with steep
slopes to the depressed flanks. Median region narrowly swollen and much ele-
vated above the narrow, gently convex flanks. Marginal deflection not strongly
elevated. Region immediately posterior to deflected rim forming a narrow trough.

Brachial valve deeply concave in the median region; lateral extremities sul-
cate but shallow; anterior part bounding concave median area steeply deflected
toward the margin of the brachial valve; anterior margin deflected toward the
pedicle valve, the deflected area attaining a length of more than 1 mm. Deflected
margin enclosing the similar area in the pedicle valve.

Measurements in mm.— Eeiten
Brachial Hinge deflected

Length length Midwidth width Height rim

Paratype (117474a).... 4.4 ? 6.6 7.4 2.0 0.75

iy (1874740). 0!. Set ? 5.0 6.2 1.9 0.90

+ CLpzarawy eG. oc) P 3.1 6.0 7.0? ? 1.70

Types.—Holotype: 117474b; figured paratypes: 117474a,c-f; unfigured para-
types: 117474g-0.

Horizon and locality——Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This species is like Bimuria matutina or B. immatura in the
exterior form of the pedicle valve but differs in having the strong anterior rims.
It differs internally from B. immatura in the different development of the callosi-
ties of the adductor field.

774 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Family SOWERBYELLIDAE Opik, 1930

Plectambonitacea having a simple cardinal process united to the brachial proc-
esses, giving the cardinalia the shape of an inverted V.

Subfamily SowERBYELLINAE Opik, 1930

Sowerbyellidae having 2 or more septa in the brachial valve.

Genus SOWERBYELLA Jones, 1928

Sowerbyella Jones, Mem. Geol. Surv. Great Britain, Paleont., vol. 1, No. 5, pp. 384, 302,
1928.

SOWERBYELLA AEQUICOSTELLATA Cooper, new species
Plate 199, B, figures 9-17

Moderately large, length equal to about two-thirds the width. Cardinal ex-
tremities somewhat rounded, slightly acute or approximating a right angle. Lat-
eral margin gently convex ; anterior margin broadly rounded. Anterior commis-
sure rectimarginate. Surface multicostellate; costellae narrowly rounded, sepa
rated by narrower interspaces. Costellae of nearly equal size. A few stronger
than the surrounding ones are scattered on the surface. Costellae numbering
about 24 to 30 in 5 mm. at the front margin.

Pedicle valve strongly convex in lateral profile and with the greatest con-
vexity posterior to the middle. Anterior profile with the greatest convexity at
the middle and with the lateral slopes flat and moderately steep. Beak incon-
spicuous, protruding very slightly beyond the posterior margin. Umbonal and
median region inflated. Lateral areas moderately inflated with the slopes to the
cardinal extremities short and moderately steep. Interarea long, curved, gently
anacline.

Brachial valve moderately concave with the greatest concavity at about the
center but becoming concave anteriorly. Flanks gently concave. Interarea mod-
erately long, hypercline.

Interior: Pedicle valve with median ridge separating diductors short and
stout, expanding anteriorly; diductor impressions large, widely divergent; ad-
ductor impressions small. Cardinal process of brachial valve large, septa low,
strongly elevated at about the middle of the valve ; adductor impressions thickened
to form a low platform. Anterior half strongly spinose.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness Height
EVOLOEY PE...» <Pdisisialevepeyererss 9.2 ee Tgi2 13.2 2.0 3.0
Paratype (117477a)... 7.3 ? 11.7 12.2 ? ?
a (117477b)... 8.6 ? 137 13.5 fe G
AA (117477c)... 8.0 ? 13.2 13.6 ? ?
es (174770)... 7 8.7 14.3 14.5 ? ?
¥ (117477g)... 8.5 viel 13.4 12.6 2.6 3.5

Types.—Holotype: 117477{; figured paratypes: 117476a, 117477a,b,d,e,g ; un-
figured paratypes: 117476b-d, 117477¢,h.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 775

Horizon and locality—Edinburg formation (Cyrtonotella bed) in Strasburg
(15’) Quadrangle, Virginia: In the ravine at the switch } to + mile east of Stras-
burg Junction; Tumbling Run, 14 miles southwest of Strasburg.

Edinburg formation (Nidulites zone) in Strasburg (15’) Quadrangle, Vir-
ginia: On U. S. Highway 11 about 1 mile north of Strasburg ; along Tumbling
Run, 14 miles southwest of Strasburg.

Shippensburg formation (50 feet above base of Pinesburg member) in Mary-
land: On U. S. Highway 40, on the west bank of Conococheague Creek, 7 miles
west of Hagerstown, Williamsport (15’) Quadrangle.

Same formation in Pennsylvania: At the east end of the railroad cut and
adjacent field to the north, 24 miles southwest of Marion, Chambersburg (15’)
Quadrangle.

Discussion——Moderately strong and subequal costellae characterize this
species. The shell is generally of moderate size and fairly low convexity. It is
most like S. cava from the Oranda and Salona formations but differs in attaining
a somewhat greater size, interareas less bent anteriorly, and considerably less
convexity. This is not a common species in the lower Edinburg formation.

SOWERBYELLA AEQUISTRIATA (Willard)
Plate 197, C, figures 25-34

Plectambonites aequistriatus WiLLARD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 276, pl. 3, figs. 8, 9, 1928.

About medium size for the genus, wider than long, semielliptical in outline;
cardinal extremities nearly a right angle and with the extremities drawn into
tiny ears. Sides nearly straight to gently rounded; anterior margin broadly but
strongly rounded. Costellate, costellae at front of pedicle valve generally alter-
nating large and fine but on brachial valve usually more equal in size. About
5 costellae to the millimeter on the pedicle valve and 7 to the millimeter at the
front margin of the brachial valve.

Pedicle valve evenly and gently convex in lateral profile, with the maximum
convexity at about the middle; anterior profile with the median region some-
what narrowly convex but with the sides descending in long, only moderately
steep slopes to the margins. Beak small, umbo narrowly swollen and with the
swelling continued anteriorly as a poorly defined fold. Flanks flat to gently con-
cave. Interior with the diductor scars diverging at about 80° and separated by
a short median ridge.

Brachial valve gently concave; umbo concave, the concavity extended an-
teriorly as a shallow and narrow sulcus; flanks gently concave. Interior with
septa slightly divergent and forming a crest at about two-thirds the length from
the beak. Adductor field thickened at the front.

Measurements in mm.— Brachial Hinge
Length length Midwidth width Thickness Height
Hypotype (117478f).. 9.3 8.6 13.0 13.2 1.7 2.5
‘ (117478g).. 9.9 9.1 14.8 1731 2.0 3.8

ee (117478a).. 10.4 9.7 13.2 14.1 1.8 2.5

776 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types—Figured hypotypes: 117478a,b,f,g; unfigured hypotypes: 117478c-e.

Horizon and locality—Wardell formation in Tennessee: Along the railroad
just west of Liberty Hill, Dutch Valley (T.V.A. 154-SE) Quadrangle; 0.3 mile
east of Mason’s store, Bristol (30’) Quadrangle; near the south end of Chicka-
mauga Dam, 7 miles upstream from Chattanooga, East Chattanooga (T.V.A.
112-SW) Quadrangle.

Discussion.—This species is characterized by a subrectangular to subquadrate
outline, fine costellae, and moderate convexity, and is like several others found
in the Appalachian Valley. The ornamentation and proportions are like those
of S. multicostellata, but the size attained is generally greater than that reached
by the latter species. S. multicostellata is usually a much deeper shell. Sower-
byella socialis approaches this species in form but is more strongly costel-
late and has a more prominent development of the beaded costellae. Sower-
byella lebanonensis does not attain the large size nor the somewhat quadrate
form of S. aequistriata.

SOWERBYELLA ANGULATA Cooper, new species
Plate 206, A, figures 1-7
Sowerbyella curdsvillensis Butrs (not Foerste), Alabama Geol. Surv., Special Rep. 14,
p. 130, pl. 33, figs. 5, 6, 1926.

Shell large for the genus, subrectangular in outline; hinge forming widest
part; cardinal extremities acutely angular to auriculate; sides oblique; antero-
lateral extremities broadly rounded; anterior margin nearly straight; costellae
strong, not strongly differentiated in size at the front margin, 3 to 5 in a milli-
meter at the front margin. A few strong wrinkles along the posterior margin.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity in the median region; anterior profile strongly and broadly arched ; lateral
slopes moderately long and steep; beak and umbo inconspicuous; median region
strongly swollen; anterior slope convex and steep; median region marked by a
narrow, indistinct median fold. Interarea long and strongly apsacline; ae |
deltidium short.

Brachial valve deeply concave in the median region, the concavity lessening
laterally ; posterolateral extremities somewhat flattened.

Pedicle interior with broad diductor scars bounded posterolaterally by mod-
erately strong ridges. Brachial interior with 3 strong median septa, the median
one almost as prominent as the lateral ones. Subperipheral rim not strongly
thickened.

Measurements in mm—

Brachial Hinge Thick-
Length length Midwidth width ness Height
1 (re (0) 5) eR Pe ea 12.5 11.3 18.2 22.6 3.5 5.4
Paratype (71538)... ... 12.3 II.1 18.3 20.7 3.2 4.5
C7TRIOCT ae caet 11.2 9.8 17.9 19.4 aE 4.6
s CEITZAZOA) o enistos 10.6 9.5 16.9 20.5 3.0 4.5

os CIUTTAFOD Nice wees ? Gags. es 19.0 ry ?

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 74

Types.—Holotype: 71538a; figured paratype: 117479b; unfigured paratypes:
71538b,c, 117479a,c-e.

Horizon and locality—Hermitage formation in Alabama: On Cliff Avenue,
Clifton Terrace, Birmingham, Birmingham Special (15’) Quadrangle.

Discussion.—This species is characterized by its transversely subrectangular
outline, angular cardinal extremities and somewhat truncated front margin. It
is obviously related to S. curdsvillensis but differs importantly from that species.
It is more angulated in appearance, is much more convex and therefore with a
more deeply concave brachial valve.

SOWERBYELLA BELLARUGOSA Ulrich and Cooper
Plate 196, E, figures 27-29

Sowerbyella bellarugosa Utricu and Cooper, Geol. Soc. Amer. Special Pap. 13, p. 186,
pl. 38A, figs. 1-3, 1938.

Types.—Lectotype : 92867e ; paratypes: 92867a-d,f-l.
Horizon and locality—Upper Pogonip group in Nevada: Ikes Canyon,
Toquima Range, Roberts Mountains (1°) Quadrangle.

SOWERBYELLA CAVA Cooper, new species
Plate 203, C, figures 21-30; plate 203, D, figures 31-43
Sowerbyella sp. ? Virginia Geol. Sury. Bull. 52, pt. 2, p. 100, pl. 95, figs. 18-21, 1942.

Small, strongly convex, length about two-thirds the width; hinge equal to or
slightly less than the greatest width; sides gently rounded, moderately oblique
to nearly straight depending on age; cardinal extremities somewhat rounded or
nearly a right angle. Anterior margin broadly rounded, often faintly nasute.
Costellae variable on both valves, those of the brachial valve appearing closely
crowded, those of the pedicle valve somewhat more distantly spaced. Costellae
of unequal size and unequal in spacing, a larger and smaller one alternating or
3 or 4 alternating with larger costellae. About 5 or 6 costellae to the millimeter
at the front margin of an adult.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity at about the middle; anterior profile strongly convex in the median region
and with steeply sloping sides. Umbo low, somewhat swollen and in many speci-
mens forming a low, narrow fold more or less indistinctly extending to the an-
terior margin; median region of middle and anterior parts of valve strongly
swollen; sides steep; anterior slope long and steep; posterolateral extremities
only slightly flattened. Interarea gently anacline. Pseudodeltidium short. Beak
visible from the side of the brachial valve, protruding slightly over the interarea.

Brachial valve deeply concave especially from the umbo to the front margin
which is slightly indented; umbo deeply concave; anterior and lateral portions
dipping steeply toward the middle; posterolateral extremities gently concave.
Interior with slightly divergent septa rising to a high crest at midwidth; anterior
slope of crest steep ; muscular field transversely elliptical ; lateral scars the larger ;
inner margin thickened and strongly granulose just inside the periphery.

778 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
FUGlotypescs + + vacant et 8.8 7.4 12.3 12.3 23 4.2
Paratype (117481a).. 8.6 7.4 11.9 13.0 2.4 3.9
(11748Ic).. 7.5 6.3 10.8 11.4 2.0 3.4
= (117481d).. 7.4 6.2 10.3 10.6 2.0 3.6
FS (117481e).. 8.3 6.8 15.5 11.0 2.3 3.8

Types.——Holotype: 117481b; figured paratypes: 117480a, 117481a,e,f;
123258a-c; unfigured paratypes: 117480b-d, 117481c,d.

Horizon and locality—Oranda formation in Virginia: 0.6 mile northwest of
Linville Station, Broadway (15’) Quadrangle; along the railroad 4 mile west
of Strasburg, Strasburg (15’) Quadrangle; just west of the junction of Virginia
County Highways 617=910, and 777, 4 mile north of Green Mount Church,
Broadway (15’) Quadrangle.

Basal Martinsburg formation (part with Brongniartella=Salona) in Virginia:
On Virginia County Highway 617=910, 0.15 mile north of Green Mount
Church, 4 to 5 miles north of Harrisonburg, Broadway (15’) Quadrangle.

Salona formation in Pennsylvania: On Fishing Creek, north edge of Salona,
Lock Haven (15’) Quadrangle.

Discussion.—This species suggests S. aequicostellata in its general configura-
tion and ornamentation. The two species also occur in faunas that are obviously
related. Sowerbyella cava is much more convex, is less transverse, and has more
prominent cardinal extremities than S. aequicostellata.

SOWERBYELLA COMPACTA Cooper, new species
Plate 196, H, figures 51-59; plate 197, B, figures 11-24; plate 200, A, figures 1-6;
plate 202, A, figures 1-8

Shell about medium size for the genus, wider than long with the length equal
to about two-thirds the width. Cardinal extremities slightly acute or approxi-
mately rectangular, often auriculate. Lateral margins indented just anterior to
the cardinal extremities, extending nearly straight or moderately obliquely to the
anterolateral margins; anterior margin broadly curved. Anterior commissure
rectimarginate to sulcate. Surface ornamented by costellae of nearly equal size,
about 120 in number and 6 or 7 in 1 mm. at the front margin of an adult. In
addition to these the costellae are provided with small crescentic beads and the
interspaces are marked by fine concentric fila; on each side of the beak and just
anterior to the posterior margin many specimens show 4 or 5 oblique wrinkles.

Pedicle valve having a moderate convexity in lateral profile with the greatest
convexity at about the middle; in anterior profile it forms a low arch highest
in the middle and with the sides sloping moderately steeply to the margins. Beak
inconspicuous, umbo narrowly swollen, produced forward as a more or less dis-
tinct fold that may or may not reach the anterior margin. Valve full in mid-
region, slopes to anterior and lateral margins moderately steep. Interarea slightly
curved, moderately long and strongly apsacline. Pseudodeltidium small.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 779

Brachial valve moderately concave with the most concave portion between
the umbo and the middle; posterolateral areas deflected and flattened. Areas
bounding deepest concave portion only gently convex. Median sulcus reaching
the margin in some specimens, in others the anterior portion distinctly flattened.
Interarea hypercline.

Pedicle interior with large, subflabellate, widely divergent adjustor-adductor
impressions; median septum short, forked. Interior thickened and with deeply
impressed pallial marks. Brachial valve with much thickened and wide periph-
eral border ; median septa low, ending at about middle of valve where they are
moderately elevated.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness Height
FGLoty Ne tAtleitees.ci4 6.9 6.6 10.2 DTT 1.4 2.0
Paratype (117487b)... ? 6.7 9.3 g.1 ? ?
y (IL74AS7C)-. 7.0 7 10.5 10.7 1.8 2.5
* (117487d)... 7.8 a3 10.5 II.I 2.0 2.2
s (117487e) ..... 6.9 6.6 9.9 10.3 1.8 2.1
ie CUTZAS7i) ee) 7.0 6.5 9.4 0.3 1.8 1.9
ss (117489a)... 7.8 7.4 11.9 12.4 1.8 2.9
ms (117486a)... 7.2 6.6 Ei.2 12.5 1.6 2.2
si (117486c)... 6.6 6.3 10.0 11.7 3 24
rf (117484a)... 6.0 5.6 8.2 8.7 1.5 1.8
ic (117484b)... 7.2 6.6 9.0 9.5 23 2.6
% (117483b)... 8.4 ? 12.0 12.6 ? 2.5
* (aI7483a ys Pr 8.0 12.8 14.3 ? ?
“ (117483f) ... 8.3 ? 12.4 133 ? 2.4
is CELZAS IO ican vite? 8.1 12.8 12.6 ? ?
5 (117490).... 8.6 8.0 12.3 12.8 ? 1.9 2.5

Types.—Holotype: 117487a; figured paratypes: 117483b,c, 117484a-d,
117485a,b, 117486a-c, 117487b, 117490; unfigured paratypes: 117482, 117483a,
d-f, 117487c-i, 117489a.

Horizon and locality —Benbolt formation in Virginia: 1 mile west of Rye Cove,
second cut west of McDavid’s house; 0.3 mile north-northwest of the Memorial
School, Rye Cove; at the Brick Church 14 miles west of Rye Cove; 1 mile west
of Rye Cove; Clinchport (T.V.A. 188-NW) Quadrangle. 0.2 mile south of the
middle fork of Moccasin Creek, 14 miles due south of Hansonville, Hansonville
(T.V.A. 205-SW) Quadrangle; north side of U. S. Highway 19, 13 miles south-
east of Hansonville Post Office, Brumley (T.V.A. 205-SE) Quadrangle; east
bank of sinkhole 300 feet south of Lakeview Church, on Virginia Highway 71,
Moll Creek (T.V.A. 196-SE) Quadrangle.

Dryden formation in Tennessee: Lone Mountain, 1 mile west of Lone Moun-
tain, and 14 miles northeast of Lone Mountain, Tazewell (T.V.A. 154-NE)
Quadrangle; Tennessee Highway 53 at Nicely and Palmer’s store, 4 mile east
of Kate, Maynardville (30’) Quadrangle. Roadside 0.9 and 1.6 miles northeast
of Heiskell; road corner 4 mile southwest of Fleanor Mill, Powell Station
(T.V.A. 137-SE) Quadrangle. West side of sharp loop of the road down Flint

780 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Creek, center subquad., Powder Springs (T.V.A. 154-SW) Quadrangle; Syca-
more Creek, northwest corner Maynardville (T.V.A. 145-SE) Quadrangle;
north side of Lone Mountain Creek, just west of the road to Straight Creek,
0.8 mile west of Lone Mountain Station, Tazewell (T.V.A. 154-NE) Quad-
rangle.

Type Ottosee shale (= Benbolt formation) in Tennessee: At Chilhowee Park,
north side of Knoxville, Knoxville (T.V.A. 147-NW) and Fountain City
(T.V.A. 146-SW) Quadrangles.

Discussion.—This is a somewhat variable species, some of the specimens hav-
ing a fairly quadrate form whereas others are distinctly subrectangular. The
species is characterized by moderate convexity and concavity, the common sower-
byelloid habit, but marked by very fine costellae, 6 or 7 to the millimeter. The
species is much like S. socialis in form and contours but differs in having much
finer costellae. Sowerbyella lebanonensis is suggestive of this species but has
costellae more distinctly differentiated into fine and strong and is a more trans-
verse shell having a length/width index of 0.62 to 0.67, whereas that of S. com-
pacta is 0.64 to 0.80 and with an average near 0.70.

SOWERBYELLA CURDSVILLENSIS (Foerste)
Plate 201, A, figures 1-13
Plectambonites curdsvillensis Forrste, Bull. Sci. Lab., Denison Univ., vol. 17, p. 122, pl. 10,
figs. 15A, B, 1912.

In describing this species Foerste failed to give any details of the exterior.
His description emphasizes the subperipheral border and the small pallial dis-
tributaries extending anteriorly on its surface. This species is a large form with
beaded costellae like S. punctostriata. The following characters of the exterior
are important: Wider than long, with the cardinal extremities nearly a right
angle; auriculate in the young; subrectangular; sides nearly straight to moder-
ately oblique ; anterior margin broadly rounded to nearly straight. Pedicle valve
fairly strongly convex in lateral profile; broadly convex in anterior profile; lat-
eral slopes long and moderately steep. Brachial valve moderately deeply con-
cave ; flanks gently concave to somewhat flattened.

Inside the pedicle valve the diductor scars are long and separated by a median
ridge extending nearly to the valve middle; vascula media broad. Brachial in-
terior usually with thickened subperipheral rim, well-defined septa and wide ad-
ductor field with elevated rim marking its outer boundaries.

Types.—Figured hypotypes : 117491b,c,e,g-i; unfigured hypotypes: 117491A4,4d,f.

Horizon and locality.—Curdsville formation in Kentucky.

Basal Martinsburg formation (=Curdsville): Along the Cumberland front
and elsewhere in Virginia and Tennessee.

Discussion.—The differences between this species and S. punctostriata are
discussed on page 792. The two species are sufficiently close to be ecads of a
single species, but larger collections than those available in this study will be
necessary to demonstrate the point.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 781

SOWERBYELLA EXIMIA Cooper, new species
Plate 204, C, figures 13-33; plate 205, B, figures 7, 8

Large for the genus, length two-thirds the width; cardinal extremities varying
from slightly alate to slightly obtuse; sides gently rounded, slightly oblique to
nearly straight; anterior margin ranging from broadly rounded to somewhat
truncated. Ornamentation of the same type as that of S. punctostriata, con-
sisting of costellae of unequal size, from I to 5 fine costellae separated by stronger
ones; about 30 costellae in 5 mm. at the front margin. Costellae beaded. Pos-
terior margin of both valves with oblique wrinkles.

Pedicle valve having an uneven lateral profile, the greatest convexity located
just anterior to the umbo, anterior profile broadly triangular, the median crest
somewhat narrowly rounded but the sides long and flat and dipping only mod-
erately steeply. Umbonal region gently inflated; fold low, indistinct, extending
from umbo to anterior margin but not clear in all specimens. Median region
gently inflated. Interior with oval diductor patches and short median septum.
Inner surface strongly papillose. No strong vascula media extending from diduc-
tor scars.

Brachial valve moderately concave, most concave in the umbonal and median
regions, the concavity forming a sort of sulcus; flanks gently concave toward
the median region but flattening laterally and anteriorly. Posterolateral extremi-
ties flattened. Interior with large muscle field but with septa low and delicate,
reaching a crest at about the middle of the valve. Inner surface papillose particu-
larly the broad, gently sloping area anterior to the septa.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Fl olotype') /scicic/ aks! =e 10.0 0.4 16.5 16.5 1.8 3.1
Paratype (117492b).. 11.7 10.8 19.0 18.8 2.1 3.9
* (117492c).. 11.5 10.6 16.7 16.0 2.4 3.5
: (117492h).. 89 8.2 14.3 ? 14.6 1.7 3.0
ef (117492j) .. 10.7 9.6 16.0 16.3 2.6 3.9
. (117492k).. 8.4 7.9 13.4 14.6 2.2 35

Types.—Holotype: 117492a; figured paratypes: 117492c,d,f,h,j,k,n,p; un-
figured paratypes: 117492b,e,g,i,l,m,0,q,r.

Horizon and locality—Oranda formation in Virginia: Just west of junction
of Virginia County Highways 617=91!0 and 777, on 777, 4 mile north of Green
Mount Church, Broadway (15’) Quadrangle.

Martinsburg formation (part with Brongniartella=Salona) in Virginia: On
Virginia County Highway 617=910, 0.15 miles north of Green Mount Church,
Broadway (15’) Quadrangle.

Discussion.—Large size, beaded costellae, and poorly differentiated costellae
are features of this species. The shell is not so robust as S. curdsvillensis nor
are its interiors as much thickened as those of the Kentucky species. Sowerbyella
eximia does not attain as large a size as S. punctosiriata (Mathers), and its cos-

782 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

tellae are not arranged in groups of several fine ones alternating with coarser
ones as in the Wolfe Island species.

SOWERBYELLA INDISTINCTA Cooper, new species
Plate 202, D, figures 24-26

The specimens on which this species is based are smaller than Sowerbyella
compacta from the Benbolt formation in Virginia and Tennessee and have nearly
the same shape but differ in ornamentation and size. These two species are
very close, but despite their similarity constant differences between the two
occur that are sufficient to distinguish them. In external form the Oklahoma
shell has more oblique or sloping lateral margins and somewhat more acute
cardinal extremities. The Appalachian species attains a greater size. The con-
tours of the two species differ slightly, the Oklahoma form having in general a
somewhat more concave brachial valve. In ornamentation the eastern species
has less numerous costellae, about 120 as compared with about 140 in the Okla-
homa form. Furthermore, no crescentic spines were observed on the latter,
although concentric fila are easy to see.

Inside the valves the Oklahoma shell seems to be less thickened in both valves
when compared with specimens of similar size from the Appalachians. The
brachial valve of S. compacta has a much wider and more greatly thickened
periphery.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype (pedicle valve) ........... 6.7 ? 9.4 11.4 ?
Paratype ( “ sage LIGAOSD) 5. «wag gee ‘3 10.1 10.4 ?
oy es Siw’ It74Osa)N.. 6H ? 10.0 11.7 (4
‘ (Oa% caw gegaggae) 2. 7G ? 10.9 II.0 ?
4 (brachial valve 117493c)... ? 6.7 10.3 12.0 r
+4 (a Raho ok BAO D5 wor AP 6.4 9.8 ? ?

Types.—Holotype: 117493a; figured paratypes: 117493b,c, unfigured para-
types: 117493a’, a”, a”.

Horizon and locality—Bromide formation (Mountain Lake member) in Car-
ter County, Okla.: About the middle of sec. 33, T. 2 S., R. 2 E., 2 miles north-
east of Springer; SE1 sec. 32, T. 2 S., R. 2 E., 3 miles north-northeast of
Springer.

SOWERBYELLA LEBANONENSIS Bassler
Plate 201, B, figures 14-25
Sowerbyella lebanonensis BASSLER, Tennessee Div. Geol., Bull. 38, p. 192, pl. 5, figs. 7, 8,
1932 (nomen nudum) ; Journ. Washington Acad. Sci., vol. 25, No. 9, p. 406, 1935.

About medium size for the genus, wider than long with the length slightly
less than two-thirds the width. Outline subrectangular; lateral margins nearly
straight, sloping gently toward the middle; anterior margin very broadly rounded
to truncate or, in some specimens, slightly emarginate. Cardinal extremities

PART = CHAZYAN AND RELATED BRACHIOPODS—COOPER 783

forming an acute angle, produced slightly into small points or ears. Surface
marked by costellae of unequal size, the larger ones separated by I to 5 of the
finer ones. In addition to the radial markings the surface is covered by very
fine concentric fila and up to 7 short, oblique wrinkles along the posterior mar-
gins on each side of the hinge.

Pedicle valve with moderate curvature in lateral profile and forming a broad,
gentle arch in anterior profile. The beak is inconspicuous and only very slightly
produced beyond the posterior margin. Umbo low and broad, not easily dis-
tinguished from body of shell. Midregion and flanks somewhat swollen; slopes
to cardinal extremities steep. Anterior slope steep. Interarea not much longer
than that of the brachial valve, short, apsacline. Pseudodeltidium nearly obsolete.

Brachial valve moderately concave with the concavity greatest at about the
middle ; flanks gently concave and anterolateral areas somewhat flattened. Cardi-
nal extremities very slightly deflected. Interarea hypercline, nearly as long as
the interarea of the pedicle valve.

Interior: Pedicle valve with delthyrial cavity wide, partially filled by callus
deposit ; median ridge very thin in the young, well thickened in the adult, ex-
tending about one-third the length of the valve. Ridges bounding outside mar-
gin of diductor-adjustor field short and stout; diductor-adjustor field wide and
long extending to the middle of the valve. Shell thickened and papillose just
inside the anterolateral margins.

Brachial valve interior with median ridge and lateral septa low; shell not
greatly thickened in the young but strongly thickened in old shells forming a
strong subperipheral border on the sides and toward the front and a steep an-
terior slope. In old shells medium septum becoming obsolete and lateral septa
greatly thickened.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness Height
MECtOtypen.\s laches stee < eers 73 ? II.5 12.4 ? 1.5?
Hypotype (117497a)... 6.8 ? 10.1 11.2 fe ?
CEI74075) wsteu..2 7.0 12.1 13.2 ? Ts
‘ (1274070) ac ak 7.9 LAg 122 ? ?
: (117494a)... 9.1 8.2 14.4 15.3 2.2 3.2

Types—Lectotype: 80487a, paratypes: 80487b-d; figured hypotypes:
117494a-c, 117495a, 117496a, 117497c; measured hypotypes: 1174972,b.

Horizon and locality.—Lebanon formation in Tennessee: At Shelbyville, Bed-
ford County; Columbia, Maury County; near Prospect, Giles County; near
Bradyville, Cannon County; LaVergne, Rutherford County. Cut on U. S.
Highway 241, 2.1 miles north of Bedford County line; U. S. Highway 70S,
14 miles east of Brinkley School, east of Murfreesboro; near Readyville; U. S.
Highway 70S, 1.65 miles west of Cripple Creek, 1.5 miles west of Kittrell;
Rutherford County. On Tennessee Highway 16, 1 mile south of Rutherford
County line.

Discussion.—This species occurs in great abundance in the lower part of the

784 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Lebanon limestone of the central basin of Tennessee. It is characterized by its
transversely subrectangular outline, the well-differentiated costellae, and the mod-
erately thickened interiors.

This species name first appeared in Dr. Bassler’s description of the Stra-
tigraphy of the Central Basin of Tennessee. In that publication the name proved
to be a nomen nudum because the illustrations were unaccompanied by a de-
scription. Three years later a short characterization was published, but this
failed to indicate a type specimen. In the original publication two specimens were
figured, and these were again referred to in the later characterization. These
two specimens are thus the cotypes. It seems best here to select the pedicle
valve (fig. 8) U.S.N.M. 80487a. This is a most unfortunate specimen to repre-
sent the species because it is crushed and has an unusual development of wrinkles
on the posterior margin. It is better, however, than the other alternative which
is a brachial interior.

Bassler’s characterization stressed the ornamentation and the fact that the
septa of the brachial valve almost meet the anterior margin. This seems to be
true in a few specimens, but generally the brachial plates terminate in a crest
near the valve middle as they do in all other species.

Sowerbyella lebanonensis, because of its considerable width, should not easily
be confused with other Sowerbyellas described in this report. It is in that re-
spect unlike S. compacta and S. socialis, which might be confused with it. The
latter, moreover, is much more coarsely ornamented, and in the former the cos-
tellae are not arranged in sectors of fine and large ones as in S. lebanonensis.

SOWERBYELLA MEDIOPLICATA Cooper, new species
Plate 204, A, figures 1-5

Small, semielliptical in outline ; hinge forming the widest part, auriculate ; sides
oblique; anterior margin broadly rounded; costellae subequal, about 4 to the
millimeter at the front margin.

Pedicle valve moderately convex in lateral profile with the maximum con-
vexity at about the middle; anterior profile broadly convex with the median
region narrowly humped and the flanks depressed below it; lateral slopes mod-
erately steep. Umbonal and median regions narrowly swollen to form a marked
median fold which forms a wave in the commissure; flanks moderately swollen.

Brachial valve with a prominent median sulcus extending from umbo to an-
terior margin; flanks fairly deeply concave but posterolateral extremities some-
what flattened. Interior with slender median plates; anteromedian region mod-
erately thickened.

Measurements in mm.—Holotype, length 4.8, brachial length 4.3, midwidth
7.4, hinge width 8.7, thickness 1.3, height 1.8.

Types.—Holotype: 117498.

Horizon and locality—Upper Lincolnshire formation in Virginia: Along
Tumbling Run, 14 miles southwest of Strasburg, Strasburg (15’) Quadrangle.

Discussion.—This species is characterized by small size, fairly strong but

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 785

poorly differentiated costellae, and the presence of a strong plica or fold on the
pedicle valve. This species is smaller than S. silicica which is not so strongly
folded. It is suggestive of S. varicostellata but is also smaller than that species,
more strongly concave, more strongly folded in the median part of the pedicle
valve, and has stronger costellae.

SOWERBYELLA MERRIAMI Cooper, new species
Plate 269, D, figures 18-22

Shell of about medium size for the genus, wider than long and with the hinge
forming the greatest width; sides slightly rounded, sloping medially ; anterior
margin strongly rounded; anterior commissure rectimarginate. Surface costel-
late, costellae of unequal size, 7 to 9 of the strongest ones in 5 mm. at the front
margin, each of the stronger costellae separating I to 5 of the finer ones. Pos-
terior margins with numerous irregular, oblique wrinkles.

Pedicle valve gently convex in lateral profile, with the greatest convexity in
the posterior third and with the anterior two-thirds flattened. Anterior profile
subcarinate. Umbo narrowly swollen; umbonal slopes short and gentle, melting
into the flattened flanks and medial portion. Interarea strongly apsacline and
moderately long. Pseudodeltidium small.

Brachial valve nearly flat except in the umbonal region which is deeply con-
cave, the concavity extending along the posterior margin and dying out on the
flanks and median region, lateral and anterior regions nearly flat.

Interior unknown.

Measurements in mm.—Holotype, length 11.6, length of brachial valve 11.0,
midwidth 17.3, hinge width 18.9, thickness 2.1.

Types.—Holotype: 124234a; unfigured paratypes: 124234b-d.

Horizon and locahity—Dark shale under the Eureka quartzite in Nevada:
Under two knobs of Eureka quartzite, north side of canyon, 3.1 miles N. 32° E.
of the Blair (Segura) Ranch, Antelope Mountains, Roberts Mountains (1°)
Quadrangle.

Discussion.—This species can be recognized by its fairly large size, wide hinge,
strong ornamentation, and flattened form. It is suggestive of S. eximia from
contemporaneous rocks in Virginia but is more strongly ornamented and flatter
in profile. Sowerbyella monilifera resembles the Nevada species but is usually
smaller, less extended along the hinge, and has finer ornamentation.

SOWERBYELLA MONILIFERA Cooper, new species
Plate 199, A, figures 1-8; plate 206, E, figures 16-28

Shell large, subrectangular to subelliptical in outline, wider than long, with
the length about two-thirds the width; cardinal extremities angular to auriculate.
Sides gently rounded, moderately oblique; anterior margin broadly rounded;
costellae of several sizes but with a prominent strong set in a field of fine ones;
8 of the stronger costellae occupy 5 mm. at the front margin; larger costellae
separated by 1 to 6 of the fine costellae, which are beaded.

786 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve unevenly convex in lateral profile with the maximum convexity
just anterior to the umbo; anterior profile with the median region narrowly ele-
vated to form a moderately elevated hump with the sides concave and descending
moderately to the margins; beak small; umbo somewhat narrowly swollen and
passing into the moderately inflated median region; umbonal slopes to posterior
margin short and moderately steep. Anterior slope long and gentle; posterior
slope short and steep. Interarea moderately long, strongly apsacline; pseudo-
deltidium small.

Brachial valve most concave just anterior to the umbo which is also concave;
lateral areas gently concave and posterolateral extremities somewhat flattened.

Pedicle interior with elongate diductor scars diverging at an angle of about
55°; median ridge low, anterior forks of median ridge low; pallial trunks not
strongly developed. Brachial valve with median ridges low and closely spaced ;
adductor callosity elongate, narrowly oval; marginal thickening not strong.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height

IHOLOLY DE: ponisrae see sees 9.6 9.2 T52 16.9 1.8 2.5
Paratype (117499a).. 9.1 8.7 13.2 15.1 £7 2.2
a (117500a).. 11.9 11.2 17.0 19.4 ? e
i“ (117500c).. 9.8 0.5 13.5 15.5 2.1 2.6
“ (117500d).. 11.4 II.0 15.5 16.1 ? 2.3 3.2
- (117500e).. 9.2 8.9 14.1 16.2 1.9 2.8
“ (117500f).. 9.6 9.0 15.1 16.5 1.3 2.3
4 (1175001) .. ? 8.8 13.8 14.8 ? ?
5 (117500-1) . ? 8.9 12.0 12:3 ? ?
. (117500m) . 11.2 10.5 16.6 17.6 2.8 3.6

Types —Holotype: 117500b; figured paratypes: 117499a,b, 117500a,c,g,i; un-
figured paratypes: 117500d-f,h,j-m.

Horizon and locality—Decorah formation (Ion member) in Goodhue County,
Minn.: about 1 mile east of U. S. Highway 52, on the south side of Cannon
Falls; Wagner Hill, on U. S. Highway 52, 5 miles south of Cannon Falls;
Kenyon; Minneapolis; and in Fillmore County: On U. S. Highway 52, 1 mile
south of Fountain.

Same formation in Iowa: Along the Dugway, 4 mile west of Decorah, Winne-
shiek County.

Same formation in Wisconsin: From a cut on Wisconsin Highway Io, 4 mile
west of Ellsworth, Lancaster (30’) Quadrangle.

Discussion.—Its large size and its well-differentiated and strongly beaded cos-
tellae make this species comparable with S. punctostriata and similar species.
The Minnesota species differs from S. punctostriata in its lesser width and more
compact form. It is a much less robust form than S. curdsvillensis, and its in-
teriors are not so strongly thickened. Sowerbyella eximia is somewhat differ-
ently proportioned and has a completely different ornamentation.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 787

SOWERBYELLA NASUTA Cooper, new species
Plate 199, C, figures 18-34; plate 215, A, figures 1-4

Shell small, subquadrate, wider than long; sides nearly straight ; cardinal ex-
tremities nearly a right angle; ears small; anterior margin subnasute. Finely
costellate, with about 5 or 6 costellae in 1 mm. at the front margin.

Pedicle valve fairly strongly and evenly convex in lateral profile with the me-
dian region being the most convex part ; anterior profile broadly convex ; umbonal
region narrowly convex, often subcarinate medianly, the convexity continued to
the front margin as a moderately strong, narrow median fold; flanks gently in-
flated, depressed somewhat below the median fold and with moderately steep
slopes to the margins. Interarea moderately long, strongly apsacline. Interior
with short, rounded, deeply impressed diductor scars with strong, branched
pallial sinuses diverging from their anterior ends. Median ridge low.

Brachial valve gently concave and marked by a distinct narrow, shallow sul-
cus extending from beak to anterior margin; flanks bounding sulcus gently con-
cave to flattened; posterolateral extremities flattened. Interior with 2 closely
spaced septa strongly elevated near the middle of the valve; slope anterior to
anterior ends of septa steep, strongly papillose. Sides depressed, papillose, and
moderately thickened inside the margin.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
| 0) 00) 5,0 en 8.1 7.4 9.9 10.1 253 2.9
Paratype (117503a)..... 7.0 6.2 8.9 9.2 Ait 2.5
F CIT7503C)iencr 7.0 6.3 9.0 9.5 2.1 28
Fr (rT75024a)" 7.2 6.4 5.9 8.3 9.7 1.9 2.3

Types.—Holotype: 117503b; figured paratypes: 117502a-c, 117503a,c-h;
figured specimen: 117501.

Horizon and locality—Chatham Hill formation in Virginia: On the north
slope of Walker Mountain, 2 miles south-southwest of Chatham Hill, Chatham
Hill (T.V.A. 218-NE) Quadrangle.

Ward Cove formation (Nidulites bed) in Virginia: Thompson Valley, south-
west of Tazewell, Pounding Mill (15’) Quadrangle.

Ward Cove formation (just above Nidulites) in Virginia: North of U. S.
Highway 19, 4 mile west of Pounding Mill, Pounding Mill (15’) Quadrangle.

Discussion.—This little species is characterized by the prominent median fold
on the pedicle valve. This fold is narrow and extends from the beak to the an-
terior margin and may cause the margin to become nasute. A number of species
have developed a median fold similar to this one, but it is not so marked in any
other species as in this one and S. subcarinata. Sowerbyella nasuta differs
from S. carinata in size and proportions, the former being more quadrate and
having a length/width index of about 0.78 whereas that of S. subcarinata aver-
ages about 0.70.

788 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

SOWERBYELLA NEGRITUS (Willard)
Plate 197, A, figures I-10

Plectambonites negritus WiLtLarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 278, pl. 3, fig. 13, 1928.
Sowerbyella sp. Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 72, pl. 81, figs. 21, 22, 1942.

Shell of about medium size for the genus, wider than long with the length
about two-thirds the width; hinge forming the greatest width and about twice
the length. Lateral margins slightly curved; anterior margin broadly rounded.
Surface marked by costellae of unequal size. Five to seven of the stronger cos-
tellae may be counted on each side of a still stronger median costella. The
stronger costellae define low plications that wrinkle the front margin. Between
the stronger costellae 2 to 8 of the finer radii occur. About 13 costellae may be
counted in 2 mm. at the front of a large valve. In addition to the costellae 4
oblique wrinkles are present along the hinge on each side of the beak.

Pedicle valve evenly and moderately convex in lateral profile and with the
most convex part of the shell at the middle. Anterior profile with sides rising
gradually to the highest part in the middle of the valve which is humped into a
low fold. Beak inconspicuous and only slightly produced posterior to the pos-
terior margin. Beak and umbo produced into a low fold broadening anteriorly
to occupy about one-quarter of the width. Region about cardinal extremities
flattened, rising gradually to the base of the fold. Sides of fold moderately steep.
Interarea short, nearly flat, apsacline.

Brachial valve strongly concave with the greatest concavity in the median
region. Sulcus narrow and extending to the anterior margin where it indents
the commissure toward the pedicle valve. Concavity decreasing laterally. Cardi-
nal extremities sulcate, deflected toward the pedicle valve. Anterolateral areas
not strongly incurved.

Interiors: Not known in detail. Structures of brachial valve appear to be
characteristic of Sowerbyella.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Hypotype (117504a)... 6.1 5.3 9.7 II.9 1.3 1.8
ff (117504c)... 5.8 ? 8.8 10.8 ‘4 2.0?
ss (117506a)... 7.8 ? 13.0 15.0 ? ?

Types.—Holotype: M.C.Z. 8615; figured hypotypes: 117504a,c, 117505d,
117506a,b.

Horizon and locality—Botetourt formation in Virginia: At junction of Vir-
ginia Highways 311 and 114, 4 mile southwest of Catawba, 11 miles north of
Salem, Salem (15’) Quadrangle; 14 miles southeast of Harrisonburg, Harrison-
burg (15’) Quadrangle; on Virginia Highway 114, 2.3 miles west of Mont-
gomery-Roanoke County line, 12 miles northeast of Blacksburg.

Effna formation in Virginia: At Porterfield Quarry, 5 miles east of Saltville,
Maccrady (T.V.A. 218-NW) Quadrangle; McNutt Quarry, 12 miles southwest
of Bland, Burkes Garden (15’) Quadrangle. .

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 789

Ward Cove formation in Virginia: 0.4 mile northeast of Jeff Gillespie’s,
Thompson Valley, west-southwest of Tazewell, Pounding Mill (15’) Quad-
rangle.

Lower Chatham Hill formation in Virginia: On the Grayson Farm, 4 miles
southwest of Bland; 6 miles southwest of Bland; Bland County.

Whitesburg formation in Tennessee: 14 miles northeast of Bulls Gap, Bulls
Gap (T.V.A. 171-SE) Quadrangle.

Discussion.—Sowerbyella negritus is best characterized by its ornamentation,
the depth of its valves, and the pointed cardinal extremities. The ornamentation
consists of strong costellae separated by 2 to 8 finer costellae, the higher num-
bers of finer costellae predominating. The shell is also well wrinkled along the
posterior margin. In addition to these features a crude, obscure plication ap-
pears in some of the shells, particularly the median part of the pedicle valve which
is often strongly folded.

Few species have been described that can be compared to this one. It is close
to S. perplexa, but that species is generally more convex, does not have a promi-
nent median fold, and the strong costellae are separated by a smaller number
of the fine radii.

SOWERBYELLA PARVA Cooper, new species

Plate 202, B, figures 9-15

Shell small for the genus, wider than long, semielliptical in outline; sides
nearly straight to gently convex ; anterior margin rounded; widest near the mid-
dle in the adult; cardinal extremities nearly a right angle, rarely auriculate;
finely costellate, costellae fairly even in size but somewhat differentiated into
larger and smaller ones at the front margin: 6 to 7 costellae in I mm. at the front
margin.

Pedicle valve moderately convex in lateral profile; anterior profile rising to a
low crest medially and with long, flat, moderately dipping slopes. Umbo nar-
rowly swollen; median fold absent or obscure; flanks gently inflated; interarea
strongly apsacline.

Brachial valve with a poorly defined concave sulcus extending from the con-
cave umbo to the front margin ; center of valve most deeply concave part; flanks
gently concave, lateral and posterolateral regions flattened.

Pedicle interior with short but strong median septum dividing subflabellate
diductor fields; pallial trunks moderately developed. Brachial valve moderately
thickened ; septa moderately elevated at the middle of the valve; anterior slope
not strongly thickened.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Plolotype? te. fees sete ces 6.5 6.1 9.0 8.7 1.4 1.9
Paratype (117507b) ... 7.0 6.6 0.4 8.9 1.7 2.2

Types——Holotype: 117507a; figured paratypes: 117507b-d.
Horizon and locality—Ward Cove formation in Virginia: In small cemetery

700 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

about 3 mile north of Rye Cove; 1 mile northwest of Rye Cove, Clinchport
(T.V.A. 188-NW) Quadrangle.

Discussion.—This species is small and marked by fine costellae; it resembles
S. compacta in form but is never so large, and is not so deep as the Benbolt
species. Sowerbyella indistincta is like this species in size, but it has acute cardi-
nal extremities in the adult whereas in S. parva the cardinal extremities are ob-
tuse. Furthermore, the brachial valve of the Ward Cove species is more shallow
than that of the Oklahoma species.

SOWERBYELLA PERPLEXA Cooper, new species
Plate 196, F, figures 30-44

Shell of about medium size for the genus ; semielliptical in outline ; wider than
long with the hinge forming the widest part; cardinal extremities auriculate ;
sides oblique ; anterior margin broadly rounded; 2 large costellae in 1 mm. at the
front margin; 3 to 5 fine costellae between the larger ones. Obscure oblique
wrinkles on the posterior margins.

Pedicle valve fairly evenly and moderately convex in lateral profile; anterior
profile with median region rounded, not strongly elevated and with long gentle
slopes. Valve swollen in the middle; umbo moderately inflated.

Brachial valve most strongly concave just anterior to the umbo; concavity
lessening anteriorly and laterally; posterolateral regions gently concave.

Pedicle interior with narrow, deep, widely divergent diductor scars; median
ridge short; brachial interior with delicate septa and often having the median
septum unusually well developed.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
THOLOty pe eieie es « aieiciiens tater 6.2 5.4 9.7 II.0 13 2.2
Paratype (117508c)... 5.2 4.7 7.8 9.1 1.0 1.6
S Crrz7gegk)~.. ‘6.2 5.6 8.4 0.7 1.3 er
i (117508E) .'.. P 8.0 12.5 12.5 ? ?

Types.—Holotype: 117509a; figured paratypes: 117508b-g,i; unfigured para-
types: 117508a,h,j-l, 117509b.

Horizon and locality—Chatham Hill formation in Virginia: On north slope
Walker Mountain, 1.2 miles S. 31° E. of Sharon Springs, Burkes Garden (15’)
Quadrangle.

Discussion —Sowerbyella perplexa has its fine costellae blocked out in definite
bands by strong costellae, and the brachial valve is fairly deep. The species is
most like S. negritus but differs in not having the costellae arranged in as broad
bands as those of S. negritus and in not having a narrowly convex median region
on the pedicle valve and a somewhat sulcate brachial valve. The Chatham Hill
species also lacks the strong suggestion of plication on the pedicle valve of
S. negritus.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 791

SOWERBYELLA PLICATIFERA Cooper, new species
Plate 203, A, figures 1-15

Shell of about the usual size for the genus, wider than long and with the width
at the hinge nearly twice the length. Cardinal extremities acute to mucronate.
Lateral margins oblique and straight to oblique and somewhat rounded. An-
terior margin broadly rounded to nasute. Anterior commissure often wrinkled
by 3 more or less strong plications, 1 on the pedicle valve and 2 on the brachial
valve. Surface multicostellate ; costellae crowded, narrowly rounded, with inter-
spaces narrower to slightly wider than the width of the costellae, varying from
nearly equal in size to well differentiated in size with as many as 3 fine costellae
separating the larger ones, about 120 to 160 in number. At the front margin 5
to 7 costellae occupy a space of 1 mm. Interspaces occupied by fine, elevated con-
centric fila. Costellae ornamented by small crescent-shaped spines, about 6 to
the millimeter, giving them a beaded effect.

Pedicle valve forming a low arch in anterior profile with a narrowly rounded
crest and sides sloping gently to the margins. In lateral profile the curvature is
moderate and the greatest curvature is slightly posterior to the middle. Beak
inconspicuous; umbo narrowly elevated and extended forward to the front
margin as a low narrow fold outlined by a shallow depression on each side.
Flanks narrowly but often obscurely folded by a low plica that meets the front
margin at the anterolateral extremities. Slopes to cardinal extremities concave
but gentle. Interarea short, slightly curved and apsacline in position.

Brachial valve with most concave portion near the middle and with the con-
cavity extending to the front margin as a narrow sulcus. Sulcus bounded by
low, narrowly rounded plications that extend to about the middle of the valve.
Outside each plica a shallow sulcus may occur, but often, especially in younger
specimens, the shell is gently concave to the cardinal extremities where it is
somewhat flattened. Cardinal extremities slightly deflected toward the pedicle
valve. Interarea short, hypercline.

Interior: Not known beyond the fact that the brachial valve possesses typical
Sowerbyella septa.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness Height
Holotype). 2202.02.02 8.90 8.2 13.6 15.0 1.8 28
Paratype (117512a).. 8.6 8.0 12.5 12.9 1.4 2.6
4 (iP7S128) 24178 7.4 12.0 14.5 1.9 2.6
“s (11751Ib).. 7.8 7.6 11.9 13.8 ie Ze

Types.—Holotype: 117512b; figured paratypes: 117511a, 117512a; unfigured
paratypes: 117510, I17511b,c.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: West of Nebo, Murray County; NW} sec. 25, T. 2 S., R. 1 E., + mile
west of U. S. Highway 77, Carter County.

Discussion.—This species is characterized by strongly beaded costellae, deep
brachial valve, acute cardinal extremities, and the presence of fairly strong folds,

792 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the median one always present but others on the flanks usually visible. Sower-
byella plicatifera is most like S. socialis and S. variabilis. It differs from the
first in not being so robust, in being deeper, particularly along the posterior
margin of the brachial valve, in being more finely costellate, and in having more
prominent plicae. Sowerbyella plicatifera differs from S. variabilis in its stronger
costellae, the prominent folding of the pedicle valve, and the less deep brachial
valve.
SOWERBYELLA PUNCTOSTRIATA (Mather)

Plate 205, C, figures 9-25; plate 206, D, figures 14, 15

Plectambonites punctostriatus MATHER, Ottawa Nat., vol. 31, p. 38, pl. 1, figs. 15-17, 1917.

This species is widely identified in the lower part of the Trenton, particularly
in New York and Ontario. The species is characterized by its large size and
beaded ornamentation which gives the appearance of a pitted or punctate sur-
face. It is most like S. curdsvillensis Foerste which is widely distributed in the
Southern Appalachians and parts of the upper Mississippi Valley. Sowerbyella
punctostriata is distinguished from S. curdsvillensis as follows: 1, lesser con-
vexity and generally thinner valves; 2, less deeply concave brachial valve;
3, greater development of the oblique wrinkles along the posterior margins;
4, fairly late development of thickened subperipheral ridge in old adults; 5, lesser
thickening of all internal structures; 6, greater tendency to auriculate cardinal
extremities.

Specimens in the National Museum indicate that this species is variable. Per-
haps when its stratigraphic range has been more accurately worked out, some
splits may be made from it. As indicated by topotypes the species is fairly thin
shelled, only moderately convex, and the interior is scarcely thickened to a nota-
ble degree. The amount of thickening of the internal structures and the develop-
ment of a subperipheral rim were given by Mather as points of distinction be-
tween S. punctostriata and S. curdsvillensis. Specimens referrable to the former
species have been seen which have a prominent subperipheral rim and pro-
nounced internal features. On the other hand, specimens referrable to the Ken-
tucky species occur which do not have the strongly emphasized interiors. The
degree of development of these features may be a matter of environment, the
quiet-water limestone specimens having the delicate shell while the dwellers of
sandy bottoms of the basal Martinsburg in the Southern Appalachians with its
more turbulent water having the stronger shells. It is further possible that large
suites of specimens will indicate that S. punctostriata and S. curdsvillensis are
actually one species.

Types.—Figured hypotypes: 117513a,b, 117514a,b, 117515a,b; figured topo-
type: 117516.

Horizon and locality—Rockland formation in New York and Ontario: Wolfe
Island, Lake Ontario.

Decorah formation (Guttenberg member) in Wisconsin, Iowa, Minnesota,
and Missouri.

Barnhart formation in Missouri: Koch Valley School, on U. S. Highway 61,
NE. corner SW4SW3 sec. 6, T. 41 N., R. 6 E., 2 miles south of Barnhart,

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 793

Kimmswick (15’) Quadrangle; old road 1 mile northwest of Chicago Summer
School Camp, NW4SW3 sec. 32, T. 37 N., R. 9 E., Weingarten (15’) Quad-
rangle.
SOWERBYELLA SILICICA Cooper, new species
Plate 196, D, figures 20-26
Sowerbyella sp, Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 42, pl. 73, figs. 40, 41, 1942.

Width of shell at hinge slightly less than twice the length; cardinal extremities
acute, drawn into small ears; lateral extremities indented just anterior to the
ears ; anterolateral margin moderately rounded ; anterior margin broadly rounded.
surface marked by costellae of unequal size ; about 20 to 30 of the larger ones are
separated by 2 to 4 of the smaller costellae. The median stronger costella of the
pedicle valve is often the strongest and most prominent of all.

Pedicle valve gently convex in lateral profile; unevenly convex in anterior
profile with the median region elevated and the lateral areas or flanks descend-
ing gently to the lateral margins. Beak low, inconspicuous, protruding only
slightly posterior to the posterior margin. Umbo narrowly elevated and extend-
ing anteriorly into the narrow median fold. In the anterior portion of the valve
and on each side of the fold short sulci often exaggerate the height of the fold.
Flanks nearly flat or very gently convex in profile. Interarea slightly curved,
nearly orthocline to gently anacline in position.

Brachial valve generally moderately to deeply concave, with the greatest con-
cavity slightly anterior to the middle. Umbo concave; sulcus widening from the
umbo to the front margin where it is about one-fourth the width at the hinge.
Width of sulcus dependent on production of feeble to moderately strong plicae
on each side ; the stronger the lateral plicae the narrower the fold. Flanks bound-
ing fold nearly flat to moderately concave. Brachial ears faintly concave to flat.
Interarea strongly hypercline.

Interior: Pseudodeltidium reduced; median adductor ridge strong, equal in
length to about one-fourth the length of the valve; ridges bounding anterior
margin of diductor scars diverging at an angle slightly less than a right angle.

Brachial valve with lateral septa most elevated at a point slightly anterior to
the middle; median septum nearly obsolete. Muscle area slightly thickened and
most elevated at the point where the septa end.

Measurements in mm.— peed Hinge
Length length Midwidth width Thickness Height

TROLOEYV PO isis wiaisge 9 m:a'slars 6.1 5.6 8.8 II.0 i3 2.2
Paratype (117517b)... 68 6.1 9.5 II.o? 1.4 25
ss (98213d).... 4.9 4.7 7.0 78 1.0 123

T'ypes—Holotype: 1175174; figured paratype: 117517b; unfigured paratypes:
98213a-c, 123457; measured paratype: 982134.

Horizon and locality—From the upper part of the Arline formation in Vir-
ginia: At entrance to Porterfield Quarry, 5 miles east of Saltville, Maccrady
(T.V.A. 218-NW) Quadrangle.

Discussion—This is a small species characterized by costellae prominently
grouped into strong ones alternating with groups of finer ones. In this respect
it is like S. negritus but never attains the large size of that species. It is also

704 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

not so strongly alate, and the bands of fine costellae are much narrower. The
species is suggestive of S. varicostellata but is a larger species.

SOWERBYELLA SILICICA NANA Cooper, new subspecies
Plate 196, C, figures 15-19
Sowerbyella sp. Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 42, pl. 73, fig. 38, 1942.

Shell small, wider than long with the width about one-third greater than the
length; hinge forming widest portion; cardinal extremities forming an acute
angle; slightly auriculate. Lateral margins slightly indented just anterior to the
cardinal extremity and nearly straight or slightly curved before joining the
narrowly rounded anterior margin. In old specimens the anterior commissure
is sulcate and the anterior margin may be slightly produced by the sulcus. Sur-
face marked by costellae of unequal size, about 28 of the larger costellae sepa-
rated by 2 to 4 of the finer ones.

Pedicle valve having a gently convex lateral profile but with the anterior pro-
file strongly arched at the middle and with sides flattened. Beak low, inconspicu-
ous, scarcely protruding posterior to the posterior margin. Umbonal region nar-
rowly swollen and produced forward to join with a conspicuous, rounded, but
low fold. Lateral slopes flattened, moderately steep. On each side of the fold a
low plica is often visible on the lateral slope and extending to the anterolateral
extremity. Interarea nearly flat, moderately to strongly apsacline. Pseudodel-
tidium short, narrow.

Brachial valve unevenly concave with the greatest concavity located along the
median line where the valve is deeply sulcate. Umbo concave. Flanks of shell
bounding sulcus only moderately concave and with 2 indefinite but perceptible
plicae corresponding to the depressed areas of the ventral flanks bounding
the fold. Interarea anacline.

Interior: Nothing known beyond the presence of the 2 diverging septa.

Measurements in mm.— Buen Hinge
Length length Midwidth width Thickness Height
HIGloty Be Voss sis sec tle» we 6.4 6.1 8.2 8.0 1.4 21
Paratype (117518a)..... 6.6 5.9 8.3 9.4 1.8 2.3
* (GiB) hoaor 6.7 5.9 8.4 9.0 1.4 2.6
oe (2175186) ence 6.2 5.3 8.6 8.7? Lz 2.2

Types.—Holotype: 98229a; unfigured paratypes: 98229b, 117518a-c.

Horizon and locality.—Arline formation in Virginia: At entrance to Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This subspecies differs from S. silicica in its somewhat smaller
size and in the nearly rectangular cardinal extremities.

SOWERBYELLA SOCIALIS Cooper, new species
Plate 108, B, figures 23-44; plate 205, A, figures 1-6
Sowerbyella sp. Butrs, Virginia Geol. Surv. Bull. 52, pt. 2, p. 93, pl. 90, figs. 1-16, 1942.

Shell semielliptical, length about two-thirds the width at the middle; hinge
forming widest part ; cardinal extremities acute, often drawn out into small ears;

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 795

lateral margins generally straight in outline and sloping moderately toward the
middle. Anterior margin usually broadly rounded, occasionally slightly nasute
when the fold is well developed. Posterior margin nearly straight. Surface multi-
costellate ; costellae appearing in 3 generations. Second and first generation cos-
tellae of about same size at front of valve; 1 to 2 of the finer costellae of the second
and third generation alternate with the coarser ones. At the front margin of a
fully adult valve about 120 to 130 costellae of all sizes may be counted, about 5 in
I mm. at the front margin near the center. Between the costellae the shell is
marked by fine, crowded concentric fila; in very well preserved specimens the
costellae bear short imbricating spines. A few wrinkles along the posterior mar-
gin occasionally seen.

Pedicle valve moderately but unevenly convex in lateral profile; anterior pro-
file with the greatest convexity in the middle but not greatly elevated and with
the flanks sloping gently to the margins. Beak inconspicuous, protruding very
slightly beyond the posterior margin. Umbo narrow, slightly swollen, extended
forward as a low and narrow fold nearly to the front margin. Flanks bounding
fold full in anterolateral regions; slopes to cardinal extremities moderate. A
tendency to form an obscure plication along the middle of each flank has been
observed. Interarea curved, strongly apsacline. Pseudodeltidium much reduced.

Brachial valve with moderately concave umbo and with concavity extended
forward as a narrow sulcus to the anterior margin or disappearing slightly be-
fore the margin. Flanks bounding sulcus moderately concave or nearly flat.
Cardinal extremities flattened and deflected slightly toward the pedicle valve.
Chilidium deeply cleft to form chilidial plates. Interarea hypercline.

Interior of pedicle valve with small teeth but strongly reenforced fossettes ;
dental plates obscured by secondary deposits; apex of delthyrial chamber filled
by callus deposit into which the adductor impressions are deeply sunk. Adjustor-
diductor fields not widely divergent, subflabellate. Median ridge low and slender,
extending about one-third the length. Pallial marks well impressed. Anterior
and anterolateral portions strongly thickened and papillose. Brachial valve usu-
ally without a greatly thickened periphery; median ridge low and inconspicu-

ous; lateral ridges low, strongly elevated anteriorly ; muscular areas not greatly
thickened.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
THolotyneae ays hick 8.1 7.0 11.9 14.3 1.9 2.6
Paratype (117525c):..<. Out 8.4 12.8 15.2 aK 3.0
a (1175234)... 7.8 7.1 11.9 14.0 1.8 2.3
og (107521)es 7.9 TB II.0 12.4 2.1 2.7
i: (117530a)... 9.0 8.6 12.6 13.6 1.9 213
¢ (117530b)... 7.9 7.4 I1.2 13.5 Might 1.7
if (117526a)... 8.9 8.4 132 14.4 1.9 2.6
% (98206b).... 10.2 0.6 15.0 18.4 2.0 3.0

Types.—Holotype: 117525a; figured paratypes: 98206a-d (Butts), 98207b,
117522, 117523a, 117524a, 117525b, 117526a,b, 117527a,c, 117530a,b; unfigured

796 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

paratypes: 98206a-d, 98027a,c-e, 117519a,b, 117520a,b, 117521, 117523b,
117524b, 117525c, 117527b.

Horizon and locality—Wardell formation and Wardell part of Dryden forma-
tion in Clinchport (T.V.A. 188-NW) Quadrangle, Virginia: At Lloyd Carter’s
barn, 0.8 mile northeast of the new school at Rye Cove; several other localities
in the vicinity of Rye Cove; Mannville School.

Wardell formation (Hesperorthis zone) in Tennessee: On U. S. Highway
25E, Evans Ferry section, 0.8 mile north of Indian Creek, Howard Quarter
(T.V.A. 162-NW) Quadrangle.

Discussion—Sowerbyella socialis occurs in great numbers in several locali-
ties. It is characterized by strongly beaded costellae, acute cardinal extremities,
fairly strong costellae not differeniated into well-marked zones. The species is
most like S. compacta, and the interiors of the two species are nearly identical.
It differs from S. compacta in attaining a somewhat larger size and in having
stronger costellae and stronger beading on their surface. This species is also
suggestive of S. variabilis but has a thicker shell and more robust form. It is
also much more strongly costellate. Sowerbyella socialis differs from S. perplexa,
which it resembles in form and size, in not having its costellae well differentiated
into zones and in having strong beading not possessed by the Chatham Hill
species. Sowerbyella socialis should not be confused with S. lebanonensis be-
cause that is a shorter form and also has its costellae differentiated into zones.

SOWERBYELLA SOCIALIS CRASSA Cooper, new subspecies
Plate 200, B, figures 7-14

Shell of about medium size for the genus, wider than long, and with the length
equal to about three-fifths the width at the hinge. Cardinal extremities acute,
often drawn into small ears. Lateral margins indented just anterior to the cardi-
nal extremity, otherwise straight and oblique; anterior margin broadly rounded,
occasionally subnasute. Surface marked by costellae of unequal size, from 70
to 90 on a valve. First and second generations of costellae narrowly rounded
and high. In 1 mm. at the front of an adult of average size 3 large costellae may
be counted. Between the larger costellae 1 or 2 smaller ones of a third genera-
tion may or may not be intercalated. Costellae strongly spinose.

Pedicle valve moderately convex in lateral profile and forming low swelling
highest in the middle in anterior profile. Beak inconspicuous; umbo slightly
swollen. Fold poorly developed, narrow, often not reaching the front margin.
Valve most convex in the middle and with gentle slopes to the anterolateral and
front margins. Slopes to the cardinal extremities long and gentle. Cardinal
extremities flattened. Interarea long, slightly curved, moderately apsacline.

Brachial valve with moderate concavity, greatest in the midregion; distinctly
sulcate in some specimens. Sulcus narrow, may or may not reach the anterior
margin. Areas bounding most deeply concave part gently concave. Cardinal
extremities flattened, deflected toward the pedicle valve.

Interior like that of S. socialis.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 797

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness Height
Holotype. seit ve. eek 8.0 78 11.3 14.0 1.8 2.4
Paratype (117528b).. 7.1 6.8 10.5 12.4 1.8 2.1

Types.—Holotype : 117528a; figured paratype: 117529b; unfigured paratypes:
117528b; 1175292.

Horizon and locality —Wardell formation and Wardell part of Dryden forma-
tion in Virginia: At Rye Cove and vicinity. Same formation in Tennessee:
50 yards north of the intersection at Thorn Hill on U. S. Highway 25E, Avon-
dale (T.V.A. 162-SW) Quadrangle.

Discussion.—This differs from S. socialis in its still stronger costellae and
the prominent beading on the fine costellae.

SOWERBYELLA SUBCARINATA (Ulrich)
Plate 200, C, figures 15-18

Plectambonites subcarinatus Ulrich (Ms.) in Butrs, Alabama Geol. Surv., Special Rep. 14,
p. 126, pl. 31, figs. 9-15, 1926.

Although this species has been figured, it has never been described. The type
lot contains 6 specimens, not one of which is well preserved. The adult speci-
mens are all badly exfoliated, and the interiors are of young specimens. Con-
sequently, the species is difficult to define. Despite these difficulties the feature
that gives the specific name to the species—the narrow median fold—is suff-
ciently well developed to be distinct even in the peeled specimens. A descrip-
tion of the type material and a few additional topotypes is given below.

Shell of about medium size for the genus, wider than long but with the length
and width variable. Cardinal extremities acute and often produced into small
ears. Lateral margins nearly straight to oblique. Anterior margin broadly
rounded, usually nasute. Surface multicostellate; costellae elevated, narrowly
rounded, slightly narrower than the interspaces. Costellae in 3 generations;
costellae of first 2 generations of about the same size at the margin; I to 2
costellae of the third generation intercalated between those of the first 2 along
the margin. Costellae 6 to 10 in a millimeter at the front and from 80 to 120
in number. Spaces between costellae marked by moderately distant, elevated con-
centric fila.

Pedicle valve moderately strongly convex in lateral profile and with the great-
est convexity in the posterior half. Anterior profile strongly convex with a
hump at the middle, the sides convex and sloping moderately to the lateral mar-
gins. Median fold narrow, strong, often producing the front margin into a small,
blunt nose. Umbo narrowly swollen; beak inconspicuous. Regions bounding
sulcus swollen but not raised above level of fold; slopes to cardinal extremities
steep. Interarea apsacline.

Brachial valve with greatest convexity along line of sulcus corresponding to
the fold; flanks bounding sulcus gently convex or somewhat flattened. Cardinal
extremities deflected.

798 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Interior of pedicle valve with low median ridge extending for about one-third
the length of the valve, forked at the front; diductor-adjustor field wide and
subflabellate ; inner surface coarsely papillose, thickened strongly in the antero-
lateral and lateral regions, and less so at the front. Delthyrial callosity thick.
Brachial valve with median septa low and moderately elevated at the front.

Measurements in mm.—

Brachial Hinge Thick-
Length length Midwidth width ness Height
Lectotype (pedicle valve).......... 8.7 ? 12.9 14.8 ? 3.2
Paratype (pedicle valve 71525b).... 7.8 ? 11.5 10.9 ? 2.6 ?
© Cu Ar RTE S ZOO) waging ? 10.4 TOT fa Ue 2.0
Hypotype (brachial valve 117531e). ? 5.7 9.0 10.4 ? E

Types.—Lectotype: 71525a; paratypes: 71525b-f; figured hypotypes:
117543a-d, 117534a-d; measured hypotype: 11753Ie.

Horizon and locality.—Carters formation in Birmingham (30’) Quadrangle,
Alabama: On Cedar Mountain 2 miles southwest of Argo; quarry 0.3 mile north
of Gate City.

Discussion—The most prominent feature of this shell is the narrow median
fold of the pedicle valve which gives the name to the species. No description of
this species was offered when the name was proposed, the name resting on 7
retouched pictures. The material on which the species is based is poorly pre-
served, and most of the specimens of the exterior are partially exfoliated. The
median fold in itself is not a very distinctive feature because a tendency to such
fold seems to exist in nearly all the species.

Sowerbyella subcarinata is a proportionately wider species than S. nasuta
which is one of the most prominently folded species in the Appalachians. Of
other somewhat carinate forms, this species is distinguished from S. negritus
and S. plicatifera by their different ornamentation. The species is more convex
than S. lebanonensis. Sowerbyella compacta is very close to S. subcarinata, and
a few folded specimens are almost identical in profile and proportions to the
Alabama shell. Folding in S. compacta is not the rule, and the specimens that
so strongly resemble S. subcarinata are unusual ones.

SOWERBYELLA VARIABILIS Cooper, new species
Plate 197, D, figures 35-43; plate 202, EF, figures 27-40

Shell of about medium size for the genus, wider than long, outline semiellip-
tical to subrectangular ; hinge forming the widest part, usually auriculate in the
young and young adult. Sides varying from slightly to moderately oblique; an-
terior margin broadly rounded. Surface marked by costellae of unequal size,
the 2 sizes alternating frequently ; 3 or 4 of the strong costellae occupy the space
of I mm. at the front margin; I to 4 of the finer costellae occupying the spaces
between the stronger ones. Alternation of costellae less marked on the pedicle
valve than on the brachial valve and more pronounced on the front of the pedicle
valve than other parts of that valve.

Pedicle valve fairly strongly and evenly convex and with the maximum con-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 799

vexity located at about the middle ; anterior profile strongly convex in the middle
with long and moderately steep and somewhat concave lateral slopes. Beak
small, umbo somewhat swollen, the swelling continued forward as a poorly de-
fined fold; flanks gently swollen and descending fairly steeply to the lateral
slopes; anterior slope long and steep.

Brachial valve deeply concave with the deepest part forming a poorly defined
sulcus extending from umbo to anterior margin ; areas bounding sulcus less con-
cave than the median region; subperipheral regions concave. Interior with
slightly divergent median septa elevated near the middle; subperipheral rim
moderately thickened ; anterior slope moderately thickened, pustulose, and steep.

Measurements in mm.—

Brachial Hinge :
Length length Midwidth width Thickness Height

1 = (0) (5 347) as yy | 7p 12.2 13.4 1.6 a7
Paratype (117536a).. 6.1 5.8 9.6 12.0 1.2 2.0
4 CLIZ5S7)). LLM FE 12.1 14.2? 1.5 2.6

Types.—Holotype: 117536b; figured paratypes: 117535b,c, 117536a, 117538a,
117539a,b ; measured paratype: 117537.

Horizon and locality—Bromide formation (Pooleville member-O-roplecia
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek near center
Sec, 95,.1. 5 o- WoL L.,.Criner Fills, Carter County: Spring: Creek, ‘Sec. “17,
T.28S., R. 1 W., Murray County ; (370 to 390 feet above base), creek bed west
of U. S. Highway 77, SEANE$ sec. 25, T. 2 S., R. 1 E., Carter County.

Discussion —This species is a thin-shelled form characterized by considerable
depth to the brachial valve, fine, beaded costellae, alate cardinal extremities,
moderate convexity, and well-differentiated costellae. This species differs from
S. vulgata, another Oklahoma species with which it might be confused, in the
differentiated costellae, those of S. vulgata not being so well grouped as those of
S. variabilis. This feature of the costellae distinguishes S. variabilis from simi-
lar appearing Appalachian species such as S. compacta and S. socialis. Sower-
byella lebanonensis has differentiated costellae, but its outline and profiles are
different from those of the Oklahoma species. Sowerbyella perplexa has more
regularly differentiated costellae than S. variabilis and has differently shaped
valves.

SOWERBYELLA VARICOSTELLATA Cooper, new species
Plate 196, A, figures 1-8

Shell small, width at hinge not quite twice the length; anterior margin broadly
rounded; lateral margins gently convex. Cardinal extremities acute, subalate.
Posterior margin nearly straight. Surface marked by costellae of unequal size
that appear in 4 generations. On the pedicle valve the median costella of the
first generation is the strongest one and has the greatest size and height. On
each side of this costella the flanks are marked by 2 to 3 first generation costellae
that extend from the beak to the front margin. Within the areas marked off
by these major costellae 3 generations of costellae may be counted. The second

800 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

generation is almost of the same size as those of the first generation. These 2
generations of costellae separate 2 to 7 of the finer costellae; 14 to 16 costellae
may be counted in 2 mm. at the front of a specimen of average size.

Pedicle valve of even and moderately strong convexity ; most convex portion
at about the middle. Anterior profile unevenly convex with the greatest con-
vexity at the middle and with the sides flat and sloping moderately to the mar-
gins. Beak inconspicuous, protruding very slightly beyond the posterior margin.
Umbo narrowly swollen and passing into the swollen midregion. Slopes to the
cardinal extremities very slight concave, gentle. Anterolateral regions some-
what swollen, occasionally with an obscure plication defined by the strong cos-
tellae. Interarea slightly curved, apsacline.

Brachial valve moderately convex with the greatest convexity located at about
the middle and decreasing anteriorly and laterally. Flanks bounding most con-
cave portion gently convex and with the convexity decreasing most rapidly lat-
erally. Cardinal extremities deflected slightly toward the pedicle valve. Inter-
area short and hypercline.

Interior: Pedicle valve with median ridge short, extending for about one-
quarter the length; diductor scars deeply impressed, strongly thickened along
their inner margins. Outer margins strongly thickened. Internal surface strongly
spinose. Brachial valve with median ridge unusually strong; lateral septa low;
none of the septa strongly elevated at the front. Median elevation of valve mod-
erately strong, thickened at the front and with several spinous processes project-
ing anteriorly from the front.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Holotype 020). F7oeet ik. 4.6 4.0 7.0 7.5 Gy 1.9
Paratype (117533)..... 4.9 ? Ff 8.7 ? Tigich
. (117532e).... 4.8 4.4 7.3 8.5 1.4 1.9
“ 1232564) iow «he 5-5 iy 8.8 11.4? ? 1.8
- CIZI25OC) cued TE 4.9 8.7 11.8 ? ? ?

Types.—Holotype: 117532a; figured paratypes: 117532b-d; unfigured para-
types: 117532e, 117533, 123256a-d.

Horizon and locality——Arline formation (middle and upper) in Tennessee:
On both sides of the old road in the cedar glade, + mile southeast of Friendsville ;
100 yards south of the Negro Cemetery, 4 mile northeast of Friendsville, Con-
cord (T.V.A. 138-SW) Quadrangle; 4 mile south of McMullens, Meadow
(T.V.A. 139-NW) Quadrangle; 3 miles southeast of Knoxville.

Little Oak formation in Alabama: 7 to 8 miles northeast of Branchville,
St. Clair County.

Discussion.—This is a small species with moderately folded pedicle valve, well-
differentiated costellae, moderately concave brachial valve, and acute cardinal
extremities. It is distinguished from S. negritus by the lesser breadth of the
zones of fine costellae set off by the larger radii, smaller size, and less prominent
median folding. It is close to S. silicica but differs in having wider and more

PART, CHAZYAN AND RELATED BRACHIOPODS—-COOPER 8o1

regular zones of fine costellae, thus being intermediate between S. negritus and
S. silicica.
SOWERBYELLA VULGATA Cooper, new species
Plate 198, A, figures 1-22; plate 202, C, figures 16-23; plate 206, B, figures 8-12

Shell of about medium size for the genus, wider than long, hinge forming wid-
est part; semielliptical in outline; sides gently to moderately oblique; anterior
margin rounded ; costellae subequal in size, fairly crowded, variable but ranging
between 5 and 6 to the millimeter at the front margin.

Pedicle valve fairly evenly and moderately convex in lateral profile; anterior
profile broadly and gently convex, the median region broadly swollen with gently
convex, moderately steep alopes. Umbo narrowly swollen, the swelling extended
anteriorly to form a low fold; interarea steeply apsacline.

Brachial valve deeply concave and with a fairly well defined sulcus running
from umbo to anterior margin; flanks moderately concave.

Pedicle interior with wide and short diductor scars and moderately long, thick
septum separating them. Brachial interior with low median septa and broad and
long adductor scars. Anterior slope long and fairly steep.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height

TLOLOEY Pe, «isis lcie ste toe 7.4 7.0 II.0 12.5 1.5 2.2
Paratype (117543b).. 7.2 6.9 10.5 11.4? 1.6 ae
(TI75431) <: 6.3 6.0 9.1 9.7 1.6 1.9
ie (117543g).. 6.4 6.1 10.0 ELT es 2.0
ok CET7SA08 ice) IEE 6.9 II.0 13.0 1.5 2.4
ie (at7s4ta).. 63 6.1 10.4 12.0 1.4 2.0
i (11754Ie).. 6.9 6.4 10.0 12.2 1.5 2.2

Types.—Holotype: 1175438, figured paratypes: 117540a-d, 117541a, 1175422,
b,e, 117543b-d,f; unfigured paratypes: 117541b-e, 117542c,d, 117543¢,g.

Horizon and locality Bromide formation (Mountain Lake member) in Okla-
homa: In the road cut on Oklahoma Highway 18, 1.8 miles south of Sulphur,
Murray County; Spring Creek, N3 sec. 17, T. 2 S., R. 1 W., Murray County ;
Mountain Lake, E} sec. 22, T. 2 S., R. 1 W., Carter County; on Tulip Creek,
SWIiNWIiNE4 sec. 25, T. 2 S., R. 1 E., Carter County.

Discussion—This is a variable species characterized by moderate size and
convexity, moderately concave brachial valve and poorly differentiated costellae.
It differs from S. plicatifera and S. variabilis, both Oklahoma species, in lack-
ing marked differentiation of the costellae. The species is suggestive of S. com-
pacta of the Appalachian Valley region in size, shape, and profiles but is a more
deeply concave and less robust species. It differs from S. socialis in having
much finer and less strongly beaded costellae.

The costellae of this species are somewhat variable, specimens occurring with
moderately strong costellae but others in which the radii are distinctly finer. No
clear-cut separation between the two kinds proved possible and they are regarded
as constituting one species.

802 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

SOWERBYELLA sp. 1
Plate 268, A, figures 1, 2

Small, semielliptical in outline, wider than long; sides gently convex, slightly
oblique; surface with differentiated costellae, 2 of the larger costellae in the
space of 1 mm. and the space between the larger costellae occupied by 2 to 4 fine
costellae.

Pedicle valve moderately convex and with the greatest convexity at about the
middle; anterior profile broadly convex, the median region slightly narrowed;
lateral slopes long and moderately steep. Median region with a narrow but in-
distinct fold; flanks gently convex.

Brachial valve moderately concave, deepest in the median region but flattening
laterally to the posterlateral extremities which are flattened.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
WE PSAAAY oe ete oes 6.8 6.2 9.8 11.4 we 2.2
LIZ544D BUA Re ai | 6.6 10.2 10.5 1.8 2.4

Figured specimen.—117544a ; measured specimen: 117544b.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: 68 to 84 feet above the basal sand on Spring Creek, sec. 17, T. 2 S.,
R. 1 W., Murray County.

Discussion.—This species suggests S. vulgata but is smaller, more swollen
medially and umbonally, and with well-differentiated costellae.

SOWERBYELLA sp. 2
Plate 204, B, figures 6-12

Shell of about medium size for the genus, semielliptical in outline; wider
than long and with the hinge forming the widest part ; cardinal extremities auricu-
late; sides gently rounded, slightly to moderately oblique depending on age;
anterior margin broadly rounded; costellae differentiated into fine and coarse,
2 of the latter occupying I mm. at the front and 2 to 4 of the former visible be-
tween the larger costellae.

Pedicle valve gently convex in lateral profile, the greatest convexity located
just anterior to the umbo and with the front half somewhat flattened. Anterior
profile forming a low mound highest in the middle and with long, gentle lateral
slopes. Median region moderately swollen.

Brachial valve moderately concave and with an indistinct narrow sulcus ex-
tending from umbo to anterior margin ; flanks moderately concave ; posterolateral
extremities flattened.

Measurements in mm.—

Brachial Hinge \
Length length Midwidth width Thickness Height
MEZGAbAY es oe cee tes 10.7 10.0 14.5 Tog 2.5 3.6

EIT EASE wake ee 8.4 8.1 11.4 13.4? 1.6 2.3

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 803

Figured specimens.—117545a,b; measured specimen: 117545c.

Horizon and locality—Rodman member of Nealmont formation in Pennsyl-
vania: I mile northeast of Bellefonte, Bellefonte (15’) Quadrangle.

Discussion.—This species is suggestive of S. monilifera from Iowa but is pro-
portionally longer, has a more erect pedicle beak, less swollen pedicle valve, and
shorter pedicle interarea.

SOWERBYELLA sp. 3
Plate 196, G, figures 45-50

Shell small, wider than long, hinge equal to or wider than the midwidth de-
pending on age; costellae well differentiated, 2 of the larger costellae occupying
I mm. and as many as 5 costellae separating the larger ones at the front margin;
posterior margin of both valves marked by prominent oblique wrinkles. Pedicle
valve moderately convex and with the greatest convexity near the middle in
lateral profile ; anterior profile broadly and moderately convex ; umbo and median
region broadly swollen and merged with the flanks. Brachial valve with the
maximum concavity in the umbonal region, rest of valve moderately concave ;
posterolateral extremities flattened.

Measurements in mm.—117546, length 6.9, brachial length 6.5, midwidth to.1,
hinge width 11.2 ?, thickness 1.3, height 2.1.

Figured specimen.—117546.

Horizon and locality—Lower part of the dark shale under the Eureka quart-
zite in Nevada: On the north-facing nose of hill 8167, Martins Ridge, Monitor
Range, Roberts Mountains (1°) Quadrangle.

Discussion —This is a small species with well-differentiated costellae which is
less deep than Sowerbyella sp. 1. It is suggestive of S. silicica but is larger and
does not have the small fold and sulcus of that species. It differs from S. vari-
costellata in not having the pedicle valve subcarinate and the brachial valve dis-
tinctly sulcate.

SOWERBYELLA sp. 4
Plate 196, B, figures 9-14

Shell small, wider than long; hinge wide, cardinal extremities auriculate;
2 large costellae occupying 1 mm. at the front margin and large costellae sepa-
rated by a maximum of 5 fine costellae. Pedicle valve gently convex in lateral
profile ; anterior profile narrowly rounded in the middle with the sides somewhat
depressed and sloping steeply to the margins. Median region subcarinate; fold
low; flanks gently inflated. Brachial valve not deeply concave, deepest along
the median line in the form of a narrow sulcus extending from umbo to
anterior margin. Sides gently convex to flattened.

Measurements in mm.—
Brachial Hinge
Length length Midwidth width Thickness Height
Ty dsY7 y ae ime P54. MN 6.1 5.7, 8.4 8.3 ? 123 1.9
PIG SAGA eS cee toeec ats 5.1 4.9 6.9 8.0 1.4 2.0

PI7ZSASD eset e ee Se as 5.3 5.1 Gin 8.2 2 1:7

804 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Figured specimens.—117548a,b; measured specimen: 117547.

Horizon and locality—yYellow shaly limestone above 25-foot sandstone of
Eureka group in Nevada: Saddle just north of hill 8167, Martins Ridge,
Monitor Range, Roberts Mountains (1°) Quadrangle.

Discussion—This species is suggestive of S. silicica nana in its possession of
a fold and sulcus, but it has a much less swollen and less carinate pedicle valve,
although one brachial valve is more deeply concave medially.

Genus CHONETOIDEA Jones, 1928
Chonetoidea Jones, Mem. Geol. Surv. Great Britain, Paleont., vol. 1, pt. 5, p. 393, 1928.

CHONETOIDEA VIRGINICA Cooper, new species
Plate 215, H, figures 30-33

Shell small, wider than long with the hinge forming the widest part; cardinal
extremities subacute; sides slightly oblique; anterior margin broadly rounded;
multicostellate, costellae uneven in size; about 12 of the large ones may be
counted at the front margin, but only 6 of these reach the umbo. Space between
larger costellae marked by numerous fine threads.

Pedicle valve gently convex in lateral and anterior profile; median region sub-
carinate ; flanks somewhat flattened. Interior without dental plates but with a
short, thin median septum occupying the delthyrial region. Muscle field small,
diductor scars subparallel and short. Anterior margin marked by numerous short
striae.

Brachial valve flat to slightly concave in anterior and lateral profiles. Umbo
concave; rest of valve nearly flat. Interior with short brachiophores, narrow
and shallow notothyrial cavity and short median ridge located at about the middle
of the valve. Lateral ridges in the form of elongate nodes or short ridges, 3 or
more on each side of the median ridge and the inner 2 of them located close
to the median ridge. Adductor field large.

Measurements in mm.—Holotype, length 3.2, brachial length 2.8, midwidth
4.3, hinge width 5.5, thickness ?.

Types.—Holotype: 111097c; figured paratypes: 111097a,b; unfigured para-
type: 1110974.

Horizon and locality—Edinburg formation (Liberty Hall facies) in Virginia:
From a bluff on the north fork of the Shenandoah River 4 mile above the south
fork, opposite the bridge, Riverton, west of Front Royal, Front Royal (15’)
Quadrangle.

Discussion.—No other American species of this genus is now known to which
this one can be compared. It differs from the British species C. papillosa (Reed)
in having the costellae separated into fairly regular groups by the larger costellae,
in having a nearly flat brachial valve, and in details of the brachial interior.

ANISOPLEURELLA Cooper, new genus
(Greek an, not; isos, equal; pleuron, rib)

Shell small in all known species, wider than long with the hinge forming the
widest part. Cardinal extremities acutely angular, often alate. Lateral profile

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 805

concavo-convex. Interareas as in Sowerbyella. Surface of both valves orna-
mented by costellae of unequal size; a few stronger costellae stand out in a field
of finer, closely crowded costellae which may be cancellated by concentric fila.
Pseudodeltidium of pedicle valve well developed; chilidium highly arched.

Inside the pedicle valve the muscle field is small and confined to the posterior
quarter of the valve. Adjustor-diductor impressions small, widely divergent, not
separated by a septum. Brachial cardinalia like Sowerbyella with cardinal proc-
ess frozen to the brachiophore bases to form an inverted V. Brachial processes
long and slender, nearly parallel to the posterior margin. Adductor field bilobed
with the ends of the lobes thickened ; anterior and posterior patches of each lobe
separated by a prominent septum pointing toward the anterolateral curve of the
front margin. Median septum short, located at about the center and mostly con-
fined to that part of the valve. Two pallial trunks originate at the end of the
median septum.

Genotype.—Antsopleurella tricostellata Cooper, new species.

Discussion.—This is an uncommon genus now known chiefly from limestone
associated with black shales. It occurs in Great Britain as the Upper Bala
“Sowerbyella”’ quinquecostata McCoy. This interesting little shell may be identi-
fied by its generally sowerbyelloid form, generally low convexity, and two sizes of
costellae. The interior of the brachial valve is also distinctive in the rounded
adductor areas on each side of a low and delicate median septum. These areas
are usually oval in outline, the narrow part of the oval directed posteromedially
and the expanded part facing the anterolateral extremity. The areas are bounded
by a curved and elevated rim, and each is divided more or less evenly by a short
oblique ridge. The cardinalia are like those of Sowerbyella, but the cardinal
process was not seen as a vertical ridge although the tentlike structure is present.

ANISOPLEURELLA INAEQUISTRIATA Cooper, new species
Plate 193, B, figures 5-9

Shell small, width between 24 and nearly 3 times the length. Cardinal extremi-
ties acute, with small ears. Lateral margin strongly indented just anterior to the
ears in young specimens but very slightly rounded and oblique in adults. An-
terior margin broadly rounded to nearly straight. Commissure uniplicate except
at the cardinal extremities. Surface multicostellate, marked by costellae of 3
sizes. On the young and the more youthful adults the shell is divided into
4 sectors of about 45° each by 3 strong costellae, 1 central one, and 2 lateral ones
that extend to the anterolateral margins. In older adults the prominence of these
3 costellae at the front of the valve is obscured by the presence of many costellae
of intermediate size, but even in these older specimens the 3 major costellae stand
out. The 2 stronger sets of costellae are set in a bed of very fine costellae about
17 in 1 mm. This figure usually includes at least 2 costellae of intermediate size
of which there are about 21 including the 3 primary costellae. All the costellae
are cancellated by fine concentric fila. In addition to these, fine concentric undu-
lations are present.

Pedicle valve unevenly convex with the greatest convexity in the anterior half

806 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

where the valve is somewhat geniculated and the posterior half flattened. An-
terior profile a very gentle bow with the highest part in the middle. Posterior
margin nearly straight. Beak and umbo swollen and standing above the posterior
margin and with the beak protruding slightly beyond the posterior margin. Cen-
tral part slightly swollen and more prominent than the flanks which extend by
a gentle slope to the cardinal extremities. Anterior and lateral slopes steep.

Brachial valve with moderately concave umbonal region but strongly concave
in the median part. Flanks bounding deepest part somewhat flattened. Cardi-
nal extremities deflected toward the pedicle valve. Interarea anacline.

Measurements in mm—

Hinge
Length Width width Thickness
PAGCOR vs hoe ra tolta ns 'siaSice lends Bete 4.3 9.6 11.5 ?
Paratype (IIOD2ZOD) 22... ias6.s 8 ate ors 5% 3.8 7.3 0.7 ?
~ (F809280C)% tay chyna l ee ete 4.2 8.0 8.9 ?

Types.—Holotype: 110929a; figured paratypes: 110924, 11092Qb-d.

Horizon and locality—Whitesburg formation in Tennessee: 14 miles west of
Bulls Gap, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Chatham Hill formation in Virginia: On the Grayson Farm, 4 miles south-
west of Bland, Bland County.

Discussion—Compared to A. tricostellata, this species is much larger, more
convex, and has more numerous large costellae.

ANISOPLEURELLA TRICOSTELLATA Cooper, new species
Plate 193, A, figures 1-4; plate 195, A, figures 1-5

Shell small, about twice as long as wide at the hinge; cardinal extremities
acutely angular ; lateral margins slightly convex, front margin broadly rounded.
Surface marked by costellae of unequal size ; 3 costellae stronger than the others
divide the shell into 4 parts; 1 costella originates at the umbo and extends to
the anterior margin, the other 2 extend to the anterolateral margins. The sur-
face between the stronger costellae are marked by very fine, crowded costellae of
unequal size and numbering about 12 or 13 in I mm. at the front margin. Cos-
tellae cancellated by fine concentric fila. Flanks marked by interrupted concen-
tric undulations.

Pedicle valve moderately convex, with the greatest convexity at about the
middle; beak protruding very slightly beyond posterior margin; umbo swollen ;
portion of shell occupied by 2 medial quadrants as marked off by strong radii
inflated ; outer flanks flattened; posterior margin defined by a thickened rib or
costella diminishing in size toward the beak.

Brachial valve gently concave with the maximum depression at the middle;
flanks and cardinal extremities somewhat flattened. Adductor field forming 2
well-rounded and large lobes, each lobe divided by an oblique ridge; median
septum short and slender. Cardinalia as in Sowerbyella.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER ~ 807

Measurements in mm—

Brachial Hinge
Length length Midwidth width Thickness Height
Piolotype ets fet. 3 2.9 2.6 5.0 6.4 0.4 0.8
Paratype (i110925a).... 3.8 ? 6.4 8.9 ? ? 0.7
4 (110925b).... 3.9 ? 6.7 7.8 ? 1.1

Types.—Holotype: 117475b; figured paratypes: 110g25a-d, 117475a; un-
figured paratype: 117475c.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species is characterized by its low convexity and the pres-
ence of 3 prominent costellae, 1 median one and 2 lateral ones. These features
distinguish this species from A. inaequistriata which is more convex and has
numerous large costellae.

Genus EOPLECTODONTA Kozlowski, 1929

Eoplectodonta KozLowsk1, Palaeont. Polonica, vol. 1, No. 1, pp. 30, 113, 1920.

This genus was proposed for sowerbyelloids having a partially denticulate
hinge line. Actually the genus has some combinations of ornamentation and in-
terior characters that will serve to distinguish it from Sowerbyella and other
members of the Plectambonitacea.

All the known species of Eoplectodonta are characterized by ornamentation
in which larger costellae define bands of smaller radii of greater or less width.
The species also are characterized by a prominent oblique wrinkling of the pos-
terior margins. These features occur in some other genera, such as Sowerbyella,
but in that genus the wrinkling of the hinge is usually a variable feature whereas
it appears to be constant in Eoplectodonta. Furthermore, no species of Eoplecto-
donta is now known in which the finer costellae are beaded as in American
Porterfield, Wilderness, and Trenton species,

Inside the pedicle valve the arrangement of the muscle and pallial trunks is
like that of Sowerbyella, but Eoplectodonta does not have the forked arrange-
ment at the anterior end of the septum so common in the former genus. Inside
the brachial valve the feature of most importance is the development of the
median septum to a stage equal to or surpassing that of the lateral septa. This
produces 3 almost uniform septa which are only slightly divergent. These rise
to a crest near the center of the valve as in Sowerbyella and usually have a steep
papillose anterior slope. The triradiate pattern of the septa is very distinctive.
This feature appears in one species of Sowerbyella and suggests that Sowerbyella
is the ancestor of Eoplectodonta.

Eoplectodonta is well represented in the British Llandovery fauna which in-
cludes E. praecursor, the genotype, and E. duplicata. Plectambonites schmidti
Tgrnquist of Etage 5b from Norway appears to belong here. The American
species are much older than the British forms.

808 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

EOPLECTODONTA ALTERNATA (Butts)
Plate 184, A, figures 1-3; plate 207, B, figures 2-25; plate 208, A, figures 1-18;
plate 269, E, figures 23, 24
Sowerbyella alternata Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 100, pl. 95, figs. 22, 23,
1942.
eae sp., ibid., p. 109, pl. 95, figs. 20, 21.

Shell large, wider than long, length about two-thirds the width. Cardinal
extremities acute or rounded and obtuse, depending on age. Lateral margins
nearly straight or moderately rounded. Anterior margin broadly rounded to
nasute. Anterior commissure sulcate. Hinge forming widest portion of shell in
young but narrower than width at middle in old valves. Surface multicostellate,
costellae of unequal size, about 30 of the larger ones at the front margin sepa-
rated by from 3 to Io of the finer ones. The latter costellae are low, rounded,
crowded, and with interspaces much narrower than the costellae. Larger cos-
tellae rounded and elevated. Fine concentric fila and wrinkles along the pos-
terior margin complete the ornamentation; as many as 18 wrinkles occurring
on each side of the beak.

Pedicle valve with low beak, protruding very slightly posterior to the posterior
margin. Umbo slightly swollen, extended forward as a low, narrow fold. An-
terior profile narrowly arched with the greatest height at the narrow fold and
the gently convex sides sloping steeply to the margins. Lateral profile with the
greatest convexity located in the umbonal region. Cardinal extremities deflected
toward the pedicle valve to form small ears. Interarea curved, orthocline.
Pseudodeltidium strongly arched, fairly large.

Brachial valve deeply concave with the deepest part in the posterior half; not
strongly sulcate. Cardinal extremities deflected toward the pedicle valve; inter-
area nearly flat and usually nearly in a plane with the interarea of the pedicle
valve and therefore nearly orthocline in position.

Pedicle valve with muscle field short, extending about one-quarter the length;
adjustor-diductor marks elliptical in outline, widely divergent, separated by a
short, stout median ridge. Adductor impressions forming small pits. Teeth
small ; hinge denticles about 6 or 7 in number. Entire surface papillose. Brachial
valve with septa extending to about the middle where they are moderately ele-
vated. Median septum stronger than the lateral septa. Adductor impressions
indistinct.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Hectotype’ ne Bae. 2% 11.0 ? 15.6? ? ? 4.4
Hypotype (79419a)...... 12.7 ? 17.8 17.2 ? 5.0
: C7QATOD) si 0's « 13.8 ? 19.0 20.8 ? 6.7
i (110993d)..... 12.0 12.0 20.3 21.6 ? ?
" (117551-1) .... 16.1 ? 20.7 19.6 ? 8.0
aS 127552) eae: 13.8 II.0 19.3 20.2 ? 4.9
ve (117550b)..... 139 r7.2 18.2 18.0 a1 6.1
a (2T7VES0G) .. . 4s 13.3 Ter 18.2 16.0 Eile 5.7

- CLI75S50d) . 0s 13.1 II.4 ‘19.0 18.0 2, 5.5

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 809

Types.—Lectotype: 97544a ; paratypes: 97543a-c; figured hypotypes: 794194,
d-g, 110985, 110993a-h, 111798a,b, 117549a, 117550b,d, 117551g,l,n,q, 124231a,b;
measured hypotypes: 79419b, 117550c, 117552.

Horizon and locality—Oranda formation in Virginia: North of the road
0.6 mile northwest of Linville Station; just west of the junction of Virginia
County Highways 617=910, and 777, on 777, 4 mile north of Green Mount
Church, Broadway (15’) Quadrangle. Along the railroad 4 mile west of Stras-
burg; on U. S. Highway 11, 2 miles southwest of Strasburg, Strasburg (15’)
Quadrangle ; just east of Battlefield Crystal Caverns, 1 mile north of Strasburg ;
Bowman Farm, 0.3 mile east of U. S. Highway 11, south edge of Woodstock,
Edinburg (15’) Quadrangle; south side of U. S. Highway 33, 0.2 mile west
of Harrisonburg city limits, Harrisonburg (15’) Quadrangle.

Basal Martinsburg formation in Virginia: 0.6 mile northwest of Linville Sta-
tion, Broadway (15’) Quadrangle.

Martinsburg formation (part with Brongniartella=Salona) in Virginia: On
Virginia County Highway 617=910, 0.15 mile north of Green Mount Church,
Broadway (15’) Quadrangle.

Oranda formation in Pennsylvania: 1 mile northwest of Guilford Springs,
24 miles southwest of Chambersburg, Chambersburg (15’) Quadrangle; Carlisle,
Carlisle (15’) Quadrangle; 1 mile south of St. Thomas, Mercersburg (15’)
Quadrangle.

Salona formation in Pennsylvania: On Fishing Creek at Salona, Lock Haven
(15’) Quadrangle.

Dark shale under Eureka quartzite in Nevada: In the north-facing nose of hill
8167, and 4.2 miles north-northeast of Martin Ranch, Monitor Range; under
2 knobs of Eureka quartzite, north side canyon, 3.1 miles N. 32° E. of Blair
(Segura) Ranch, Antelope Mountains, Roberts Mountains (1°) Quadrangle.

Discussion.—This species can generally be recognized by its large size, usually
strongly convex pedicle valve, the beautiful ornamentation and the elaborate
wrinkling of the posterior margins of both valves. As here described the species
occurs in the Oranda and succeeding Salona formation, particularly near Green
Mount Church north of Harrisonburg.

Eoplectodonta alternata was originally inadequately described, the description
consisting of two lines and the comparison being made to another species belong-
ing to a different genus. The cotypes consist of four specimens, all of them poor.
The best specimen, 97544a, is selected as lectotype. This specimen shows the
ornamentation and the general form of the species, but no other details are
preserved.

This species is quite variable in profile and outline. Some of this variability has
to do with age of the specimens and some of it with preservation. The younger
specimens are flatter than the older ones and the beak is often visible when the
shell is viewed from the full exterior. In the older adults the beak migrates an-
teriorly as the shell grows, and the beak is obscured in the same view by the
swollen umbonal region. The development of the fold on the pedicle valve is
also a variable feature. In some specimens no distinct fold is visible, but in others

810 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the fold is narrowly rounded and conspicuous, often causing the anterior margin
to become somewhat nasute. In one specimen 2 narrow folds were produced,
but this is quite unusual.

Eoplectodonta alternata is not likely to be confused with any other known
species in lower Middle Ordovician rocks. Its large size, tumid valves, rounded
sides, strong wrinkling, and the good development of denticles all distinguish
it from E. ? dubia. The form and convexity of the valves differentiate this
species from E. foerstei.

EOPLECTODONTA ? DUBIA Cooper, new species
Plate 207, A, figure 1; plate 209, C, figures 8-13

Shell of about the usual size for the genus, wider than long, with the width
at the hinge not quite twice the length. Cardinal extremities acute, often alate.
Anterior margin broadly rounded; lateral margin variable. Surface marked by
costellae of unequal size; young shells marked by about 11 strong costellae sepa-
rated by about I0 fine, crowded lines. In full-grown specimens the sectors de-
fined by the primary strong costellae are divided by costellae of intermediate
size, and these are separated from the larger costellae by 4 to Io of the fine cos-
tellae. About 7 costellae occupy a space of I mm. at the front margin. Posterior
margin wrinkled.

Pedicle valve gently convex in lateral profile with the greatest convexity in
the posterior portion of the valve. Center part swollen to form a low fold. Flanks
slightly convex, descending to the cardinal extremities with a gentle slope. Inter-
area apsacline.

Brachial valve with the greatest concavity in the umbonal and median regions,
somewhat flattened in the vicinity of the cardinal extremities and anterolateral
region. Interarea hypercline.

Interior: Pedicle valve with adjustor-diductor impressions short, deeply im-
pressed, somewhat elliptical in outline. From the anterior end of this muscle
field a strong pallial trunk is sent out anterolaterally. Dental plates short, promi-
nent, not hidden by callus. Accessory dental arrangement obscure, if present.
Inside the brachial valve 3 septa extend to about the middle of the valve; the
median septum is the highest and best developed of the 3. Interior of both valves
strongly granulose. No hinge denticulations seen.

Measurements in mm.—
Hinge

Length Midwidth width Thickness
Holotype (pedicle valve) ........s.e008 10.1 16.3 18.9 ?
Paratype ( “ 2 ap7ssha )vie eine 9.3 14.4 18? ?
" CLeget: oe PRIZE SSD) po euctersrew’s 8.3 13.7 16.2 ?
. a al hi jk Le SE Nase cleaieals 8.0 14.1 ? ?
i (brachial valve 117555e)....... 6.7 10.1 13.0 ie
~ phen ee ELT SSSI cee 7.8 10.9 13.5 ?

Types.—Holotype: 117555d; figured paratypes: 110984, 117555b,f-h; un-
figured paratypes: 117555a,¢,e.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER SII

Horizon and locality—Edinburg formation (Cyrtonotella zone) in Virginia:
Ravine on south side railroad, 4 mile west of Strasburg, Strasburg (15’) Quad-
rangle.

Botetourt formation in Virginia: Junction Virginia Highways 731 and 724,
2 miles northwest of Brownsburg, Lexington (15’) Quadrangle.

Discussion.—This species is placed in Eoplectodonta with a query because no
denticles were seen along the hinge in any of the specimens studied. Although
the hinge seems to be edentate, the other characters, internal and external, seem
to be those of Eoplectodonta. On the outside the ornamentation with its large
costellae separating broad bands of fine radii and the prominent wrinkling along
the posterior margin are all characteristic features of Eoplectodonta. On the
inside of the brachial valve prominent development of the median septum is
characteristic although the development of the muscle callosities and the nar-
rowed, elevated front are not carried to the extent that is usual in geologically
younger species.

Eoplectodonta ? dubia differs from E. foerstei and E. alternata in having less
robust and convex valves and in lacking hinge denticulations.

EOPLECTODONTA FOERSTEI Cooper, new species
Plate 209, A, figures 1-3

Shell moderately large, wider than long with the length equal to about two-
thirds the width. Cardinal extremities acute and mucronate in the young but
rounded and obtuse in large adults. Lateral margins of adult gently rounded ;
anterior margin broadly rounded. Surface marked by costellae of several sizes.
In the half-grown stage the ornamentation consists of costellae of 3 sizes, the
larger costellae standing out prominently and producing a slight plication of the
valve and separated by about 1o of the finer costellae. Among the finer costellae
occurs an occasional costella of intermediate size. In the adult half of the shell
costellae of the stronger and intermediate sizes predominate and are separated
by 1 to 4 finer costellae. In the young half of the valve strong oblique wrinkles,
about 8 on each side of the hinge, are conspicuous. These are not carried on in
the later growth stages and are thus confined to the young half of the valve.
Fine concentric growth fila complete the ornamentation.

Pedicle valve only gently convex in the young and with a fairly prominent
low fold in the posterior half. Lateral profile of the adult strongly convex with
the greatest convexity in the posterior third. Anterior profile of adult forming
a very convex arch with steeply sloping sides. Fold of the young stages lost
before the middle of an adult. Anterior half of an adult somewhat tumid and
with moderately steep slopes to the margins. Slopes to cardinal extremities con-
cave and steep. Cardinal extremities deflected toward the pedicle valve. Beak
small, protruding slightly beyond the posterior margin. Interarea slightly curved
and orthocline in position. About 14 denticles are visible on one side of the
hinge of No. 110992c, but this may not be the full complement because this side
of the valve is broken.

812 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Exterior of pedicle valve unknown.

Interior: A fragment of brachial valve preserving the front portion and the
ends of the median septa shows the middle septum to be highest and longest of
the 3 as usual in the genus.

Measurements in mm.—

Brachial Mid- Hinge Thick-
Length length width width ness Height

Holotype (pedicle valve)............ 11.9 ? 17.7 16.97” F 4.2
Paratype ( “ Ss osp Roggab 4 Li, 10.8 r iy ees ? ? ?
ff @ Sir mmodo2t)}. alst 7.7 ? 12.9 14.4 ? ?

Types.—Holotype: 110992a; figured paratype: 110992d ; unfigured paratypes:
110992b,c,e-f.

Horizon and locality—Wells formation in Tennessee: Along the railroad,
14 miles southwest of Cumberland City, Wells Creek Basin, Stewart County.

Discussion.—This species is proportionately wider and less convex than E. al-
ternata which it approaches in size although it never attains the large dimen-
sions of the Oranda and Salona species. The zones of fine costellae in the Ten-
nessee species are less wide, and many more of the strong costellae appear in
the ornamentation of EF. foerstet.

EOPLECTODONTA ? TRIRADIATA (Butts)
Plate 203, B, figures 16-20

Sowerbyella rugosa triradiata Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 113, pl. 96,
fig. 9, 1042.

Shell small, somewhat trapezoidal in outline; the hinge forming the widest
part; sides gently oblique; anterolateral extremities narrowly rounded; anterior
margin straight. Surface marked by costellae of unequal size, 3 of which are
more prominent than the others: 1 is median and the other 2 extend from the
beak to the anterolateral extremities. Space between large costellae filled by a
mat of finer costellae of 2 or 3 sizes.

Pedicle valve unevenly and narrowly convex in lateral profile, the posterior
half convex, the anterior half flattened and the place of geniculation narrowly
convex ; anterior profile subrectangular, the median part nearly flat but the sides
short and descending steeply. Umbo and beak small; region posterior to angle
of geniculation gently convex; angle of geniculation about 85° ; region posterior
to angle shorter than the trail ; anterior slope of trail long and steep; trail broadly
sulcate in the median region; sides steep and set off from the trail by narrowly
rounded anterolateral folds. Interarea long, apsacline.

Brachial valve and interiors not known.

Measurements in mm.—

Hinge
Length Midwidth width Thickness Height Surface
PABIGEY DE As ac} nptoteultns * « 5.5 9.8 II.0 ? 1.4 5.8

Hypotype (123257a).... 6.6 9.1 9.5 ? 2.9 9.5
Types.—Holotype: 97582b; paratypes: 97582a,c; figured hypotype: 123257a.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 813

Horizon and locality—Oranda formation in Virginia: In the railroad cut
4 mile west of Strasburg, Strasburg (15’) Quadrangle.

Discussion.—This species can be readily recognized by the 3 prominent cos-
tellae on the surface and the strong geniculation near the middle. The holotype
briefly noticed by Butts is undoubtedly a youthful specimen which has not yet
geniculated. The hypotype figured herein shows the full geniculation and indi-
cates clearly that this species has nothing to do whatsoever with S. rugosa of
the Eden and Martinsburg formations.

Sowerbyella ° triradiata Butts is most like Plectambonites quinquecostata
sublobata Reed from the Balclatchie formation, Girvan District, Scotland. From
measurements taken from Reed’s figures it is evident that his species is a much
larger one and apparently less strongly geniculated than the Oranda form. His
has the same triradiate ornamentation so characteristic of Butts’ species. An
interior of a brachial valve figured by Reed suggests an interior like that of
Eoplectodonta rather than Sowerbyella. It shows 3 closely spaced median septa
and 2 lateral septa separating the adductor scars. No denticulations are noted
along the hinge in either description or the figures.

EOPLECTODONTA sp. 1
Plate 192, E, figures 25-28

The specimen illustrated is of particular interest because it is probably a young
one and because it shows clearly the partially denticulate hinge which is regarded
as an important character of the genus. The small size and gentle contours of
the profiles of this specimen are also indicators of youth. This specimen was taken
from the siltstone 30 feet above Echinosphaerites zone in the lower part of the
Edinburg formation in Virginia, 14 miles south of Wadesville, Winchester (15’)
Quadrangle. It thus indicates a fairly early appearance of the denticulate hinge
line. This specimen is of approximately the same age as E. ? dubia, but none
of the specimens of that species showed clear development of denticles.

Figured specimen.—117556.

Subfamily XENAMBONITINAE Cooper, new subfamily

Sowerbyellidae having a small elevated visceral disk.

XENAMBONITES Cooper, new genus

(Greek xenos, strange; ambon, umbo)

Shell small, semielliptical in outline; hinge wide, cardinal extremities acute ;
plano- to concavo-convex; anterior commissure deeply sulcate; surface finely
costellate.

Pedicle valve with moderately long interarea; anterior with prominent, broad
median fold ; teeth small, simple ; muscle area wide but short, somewhat rectangu-
lar in outline; dental plates vestigial; trough corresponding to fold anterior to
muscle area may or may not be occupied by an inverted V-shaped cavity ; ovarian

814 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

impressions fairly large, bounded on the side nearest the median line by a low
ridge. Delthyrium open in the adult.

Brachial valve deeply sulcate, the sulcus on the inside forming a high, rounded
ridge which serves as a median septum; sockets narrow, slitlike ; brachiophores
thin, short, flat blades intimately fused with a convex plate that arches over the
notothyrium ; a septumlike cardinal process and intergrown brachiophores form-
ing an arched plate suggest the tentlike structure of Sowerbyella; visceral disk
short, strongly elevated toward the pedicle valve, somewhat expanded laterally
and produced into a long point anteromedially.

Genotype.—X enambonites undosus Cooper, new species.

Discussion.—This genus is one of the most peculiar of all the plectambonitids.
It will not be confused with any other because of its nearly horizontal wrinkling
and the elaborate development of the anterior margins. The fold is very strong
and is also well marked in the young. When adulthood is reached the pedicle-
anterior wrinkles in the direction of the pedicle valve to form a narrow marginal
fold which makes 2 concave areas of the anterior portion of the flanks. Internally
the margin is marked by a carinate ridge which slopes obliquely inward toward
the middle to form the slip over which the geniculated edge of the brachial
valve fits.

The interior of the pedicle valve is somewhat suggestive of Leptellina in its
short and wide, subrectangular muscle area which is lodged in the delthyrial
cavity. The lateral margin is formed by vestigial dental plates which are barely
visible. The anterior end of the muscle area is excavated to form an inverted
V-shaped chamber as the median part of the valve deepens. A second V-shaped
chamber may be developed in the trough of the pedicle valve anterior to the
muscle area. This one is probably created by the main trunks of the vascula
media which travel anteriorly on each side of the median trough. Not one pedicle
valve showed clear-cut trace of a pseudodeltidium. The genus probably had one
in young stages, but none of the young specimens preserves it.

The brachial valve has the anterior margin strongly geniculated toward the
pedicle valve. This geniculated edge fits over the carinate subperipheral rim in
the pedicle valve. The brachial valve thus forms a boxlike lid to the pedicle valve.

None of the brachial valves showed any clear trace of a vertical median sep-
tum on the tentlike brachial structures. The preservation is not good, but if
such a septum were present a trace of it should appear. The arched plate which
is welded to the brachiophores overhangs the peculiar visceral disk. The latter
is short but strongly elevated. It is narrowly folded in the middle to form a low
median ridge which extends somewhat obliquely toward the pedicle valve and
is produced at its anterior extremity into a long, sharp point. The sides of the
disk cover the anterior parts of the valve. No trace of pallial marks was seen on
this portion of the valve, and the muscle marks were not differentiated in the
visceral disk.

No genus is at present known to which this one will closely compare.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 81 5

XENAMBONITES UNDOSUS Cooper, new species
Plate 195, D, figures 17-31; plate 268, F, figures 25-28

bd

cardinal extremities narrowly rounded to mucronate; sides strongly oblique,
nearly straight ; anterior margin narrowly rounded. Surface marked by closely
crowded, threadlike costellae and transverse wrinkles parallel to the hinge and
located in the posterior half. Fold and sulcus bounded on each side by a costella
stronger than the surrounding ones.

Pedicle valve gently convex in lateral profile but with the umbo somewhat nar-
rowly rounded; anterior profile with median region narrowly humped up and
sides depressed and gently concave; fold narrow and rounded and including the
narrow, swollen umbo; sides of fold moderately steep; flanks gently swollen but
depressed below the fold; anterior and lateral margins marked by a narrow
convex fold which is moderately elevated in the anterolateral region. Interior
margin with elevated, carinate peripheral rim.

Brachial valve uneven in lateral profile, the posterior half gently concave but
the anterior half moderately convex; anterior profile with deep median sulcus
bounded by high, narrow folds. Umbo gently concave, the concavity deepening
anteriorly to form a deep and narrow sulcus; flanks narrowly convex in the
anterior half but flat to gently concave in the posterior half; cardinal extremities
flattened; margins deflected strongly toward the pedicle valve to fit over the
subperipheral rim of the pedicle valve. Interior as described for the genus.

Shell small, semielliptical in outline, with the hinge forming the widest part;

Measurements in mm—

Brachial Mid- Hinge
Length length width width Thickness

Paratype (pedicle valve 117468a)..... 3.8 ? 6.2 8.3 fea te
ie (brachial valve 117468n).... ? 3:3 5.8 6.4 1.3

Types.—Holotype: 117468h; figured paratypes: 117468a,f,g,l,m,r; unfigured
paratypes: 117468b-e,i-k,n-q,s.

Horizon and locality —Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—No other species of this genus is now known to which this one
may be compared. Furthermore, no other plectambonitid has a combination of
features even remotely like this genus.

Subfamily PrycHocLyprinaE Cooper, new subfamily

Sowerbyellinae with poorly developed septa in the brachial valve.

Genus PTYCHOGLYPTUS Willard, 1928
Ptychoglyptus WILLARD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 283, 1928.

Shell thin, rafinesquinoid in outline and profile; interareas well developed ;
interarea of brachial valve the shorter of the two; surface marked by costellae
of 2 sizes and formed in several generations. A few large costellae originating
at the apex and extending to the margin. Costellae of nearly the same size are

816 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

intercalated. Between these larger costellae fine radial lines extend from the
beak to the margin. Between the larger costellae the shell is thrown into nar-
rowly rounded, often chevron-shaped rugae. The rugae may lie obliquely be-
tween the costellae or they may form an inverted V.

Inside the pedicle valve the dental plates are of the receding type, short and
poorly developed. The muscle area is small and nearly confined to the delthyrial
cavity. Diductor impressions small. Vascula media short. Teeth small and
sharp. Pseudodeltidium moderately arched, imperforate. Interarea apsacline.

Brachial interarea anacline; notothyrium partially closed by chilidial plates.
Cardinalia sowerbyelloid. Brachiophores elongate, slender, supported by callus
that joins the cardinal process, chilidial plates, and brachiophores into a tentlike
structure. Internal median septa poorly formed, short but present near the
middle of the valve.

Genotype.—Ptychoglyptus virginiensis Willard (by original designation),
Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 283, pl. 2, fig. 12, 1928.

Discussion.—This genus was described originally as an ornate type of Rafines-
quina, but examination of the interiors indicates that the affinities are with Sower-
byella rather than with Refinesquina. Sowerbyelloid features are revealed by the
ornamentation and the cardinalia.

Ptychoglyptus as now understood characterizes chiefly forms from the Effna
formation and its correlates. This genus has been identified in other rocks than
those laid down in Mohawkian time, but the interiors of the forms referred to
the genus have not been described.

PTYCHOGLYPTUS ? KINDLEI Cooper, new species
Plate 172, B, figures 7-9; plate 172, C, figures 10-12

Wider than long, hinge forming widest part; sides obliquely sloping toward
the middle; anterior margin broadly rounded; larger costellae in 2 or 3 genera-
tions, 6 or 8 on each side of the median line; rugae large, strong.

Pedicle valve faintly convex in anterior and lateral profile in the posterior
three-quarters, more or less strongly geniculated toward the brachial valve in
the anterior quarter; umbo gently and somewhat narrowly swollen; median
region slightly convex; lateral and anterior slopes steep. Interior unknown.

Brachial valve nearly flat to gently concave in lateral profile and with the
anterior quarter turned abruptly in the direction of the brachial valve. Umbo a
hollow pit, median and flank regions gently concave.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype "che es occ s 10.4 ? 27 15.2+ ?
Paratype (66290b).... ? 7.2 12.4 13.7-+ ?
s (G6200f ie. 7.9 13.8 15.4? -+ ?
Si (6620081). enert . ? P ? 1.0

Types.—Holotype: 66290c ; figured paratypes: 66290a,b, 117392a-c, 123254a;
unfigured paratypes: 66290d-g, 123254b.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 817

Horizon and locality.—Boulder in Mystic conglomerate in Quebec, Canada:
In Range 6, Lot 20, Stanbridge Township, about 24 miles north of Mystic.

Table Head series in Newfoundland: At Table Point and Table Point Cove.

Discussion—This species is characterized by its geniculated anterior quarter
and the fairly strong rugae. The irregularity and prevailing greater strength of
the rugae and their tendency not to be curved or chevron shaped is a distinguish-
ing feature of this species that will separate it from the Virginia shell. Some
specimens of P. ? kindlei have few or no rugae in the anterior portions. Gener-
ally the Virginia shell is completely rugose, although some specimens vary from
this generality. The chief distinguishing character between the Canadian and
Newfoundland species and P. virginiensis is the short and abrupt anterior genicu-
lation toward the brachial valve. This feature is so strong that it seems necessary
to question the generic assignment. This assignment is questioned also because
the Canadian and Newfoundland specimens occur at a much earlier age (accord-
ing to present views) than the Appalachian specimens. Furthermore, the interior
details of P. ? kindlei are yet to be determined. The Table Head brachiopod
assemblage is similar in appearance to that of the Botetourt of Virginia and
Tennessee, but when their interior features are determined the Table Head
forms have generally proved to be generically different from the Appalachian
species which they resemble.

PTYCHOGLYPTUS ? MATURA Cooper, new species
Plate 174, C, figures 5, 6

Large for the genus, wider than long, hinge forming the widest part; sides
sloping gently toward the middle; anterior margin gently rounded. Posterior
half rugose, anterior half marked by costellae of 2 sizes, distant strong costellae
in a mat of fine radii, both covering the rugae as well as the anterior nonrugose
shell.

Pedicle valve fairly strongly convex in lateral profile and with the maximum
convexity slightly anterior to the middle; anterior profile broadly convex; umbo
narrowly convex, the convexity extended anteriorly for about one-third the
length; median region moderately swollen, the swelling extending laterally and
anteriorly so that the lateral and anterior slopes are short and moderately steep.

Interior brachial valve unknown.

Measurements in mm.—Holotype, length 17.6, midwidth 24.1, hinge width
27.8+, surface length 19.7.

Type.—Holotype: 111061.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile south-
east of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—This species is characterized by its partly rugose and partly
nonrugose shell. Furthermore, the rugae are longer than usual in P. virginien-
sis. The important character of this species is its large size, fairly strong con-
vexity, and the fact that about the anterior half is nonrugose. It is possible that
specimens of P. virginiensis will ultimately be found which will have a more

818 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

convex profile and a long nonrugose trail. None have yet been found. Speci-
mens of P. ? matura without the trail should be distinguishable from P. vir-
giniensis by the length of the rugae.

PTYCHOGLYPTUS VIRGINIENSIS Willard
Plate 173, A, figures 1-7; plate 173, B, figures 8-12; plate 174, A, figures I, 2; plate 174, B,
figures 3, 4; plate 174, D, figure 7; plate 174, E, figures 8-17; plate 186, H, figures 32, 33;
plate 186, I, figure 34; plate 213, C, figure 22; plate 268, D, figures 12-15
Ptychoglyptus virginiensis WiLLaRpD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 283, pl. 2, fig. 12, 1928.
Playfairia ? pulchra Butts, Alabama Geol. Surv., Special Rep. 14, p. 102, pl. 19, fig. 15, 1926.

Ptychoglyptus pulchrus (Butts) WItLarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68,
No. 6, p. 284, 1928.

Shell of moderate size, somewhat semicircular in outline; width about twice
the length; hinge forming widest part; cardinal extremities subalate to mucro-
nate. Lateral margins gently convex, oblique; anterior margin broadly rounded.
Surface beautifully sculptured, variable, consisting of costellae of 2 sizes and
short transverse wrinkles. The largest costellae appear in 3 generations, a
median strong costella extending from beak to margin and as many as 9 strong
costellae appearing on each side of the median one. Spaces between large cos-
tellae occupied by as many as 12 fine costellae. Wrinkles generally confined to
the spaces between large costellae except in the cardinal region. Rugae gen-
erally short and arcuate posteriorly, chevron shaped.

Pedicle valve very slightly convex in lateral profile, with a narrow but low
median fold extending from the umbo to the front margin. Slopes of fold gentle
and concave. Lateral extremities flattened. Anterolateral portions of shell some-
what flattened. Beak pointed, prominent, narrow, and only slightly protruding
posterior to the posterior margin. Interarea apsacline. Interior as described
under the generic definition.

Brachial valve gently concave in profile with area of greatest concavity form-
ing a shallow trough from the beak to the margin. Lateral areas bounding sulcus
nearly flat. Interarea anacline. Beak obsolete, marked by a pit, so strong is the
bending of the interarea. Interior as described under the generic heading.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width
FLOM fH shi. Rl. c ciealete ckhoteateins 9.1 ? 15.4 20.7
Fiypoty pe (OS237) cies lesa Rove 8.2 ? 11.8 15.0
oi GUTIOS 7A)! sh Gena. same 8.6 ? 13.3 16.0-++
ie (upT0s6a)),. .i..cactews II.2 10.6 16.2 18.8-+
ff (FRAT SD sce saeheee cuba. 5.6 ? 9.0 10.4+

Types—Holotype: M.C.Z. 8626; paratype: M.C.Z. 8627; figured hypotypes:
98231a,a-1,b,b-1, I11042a-c, 111052, 111056, 117397, 117398a-f, 123285b,d,e,f ;
holotype of P. pulchrus Butts: 71475; measured hypotypes: 111056a, I11057a.

Horizon and locality—Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quad-

PART. T CHAZYAN AND RELATED BRACHIOPODS—-COOPER 819

rangle; McNutt Quarry, 12 miles southwest of Bland, Burkes Garden (15’)
Quadrangle; Grayson Farm, 4 miles southwest of Bland, Bland County.

Edinburg formation (Liberty Hall facies) in Virginia: 1.8 miles S. 4° W. of
Bethel Church, 5.9 miles due east of Harrisonburg, Harrisonburg (15’) Quad-
rangle.

Botetourt formation in Virginia: At the junction of Virginia Highways 731
and 724, 2 miles northeast of Brownsburg, Lexington (15’) Quadrangle.

Edinburg formation (Cyrtonotella zone) in Virginia: In the ravine on the
south side of the tracks at the switch 4 mile east of Strasburg Junction, Strasburg
(15’) Quadrangle.

Effna formation in Tennessee: On the south side of Tennessee Highway 66A,
4 mile northeast of St. Clair, Bulls Gap (T.V.A. 171-SE) Quadrangle.

Pratt Ferry formation in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton
(15’) Quadrangle.

Discussion.—This species is one of the most beautifully sculptured brachiopods
occurring in Ordovician rocks. It is readily recognized by its strong, often
chevron-shaped rugae over which costellae of 2 sizes undulate. This species is
variable, but generally the shell is fairly small and is not known to be geniculated.
In the latter respect it differs markedly from P. ? kindlei. It differs from P. ?
matura is size, convexity, and the fact that P. ? matura has at least half of the
anterior part of the shell nonrugose.

The ornamentation of P. virginiensis is somewhat variable. The variability
is seen chiefly in the rugae which are of different sizes. Some of them are long
and extend between 2 distant large costellae, others are short and extend between
closely spaced large costellae. No uniformity was noticed by means of which
finely rugose and coarsely rugose specimens could be separated into species or
subspecies.

Generally the rugae cover the entire shell from beak to anterior and lateral
margins. A few specimens, however, are not completely rugose. Such is the
type specimen of P. pulchrus (Butts). At the same locality numerous specimens
were found which conform closely to P. virginiensis and others which are inter-
mediate in character between the two. It was thought best, therefore, to sub-
merge Butts’ species in the synonomy of P. virgimiensis.

PTYCHOGLYPTUS ? sp. 1

Three specimens from the Mystic conglomerate in Quebec on Range 6, Lot 21,
indicate a species quite unlike P. ? kindlet. This is a finely and completely rugose
species. It is wider than long and with a wide hinge. The brachial valve only
is known, and it is moderately and evenly concave. The valve is not geniculated
at the anterior.

Measurements in mm.—1232992, length 9.1, midwidth 15.3, hinge width 18.4.

Described specimens.—123299a-c.

Horizon and locality.—Mystic conglomerate in Quebec, Canada: On Range 6,
Lot 21, 2.6 miles due north and 4 mile east of Mystic, Stanbridge Township.

820 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. | 127

Superfamily StRoPHOMENACEA Schuchert, 1896

Usually with thin visceral cavity; pseudodeltidium present; foramen apical
when present; cardinal process double shafted ; chilidium present.

Family LEPTAENIDAE Cooper, new family

Compressed to faintly lenticular Strophomenacea with large apical foramen.

Genus LEPTAENA Dalman, 1828
Leptaena DaLMAN, K. Svenska Vet.-Akad. Handl. for 1827, pp. 93, 94, 1828.

LEPTAENA ORDOVICICA Cooper, new species
Plate 208, B, figures 19-21; plate 212, C, figure 32; plate 228, B, figures 8-18

Leptaena tenuistriata Sowerby var. BAssLerR, Cambrian and Ordovician: Maryland Geol.
Surv., p. 260, pl. 40, fig. 2, 1919.

Shell of about medium size for the genus, hinge forming the greatest width,
the cardinal extremities angular and alate. Length equal to about three-fourths
the width at the middle. Lateral margins excavate just anterior to the cardinal
extremities, narrowly rounded at the anterolateral extremities and broadly
rounded at the front margin. Surface unequally costellate, 1 to 2 of the smaller
costellae alternating with the stronger ones. At the front margin 18 costellae
occupy a space of 5 mm. Body with thin concentric undulations.

Pedicle valve with visceral region or body depressed below (brachiad) the rim
marking place of geniculation; umbonal region swollen, the swelling continued
anteriorly as a low fold nearly to the rim of geniculation. Areas surrounding
swollen fold and in front of it concave with gentle slopes from the umbo. Genicu-
lated rim strong, located 12 mm. anterior to the beak, narrowly rounded in sec-
tion, sharply bent at the anterolateral extremities of the body and extending
with a broad curve convex outward to the anterior side of the ear. Angle of
geniculation about 90°. Geniculated part nearly flat in profile, descending steeply
to the anterior margin but less steeply around the sides to the ears. Interarea
short, delthyrium wide, partially covered by a short pseudodeltidium.

Brachial valve closely fitting the pedicle valve; umbo concave with concavity
extended nearly to middle ; between concave area and point of geniculation valve
is gently convex; geniculated area marked by a deep groove. Interarea short.

Interior of pedicle valve with subcircular to subflabellate muscle field ; diductor
scars large, semiflabellate ; teeth strong, dental plates thick and flaring; pedicle
callist small, apical. Entire visceral region tuberculate. Interior of brachial valve
with short, low, median ridge, somewhat thickened adductor field and tubercu-
late surface.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
THOIOEY De pana ates a ae 11.0 ? 20.3 23.0 ?
Paratype (117666).... 15.4 a of 19.6 20.3 ?
(117664a)... 10.4 ? 16.4 13.6 ?
a (CUN7 O07.) ere ony ve 13.1 20.5 24.0 ke

PART AT CHAZYAN AND RELATED BRACHIOPODS—COOPER 821

Types.—Holotype: 117669a; figured paratypes: 117664a, 117665, 1176606,
117667, 117668, 117669b, 117670a-c.

Horizon and locality—Oranda formation in Virginia: 0.6 mile northwest of
Linville Station, Broadway (15’) Quadrangle; 4 mile east of Strasburg, Stras-
burg (15’) Quadrangle; just west of the junction of Virginia Highways 617=
gio, and 777, + mile north of Green Mount Church, Broadway (15’) Quad-
rangle.

Martinsburg formation (part with Brongniartella=Salona) in Virginia: On
Virginia Highway 617=910, 0.15 mile north of Green Mount Church, $ mile
northwest of Linville Station, Broadway (15’) Quadrangle.

Martinsburg formation (Simwites bed) in Pennsylvania: 1 mile south of
St. Thomas, Mercersburg (15’) Quadrangle; Carlisle, Carlisle (15’) Quad-
rangle.

Rodman formation in Pennsylvania: At Bellefonte, Bellefonte (15’) Quad-
rangle.

Salona formation in Pennsylvania: At Salona, on Fishing Creek, Lock Haven
(15’) Quadrangle.

Rysedorf conglomerate in New York: Near Albany.

Carters formation in Alabama: 5 feet below the top of the limestone in the
quarry 0.3 mile north of Gate City, Birmingham Special (15’) Quadrangle.

Edinburg formation (Cyrtonotella zone just above the siltstone) in Virginia:
200 yards east of U. S. Highway 11, on Hiatt Run, 3 miles northeast of Win-
chester, Winchester (15’) Quadrangle.

Dark shale under Eureka quartzite in Nevada: Under 2 knobs of Eureka
quartzite, north side canyon, 3.1 miles N. 32° E. of Blair (Segura) Ranch,
Antelope Mountains, Roberts Mountains (1°) Quadrangle.

Discussion.—This species is characterized by the discontinuous character of
the concentric wrinkles, the swollen umbonal region of the pedicle valve, the
elevated rim around the place of geniculation, the nearly right-angled genicula-
tion and long trial. This species differs from the L. tenuistriata Sowerby identi-
fied by Foerste from the Saltillo formation in west Tennessee in having a differ-
ent outline, the Appalachian shells being more quadrate. The Saltillo shell does
not have the elevated rim at the place of geniculation nor the swollen umbonal
region. No other American species of true Leptaena are known to which this
species may be compared.

Leptaena ordovicica is a rare species in most localities of the Oranda forma-
tion. It is locally abundant, however, as at the Linville locality.

Two specimens from the Cyrtonotella zone near the base of the Edinburg
formation are referred to this species. These specimens are smaller than is usual
in the Oranda forms, but the essential specific characters of L. ordovicica are
present. These are the earliest specimens of true Leptaena yet found in North
America.

822 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

HESPERINIA Cooper, new genus
(Greek hespera, west)

Small, subrectangular shells with the hinge equal to or wider than the mid-
width; plano- to slightly concavo-convex; surface multicostellate. Foramen not
seen. Shell substance coarsely pseudopunctate.

Pedicle valve with long interarea, wide delthyrium covered by a pseudodel-
tidium. Teeth large; dental plates oblique, moderately long. Musculature not
known.

Brachial interior with moderately strong and erect cardinal process consisting
of 2 lobes and suggesting that of Leptaena. Brachiophores, flat blades, obliquely
situated on each side of the cardinal process and supported by shell substance
as in the Strophomenidae ; adductor field large ; subperipheral rim well developed
and channeled by pallial trunks.

Genotype-—Hesperima kirki Cooper, new species.

Discussion.—The external appearance of this little genus is very close to that
of Pomatotrema of the high Canadian Period. The interior details, however, are
totally unlike in the two genera because Pomatotrema has a simple cardinal
process whereas Hesperinia has a bilobed or leptaenoid cardinal process. Indeed,
this species suggests an early leptaenoid.

Affinities with Leptaena occur also in the configuration of the valves, the
pseudodeltidium, the subperipheral rim and cardinal process of the brachial valve
interior. The shells differ from Leptaena or Dactylogonia in interior details of
the brachial valves, Hesperimia lacking the adductor ridges, the thickened noto-
thyrial platform, and thick but short median ridge. These features also dis-
tinguish this genus from Goniotrema which is also a Pogonip genus.

HESPERINIA KIRKI Cooper, new species
Plate 213, E, figure 25; plate 2209, C, figures 9-15

Shells small, attaining a width of about 4 inch; subrectangular in outline;
sides gently rounded; anterior margin broadly rounded; cardinal extremities
nearly a right angle; hinge equal to the midwidth. Surface finely costellate, cos-
tellae numbering about 5 to the millimeter at the anterior margin.

Pedicle valve gently convex in lateral profile and with the maximum convexity
in the posterior two-thirds; anterior third somewhat abruptly bent toward the
brachial valve. Anterior profile broadly and fairly strongly convex. Umbonal
and median regions swollen; lateral slopes long and only moderately steep; an-
terior slope shorter and steeper than the lateral slopes. Interarea moderately
long, apsacline ; pseudodeltidium short, convex.

Brachial valve nearly flat in lateral and anterior profile; anterior margin
gently curved in the direction of the brachial valve. Interior with narrow margi-
nal thickening.

PART. I CHAZYAN AND RELATED BRACHIOPODS—COOPER 823

Measurements in mm.—
Brachial Hinge ,
Length length Midwidth width Thickness Height
HOlotypes iss. Hawes. 4 5.9 5.2 7.3 7.6 1.4? 1.8
Paratype, (117625). .... ? 73 10.7 10.6 ? ?

Types.—Holotype: 117626a; figured paratypes: 117625, 117626c, 1176274;
unfigured paratypes: 117626b,d, 117627b-f.

Horizon and locality—Tank Hill formation in Nevada: In the ridge just east
of Monument Canyon, Pioche (1°) Quadrangle; north end of the west side of
the Ely Spring Range, Highland (15’) Quadrangle.

Upper Pogonip group in Nevada: In White Pine Range, Hamilton.

Discussion—No other species of this genus is now known to which this one
can be compared.

TERATELASMA Cooper, new genus

(Greek teras, marvel; elasma, plate)

Shells small, attaining a length and width of about 4 inch; subquadrate in out-
line; gently biconvex in lateral profile; anterior commissure narrowly sulcate ;
surface finely multicostellate. Pseudopunctate.

Pedicle interior with short, stout flaring dental plates; diductor-adjustor scar
widely divergent, tear-shaped. Median region narrowly and deeply sulcate.

Brachial interior with wide and moderately deep notothyrial cavity ; cardinal
process bilobed ; sockets moderately deep, small, bounded by small, short brachio-
phores ; notothyrial cavity bounded on each side by a plate inclined to the valve
floor, lying just anterior to the brachiophore and extending to about the middle;
median septum club-shaped, originating just anterior to the middle of the noto-
thyrial cavity and extending to the front margin; median septum expanded and
elevated at its point of origin in the notothyrial cavity.

Genotype.—Teratelasma neumant Cooper, new species.

Discussion.—The interior details of this genus indicate a relationship to Dac-
tylogomia and the leptaenoids. The exterior is misleading because Teratelasma
suggests a finely costellate orthid rather than a leptaenoid. The relationship to
Dactylogoma is clear enough when the shell is examined in detail. Although
orthoid in appearance, the shell substance of Teratelasma is pseudopunctate.
Furthermore, the genus has a leptaenoid foramen which can be seen as a small
plug on the steinkern shown on plate 225, B, figures 5, 6, 7. Internally the rela-
tionship to Dactylogonia and the leptaenoids is clear in the presence of the bilobed
cardinal process which shows as two pits in figure 5 referred to above.

The interior details of this genus are as distinctive as the exterior characters,
especially in the brachial valve. The cardinalia are characterized by the bilobed
cardinal process which is small and delicate. The brachial processes are flat,
oblique blades on each side of the cardinal process. The adductor field is marked
by ridges similar to those in Dactylogonia but somewhat differently developed.
The posterolateral adductor ridge is small and not well formed. The inner 2
ridges are extravagantly developed and may appear as long hollow processes.
Figure 7 of plate 225, B, shows 2 holes slightly posterior to the middle that
represent the tubes. The tubular plates can also be seen in figures 10 and II.

824 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

The most striking feature of this peculiar genus is the median septum which
is unlike that of any other leptaenoid. This originates just inside the space be-
tween the anterior ends of the adductor blades and extends anteriorly nearly to
the front margin. At its posterior end the septum is stout and descends into the
adductor field as a sort of muscle platform. Anteriorly the septum is so strongly
elevated that it divides that part of the valve into 2 chambers. The trace of this
high-bladed septum can be seen on the pedicle side of the steinkern figured on
plate 225, B, figure 7. An impression of the blade is shown in figure 18 of the
same plate.

Teratelasma differs from Dactylogonia in its exterior form which is not leptae-
noid and in the arrangement of the adductor processes and the presence of the
high median septum.

TERATELASMA NEUMANI Cooper, new species
Plate 225, B, figures 5-23

Shell small, subquadrate in outline, with the hinge equal to the greatest width ;
cardinal extremities nearly a right angle; sides nearly straight; anterior margin
somewhat narrowly rounded; anterior commissure narrowly sulcate; surface
finely costellate, about 8 crowded in the space of I mm.

Pedicle valve nearly flat in lateral profile ; narrowly keeled medianly and with
the sides somewhat concave in anterior profile; umbo narrowly swollen, the
swelling continued anteriorly to form a narrow, subcarinate fold that extends to
the front margin; sides of fold steep; flanks bounding fold flattened to concave;
interarea moderately long, apsacline.

Brachial valve gently convex to nearly flat in lateral profile; anterior profile
broadly and very gently convex and with the median region narrowly depressed ;
sulcus originating at the umbo and extending to the front margin where it occu-
pies about one-quarter the width; flanks bounding sulcus gently convex.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Paratype (pedicle valve 117938f) ..... 6.8 i? 9.0 10.0 ? ?
oy (brachial valve 117938j).... ? 5.3 7.9? 8.6 ?

Types.—Holotype: 117938d; figured paratypes: 117938c,e-g,j,k,l-o,q; un-
figured paratypes: 117938a,b,h,i,p.

Horizon and locality.—Sevier formation (Benbolt equivalent) in Tennessee:
0.53 mile east-southeast of Old Kagley Church, Binfield (T.V.A. 139-NE)
Quadrangle.

Discussion—No other species of this genus is known to which this one
may be compared. The only known specimens are from the Sevier formation
at the Benbolt level.

DACTYLOGONIA Ulrich and Cooper, 1942
Dactylogoma Uxricu and Cooper, Journ. Paleont., vol. 16, No. 5, p. 623, 1942.

Shell of moderate size often attaining a little more than an inch in width, usu-
ally wider than long, with the hinge forming the widest part; lateral margins

PART. CHAZYAN AND RELATED BRACHIOPODS—COOPER 825

sloping inward, anterior margin broadly rounded. Concavo-convex in lateral
profile with both valves geniculated strongly in the direction of the brachial valve.
Surface finely costellate, usually without concentric wrinkles.

Pedicle valve with long palintrope, covered delthyrium, strongly convex
pseudodeltidium and apical foramen. Muscle field moderately large with fairly
long and wide diductor scars. Adjustor impressions present and adductors at-
tached to a low median elevation. Internal surface tuberculate.

Brachial valve with small cardinal process composed of 2 short-shafted pieces
with myophore surfaces each receiving a pair of muscles; median ridge low or
obsolete; brachial processes flat blades supported by the callus swelling of the
notothyrial and muscle regions ; adductor field fairly small, marked by 4 blade-
like plates arising from the floor, the smaller 2 between anterior and posterior
adductor scars and the larger 2 on the inside of the anterior scars. Line of genicu-
lation marked by a low, thickened ridge; entire inner surface tuberculate.

Genotype-—Dactylogomia geniculata Ulrich and Cooper, Journ. Paleont.,
vol. 16, No. 5, p. 624, pl. go, figs. 19-23, 1942.

Discussion.—Dactylogonia differs from Leptaena in the absence of concentric
wrinkles in the visceral portion, but more importantly in the presence in the
brachial valve of the bladelike ridges arising from the floor between the muscle
scars and in the small median ridge. Members of this genus occur in the Chazy
(Crown Point and Valcour) formations of New York and in several formations
of the Southern Appalachians of Tennessee and Virginia, and in the Bromide
formation of Oklahoma.

DACTYLOGONIA ALTERNATA Cooper, new species

Plate 218, D, figures 11-14; plate 218, G, figures 22-30

Shell of about medium size for the genus, wider than long and with the hinge
forming the widest part ; sides gently rounded; anterior margin broadly rounded;
geniculation taking place about 8 mm. anterior to the beak; angle of geniculation
about 100°. Surface marked by fine and coarse costellae, about 5 or 6 of the
former occupying a space of 5 mm. at the front margin and up to 7 fine costellae
between the stronger ones.

Pedicle valve with visceral region flat to slightly concave in lateral profile;
geniculated part narrowly rounded; trail short and gently convex in profile;
foramen moderately large; interarea long; pseudodeltidium large.

Brachial valve with visceral part nearly flat to faintly convex; trail short and
fairly abruptly bent.

Measurements in mm.—

Brachial Mid- Hinge Thick- Surface pie en
Length length width width ness length trail
PA GIOCY Fes gac\ arash, idaiete 11.8 10.0 15.4 13.5+ 4.6 16.0 7.0
Paratype (117581a).... 12.5 ? 075 18.0 ? 16.0 7.0
(117581b).... 10.3 8.8 14.0 14.0 2.2 EES 3.0

a (117581e).... 10.6 90.5 16.4 16.9 4.1 14.0+ 5.0-+

826 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 11758ic; figured paratypes: 117581a,b,d,e, 117582a,b.

Horizon and locality—Lenoir formation (reefy calcarenite beds under the
Mosheim limestone) in Tennessee: On the southwest side of the cemetery be-
hind the Friends Church, northwest edge of Friendsville, Concord (T.V.A.
138-SW) Quadrangle.

Lenoir formation (granular beds above the Mosheim limestone) in Tennessee:
At Bluff City, Bluff City (T.V.A. 198-NE) Quadrangle; south of Friends
Church, northwest side of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Tumbez formation in Virginia: In a small quarry on the south side of U. S.
Highway 11, 3 miles southwest of Marion, Marion (T.V.A. 218-SE) Quad-
rangle.

Discussion—This species has generally been mistaken in the Southern Appa-
lachians for D. incrassata (Hall). It is characterized by fairly large size for the
genus and fairly strong geniculation. This species differs from D. incrassata in
having a much larger size, in having a longer visceral disk region, somewhat
less strong geniculation and a shorter trail. It differs strongly from D. genicu-
lata in having a less rectangular outline, stronger costellae, and a less strongly
geniculated trail.

DACTYLOGONIA CONCENTRICA Cooper, new species
Plate 216, B, figures 5-7

Small, semielliptical in outline, hinge about equal in width to the width of the
valve at the middle; cardinal extremities approximately a right angle; sides
gently rounded; anterior margin broadly rounded. Surface marked by about
II prominent thin, rounded costellae separating groups of very fine elevated cos-
tellae that are crossed by fine elevated concentric lines of about the same strength
as the fine costellae producing a beaded effect. Ornamentation of brachial valve
showing a slightly stronger development of the concentric lines.

Body of pedicle valve gently convex in lateral profile and very gently convex
in anterior profile; geniculation of the pedicle valve taking place slightly less
than 8 mm. anterior to the beak; angle of geniculation about 100°. Geniculated
area short. Palintrope broad; interarea long and flat; pseudodeltidium strongly
convex. Apical foramen small.

Brachial valve gently concave with the greatest concavity appearing as a pit
just anterior to the umbo. Anterior geniculation slight, resulting in a valve of
nearly uniformly gentle concavity. When the shell is moistened the sutures of
the adductor plates with the floor of the valve are visible.

Measurements in mm.—Holotype, length 8.5, surface length 10, body length 8,
length of gen. area 2, width 11.7, hinge width 11, thickness 3.6.

Type.—Holotype: 117583.

Horizon and locality Lincolnshire formation (Hogskin member) in Ten-
nessee: 2 miles northeast of Hall Crossroad, Fountain City (T.V.A. 146-SW)
Quadrangle.

Discussion.—This is a small species characterized by subrectangular outline,

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 827

flattish brachial valve and subdued ornamentation in which the concentric fila
are prominent. It is not quite like any other species so far described. It differs
from D. geniculata in the strength of the concentric elements of the ornamenta-
tion, the gentle convexity of the pedicle valve, and the short trail.

DACTYLOGONIA EXTENSA Cooper, new species
Plate 210, B, figures 2-5

Lepiaena incrassata TWENHOFEL and Wuittnc (not Hall), Geol. Soc. Amer. Special Pap. 11,
p. 50, pl. 7, figs. 17, 18, 1938.

Shell of about medium size for the genus, with the widest part slightly anterior
to the hinge; lateral margins sloping inward strongly ; anterior margin broadly
rounded; ornamentation consisting of groups of 5 to 7 fine costellae bounded
by stronger costellae.

Pedicle valve with posterior half of shell concave to flat in lateral profile, the
concavity located just anterior to the umbo; flanks of posterior half slightly con-
cave but rising to the place of geniculation about 7.5 mm. anterior to the beak.
Angle of geniculation variable; geniculated portion long and convex, most con-
vex at and just anterior to point of flexure; length of geniculate portion greater
than the length of the body part of the shell. Anterior slope steep, decreasing
posterolaterally to the cardinal extremities where it becomes considerably flat-
tened. Palintrope unusually long, apsacline.

Brachial valve with slightly convex body part and abruptly bent geniculated
portion.

Measurements in mm.—Holotype, length 13, width 19, hinge width 18, sur-
face length 18, body part surface length 7.5, surface length of trail 10.5.

Types.—Holotype: 117584b; figured paratype: 117584a.

Horizon and locality—Mingan formation (lower third), Bald Island, Mingan
Group, St. Lawrence River.

Discussion.—This species is characterized by its long trail and the rounded
area of geniculation. It is most like some extreme examples of D. incrassata but
the angle of geniculation is greater and the trail longer. The Mingan form does
not have the geniculated part so narrowly rounded even though tangents to the
visceral region and the trail intersect in an acute angle. The angle is about 75°
in D. extensa but only 55° in D. incrassata, The interarea of D. extensa is much
longer and the pseudodeltidium larger than in D. incrassata which has only a
short interarea.

DACTYLOGONIA GENICULATA Ulrich and Cooper
Plate 216, D, figures 14-30; plate 217, M, figures 38, 39; plate 218, B, figures 4-7;
plate 219, E, figure 11; plate 219, F, figures 12, 13
Dactylogonia geniculata ULRicH and Cooper, Journ. Paleont., vol. 16, No. 5, p. 624, pl. 90,
figs. 19-23, 1942.
Shell wider than long with acute cardinal extremities ; profile concavo-convex ;
lateral margins sloping medially ; anterior margin broadly convex to subtruncate.

828 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Surface covered by closely crowded costellae of unequal size, 5 to 9 of the smaller
costellae arranged into groups by the scattered larger ones.

Pedicle valve with the posterior 9 mm. nearly flat but the anterior narrowly
convex; geniculation takes place at about 9 mm. anterior to the beak and the
angle of geniculation is about 95°. Beak erect, the umbo inconspicuous but
slightly swollen. Geniculated part narrowly convex; front slope slightly convex
in profile and steep.

Umbo of brachial valve forming a round hollow anterior to the beak ; body of
valve slightly concave but flattened somewhat at the cardinal extremities. Genicu-
lated part fitting closely against the trail of the pedicle valve and having practi-
cally the same contour as that valve.

Interior of pedicle valve with muscle field not quite extending to the middle,
moderately impressed; adductor ridge low. Brachial valve with short median
septum situated between the lobes of the cardinal process; adductor blades
strongly developed ; ridge at front of visceral area slightly elevated, moderately
thick.

Measurements in mm.—

Brachial Hinge Thick- Surface
Length length Midwidth width ness length
Holetype” ss: sc. s eee II.I 0.8 15.0 16+ 3.0 15.0
Paratype (108202e)... 10.2 9.8 14.7 16-+ 2.9 14.5
o (108202f) ... I1.1 10.2 15.8 ? 23 14.0

Types——Holotype: 108202a; paratypes: 108202b-g; figured hypotypes:
117585b,c,f,h, 117586a, 117587, 117588a.

Horizon and locality.—Arline formation in Tennessee: Along old wagon road
in glade, 4 mile southeast of Friendsville, Concord (T.V.A. 138-SW) Quad-
rangle; 4 mile south of McMullens, Meadow (T.V.A. 139-NW) Quadrangle.

Arline formation in Virginia: Porterfield Quarry, 5 miles east of Saltville,
Maccrady (T.V.A. 218-NW) Quadrangle.

Little Oak formation in Alabama: Junction of Bailey Gap and main roads,
1} miles northeast of Newhope Church, Cahaba Valley, SW4SW4 sec. 13,
T. 19 S., R. 2 W., Vandiver (15’) Quadrangle.

Discussion.—This species can be recognized by the similarity of its outline and
profile to examples of Leptaena. The outline is nearly rectangular and the an-
terior geniculation is abrupt. No other described species except D. prona and
D., transversa, is quite like it in these respects. D. prona (Willard) is suggestive
but that species is much larger and the trail is marked by a distinct sulcus.
Dactylogonia transversa is strongly rectangular in outline and is abruptly genicu-
late, but it is a larger and proportionately wider shell than D. geniculata.

DACTYLOGONIA INCRASSATA (Hall)

Plate 219, I, figures 16-23; plate 210, J, figures 24-27; plate 220, B, figures 6-8;
plate 226, C, figures 5-9

Leptaena incrassata HALL, Pal. New York, vol. 1, p. 19, pl. 4 bis, figs. 2a-d, 1847—-RAYMOND,
Ann. Carnegie Mus., vol. 7, No. 2, p. 230, pl. 34, figs. 32-37, IOII.

Shell fairly large for the genus, wider than long, with the hinge width almost
twice the length ; cardinal extremities alate; strongly geniculate; angle of genicu-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 829

lation variable; surface marked by strong and fine costellae, about 5 of the
latter in 5 mm. at the front margin and about 7 fine costellae separating the
larger ones. Fine costellae strongly cancellated by fine concentric lines.

Pedicle valve with variable lateral profile, the visceral portion varying from
flat to gently convex, the geniculated part from narrowly convex. Trail nearly
flat to gently convex and varying in angle of geniculation from 60° to 100°.
Geniculation occurring 6 or 7 mm. anterior to the beak. Geniculated part nar-
rowly to roundly convex depending on angle of geniculation. Umbonal and
median regions somewhat swollen; flanks of visceral part somewhat depressed.
Interarea moderately long; pseudodeltidium large and convex.

Brachial valve with visceral part gently concave, with the median region the
deepest part and the flanks somewhat flattened. Trail moderately long, slightly
concave ; adductor plates strongly developed.

Measurements in mm.—

Brachial Mid- Hinge Thick- Surface ‘Trail
Length length width width ness. length length

Hypotype (117580a)..........-. 10.8 8.8 16.4 15.6+ 4.1 18.0 9.0
4 (GREZE OU) sia hesentve eocege' 10.8 9.1 14.6 ? 4.2 16.0 8.0
rk (Carnegie Mus. 5446). 11.7 ? 16.0 21.7 iP 15.0 7.0

Types.—Figured hypotypes: Carnegie Mus. 5446; A.M.N.H. 25049/1,2,3;
U.S.N.M. 117589a-c, 117590a, 117593a,b.

Horizon and locality—Crown Point formation in New York: At Sloop Bay,
Valcour Island, Lake Champlain, Plattsburg (15’) Quadrangle.

Same formation in Vermont: On Isle La Motte, Rouses Point (15’) Quad-
rangle ; on a small peninsula of the west shore of Providence Island, Plattsburg
(15’) Quadrangle; Fort Cassin, Port Henry (15’) Quadrangle.

Discussion.—This species is without doubt a fairly variable one, but in spite
of that it does not seem to occur in the Southern Appalachians. Dactylogonia
alternata has been mistaken for it but that species is larger and less strongly
geniculated. Dactylogomia incrassata has been confused on Mingan Island with
a somewhat more robust form having a more elongate interarea and longer trail.
The two species of Dactylogonia now known from Oklahoma are quite unlike
D. incrassata because they are only slightly geniculated. Dactylogonia marmorata
is suggestive but that species has fairly prominent wrinkles which distinguish
it at once from the New York species.

DACTYLOGONIA MAGNA Cooper, new species
Plate 194, E, figures 28-30; plate 220, C, figures 9-17

Shell large for the genus, slightly wider than long with the hinge not quite
equal to the shell width at the middle; sides and anterior margin gently rounded ;
point of geniculation about 12 mm. anterior to the beak; angle of geniculation
about 95°. Ornamentation consisting of a few strong costellae in a field of finer
ones ; 3 strong costellae to 5 mm. at the front margin; strong costellae separated
by as many as 10 of the finer kind; fine costellae cancellated by fine concentric
lines. Posterior margin with short vertical wrinkles.

830 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve roundly angulated at about the middle in lateral profile ; posterior
or visceral portion nearly flat in lateral profile; geniculate portion somewhat
broadly rounded; trail long and gently convex in profile. Umbo somewhat nar-
rowly rounded; median portion of visceral region convex but flanks somewhat
depressed. Posterior margin irregularly wrinkled. Interarea long; pseudodel-
tidium thick and convex. Muscle area small.

Brachial valve deeply concave, most concave in the median region where the
valve geniculates; umbo and median region of the visceral part sulcate; flanks
bounding sulcus flattened. Posterior margin wrinkled.

Measurements in mm.—Holotype, length 21.0, brachial length 18.3, midwidth
24.9, hinge width ?, thickness 3.1, surface length 28.0, trail length 14.0.

Types.—Holotype: 1175914; figured paratypes: 117591b,d, 117592; unfigured
paratypes: I1759QIc.

Horizon and locality.—Lincolnshire formation (Hogskin member) in Ten-
nessee: 0.4 mile east-northeast of Red Hill, 4 miles west-southwest of Thorn
Hill, Avondale (T.V.A. 162-SW) Quadrangle; Sally Cleveland Farm, # mile
southwest of Washburn, Dutch Valley (T.V.A. 154-SW) Quadrangle.

Discussion.—Dactylogonia magna is an unusually large species for this genus
which, besides its size, is characterized by an unsually long trail and a nearly
square outline. It can only be compared to the larger species of the genus such
as D. obsoleta (Butts) and D. obtusa. It differs from the former in larger size,
square outline, longer trail, and more deeply concave brachial valve. From the
latter it differs in its larger size, square outline, and the long, rounded trail.

DACTYLOGONIA MAGNIFICA Cooper, new species
Plate 225, A figures 1-4

Shell of about medium size for the genus, thin shelled, generally wider than
long and with the hinge forming the widest part; cardinal extremities acute;
sides sloping obliquely toward the middle. Surface marked by strong costellae,
2 or 3 in 5 mm. at the front which separate bands of closely crowded and beauti-
fully cancellated costellae; fine costellae numbering about 7 to the millimeter at
the front margin.

Pedicle valve very gently convex in lateral profile but somewhat angulated in
the front fifth; anterior profile broadly and gently convex and somewhat cari-
nated in the middle; umbonal region slightly inflated, the swelling continued an-
teriorly to the place of geniculation at the front as a low but poorly defined fold ;
lateral slopes long and sloping gently to the sides. Foramen large, encroaching
on the umbo; interior with large and flabellate muscle area.

Brachial valve nearly flat to gently concave in profile and the anterior quarter
bent in the direction of the brachial valve at a broad angle. Umbonal region
sulcate. Interior with strongly developed and closely crowded adductor ridges.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (pedicle valve) .......... 8.5 ? 11.4 12.9 >

Paratype (brachial valve 117942c).. ? 8.7 12.0 12.8 ?

PART 5 CHAZYAN AND RELATED BRACHIOPODS—COOPER 831

Types.—Holotype: 117942a; figured paratypes: 117942c,d; unfigured para-
type: 117942b.

Horizon and locality—Lower Ward Cove formation in Tennessee: 3 mile
southwest of Mount Eager Church, Hogskin Valley, Powder Springs (T.V.A.
154-SW) Quadrangle.

Discussion—This species is characterized by its angular lateral extremities,
short geniculated area and distant costellae in a mat of fine cancellated costellae.
This species is most like D. incrassata (Hall) of the New York Chazyan but is
more distantly and more delicately ornamented. It is less strongly geniculated
and less square in the cardinal extremities than D. geniculata, and differently
ornamented.

DACTYLOGONIA MARMORATA Cooper, new species
Plate 217, F, figures 11-15

Shell small for the genus, wider than long and with the hinge forming the
widest part; sides gently rounded; anterior margin broadly rounded. Surface
marked by a mat of fine costellae cancellated by fine concentric lines ; a few larger
costellae 5 or 6 in number are present. More or less prominent concentric
wrinkles mark the visceral region.

Pedicle valve with visceral region extending for 5 to 7 mm. from the beak,
gently convex in lateral profile ; angle of geniculation variable, usually near 95° ;
trail variable, usually fairly long and steep.

Visceral region of brachial valve gently concave; umbo concave; deepest at
place of geniculation ; trail not so long as that of the pedicle valve.

Measurements in mm.—

Brachial ‘ Hinge Thick- Surface Trail
Length length #Midwidth width ness length length

Holotype“). 810. fis es 8.9 ? 11.8 12.9 ? 0.5 1.5
Paratype (123265a)... 6.9 ? 10.6 12.1 ? 7.5 2.0
" 123 2650)iiee) con 8.7 igs 16.7 ? 10.0 2.0
* (123265d)... 8.4 ? 11.9 12.7 ? 11.0 3.0

Types.—Holotype: 123265); figured paratypes: 123265a,c,d; unfigured para-
type: 123265e.

Horizon and locality—Murat formation in Virginia: 2 miles northwest of
Lexington, Lexington (15’) Quadrangle.

Discussion.—This is a species of moderate size somewhat resembling D. in-
crassata or D., extensa in form. It differs from both of them in having moder-
ately strong but irregular wrinkles on the visceral disk area. Dactylogonia palus-
tris is also a somewhat wrinkled form but differs in its smaller size, more regular
outline, shorter trail, and smaller visceral disk region.

DACTYLOGONIA OBSOLETA (Butts)
Plate 217, K, figures 32-34
Rafinesquina obsoleta Butrs, Alabama Geol. Surv., Special Rep. 14, pl. 26, figs. 20, 30, 1926.

Only two specimens of this species are known that preserve the outline and
profile of the shell. As both are coarsely silicified, description of details of the

832 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

exterior will have to await the discovery of more favorably preserved specimens.
Information on the interior is also lacking except for the cardinal process. The
holotype is large for the genus, with the hinge forming the widest part and the
lateral margins sloping gently toward the middle. The anterior margin is broadly
rounded. The surface shows distant costellae and faint traces of finer ones be-
tween the larger ones.

The pedicle valve is strongly convex with the greatest convexity located
slightly anterior to the middle; inasmuch as the body of the shell is not clearly
marked from the geniculated portion by an abrupt change of curvature, it is
difficult to place the position of geniculation, but it appears to be about 8 to
IO mm. anterior to the beak. The body of the shell is gently convex in profile
and has a slightly swollen umbonal region. The anterior sloping part or trail is
moderately steep, with the steepest parts toward the anterolateral extremities.
Angle of geniculation 120°. Interarea short, apsacline.

The brachial valve is strongly geniculated at an angle of about 130° about
10 mm. anterior to the beak; the deflected part is steep and makes a rim about
6 mm. wide around the body of the shell which is flat to slightly concave.

Measurements in mm.—Holotype, length 18.3, brachial length 13.2, width 23.8,
hinge width 22.7, thickness 5.0, surface length 22.5.

Type—Holotype: 71505.

Horizon and locality—Little Oak formation in Alabama: 4 mile north of Pel-
ham, Bessemer Iron District (15’) Quadrangle; junction Bailey Gap and Cahaba
Valley roads, 1% miles northeast of Newhope Church, SW4SW34 sec. 13,
T. 19 S., R. 2 W., Vandiver (15’) Quadrangle.

Discussion.—This species is characterized by large size, wide hinge, strong
convexity of the pedicle valve, and gentle concavity of the brachial valve. This
species suggests D. obtusa but differs in angle of geniculation and is larger, less
deep, and with more oblique sides.

DACTYLOGONIA OBTUSA Cooper, new species
Plate 216, C, figures 8-13; plate 217, L, figures 35-37; plate 220, A, figures I-5

Shell large, variable, wider than long with the hinge forming the widest part;
lateral margins sloping moderately toward the middle or slightly rounded; an-
terior margin broadly rounded. Surface costellate, costellae rounded and sepa-
rated by spaces narrower than the costellae; on the pedicle valve costellae alter-
nate in size, I or 2 smaller ones alternating with the larger ones, but on the
brachial valve the costellae are more uniform in appearance and more crowded
with less differentiation between the larger and smaller ones.

Pedicle valve geniculating about 11 mm. anterior to the beak; angle of genicu-
lation obtuse, about 95 to 100°; visceral portion moderately convex, umbo and
beak slightly swollen ; a low, indistinct median fold extends anteriorly for about
a quarter the length but in some specimens is distinguishable for the length of
the body of the shell. Median part of shell body slightly swollen with gentle
slopes to the margins. Geniculated part or trail convex in profile, and with steep-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 833

est slopes at the anterior. Palintrope and pseudodeltidium short ; apical foramen
smaller than usual in the genus.

Brachial valve fitting closely into the pedicle valve and with concave umbonal
region ; valve flattened slightly in the vicinity of the cardinal extremities. Most
concave in the midregion, less so laterally of the middle.

Pedicle valve with small wide teeth that have deep fossettes, dental plates
nearly obsolete; muscle area slightly wider than long ; diductor scars large, ad-
ductor field narrowly elliptical, periphery of muscle field slightly thickened and
surrounding shell surface tuberculate.

Brachial valve with notothyrial platform thickened and bearing 2 short shafted
processes with flattened myophore surfaces. Brachial processes flat, short, sup-
ported by the notothyrial platform. Median ridge nearly obsolete. Posterior
adductor scars the larger; anterior adductor processes long and convex inward.
Entire inner surface of visceral portion strongly tuberculate.

Measurements in mm.—

Brachial Hinge Surface
Length length Width width Thickness length
ET OIGHUIE s faheisyn ss orete's 16.5 14.5 18.3 18 + 3.4 20.5
Paratype (117595).. 17.9 13.8 22.2 20.6 4.8 22+

Types.—Holotype: 1175941; figured paratypes: 117594c,d,h, 117595, 117596;
unfigured paratypes: 117594a,b,e-g.

Horizon and locality Lincolnshire formation (2-foot layer on marble) in
Tennessee: In Clinch Valley at Shiloh Church, near center of the northwest
subquad. of Pressmans Home (T.V.A. 171-NE) Quadrangle.

Same formation in Virginia: At Marcem Quarry, 2 miles west of Gate City,
Gate City (T.V.A. 188-NE) Quadrangle.

Arline formation in Virginia: In Porterfield Quarry, 5 miles east of Saltville,
Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This species is a moderately large one characterized by a subrec-
tangular to subquadrate outline, gently convex visceral region, moderately strong
geniculation, and moderately deep brachial valve. It differs from D. obtusa in
not having a wide hinge, in the more narrowly rounded anterior, the less deep
brachial valve, and a less obtuse angle of geniculation. It differs from D. prona
which also occurs in the Lincolnshire formation in its less abrupt geniculation
and the longer and more gently inclined trail.

DACTYLOGONIA PALUSTRIS (Willard)

Leptaena palustris WiLtLarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 278,
pl. 3, fig. 14, 1928.

Type.—Holotype: M.C.Z. 86109.

Horizon and locality.—Holston limestone= Farragut formation in Tennessee:
At Concord, Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—This is a small species characterized by fairly regular form, mod-
erate geniculation, and a moderately but irregularly wrinkled visceral region. No
specimens in the National Collection can be identified with this species.

834 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

DACTYLOGONIA PARVA Cooper, new species
Plate 218, A, figures 1-3

Small for the genus, subtrapezoidal in outline and with the hinge forming the
widest part. Sides gently rounded and oblique ; anterior margin broadly rounded ;
surface marked by strong and fine costellae, the former not well developed ; con-
centric wavy lines cancellate the fine costellae and generally dominate the orna-
mentation. Visceral region marked by discontinuous concentric wrinkles espe-
cially near the place of geniculation.

Pedicle valve geniculating about 5 mm. anterior to the beak; angle of genicu-
lation abrupt, approximately go°. Visceral region marked by a poorly defined,
low median fold; flanks bounding fold concave; anterior of visceral region
marked by a more or less prominent concentric fold. Trail long, gently convex
in lateral profile.

Brachial valve with visceral region gently concave; umbonal region concave}
lateral areas of visceral region somewhat flattened. Trail abruptly geniculated.

Measurements in mm.—

Brachial Hinge Surface Trail
Length length Midwidth width Thickness length length
Holdoty pers. «setae 6.6 ? 8.1 9.6 ? 8.5 4.5
Paratype (117597c). 6.5 5.2 8.7 9.8 1.6 7.5 2.0-+

Types——Holotype: 117597a; unfigured paratypes: 117597b-e.

Horizon and locality—tLincolnshire formation (Hogskin member-Oligo-
rhynchia bed) in Tennessee: 0.4 mile east-northeast of Red Hill, 4 miles west-
southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle.

Discussion—This species is characterized by its small size, wrinkled visceral
region, and long, abruptly geniculated trail. Part of this characterization immedi-
ately suggests D. palustris, but that species is a larger one, with a shorter and
less strongly geniculated trail.

DACTYLOGONIA PRONA (Willard)

Leptaena prona Wirarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 270,
pl. 3, figs. 15, 16, 1928.

Type—Holotype: M.C.Z. 8620.

Horizon and locality.—Lincolnshire formation (Dinorthis atavoides zone) in
Virginia: Near Goodwins Ferry on New River, Giles County.

Discussion.—The specimen on which this species is based is a very imperfect
one with one side missing. Dimensions in millimeters based on the half dimen-
sion are; length 14.3, midwidth 18.2, hinge width 25.8, surface length about 20,
length of trail about 7.0. The angle of geniculation is about 95°. The species is
thus a fairly large one having a moderately but sharply bent trail. The antero-
median region of the trail is somewhat concave, in this respect resembling
D, transversa. It differs, however, in much larger size and more sharply genicu-
lated trail. Its very sharply geniculated anterior also distinguishes it from
D. obsoleta, another Lincolnshire species.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 835

DACTYLOGONIA SCULPTURATA Cooper, new species
Plate 218, F, figures 17-21; plate 219, D, figure 10

Shell large for the genus, wider than long and with the hinge forming the
widest part; sides slightly rounded and slightly oblique ; anterior margin broadly
rounded. Surface marked by strong and fine costellae, the latter exquisitely can-
cellated by fine concentric lines; 5 or 6 of the stronger costellae occupy 5 mm.
at the front margin; 5 or 6 of the fine costellae fill the spaces between the strong
costellae.

Pedicle valve fairly evenly and moderately convex in lateral profile and with
no pronounced place of geniculation; anterior profile broadly and moderately
convex. Umbonal and median regions somewhat swollen; lateral slopes long and
moderately steep. Interarea long.

Brachial valve moderately and broadly concave with the maximum concavity
in the median region ; umbo sulcate; lateral areas somewhat flattened.

Measurements in mm.—Holotype, length 16.2, brachial length 14.1, midwidth
21.8, hinge width 22.5, thickness 3.8, surface length 18.0.

Types.—Holotype: 117598a; figured paratype: 117598b.

Horizon and locality —Bromide formation (Mountain Lake member) in Okla-
homa: On the McLish Ranch, sec. 24, T. 1 S., R. 7 E., Johnston County ; 2,300
feet south and 2,000 feet west of the northeast corner sec. 36, T. 1 S., R. 7 E.,
Johnston County; Baptist grounds along Falls Creek, SWA4NW4SW3 sec. 33,
T.1S., R. 2 E., Murray County.

Discussion.—This species is characterized by large size and the regularity and
beauty of its sculpture. Its larger size suggests comparison with D. obsoleta
(Butts), but that species is more strongly convex and more strongly geniculated.

DACTYLOGONIA STRASBURGENSIS, Cooper, new species
Plate 186, E, figures 15-19

Shell large for the genus, length and width nearly equal; sides rounded; an-
terior margin strongly rounded; surface marked by fine, distant strong radii
numbering about 4 in 5 mm. at the front margin. Spaces between strong costellae
marked by 4 or 5 fine costellae which are cancellated by fine concentric lines.

Pedicle valve with unevenly convex lateral profile, the posterior half some-
what flattened but the anterior half moderately convex. Anterior profile mod-
erately domed; umbo narrowly convex, the convexity forming a low and short
fold that disappears posterior to the middle; flanks bounding fold flattened to
gently concave.

Brachial valve having a shallow concavity with the maximum depth just an-
terior to the middle; visceral region gently concave to nearly flat. Interior with
short and delicate cardinalia.

Measurements in mm.—

Brachial Hinge Thick- Surface

Length length Midwidth width ness length

EV GIOUV BO oo .n sit td cians 19.1 ‘q 21.2 21.2 ? 23.0
Paratype (117600a). 24.7 ? 23.5 22.8 > 30.5

x (117600b) . ? 17.1 24.0 ? 28.4 ? 19.5

836 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 117600c; figured paratypes: 117599a, 117600a; unfigured
paratypes: 117599b, 117600b,d.

Horizon and locality—Edinburg formation (Cyrtonotella zone) in Virginia:
In ravine opposite switch, § mile east of Strasburg Junction, Strasburg (15’)
Quadrangle.

Discussion.—This is a large species characterized by considerable depth by
virtue of a long trail. The visceral area is short, but the trail is exceptionally
long and the sculpturing prominent. The species approaches D. magna in size
and depth but differs in sculpture.

DACTYLOGONIA SUBAEQUICOSTELLATA Cooper, new species
Plate 217, J, figures 27-31; plate 2109, A, figure 1; plate 219, C, figures 6-9

Shell about medium size to small for the genus, with the hinge narrower than
the greatest shell width which is just anterior to the hinge. Lateral margins
sloping gently toward the middle; anterior margin broadly rounded. Surface
marked by narrow, elevated, rounded costellae of nearly equal size, spaced about
17 in 5 mm. at the front.

Pedicle valve gently convex, with the greatest convexity in the anterior half;
flexed portion not prominent, point of flexure about 7 mm. anterior to the beak;
umbonal region slightly swollen, the fullness continued anteriorly to the middle;
on each side of this median elevation the valve is slightly flattened or sunken to
the margins. Palintrope long, interarea flat, apsacline.

Brachial valve with point of flexure 6 mm. anterior to the beak and at this
point having its greatest concavity. The point of flexure on this valve is stronger
than that on the pedicle valve; median region somewhat more concave than the
surrounding areas and the region about the cardinal extremities flattened. Palin-
trope unusually long and flat. Brachial interior with prominent adductor plates
and small cardinal process.

Measurements in mm.—Holotype, length 10, midwidth 12.9, hinge width 11.4,
surface length 11, brachial valve length 8, thickness 2.2.

Types—Holotype: 117602; figured paratypes: 117601b,c, 117603; unfigured
paratype: 117601a.

Horizon and locality—lLower Bromide (Mountain Lake member) in Okla-
homa: McLish Ranch, sec. 24, T. 1 S., R. 7 E.; 2 miles southeast of McLish
Ranch, 3 miles northwest of Bromide, Johnston County ; between Sylvan and Mill
Creeks on west branch of Sycamore Creek, sec. 27, T. 3 S., R. 4 E., Carter
County.

Discussion.—This is a small and moderately concave species with fairly strong
and crowded costellae. Its general form is like that of D. sculpturata but the
size and general appearance suggest D. concentrica, which species, however, is
flatter, somewhat smaller, and less strongly ornamentated.

DACTYLOGONIA TRANSVERSA Cooper, new species
Plate 217, C, figures 4, 5

Shell considerably wider than long, with the hinge forming the widest part;
sides short and slightly oblique ; anterior margin somewhat truncated to emargi-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 837

nate; ornamentation obscure because of poor preservation but of the usual type
in the genus, consisting of a mat of fine costellae separated into groups by stronger
ones.

Pedicle valve unevenly convex in lateral profile; the visceral or posterior part
very slightly convex; trail moderately long; angle of geniculation about 100°.
Geniculation occurring about 9 mm. anterior to the beak. Umbonal region
slightly convex but most of visceral area flattened; trail slopes steep. Muscles
deeply inserted.

Brachial valve with visceral region nearly flat, umbo concave, and anterior
sharply geniculated toward the brachial valve ; deepest part at place of genicula-
tion. Interior with strongly developed ridge at the place of geniculation ; adduc-
tor blades well developed.

Measurements in mm.—

Brachial Hinge Thick- Surface Trail
Length length Midwidth width ness length length

Holotype ....... 12.6 11.3 22.9 23.0-+- ? ? 7.0+
Batatype «kets fs 14.7 ? 21.0 23.6 Fy 20.0 10.0

Types.—Holotype: 117604b; unfigured paratype: 117604a.

Horizon and locality— Botetourt formation in Virginia: Between U. S. High-
way 60 and Whistle Creek from 1 to 2} miles northwest of Lexington, Lexington
(15’) Quadrangle.

Discussion.—This species is characterized by its steep trail and transversely
rectangular outline. Its form is like D. geniculaia, but it is larger and more trans-
verse. Its resemblance to D. prona is strong, but comparison with that species
is difficult because details of the brachial valve are unknown. Nevertheless,
D. prona appears to be a much less transverse species than the Botetourt form.

DACTYLOGONIA sp. 1
Plate 228, C, figure 19

The material of this species consists of a poorly preserved and incomplete
adult and an interior of the pedicle valve. The species was large, having a
visceral area extending 13 mm. anterior to the beak. The trail is mostly missing.
The interarea is short, and the specimen is quite thin. Thus the species was
large and thin bodied.

The pedicle interior indicates short but flaring dental plates with short and
narrow umbonal cavities. The muscle field is moderately large and subcircular
in outline; the diductors are flabellate ; the adductor scars are somewhat elongate
and separated anteriorly by a low ridge. The remainder of the interior is sparsely
papillose.

Figured specimen.—117605.

Horizon and locality—Benbolt formation in Virginia: 4 mile north of the
school at Rye Cove, Clinchport (T.V.A. 188-NW) Quadrangle.

Same formation in Tennessee: About 0.1 to 0.2 mile north of the road, 1.4 miles
northeast of Lee Valley, Pressmens Home (T.V.A. 171-NE) Quadrangle.

838 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

DACTYLOGONIA sp. 2
Plate 219, H, figure 15

Two specimens were taken from the rotted Botetourt material at the junction
of Virginia Highways 731 and 724 about 2 miles northwest of Brownsburg,
Lexington (15’) Quadrangle. These specimens show the muscle field to per-
fection. No dental plates are preserved in either specimen. The diductor scars
are elongate and somewhat tear shaped. The adjustor scars appear outside the
diductors. They are shorter than the diductors and are also tear shaped. The
diductor scars extended directly anteriorly. The adductor scars are small and
narrowly elongate and separated by a slight median ridge.

Figured specimen.—117607A.

DACTYLOGONIA sp. 3
Plate 217, E, figures 8-10

This small Dactylogonia is most suggestive of D. parva but differs in having a
shorter trail and a somewhat less geniculated anterior and in not having the
prominent ridge at the place of geniculation. This may be the young of some
larger species, but the early geniculation suggests a small adult.

Figured specimen.—117608.

Horizon and locality.—Benbolt formation in Virginia: West of Rye Cove,
Clinchport (T.V.A. 188-NW) Quadrangle.

DACTYLOGONIA sp. 4
Plate 194, D, figures 23-27

Small, wider than long. Pedicle valve with visceral region gently convex in
lateral profile and with an angle of geniculation of about 115°. Point of genicu-
lation about 6 mm. anterior to the beak. Trail rounded, short. Surface marked
by prominent, somewhat irregular concentric lines cancellated by fine radial lines.
Larger costellae obscure. Brachial valve gently concave.

Measurements in mm.—1176090, length 8.9, brachial length 7.6, midwidth
I1.1+, hinge width 11.3+, thickness 1.4, surface length 10.5, trail length 3.5.

Figured specimen.—117609.

Horizon and locality.—Sevier formation in Tennessee: + mile northeast of
Miser, Louisville (T.V.A. 138-SE) Quadrangle.

Discussion.—This species is suggestive of D. concentrica and is marked some-
what like it, but the brachial valve is more deeply concave and the trail is longer.

DACTYLOGONIA sp. 5
Plate 217, I, figures 23-26

This is an unusually well preserved specimen, but its form and lack of conspicu-
ous geniculation suggest that it is the young of a larger species not yet known.
The specimen is wider than long, with a gently convex pedicle valve and a moder-
ately concave brachial valve. The ornamentation consists of fairly regular distant

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 839

larger costellae numbering 11 or 12 with short intercalations of large costellae
at the front. These are separated from each other by 8 or possibly more fine
costellae. Concentric elements are not conspicuous. The foramen is large. The
brachial umbo is narrowly swollen and smooth, matching a smooth area in the
vicinity of the pedicle foramen.

Measurements in mm.—117610, length 8.1, brachial length 7.6, midwidth 10.9,
hinge width 11.9, thickness 1.7, surface length 9.0, height 1.9.

Figured specimen.—117610.

Horizon and locality —Effna formation in Virginia: At Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

DACTYLOGONIA sp. 6
Plate 218, FE, figures 15, 16

Shell large for the genus, wider than long, with the hinge forming the widest
part. Pedicle valve gently convex in lateral profile, mostly so in the anterior
quarter which forms an inconspicuous trail. Umbonal and median region some-
what narrowly swollen to form a low but inconspicuous fold on the posterior
three-quarters ; sides with short and steep slopes. Brachial valve concave, with
the maximum concavity located just anterior to the middle; visceral region gently
concave ; trail moderately long.

Measurements in mm.—

Brachial Hinge Thick- Surface Trail
Length length Midwidth width ness length length
Pedicle valve (117611a)... 12.5 ? 17.9 21.6 ? 14.0 2.0 ?

Brachial valve (117611d).. ? 14.3 24.6? 203 ? 16.0 6.0

Figured specimen.—117611a; measured specimen: 117611d.

Horizon and locality—Probably Benbolt formation (30 feet above the 225-foot
marble) in Tennessee: At Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle.

Discussion.—This species is a flatly convex one, not like any of those de-
scribed. Its ornamentation is suggestive of D. alternata, but it is not so strongly
geniculated.

DACTYLOGONIA sp. 7
Plate 217, G, figures 16-19

Shell of about medium size for the genus, wider than long, transversely sub-
rectangular. Surface marked by fine radial lines crossed by fine concentric
lines. Visceral region of pedicle valve nearly flat in lateral profile, slightly con-
vex in anterior profile. Place of geniculation about 8 mm. anterior to the beak;
angle of geniculation about 115°. Trail short. Foramen large. Visceral region of
brachial valve gently concave; umbo and median region of visceral area sulcate.

Measurements in mm.—117612a, length 11.6, brachial length 10.2, midwidth
17.2, hinge width ?, thickness 2.2, surface length 13.5, trail length 5.0.

Figured specimens.—117612a,b.

Horizon and locality—Whistle Creek formation in Virginia: Foot of Brushy

840 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Hills road to Lexington, 14 miles northwest of Lexington, Lexington (15)
Quadrangle.

Discussion——This species suggests D. geniculata, but the brachial valves are
more concave, the geniculation is less sharp, and the trail shorter.

DACTYLOGONIA sp. 8
Plate 216, A, figures 1-4

Shell small for the genus, wider than long; visceral region of both valves
marked by more or less obscure concentric wrinkles. Visceral region of pedicle
valve flat in lateral profile ; point of geniculation about 6 mm. anterior to the beak;
angle of geniculation about 95° ; trail moderately long, convex in profile. Place of
geniculation marked by a slight rim. Brachial valve with visceral part nearly
flat. Umbo and median part gently sulcate ; trail narrowly and sharply deflected.

Measurements in mm.—117613a, length 7.9, brachial length 7.0, midwidth
10.9, hinge width 12.0, thickness 2.3, surface length 10.5, trail length 5.0.

Figured specimen.—117613a.

Horizon and locality—FPoteet formation (Yellow Branch member) in Vir-
ginia: Along the Yellow Branch road, 5 miles southeast of Rose Hill (T.V.A.
161-NE) Quadrangle.

Discussion—The size and visceral region of this species suggest D. palustris,
but geniculation is too sharp and the trail too long.

CYPHOMENA Cooper, new genus

(Greek kyphos, bent; mene, crescent)

Shell generally transversely subrectangular in outline, concavo-convex in pro-
file; valves strongly geniculated toward the brachial valve. Surface marked by
fine subequal radial costellae crossed by fine concentric lines. Costellae not
grouped into zones of different sizes as in Dactylogonia. Pseudopunctate.

Pedicle valve with small but stout teeth; thick plates extend as a rim nearly
completely around the suboval muscle field. Diductor scars subcrescentic, elon-
gate, located on each side of a short, low median ridge which divides the muscle
field but is extended anteriorly for a short distance only. Incipient vascula media
extend directly anteriorly from the anterior ends of the diductors. Foramen and
pseudodeltidium leptaenoid.

Brachial interior with broad, shallow sockets, the inner wall of which is formed
by the outer face of a broad, flat brachiophore ; notothyrial cavity filled by a thick
platform which supports the cardinal process and nearly buries the brachiophore
with lateral extensions. Median ridge short, extending from notothyrial plat-
form and dividing the posterior adductors. Cardinal process formed of 2 nar-
row, short-shafted pieces with flat myophores. Chilidium strongly convex and
covering part of the myophore surfaces. Adductor field narrowly triangular or
arrow shaped in outline with the apex directed anteriorly; posterior adductors
the larger, located outside the anterior pair and apparently divided into pairs

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 841

by a more or less thick oblique ridge. Anterior pair elongate and separated by
a short, low median ridge.

Genotype.—Leptaena homostriata Butts, Virginia Geol. Surv. Bull. 52, p. 110,
pl. 95, figs. 24, 25, 1942.

Discussion—Cyphomena is essentially a side line of Leptaena which never
developed the concentric wrinkling of the visceral region and which, as far as
now known, was short lived. Besides the lack of wrinkling, Cyphomena differs
from Leptaena in lacking the standardized and abrupt geniculation of both valves.
The brachial valve is more suggestive of Leptaena in its geniculation because it
has a raised rim on the inside and a precipitous face to the trail. This is not so
of the pedicle valve, however.

Inside the brachial valve the musculature is like that of Leptaena including
the presence of the small longitudinal ridge. The brachial valve shows the
brachiophores more clearly than most specimens of Leptaena, in which these
structures are lost or covered. Although the muscle area of the brachial valve
of the two genera is similar, that of Cyphomena is generally somewhat elevated
or marked by a thickened rim, emphasizing its arrow-shaped form.

At the present time Cyphomena is certainly known only from Edinburg and
Oranda formations in Virginia, Maryland, and southern Pennsylvania. The
faunas of these two formations are closely related. From the material studied no
significant evolutional changes were detected during this short interval. A doubt-
ful species is known from the Chaumont near Montreal, Quebec, Canada.

CYPHOMENA ANGULATA Cooper, new species
Plate 224, A, figures 1-8; plate 224, C, figures 21, 22; plate 228, A, figures 1-7

Shells thick, wider than long and with the hinge forming the widest part;
cardinal extremities alate; sides gently oblique, anterolateral extremities nar-
rowly rounded; anterior margin gently convex to gently emarginate. Costellae
numbering about 4 to the millimeter at the front margin of an adult.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity near the middle; anterior profile broadly and moderately convex. Umbo
narrowly convex, the convexity continued anteriorly as a low fold to about the
place of geniculation 4 or 5 mm. anterior to the beak. Geniculated area broadly
rounded ; trail moderately long and gently convex ; median region of trail marked
by a more or less prominent sulcus. Muscle area deeply impressed.

Brachial valve moderately concave with the most concave part just posterior
to the place of geniculation. Visceral region gently concave; umbo slightly sul-
cate; geniculation moderate. Muscle area moderately thickened.

Measurements in mm.—

Brachial fst Hinge Thick- Surface Trail
Length length Midwidth width ness length length

Folotyper ssh dele. os 10.3 0.2 14.1 15.3 3.0 15.5 9.0
Paratype (117617a)... 9.7 8.7 12.8 14.8 Z2iG4> LeT3IOL? .. 61078

Types.—Holotype: 117619a; figured paratypes: 117614a, 117616a, 117617a,
117618, 117619b; unfigured paratypes: 117614b,c, 117616b,c, 117617b.

842 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality.—Edinburg formation (Cyrtonotella zone) in Virginia:
In the ravine at the switch 4 mile east of Strasburg Junction, Strasburg (15’)
Quadrangle.

Edinburg formation (Nidulites zone) in Virginia: Beside the road along
Tumbling Run, 14 miles southwest of Strasburg; on U. S. Highway If, at
Hupp Hill, 1 mile north of Strasburg, Strasburg (15’) Quadrangle.

Edinburg formation (Liberty Hall facies) in Virginia: 14 miles south of
Wadesville, Winchester (15’) Quadrangle.

Shippensburg formation (nodular shaly zone below Nidulites) in Pennsyl-
vania ; 13 miles west of Kauffman, Chambersburg (15’) Quadrangle; in the rail-
road cut 24 miles southwest of Marion, Chambersburg (15’) Quadrangle.

Shippensburg formation (Nidulites zone) in Maryland: In a cut on the west
bank of Conococheague Creek on U. S. Highway 40, 7 miles west of Hagers-
town, Williamsport (15') Quadrangle.

Discussion.—This is a rare species, and good specimens are very difficult to
obtain. In size it is intermediate between C. homostriata and C. grandis, being
generally larger than the first. Its sides are usually more oblique and the cardi-
nal extremities more alate than in C. homostriata. Cyphomena homostriata is
somewhat more finely costellate than the lower Edinburg species and has a flat-
tened umbo, whereas C. angulata has the umbo narrowly swollen to form a
short, low fold.

CYPHOMENA GRANDIS Cooper, new species
Plate 224, D, figures 23-36

Shell large for the genus, transversely subrectangular, the hinge forming the
widest part; sides gently oblique; anterolateral extremities moderately rounded ;
anterior margin indented; surface marked by 3 to 4 costellae in I mm. at the
front margin.

Pedicle valve with lateral profile strongly convex and with the greatest con-
vexity located anterior to the middle; visceral region convex in lateral profile.
Anterior convex, strongly domed and with steep sides. Visceral region mod-
erately convex ; umbo gently convex ; geniculated region narrowly convex; trail
long, gently convex in lateral profile. Median area of trail occupied by a broad
and shallow sulcus. Interareas subequal. Muscle area small, subcircular.

Brachial valve concave, the most concave part located just posterior to the
place of geniculation. Visceral region nearly flat; umbo nearly flat.

Measurements in mm.—

Brachial Hinge Thick- Surface Trail

Length length Midwidth width ness length length
TLOLOY POY Persist News. oaversto Te 10.5 18.6 ? 4.3 19.0 II.0
Paratype (11762Ib)... 13.9 ? 20.0 ? i 22.5 12.0
af (117620)... to 10.0 L743 ro 4.4 16.5 7.0

Types.—Holotype: 117621a; figured paratypes: 117620, 117621b; unfigured
paratype: 11762Ic. .
Horizon and locality—Martinsburg formation (part with Brongniartella=

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 843

Salona) in Virginia: On County Highway 617=910, 0.15 miles north of Green
Mount Church, Broadway (15’) Quadrangle.

Discussion—This is the largest known species of the genus and in its adult
form is thus readily distinguished from the other two known species. It is pro-
portionately wider than the other two and is somewhat more strongly costellate.

CYPHOMENA HOMOSTRIATA (Butts)
Plate 223, D, figure 7; plate 224, B, figures 9-20
Leptaena homosiriata Butts, Virginia Geol. Surv. Bull. 52, p. 110, pl. 95, figs. 24, 25, 1942.

Small, subrectangular in outline and with the hinge forming the widest part;
sides gently oblique; anterolateral extremities narrowly rounded; anterior mar-
gin gently convex to truncated. Surface finely costellate, 4 to 6 costellae in a
millimeter at the front margin of an adult.

Pedicle valve strongly convex in lateral profile, the greatest convexity located
at about the middle; anterior profile domed and with steep sides but the median
part depressed by a sulcus. Visceral region nearly flat in profile; geniculated
part narrowly rounded; trail gently convex in lateral profile. Visceral region
gently convex; trail moderately long and marked by a prominent sulcus. Flanks
of trail bounding sulcus rounded and somewhat swollen.

Brachial valve gently concave, the deepest part located near the place of genicu-
lation. Visceral region gently concave. Trail short, marked medianly by a low
and inconspicuous fold. Muscle area narrowly arrow shaped, moderately
thickened.

Measurements in mm.—

Brachial Hinge Thick- Surface Trail

Length length Midwidth width ness length length
ELGOLY HE coca cet ets 8.1 7.4 10.4 Ties 3.2 13.5 6.0
Paratype (117622).... 7.7 6.6 10.3 ? 3.0 II.5 6.0

§ (117623a)... 8.2 7.4 11.7 rise PY | 11.5 6.0

Types—Holotypes: 97545, figured hypotypes: 117615, 117622, 117623,
117624.

Horizon and locality—Oranda formation in Virginia: Along the railroad
4 mile west of Strasburg, Strasburg (15’) Quadrangle; on the Shenandoah
River, 14 miles N. 61° E. of Edinburg, Edinburg (15’) Quadrangle; Bowman
Farm, 0.3 mile east of U. S. Highway 11, on the south edge of Woodstock,
Edinburg (15’) Quadrangle ; just west of the junction of Virginia County High-
ways 617=910, and 777, about 4 mile north of Green Mount Church, Broadway
(15’) Quadrangle.

Oranda formation in Pennsylvania: 13 miles west of Kauffman, 4 mile north
of Greencastle, Chambersburg (15’) Quadrangle.

Discussion.—This species is the smallest of the three known species and is
generally somewhat squarer than the other two in outline. It is also somewhat
more finely costellated and has a somewhat flattened umbonal region. It is usu-
ally not so alate as C. angulata.

844 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

CYPHOMENA ? RADIALIS (Okulitch)
Plate 223, G, figure 18
Leptaena radialis OkuLItcH, Canadian Field-Nat., vol. 49, No. 6, p. 99, pl. 1, fig. 9, 1935.

The outline, profile and ornamentation suggest affiliation with Cyphomena.

Type.—Holotype: McGill Univ. (no number).

Horizon and locality—Lower Leray formation (=Chaumont) in Quebec,
Canada: At St. Vincent de Paul.

MURINELLA Cooper, new genus

(Latin murus, wall)

Generally large and thick shells, semielliptical to subquadrate in outline; gen-
erally biconvex or planoconvex to rarely concavo-convex; pedicle valve gen-
erally strongly convex; costellate, the costellae of two sizes, the stronger ones
standing out in a mat of finer ones and dividing the finer ones into groups. Fine
costellae may or may not be cancellated by fine concentric threads. Pseudo-
punctate.

Pedicle valve with large, wide, strongly convex pseudodeltidium ; pedicle fora-
men moderately large, leptaenoid in character. Teeth wide, small; dental plates
short, flaring, separated from shell wall by small and narrow umbonal chambers ;
muscle area large and subcircular; diductor-adductor scars flabellate ; adductor
scars long and slender, separated by a low ridge that is continued anterior to the
anterior ends of the muscles for a considerable distance ; margin usually some-
what thickened.

Brachial interior with an obscure, thin and flat-bladed brachiophore supported
by lateral swellings on each side of the cardinal process ; sockets deep and wide;
cardinal process consisting of 2 short-shafted processes located on a more or less
thickened notothyrial platform ; myophore surfaces tear shaped, concave; median
ridge extending anterior to the cardinal process short, low, obscure and not
extending anterior to the posterior adductors. Adductor field large, posterior
adductors 4 in number, the outer 2 larger than the inner 2; inner and other
scars often separated by low, oblique ridges; anterior pair small; 2 vascula
media extending directly anterior to the anterior adductor pair and extending
anteriorly nearly to the flange; marginal area marked by a more or less strongly
elevated peripheral band or flange.

Genotype.—Murinella partita Cooper, new species.

Discussion.—Leptaenoid characters of this genus are: The fairly large apical
foramen; the large and swollen pseudodeltidium, the subcircular muscle field
of the pedicle valve ; the short-shafted, bilobed cardinal process ; and the arrange-
ment of the adductor scars. This genus differs from most other leptaenoids in
having planoconvex to biconvex valves. One or two species have concave brachial
valves, but even these species have the younger stages characterized by both
valves being more or less strongly convex.

Murinella is ornamented like Dactylogonia but is not strongly geniculated like
it and the brachial interiors are quite unlike. Although Murinella often has

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 845

ridges dividing parts of the adductor field these do not take the form of the
blades so characteristic of Dactylogonia. The shape and ornamentation serve to
distinguish Leptaena, Cyphomena, and Bellimurina from Murinella. The inner
flange just inside the anterior margin of the brachial valve is a character dis-
tinguishing this genus from all other known leptaenoids.

Although Murinella is a distinctive and fairly widely distributed genus both
stratigraphically and geographically, the known specimens are not many. The
genus seems to be quite rare except in a few places.

MURINELLA BICONVEXA Cooper, new species
Plate 227, C, figures 8-16

Shell of about medium size for the genus, subequally biconvex ; greatest width
at about middle; hinge width less than greatest width; anterior commissure rec-
timarginate; sides somewhat narrowly rounded; anterior margin broadly
rounded. Cardinal extremities obtuse. Surface marked by costellae of unequal
size, I to 3 of the smaller kind separated by larger ones. Strong, elevated con-
centric lines cancellate the costellae.

Pedicle valve moderately and unequally convex in lateral profile with the great-
est convexity located in the posterior half; anterior half somewhat flattened.
Median region slightly swollen with gentle slopes to the anterior and anterolateral
margins but somewhat steeper slopes to the cardinal extremities.

Brachial valve with concave umbo; profile unequally convex with the greatest
convexity located at about the middle; anterior profile broadly convex ; median
region swollen but with gentle slopes in all directions.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype? 08 22S. ets 11.2 10.6 15.6 12.0 4.6
Paratype (117620b)ibe.c ds 1p) 11.0 15.4 12.1 4.6
ee GG A0¢ 0) Ne ene eee 10.5 9.8 14.4 ? 3.0

Types.—Holotype: 117629a; figured paratypes: 117629b, 117630.

Horizon and locality —Lincolnshire formation (Hogskin member) in Ten-
nessee: $ mile southwest of Washburn, Dutch Valley (T.V.A. 154-SE) Quad-
rangle; 3 mile southwest of Mount Eager Church, Powder Springs (T.V.A.
154-SW) Quadrangle.

Discussion—This species is characterized by its small size and fairly strongly
convex valves. It differs from the only two other species like it in the uniformity
of the convexity of the valves. Murinella plana is a small species nearly of the
same size as M. biconvexa, but its brachial valve is nearly flat and the orna-
mentation is stronger and not so beautifully cancellated. Murinella speciosa is
somewhat larger than M. biconvexa, but its pedicle valve is convex in the pos-
terior part, becoming concave anteriorly. Its ornamentation is also somewhat
stronger than that of M. biconve.xra.

846 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

MURINELLA CANCELLATA Cooper, new species
Plate 217, H, figures 20-22

Shell large, with the widest part just anterior to the hinge, cardinal extremi-
ties rounded, obtuse; lateral margins gently rounded, sloping to the middle;
anterior margin broadly rounded. Surface marked by costellae of unequal size,
separating areas of fine costellae; 3 or 4 of the larger costellae occupy a space
of 5 mm. at the front and as many as Io of the finer costellae may occupy the
spaces between the larger ones; all costellae are crossed by fine elevated lines,
about 5 to a millimeter near the middle, which produce a cancellated effect.

Pedicle valve fairly strongly convex, with the greatest curvature anterior to
the middle; umbonal region convex and area anterior to umbo somewhat swol-
len ; lateral and anterior slopes moderately steep ; valve not markedly geniculated
but surface is bent toward the brachial valve about 13 mm. anterior to the beak.
Palintrope short for such a large shell; interarea flat, approximately orthocline.
Foramen small.

Brachial valve with visceral area slightly convex for 10 mm. anterior to the
beak where the valve is bent at an obtuse angle toward the brachial valve. Genicu-
lated rim about 6 mm. long. Chilidium short, cardinal process large.

Measurements in mm.—Holotype, length 18.8, brachial length 16.4, midwidth
23.4, hinge width 22.6, thickness 5.4.

Type.—Holotype: 117631.

Horizon and locahity.—Benbolt formation in Virginia: West of Rye Cove,
Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—This is a large species characterized by a fairly deeply concave
brachial valve and beautifully cancellated shells. It is much larger than
M. speciosa and differently ornamented. It is very suggestive of M. semureducta,
but that species has a less deeply concave brachial valve and is proportionately a
much wider species. This species differs from M. muralis and M. partita in the
strongly concave brachial valve.

MURINELLA MURALIS Cooper, new species
Plate 226, D, figures 10-28

Shell large, planoconvex in profile, semielliptical in outline; anterior com-
missure rectimarginate ; lateral margins gently rounded ; widest part of shell just
anterior to hinge; anterior margin broadly rounded. Surface marked by costellae
of unequal size, 4 or 5 smaller costellae between the larger ones and all crossed
by strong concentric lines.

Pedicle valve strongly convex in lateral profile, with greatest convexity near the
middle. Median region swollen and with moderately steep slopes to the anterior
and lateral margins. Teeth moderately large with sockets parallel to the hinge;
dental plates short and flaring, with small umbonal cavities separating them from
the inner side of the valve. Muscle area i impressed, transversely elliptical
to subcircular in outline.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 847

Brachial valve nearly flat in lateral profile, interior with bilobed, cardinal
process, 4 adductor septa and a thickened inner rim.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (pedicle valve)........... 14+ if 15.4+ 14.8 4.6
Paratype (pedicle valve 117636b).. 19.3 ? 22.4 20.0 5.4
“ (brachial valve 117637a).. ? 12.3 17.0 15.5 1.5
4 G..e5 Ge 2 nr703z6e it StF 18.5 25.7 21.5 2.0

Types——Holotype: 117636a; figured paratypes: 117632a, 117633, 117635¢,
117636b-f, 117637a,b; unfigured paratypes: 117632b,c, 117635a,b, 117636g,h,
117637¢,d.

Horizon and locality—Wardell formation in Tennessee: In Raccoon Valley,
3 mile northeast of Fleanor Mill, Powell Station (T.V.A. 137-SE) Quadrangle.

Dryden formation (and Wardell part) in Tennessee: Along the road to
Tazewell 14 miles northeast of Lone Mountain, Tazewell (T.V.A. 154-NE)
Quadrangle.

Poteet formation (Yellow Branch member) in Virginia: Along the road beside
Yellow Branch, 5 miles southeast of Rose Hill, Rose Hill (T.V.A. 161-NE)
Quadrangle.

Discussion.—This species is characterized by its large size and generally plano-
convex profile. It is most like M. partita from the Bromide formation of Okla-
homa but differs in being less convex and in having a more extravagant de-
velopment of the median ridge inside the brachial valve. The septa associated
with the adductor scars in M. muralis are more prominently developed than they
are in M. partita. Inside the pedicle valve of M. muralis the dental plates are
somewhat more fully developed. The greatest width of M. muralis is nearer the
hinge whereas in M. partita it is nearer the middle.

MURINELLA PARTITA Cooper, new species
Plate 223, F, figures 11-17; plate 227, D, figures 17-25

Shell large, variable, wider than long; planoconvex to biconvex, the pedicle
valve being the deeper; greatest width at or near the middle; sides gently
rounded; anterior margin broadly rounded; surface marked by costellae of un-
equal size, the larger ones separated by 2 to 4 of the finer ones.

Pedicle valve moderately convex in lateral profile and with the maximum
convexity at about the middle; anterior profile moderately domed in the median
region and with long, moderately steep lateral slopes; umbonal region swollen ;
median region swollen; anterior and lateral slopes subequal, moderately steep.
Interior with subcircular muscle field confined to the posterior third; diductor
scars somewhat elongated anteriorly ; median ridge long and slender.

Brachial valve varying from gently convex to nearly flat in lateral profile;
umbo concave, the concavity continued anteriorly at least to the middle as a
shallow sulcus; flanks flat or gently convex ; Interior with stout cardinal process ;

848 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

adductor field moderately large; adductor processes moderately developed. Four
parallel pallial trunks extend anteriorly from the adductor field.

Measurements in mm.—Holotype, length 18.2, brachial length 16.2, midwidth
23.7, hinge width 20.0 ?, thickness 6.6.

Types.—Holotype: 117639; figured paratypes: 117638, 117640.

Horizon and locality.—Bromide formation (Mountain Lake member) in Okla-
homa: In the road cut on Oklahoma Highway 18, 1.8 miles south of Sulphur,
Murray County ; along the creek on the Fitz place, SE} sec. 27, T.2S., R.3 E,,
14 miles west and # mile south of Nebo, Murray County ; in the Sowerbyites bed;
150 feet below the top of the Bromide 0.1 mile down the hill from the Observa-
tion Point on the Scenic Drive, 1 mile east of U. S. Highway 77, in the center
NW4ANW43 sec. 29, T. 1 S., R. 2 E., Murray County.

Discussion.—This species is a ieee one having a strong superficial resemblance
to M. muralis. The chief differences are in the location of the greatest width of
M. partita at or near the middle instead of near the hinge as in the Appa-
lachian species. Differences appear in the interior also. The dental plates of
M. muralis are the better and more fully developed, and the subperipheral rim
of M. muralis is much more extravagantly developed than in the Oklahoma
species. The latter also differs in the arrangement of the pallial trunks in the
brachial valve, there being 4 in M. partita but only 2 in the other species.

It is interesting to note that 7. partita was found in the reefy limestones south
of Sulphur where it occurs with Sowerbyites.

MURINELLA PARVA Cooper, new species
Plate 217, B, figures 2, 3

Shell small for the genus, wider than long and with the greatest width at
about the middle; sides gently rounded; anterior margin broadly rounded; sur-
face marked by alternating strong and fine costellae, about 3 or 4 to the milli-
meter at the front margin and the stronger costellae separated by 2 to 4 costellae ;
entire surface covered by strong concentric, elevated lines.

Pedicle valve gently convex in lateral profile, broadly and moderately convex
in anterior profile; umbonal and median regions swollen; anterior slope long
and gentle ; lateral slopes moderately long and moderately steep. Interarea mod-
erately long; pseudodeltidium large and strongly convex.

Pedicle valve perceptibly concave in lateral profile ; broadly concave in anterior
profile ; umbo concave.

Measurements in mm.—Holotype, length 9.2, brachial length 8.3, midwidth
11.4, hinge width 11.0, thickness 2.3.

Type.—Holotype: 117643.

Horizon and locality—Whistle Creek formation, in Lexington (15’) Quad-
rangle, Virginia: On U. S. Highway 60, 100 yards southeast of Whistle Creek,
2 miles northeast of Lexington; 14 miles northwest of Lexington.

Discussion.—This is a small species of about the same size as M. plana. It
differs from that species, however, in having a moderately concave brachial valve
and finely cancellated ornamentation. |

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 849

MURINELLA PLANA Cooper, new species
Plate 227, B, figures 6, 7

Small, wider than long and with the widest part at about the middle; sides and
anterior margin rounded; surface marked by fairly strong costellae with finer
ones intercalated between the stronger ones in several generations; 2 of the
stronger costellae in 1 mm. at the front margin.

Pedicle valve moderately convex and with the greatest depth at the middle;
anterior profile broadly domed, rounded in the middle with moderately long and
moderately steep lateral slopes. Umbonal and median regions swollen. Anterior
slope short, gentle.

Brachial valve nearly flat to slightly convex in lateral profile; anterior profile
gently convex. Umbo gently concave.

Measurements in mm.—Holotype, length 9.6, brachial length 8.5, midwidth
11.5, hinge width 9.6, thickness 3.7.

Types.—Holotype: 117644a; unfigured paratype: 117644b.

Horizon and locality—tLincolnshire formation (Hogskin member) in Ten-
nessee: Evans Ferry about 1 mile north of Indian Creek on U. S. Highway 25F,
Howard Quarter (T.V.A. 162-NE) Quadrangle.

Discussion.—This species is characterized by a flat brachial valve, strong cos-
tellae, and small size. It differs from M. parva which has a concave pedicle valve
and from M. speciosa in which the brachial valve is convex in the posterior half
but is concave in the anterior half.

MURINELLA SEMIREDUCTA Cooper, new species
Plate 227, A, figures I-5

This is a large species having a transversely semielliptical outline and with the
maximum width at about the middle. Pedicle valve not preserved except for the
posterior, probably moderately to strongly convex. Brachial valve with concave
umbo. Region surrounding umbo for about half the valve length nearly flat;
area surrounding flattened part gently concave and with the margins deflected
moderately toward the brachial valve. Pedicle interior with fairly large muscle
field, subcircular in outline; dental plates strong, moderately divergent, and with
fairly large and deep umbonal cavities.

Brachial interior with broad notothyrial platform, small cardinal process, and
low adductor ridges. Ornamentation like that of M. cancellata with strong
costellae separated by groups of finer ones, all cancellated by concentric costellae.
Submarginal rim long and almost reaching margin.

Measurements in mm.—Holotype, length 15.8, brachial length 14.7, midwidth
26.0, hinge width 22.4, thickness ?.

Type.—Holotype: 117645.

Horizon and locality.—Lincolnshire formation (Hogskin member) in Ten-
nessee: On the Sally Cleveland Farm, 3 mile southwest of Washburn, Dutch
Valley (T.V.A. 154-SE) Quadrangle.

Discussion.—This species is characterized by its large size, transversely semi-

850 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

elliptical outline, and the flattened posterior half of the brachial valve. It is most
like M. cancellata in general proportions and ornamentation but differs in having
its greatest width nearer the middle, in being less concave anteriorly and in a
generally flatter brachial valve.

MURINELLA SPECIOSA Cooper, new species
Plate 228, D, figures 20-26

Shell large, transversely semielliptical ; widest part at about the middle; sides
rounded; anterior margin broadly rounded; surface marked by fairly strong
alternating costellae, the larger ones separated by 1 to 3 finer ones.

Pedicle valve moderately convex in lateral profile and with the maximum con-
vexity near the middle; anterior profile broadly and moderately convex; um-
bonal region gently convex; median region moderately swollen ; anterior slopes
shorter and steeper than the lateral ones; interarea moderately long; pseudo-
deltidium somewhat narrow, convex.

Brachial valve unevenly convex in lateral profile, the posterior half moder-
ately convex but the anterior half moderately concave; umbo gently concave ;
region immediately anterior to the umbo moderately swollen to about the middle
of the valve; around the swollen area the valve is moderately concave but the
marginal region is turned back toward the brachial valve.

Measurements in mm.—Holotype, length 14.0, brachial length 12.5, midwidth
18.0, hinge width 13.7, thickness 5.2.

Type.—Holotype: 117646.

Horizon and locality—Lincolnshire formation (Hogskin member—Oligo-
rhynchia zone) in Tennessee: 0.4 mile east-northeast of Red Hill, 4 miles west-
southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle.

Discussion.—This species is suggestive of Murinella cancellata, but it is much
smaller and the posterior half of the brachial valve is much more convex. Muri-
nella biconvexa is similar in size but has a brachial valve of almost the same
convexity as that of the pedicle valve.

MURINELLA sp. 1
Plate 226, B, figures 3, 4

Species represented by a single impression of the interior showing the muscle
field to perfection. The scars of the diductors are subflabellate; the small tear-
shaped adjustor scars appear outside the diductors. The adductor scars are small
and located on the sides of the narrow median ridge. The posterior ends of the
vascula media, parallel and separated only by a thin ridge, appear at the anterior
ends of the diductors.

Figured specimen.—117647.

Horizon and locality.—Murfreesboro formation in Tennessee: On the east
edge of Murfreesboro, Murfreesboro (15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 851

MURINELLA sp. 2
Plate 217, A, figure 1

Large, transversely semielliptical in outline, with the hinge equal to or slightly
less than the greatest shell width ; sides rounded, slightly oblique. Anterior mar-
gin broadly rounded; surface marked by alternating strong and fine costellae.

Pedicle valve unevenly convex in lateral profile, the most convex part being
the middle ; anterior profile broadly domed. Posterior half or more gently convex
to nearly flat ; anterior half somewhat abruptly bent toward the brachial valve to
form a long trail which is gently convex in lateral profile. Muscle area small,
subcircular. Brachial valve nearly flat.

Figured specimen.—117648a.

Horizon and locality —Tulip Creek formation in Oklahoma: On west branch
of Sycamore Creek, sec. 27, T. 3 S., R. 4 E., Johnston County.

MURINELLA sp. 3
Plate 226, A, figures I, 2

A single brachial valve is nearly flat in lateral and anterior profile and is
marked by distant, strong costellae separated by numerous (as many as IT)
fine costellae all cancellated by fine concentric lines. The interior is distinctly
leptaenoid with a broad notothyrial platform surmounted by a small, delicate
leptaenoid cardinal process. The muscle area is indistinct and a double sub-
peripheral rim suggests the type of structure in the brachial valve of Murinella.

Figured specimen.—117649.

Horizon and locality—Little Oak formation (top third) in Alabama: 1 mile
north of Pelham, Bessemer Iron District (15’) Quadrangle.

LIMBIMURINA Cooper, new genus

(Latin limbus, border; murus, wall)

Shell attaining a length and width of about 1 inch; subrectangular to semi-
elliptical in outline; compressed biconvex in profile; anterior and sides marked
by an elaborate frill geniculated toward the pedicle valve. Visceral region marked
by irregular wrinkles; entire surface marked by fine costellae and concentric
lines of growth.

Pedicle valve with small foramen, strong divergent dental plates, a moderately
large, subcircular muscle area surrounded by elevated ridges extending from the
dental plates and a short low, median ridge dividing the muscle field and extended
some distance anterior to it.

Brachial interior with thin, bladelike brachiophores, wide sockets, moderately
thick notothyrial platform bearing a cardinal process consisting of 2 short
shafted prongs with concave myophores. Adductor field with prominent oblique
ridges.

Genotype.—Limbimurina insueta Cooper, new species.

Discussion.—The distinctive feature of this genus is the elaborate frill which

852 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

surrounds the visceral region, and which probably served as a sort of anchoring
device. The visceral part of the shell is usually small and is separated from
the frill by a deep and prominent groove. The posterior side of the frill is a
steep wall extending in the direction of the pedicle valve and ending in a narrow
ridge. The main part of the frill in the pedicle valve extends from this ridge.

The visceral area of the brachial valve is surrounded by a sharp and narrow
_ ridge which is elevated more or less strongly above the visceral region. The
anterior slope of this ridge is steep and long and ends in a narrow groove. At
the anterior end or bottom of this slope the main part of the frill extends forward
and laterally.

The interior details of this genus are not easily discerned from the material
available. Each of the features recorded has been gleaned from study of many
specimens. To date no good interiors have been found. The information on the
cardinalia were derived from 2 fragments dissolved out of Lower Edinburg lime-
stone. In spite of these difficulties most of the details have been learned.

The interior of this genus is most like that of Murinella and shares with it the
prominent dental plates and the more or less strong adductor ridges. The interior
of the pedicle valve of Murinella is not provided with the prominent, elevated
ridge around the visceral area seen in Limbimurina, but that is a deviation
brought about by the elaborate frill.

Limbimurina is not rare in parts of the Rodman formation in central Pennsyl-
vania but is a rare shell in the lower part of the Edinburg formation. The occur-
rence of this bizarre form in the Lower Edinburg and the high Chambersburg
and Salona emphasizes again the continuity of these two faunas. In the Rodman
of central Pennsylvania Limbimurina is most often found in coarse calcarenites.
It is not possible to be sure if this was the actual environment of this peculiar
brachiopod or if the shells only represent debris washed into a sand bank. The
shells in the calcarenite are usually single valves only and thus may have been
banked up with the lime sand and broken bryozoans as a part of the bottom
debris.

The occurrence of Limbimurina shells in the Edinburg formation is not unlike
that in the Rodman formation. Here, too, the lithology is either calcarenite or
shell breccia, and most of the specimens are taken as single valves. The environ-
ment is one of agitated water and if it was the locale for these shells, the ex-
panded frills would have been of advantage in keeping the shells from being
tipped over, particularly if steadied by a pedicle.

LIMBIMURINA BREVILIMBATA Cooper, new species
Plate 173, G, figures 32-34; plate 222, E, figures 6-9; plate 223, B, figure 4

Shell large, attaining a width of 0.6 inch; transversely subrectangular in out-
line ; hinge forming widest part ; sides oblique ; anterior margin broadly rounded ;
surface marked by strong costellae separating groups of fine costellae beautifully
cancellated by concentric lines; as many as 6 fine costellae constituting a group.
Wrinkles irregular and variable but those along the posterior margin strong and
fairly regular.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 853

Pedicle valve gently convex in lateral profile; anterior profile gently convex
but with the median region narrowly and sharply pinched in the middle; umbo
and median region somewhat narrowly swollen to form an indistinct fold that dis-
appears at the place of geniculation. Visceral region 8 to 9 mm. long; posterior
slope of trail short; trail short, moderately steep.

Brachial valve fairly evenly and gently convex in anterior and lateral profiles ;
median region marked by an indistinct sulcus; flanks gently convex; trail short.

Measurements in mm.—

Length
Brachial Hinge Thick- aoc Trail
Length length Midwidth width ness region length
FiGlotype fd OS. 11.4 ? 16.4 18.0 1.5 9.0 2.0
Paratype (117661a).... 13.0 ? 16.8 20.5 215 8.5 5.0
ss (027662) / 3... 40? 8.3 10.8 11.6 1.4 8.3 ?
c (i17662e)))-2 .. ? 10.7 13.6 18.0 2 8.3 250°

Types.—Holotype: 117662a; figured paratypes: 117661a,b, 117662b-d; un-
figured paratypes: 117662e-i.

Horizon and locality.—Edinburg formation (Cyrtonotella zone) in Strasburg
(15’) Quadrangle, Virginia: On the railroad at the switch and in the ravine
about 4 mile east of Strasburg Junction; on the south side of the road 0.2 mile
east of Strasburg Junction.

Botetourt formation: Same as above.

Discussion.—This species is represented by about 25 specimens, but not one of
them is a complete valve except the holotype. Several of the specimens evidently
represent immature forms that have not yet developed the trail. One very poorly
preserved specimen from the ravine east of Strasburg Junction shows this species
to have been nearly as large and extravagantly developed as L. insueta from
the Rodman formation of Pennsylvania. The specimen referred to preserves
part of the trail which is 8 mm. long.

This species differs from L. imsueta in having stronger and more regular
wrinkles along the posterior margin and in having a shorter trail.

LIMBIMURINA INSUETA Cooper, new species
Plate 220, D, figures 18-23; plate 221, F, figures 37-42

Shell variable, attaining an inch in length and width; subquadrate to subrec-
tangular in outline; sides nearly straight; anterior margin broadly rounded ;
surface finely costellate ; visceral region marked by fine irregular wrinkles.

Visceral region of pedicle valve gently convex in both profiles ; umbo narrowly
swollen; median region gently swollen to form an indistinct fold; flanks flat-
tened. Place of geniculation about 9 mm. anterior to the beak. Posterior slope
of trail long and steep; trail variable, usually fairly long.

Brachial valve gently convex in lateral and anterior profile; visceral region
bounded anteriorly by a sharp rim; umbo sulcate; sulcus somewhat obscure an-
terior to the umbo; flanks gently convex; posterior of trail marked by a deep
trough peripheral to the visceral area; trail long.

854 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—
Visceral

Brachial Hinge disk Trail

Length length Midwidth width Height length length

elbty pe fiance cai 15.3 ig 15.4 15.0 3.1 8.5 7.0
Paratype (117660a)... 23.9 ? 30.4 26.2 3.0 9.5 15.0
i (117660b)... ? 16.8 20.0? 26.0 22° A 10.4

af (157658) 44 38 14.2 17.4 17.5 ? 9.2 5.3

B (117659b)... 14.6 ? 16.3 12.8 2.8 8.5 6.5

2 (G@aI7G50c)Aaea e 14.0 18.0 15.7 ? 8.5 5.5

Types.—Holotype : 1176592 ; figured paratypes : 117658, 117659b,c, 117660a,b ;
unfigured paratypes: 117659d-g.

Horizon and locality—Rodman member of Nealmont formation in Pennsyl-
vania: On the old road north of Roaring Spring, Hollidaysburg (15’) Quad-
rangle; 65 feet below top on the Pennsylvania RR. 4 mile north of Roaring
Spring, Hollidaysburg (15’) Quadrangle; 15 feet below the top in the west end
of the quarry at Salona, Lock Haven (15’) Quadrangle; 15 and 30 feet below
the top in the bluff south of Pennsylvania Highway 44, 150 yards east of the
road to Oriole, east of Antes Gap, Williamsport (15’) Quadrangle; 5 to 6 feet
and 50 to 60 feet below the top in the cut on Pennsylvania Highway 164, 100
yards east of Plum Creek at East Sharpsburg, Hollidaysburg (15’) Quadrangle.

Discussion.—The only species to which this one can be compared is L. brevi-
limbata from which it differs in having finer wrinkles on the visceral region and
a longer frill.

BELLIMURINA Cooper, new genus

(Latin bellus, pretty; murus, wall)

Shell of moderate size, biconvex in young stages but concavo-convex in the
adult. Hinge narrower or wider than the greatest shell width. Cardinal extremi-
ties alate to obtuse. Surface marked by costellae of unequal size, the stronger
ones separating groups of the smaller ones; in addition to costellae, visceral area
of shell marked by zigzag wrinkles. Valves strongly geniculated toward the
brachial valve just anterior to the biconvex visceral region. Pseudopunctate.

Pedicle valve with moderately long palintrope, covered delthyrium; pseudo-
deltidium large, convex; foramen small, apical. Teeth wide and large, dental
plates flaring with small umbonal chambers. Delthyrial chamber moderately
deep ; muscle field wide and short, with a low median adductor ridge.

Brachial valve shallow but with a high and narrow peripheral rim; chilidium
strongly convex, arching over a large cardinal process consisting of 2 parts, each
with short shaft and myophore showing attachment surfaces for a pair of muscles
located on the notothyrial platform. Brachial processes flat blades supported by
callus deposited at a low angle to the hinge line. Median ridge short, adductor
field small.

Genotype.—Leptaena charlottae Winchell and Schuchert, Amer. Geol., vol. 9,
p. 288, Apr. 1, 1892.

Discussion—The members of this genus are not easy to recognize and may be
confused with young of Limbimurina. The most significant feature of Bellimu-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 855

rina is the irregular wrinkling of the visceral region of both valves and the lack
of geniculation or the modest development of that feature. Bellimurina is quite
unlike Leptaena in both respects. In the latter genus wrinkling is usually quite
uniform, concentric, and strong. Geniculation in that genus, in contrast to this
feature of Bellimurina, is very strong and often at an angle of about 90°.

The interior of Bellimurina is most like that of Murinella but lacks the strong
subperipheral band in the brachial valve as in the latter genus. The median
ridge extending a short distance anterior to the notothyrial platform of Belli-
murina is somewhat stronger than that feature in Murinella.

Bellimurina is generally an uncommon genus and when found is usually identi-
fied as Leptaena charlottae. The wide identification of this species has misled
some authors to age assignments and correlations that are unwarranted. This
genus occurs in the Platteville limestone of the upper Mississippi Valley, but the
specimens in the National Collection are not suitable for description. In the
Southern Appalachians the genus is known from the Pratt Ferry limestone up.
Several species are here described on the basis of pedicle valves only because
of the fairly distinctive wrinkling of these individuals. The brachial valve is
usually not as important for description of species of this genus as the pedicle
valve.

A few specimens of Bellimurina are known that are as strongly geniculated
as most of the members of the genus Dactylogonia. These seem to be exceptions.
Bellimurina is readily distinguished from Dactylogonia by its lack of the strong,
bladelike adductor plates so characteristic of the latter.

BELLIMURINA CHARLOTTAE (Winchell and Schuchert), 1892
Plate 222, G, figures 11-14; plate 223, H, figures 19-24

Leptaena charlottae WINCHELL and ScHuUcHERT, Amer. Geol., vol. 9, p. 288, Apr. 1, 1892;
Geol. Minnesota, vol. 3, p. 410, pl. 32, figs. 1-5, 1895.—BAssLER, Cambrian and Ordovi-
cian: Maryland Geol. Surv., p. 257, pl. 41, figs. 11-13, 1910.

Strophomena halli, Sarveson, Minnesota Acad. Nat. Sci., Bull. 3, p. 334, pl. 4, figs. 36-38,
Apr. 9, 1802.

Types.—Figured hypotypes: Y.P.M. $3619, S3620a,b; U.S.N.M. 45358a.

Horizon and locality Decorah formation (Rhinidictya bed of the Guttenberg
member) in Minnesota: At West St. Paul and Minneapolis.

Discussion.—Some specimens of this species are suggestive of Dactylogonia
in the form of the pedicle valve and the degree of geniculation. These seem to
be exceptions, however, and the majority of specimens are not strongly
geniculated.

BELLIMURINA COMPRESSA Cooper, new species
Plate 221, D, figures 23-28
Shell small, biconvex but with brachial valve having the greater depth; wider
than long ; widest part at about the middle; sides and anterior margins rounded ;

surface of visceral region marked by oblique, concentric, irregular wrinkles.
Alternating costellae cover the entire surface.

856 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve gently convex in lateral profile but with the anterior third some-
what flattened; anterior profile gently convex; median region slightly swollen.
Interarea short, strongly apsacline; foramen large.

Brachial valve unevenly convex in lateral profile, the posterior half somewhat
flattened but the anterior half gently convex; median region marked by a shal-
low, irregular sulcus extending from the beak to the anterior margin; flanks
bounding sulcus swollen; lateral slopes short and moderately steep.

Measurements in mm.—Holotype, length 8.5, brachial length 8.4, midwidth
10.8, hinge width 9.0, thickness 2.8.

Type.—Holotype: 117653.

Horizon and locality.—Bromide formation (Mountain Lake member) in Okla-
homa: From the top of the green shale on the east side of the cut on Oklahoma
Highway 18, 1.8 miles south of Sulphur, Murray County.

Discussion—This species is characterized by its small size and the com-
pressed, biconvex form. It is suggestive of B. subquadrata but is a smaller and
differently shaped species. Furthermore, the wrinkling of the two species is
quite different. Bellimurina compressa is marked by finer wrinkles, particularly
in the marginal regions, than B. subquadrata.

BELLIMURINA CONCENTRICA Cooper, new species

Plate 222, A, figures 1, 2

Shell of about usual size for the genus, wider than long and with the hinge
forming the greatest width. Sides gently oblique; anterior margin rounded.
Pedicle valve gently convex in both profiles; umbo somewhat swollen; antero-
median region marked by a shallow depression. Umbonal and posterior region
marked by fine interrupted wrinkles; anterior and lateral areas marked by
strong, discontinuous wavy wrinkles. Brachial valve gently convex.

Measurements in mm.—Holotype, length 9.8, midwidth 14.4, hinge width 15.4,
thickness 1.9?.

Type.—Holotype: 117650.

Horizon and locality.—Pierce formation in Tennessee: At Pierce Mill, on
Stone River at crossing with Tennessee Highway 10 just south of Walterhill
about 74 miles north of Murfreesboro, Rutherford County.

Discussion.—This is a fairly large species definitely suggestive of Leptaena
but not strongly geniculated. The umbonal and median regions are marked by
the short, interrupted wrinkles characteristic of Bellimurina. The strength of
the wrinkles of this species suggest B. subquadrata, but concentric wrinkles of
the lateral and anterior region are much stronger and more regular. No other
described species is really very close to this one.

BELLIMURINA PARVIPLICIFERA Cooper, new species
Plate 222, B, figure 3; plate 223, C, figures 5, 6

Shell moderately large for the genus, wider than long and with the hinge
forming the widest part; sides rounded, somewhat oblique; surface marked by

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 857

fine costellae undulating over interrupted wrinkles that give the surface a fine
dictyate appearance. Pedicle valve slightly convex in lateral profile; broadly and
gently convex in anterior profile; margin narrowly geniculated toward the
brachial valve to produce a short trail.

Brachial valve gently convex in both profiles; anterior and lateral margin
marked by a narrow concave rim corresponding to the anterior geniculation.
Interior with delicate cardinalia, the cardinal process small and stout, the median
ridge narrow and extending for about one-third the length.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (pedicle valve)..... 11.6 ? 18.0 19.7 1.5?
Paratype (brachial valve).... ? 12.2 17.4 15.0 ?

Types.—Holotype: 117652; figured paratype: 117651.

Horizon and locality.—Lebanon formation in Tennessee: On U. S. Highway
41, 9.6 miles southeast of Murfreesboro, Rutherford County; Columbia, Maury
County.

Discussion.—This species is known from two specimens only, but the charac-
teristics are strong. It is similar to B. charlottae in the type of ornamentation,
but the wrinkling is much finer, the visceral disk region somewhat longer, and
the geniculation more modest and producing a short trail, less steep than that of
the Minnesota species.

BELLIMURINA SUBQUADRATA Cooper, new species
Plate 222, H, figures 15-18

Shell of about average size for the genus, with the hinge forming the greatest
shell width and the cardinal extremities slightly alate. Sides nearly straight,
oblique ; anterior margin broadly rounded. Entire surface marked by irregular
and zigzag wrinkles except at the hinge where 4 or 5 subparallel oblique wrinkles
appear. Fine costellae cover the entire surface.

Pedicle valve slightly convex in lateral and anterior profiles; umbo slightly
convex and without wrinkles; median region slightly swollen; valve sloping
gently from the median region to the margins ; not geniculate at the front. Muscle
field large and subcircular in outline.

Brachial valve gently convex in profile with the most convex part slightly
anterior to the middle. A slight median depression extended from the umbo
to the anterior margin. On each side of this and in the front half the valve is
slightly swollen.

Measurements in mm.—

Hing
Length Width side Thickness
Holotype (pedicle valve) ........... 6.7 7.8 9.6 ?
Paratype (brachial valve 117655b)... 7.1 9.9 10.6 ?

Types.—Holotype: 117655a; figured paratypes: 117655b-d; unfigured para-
type: 117655¢e.

858 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality —Bromide formation (Mountain Lake member) in Okla-
homa: Slightly north of the middle of sec. 32, T. 2 S., R. 2 E., 2 to 3 miles
northeast of Springer, Carter County.

Discussion.—This species is characterized by the strength and variety of its
wrinkling. The marginal regions are characterized by stronger wrinkling than
in the umbonal and median regions. Some of the wrinkles are chevron shaped
so that the ornamentation suggests that of Ptychoglyptus. No other species is
marked like this one. Under B. concentrica a brief comparison is made to this
species, but the Pierce form has much stronger and more regularly concentric
wrinkles in the marginal zone.

A fragmentary pedicle interior shows that this species attains a size greater
than the figured types. This specimen has a length of 11 mm. and the width is
indicated as 14 mm. The specimen shows no signs of geniculation at this length.

BELLIMURINA SULCATA Cooper, new species
Plate 223, A, figures 1-3

Shell of about medium size for the genus, slightly longer than wide; hinge
about equal to the width at the middle; sides gently rounded; anterior margin
somewhat narrowly rounded. Surface marked by small irregular wrinkles on
the visceral region and fine costellae that cover wrinkles and trail.

Pedicle valve unevenly convex, the posterior half flattened and the anterior
half convex; maximum depth located just anterior to the middle; anterior pro-
file broadly and moderately domed. Visceral region separated from trail by a
narrow, shallow groove. Trail anterior to groove long, convex, and with a steep
anterior slope.

Measurements in mm.—Holotype, length 11.5, midwidth 13.9, hinge width
13.0, thickness 2.7.

Type.—Holotype: 117654.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion—This is a fairly convex form and unlike most members of the
genus is marked by a long and prominent trail. The visceral region is sepa-
rated from the trail by a shallow sulcus; the trail extends from the anterior rim
of the sulcus. This species differs from all other Bellimurinas in the features
named and in the long convex trail. The features described are suggestive of
Limbimurina, but the curved sulcus anterior to the visceral disk is not so deep
and the strong element of geniculation toward the pedicle valve is not developed.

BELLIMURINA sp. 1
Plate 222, D, figure 5

This is a moderately convex species known only from the pedicle valve. It is
characterized by irregular wrinkles and a slight anterior peripheral depression.

Measurements in mm.—117657<a, length 11.0, width 12.6.

Figured specimen.—117657a.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 859

Horizon and locality.—“Ottosee” (=Benbolt?) formation in Virginia: On
U. S. Highway 19, 25 miles west of Paint Lick, Tazewell (15’) Quadrangle.

BELLIMURINA sp. 2
Plate 222, F, figure 10

This is a fairly well preserved brachial interior showing the cardinalia, two
adductor ridges, and a short median ridge. The specimen is thought to be from
the Wardell formation, and its locality is 2 miles west of Rye Cove, Clinchport
(T.V.A. 188-NW) Quadrangle, Virginia.

Figured specimen.—Columbia Univ. 25873.

Family CHRISTIANIIDAE A. Williams, 1953

Smooth or finely costellate Strophomenacea having 4 prominent septa in the
brachial valve.

Genus CHRISTIANIA Hall and Clarke, 1892
Christiania Hatt and Crarke, Pal. New York, vol. 8, pt. 1, p. 208, 1802.

Shells subquadrate to longitudinally subrectangular with the hinge wider or
narrower than the width at the middle; pedicle valve strongly convex; brachial
valve more or less deeply concave. Surface marked by fine concentric lines,
rarely by fine costellae, and fine growth undulations.

Pedicle valve: Interarea longer than the brachial one, curved; delthyrium
more or less closed by an elevated, convex pseudodeltidium; foramen small, lo-
cated at the beak and cutting the beak and the extreme apex of the pseudo-
deltidium as in the true Strophomenoidea.

Teeth moderately small, wide, and short and with small fossettes. Dental plates
nearly obsolete, usually visible as stout ridges under the teeth. Diductor im-
pressions linguate, confined to the delthyrial cavity which is very deep because
of the strongly swollen umbo. Adjustor scars small, somewhat triangular and
situated just under the dental plates. Adductor scars small and located at the
posterior of the muscle field just in front of the foramen. Diductor impressions
surrounding the adductors anteriorly and separated from one another by a more
or less well defined median ridge. Major pallial trunks extending from the an-
terior end of the diductor scars directly anteriorly. About a third the length
from the anterior margin these trunks branching and sending secondary trunks
in an anteromedian direction. Further branching into tertiary and quaternary
sinuses taking place near the anterior margin.

Brachial valve: Brachial interarea twisted into a hypercline position and much
shorter than that of the pedicle valve. Chilidium strongly convex and well cover-
ing the posterior and brachial face of the cardinal process. Brachiophores widely
divergent, moderately long, having the form of a flattened rod with an acute free
extremity ; brachiophores supported by shell substance deposited on their inner
faces. Sockets wide and shallow, partially formed by the sloping outer face of

860 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the brachiophore. Cardinal process bipartite; shafts short, stout, attached to
floor of valve; myophores with 2 or more ridges.

Interior of brachial valve divided into unequal parts, a posterior portion oc-
cupying about one-third the length and an anterior portion occupying the re-
mainder. Posterior third including the adductor field usually bent at an angle
to the anterior portion which probably carried the lophophore. In front of the
shafts of the cardinal process 2 ridges originate and extend anteriorly, rising to
a crest at the point of geniculation between the anterior and posterior portions
of the valve. From the point of geniculation these ridges extend almost to the
margin, then curve laterally by a narrow loop and swing posteriorly. At the
geniculation they again rise to a crest and extend posteriorly to end under the
brachiophores. These ridges are strongly elevated where they bound the adduc-
tor field. At the line of geniculation more or less prominent callosities are de-
veloped in front of the anterior adductor impressions. In some specimens these
callosities may be produced into projecting processes. The adductor scars are
obliquely placed, the anterior pair lying in the anteromedian corner of the field
and the other pair outside in the posterolateral corner.

Genotype—Laptaena subquadrata Hall, 2d Ann. Rep., New York State
Geol., pl. 46, figs. 32, 33, 1883.

Discussion.—This genus has not lately been subjected to a careful study. The
result is that a number of species have been placed in it that do not belong.
Christiania lamellosa Bassler from the Oranda formation of Virginia and Penn-
sylvania and C. youngiana (Davidson) from the Stinchar limestone of the Girvan
District, Scotland, must be excluded. These two species have been removed to
the genus Bimuria Ulrich and Cooper.

CHRISTIANIA AURICULATA Cooper, new species
Plate 215, D, figure 13; plate 215, F, figures 20-28

Christiania trentonensis brevis Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 109, pl. 95,
figs. 2, 3 (not 1 = Bimuria lamellosa), 1942.
C. cf. C. trentonensis Butts (not Ruedemann), idem, figs. 4-6.

Shell of about usual size for the genus, longer than wide; elongate, subrec-
tangular in outline with the sides usually somewhat concave inward or sub-
parallel. Anterior margin narrowly rounded to subnasute; hinge usually as
wide as or slightly wider than the midwidth. Cardinal extremities moderately
auriculate. Surface marked by more or less regular concentric growth lines.

Pedicle valve strongly convex in lateral profile with the maximum curvature
located at the umbo; anterior profile narrowly convex and with precipitous sides.
Umbo strongly swollen and protruding posterior to the posterior margin ; median
region strongly but narrowly swollen; sides nearly vertical; interarea long;
anacline. Pseudodeltidium short, wide, and strongly convex.

Brachial valve narrowly and deeply concave, most concave near the middle;
sides and anterior margins strongly bent toward the brachial direction ; interior
with strong ridges; adductor field bordered anteriorly by a strong, transverse
ridge. Cardinal process moderately large.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 861

Measurements in mm.—

Brachial Hinge )
Length length Midwidth width Thickness Height
FHOLOLY PEs sites So sishe soe 15.0 II.9 90.3 9.4 4.3 7.4
Paratype (97536a)....... 9.0 ? 9.7 10.7 ? 2.2
3 (07536D)) =)... ive 10.5 ? 9.1 9.5 ? 4.3
a CUETOOSD)).saic1-:< 13.5 10.0 9.7 0.4. 4.5 eat
a (ir) ee 16.9 13.1 Dies 10.6 ? 5.6 8.0
2 ENS 7 E Te cts 14.8 eres 10.9 10.1 3.8 7.3
EB 75724) Se 18.1 13.9 11.4 117 fy 9.6

Types——Holotype: 97537a; figured paratypes: 97537b, I11005b, 117570,
117571; figured cotype of C.t. brevis Butts: 97536b; unfigured cotype C.t. brevis
Butts: 97536a; unfigured paratypes: 97537c, I11005a, 117572a-c.

Horizon and locality—Oranda formation in Virginia: Along the railroad
4 mile west of Strasburg, Strasburg (15’) Quadrangle; 200 yards on Virginia
County Highway 616, southeast of U. S. Highway 11, 3.5 miles southwest of
Mount Jackson, Mount Jackson (15’) Quadrangle ; junction of Virginia County
Highways 691 and 692, west of Lantz Mills, Edinburg (15’) Quadrangle; on
Virginia Highway 55, 0.4 mile west of U. S. Highway 11, on the north edge
of Strasburg, Strasburg (15’) Quadrangle; just east of the junction of Vir-
ginia County Highways 617=910, and 777, 4 mile north of Green Mount Church,
Broadway (15’) Quadrangle; on U. S. Highway 11, 4 mile southwest of
Tumbling Run, southwest of Strasburg, Strasburg (15’) Quadrangle; at the
dam on Shenandoah River, 14 miles N. 61° E. of Edinburg, Edinburg (15)
Quadrangle ; Bowman Farm, east side of U. S. Highway 11, 1 mile southwest
of Woodstock, Edinburg (15’) Quadrangle.

Discussion.—This species is characterized by its elongate form, somewhat con-
cave sides, presence of distinct ears on the cardinal extremities, and its consider-
able depth. It differs from C. platys in its greater depth and different shape.
From C. subquadrata it differs in generally attaining a greater size, in being
somewhat more elongate, and in having definite and fairly prominent ears on the
cardinal extremities.

A brachial interior of this species compared to the single interior known of
C. trentonensis shows general similarity, but the Oranda specimen is more con-
vex. As presently understood the European species C. tenwicincta (McCoy)
includes too wide a range of variation for accurate comparison with the Ameri-
can species. Christiania oblonga (Pander) is a much smaller and more slender
species.

CHRISTIANIA PLATYS Cooper, new species
Plate 210, D, figure 11; plate 214, B, figures 3-5; plate 215, B, figures 5-10;
plate 215, G, figure 29

Shell large and broad for the genus, subquadrate in outline and with the
length and width nearly equal; sides nearly parallel; anterior margin broadly
rounded ; hinge nearly equal to the width, slightly auriculate. Surface marked
by concentric growth lines only.

862 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve moderately convex in lateral profile and with the maximum
convexity in the umbonal region; anterior profile broadly convex with moder-
ately steep sides ; umbo swollen posterior to the posterior margin ; median region
strongly swollen; posterolateral areas slightly auriculate; posterolateral slopes
steep; anterior slope moderately steep. Interarea long. Interior unknown.

Brachial valve broadly concave, greatest concavity near the middle; sides not
strongly incurved. Interior with prominent septal ridges ; adductor field marked
by transverse plates uniting the septa about one-third the length from the beak;
cardinal process small; chilidium short.

Measurements in mm.—

Brachial Hinge Thick-
Length length Midwidth width ness Height
Holotype | buys wi seh 13.0 ? 12.9 9.8 iy 4.1
Paratype (1110IIa)... I1.0 ? 10.4 10.2 ? 3.6
i (11 T0004), 2 ce ? 12.4 12.4 10.1 ? ?

Types——Holotype: 111011b; figured paratypes: 111004, I11007, IIIOIIa,
117573, 117574; figured specimen: 117575.

Horizon and locality—Edinburg formation (Cyrtonotella zone) in Stras-
burg (15’) Quadrangle, Virginia: Small glen at the switch about 3 mile east of
Strasburg Junction; quarry 4 mile east of the railroad station at Strasburg
Junction ; south side of the road 0.2 mile east of Strasburg Junction ; Edinburg
formation, 14 miles south of Wadesville, Winchester (15’) Quadrangle.

Edinburg formation (Nidulites zone) in Strasburg (15’) Quadrangle, Vir-
ginia: 100 yards south of the Battlefield Crystal Caverns entrance on U. S. high-
way 11, Hupp Hill, 1 mile north of Strasburg; along Tumbling Run, 14 miles
southwest of Strasburg.

Little Oak formation in Alabama: 4 mile north of the bridge on U. S. High-
way 31, Pelham, Bessemer Iron District (15’) Quadrangle.

Discussion.—This species is distinguished from the others described herein by
its quadrate form and generally low convexity. The brachial valve is similar to
that of C. trentonensis in its low convexity, but it is a wider species than the
Rysedorf one. Christiania platys is quite unlike either C. tenwicincta (McCoy)
or C. oblonga (Pander).

CHRISTIANIA SUBQUADRATA (Hall)

Plate 214, C, figures 6-8; plate 214, D, figures 9-39; plate 215, C, figures 11, 12;
plate 215, E, figures 14-19; plate 221, B, figures 7-15

Leptaena subquadrata Hatt, 2d Ann. Rep., New York State Geol., pl. 46, figs. 32, 33, 1883.

Christiania subquadrata (Hall) Hatt and CLarKkE, Pal. New York, vol. 8, pt. 1, pp. 298, 351,
pl. 15, figs. 32, 33; plate 15A, fig. 36; pl. 20, figs. 18-20, 1892; 48th Ann. Rep. New York
State Mus., vol. 2, p. 351, pl. 6, figs. 13-18, 1895; 14th Ann. Rep. New York State Geol.
for 1894, p. 351, pl. 6, figs. 13-18, 1897.

Christiania trentonensis Butts (not Ruedemann), Alabama Geol. Surv., Special Rep. 14,
p. 116, pl. 26, figs. 22-24, 1926.

Variable, attaining a length of about 4 inch; elongate oval to longitudinally
subrectangular; sides subparallel to slightly divergent; anterior margin nar-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 863

rowly rounded. Valves concavo-convex. Maximum width usually in the an-
terior third. Surface marked by strong concentric lines of growth and minute,
difficultly distinguishable radial lines which cancellate the delicate lines of growth.

Pedicle valve moderately convex in lateral profile but with the umbonal region
narrowly and strongly convex; anterior profile narrowly convex and with the
sides nearly vertical or very steep and the median region narrowly rounded;
umbo swollen ; interarea long, strongly anacline; pseudodeltidium short, strongly
convex. Interior with dental plates reduced to ridges; vascula media deep and
prominent, breaking into distributaries at the anterior third.

Brachial valve deeply concave, the greatest depth located just anterior to the
umbo ; sides strongly bent toward the brachial valve, anterior less strongly bent.
Interior with flat brachiophores ; small cardinal process; median pair of ridges
strong; lateral ridges somewhat less strong.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Hypotype (117580a).... 13.2 8.8 0.4 vie 4.9 7.8
ee (117580b).... 13.6 9.5 8.6 6.6 4.5 6.7
oF (TL7550C)in. es 15.0 10.6 10.6 8.5 4.3 7.9
a (257580d))...44105:0 Tier 10.0 27, 5.0 8.0
53 (117580e).... 12.4 9.3 10.0 8.0 3.5 6.6
a (117580f) .... 11.4 9.4 9.3 GE 3.0 6.0
“ (117580g).... 8.7 7.0 oie) 6.1 25 4.8
oi (117580h).... 82 6.3 ao 6.4 2.0 3.9
*§ CVIPESOL) eo. o 50 5.3 6.8 6.9 1.3 2.7
* GIrr006))...2% 12.3 ? 8.5 Tegner ? 4.6
- K7ISOE) 622508 137 10.7 11.0 8.6 37 6.4
o (111016a).... 12.0 8.9 9.0 7.0 3.6 5.8
as (111016b).... 13.6 9.4 7.9 6.8 4.1 6.8
SY CTE 78) cic aie 10.3 7.8 8.4 8.4 4.0 6.3

Types.—Figured hypotypes: 71501, 110999a, IIIO0I3a, IIIOI5, 111016a,
I11017b, 111018a,b, 111020a-d, I1102I1a,c, 111029a, 117578, 1175709a, 117580},
123363, 123266a-g; measured specimens: 111006, I11016b, 117580a-i; figured
specimen : 117577.

Horizon and locality.—Little Oak formation in Alabama: 4 mile along High-
way 31 northeast of Pelham, Bessemer Iron District (15’) Quadrangle; 3 mile
northwest of Mosteller, St. Clair County; junction Bailey Gap and Cahaba
Valley roads, SW4SW3 sec. 13, T. 19 S., R. 2 W., 13 miles northeast of New-
hope Church, Vandiver (15’) Quadrangle.

“Lenoir” limestone in Alabama: 20 feet below the Pratt Ferry formation, 0.15
mile southeast of Pratt Ferry, Blocton (15’) Quadrangle.

Pratt Ferry formation in Alabama: Same locality as above.

Arline formation in Tennessee: At the Negro Cemetery, 4 mile northeast of
Friendsville, Concord (T.V.A. 138-SW) Quadrangle; on the southeast edge of
Friendsville and 1 mile northeast of Friendsville, Concord (T.V.A. 138-SW)
Quadrangle; 5 miles southeast of Knoxville; on Kennedy Road, 0.4 mile north-
west of Marbledale Church, Shooks Gap (T.V.A. 147-NE) Quadrangle; 1.500

864 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

feet south of mouth of Burnett Creek, Shooks Gap (T.V.A. 147-NE) Quad-
rangle.

Arline formation in Virginia: 4 mile south of McMullen switch, 4 miles south-
west of Marion, Marion (T.V.A. 218-SE) Quadrangle.

Athens formation (base) in Tennessee: Just east of the road intersection 25
miles south-southeast of Riceville, Calhoun (T.V.A. 125-SW) Quadrangle;
600 feet S. 4o° E. of the railroad-highway intersection 1 mile northeast of the
courthouse in Athens, Athens (T.V.A. 125-SE) Quadrangle; Tennessee High-
way 60, 54 miles east of Cleveland, East Cleveland (T.V.A. 131-SW) Quad-
rangle ; Craighead Creek, 4 mile north of Christiansburg, Sweetwater (T.V.A.
131-SW) Quadrangle; road along Meadow Fork, east of junction, 25 miles
northeast of Calhoun, Calhoun (T.V.A. 125-SW) Quadrangle.

Fetzer tongue in Tennessee: Bend of the road 1.3 miles south of Sevierville,
Pigeon Forge (T.V.A. 156-SE) Quadrangle.

Botetourt limestone in Tennessee: 25 miles southeast of Whitesburg, Bulls
Gap (T.V.A. 171-SE) Quadrangle.

Same in Virginia: Junction of Virginia Highways 311 and 114, 4 mile south-
west of Catawba, Salem (15’) Quadrangle; 4 miles southwest of Bland, Bland
County.

Effna-Rich Valley formations in Virginia: At Porterfield Quarry, 5 miles
east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Edinburg formation (Crytonotella zone) in Virginia: In the ravine at the
switch about § mile east of Strasburg, Strasburg (15’) Quadrangle; near the
dam on Shenandoah River, 14 miles N. 61° E. of Edinburg, Edinburg (15’)
Quadrangle.

Same formation (Nidulites zone) in Virginia: 100 yards south of Battlefield
Crystal Caverns entrance on U. S. Highway 11, Hupp Hill, 1 mile north of
Strasburg, Strasburg (15’) Quadrangle.

Youngman formation in Vermont: In Mississquoi Park, Highgate Springs,
St. Albans (15’) Quadrangle.

Discussion.—This species is characterized by its longitudinally subrectangular
outline, strongly umbonate pedicle valve, deeply concave brachial valve, and gen-
erally somewhat broadly rounded front. This species is so unlike C. platys in its
profiles and outline that further comparison is unnecessary. Its brachial valve
appears to be much more concave than that of C. trentonensis. The species is
most like C. auriculata, but it does not have as strong a development of the cardi-
nal extremities as that species, nor does it usually attain the large size of the
Oranda species. The lateral margins of C. subquadrata are never concave in-
ward and usually vary from nearly parallel to gently divergent anteriorly. The
species is thus usually wider at the front than is customary in the Oranda species.

Christiama subquadrata is a very variable species as can be seen from the
large collections from Friendsville. At this place it may often be picked up in
the dirt by the hundreds, the specimens having been washed by rain from the
residual soil resulting from decomposition of the Arline limestone. The Friends-
ville forms vary from nearly parallel sided to specimens having anteriorly diver-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 865

gent sides. These usually have a moderately to broadly rounded anterior. The
expanded front is a feature common to many of the specimens from the Little
Oak limestone of Alabama. Some specimens from that formation are more
expanded anteriorly than is usual in the variation of the species in Tennessee.
Specimens referred to C. subquadrata from the lower Edinburg formation of
Virginia are generally quite small and deep but appear to be well within the
variation of the species.

Some confusion has attended the identification of this genus and species in
the United States by the fact that Hall and Clarke incorrectly stated its occur-
rence as from the Helderberg formation of West Tennessee. These authors
added to the confusion by failing to give any indication of the enlargement of
their figures 32 and 33 on plate 15. On plate 15, figure 36, the enlargement of
the posterior of the brachial interior is indicated as X3 whereas it is actually
x4. The enlargement of the figures on plate 15 is about x 2.

CHRISTIANIA TRENTONENSIS Ruedemann
Plate 214, A, figures 1, 2

Christiania trentonensis RUEDEMANN, New York State Mus. Bull. 49, p. 21, pl. 2, figs. 2-6,
1901; Virginia Geol. Surv. Bull. 2A, pl. 3, figs. 14-16, 1900.

This species has been widely identified in the Appalachians, but it is doubtful
if any of the identifications are correct. The material on which this species was
created is too poor to make any identifications with it a certainty. Ruedemann
figures a specimen representing both valves. Examination of his figures and
casts of the specimens indicates that all the figured specimens are actually brachial
valves. Figures 2 and 3 of his plate 2 are stated to be respectively exterior and
side views of the pedicle valve. Figure 2 is clearly a brachial valve as indicated
by the straight and even hinge line. Furthermore, part of the shell is retained
where it has not been exfoliated from the mold of the concave brachial exterior.
In his description Ruedemann states: “Pedicle valve uniformly and strongly
convex; umbo slightly projecting and very narrow, beak obscure.” Figure 2
shows no slightly projecting umbo nor can it be seen in the cast. The profile
view (fig. 3) is of the mold of the concave exterior which would have consider-
able convexity.

In connection with the brachial interior one point needs attention. This is
Dr. Ruedemann’s description of denticles. No denticles such as he describes
were seen in the extensive Appalachian material available for study. The casts
of the types show several vertical lines and ridges, but these are located on the
place from which the cardinal process has been torn. These are actually not
denticles but represent the broken bases of the cardinal process. This feature is
shown clearly in figure 6. Here the cardinal process narrows to points with the
denticle on the outside. In well-preserved specimens the cardinal process con-
sists of 2 moderately expanded lobes.

Ruedemann prepared his specimens by roasting the limestone pebbles in which
they occurred and then plunging them into cold water. This treatment naturally

866 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

tears the shells apart and leaves them in too poor condition for good specific
description.

The fossils associated with C. trentonensis are those of the lower Edinburg
or Oranda. Christiania is abundant in both of these formations, but it seems
impossible to place C. trentonensis with either the Edinburg or Oranda species
of Christiania. In the absence of more detailed information about the pedicle
valve accurate comparison is impossible. The brachial interior of a single speci-
men is not adequate for specific identification of specimens taken from widely
different geographic and stratigraphic realms.

Types——Cotypes: New York State Mus.

Horizon and locality—Rysedorf conglomerate (pebbles of group 5) in New
York: Rysedorf Hill, near Albany.

CHRISTIANIA TRENTONENSIS BREVIS Butts
Plate 215, D, figure 13
Christiania trentonensis brevis Butts, Virginia Geol. Surv. Bull. 52, pt. 2, p. 100, pl. 95,
fig. 1, 1942.

This species is based on three cotypes. Two of these are young forms of
Christiania auriculata Cooper, new species, and the other is a fine brachial in-
terior of Bimuria lamellosa (Bassler). The writer here selects the latter speci-
men, 97536a (pl. 95, fig. 1), as lectotype of C. trentonensis brevis Butts. This
selection makes this species a synonym of B. lamellosa (Bassler) and clears the
way to establish C. auriculata on adult forms.

Figured specimen.—g7536b.

Family STROPHOMENIDAE King, 1846

Strophomenacea having either normal or reversed convexity of the valves and
a small foramen in the pedicle valve.

Genus KIRKINA Salmon, 1942
Kirkina Satmon, Journ. Paleont., vol. 16, No. 5, p. 509, 1942.

KIRKINA MILLARDENSIS Salmon
Kirkina millardensis SaLmon, Journ. Paleont., vol. 16, No. 5, p. 599, pl. 87, figs. 34, 35, 1942.
Types—Holotype: Columbia Univ. 25917; figured paratype: Columbia
Univ. 25918.

Horizon and locality—Pogonip group, Point of Rocks, Millard County,
Utah=Lehman formation (zone N of Hintze).

RHIPIDOMENA Cooper, new genus

(Greek rhipidos, fan; mene crescent)

Shells generally large, attaining a length of about 2 inches and a width of
nearly 23 inches; generally wider than long, usually somewhat parallel sided;

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 867

cardinal extremities subrectangular to subauriculate; convexi-concave in the
adult but concavo-convex when young; anterior commissure rectimarginate.
Surface finely costellate, strong and fine costellae alternate and appear in sev-
eral generations; entire surface covered by fine concentric fila. Pseudopunctae
finely and densely matted.

Pedicle valve with minute pedicle foramen, pseudodeltidium of moderate size
and convexity; teeth small, surface smooth or roughened, supported by callus
thickening; muscle area large, occupying about half the valve area; diductor
scars broad and flabellate ; adductor scars small, located at about the middle of
the muscle field on 2 low, subparallel ridges that extend anteriorly to about the
valve middle where the diductors end. Posterior of delthyrial cavity filled by
adventitious shell. Anterior and lateral margins with thickened inner rim.

Brachial interior with thickened notothyrial platform bearing 2 stout lobes of
the cardinal process having short shafts and flat myophore surfaces. Brachio-
phores visible as short, flat blades on the inner side of the sockets and nearly
buried by adventitious shell material. Median ridge short and low ; adductor field
marked by 4 short radiating ridges, 2 on each side of the median ridge; moder-
ately thickened rim just inside margins, but not so prominent as that of the
pedicle valve.

Genotype.—Strophomena tennesseensis Willard, Bull. Mus. Comp. Zool.,
Harvard Coll., vol. 68, No. 6, p. 285, pl. 2, figs. 17, 18, 1928.

Discussion.—This genus is characterized by gentle geniculation of the valves,
quadrate outline, and with length and width nearly equal. Most of the species
have the sides nearly parallel. Inside the pedicle valve the muscle field is very
large and flabellate, often occupying nearly half the area of the interior. The
diductors are commonly separated by 2 parallel ridges that extend from the
posterior to the anterior end of the muscle scar. The interior is also marked by
a prominent ridge inside the margin. Dental plates are absent, and no marked
thickening is laid under the dental ridges which simulates a dental plate as in
Strophomena.

The brachial valve is characterized by small and delicate cardinalia for such
large shells. The median ridge is very short, and the socket cups of adventitious
shell formed around the brachiophore are small. Two short ridges may appear
in connection with the adductors on each side of the median ridge.

Rhipidomena is an early strophomenoid which differs from Strophomena in
its external habit, having a quadrate form and modest geniculation and differing
internally in the form of the pedicle muscle region and the thick inner, sub-
peripheral rim. In Strophomena a ridge of adventitious shell generally nearly
surrounds the muscle scars, and the muscle field is proportionately smaller than
that of Rhipidomena. The brachial interiors of both genera are basically the
same.

RHIPIDOMENA FILICOSTELLATA Cooper, new species

Plate 254, B, figures 4-6

Shell of about usual size for the genus, subquadrate in outline and with the
length and width nearly equal ; hinge narrower than the greatest shell width which

868 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

is at the middle; sides gently rounded; anterior margin strongly rounded; cos-
tellae fine and delicate, 4 to a millimeter at the front margin. Costellae on pos-
terior half alternating strong and fine, as many as 7 fine costellae separating the
strong ones; anterior with costellae not distinctly differentiated.

Pedicle valve gently concave as usual in the genus; muscle region moderately
large; ridges extended anterior to dental ridges unusually short.

Brachial valve unevenly convex in lateral profile and with the posterior quar-
ter gently concave and the anterior three-quarters moderately convex ; maximum
convexity slightly anterior to the middle; anterior profile moderately and broadly
convex. Umbonal region gently concave; anterior three-quarters swollen medi-
ally; lateral slopes short and steep; anterior slope moderately long and steep;
cardinal extremities rounded and deflected in the direction of the brachial valve.

Measurements in mm.—Holotype, length 32.8, brachial length 31.0, midwidth
34.1, hinge width 27.8?, thickness ?.

Type.—Holotype: 117671a; figured paratype: 117671b.

Horizon and locality—Sevier formation in Tennessee: 1 mile by road north-
west of Big Springs, Binfield (T.V.A. 139-NE) Quadrangle.

Discussion.—This species is known from two specimens which reveal the
pedicle interior, the brachial exterior, and the interarea of the pedicle valve. The
species is most like R. tennesseensis but differs notably in its profiles. The lateral
profile of R. tennesseensis is much more convex in the region of geniculation
than the Sevier species. Furthermore, the concave or depressed region from the
brachial beak to the place of geniculation is deeper and longer in FR. tennesseensts.
This area in the Sevier species is only depressed for a short distance in the
vicinity of the umbo. The median region is marked by a broad swelling rather
than a marked geniculation. In anterior profile R. filicostellata is gently and
broadly convex, but R. tennesseensis is strongly domed.

RHIPIDOMENA MESLERI Cooper, new species

Plate 218, C, figures 8-10; plate 240, C, figures 13-17; plate 250, A, figures I-14;
plate 254, A, figures 1-3

Shell of moderate size for the genus, wider than long with the width about
14 times the length; semielliptical in outline; cardinal extremities varying from
acutely angular to obtuse depending on age, the older specimens having right
or obtuse angles. Lateral margins variable but usually straight or nearly so in
the adults. Anterior and anterolateral margins broadly rounded. Surface cov-
ered by costellae of unequal size; the larger or primary costellae are separated
by 1 to 3 finer ones. All costellae widen slightly anteriorly but in some speci-
mens tend toward uniformity in size. In 5 mm. at the front of 2 specimens, 21
and 23 costellae may be counted. Costellae are crossed by elevated fila about 11
to a millimeter at about the middle of a valve 20 mm. long.

Pedicle valve very gently to moderately concave at about the middle ; umbonal
region very gently swollen; anterior half very gently concave to nearly flat.
Cardinal extremities only slightly deflected toward the brachial valve. Lateral

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 869

portions gently concave to nearly flat. Interarea short, apsacline. Pseudo-
deltidium not strongly arched.

Brachial valve unevenly convex in lateral profile, the greatest convexity at
about the middle. From the posterior margin the valve rises moderately steeply
to the middle where it is abruptly rounded ; the anterior slope is moderately steep,
somewhat less steep than the posterior slope and is flat in profile. Lateral slopes
moderately steep. Umbo marked by a shallow, narrow sulcus equal in length to
about a fifth the length of the valve. Cardinal extremities slightly deflected. In-
terarea short.

Interior of pedicle valve with a roundly elliptical to ovate muscle field having
broad subflabellate diductor impressions and adductor impressions on a double
median ridge located posterior to the middle of the field. Callosity posterior to
muscle field not greatly thickened. Median ridge not extending anterior to the
ends of the diductor impressions. Subperipheral ridge not strongly developed.
Interior of brachial valve with moderately large cardinal process, small adductor
field, and low and short median ridge.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hielotype .Givitacveer tect. 23.0 22.4 28.8 25.9 4.6
Paratype! (1176782) 62.8099. 2. 20.7 20.0 24.2 23.0 2.8
3 (I7678h) soe Ssbks « 18.0 17.9 21.2 23.4 3.8
a (Giizley(0) aan Boi 27.0 26.3 32.1 35.2 3.5
‘ (QIZO7 5a) < dcjare si ctaets 41.4 40.7 52.0 50.4 ? 5.8
bi (UT 7O7 7) cs snctisac cr 31.1 30.0 30.5 39.0 4.9

Types.—Holotype: 117678b; figured paratypes: 117674a, 117675a, 117676,
117677, 117678a,c,f,g; unfigured paratypes: 117675b, 117678d,e,h.

Horizon and locality Lincolnshire formation (Hogskin member) in Ten-
nessee: North of Hayes’ house, Evans Ferry, Howard Quarter (T.V.A.
162-NW) Quadrangle; 0.1 mile north of the road, 0.8 mile southwest of Mount
Eager Church, Powder Springs (T.V.A. 154-SW) Quadrangle; Sally Cleve-
land Farm, 3 mile southwest of Washburn, Dutch Valley (T.V.A. 154-SE)
Quadrangle ; 0.4 mile east-northeast of Red Hill, 4 miles west-southwest of Thorn
Hill, Avondale (T.V.A. 162-SW) Quadrangle; 0.2 mile northwest up lane,
4, mile southwest of Fleanor Mill, Powell Station (T.V.A. 137-SE Quadrangle ;
southeast side of Library Hill, Dutch Valley (T.V.A. 154-SE) Quadrangle;
2 miles southwest of Hall Crossroad, Fountain City (T.V.A. 146-SW) Quad-
rangle; Beaver Creek, Maynardville (30’) Quadrangle.

Discussion.—This species is characterized by its somewhat transverse form,
which is unusual for the genus, and gentle profiles; it is thus in strong contrast
to R. tennesseensis and R. subparallela. This species differs from FR. tennes-
seensis in having its place of geniculation much nearer the brachial umbo, in the
gentleness of the geniculation which forms a low, broad, rounded swelling, and
in the low convexity and concavity of the valves. From R. subparallela the
Hogskin species differs in having a more rectangular outline, less narrowly
rounded anterior margin, more swollen umbonal and median region on the

870 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

pedicle valve, shorter and less concave umbonal region on the brachial valve, and
a less sharply geniculated brachial valve.

Rhipidomena mesleri differs strongly from R. tenuitesta in having more pro-
nounced and more strongly convex brachial valve, shorter umbonal swelling in
the pedicle valve, and more rectangular outline.

RHIPIDOMENA SUBPARALLELA Cooper, new species
Plate 251, A, figures 1-12

Shell attaining a length of slightly over an inch; wider than long and with the
hinge forming the widest part; sides subparallel, slightly excavated just anterior
to the cardinal extremities. Anterior margin narrowly rounded; profile mod-
erately convexi-concave. Finely costellate ; 3 costellae to a millimeter at the front
margin.

Pedicle valve unevenly concave in lateral profile, the posterior half gently con-
vex but the anterior half gently concave; umbonal and posterior half of the
median region gently swollen; lateral and anterior regions gently concave to
nearly flat; interarea moderately long, pseudodeltidium short.

Brachial valve nearly flat in the posterior half of the lateral profile but with
anterior half bent abruptly toward the pedicle valve and gently convex. Median
region concave ; lateral regions and anterior half gently convex and sloping mod-
erately. Interarea short.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
FIOloty per ees whe ata dabe 28 26.8 25.8 29.3 32.1 4.6
Paratype 1 (117681a))2.). »2 desu 24.8 24.2 25.6 26.8 4.0

Types.—Holotype: 117679; figured paratypes: 117680a, 117681a,b; unfigured
paratypes: 117680b, 117681c,d.

Horizon and locality—Elway formation in Tennessee: Road cut and quarry
on U. S. Highway 25W, 4.7 miles south of Clinton, Powell Station (T.V.A.
137-SE) Quadrangle.

Discussion—This species is characterized by its quadrate or subrectangular
outline, which generally creates the illusion of a shell that is longer than wide.
This species is likely to be confused only with R. tennesseensis, which it strongly
resembles. It differs from the Benbolt species in having less anterior convexity
and less pronounced geniculation.

Rhipidomena subparallela is more strongly geniculated than FR. tenuitesta as
it has a much more pronounced strophomenoid form than the Hogskin-Lincoln-
shire species.

RHIPIDOMENA TENNESSEENSIS (Willard)

Plate 252, A, figures 1-5; plate 252, B, figures 6-14; plate 253, A, figures 1-14

Strophomena tennesseensis WiLtard, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 285, pl. 2, figs. 17, 18, 1928.
S. amploides Butts, Virginia Geol. Surv. Bull. 52, pl. 87, figs. 7-12, 1942.

Shell large for the genus, varying in outline from nearly quadrate to semiellip-
tical. Cardinal extremities deflected toward the brachial valve varying from a

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 871

right angle to alate. Hinge equal to or greater than the width at the middle.
Lateral margins varying from nearly straight to oblique to greatly rounded.
Anterior margin narrowly to broadly rounded. Surface ornamented by fine
radiating costellae of 2 sizes, 1 or 2 costellae separating the larger ones. On the
lateral slopes, particularly anterior to the cardinal extremities, the costellae be-
come fairly uniform in size. Finer radii increasing in size toward the anterior
margin and tending toward uniformity in size along the margin. At the front
margin of a specimen 33 mm. long, 25 costellae may be counted in 5 mm., but
in a specimen measuring 46 mm. in length, only 16 costellae were counted in the
same distance. Entire surface covered by fine concentric fila, about 8 or 9 in a
millimeter at about the middle, becoming more crowded toward the front. Hinge
region may or may not be marked by a few oblique wrinkles.

Adult pedicle valve with posterior half gently swollen and with gentle slopes ;
anterior half moderately strongly geniculated toward the pedicle valve; genicula-
tion of lateral portions more gentle. Angle of geniculation between 105° and
130°. Beak inconspicuous ; foramen small, elongated, often at the anterior of a
short groove. Interarea moderately long, apsacline. Pseudodeltidium low and
inconspicuous.

Posterior half of brachial valve flattened, gently concave at the umbo; anterior
slope moderately steep; lateral slopes steeper than the anterior one. Umbonal
region sulcate, sulcus wide and shallow, extending nearly to middle of valve.

Interior: Muscle area of pedicle valve broadly cordate; diductor scars flabel-
late, separated by 2 low ridges. Adductor scars elongate elliptical in outline, lo-
cated somewhat posterior to the middle of the muscle area. Delthyrial chamber
filled by callus that is extended forward as far as the posterior ends of the adduc-
tor impressions.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype\(117683a)). 5 «sseeni ss ae’ 47.0 46.0 59.6 3 78
ss COS2B2DD ini: 9 cic aie wee a's 52.2 51.7 58.3 63.4 ?
a CUBS), si8ie nglorsieaasatnse 40.8 39.8 46.0 49.0 6.7
- (OBAUAA Ys wravcie ncislate oars 33.2 32.0 35.7 38.5 7.0
. CTIVOOAA coins siaisicisisuisis © 27.2 26.8 28.2 20.3 3.7
f Cu 760Ha its 24 Massed a 37.8 37.0 44.0 41.2 7.5
ni CRLF OOAT ae edie «a eertaeaty 18.9 18.1 21.0 21.0 2.3

Types——Figured hypotypes: 117682a, 117683a, 117684a, 117685, 117686,
117687, 117688, 117691a, 117692a, 117694a,b; measured hypotypes: 98202a,b,
1176948.

Horizon and locality—Benbolt formation in Tennessee: In road cuts 0.9 and
1.6 miles northeast of Heiskell, Powell Station (T.V.A. 137-SE) Quadrangle;
3 mile southwest of Mount Eager Church, Hogskin Valley, Powder Springs
(T.V.A. 154-SW) Quadrangle; Liberty Hill, north of Luttrell, Dutch Valley
(T.V.A. 154-SE) Quadrangle; 0.1 to 0.2 mile north of the road, 1.1 miles north-
east of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle; 30 feet above the
marble on the road along Little Sycamore Creek, 4 mile northeast of the west

872 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

edge of the Howard Quarter (T.V.A. 162-NW) Quadrangle; 4 mile northeast of
Halls School, behind the marble cliff, Howard Quarter (T.V.A. 162-NW) Quad-
rangle; Lone Mountain to Tazewell road, 14 miles northeast of Lone Mountain,
Tazewell (T.V.A. 154-NE) Quadrangle; 1 mile west of Lone Mountain, same
quadrangle; 200 feet above the ‘““Mosheim” at the east foot of the third ridge,
Loyston Pike toward Maynardville; Raccoon Valley just east of Edgemoor, 3.1
miles southwest of Claxton, Clinton (T.V.A. 137-SW) Quadrangle ; 4 mile west
of Dodson Creek on the road from Acuff to Tennessee Highway 33, Powder
Springs (T.V.A. 154-SW) Quadrangle; west side, 1 mile from crest of Mis-
sionary Ridge, Chattanooga, Chattanooga (30’) Quadrangle.

Same formation in Virginia: At Rye Cove and vicinity, Clinchport (T.V.A.
188-NW) Quadrangle; Virginia Highway 71 between Mason’s store and Dick-
ensonville, Hansonville (T.V.A. 205-SW) Quadrangle; 0.2 mile southwest of
New Bethel Church, 4 mile east of the junction of Virginia Highway 74 and
U. S. Highway 54, Hilton (T.V.A. 197-NW) Quadrangle; Fugates Hill 2 miles
N. 54° W. of Mendota, Bristol (30’) Quadrangle; 1 mile southeast of Hanson-
ville, Brumley (T.V.A. 205-SE) Quadrangle; 4 miles east-northeast of Gate
City, Gate City (T.V.A. 188-NE) Quadrangle; 4 mile southeast of Green Val-
ley Church, Brumley (T.V.A. 205-SE) Quadrangle; south side of Mount Hagan
School, Hilton (T.V.A. 197-NW) Quadrangle ; 0.2 mile south of the middle fork
of Moccasin Creek, 13 miles due south of Hansonville, Hansonville (T.V.A.
205-SW) ; 4 mile northeast of Speers Ferry, Clinchport (T.V.A. 188-NW)
Quadrangle; north of Copper Creek bridge, 14 miles southeast of Nicklesville,
Bristol (30’) Quadrangle; north side of Virginia Highway 74, 4 mile west of
Mount Hagan School, Hilton (T.V.A. 197-NW) Quadrangle; 3 mile east-
northeast of Cedar Point School, Hilton (T.V.A. 197-NW) Quadrangle.

Discussion.—This species is often abundant in the Benbolt and is an excellent
guide to that formation. The species is variable, but generally it is nearly square
to subrectangular and is fairly strongly geniculated. It is the most strongly
geniculated known member of this genus. The abrupt swelling of the anterior
about two-thirds the length from the beak is a well-marked characteristic. The
species varies considerably in size, and the larger the individual becomes, the
more it increases its width.

The only known species close to FR. tennesseensis are R. filicostellata and
R. subparallela. From the former R. tennesseesis may be distinguished by its
stronger geniculation and deeper brachial umbonal region. From the latter it
differs in stronger geniculation, less deeply concave brachial umbo, and genicula-
tion taking place nearer the brachial umbo.

RHIPIDOMENA TENUITESTA (Willard)
Plate 251, B, figures 13-17; plate 251, C, figure 18
Strophomena tenuitesta WILLARD, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 287,
pl. 2, figs. 15, 16, 1928.

Shell large, width slightly greater than the length; greatest width anterior to
the hinge; sides gently rounded; anterior margin strongly rounded; surface
marked by alternating costellae, 2 to 4 to the millimeter at the front margin.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 873

Pedicle valve unevenly convex in lateral profile, the posterior third gently
convex, the anterior two-thirds nearly flat; anterior profile broadly but gently
convex and with the median region somewhat humped; umbonal region and
median third gently swollen to form a low but perceptible median fold, visible
nearly to the front margin. Flanks long and gently sloping; anterior slope long
and gentle; interarea moderately long, gently apsacline. Pseudodeltidium small
and wide. Muscle field nearly circular, large; subperipheral rim narrow and
elevated.

Brachial valve nearly flat in lateral profile but with the posterior third flat and
the anterior two-thirds gently convex; anterior profile broadly and slightly con-
vex; umbo and median posterior third gently concave; flanks and anteromedian
two-thirds flat or perceptibly convex. Interior unknown.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Eigpotype. (1170078)... <»...» -- 41.7 ? 45.1 49.2 ? ?
‘i (TI7607D) ee oe 36.6 35.4 43.5 ? 6.8
e (TE7GOR) L OTEIO. 3 45.4 ? 50.3 47.0? ?

Types.—Figured hypotypes: 117695c, 117696, 117697,b.

Horizon and locality—Lincolnshire formation (Hogskin member) in Ten-
nessee: At Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle; Evans
Ferry section, U. S. Highway 25E, north of Indian Creek, Howard Quarter
(T.V.A. 162-NW) Quadrangle.

Lincolnshire formation in Tennessee: 4 mile north and northwest of Eidson,
Kyles Ford (170-SE) Quadrangle.

Same formation in Virginia: At Clinchport, Clinchport (T.V.A. 188-NW)
Quadrangle ; Speers Ferry, Clinchport (T.V.A. 188-NW) Quadrangle; on U. S.
Highway 19, 0.3 mile east-southeast of Hansonville Post Office, Hansonville
(T.V.A. 205-SW) Quadrangle; north of Copper Creek on the railroad between
Speers Ferry and Clinchport, Clinchport (T.V.A. 188-NW Quadrangle.

Discussion.—This is a large species characterized by its gentle curves in lateral
profile, the swollen umbonal region, and moderately strong costellae. It is clos-
est to R. tennesseensis but is readily distinguished by its depressed form and
different proportions, the length and width being nearly equal. It is a larger
species than R. subparallela but is not so strongly convex in the anterior part
of the brachial valve as that species.

RHIPIDOMENA sp. 1
Plate 213, D, figures 23, 24; plate 248, B, figures 2, 3

Three imperfect specimens are the only trace of this genus yet to be taken
from the Arline formation. These indicate a subquadrate species of low con-
vexity and concavity. The posterior half of the pedicle valve is convex and the
anterior half very gently concave. The umbo is fairly strongly swollen, but the
swelling dies down at the middle of the valve. The umbo of the brachial valve
is marked by a narrow, shallow sulcus that extends to about the middle of the
valve. The posterior third of the brachial valve is somewhat flattened, but the

874 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

remainder is gently convex. The surface is marked by fairly strong costellae,
about 15 in 5 mm. at the anterior margin. Fine costellae alternate with several
of the stronger ones.

Measurements in mm.—117699a, length 23.9, brachial length 22.5, midwidth
(based on half-width) 27.4, thickness 4.9.

Figured specimens.—117698, 117699a.

Horizon and locality—Arline formation in Tennessee: About 100 feet below
the top in the glade 4 mile southeast of Friendsville, Concord (T.V.A. 138-SW)
Quadrangle.

Discussion—The specimens are not like any described species.

Genus TRIGRAMMARIA Wilson, 1945

Trigrammaria Wixson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 140, 1945; Geol.
Surv. Canada, Bull. 8, p. 108, 1946.

The description by Dr. Wilson is as follows: “The species and its varieties,
like Strophomena have a resupinate pedicle valve, concave anteriorly, and a
convex brachial valve. They are triangular in outline; the brachial valve being
more or less sharply geniculate with a broad anterior fold prolonged beyond the
general contour, and a corresponding sinus in the pedicle valve; a small pedicle
muscle scar and three septa in the brachial valve ; the median septum is prolonged
and two lateral ones added, both curving inward towards the median septum;
pseudopunctae forming a fine irregular network.

“The genotype of Strophomena, S. rugosa cannot now be examined. The
first Strophomena described and illustrated from North America was Producta
incurvata Shepard, 1838, now recognized as S. filitexta Hall. This species illus-
trates the typical form, the deeply sculptured pedicle muscle scar and a single
strong median septum, and the radial arrangement of the punctae, and it is here
regarded as typical of the genus Strophomena.

“Several score of S. filitexta were examined, none of them complete, but all
showed one stout median septum or its impression. Trigrammaria differs, then,
from Strophomena in having three septa in the brachial valve, in its small pedicle
muscle scar, and in the irregular network arrangement of the [pseudo] punctae.
It differs from the following genus Microtrypa in being triangular in outline and
in being convex and more or less geniculate. In addition, the median septum of
Microtrypa divides anteriorly making 4 septa in all.

“The name is derived from tria (three) and gramme (a line) and refers to
the three fine septa.”

Strophomena winchelli Hall and Clarke is referred to this genus because of
the brachial folding and triseptate interior of the brachial valve.

TRIGRAMMARIA TRIGONALIS PRIMA Wilson
Trigrammaria trigonalis prima Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4,
p. 143, pl. 2, figs. 3, 4, 1945; Geol. Surv. Canada, Bull. 8, p. 110, pl. 10, fig. 20, 1946.
Type.—Holotype: G.S.C. 7658.
Horizon and locality—Chaumont formation in Quebec; La petite Chaudieére,
west of Hull.

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 875

TRIGRAMMARIA WILSONAE Cooper, new species
Plate 263, B, figures 10-16

Shell of about medium size for the genus, subrectangular in outline; wider
than long and with the hinge narrower than the width at the middle; sides gently
rounded ; anterior margin subnasute; anterior commissure narrowly uniplicate ;
surface finely costellate, strong costellae alternating with up to 4 fine costellae.

Pedicle valve uneven in lateral contour, the umbonal region gently convex but
the anterior three-fourths gently concave; anterior profile broadly and gently
concave; umbonal region gently convex; median region marked by a shallow
and narrow sulcus that deepens toward the anterior margin; flanks bounding
sulcus gently concave; sides slightly bent in the direction of the pedicle valve.

Brachial valve gently convex in lateral profile and with the maximum con-
vexity at about the middle; anterior profile broadly and moderately convex;
beak marked by a smooth swollen spot; umbo marked by a shallow, narrow sul-
cus that disappears at about the valve middle; median region swollen, the swell-
ing extending to the lateral slopes which are short and steep; median fold origi-
nating just anterior to the middle, narrowly rounded.

Measurements in mm.—Holotype, length, 14.3, brachial length 13.9, midwidth
16.9, hinge width 14.9, thickness 4.5, height 4.7.

Type.—Holotype: 117753.

Horizon and locality —Rockland formation (Napanee member) in New York:
From a road cut on the east side of New York Highway 12 on the south side of
Sugar River, 44 miles south-southeast of Port Leyden, Port Leyden (15’)
Quadrangle.

TRIGRAMMARIA WINCHELLI (Hall and Clarke)
Plate 263, A, figures 1-9

Strophomena winchelli HAtt and CLarKkE, Pal. New York, vol. 8, pt. 1, p. 344, pl. 9, figs. 10,
12-14, 1892—-WINCHELL and SCHUCHERT, Geol. Minnesota, vol. 3, pt. 1, p. 394, pl. 31,
fig. 11, 1895. Hatt and CrarkE, 48th Rep. New York State Mus., vol. 2, 1895, p. 344,
pl. 4, figs. 31-33, 1805; 14th Rep. State Geol. New York for 1804, p. 344, pl. 4, figs. 31-33,
1897.—RaascH in SHROCK and Raascu, Amer. Midland Nat., vol. 18, No. 4, p. 492,
pl. 4, fig. 10, 1937.

Types —Figured hypotypes: 117752a,b, 123280.

Horizon and locality.—Platteville formation (McGregor member) in Minne-
sota, Wisconsin, and Illinois.

FURCITELLA Cooper, new genus
(Latin furca, fork)

Shells small, attaining a width of about 0.8 inch; generally wider than long;
subrectangular in outline, with the hinge generally equal to or slightly less than
the midwidth. Biconvex, but the valves unequal in convexity, the brachial valve
having the greater convexity and the pedicle valve usually flattened to somewhat
concave in the anterior half. Surface costellate, costellae subequal. Foramen
large; pseudodeltidium strongly convex. Pseudopunctate.

876 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Interior of pedicle valve with large, stout teeth, short but stout dental plates ;
muscle field moderately large, subcircular, surrounded by a thin to moderately
thick extension from the dental plates that nearly surrounds the area. Diductor
scars crescentic, large; adductor scars small, divided by a short median ridge;
no pallial marks preserved in specimens available.

Interior of brachial valve with short, stout cardinal process, convex chilidium,
and moderately thickened notothyrial platform ; brachiophores thin and bladelike,
supported by cups of adventitious shell; median ridge short and low, bifurcating
anteriorly ; adductor scars elongate, separated by an oblique ridge on each side
of the median ridge. Pallial sinuses consisting of 4 parallel trunks extending
directly anterior to the adductor field.

Genotype—Furcitella plicata Cooper, new species.

Discussion.—This genus is characterized by its fairly strong and even costellae,
the compressed biconvex form with only the anterior of the pedicle valve flat-
tened to concave; fairly large foramen; rounded muscle scar in the pedicle valve
surrounded by extensions from the dental plates ; short dental plates ; strophome-
noid cardinalia but with median ridge forked at the front and with an oblique
lateral ridge on each side of it.

Unlike Strophomena the genus Furcitella appears to have definite dental
plates. These appear in young specimens in which the margins of the muscle
area not yet thickened. Close examination of such specimens shows that the den-
tal plate is directly under the dental ridge and not offset from it. The structures
have exactly the appearance of the receding dental plate so characteristic of the
orthids.

The members of this genus have been previously assigned to Holtedahlina of
Foerste. The external resemblance between the two genera is very close. Holte-
dahlina is characterized by a compressed biconvex profile, large foramen, sub-
equal and strong costellae but the interior is essentially that of Strophomena.
Inside the brachial valve of Holtedahlina the median ridge does not bifurcate as
in Furcitella, but 2 ridges arise on each side of it near its anterior end. This
arrangement simulates bifurcation but is certainly not the same.

Two other described genera are close to Furcitella: Opikinella Wilson and
Microtrypa Wilson. The first of these genera is based on two brachial valves
representing two species O. affinis Wilson and O. salmoni Wilson. This genus
is characterized by its author as having an unusual septal system. “Three ridges
lie between the brachiophores. The central ridge divides at a short distance from
the beak, and the four continue for more than half the distance to the anterior
margin, the central pair being longer than the lateral pair.”

The writer has examined casts of these two specimens kindly provided by
authorities of the Geological Survey of Canada. Examination indicates that the
median ridge does not divide but that the 2 lateral ridges are implanted on the
sides of the median ridge near its anterior extremity. This is precisely the con-
dition that takes place in the septal arrangement of the high Middle and Upper
Ordovician strophomenas. Accordingly the writer believes that Opikinella is
a synonym of Strophomena and has so placed it in this monograph.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 877

The septal arrangement of Microtrypa is quite different from that of Opikinella
but is similar to that of Furcitella. The generic description of Microtrypa indi-
cates that “Microtrypa is semicircular or subtriangular in outline; has a low
evenly convex brachial and a resupinate pedicle valve, concave on the anterior
part ; a small round pedicle muscle scar and four septa in the brachial valve. The
median septum is forked anteriorly and two laterals added, which do not curve
as in Trigrammaria. The two limbs of the bifurcated median septum are sub-
parallel, the two lateral septa are divergent. Thus the brachial interior arrives
at the same septal system as Opikinella of the Rafinesquina group, though the
convexity of the valve is reversed.”

Although the septal arrangements of Microtrypa and Furcitella are both char-
acterized by a bifurcated median ridge their general contours and exterior are
not the same. Microtrypa is like Strophomena in exterior details, but Furcitella
is most like Holtedahlina in ornamentation and profiles. Evidently the two
genera are members of the same family.

FURCITELLA PLICATA Cooper, new species
Plate 229, D, figures 16-26

Of about usual size for the genus, wider than long; hinge about equal to or
slightly greater than the midwidth; sides nearly straight ; anterior margin broadly
rounded ; costellae subequal, numbering 4 to 5 in a millimeter at the anterior
margin ; many specimens marked anteriorly by strong radial wrinkles or plicae.

Pedicle valve gently convex in lateral profile with the front third to half flat-
tened ; umbo and median region marked by a low, narrow fold; flanks sloping to
margins ; posterolateral and marginal regions flattened. Interior with moderate-
sized muscle area surrounded by a thin elevated rim; muscle area in length equal
to one-quarter the valve length.

Brachial valve gently convex in lateral profile and with the maximum con-
vexity located just anterior to the umbo; anterior profile broadly and gently con-
vex; umbo flattened, marked at the beak by a single costella; sulcus shallow,
obscure, disappearing near the middle; anteromedian region somewhat swollen
to form a low fold; sides slightly convex. Interior with small and delicate cardi-
nalia ; adductor field with a prominent oblique ridge on each side of the median
ridge.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Paratype (pedicle valve 117750a).. 10.7 ? 13.0 11.6 ?
id Cy i Suit EZeSE ) acy ee ? IL.5 11.8 ?
rs wf Sele MEG SOG) ais toss ? 15.5 16.2 ?
% (brachial valve 117751b). ? 9.2 10.9 11.0 ?
" (Chae s LLZ7Z50E) 2S 10.9 15.7 14.6 ?

Types.—Holotype: 117750b; figured paratypes: 117750a,c, I17751a-c; un-
figured paratypes: 117751d-g.

Horizon and locality —Oranda formation in Virginia: 0.6 mile northwest of
Linville Station, Broadway (15’) Quadrangle.

878 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion—This is a rare species in the Oranda formation and is distin-
guished by the strong anterior radial plication. The species is similar to F. sco-
fieldi (Winchell and Schuchert) but differs in being somewhat wider, in having
somewhat finer ornamentation, more prominent development of the radial plica-
tion, and a smaller pedicle muscle area. Furcitella scofieldi has the radial plica-
tions seen in the Oranda species, but not one of the specimens in the National
Collection has this feature as strongly developed as the Virginia specimens.

FURCITELLA SCOFIELDI (Winchell and Schuchert)
Plate 229, A, figures 1-5; plate 265, C, figures 5, 6

Strophomena scofieldi WINCHELL and ScHUCHERT, Amer. Geol., vol. 9, p. 286, Apr. 1, 1892;
Geol. Minnesota, vol. 3, pt. 1, p. 398, pl. 31, figs. 18-21, 1895.

Streptorhynchus subsulcatum SArRDESON, Minnesota Acad. Nat. Sci., Bull. 3, p. 335, pl. 4,
fig. 39, Apr. 9, 1892.

This species has been well described by Winchell and Schuchert, but no men-
tion was made of the tendency of some specimens to show obscure plication
which undulates the anterior parts. Mention is made of the bifurcation of the
median ridge which is one of the distinguishing characters of this shell.

Types.—Hypotypes: 117748, 117749a,b.

Horizon and locality——Prosser formation (Zygospira and Vellamo | Clitam-
bonites|] beds) in Minnesota: At Cannon Falls, Goodhue County; Kenyon,
Goodhue County; road cut 1.2 miles east of U. S. Highway 52, on south edge of
Cannon Falls, Goodhue County; St. Paul; 11 miles southeast of Kasson, Dodge
County; County Highway O, $ mile south of U. S. Highway 14, 14 miles east
of Eyota, Olmsted County.

Genus MICROTRYPA Wilson, 1945

Microtrypa Wiuson, Trans. Roy. Soc. Canada, ser. 3, vol. 30, sec. 4, p. 144, 1945; Geol. Surv.
Canada, Bull. 8, p. 111, 1946.

Microtrypa is characterized as “semicircular or subtriangular in outline; has
a low evenly convex brachial and a resupinate pedicle valve, concave on the an-
terior part ; a small round pedicle muscle scar and four septa in the brachial valve.
The median septum is forked anteriorly and two laterals added, which do not
curve as in Trigrammaria. The two limbs of the bifurcated median septum are
subparallel, the two lateral septa are divergent. Thus the brachial interior arrives
at the same septal system as Opikinella of the Rafinesquina group, though the
convexity of the valve is reversed. The [pseudo] punctae of the intermediate
shell layer form a fine, unorganized network.

“Microtrypa differs from Trigrammaria in its low, even convexity, its general
lack of a fold in the brachial valve, and in having 4 subparallel septa in the
brachial valve instead of 3.”

Microtrypa resembles Furcitella in some details, especially in the forking of
the median ridge. Furcitella, however, is not as markedly resupinate as Micro-
irypa, indeed it is generally biconvex in profile but with the brachial umbo flat-
tened or slightly concave.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 879

MICROTRYPA ALTILIS Wilson

Microtrypa altilis Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 144, pl. 2,
figs. 10-12, 1945; Geol. Surv. Canada, Bull. 8, p. 111, pl. 10, figs. 10-12, 1946.

Type.—Holotype G.S.C. 7649.
Horizon and locality—lLeray-Chaumont formation, Stewart Quarry, Rock-
land, Ontario.

MICROTRYPA ? NASUTA Wilson

Microtrypa ? nasuta Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 30, sec. 4, p. 146, pl. 2,
figs. 13, 14, 1945; Geol. Surv. Canada, Bull. 8, p. 112, pl. 10, figs. 13, 14, 1946.

Types.—Holotype: G.S.C. 7641; paratype: G.S.C. 7641Aa.
Horizon and locahty—Rockland formation, Angegardien road, 4 miles west
of L’ Orignal, Ontario.

Genus HOLTEDAHLINA Foerste, 1924
Plate 2209, B, figures 6-8

Figures of the interior and exterior of this genus are introduced for compari-
son with Furcitella which has been confused with Holtedahlina.
Types.—Figured specimens: 117744, 117747a,b.

PLATYMENA Cooper, new genus

(Greek platys, flat; mene, crescent)

Shells attaining a width of about # inch; subrectangular in outline ; planocon-
vex to slightly concavo-convex ; hinge as wide or wider than the midwidth. Sur-
face multicostellate, costellae unequal in size, a larger one setting off one to
several finer ones. Pseudopunctae finely matted.

Pedicle valve with stout teeth, no dental plates, but a thickened rim extends
anteriorly from the dental ridge and nearly encloses the small muscle field; di-
ductor scars subflabellate ; adductor scars small, associated with a thickened ridge
on the inner sides of the diductors ; median ridge, low, short, not extending an-
terior to the anterior ends of the diductors. Valve thickened inside the margin.
Pseudodeltidium small; chilidium small.

Brachial interior with delicate bilobed cardinal process; notothyrial platform
moderately thick, prominent ; brachiophores long, slender blades enclosed by deli-
cate cups to form broad sockets; median ridge short; adductors separated by
2 oblique, low ridges on each side of the median ridge. Visceral region sur-
rounded by a thickened margin.

Genotype.—Platymena plana Cooper, new species.

Discussion.—Platymena is characterized by its planoconvex profile, the small
muscle area enclosed by strong ridges, a minute bilobed cardinal process, and
obscure median ridge. It differs from Macrocoelia and Opikina in the profiles
of the valves and the delicacy of the cardinalia. It also differs in the possession
of a broad and thickened border around the visceral region of both valves.

880 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PLATYMENA ? BELLATULA Cooper, new species
Plate 230, B, figures 11-13

Shell of medium size, attaining a width of about 3 inch; subrectangular in out-
line, with the length slightly less than the width; sides gently oblique; anterior
margin broadly rounded ; hinge forming the greatest width; cardinal extremities
acute ; surface marked by costellae unequal in size, about 3 or 4 to the millimeter
at the front margin.

Pedicle valve with lateral profile gently but unevenly convex, the most convex
part located in the posterior third; anterior profile evenly and gently convex.
Umbo narrowly convex and with short, steep umbonal slopes to the posterolateral
areas, median region gently swollen ; anterior slope long and gentle ; lateral slopes
gentle. Interarea moderately long, apsacline; foramen small.

Brachial valve very gently concave to flat in both profiles; umbo concave;
posterolateral areas gently and narrowly concave; rest of valve nearly flat.

Measurements in mm.—

Brachial Hinge .
Length length Midwidth width Thickness Height
FIGIOLyPe Mele wk see ..e. 16.1 7 19.6 20.5 28 2.8
Paratype .tonaes eo: 17.6 16.4 21.4 21.5+ 2.6 2.9

Types.—Holotype: 117758; unfigured paratype: 117757.

Horizon and locality.— Bromide formation (Pooleville member) in Oklahoma:
On Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray County; 162 feet below
the massive limestone, second dam on Spring Creek, northwest of Woodford,
Murray County.

Discussion.—The interior of this species is unknown ; consequently it is placed
in Platymena with a query. The species is about the same size as P. plana but
the sides are more oblique, the shell thickness is greater, and the interarea is
longer and has a prominent pseudodeltidium.

PLATYMENA PLANA Cooper, new species
Plate 230, A, figures 1-10; plate 266, D, figures 10-16

Shell small, planoconvex in lateral profile; slightly wider than long. Hinge
forming the widest part; cardinal extremities slightly alate. Lateral margins
nearly straight to slightly oblique. Anterior margin narrowly rounded. Orna-
mentation consisting of costellae of unequal size, the larger ones separated by I
or 2 fine costellae and all crossed by fine threadlike concentric lines. At the front
margin of a brachial valve 10 mm. in length 3 of the larger costellae occupy a
space of I mm.

Pedicle valve very slightly convex in lateral profile with the most convexity
in the posterior third and the front somewhat flattened. Umbo narrowly con-
vex and produced forward for about one-third the length as a low, narrow fold.
Front half and anterolateral portions flattened. Slopes from umbo to cardinal
extremities gentle. Interarea moderately long; pseudodeltidium short.

Brachial valve characterized by a narrow, fairly deep sulcus originating at

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 881

the beak and extending for about one-quarter the length where it is lost in the
flat shell; remainder of valve nearly flat or very slightly concave. Interarea
short.

Interior of pedicle valve with short and shallow delthyrial cavity, short, thick
teeth, short muscle field surrounded on each side by moderately strongly ele-
vated thickenings. Diductor impressions separated by a low double ridge bear-
ing the adductor impressions. Anterior and lateral third of shell strongly thick-
ened and bounding a shallow visceral area.

Brachial valve interior with slender brachiophores and delicate cardinal proc-
ess. Median ridge short, wide and low; brachiophores supported by considerable
thickening. Cardinal process consisting of two slender ridges.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Paratype CII7750d) svcicsas se 14.8 13.7 18.0 19.1 2.0?
CII ZOOC) ss ccc ssnie 14.5 13.9 17.9 ? 1.4

Types.—Holotype: 117759b; figured paratypes: 117759a,c-e, 117760a-d.

Horizon and locality—Middle and upper Arline formation in Tennessee:
Glade 4 mile southeast of Friendsville ; 100 yards southwest of Negro Cemetery,
4 mile northeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle; 5 miles
southeast of Knoxville; and 1,500 feet south of the mouth of Burnett Creek,
Shooks Gap (T.V.A. 147-NE) Quadrangle; McMullens, Meadow (T.V.A.
139-NW) Quadrangle.

Discussion.—This species is compared with P. ? bellatula under the discussion
of that species. No other species of the genus is now known. Platymena is
common in the Arline formation in the Friendsville area. It occurs also in nodu-
lar limestones of the contemporaneous Athens formation.

GLYPTOMENA Cooper, new genus

(Greek glyptos, engraved; mene, crescent)

Shells generally subrectangular in outline, wider than long and attaining a
width of an inch or more. Concavo-convex in profile; surface beautifully costel-
late, larger costellae setting off groups of numerous finer costellae; whole sur-
face crossed by fine fila. Pseudopunctae forming a dense mat.

Pedicle valve with small, narrowly convex pseudodeltidium ; foramen present,
minute. Interior with short, oblique dental plates with narrow umbonal cavities.
Muscle field small, subcircular in outline and with the anterior ends of the diduc-
tors separated by a low ridge.

Brachial interior with narrow-lobed, short-shafted, bilobed cardinal process
mounting a low notothyrial platform; brachiophores long, thin, flat, obliquely
placed blades supported by swelling of notothyrial platform; median ridge short
and low ; adductor scars small; adductor and accessory septa appearing as rem-
nants only, usually absent. Subperipheral rim, low, not greatly thickened, usu-
ally somewhat beaded.

Genotype—Glyptomena sculpturata Cooper, new species.

882 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion.—This genus suggests Macrocoelia, Platymena, or Opikina. The
nature of the pseudopunctae is like that of each of these genera, but exterior and
interior details will serve to distinguish them.

Glyptomena differs from Macrocoelia externally in the presence of a well-
marked foramen, the well-developed pseudodeltidium, and the zonated character
of the ornamentation. Inside the pedicle valve the muscle field is small and the
diductors are marked by a single median ridge only ; in the brachial valve Glypto-
mena has a modest development of the median ridge and scarcely any trace of
the 5 accessory septa which mark Macrocoelia.

Platymena is like Glyptomena inside the brachial valve, but the flat brachial
valve makes an easy mark of distinction. This flatness of the brachial valve leads
to other internal differences. The visceral region of Platymena is depressed be-
low the somewhat thickened marginal region.

Opikina can be readily distinguished from Glyptomena externally because it is
usually more or less strongly geniculated and its ornamentation is not so beauti-
fully zoned as that of Glyptomena. These distinctions do not hold in all cases be-
cause some species of Opikina are not very noticeably geniculated and a few have
fairly well zoned costellae, particularly in the young stages. In spite of these
difficulties, the interior of the brachial valve of Opikina, in all known species,
has the septa strongly developed. In some instances the anterior septa are buried,
particularly the median one, but the lateral septa and adductor ridges are usually
well marked.

GLYPTOMENA ? BELLA Cooper, new species
Plate 246, A, figures I, 2

Shell fairly large, attaining a width of over an inch; subrectangular, wider than
long ; sides gently rounded, subparallel ; hinge equal to or narrower than the mid-
width; anterior margin broadly rounded; costellae well differentiated but zona-
tion narrow, 3 or 4 of the fine costellae separating the larger ones.

Pedicle valve gently and evenly convex in lateral profile; maximum convexity
near the middle; anterior profile broadly convex, the median region somewhat
narrowly humped; umbo narrowly convex to form a low fold that extends more
or less distinctly nearly to the anterior margin; median region gently swollen;
lateral slopes long and gentle; anterior slope long and gentle.

Brachial valve moderately concave in lateral profile and with the maximum
concavity at about the middle; umbo sulcate, the sulcus extended anteriorly
beyond the middle; sides and anterior margin gently curved toward the brachial
valve.

Measurements in mm.—

Brachial Hinge Thick-
Length length Midwidth width ness Height
Fidlotype ho) leh hd aS 18.7 fy 24.8 23.4 ? 2.8
Paratype (117852b).. ? 21-3 29.1 ? 31.0 ? ? ?
fe (117852c).. 20.0 ? 25.3 25.2 ? 2.6

Types.—Holotype: 1178524; figured paratype: 117852b; unfigured paratypes:
117852c,d.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 883

Horizon and locality—Murat formation in Virginia: Along the road and
ridge 2 miles northwest of Lexington, vicinity of Whistle Creek, Lexington (15’)
Quadrangle.

Discussion —Although the interior of this species is not known, it is assigned
to Glyptomena because its ornamentation is so much like that of Glyptomena.
This is a large species, the largest so far assigned to the genus. It is therefore
quite different from G. parvula and G. sculpturata which are much smaller.
Glyptomena prisca is a moderately large species, but its shape is totally different
from that of G. bella.

GLYPTOMENA ? DISTANS (Raymond)
Plate 231, B, figure 8

Rafinesquina distans RAyMonp, Ann. Carnegie Mus., vol. 3, p. 575, 1906; idem, vol. 7, No. 2,
p. 234, pl. 35, fig. 1, 1911.

The ornamentation of this species suggests that of Glyptomena rather than
Rafinesquina.

Type.—Holotype: Carnegie Mus. 5452.

Horizon and locajity—Crown Point formation in New York: At Crown
Point, Port Henry (15’) Quadrangle.

Valcour formation, in New York: On Valcour Island, Plattsburg (15’)
Quadrangle.

GLYPTOMENA ? MINGANENSIS (Twenhofel and Stiles)

Strophomena alternata Bittincs (not Conrad), Canadian Nat. Geol., vol. 4, p. 443, 1859.
Rafinesquina champlainensis minganensis Twenhofel and Stiles in TwENHOFEL, Geol. Soc.
Amer. Special Pap. 11, p. 50, pl. 8, figs. 3-6, 1938.

This species is doubtfully assigned to this genus on the basis of its ornamenta-
tion. Possibly it is the young of a Macrocoelia, but this cannot be settled until
interiors have been found or made.

Horizon and locality—Mingan formation (lower 50 to 60 feet): In the
Mingan Islands, St. Lawrence River.

GLYPTOMENA PARVULA Cooper, new species
Plate 245, A, figures 1-8

Shell small for the genus, wider than long and with the hinge forming the
widest part; sides nearly straight; anterior margin broadly rounded; surface
costellate, the stronger costellae conspicuous in a mat of finer ones, the latter
forming broad zones between the strong costellae.

Pedicle valve strongly and evenly convex in lateral profile and with the maxi-
mum convexity located at the middle; anterior profile strongly domed ; umbonal
region strongly swollen; median region inflated; lateral and anterior slopes long
and steep. Interarea fairly long. Interior with stout, nearly vertical dental plates ;
muscle field with floor somewhat thickened and in length equal to about one-
third the total shell length.

884 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve gently concave in the posterior half, deepest just anterior to
the middle and with the anterior margin moderately strongly bent toward the
brachial valve ; sides more gently deflected in the direction of the brachial valve
than the front margin. Interior with cardinalia somewhat thickened ; adductor
field triangular, thickened, with apex directed anteriorly ; adductors separated
by a low median ridge.

Measurements in mm.—

Brachial Hinge Thick-
Length length Midwidth width ness Height
Paratype (117855b).. ? 10.8 13.1 13.5 ? ?
a (117855g).. 12.0 ? 13.2 12.5 B 4.9

Types.—Holotype: 117855e; figured paratypes: 117855f-h; unfigured para-
types: 117855a-d.

Horizon and locality.—Effna-Rich Valley formations in Virginia: At the Por-
terfield Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quad-
rangle.

Discussion.—As its name implies this is a species of small size characterized
by deep concavity and squarish outline. It is most like G. sculpturata but is
smaller, more deeply concave, and with a more strongly convex pedicle valve.

GLYPTOMENA ? PRISCA (Raymond)
Plate 235, A, figure 1; plate 235, D, figures 3, 4

Strophomena prisca RayMonp, Amer. Journ. Sci., ser. 4, vol. 20, p. 369, 1905; Ann. Carnegie
Mus., vol. 7, No. 2, p. 234, pl. 35, figs. 2, 3, IQII.

The types of this little species are poorly preserved but they show clearly
that the species must have had a concavo-convex shell quite unlike that of
Strophomena. The interior of this species is not known, and the specimens in
the National Museum show none of these essential details.

The pedicle valve assigned to this species has low convexity but with the me-
dian region somewhat narrowly swollen. The lateral slopes are long and gentle.
The costellae of this valve appear somewhat more crowded than those of the
brachial valve and number 3 or 4 of the stronger ones at the front margin.

The brachial valve has a well-defined sulcus beginning at the umbo and defin-
able nearly to the anterior margin. The costellae of this valve are more definitely
zoned with 2 of the stronger costellae in 1 mm.

Measurements in mm.—

Brachial Hinge Thick-
Length length Midwidth width ness Height
Hypotype (117854a).. ? 10.6 14.0 12.4 ? ?
re (117853)... 13.9 ? 15.8 15.3 ? 1.9

Types.—Holotype: Carnegie Mus. 5464; figured hypotypes: 117853, 117854a.

Horizon and locality—Crown Point formation in New York: On Valcour
Island, Plattsburg (15’) Quadrangle.

Same formation in Vermont: On Fort Cassin and Appleton Point near Fort
Cassin, Port Henry (15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 885

Discussion.—The interior details of this species are unknown; consequently,
it is necessary to question the generic assignment which was made on the basis
of form and ornamentation. This species is somewhat suggestive of G. sculp-
turata but has a different outline, being squarer and more deeply concave.

GLYPTOMENA SCULPTURATA Cooper, new species
Plate 246, F, figures 16-23

Shell attaining a width of about 3 inch; wider than long and with the hinge
forming the widest part; sides gently rounded, oblique to subparallel; cardinal
extremities slightly acute, anterior margin broadly rounded. Strong costellae
separated by groups of smaller costellae numbering as high as 7.

Pedicle valve unevenly convex in lateral profile, the posterior two-thirds gently
convex, the anterior third fairly strongly bent toward the brachial valve; anterior
profile moderately and broadly convex; umbonal region gently swollen; median
region gently swollen; anterior and lateral slopes short and moderately steep.
Interarea short.

Brachial valve gently concave in lateral profile with the greatest concavity lo-
cated anterior to the middle; umbo concave, the concavity produced anteriorly to
form a shallow sulcus; sides and anterior margin fairly strongly bent toward
the brachial valve.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Paratype (117856e)..... 14.3 13.1 17.2 19.2 1.9 3.7
(107850b)s 2.88 14.3 12.0 13.9 14.7 ? ?

Types.—Holotype: 117856c; figured paratypes: 117856a,b,d; unfigured para-
types: 117856e,f.

Horizon and locality—Chatham Hill formation in Virginia: 1.2 miles S.
31° E. of Sharon Springs, Burkes Garden (15’) Quadrangle.

Discussion.—This species is characterized by moderate convexity and’ con-
cavity and obliquely sloping sides. It is a larger, less concave, and less convex
species than G. parvula. Its convexity is greater than that of G. ? prisca, and
its shape is somewhat more rectangular and with more sloping sides than the
Chazy species from New York.

GLYPTOMENA sp. 1
Plate 235, B, figure 2

This species is suggestive of G. ? prisca (Raymond) but is more convex and
does not have as narrowly convex an umbonal region on the pedicle valve.

Measurements in mm.—117857 a, length 12.9, midwidth 13.9, hinge width 13.6,
height 2.0.

Figured specimen.—117857a.

Horizon and locality—Ward Cove ? formation in Virginia: 4 mile south of
Rocky Gap, Pocahontas (30’) Quadrangle.

886 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genus RAFINESQUINA Hall and Clarke, 1892

Rafinesquina Hatt and CrarkeE, Pal. New York, vol. 8, pt. 1, p. 281, 1892——SatLmon, Journ.
Paleont., vol. 16, No. 5, p. 570, 1942.

RAFINESQUINA LENNOXENSIS Salmon

Rafinesquina lennoxensis SaAtMon, Journ. Paleont., vol. 16, No. 5, p. 576, pl. 85, figs. 18-20,
1942.—Witson, Geol. Surv. Canada, Bull. 8, p. 70, text fig. 1, No. 4; pl. 5, fig. 5, 1946.

Types.—Holotype: Columbia Univ. 25884; paratype: Columbia Univ. 25885.

Horizon and locality—Rockland formation (Napanee member) in Ontario,
Canada: On Selby Creek, near Napanee, Lennox and Addington County.

Same formation and member in New York: On the Sugar River south of
Port Leyden, Port Leyden (15’) Quadrangle.

RAFINESQUINA OLLIFORMIS Salmon

Rafinesquina olliformis Satmon, Journ. Paleont., vol. 16, No. 5, p. 577, pl. 85, figs. 21, 22,
1942.

Type.—Holotype: Columbia Univ. 25886.

Horizon and locality—Rockland formation (Napanee member) in Ontario,
Canada: On the Selby Road 1 mile from Napanee, Lennox and Addington
County.

RAFINESQUINA PLANULATA Cooper, new species
Plate 266, A, figures 1-4

Of about medium size for the genus, wider than long ; hinge equal to or slightly
greater than the midwidth; sides nearly straight or slightly oblique; anterior
margin broadly rounded; cardinal extremities nearly a right angle or slightly
acute. Pedicle valve marked by a median costella stronger than the others;
median region from beak to margin marked by several costellae almost as strong
as the median one; lateral areas marked by costellae of varying sizes, 1 to 4 of
the finer ones alternating with the stronger costellae.

Pedicle valve almost flat in lateral and anterior profile; beak prominent and
umbo slightly and narrowly swollen. Interior with moderately long, slender
dental ridges diverging at an angle of about 90° ; muscle area small, heart shaped.

Brachial valve very gently concave in lateral profile and with the maximum
concavity located near or posterior to the middle ; anterior third deflected slightly
toward the brachial valve but nearly flat; cardinalia delicate; median ridge and
notothyrial platform slightly thickened; cardinal process small and delicate.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (pedicle valve) ......... 11.8 ? 16.7 18.8
Paratype ( “ “ 123281g).. 16.5 ? 21.4 24.0 ?
s (brachial valve 123281k). ? £23 17.0 ? ?

«“ ( « “ pegeerel) cal, - 12.6 16.9 19.9 ?

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 887

Types.—Holotype: 123281a; figured paratypes: 123281e,f,j; unfigured para-
types : 123281b-d,g-i,k-m.

Horizon and locality—Oranda formation in Virginia: 0.6 mile northwest of
Linville Station, Broadway (15’) Quadrangle.

Discussion —This is a very small and delicate species and is the only repre-
sentative of the genus so far found in the Oranda formation. It is characterized
by its small size and the delicate character of its cardinalia. It differs from
R. trentonensis in its smaller size, planoconvex profile, and delicate cardinalia.

RAFINESQUINA PRESTONENSIS Salmon

Rafinesquina prestonensis SALMON, Journ. Paleont., vol. 16, No. 5, p. 578, pl. 85, figs. 28-33,
1942.—Witson, Geol. Surv. Canada, Bull. 8, p. 75, text fig. 4, No. 5; pl. 7, figs. 4a-c, 1946.

Type.—Holotype: Columbia Univ. 25888.
Horizon and locality—Rockland formation and Guttenberg member of the
Decorah formation in Illinois: At Milbrig.

RAFINESQUINA SINCLAIRI Salmon
Plate 266, B, figures 5-7; plate 266, C, figures 8, 9

Rafinesquina elongata SALMON (not Teichert, 1937), Journ. Paleont., vol. 16, No. 5, p. 576,
pl. 85, figs. 14-17, 1942.
R. sinclairi SaLtmon, idem, vol. 17, No. 3, p. 309, 1943.

This name is used for specimens occurring in the Guttenberg member in Wis-
consin, the probable Guttenberg in Missouri, and the Auburn chert in Missouri.
The specimens indicate a species variable in length-width relationship and in
convexity. Both of these features apparently depend on age. The name sinclairi
is used in preference to R. alternata, to which this shell is related, because the
ornamentation and cardinal extremities are more like that of the Guttenberg
species. Rafinesquina sinclairi appears to be somewhat more convex than R. alter-
nata, and the ornamentation is featured by a preponderance of closely spaced
strong costellae separated by 1 to 4 of the fine costellae.

Figured hypotypes.—117858a,b, 117859.

Horizon and locality—Auburn chert in Missouri: 4 mile east of Auburn,
Elsberry (15’) Quadrangle.

Barnhart formation in Missouri: On U. S. Highway 61, 0.1 mile south of Salt
River, north of New London, Ralls County; on U. S. Highway 61, 0.2 mile
south of Koch School, NE. corner SWiSW3$ sec. 6, T. 41 N., R. 6 E., 2 miles
south of Barnhart, Kimmswick (15’) Quadrangle.

Guttenberg member in Wisconsin: Above the 8 inches of blue clay of the
Platteville, on Wisconsin Highway 151, 0.7 mile northeast of Dickeyville, Grant
County ; NW sec. 19, T. 3 N., R. 1 W. Grant County; 2 miles west of Platte-
ville ; 0.1 mile south of the Little Platte River on Wisconsin Highway 81, 2 miles
northwest of Platteville, Mineral Point (30’) Quadrangle.

888 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

RAFINESQUINA TRENTONENSIS (Conrad)
Plate 247, B, figures 5, 6; plate 266, E, figure 17

Rafinesquina trentonensis (Conrad) Satmon, Journ. Paleont., vol. 16, No. 5, p. 574, pl. 85,
figs. I-10, 1942 (for complete synonymy).

The name FR. trentonensis has now superseded the old and familiar Rafines-
quina alternata. The latter had become almost a fixture in our Ordovician faunal
lists, but many other familiar names have fallen to nomenclatorial technicalities.
The details are explained by Dr. Eleanor Salmon in her detailed study of the
Mohawkian Rafinesquinae.

Dr. Salmon included R. hermitagensis Bassler under the synonymy of R. tren-
tonensis, but this seems to be an error. That species appears to differ in shape
and ornamentation from FR. trentonensis, and to have a less well developed in-
terior. The Hermitage species was taken in sandstone and is preserved as im-
pressions on the rock. Nevertheless, all the details of the interior and exterior
are clearly visible and seem quite distinct from the Trenton species.

Refinesquina trentonensis is identified in the Guttenberg of Illinois by Dr. Sal-
mon and in the Guttenberg of Wisconsin by other authors. The specimens in the
National Museum and ones collected by the writer in Wisconsin and Missouri
seem to belong to FR. sinclairi rather than FR. trentonensis, but some specimens
were close to the latter species. More extensive collections may in the future
show the presence of this species in Wisconsin.

In the Appalachians Rafinesquina is not well represented in the rocks covered
by this monograph. It is however found in abundance in the Collierstown forma-
tion, but the specimens available are too poor for accurate identification. They
are tentatively placed under the above heading.

Figured specimens.—97578a,b, 123282.

RAFINESQUINA in Canada

In 1946 Dr. Alice E. Wilson described many species of Rafinesquina from
the Leray-Rockland interval in the Ottawa-St. Lawrence Lowland. None of
these species has been identified in any of the National Museum collections, but
they are listed here because they must be checked in any future work on Rafines-
quina in eastern United States. The first set of figures after the name refers to
the pages and plates in the original description of most of these species in the
Transactions of the Royal Society of Canada, ser. 3, vol. 38, sec. 4, 1944; the
second set of figures refers to Geological Survey of Canada, Bulletin 8, 1946.
Rafinesquina alternata (Conrad) Wilson, 1946, p. 66, text fig. 1, No. 3; pl. 5, fig. 4.

R. alternata alata Wilson, 1944, p. 160, text fig. 2, No. 4; pl. 1, fig. 17;
1946, p. 66, text fig. 2, No. 4; pl. 5, fig. 18.
R. alternata intermedia Wilson, 1944, p. 161, text fig. 1, No. 1; pl. 1, fig. 1;
1946, p. 67, text fig. 1, No. 1; pl. 5, fig. 3.
R. alternata plana Wilson, 1944, p. 161, text fig. 1, No. 1; pl. 1, fig. 1.
1946, p. 67, text fig. 1, No. 1; pl. 5, figs. 1, 2.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 889

This species is stated to have been taken from the Lowville formation as well as from the
Leray-Rockland beds.

R. alternata platys Wilson, 1944, p. 162, text fig. 2, No. 1; pl. 1, fig. 10.
1946, p. 68, text fig. 2, No. 1; pl. 5, fig. 11.
R. alternata semiquadrata Wilson, 1944, p. 164, text fig. 2, No. 3; pl. 1, fig. 6.
1946, p. 69, text fig. 2, No. 3; pl. 5, fig. 7.
R. alternata transversa Wilson, 1944, p. 165, text fig. 1, No. 6; pl. 1, fig. 11.
1946, p. 60, text fig. 1, No. 6; pl. 5, fig. 12.
R. esmondensis borealis Wilson, 1944, p. 169, text fig. 4, No. 1; pl. 1, fig. 8.
1946, p. 72, text fig. 4, No. 1; pl. 5, fig. 9.
R. hullensis Wilson, 1944, p. 170, text fig. 4, No. 6; pl. 1, fig. 19.
1946, p. 73, text fig. 4, No. 6; pl. 5, fig. 20.
R. opeongoensis Wilson, 1944, p. 171, text fig. 5, No. 5; pl. 1, fig. 16.
1946, p. 73, text fig. 5, No. 5; pl. 5, fig. 17.
R. orleansensis Wilson, 1944, p. 171, text fig. 5, No. 6; pl. 1, fig. 13.
1946, p. 74, text fig. 5, No. 6; pl. 5, fig. 14.
R. rotunda Wilson, 1944, p. 174, text fig. 5, No. 4; pl. 1, fig. 7.
1946, p. 75, text fig. 5, No. 4; pl. 5, fig. 8.
R. subtrigonalis Wilson, 1944, p. 175, text fig. 4, No. 4; pl. 1, fig. 15.
1946, p. 76, text fig. 4, No. 4; pl. 5, fig. 16.
R. miodeltoidea Wilson, 1944, p. 179, text fig. 8, No. 2; pl. 2, fig. 9.
1946, p. 79, text fig. 8, No. 2; pl. 6, fig. 9.
R. okulitchi Wilson, 1944, p. 181, text fig. 7, No. 2; pl. 2, fig. 7.
1946, p. 80, text fig. 7, No. 2; pl. 6, fig. 7.
R. praedeltoidea Wilson, 1944, p. 183, text fig. 8, No. 3; pl. 2, fig. 11.
1946, p. 81, text fig. 8, No. 3; pl. 6, fig. 11.
R. semicircularis minor Wilson, 1944, p. 186, text fig. 6, No. 1; pl. 2, fig. 3.
1946, p. 83, text fig. 6, No. 1; pl. 6, fig. 3.

COLAPTOMENA Cooper, new genus

(Greek colapto, chisel; mene, crescent)

Shells large, attaining a length and width of nearly 2 inches; planoconvex to
perceptibly concavo-convex ; valves strongly compressed and strongly suggesting
Leptostrophia in profile and general form. Surface costellate, costellae alternat-
ing strong and fine; concentric fila strong; posterior margins marked by strong,
oblique wrinkles. Pseudopunctate, the pseudopunctae closely matted and fine.

Interior of pedicle valve with pseudodeltidium obsolete; muscle area large,
subcircular ; diductor scars subflabellate ; adductor field located in the posterior
of the muscle field, marked by 2 low ridges separated by a narrow groove; pallial
marks prominent ; vascula media splitting at the anteromedian end of the diductor
scar, splitting into 3 trunks, I extending directly toward the anterior, the second
anterolaterally, and a third directed posterolaterally.

Brachial interior with narrow, subcarinate chilidium; cardinal process large
and stout ; adductor scars located on each side of a short, rounded median ridge,
the outer scars being the larger.

Genotype.—Colaptomena lepiostrophoidea Cooper, new species.

Discussion.—This genus is most like Rafinesquina and is probably a lateral
divergence from that genus. It differs from Rafinesquina in the pedicle valve not
being marked by the single enlarged and elevated median rib so common in the

890 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Trenton rafinesquinoids. On the inside of the pedicle valve the muscle field is
large and broadly flabellate, and the pallial marks are deeply impressed.

Inside the brachial valve interesting differences appear between Colaptomena
and Rafinesquina sensu stricto. The cardinal process of Colaptomena is large
and erect whereas that of Rafinesquina is of moderate size. In Colaptomena the
adductor field is somewhat diamond shaped and moderately deeply impressed.
No adductor ridges appear, but the field is bisected by a moderately long, low,
rounded median ridge that extends posteriorly to the platform bearing the cardi-
nal process. Another important feature of the genus is the reduction of the
pseudodeltidium to disappearance. The pseudopunctae are coarse and densely
matted together as in Opikina rather than distantly arranged in rows as in
Rafinesquina.

COLAPTOMENA LEPTOSTROPHOIDEA Cooper, new species
Plate 267, A, figures 1-10

Shell large, subquadrate to subrectangular in outline; slightly wider than
long ; hinge variable, wider than the midwidth in the young, narrower than mid-
width in old adults; cardinal extremities slightly alate and pointed to rounded
obtuse ; sides subparallel; anterior margin somewhat narrowly rounded. Pedicle
valve more strongly costellate than the brachial valve, 2 large and 2 small costellae
at the front margin; brachial valve with 5 costellae in I mm.

Pedicle valve perceptibly convex in lateral profile and with the umbonal region
the most convex part; anterior profile broadly and gently convex. Umbonal
region gently swollen, the swelling continuing noticeably to about the middle;
remainder of valve nearly flat. Interarea short, only slightly longer than the
brachial one.

Brachial valve with umbo concave and posterior median region gently concave,
rest of valve gently concave or nearly flat.

Measurements in mm.—
Brachial Hinge

Length length Midwidth width Thickness Height
FIGIOEY DE fo aiack «daveb ts 42.0 4I.I 40.0 ? 3.8 (Me Me
Paratype (1177032)... ».- a7 ? 39.3 38.5 ? 3.0?
. (£17703C)... 36.2 ? 41.3 35.8 ? 207

ss (r17763a) 2% 19.3 ? 20.5 20.6 ? 1.3

Types.—Holotype: 117761; figured paratypes: 117762a,c, 117763a,b,e; un-
figured paratypes: 117762b, 117763¢c,d.

Horizon and locality—Martinsburg formation (part with Brongniartella=
Salona) in Virginia: County Road 617=910, 0.15 mile north of Green Mount
Church, Broadway (15’) Quadrangle.

Discussion.—No other species like this one is now known.

MACROCOELIA Cooper, new genus
(Greek macro, large; koilos, hollow)

Shells large, attaining a width of more than 2 inches; subrectangular in out-
line, usually wider than long; hinge variable; nearly planoconvex to strongly

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 891

concavo-convex ; surface multicostellate, costellae unequal in size and crossed by
strong concentric fila. Pseudopunctae forming a dense mat.

Interior of pedicle valve with wide and shallow delthyrial cavity ; dental plates
rudimentary to obsolete; muscle field large, subcircular, not surrounded by a
thickened ridge; diductors flabellate; adductors small, associated with 2 ridges
along the inner edges of the diductor scars; median ridge poorly developed.
Pseudodeltidium short; chilidium fully developed. Inner margin usually with
thickened rim.

Interior of brachial valve with moderately thickened notothyrial platform;
brachiophores short, flat blades partially buried in the adventitious shell material
of the socket and notothyrial platform. Median ridge short and low; adductor
field marked by an oblique, low ridge; 2 lateral ridges and 1 median ridge ap-
pear anterior to the broad median ridge attached to the notothyrial platform.
Inside the margin marked by a subperipheral thickening.

Genotype.—Macrocoelia obesa Cooper, new species.

Discussion—This is a genus including species of large-sized shells, mostly
with broadly convex profiles and without marked geniculation. Distinction be-
tween this genus and some forms of Opikina is difficult. The shell structure of
Macrocoelia is densely pseudopunctate like that of Opikina and thus quite differ-
ent from Rafinesquina to which many of these shells were hitherto referred.

In the pedicle valve the delthyrium of Macrocoelia may be unmodified by a
pseudodeltidium or only partially covered by a remnant of a pseudodeltidium.
In Opikina on the other hand the pseudodeltidium is usually well developed. The
musculature of the two genera is very similar, but that of Macrocoelia may be
somewhat larger. A difference exists between the two genera in the peripheral
rim, that of Macrocoelia being farther toward the anterior than in Opikina. This
is undoubtedly a manifestation of the lack of geniculation in Macrocoelia.

The brachial valves of Macrocoelia and Opikina are similar in plan but differ-
ent in detail. The adductor ridges are 4 in number in both genera, but those of
Macrocoelia are not strong and in most of the species are poorly developed, if at
all. The median ridge of Macrocoelia is strong, in Opikina it is weak and in old
shells generally covered up.

As here identified Macrocoeha ranges from the Crown Point formation of the
Chazyan group to the Benbolt formation. It is not an abundant fossil in any of
the formations of the Appalachians or elsewhere.

MACROCOELIA BELLA Cooper, new species
Plate 234, B, figures 6-13

Large, wider than long, with the hinge slightly narrower than the width at
the middle; sides gently rounded, subparallel to sloping gently inward; cardinal
extremities nearly a right angle; surface costellate, costellae variable. Ornamen-
tation in posterior and median portions of brachial valve consisting of low cos-
tellae of 2 sizes, the larger ones separated by 1 to 8 smaller ones and the cos-
tellae becoming more even in size anteriorly, numbering 4 to the millimeter at
the front margin. Costellae of pedicle valve less strongly differentiated and the

892 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

larger ones separated by only I or 2 of the finer ones and numbering 2 or 3 to
the millimeter at the front margin. Entire surface covered by fine fila which
cancellate the finer costellae in the posterior and median parts, especially those
of the brachial valve.

Pedicle valve somewhat variable in lateral profile, usually fairly evenly and
moderately convex and with the maximum convexity at the middle; anterior
profile moderately domed. Beak small and inconspicuous ; umbonal region gently
swollen; median region fairly strongly swollen with anterior and lateral slopes
moderately steep. Pseudodeltidium short; interarea short.

Brachial valve moderately concave in lateral profile, the maximum concavity
somewhat anterior to the middle; umbo concave; median region gently concave
to nearly flat; sides and anterior third deflected gently to moderately in the
direction of the brachial valve. Chilidium large and convex. Interior with long-
shafted, erect cardinal process lobes, slightly thickened notothyrial platform,
shallow sockets, and subdued adductor ridges.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype ¢ is. 2 os ames 38.4 36.4 44.7 42.5 8.4
Paratype (117764)... 30.6 36.9 48.0 ? 6.3

Types.—Holotype: 117766a; figured paratypes: 117764, 117765; unfigured
paratypes: 117766b.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: From the top of the green shale on the east side of the cut on Oklahoma
Highway 18, 1.8 miles south of Sulphur, Murray County; 4 miles south of
Davis, Murray County; Valcourea zone on Spring Creek, N} sec. 17, T. 2 S.,
R. 1 W., Murray County; Sowerbyites bed, same as preceding; west Spring
Creek, east of Pooleville, Murray County; west of Nebo store, sec. 22, T. 2 S.,
R. 3 E., Murray County; middle of the east line of sec. 33, T. 2 S., R. 2 E.,
2 miles northeast of Springer, Carter County ; + mile west of U. S. Highway 77,
sec,; 25, 1.2 5,.,.R.1, E., ‘Carter, County.

Discussion——This species is characterized by large size, strong convexity,
particularly in the anterior half, and moderately strong ornamentation. Of de-
scribed species it is most like M. obesa of the Arline formation of Tennessee. It
differs however in the lateral profile of the pedicle valve which is more evenly
convex in the Tennessee species, in a less concave brachial valve and somewhat
stronger ornamentation. The profile of M. bella is also less regular than that of
M. champlainensis.

MACROCOELIA CHAMPLAINENSIS (Raymond)

Rafinesquina champlainensis RaAymMonp, Bull. Amer. Paleont., vol. 3, p. 37, pl. 18, figs. 5, 6,
1902; Ann. Carnegie Mus., vol. 7, No. 2, p. 233, figs. 6-9, III.

Horizon and locality—Crown Point formation in New York: At Crown
Point, Chazy, Valcour Island, Plattsburg (15’) Quadrangle.

Same formation in Vermont: On Isle la Motte, Plattsburg (15’) Quadrangle ;
South Hero, Rouses Point (15’) Quadrangle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 893

MACROCOELIA DUPLISTRIATA (Willard)
Plate 173, F, figure 31; plate 236, B, figures 8-12; plate 249, B, figures 10-12

Rafinesquina duplistriata Wrttarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 281, 1928.

Willard designated two specimens as cotypes. One of these is a pedicle valve
showing the exterior and preserving the profile. The other is an interior of a
brachial valve showing the subperipheral thickening and the 5 ridges associated
with the adductor field. Inasmuch as the specific characters chiefly appear on the
exterior of these shells, pedicle valve M.C.Z. 8621 is chosen as lectotype for the
species.

Evidence in the National Collection indicates that this species attained a large
size. One large brachial interior has a width of 70 mm. The species seems to
be variable in lateral profile.

Figured hypotypes.—117767, 117768, 117769, 117770, 117771.

Horizon and locality—Lincolnshire formation in Virginia: Near Goodwins
Ferry on New River, Giles County ; Speers Ferry, Clinchport (T.V.A. 188-NW)
Quadrangle.

Same horizon in Tennessee: 4 mile north of Eidson, Kyles Ford (T.V.A.
170-SE) Quadrangle.

Lincolnshire formation (Hogskin member) in Tennessee: 0.4 mile northeast
of Red Hill, 44 miles west-southwest of Thorn Hill, Avondale (T.V.A. 162-SW)
Quadrangle; on U. S. Highway 25E, north of Thorn Hill, Avondale (T.V.A.
162-SW) Quadrangle; just above Sowerbyites zone, 4 mile east of Beech Grove
Church, 3 miles west-southwest of Thorn Hill, Avondale (T.V.A. 162-SW)
Quadrangle; Sally Cleveland Farm, $ mile southwest of Washburn, Dutch Val-
ley (T.V.A. 154-SE) Quadrangle; 90 to 120 feet above the “Mosheim”’ lime-
stone on U. S. Highway 25E, north of Hayes’ house, 1 mile north of Indian
Creek, Evans Ferry section, Howard Quarter (T.V.A. 162-NW) Quadrangle ;
upper Lincolnshire formation, # mile southwest of Mount Eager Church,
Hogskin Valley, Powder Springs (T.V.A. 154-SW) Quadrangle.

MACROCOELIA ELEGANTULA Cooper, new species
Plate 233, C, figures 7-12; plate 235, C, figures 5-16; plate 247, D, figures 11-13

Medium sized for the genus, attaining a width of about 14 inches; wider than
long with the hinge varying from shorter to wider than the midwidth; sides more
or less oblique; anterior margin strongly rounded; surface costellate, costellae
alternating in size, about 3 to the millimeter at the front margin.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity at the middle; anterior profile strongly domed; beak small; umbo nar-
rowly swollen to form a short, low fold; posterior third gently swollen, median
third strongly swollen to form the most convex part; anterior slope gently con-
vex, long and steep; lateral slopes steeper than the anterior one. Interarea short
and curved; pseudodeltidium small and short. Muscle field heart shaped, oc-
cupying the posterior third; median ridges strong.

894 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Brachial valve moderately and fairly evenly concave; deepest part at middle;
sides and anterior deflected moderately toward the brachial valve. Interior with
delicate cardinal process ; short median ridge and slender adductor ridges, all 5 of
the latter well developed.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
FHloloty pew. we spelen. 31.4 29.1 36.0 28.8 ? 6.4
Paratype (117776a).. 28.3 25.6 38.6 37.8 vee
oy (117772) 5 «0270 25.8 31.4 31.2 5 fee

Types.—Holotype: 117773; figured paratypes: 117772, 117774a,b, 117775,,
117776a,b; unfigured paratypes: 117775b-d, 117776c,d.

Horizon and locality—Whistle Creek formation in Virginia: Along U. S.
Highway 60 about 14 to 2 miles northwest of Lexington and on Whistle Creek
northwest of Lexington, Lexington (15’) Quadrangle.

Discussion.—This species is characterized by its small size for the genus, its
fairly strong convexity, and the even, gentle concavity of the brachial valve. The
species is not well known because it is quite rare. The specimens so far col-
lected indicate some variability in the species particularly in the hinge width. No
other described species of Macrocoelia is quite like this one. Macrocoelia rotunda
is generally squarer and more convex and has a more concave brachial valve.
Macrocoelia plebeia does not approach it in size or convexity.

MACROCOELIA MAGNA (Butts)
Plate 231, C, figures 9-14; plate 232, A, figures 1-7; plate 235, E, figures 17-21;
plate 236, C, figure 13; plate 230, C, figure 29
Rafinesquina magna Burts, Virginia Geol. Surv. Bull. 52, p. 85, pl. 86, figs. 1-4, 1942.

Shell large for the genus in adult form, moderately convex, wider than long
with the greatest width at the hinge in the young but near the middle in old
adults. Anterior margin broadly rounded; lateral margins generally oblique.
Surface marked by costellae of unequal size, the costellae at the posterior very
different in size, the larger ones separating I to 3 finer ones. Costellae on the
anterior part of the valves becoming more uniform in size, but 1 to 3 finer cos-
tellae may be seen between the coarser ones although this is not so frequent as
at the posterior of the valves. Finer costellae cancellated by strong fila. A few
oblique wrinkles occurring on each side of the beak along the posterior margin.

Pedicle valve moderately convex in lateral profile with the greatest convexity
located slightly anterior to the middle. Lateral slopes moderately steep ; postero-
lateral slopes to cardinal extremities gentle. Interarea short; approximately
orthocline. Foramen minute, pseudodeltidium short, not strongly arched.

Brachial valve moderately and fairly evenly concave; posterior two-thirds
gently concave but anterior third somewhat abruptly bent anteriorly. Cardinal
extremities very slightly deflected in an anterior direction. Interarea short;
chilidium short and low.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 895

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Figlotypen sisi be Ns ATO LY 60.0 56.7 78.6 84.0 ? 7.5-+
Hypotype (117777)......... 61.2 57.7 73.6 61.2 11.5
sf QuI77 Sia) eset 46.5 43.9 55.2 49.1 6.7

Types.—Holotype: 98199; figured hypotypes: 117778, 117779a, 117780a,
117781a,b,d; unfigured hypotype: 117777.

Horizon and locality—Benbolt formation in Tennessee: Along the road
1.6 miles northeast of Heiskell, Powell Station (T.V.A. 137-SE) Quadrangle ;
100 yards west of the store, junction of Tennessee Highway 33 and Flint Creek,
Maynardville (T.V.A. 145-SE) Quadrangle ; 14 miles northeast of Halls School,
Howard Quarter (T.V.A. 162-NW) Quadrangle; 4 mile southwest of Fleanor
Mill, Powell Station (T.V.A. 137-SE) Quadrangle; hillside south of Dutch,
Maynardville (30’) Quadrangle; 4 mile west of Dodson Creek on road from
Tennessee Highway 33 to Acuff, Maynardville (T.V.A. 145-SE) Quadrangle ;
west side of the sharp loop on the road down Flint Creek, Powder Springs
(T.V.A. 154-SW) Quadrangle.

Benbolt formation in Virginia: 100 to 150 yards north of the triangular in-
tersection at Rye Cove and elsewhere in the vicinity of Rye Cove, Clinchport
(T.V.A. 188-NW) Quadrangle; § mile south of Gate City, Gate City (T.V.A.
188-NE) Quadrangle; on Virginia Highway 74, 0.2 mile southwest of New
Bethel Church, Hilton (T.V.A. 197-NW) Quadrangle; Mount Hagan School,
Hilton (T.V.A. 197-NW) Quadrangle; 0.67 mile south of Tumbez, Moll Creek
(T.V.A. 196-SE) Quadrangle.

Discussion.—This species is best identified by its large size; it is the largest
known brachiopod occurring in the Southern Appalachians. As identified herein
the shell is variable and shows considerable range in its convexity and shape.
It is quite probable that more collecting will ultimately lead to the separation of
more species from it. The species can be recognized in small pieces by its ap-
parent flatness and the thin body cavity. In its complete form, however, the
species is strongly convex. A good deal of the variability is due to flattening by
compression. It will be noted that some of the specimens figured show fractures
from compression with a consequent flattening of the shell.

Macrocoelia magna is approached in size by M. duplistriata (Willard) of the
Lincolnshire, Hogskin member, but is much less concave in the brachial valve
and is more convex in the adult form than the stratigraphically lower species.

MACROCOELIA OBESA Cooper, new species
Plate 230, C, figures 14-19
Shell moderately large for the genus, semielliptical in outline; wider than
long with the greatest width slightly anterior to the hinge. Strongly concavo-

convex in lateral profile. Lateral margin gently rounded; anterior margin
broadly rounded. Surface multicostellate, with 2 to 6 costellae separating the

896 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

larger ones. Costellae cancellated by fila. At the front margin of an adult 5
of the larger costellae occupy a space of 5 mm.

Pedicle valve with posterior slope moderately steep in lateral profile. Median
region gently convex and anterior slope moderately steep but less so than the
posterior slope. Umbonal and median region inflated ; lateral slopes steep. Slopes
to cardinal extremities fairly gentle and slightly concave. Interarea short, nearly
orthocline ; pseudodeltidium small.

Brachial valve with concave umbonal region, lateral and median third of shell
gently concave ; anterior and lateral marginal regions geniculated gently toward
the brachial valve, thus accentuating the depth of concavity of the valve. Inter-
area short, chilidium short and narrowly arched.

Pedicle interior with short, widely divergent but well-defined ridges that ex-
tend anterolaterally for a short distance around the posterolateral parts of the
muscle area. Teeth unusually small for such a large shell. Muscle field large and
flabellate. Median ridge not developed.

Interior of brachial valve with the lobes of the cardinal process having short
shafts but the myophore surface moderately broad and lobate on the edge toward
the pedicle valve. Callus deposit about the delicate brachiophores very slight.
Median ridge low; accessory ridges moderately well developed.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Foelatype tresa nd. + 2niisieaeuele 35.0 32.7 40.8 ? 30.2 6.8
Paratype (117783b)....+..... 227 P 39.3 39.0 ? r

Types.—Holotype: 117783a; figured paratypes: 117782a,b; unfigured para-
types: 117782c, 117783b,c.

Horizon and locality—Arline formation in Tennessee: At 4 mile south of
McMullens, Meadow (T.V.A. 139-NW) Quadrangle; 4 mile southeast of
Friendsville, Concord (T.V.A. 138-SW) Quadrangle; 54 miles southeast of
Knoxville; 1 mile southeast of Fowlers Mill which is 10 miles south of Loudon,
Loudon (30’) Quadrangle; 1 mile east-northeast of Friendsville, Louisville
(T.V.A. 138-SE) Quadrangle.

Discussion——Macrocoelia obesa is of moderate size for the genus, is strongly
convex and fairly deeply concave. In these respects it resembles M. bella (for
comparison see that species), M. champlainensis, and M. rotunda. The Tennes-
see species differs from M. champlainensis in having more delicate ornamenta-
tion, a more concave brachial valve, and a narrower hinge. Macrocoelia obesa
differs from M. rotunda in its narrower hinge, much less convexity, and finer
ornamentation.

MACROCOELIA OCCIDENTALIS Cooper, new species
Plate 233, D, figures 13-20
Large, attaining a width of nearly 2 inches; hinge variable from wider than

the midwidth to equal the midwidth ; cardinal extremities alate; sides subparallel
to gently oblique; anterior margin broadly rounded; costellae strongly differ-

PART CHAZYAN AND RELATED BRACHIOPODS—COOPER 897

entiated, the larger ones setting off groups of several smaller ones, all beautifully
cancellated by strong fila; prominent oblique wrinkles marking posterior margins.

Pedicle valve fairly evenly and moderately convex in lateral profile and with
the maximum convexity at the middle; anterior profile fairly evenly and broadly
convex ; umbonal region gently swollen ; median region swollen and full; anterior
slope steeper than the lateral slopes because of a fairly abrupt bending of the
anterior third toward the brachial valve. Pseudodeltidium a remnant.

Brachial valve flat to gently convex in the posteromedian region ; anterior third
gently deflected toward the pedicle valve.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
TIpigtupe acces yacls siete sae, « 37.9 36.9 45.2 48.4 5.0
Pararype, ClI77O4 sce sss suse 35.9 ? 44.4 ? cy
2 RITZ ZO5O parece cess 29.0 P 34.3 42.6 ?

Types.—Holotype: 117787; figured paratypes: 117784, 117785c; unfigured
paratypes: 117785a,b,

Horizon and locality.—Yellow-weathering limestone in Roberts Mountains
(1°) Quadrangle, Nev.: Above 25-foot sandstone at base of Eureka group on
the crest of the Antelope Range, 3 miles south of Nine Mile Canyon; in the
saddle just north of hill 8167, Martins Ridge, Monitor Range; 2 and 3 miles
north of Martin Ranch; 1.9 miles N. 31° E. of Blair (=Segura) Ranch.

Discussion.—This species is distinguished by its moderately large size, wide
hinge, flattish brachial valve, and generally low or moderate convexity. It is
suggestive of M. duplistriata but does not attain the large size or fairly strong
convexity of that species. In size it is similar to M. bella, but it is less convex
and with a flatter brachial valve.

MACROCOELIA ORNATA Cooper, new species
Plate 233, A, figures 1-3; plate 236, A, figures 1-7

Shell of moderate size for the genus, attaining a width of nearly 14 inches;
hinge forming the widest part ; cardinal extremities alate; sides gently rounded,
oblique; anterior margin broadly rounded; surface marked by costellae formed
into groups of as many as 8 fine ones bounded by stronger costellae.

Pedicle valve moderately convex in lateral profile and with the maximum
convexity slightly anterior to the middle; anterior profile moderately domed;
umbonal region gently swollen ; median region moderately swollen; lateral slopes
long and moderately gentle; anterior slope short and steep; interarea moder-
ately long; pseudodeltidium small. Interior with long, slender median ridge;
diductors with prominent thickenings along their inner edge.

Brachial valve with posterior flat to gently concave in lateral profile; maxi-
mum concavity anterior to the middle; sides and anterior margins deflected
gently in the direction of the brachial valve; cardinal extremities deflected
slightly toward the pedicle valve and forming a small concavity.

898 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—Holotype, length 27.5, brachial length 25.2, midwidth
36.4, hinge width 41.2 +, thickness 6.4.

Types.—Holotype: 117789c; figured paratypes: 117788a, 117789a; unfigured
paratypes: 117788b-d, 117789b.

Horizon and locality—Little Oak formation in Alabama: At the junction of
Bailey Gap and Cahaba Valley roads, SWiSW3 sec. 13, T. 19 S., R. 2 W.,
13 miles northeast of Newhope Church, Vandiver (15’) Quadrangle.

Discussion—tThis species has strongly marked ornamentation, the larger cos-
tellae standing out prominently in a mat of finer ones. The species has moderate
size and moderate convexity. It is larger and more strongly ornamented than
M. elegantula. It is wider and less convex than M. obesa and is smaller and
more elegantly ornamented than O. occidentalis. Another feature of this species
not seen on any other member of the genus is the flattening or even slight con-
vexity of the posterior third of the brachial valve. This feature is pronounced
on the holotype.

MACROCOELIA PLATYS Cooper, new species
Plate 231, A, figures 1-7

Shell of about medium size for the genus, wider than long; hinge equal to or
narrower than the midwidth; sides gently convex, slightly oblique; anterior
margin strongly rounded ; costellae alternating strong and fine, 3 or less of the
latter alternating with the stronger ones; 3 costellae to the millimeter at the
front margin.

Pedicle valve moderately convex in lateral profile and with the maximum
convexity at the middle; anterior profile broadly and moderately domed; umbo
narrowly swollen and forming a low fold that extends anteriorly nearly to the
middle; median region moderately swollen; anterior slope long and gentle; lat-
eral slopes shorter and steeper than the anterior one. Pseudodeltidium short;
interarea moderately long. Muscle field heart shaped, moderately large.

Brachial valve nearly flat to gently concave in lateral profile; most concave in
the median region but becoming shallow to flat toward the margins.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype seus sessieet a Ball! 32.8 30.8 38.4 34.3 6.0
Paratype ot UUZ7GOd) MFA escuree4 32:2 ? 37.6 30.9 ?

Types.—Holotype: 117790a; figured paratypes: 117790b,c; unfigured para-
types: 117790d-l.

Horizon and locality—Lincolnshire formation in Tennessee: At Marble Bluff,
8 miles west-northwest of Loudon, Loudon (30’) Quadrangle.

Discussion.—This species is characterized by moderate size and low convexity
and an almost flat brachial valve. In these respects it is like M. occidentalis, but it
is smaller and flatter than that species. It is very similar to the young of
M. duplistriata, and more extensive collecting may ultimately prove them to be
the same.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 899

MACROCOELIA PLEBEIA Cooper, new species
Plate 121, G, figures 18, 19; plate 233, B, figures 4-6

Shell small for the genus, wider than long and with the hinge slightly wider
than the midwidth ; cardinal extremities auriculate. Sides slightly oblique; an-
terior margin somewhat narrowly rounded. Surface marked by fine costellae
set off into groups by stronger costellae, 2 of the stronger costellae occurring in
I mm. and generally setting off groups of 3 or 4 of the finer costellae.

Pedicle valve fairly strongly convex in lateral profile and with the maximum
convexity at about the middle; anterior profile moderately convex and with the
median region narrowly humped and with long lateral slopes. Umbo narrowly
convex, the convexity continuing to the swollen median region where it is dissi-
pated in the swelling; lateral slopes long, moderately steep; posterolateral ex-
tremities flattened.

Brachial valve gently concave and with the maximum concavity at about the
middle ; sides and anterior margins somewhat flattened.

Brachial interior with short and low median ridge, small and narrow cardinal
process lobes and adductor ridges faintly developed.

Measurements in mm.—

Brachial Hinge Thick-
Length length width Midwidth ness Height

Halaty pe oFss ssvles Se 12.7 12.0 14.9 14.6-+- ? ?
Paratype (117791)... 15.8 ? 18.0 18.3 ? 3.6

Types.—Holotype: 117793a; figured paratypes: 117791, 117793b.

Horizon and locality—Lenoir formation (Mimella-Valcourea zone) in Ten-
nessee: In a small quarry between the Southern RR. tracks and U. S. High-
way II, 14 miles southwest of Philadelphia, Philadelphia (T.V.A. 131-NW)
Quadrangle; 0.9 mile west-northwest of Ellejoy Church, Wildwood (T.V.A.
147-SE) Quadrangle; 45 feet above the base of the Lenoir, 0.1 mile southwest
of triangulation mark 37SH, Wildwood (T.V.A. 147-SE) Quadrangle.

Discussion.—This is a small species of moderate convexity. It is smaller and
more quadrate than M. elegantula and is quite unlike any of the other species.
It suggests Opikina, but the brachial valve is not geniculated.

MACROCOELIA ROTUNDA Cooper, new species
Plate 234, A, figures 1-5

Rafinesquina cf. R. champlainensis Butts (not Raymond), Virginia Geol. Surv. Bull. 52,
Dp. 85, pl. 86, figs. 5-7, 1942.

Shell large for the genus, attaining a length of more than 2 inches; slightly
wider than long; sides gently rounded; subparallel; hinge shorter or wider than
the midwidth; cardinal extremities slightly auriculate. Anterior margin nar-
rowly rounded. Costellae moderately strong, well differentiated into coarse and
fine.

Pedicle valve strongly convex in lateral profile and with the maximum con-
vexity slightly anterior to the middle; anterior profile strongly domed, with

goo SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

steep sides; beak small, umbo swollen; median region strongly inflated ; anterior
slope steep. Interarea moderately long and curved. Pseudodeltidium nearly
obsolete.

Brachial valve most deeply concave in the median region. Sides and anterior
sloping steeply toward the middle; cardinal extremities deflected toward the
pedicle valve.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype) yrratewlatnvatxaws - 35.5 33.0 38.4 32.2 8.0?
Paratype (98200b).......... 50.3 46.2 51.4 41.0 11.4
a (OR2006 5s aig ass Se 36.9 33.8 40.2 40.6 ?
7 (ATZFOAD ) are sini" 65.6 60.0 72.6 71.0 16.4

Types.—Holotype: 98200a; figured paratype: 98200c; unfigured paratypes:
98200b, 117794a,b.

Horizon and locality—Benbolt formation in Virginia: At Green Valley
Church, 3 miles southeast of Lebanon, Brumley (T.V.A. 205-SE) Quadrangle;
several localities in the vicinity of Rye Cove, Clinchport (T.V.A. 188-NW)
Quadrangle.

Discussion.—This is another gigantic form as large as M. magna, but it is
represented in the collections by only a few specimens. Consequently, all the
details for this species cannot be listed at the present time. It is characterized
by strong convexity and has a deeply concave brachial valve. The cardinal ex-
tremities are marked by small ears. The square outline and rotundity are charac-
teristic. No other described species is so strongly rotund. It differs from
M. magna in its greater depth, thicker body region, and squarer outline. A speci-
men sectioned through the middle shows a thick marginal rim on the anterior
margin of the brachial valve. This anterior marginal brim is one of the prime
distinctions between Macrocoelia and Opikina, the latter being thickened at the
place of geniculation and having a thin trail anterior to the rim.

MACROCOELIA RUEDEMANNI (Salmon)

Rafinesquina alternata RUEDEMANN (not Emmons), New York State Mus. Bull. 40, p. 16,
pl. 2, fig. I, 1901.

Opikina ruedemanni SALMON, Journ. Paleont., vol. 16, No. 5, p. 597, pl. 87, figs. 31-33, 1942.
Types——Holotype: Columbia Univ. 25909; paratype: Columbia Univ. 25916.
Horizon and locality.—Rysedorf conglomerate in New York: At Rysedorf

Hill, near Albany.

MACROCOELIA sp. 1

This is a moderate-sized species, slightly wider than long as usual in the genus.
Hinge wider than the midwidth and cardinal extremities pointed. Only pedicle
valves are so far known ; consequently, no effort is made to describe the species.
The lateral profile is moderately convex with the maximum convexity slightly
anterior to the middle. The anterior profile is strongly domed. The umbo is
swollen broadly but is not continued anteriorly as a fold. Lateral slopes and

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER gol

anterior slope are steep. The costellae are differentiated on the posterior and
median parts but are more nearly equal in size at the anterior.

Measurements in mm.—117796a, length 27.5, midwidth 28.2, hinge width 33.3,
height 7.7.

Described specimens.—117796a,b.

Horizon and locality—Lenoir formation in Tennessee: 2 miles southeast of
Whitesburg, Bulls Gap (T.V.A. 171-SE) Quadrangle.

PIONOMENA Cooper, new genus

(Greek pion, fat; mene, crescent)

Shells generally small, attaining a length of about 3 inch; compressed bicon-
vex; hinge straight, generally not equal to the maximum width which is near
the middle. Anterior commissure rectimarginate to gently sulcate ; surface multi-
costellate, costellae varying in size, usually somewhat fasciculate.

Pedicle interior with moderately large teeth and long, flat dental ridges ; muscle
area suboval to cordate; posteriorly surrounded by the sides of the delthyrial
cavity and 2 long, thin, curving plates laid against the inner side of the dental
ridge. Pseudodeltidium narrowly convex ; foramen small.

Brachial valve with well-developed chilidium ; cardinal process bilobed, small
and delicate. Sockets formed by short, wide cups formed by a thin and delicate
plate.

Genotype-—Pionomena neumani Cooper, new species.

Discussion.—This genus is characterized by its biconvex profiles, the fascicu-
late ornamentation, and the presence of strong dental ridges in the pedicle valve,
which simulate thin dental plates. The genus differs from Strophomena and
Rhipidomena in its biconvex profiles, strongly fasciculate ornamentation, and
the development of thin, curving ridges laid against the inside surface of the
teeth.

PIONOMENA ? DUBIA Cooper, new species
Plate 246, E, figure 15

Undetermined genus related to Rafinesquina? Burts, Virginia Geol. Surv. Bull. 52, p. 67,
pl. 80, figs. 1-3, 1942.

Shells attaining a width of slightly less than an inch; subrectangular in out-
line, biconvex in profile ; hinge slightly less than the midwidth ; cardinal extremi-
ties obtuse; anterior margin broadly rounded; surface multicostellate, costellae
alternating, I or more fine costellae with stronger ones between, about 4 to the
millimeter at the front margin, all strongly cancellated by strong concentric fila.

Pedicle valve with lateral profile gently convex and the maximum convexity
at about the middle; anterior profile broadly convex and with the median region
subcarinated. Umbo narrowly convex, the convexity continued anteriorly at
least to the middle as a low, broadening fold; umbonal slopes long and gentle;
median region swollen; anterior slope long and gentle. Apex perforate.

Brachial valve gently convex in lateral profile and with the maximum con-

go2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 127

vexity at the middle; anterior profile broad and gently convex ; umbo marked by
a narrow and shallow sulcus; median region moderately swollen; lateral and
anterior slopes short but gentle. Cardinal process bilobed as usual in the genus.

Measurements in mm.—
Brachial Hinge Thick-

Length length Midwidth width ness Height
Plolotype sb. Psd." 12.6 ? Te 16.0 ? 28
Paratype (123277a).. 15.0 ? 21.3 19.4 ? Bune
“a Ciag977 bina FP 13.4 19.5 17.4 ? 1.9

Types.—Holotype: 98222; unfigured paratypes: 123277a,b.

Horizon and locality—FEffna formation in Virginia: At Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This species differs from the others described herein in the char-
acter of the ornamentation. It is wider and somewhat larger than P. newmam
and has much finer ornamentation. Indications are that this species is definitely
a strophomenoid with fairly strongly convex valves and with the cancellated
ornament characteristic of young strophomenoids.

PIONOMENA NEUMANI Cooper, new species
Plate 265, D, figures 7-11

Shell attaining a length of about 0.6 inch; subcircular to subquadrate in out-
line, with the greatest width at about the middle; hinge narrower than the great-
est shell width; sides nearly straight to gently rounded; anterior margin strongly
rounded ; costellae of unequal size, about 21 in 5 mm. at the front margin, the
stronger ones separated by 1 to 5 of the finer costellae.

Pedicle valve very gently convex in lateral and anterior profiles; umbonal
region marked by a narrow fold that extends anteriorly to beyond the middle
where it disappears in the general convexity; flanks of fold gently concave and
extending by long, gentle slopes to the margins. Anterior slope nearly flat.

Brachial valve gently convex in anterior and lateral profiles ; umbo marked by
a shallow and narrow sulcus that widens anteriorly and reaches nearly to the
front margin. Flanks bounding sulcus gently swollen; posterolateral slopes to
flattened cardinal extremities short and moderately steep.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (pedicle valve).......... 14.1 ? 15.7 13.9 ?
Paratype ( “ MT Te7SOD) oa aed ? 15.6 13.9 ?
(brachial valve 117756c). ? 12.0 14.6 12.9 ?

Types.—Holotype: 117756a; figured paratypes: 117755, 117756b-d.

Horizon and locality—New Market formation (in the top 12 feet) in Wil-
liamsport (15’) Quadrangle, Maryland: 4 mile southwest of Hicksville; 3 miles
N. 10° E. of Wilson; 3 mile north of St. Pauls Church, west of Wilson.

Same formation in Pennsylvania: 1 mile west-southwest of Marion, Cham-
bersburg (15’) Quadrangle. |

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 903

Same formation in Virginia: On Hiatt Run, 3 miles north of Winchester,
Winchester (15’) Quadrangle.

Elway formation in Giles County, Virginia: On Sinking Creek, 12 miles
northwest of Blacksburg.

Same formation in Tennessee: On U. S. Highway 25W, 4.7 miles south of
Clinton, Powell Station (T.V.A. 137-SE) Quadrangle.

Lincolnshire formation in Virginia: On the Norfolk and Western RR. 4 mile
upstream from Benton Station, Giles County.

Discussion.—This species is more strongly costellate than P. ? dubia. The
pedicle valve is marked medianly by a narrowly folded umbo and the brachial
valve has a corresponding sulcus, both features being better developed than on
corresponding parts of the Effna species. It is larger and more finely fasciculate
than P. pulchra from the Grazier limestone of Pennsylvania.

PIONOMENA PULCHRA Cooper, new species
Plate 248, C, figures 4-7

Shell small, unequally biconvex, the pedicle valve having the greater con-
vexity. Hinge narrower than the greatest width which is at about the middle.
Sides and anterior margin well rounded. Surface fascicostellate.

Pedicle valve somewhat carinate umbonally but with flattened to somewhat
concave lateral areas. Umbo continued anteriorly as a low fold which does not
meet the anterior margin. Brachial valve gently convex and marked medially
by a shallow sulcus best defined in the posterior third but variable.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (brachial valve) ........ i 10.2 13.3 10.5 Fy
Paratype (pedicle valve 123275c).. 10.8 ? 11.6 10.0 ?

Types.—Holotype: 123275b; figured paratype: 123275c; unfigured paratype:
1232758.

Horizon and locality—Carlim formation (base) =Grazier member of the Hat-
ter formation, in Pennsylvania: On Elk Run, 3 miles southwest of Nealmont,
Tyrone (15’) Quadrangle.

Discussion—This species is suggestive of P. neumani but is smaller, has a
flatter brachial valve and more distantly fasciculate ornamentation.

Genus 6PIKINA Salmon, 1942
Opikina SALmon, Journ. Paleont., vol. 16, No. 5, p. 589, 1942.

OPIKINA ALATA Cooper, new species
Plate 246, C, figures 5-11
Shell small for the genus, wider than long; hinge forming the widest part;

cardinal extremities alate; sides oblique; anterior margin narrowly rounded;
costellae numbering 5 or 6 at the front margin.

904 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve with moderately convex visceral region, rounded geniculation,
and steep, moderately long trail. Angle of geniculation about 96° ; geniculation
occurring 5 to 6 mm. anterior to the beak; sides steep; umbo narrowly convex ;
interarea short.

Brachial valve with gently concave visceral region; deepest anterior to the
middle just below the steep trail; sides moderately deflected toward the brachial
valve; anterior margin strongly deflected; internal septa mostly covered by
adventitious shell.

Measurements in mm.—Holotype, length 10.5, brachial length 9.3, midwidth
13.6, hinge width 16.4, thickness 2.0?, height 4.8, trail length 7.0.

Types.—Holotype: 117797c; figured paratype: 117797b; unfigured paratype:
1177972.

Horizon and locality—Edinburg formation (Nidulites zone) in Strasburg
(15’) Quadrangle, Virginia: 100 yards south of the entrance to Battlefield
Crystal Caverns on U. S. Highway 11, 1 mile north of Strasburg; along
Tumbling Run, 14 miles southwest of Strasburg.

Discussion—This species is characterized by the ears on the cardinal ex-
tremities, small size, and geniculation near the middle. The species may be con-
fused with O. dorsatiformis and O. parvula which has about the same size. It
differs from the former in being much less convex and in not geniculating at so
early a stage of growth as O. dorsatiformis. It differs from O. parvula in having
its place of geniculation at the middle rather than anterior to the middle and
in having more pronounced ears.

OPIKINA BELLULA Cooper, new species
Plate 242, D, figures 14-25

Small for the genus, subrectangular, wider than long with the hinge forming
the widest part; cardinal extremities subauriculate ; sides gently rounded, gently
oblique; anterior margin narrowly rounded; surface strongly costellate, costellae
on visceral area with strong costellae separated by numerous fine ones but trail
marked by strong costellae with the finer ones distinctly subordinate; 2 or 3 of
the stronger costellae in 1 mm. at the front margin. Strong wrinkles on posterior
margins.

Pedicle valve unevenly convex in lateral profile, the visceral region being
nearly flat to gently convex but the front third strongly angulated about 10 mm.
anterior to the beak; angle of geniculation about 110°; umbo narrowly swollen,
the swelling continued anteriorly as a low fold. Visceral disk region gently
swollen ; anterior and lateral slopes short and steep.

Brachial valve with visceral region concave and with lateral and anterior mar-
gins fairly strongly deflected toward the brachial valve.

Measurements in mm.—

Brachial Hinge Thick- Trail
Length length Midwidth width ness Height length
EDOIGtHOS ME ees ices Ce oes 15.3 ? 17.8 19.2 ? SO" 8 Fee

Paratype (117799b).... 14.9 13.7 18.0 19.0 ? 5.0 7.5

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 905

Types.—Holotype: 117799a; figured paratypes: 117799b-e.

Horizon and locality Edinburg formation (Cyrtonotella zone) in Strasburg
(15’) Quadrangle, Virginia: In the ravine at the switch about 4 mile east of
Strasburg Junction; Tumbling Run, 14 miles southwest of Strasburg.

Shippensburg formation (Echinosphaerites zone) in Maryland: On the west
bank of Conococheague Creek on U. S. Highway 40, 7 miles west of Hagers-
town, Williamsport (15’) Quadrangle.

Discussion—This species is characterized by its moderate size, low convexity,
and fairly strong costellae. The general form of the shell is suggestive of
O. speciosa and O. formosa, but these are larger and more strongly geniculated
species. It is more convex and more strongly ornamented than O. minnesoten-
sis. Opikina varia from Alabama is somewhat similar in size and form but is
more strongly geniculated and the interior of the brachial valve has the septa
more strongly developed.

OPIKINA CLARA (Okulitch)

Rafinesquina clara Oxu.ircu, Canadian Field-Nat., vol. 49, No. 6, p. 97, pl. 1, fig. 1, 1935.
Opikina clara (Okulitch) Satmon, Journ. Paleont., vol. 16, No. 5, p. 597, pl. 87, fig. 28, 1942.

Type.—Holotype: Peter Redpath Mus.
Horizon and locality —Leray =Chaumont in Quebec: At Pointe Claire.

OPIKINA DORSATIFORMIS Cooper, new species
Plate 237, B, figures 20-28; plate 242, B, figures 6-10

Small for genus, subquadrate; length and width about equal; sides gently
rounded, subparallel; anterior margin narrowly rounded; hinge narrower than
the midwidth ; cardinal extremities rounded. From 3 to 5 costellae in I mm. at
the front margin; short wrinkles appear on the posterior margin.

Lateral profile strongly convex; visceral region not strongly differentiated
from the trail; geniculation occurring about 5 mm. anterior to the beak; visceral
region gently convex and provided with obscure concentric wrinkles; angle of
geniculation less than a right angle; trail long and moderately convex; lateral
slopes precipitous.

Brachial valve deeply concave and deepest at the middle; umbo sulcate, the
sulcus extending for a short distance anteriorly; sides and anterior margin
strongly deflected toward the brachial valve and forming a high rim around the
median concavity.

Measurements in mm.—

Brachial Hinge Thick- Trail

Length length Midwidth width ness Height length

olotypeis sats. raetses 13.6 11.6 14.2 muy, 3.9 7.4 17.5
Paratype (117800)... 10.4 2 12.4 11.9 iy 4.7 10.0

Types.—Holotype: 117801 ; figured paratype: 117800.
Horizon and locality—Edinburg formation (Cyrtonotella and Nidulites
zones) in Strasburg (15’) Quadrangle, Virginia: Just east of a small ravine on

906 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the north side of the road along Tumbling Run, 14 miles southwest of Strasburg ;
in the ravine at the switch about 4 mile east of Strasburg Junction.

Discussion.—This species is recognized by its small size and nearly hemispheri-
cal lateral profile. It is most like O. dorsata from the Kuckers formation of
Estonia but differs in having squarer outline and wider hinge than the Estonian
species. Furthermore, the Estonian species is somewhat more convex and
smaller.

OPIKINA ? DUBIA Cooper, new species
Plate 246, D, figures 12-14

Shell small, length and width about equal; sides nearly parallel ; hinge slightly
wider than or equal to the midwidth; anterior margin narrowly rounded; sur-
face costellate, 4 or 5 costellae in 1 mm. at the front margin.

Pedicle valve with lateral profile uneven, the umbonal region slightly convex,
the area just anterior to the middle slightly concave, and the marginal regions
abruptly bent in the direction of the brachial valve; anterior profile broadly and
slightly convex. Umbonal region gently convex; region just posterior to the
margin gently concave; margins bent toward the brachial valve narrowly and
abruptly ; lateral and anterior slopes short and precipitous.

Brachial valve with concave umbo but gently convex visceral region ; margins
bent abruptly toward the brachial valve; postmarginal areas narrowly concave.

Measurements in mm.—

Brachial Hinge Thick-
Length length Midwidth width ness Height
Holotype (pedicle valve).. 14.4 ? 16.2 16.0 ? 2.5
Paratype (brachial valve). ? 13.4 14.6 14.9 ? ?

Types.—Holotype: 123274a; figured paratype: 1232738.

Horizon and locality—Botetourt formation in Virginia: In Lexington (15’)
Quadrangle, 1 mile northwest of Lexington; 2 miles south of Stag Back Moun-
tain, 7 miles north-northeast of Lexington. Near Cedar Grove Church and
School, 14 miles southeast of Harrisonburg, Harrisonburg (15’) Quadrangle.

Discussion.—The almost flat to gently concave lateral profile and strong mar-
ginal geniculation of this species separate if from all other known species of the
genus except O. nasuta (which see). No interiors of this are known. The
generic assignment is therefore questioned because of its peculiar form.

OPIKINA EXIMIA Cooper, new species
Plate 240, B, figures 8-18

One of the largest of known species; subquadrate, length and width nearly
equal; sides gently curved, subparallel; hinge forming the widest part; cardinal
extremities auriculate; anterior margin narrowly rounded. Costellae well dif-
ferentiated, 2 of the stronger ones in I mm. at the front margin. Strong wrinkles
on posterior margins.

Pedicle valve of uneven convexity in lateral profile, the posterior two-thirds
gently convex and the anterior third fairly strongly geniculated ; anterior profile

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 907

strongly domed; angle of geniculation varying from 100° to 120°, and formed
about 20 mm. anterior to the beak. Umbo broadly and gently swollen; beak
inconspicuous ; visceral region gently inflated ; lateral slopes long and steep; an-
terior slope long and steep. Muscle field large, occupying nearly half the interior.
Pseudodeltidium small and having a median depression.

Brachial valve deeply concave just anterior to the middle; visceral region
gently concave ; posterolateral extremities flattened at the ears; sides and anterior
margin strongly deflected toward the brachial valve; umbo broadly but gently
concave. Interior with septa mostly buried by adventitious shell substance; the
2 outside septa short and thick; cardinal process large and thick; subperipheral
rim thick.

Measurements in mm.—

Length
Brachial Hinge Thick- of
Length length Midwidth width ness Height trail
Frolotype’ 2’... 22%, 24.6 23.0 28.8 31.6 3.8 7.5 8.0
Paratype (117806b)... 23.3 21.7 25.2 26.3 ? 9.5 II.0
a (117803).... 29.0 26.5 32.0 35.9 6.3 12.1 ?

Types.—Holotype: 117806a; figured paratypes: 117802, 117803, 117804a,
117805, 117806b; unfigured paratypes: 117804b, 117806c,d.

Horizon and locality Lebanon formation in Tennessee: From the Doleroides
zone on U. S. Highway 70N opposite Fairview Service Station, 4 mile west of
Rome; east end of the bridge on U. S. Highway 70N over Round Lick Creek,
Rome, Smith County. Columbia, Maury County. On U. S. Highway 41, 3 mile
south of Knox Branch, 9 miles southeast of Murfreesboro; 3 miles east of Mur-
freesboro ; U. S. Highway 241, 14 miles (airline) southwest of Christiana, Ruth-
erford County. Lebanon, Wilson County.

Camp Nelson formation in Kentucky: At High Bridge, Harrodsburg (30’)
Quadrangle.

Discussion.—This is a large form that approaches some species of Macrocoelia
in size, but strong geniculation and characteristic rim in the brachial valve indi-
cate its affinity to Opikina. The species is smaller and more concave than
O. maja, the largest known species of Opikina. It is more convex than, but
almost as large as O. planulata.

The pseudodeltidium of this species is of interest because it is concave and
has a depressed line running along its length from its apex to the base.

OPIKINA EXPATIATA Cooper, new species
Plate 241, A, figures 1-8

Shell large, wider than long, subquadrate to subrectangular ; hinge variable,
ranging from wider to less than the midwidth; sides gently rounded, subparallel.
Costellae variable, differentiated into strong and fine; several strong costellae
may separate stronger ones on the posterior parts, but at the front margin the
costellae may be crowded and poorly differentiated to alternating fine and strong
and the costellae somewhat distant; 3 or 4 costellae occupying I mm. at the
front margin.

908 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve moderately convex in lateral profile, the maximum convexity
located anterior to the middle; anterior profile broadly domed ; valves not genicu-
lated but curved just anterior to the middle, the angle of the curvature being
about 130°. Beak small, umbo marked by a poorly defined narrow, low fold;
posterior half gently swollen; anterior half strongly swollen and with a long
steep anterior slope; lateral slopes long and steep. Interarea moderately long;
pseudodeltidium of many specimens marked by groove. Interior not known.

Brachial valve gently concave, most concave at about the middle; sides and
anterior margin moderately to strongly deflected toward the brachial valve. Pos-
terolateral region moderately flattened. Interior with unusually low septa and
ridges; brachiophores small and bladelike and with only a modest development
of the socket cups; subperipheral rim strong in old shells.

Measurements in mm.—
Brachial Hinge

Length length Midwidth width Thickness Height
Brolotyperii es isso. 28a ode 23.4 22.3 30.2 29.1 3.8 7.5
Paratype (117807b)..... 19.0 17.5 20.8 23.6 2.8 4.6
rh (117807d)).52... 19.2 18.1 22.3 227 3.0 6.0
s (117807e)..... 19.9 17a 23.4 27.1 2.5 5.0
a (r178075)) Ash 23.0 21.4 26.8 28.9 ? 6.1

Types.—Holotype: 117807a; figured paratypes: 117807b,c; unfigured para-
types: 117807d-f.

Horizon and locality. Bromide formation (Mountain Lake member) in Mur-
ray County, Oklahoma: On the east side of the road cut on Oklahoma High-
way 18, NW sec. 11, T.1 S., R. 3 E., 1.8 miles south of Sulphur ; Spring Creek,
ig ts ey pa Wd pres ete 5 a ib fs

Discussion.—This species is characterized by its fairly large size, moderate
but uneven convexity, width greater than the length, and the broad, open con-
cavity of the brachial valve. This species differs from O. formosa in its greater
size, more openly concave brachial valve, more subdued character of the septa
of the brachial interior, and less pronounced ears. It is similar in size and form
to O. lirata from the Decorah (Ion) of Minnesota but is more convex anteriorly,
has a longer interarea, and is less deeply concave. Some specimens suggest
O. speciosa, but that species is generally less wide, more strongly geniculated,
and more convex anteriorly.

OPIKINA EXTENSA Cooper, new species
Plate 243, A, figures 1-8

Shell moderately large for the genus, wider than long and with extended and
alate hinge; cardinal extremities acute; sides strongly oblique; anterior margin
broadly rounded; costellae of pedicle valve stronger and more even than those
of the brachial valve and numbering 3 to the millimeter; costellae of brachial
valve strongly differentiated into fine and strong, 2 of the latter in I mm. at the
margin and separated by 2 or 3 of the finer costellae. Posterior margins with
oblique wrinkles.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER go09

Pedicle valve moderately convex in lateral profile with the maximum convexity
in the anterior third ; posterior two-thirds gently convex ; anterior profile broadly
and gently convex; umbo narrowly swollen to form a short, low fold; median
region gently swollen; anterior third moderately swollen and bent toward the
brachial valve to form a short and steep anterior slope; lateral slopes long and
gentle.

Brachial valve gently concave, the maximum concavity at about the middle;
posterolateral regions flattened to form the ears; sides moderately, and anterior
margin fairly strongly, bent in the direction of the brachial valve.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Erolotype: sss eGo se Oe 19.8 18.4 29.5 40.6 4.7 6.9
Paratype (123268a)..... 19.8 18.7 27.0 ? 3.6 6.3

Types.—Holotype: 123268b ; figured paratype: 123268a ; unfigured paratype:
123268c.

Horizon and locality Bromide formation (Pooleville member) in Oklahoma:
3 miles northeast of Springer, Carter County.

Discussion.—This species is unlike any other described herein in the great
lateral extension of the hinge to form long, blunt ears. The species, by the simi-
larity of its ornamentation to that of O. formosa and expatiata, is undoubtedly
related to those species.

OPIKINA FORMOSA Cooper, new species

Plate 243, B, figures 9-17; plate 243, C, figures 18-28

Shell of about medium size for the genus, subquadrate, slightly wider than
long; hinge equal to or slightly less than the midwidth; cardinal extremities
nearly a right angle; sides subparallel; anterior margin somewhat narrowly
rounded. Costellae strong, alternating fine and strong on the posterior and not
strongly differentiated at the front margin where 4 costellae appear in the space
of I mm.

Pedicle valve unevenly to fairly evenly convex in lateral profile, the maximum
convexity just anterior to the middle; anterior profile strongly domed. Beak
prominent ; umbo narrowly swollen and forming a low, short fold; posterior half
gently to moderately swollen; angle of geniculation varying from 110° to 120°;
anterior slope or trail steep and nearly flat to gently convex in profile; sides
steep. Interior not known.

Brachial valve gently concave in the posterior half, more deeply concave an-
terior to the middle where the valve is deflected steeply toward the brachial
valve; umbo somewhat broadly concave; sides fairly strongly deflected in the
direction of the brachial valve. Interior with thickened and beaded subperipheral
rim; 5 septa well developed; cardinal process stout and long.

gio SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 127

Measurements in mm.—
Brachial Hinge

Length length Midwidth width Thickness Height
Holotype c:.cdS eh Wie 19.3 18.0 22.5 23.9 3.5 6.3
Paratype (123272c)..... 13.0 12.3 14.5 16.8 £7 2.9
“ (117800). «..,2%, 20.0 18.0 23.1 22.4 4.7 8.0
- (II7S10c).. «2. 19.1 17.7 21.9 20.8 3.9 6.3
CIV7OUIAD ons ss 18.9 17.3 22.8 20.9 3.9 6.2
43 (117811d)..... 15.0 14.2 17.6 17.2 2.5 3.8

Types.—Holotype: 123272a; figured paratypes: 117808, 123269b, 123270a,
123271a, 123272b; unfigured paratypes: 117809, 117810a-d, 117811a-d,e,f,
117813, 123272c-f.

Horizon and locality—Bromide formation (Pooleville member-O-roplecia
gouldi zone) in Oklahoma: At Rock Crossing, center sec. 35, T.5 S., R. 1 E.,
Criner Hills, 4 mile west of U. S. Highway 77, sec. 25, T. 2 S., R. 1 E.; West
Spring Creek, 3 miles east of Pooleville; NW4 sec. 26, T. 5 S., R. 1 E., Criner
Hills ; Carter County. Quarry on the east side of Oklahoma Highway 18, center
SW5 sec. 12, T. 1 S., R. 3 E., 2 miles south of Sulphur, Murray County; Spring
Creek, N4 sec. 17, T. 2 S., R. 1 W., Murray County.

Discussion.—This species is most like O. speciosa of all those described herein
but differs in being less convex, in having more pronounced ears, and in having
a shorter anterior trail.

OPIKINA GLABELLA Cooper, new species
Plate 230, A, figures 1-7; plate 247, C, figures 7-10

Medium sized for the genus, wider than long; subrectangular in outline and
with the hinge equal to or greater than the midwidth; sides gently rounded;
anterior margin broadly rounded; surface with well-differentiated costellae, 5 to
the millimeter at the front margin. Oblique wrinkles present on posterior margin.

Pedicle valve evenly and strongly convex in lateral profile, no marked posi-
tion of geniculation detectable; maximum convexity at or near the middle; an-
terior profile strongly domed; beak prominent; umbo narrowly swollen and
forming a small eminence anterior to the beak; median region strongly swollen ;
sides and anterior slope steep. Interarea short. Interior unknown.

Brachial valve fairly deeply concave, the greatest depth just anterior to the
middle ; posterior half gently concave but the umbo and median region marked
by a shallow sulcus. Sides moderately deflected but anterior margin strongly
deflected toward the brachial valve.

Measurements in mm.—Holotype, length 15.9, brachial length 15.0, midwidth
17.7?, hinge width 16.9?, thickness 3.9, height 6.5.

Types.—Holotype: 123267b; figured paratype: 123267a; unfigured paratype:
123267¢c.

Horizon and locality—Arline formation (upper) in Tennessee: On north
side of old road in glade, 4 mile southeast of Friendsville, Concord (T.V.A.
138-SW) Quadrangle.

Discussion—This species is characterized by having its length and width

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER OII

nearly equal, strong convexity with the maximum curvature at about the middle
and corresponding deep concavity. This species differs from O. matutina, another
species from about the same horizon, in being larger, squarer, and deeper. It is
larger and not so convex as O. dorsatiformis but is smaller and more convex
than O. bellula.

OPIKINA GREGARIA Cooper, new species
Plate 238, B, figures 8-18

Of about medium size for the genus, wider than long; hinge wider than or
less than the midwidth; cardinal extremities varying from a slightly obtuse
angle to acute and auriculate ; sides subparallel to oblique ; anterior margin some-
what narrowly to broadly rounded; ornamentation fine and subdued, variable,
that of the brachial valve somewhat finer than that of the pedicle valve, the cos-
tellae numbering about 4 to the millimeter. Posterior margins with oblique
wrinkles.

Pedicle valve unevenly convex in lateral profile, the maximum convexity lo-
cated just anterior to the middle; anterior profile broadly but moderately domed.
Posterior two-thirds gently convex; anterior third bent strongly but broadly
toward the brachial valve to form an angle of geniculation of 100° to 115°. An-
terior slope rounded, short and steep; lateral slopes longer than the anterior one
and less steep; broadly but gently swollen. Interarea short.

Brachial valve fairly strongly concave in the median and posterior regions,
most deeply concave just anterior to the middle; umbo concave; sides and an-
terior margin moderately curved toward the brachial valve. Interior with mod-
erate and beaded rim; cardinal process small; septa low and subdued.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Holotype. </o<./s » sistas Sara's 18.0 17.2 21.4 20.3 3.5 6.2
Paratype (117814a)..... 17.0 15.5 10.1 25.0 27 5.0
GEIZ STAG) eye ses 17.3 16.9 22.1 25.4 22 5.7
- (117814d)..... 13.9 13.2 16.4 16.0 1.9 By

Types.—Holotype: 117814b; figured paratypes: 117814a,c-e; unfigured para-
type: 117814f.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: On Oklahoma Highway 99, 3 miles south of Fittstown, Pontotoc County ;
just west of the road on Russell Ranch, SE} sec. 3, T. 2 S., R. 3 E., Murray
County.

Discussion.—This species is characterized by moderate size, moderate con-
vexity located anterior to the middle, fairly prominent ears, and unusually deli-
cate ornamentation. In the latter respect it differs from O. formosa and
O. expatiata, both Oklahoma species. It also differs from both of these in form
and degree of geniculation. It differs from O. septata in having a more rounded
geniculation and greater convexity. Opikina gregaria is shaped differently from
O. transversa, less strongly geniculated and generally with less prominent ears.

gi2 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

OPIKINA INQUASSA (Sardeson)
Plate 245, B, figures 9-12

Strophomena inquassa SARDESON, Minnesota Acad. Nat. Sci., Bull. 3, p. 334, pl. 5, figs. 22-24,
1802.

Opikina inquassa (Sardeson) SAtmon, Journ. Paleont., vol. 16, No. 5, p. 593, pl. 87,
figs. 12-14, 1942 (for complete synonymy).

Type.—Hypotype: 24206.
Horizon and locality—Decorah formation (Guttenburg member, Stictopora
bed) in Minnesota: At Minneapolis.

OPIKINA LIRATA Cooper, new species
Plate 247, F, figures 17-25

Shell large for the genus, subrectangular in outline, wider than long and with
a variable hinge; sides moderately rounded; anterior margin broadly rounded;
costellae differentiated as usual in the genus, 2 to 4 at the front in I mm., I to 3
of these usually of the finer grade. Valves often plaited by interruptions in growth
stages.

Pedicle valve fairly strongly convex in lateral profile and with the maximum
convexity located at the middle or slightly anterior to the middle; anterior pro-
file moderately to strongly and broadly domed. Not strongly geniculate, the
bending usually fairly broad and rounded; posterior gently convex; anterior
slope convex, long and steep; lateral slopes less steep than the anterior one.
Umbonal region somewhat swollen. Pseudodeltidium small, depressed inward.
Interarea short. Muscle field large, occupying about half the inner surface.

Brachial valve deeply concave in the median region; posterior region gently
concave; side moderately folded toward the brachial valve; anterior margin
strongly deflected toward the brachial valve. Interior with subdued septa, stout
cardinal process.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Holotype! +. i223 ean 23.2 21.7 30.0 24.5 3.6 7.0
Paratype (117816a)..... 24.2 22.8 32.0 29.0+ 3.8 7.8
4 (CTF7BT6b) 2 pies 23.7 22.6 28.3 24.4 2.7 7.0

Types.—Holotype: 117816d; figured paratypes: 117816a-c,f; unfigured para-
types: 117816e,g.

Horizon and locality—Decorah formation (Ion member) in Minnesota: From
a road cut 1.1 miles east of U. S. Highway 52 on the south edge of Cannon
Falls ; Fountain and Kenyon, Goodhue County. Twin City Brick Quarry, south-
east St. Paul.

Discussion—This is a fairly large and strongly convex shell broadly and
deeply open when viewed from the side of the brachial valve. It is suggestive
of O. expatiata, and comparison between the two is made under that species.
Compared with other Minnesota species it is larger than O. inquassa and is less
pronouncedly geniculate than that species.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER O13

OPIKINA MAJA Cooper, new species
Plate 236, D, figure 14

Shell large for the genus, subquadrate in outline, with the length and width
nearly equal in the adult; sides gently rounded, subparallel; anterior margin
somewhat narrowly rounded; hinge narrower than the midwidth in the adult
but wider than the midwidth in young; cardinal extremities rounded. Four to
six costellae in 1 mm. at the front margin; posterior margin with oblique
wrinkles.

Pedicle valve fairly evenly convex in lateral profile, with the maximum con-
vexity just anterior to the middle; umbonal and posterior regions swollen; an-
terior profile strongly domed and with long, moderately steep sides. Narrow
swelling at umbo. Median region strongly swollen; anterior slope gently convex
in profile, long and steep; interarea short. Interior with large flabellate muscle
field occupying less than half the inner surface.

Brachial valve with maximum depth at or just anterior to the middle; pos-
terior half gently concave; sides and anterior margin moderately bent in the
direction of the brachial valve.

Measurements in mm.—Holotype, length 42.8, brachial length 40.2, midwidth
43.1, hinge width 32.5?, thickness 9.7, height 17.7.

Types.—Holotype: 117819; unfigured paratype: 117820.

Horizon and locality—‘Lebanon formation” = Ridley formation in Kensing-
ton (T.V.A. 206-SE) Quadrangle, Georgia: From a road cut on U. S. High-
way 27, on the north bank of Chickamauga Creek, 14 miles northeast of Pond
Spring.

Discussion.—This is the largest of the species referred to Opikina. Although
the proportions approach Macrocoelia, the geniculation of the brachial valve as
revealed by a brachial interior (117820a) is like that characteristic of Opikina.

OPIKINA MATUTINA Cooper, new species
Plate 245, C, figures 13-20

Small for the genus, subrectangular in outline; wider than long and with the
hinge forming the widest part; cardinal extremities acute to auriculate; sides
gently rounded; anterior margin broadly rounded; surface costellate as usual
in the genus, about 6 to the millimeter at the front margin. Oblique wrinkles
present on posterior margin.

Pedicle valve unevenly convex in lateral profile with the visceral region occu-
pying the posterior two-thirds, gently convex; angle of geniculation about 100° ;
trail short, steep, and nearly flat in profile; umbo narrowly folded at the beak
and forming a short, indistinct fold; interarea short. Interior with large muscle
field ; diductors subflabellate.

Brachial valve with visceral region flattened but anterior margin strongly
deflected toward the brachial valve to form a deep concavity; sides much less
strongly deflected than the anterior margin; umbo sulcate. Interior with usual
septa thickened and partly covered by adventitious shell.

QOI4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—Holotype, length 12.1, brachial length 11.0, midwidth
14.2, hinge width 15.0, thickness 2.9, height 4.7, trail length 6.0.

Types.—Holotype: 117817a; figured paratype: 117817b; unfigured paratype:
117817¢.

Horizon and locality —Arline formation in Virginia: In Porterfield Quarry,
5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Discussion.—This is one of the earliest members of this genus yet found. The
species is small, geniculate in the anterior third, and has a diamond-shaped
muscle area in the pedicle valve. It is similar to O. parvula but differs in having
pronounced ears, geniculation farther anterior to the beak, and a flatter brachial
valve.

OPIKINA MINNESOTENSIS (N. H. Winchell)
Plate 245, D, figures 21-28

Strophomena minnesotensis N. H. WINcCHELL, 9th Ann. Rep. Minnesota Geol. Nat. Hist.
Surv., p. 120, 1881.

Opikina minnesotensis (N. H. Winchell) Satmon, Journ. Paleont., vol. 16, No. 5, p. 502,
pl. 87, figs. 5-11, 1942 (complete synonymy).

Types.—Hypotypes: 24705, 24708a,b, 45277a-c.

Horizon and locality.—Platteville formation (McGregor member) in Min-
nesota: At Minneapolis; on U. S. Highway 52, 2 to 3 mles north of Fountain,
Goodhue County.

Same formation in Wisconsin: Bluff at Hudson, St. Croix County; Janes-
ville, Rock County; Mineral Point, Iowa County; Bellville, Dane County;
Pomeroy’s Quarry, River Falls, Pierce County; quarry at the junction of Wis-
consin Highways 130 and 23, north of Dodgeville, Iowa County; Rocktown,
Ripon Center, quarry on Wisconsin Highway 81, 1 mile north of Ellenboro,
Grant County; Beloit, Rock County.

Same formation in Illinois: 14 miles northeast of Dixon, Dixon (15’) Quad-
rangle.

Discussion.—This species is similar to O. septata internally and externally,
but the Minnesota species is more convex and has a much larger muscle scar
in the pedicle valve.

OPIKINA NASUTA Cooper, new species

Plate 242, C, figures 11-13a

Shell of about medium size for the genus, slightly wider than long and with
the hinge about equal to the midwidth; cardinal extremities nearly a right angle;
sides gently curved, subparallel; anterior margin narrowly rounded; surface
costellate; visceral region with obscure concentric wrinkles.

Pedicle valve with uneven convexity, the posterior two-thirds nearly flat but
the anterior third abruptly and sharply bent in the direction of the brachial valve.
Anterior profile strongly domed. Angle of geniculation 115°; umbo narrowly
swollen to form a short fold; lateral slopes precipitous ; anterior slope long and
steep; anterior third swollen and narrowed to give a nasute effect to the valve.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER gI5

Muscle area equal in length to about one-third the valve length, deeply bilobed
at the front.

Brachial valve nearly flat to gently convex in lateral profile; sides narrowly
and abruptly bent toward the brachial valve. Interior with prominent, stout but
short septa anterior to the adductor field; septa between adductors stout.

Measurements in mm.—

Brachial Hinge Thick- Height
Length length Midwidth width ness
Holotype (pedicle valve) .......... 19.6 iy ates 19.8 ? 7.3
Paratype (brachial valve 117821b).. ? 15.6 18.2 19.4 ? ?
ff Gis “ET TZSQa) le. coer 14.2 18.6 19.6 ? i

Types.—Holotype: 117821e; figured paratype: 117821a; unfigured paratypes:
117821b-d,f.

Horizon and locality—Chatham Hill formation in Virginia: 1.2 miles $.31°
KE. of Sharon Springs, Burkes Garden (15’) Quadrangle.

Discussion.—The species is different from all other described species except
one. It is characterized by an unusually flat posterior region and a strongly
and abruptly geniculated anterior, which produces a long trail in the pedicle
valve. The only other species suggestive of this one is O. ? dubia, but that is
smaller and has a shorter geniculated region. Interiors of the brachial valve
have the important elements of Opikina.

OPIKINA PARVULA Cooper, new species
Plate 244, A, figures 1-9

Small for the genus, subrectangular in outline, wider than long; hinge nar-
rower than the midwidth; sides subparallel; anterior margin broadly rounded;
4 costellae in I mm. at the anterior margin; posterior margin with short, oblique
wrinkles.

Pedicle valve geniculated anterior to the middle in lateral profile; angle of
geniculation about 115°; anterior profile strongly domed; geniculation occur-
ring at 6 to 8 mm. anterior to the beak; geniculated part narrowly rounded;
visceral region gently convex in lateral profile; anterior slope convex and steep.
Lateral slopes steep. Posterior margin nearly straight; beak small and slightly
protuberant.

Brachial valve with visceral region gently concave; umbonal region concave,
the concavity forming an indistinct sulcus to about the middle; sides moderately,
and anterior strongly, deflected toward the brachial valve to surround the visceral
concave region.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
EVIE jis sie iniess 5.6 0 ae 11.7 10.8 13.5 127 27 4.8
Paratype (117823b)..... 10.2 9.2 pee, 10.2 2.4 4.2
(417822a))ce os 9.8 ? 8.8 ? EL. 12.3 2.0 3.6

Types.—Holotype: 117823a; figured paratype: 117822a; unfigured paratypes:
117822b,c, 117823b,c.

916 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality—Benbolt formation in Virginia: 5 miles northwest of
Wytheville, Wythe County; 4 mile southeast of Green Valley Church, 3 miles
southwest of Lebanon, Brumley (T.V.A. 205-SE) Quadrangle.

Discussion—For comparison with O. bellula and O. dorsatiformis see those
species.

OPIKINA ? PLANULATA Cooper, new species
Plate 247, A, figures 1-4

Shell large for the genus, subquadrate in outline, length slightly less than the
width ; hinge forming the widest part; sides oblique; anterior margin somewhat
narrowly rounded; costellae on pedicle valve numbering 3 to the millimeter at
the front margin, 2 large and I small; brachial valve with somewhat finer cos-
tellae, usually 4 to the millimeter of subequal costellae.

Pedicle valve gently convex in lateral profile with the anterior profile broadly
convex ; umbo narrowly swollen to form a short fold; umbonal slopes descend-
ing gently to the cardinal extremities; median region gently swollen; anterior
slope gently convex but steeper than the longer lateral slopes. Muscle field not
quite reaching the middle.

Brachial valve gently concave in the posterior region and reaching its deepest
part anterior to the middle ; cardinal extremities flattened. Sides gently deflected
toward the brachial valve; anterior margin fairly strongly bent in the direction
of the brachial valve.

Measurements in mm.—

Brachial Hinge Thick- Height
Length length Midwidth width ness
Holotype (pedicle valve) .......... 2 ry 26.9 32.2 ? acc
Paratype (brachial valve 117824b).. ? 28.8 34.4 35.5 ? ?

Types.—Holotype: 117824a; figured paratypes: 117824b-d; unfigured para-
types: 117824e-g.

Horizon and locality.—Pierce formation in Tennessee: At old Pierce Mill
site on Stone River at bridge on Tennessee Highway Io, just south of Walterhill,
7% miles north-northeast of Murfreesboro, Rutherford County.

Discussion—This species is questionably referred to Opikina. It has some
features that suggest Macrocoelia such as the large size and low convexity, but
the small muscle scar in the pedicle valve is not characteristic of Macrocoelia. A
small brachial interior is more suggestive of Opikina. If it belongs to that genus,
it is the least convex of the species discussed herein. If it belongs to Macrocoelia,
it is suggestive of M. bella but is differently shaped and not quite so convex.

OPIKINA PULCHELLA Cooper, new species
Plate 244, B, figures 10-16; plate 246, B, figures 3, 4
Shell small for the genus, longer than wide, and with the hinge forming the
widest part. Sides gently rounded, oblique; anterior margin narrowly rounded

to subnasute ; cardinal extremities nearly a nent angle. Costellate, 4 to 5 costel-
lae in I mm. at the front margin.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER QI7

Lateral profile unevenly convex, narrowly rounded at about the middle, the
angle of geniculation about 95° ; anterior profile narrowly convex ; visceral region
gently swollen and gently convex in profile; anterior slope gently convex but
long and steep; lateral slopes long and steep, about equal to the anterior slope;
interarea moderately long. Interior with elongate diductors and large adjustor
scars; pallial marks well developed.

Brachial valve gently concave in the visceral region; deepest just anterior to
the middle; sides and anterior margin strongly and abruptly bent toward the
brachial valve to surround the visceral region.

Measurements in mm.—Holotype, length 9.5, brachial length 8.6, midwidth
10.4, hinge width 10.5, thickness 4.2, height 6.0.

Types.—Holotype: 117825a; figured paratype: 117825b.

Horizon and locality—Benbolt formation (base) in Virginia: 0.2 mile south
of the middle fork of Moccasin Creek, 14 miles south of Hansonville, Hanson-
ville (T.V.A. 205-SW) Quadrangle.

Discussion.—This species is unlike all others herein described in its small
size and strong convexity. It is much smaller than O. dorsatiformis or O. parvula
which are both small species. The shell is thick and the pallial marks strongly
impressed.

OPIKINA QUADRATA Cooper, new species
Plate 241, B, figures 9-13

Shell of about medium size, with the length and width about equal; sides
gently rounded, subparallel ; anterior margin somewhat narrowly rounded ; hinge
variable, generally less than the midwidth in the adult; costellae numbering
about 3 of the stronger ones to 1 mm. at the front margin.

Pedicle valve fairly evenly and gently convex in lateral profile and with the
maximum convexity just anterior to the middle; anterior profile broadly and
gently convex, not domed ; umbonal region somewhat broadly swollen and mod-
erately elevated above the posterolateral regions; median and anterior region
moderately swollen; anterior slope about equal to the lateral slopes but some-
what steeper. Muscle area large and not quite reaching the middle.

Brachial valve deepest in the midregion but not of great depth anywhere on
the valve; posterior region gently concave and deepening toward the middle;
margins moderately bent toward the brachial valve to form a gently sloping
rim. Interior with septa not strongly developed and adductor ridges and margins
thickened. Subperipheral rim moderately thickened.

Measurements in mm.—

Brachial Hinge Thick-
Length length Midwidth width ness Height
Holotype das ticicicaesiss cass ? 20.0 21.5 20.5 ? ?
Paratype (117826a)...... ? 19.3 20.3 21.7 ? ?
Ht (117826b)...... 20.5 ? 23:4 20.6 P 5.3
4 (117826) 2s42 ? 19.1 20.0 21.9 ? ?
i’ (7178260) )s.\2.5: 20.0 f 20.9 19.4 ? 4.3

918 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 117826e; figured paratypes: 117826b,d,f; unfigured para-
types: 117826a,c.

Horizon and locality—Top of the Ridley formation in Tennessee: On east
side of Marshall Knobs, 5 miles south of Murfreesboro, Murfreesboro (15’)
Quadrangle.

Discussion.—This species is characterized by low convexity and nearly square
outline. It differs from O. speciosa in its lesser convexity and the flatness of the
brachial valve. It approaches O. subplanodorsata but is even flatter than that
species.

OPIKINA SEPTATA Salmon
Plate 230, B, figures 8-28
Opikina septata SALMON, Journ. Paleont., vol. 16, No. 5, p. 591, pl. 87, figs. 1-4, 1942.

Types—Holotype: 117829c¢; paratypes: 117829a,b; figured hypotypes:
117827a,b, 117828, 117830.

Horizon and locality—Lebanon formation (upper half=Doleroides zone) in
Tennessee: On U. S. Highway 41, # mile south of Knox Branch, 9 miles
southeast of Murfreesboro; U. S. Highway 70S, 0.8 mile west of Dry Branch
of Cripple Creek; cut on U. S. Highway 241, 2.1 miles north of Bedford County
line; U. S. Highway 41, 14 miles northwest of Mount Olivet, 10 miles southeast
of Murfreesboro; Rutherford County. On U. S. Highway 70N opposite Fair-
view Service Station, 4 mile west of Rome, Smith County; on U. S. Highway
70S, + mile east of Readyville, Woodbury (15’) Quadrangle; Columbia, Maury
County ; Lebanon, Wilson County.

Discussion.—This species is characterized by its wide hinge and low convexity.
It is quite different from O. transversa of the Wardell formation of Rye Cove
which is much more convex and often more transverse. Opikina septata is sug-
gestive of O. minnesotensis, but that species is differently shaped, less alate, and
has a much larger muscle area in the pedicle valve.

OPIKINA SPECIOSA Cooper, new species

Plate 237, A, figures 1-19; plate 238, A, figures 1-7; plate 241, D, figures 20-28;
plate 247, FE, figures 14-16; plate 249, A, figures 1-9

Shell of about medium size for the genus; subrectangular in outline; wider
than long and with the hinge usually forming the widest part ; cardinal extremi-
ties subauriculate; sides slightly oblique; anterior margin narrowly rounded;
costellae differentiated into strong and fine, numbering about 4 to the millimeter
at the front margin; concentric fila strong. Concentric oblique wrinkles mark
the posterior margin.

Pedicle valve fairly strongly convex in lateral profile and with the maximum
convexity located just anterior to the middle; posterior three-fifths gently con-
vex in lateral profile; anterior two-fifths strongly bent at an angle varying from
100° to 120° toward the brachial valve; anterior slope rounded and steep; lat-
eral slopes longer than the anterior one and much less steep. Interior with muscle

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 919

field occupying about half the interior, extending from the delthyrial cavity to
the place of geniculation. Thin median septum prominent.

Brachial valve gently concave in the posterior three-fifths but with the lateral
and anterior margins strongly bent in the direction of the brachial valve; greatest
depth just anterior to the middle. Interior with septa subdued but well de-
veloped ; cardinal process stout ; subperipheral rim thick and beaded.

Measurements in mm.—
Brachial Hinge

Length length Midwidth width Thickness Height
AMOUVE Az sce + oun ae be eae 23.1 20.9 26.6 30.0 5.6 0.9
Paratype (117837a)..... 20.8 19.1 21.6 21.9 5.2 9.5
si Crrz837b ee. 21-2 19.8 22.6 ? 4.0 7.8
" C1i7836b) eas 4% Piet 10.7 24.1 24.8 3.0 6.3
, (TIvSage)ii ee, 21.5 19.7 Baus 26.8 4.8 8.8
% (Guiztee ei) Rar 20.2 19.0 22.9 24.4 3.0 7.9
a CEr7Zojea) ess. 27 ? 23.5 23.1 ? ?
re (117839d)..... 20.0 18.7 23.0 24.4 5.0? 77
‘ (1178390b)..... 24.1 227, 26.2 27.0 4.9 10.3 ?

Types.—Holotype: 117835a; figured paratypes: 117831b, 117833a,c-e,
117834a,b,e, 117835b,d, 117836a, 117837a-c, 117838a, 117839b,e,f,h,i ; 123287b;
unfigured paratypes: 117831a, 117832a-f, 117833b, 117834c,d, 117835¢c,e,f,
117836b, 117838b, 117839a,c,d,g, 1232872.

Horizon and locality.—Ridley formation in Tennessee: 0.6 mile south of Chap-
pel Hill Methodist Church on Tennessee Highway 28, 1 mile south of its junc-
tion with Tennessee Highway 8, Daus (T.V.A. 104-SW) Quadrangle.

Wardell formation and Wardell part of Dryden formation in Tennessee: North
of the canyon of Gap Creek, Powell Valley, military coordinates 790250N,
2677730E, 14 miles west of Arthur, Cumberland Gap (T.V.A. 153-SW) Quad-
rangle; Jacksboro, Jacksboro (T.V.A. 136-SW) Quadrangle; road at the base
of Cedar Ridge 3 mile southeast of Litton, Sequatchie Valley, Pikeville Special
(15’) Quadrangle; Lone Mountain, Tazewell (T.V.A. 154-NE) Quadrangle;
U.S. Highway 25E, 4 mile north of Indian Creek, Evans Ferry section, Howard
Quarter (T.V.A. 162-NW) Quadrangle; on old Tennessee Highway 33,
0.3 mile southwest of Little Barren Church, Powder Springs (T.V.A. 154-SW)
Quadrangle; Tennessee Highway 33, 5 mile west of the cemetery at the bend
below Kecks Mill, Powder Springs (T.V.A. 154-SW) Quadrangle; 2 miles
northeast and 1 mile west of old Tazewell, Tazewell (T.V.A. 154-NE) Quad-
rangle; back of Camp Loyston, Maynardville (30’) Quadrangle.

Same formation in Virginia: In the north quarry on Station Creek, 4 mile
south of U. S. Highway 58, 2 miles east of Cumberland Gap, Wheeler (T.V.A.
153-SE) Quadrangle.

Ridley formation in Murfreesboro (15’) Quadrangle, Tennessee: In the
lower third of the formation on the east side of Marshall Knobs, 5 miles south
of Murfreesboro; Bradleys Creek 1 mile east of Murfreesboro.

Pierce formation in Tennessee: Bradleys Creek, 1 mile east of Lascassas,
Rutherford County.

920 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

“Lebanon” limestone= Ridley formation= Wardell formation in Georgia: In
a quarry 14 miles south-southeast of Cove Church, Kensington (T.V.A. 206-SE)
Quadrangle; on U. S. Highway 27, 1 mile north of Rock Spring, Nickajack Gap
(T.V.A. 113-SW) Quadrangle.

Discussion—This species is abundant and widespread in the Wardell forma-
tion in Virginia and Tennessee. It resembles O. transitionalis Okulitch, but sig-
nificant differences between the two species can be detected. Opikina speciosa as
defined and identified herein is a variable species and may ultimately be further
split. The specimens from the Ridley formation of the central basin of Tennessee
appear to be somewhat narrower than those from the Wardell formation along
the Cumberland Front and in Sequatchie Valley. However, length-width index
of these narrow forms differs 0.07 from the broadest specimens.

Opikina speciosa is suggestive of O. transitionalis, O. inquassa, and O. formosa.
Comparison with the last species is made above. From O. inquassa the Appa-
lachian species differs in having its geniculation farther anterior to the beak than
in the Minnesota species. Thus the maximum convexity is farther anterior than
in the Minnesota species. The anterior trail of O. speciosa is more swollen and
steeper than that of O. inquassa. According to Salmon (1942, p. 596) O. transi-
tionalis possesses “sharply projecting ears and a sinuous lateral margin.” These
are not features of O. speciosa. Dr. Salmon states further that the genicula-
tion in O. inquassa occurs farther toward the anterior than in O. transitionalis.
This feature makes comparison with O. speciosa still more remote because its
geniculation takes place farther anterior than it does in O. inquassa.

Opikina speciosa is more strongly geniculated and farther from the beak than
in O. lirata. The Oklahoma Opikinas are all different from O. speciosa.

OPIKINA SUBPLANODORSATA Cooper, new species
Plate 241, C, figures 14-19

Shell of about medium size for the genus, subquadrate; slightly wider than
long, the hinge usually narrower than the width at the middle; sides gently
rounded, subparallel; anterior margin narrowly rounded; cardinal extremities
obtuse. Costellae fine and thin, 3 or 4 to a millimeter at the front margin.

Pedicle valve unevenly convex in lateral profile, the posterior three-fifths
nearly flat except near the beak where it is somewhat swollen ; anterior two-fifths
gently rounded but forming a fairly steep anterior slope bent about 115° from
the posterior part. Geniculation prominent in the adult; sides with moderately
steep slopes.

Brachial valve gently and evenly concave throughout its length; maximum
concavity located at the middle or slightly anterior to it. Sides and anterior
margins bent only slightly toward the brachial valve.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height

15) (0) 4 0 a a 22.7 21.0 24.6 20.4 6.3 8.2
Paratype (117840c)..... 21.8 IG.8) \\\0\ e630 22.0 5.6 7.4

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER g2I

Types—Holotype: 117840a ; figured paratype: 117840b; unfigured paratype:
117840.

Horizon and locality Wardell formation in Tennessee: On the north side
of the road 1.1 miles northeast of Lee Valley, Lee Valley (T.V.A. 171-NW)
Quadrangle; 2 miles northeast of Thorn Hill, Avondale (T.V.A. 162-SW)
Quadrangle.

Davis’ store, 5 miles west of Eidson, Hawkins County; military coordinates
719410N, 2746920F, hill west of west fork of center branch of Notchy Creek,
Avondale (T.V.A. 162-SW) Quadrangle.

Same formation in Virginia: 4 mile west of the Danlboone Siding on U. S.
Highway 58, Gate City (T.V.A. 188-NE) Quadrangle.

Discussion.—This species is similar to O. speciosa and to O. inquassa but
differs from both of them in having the brachial valve gently concave.

OPIKINA TRANSITIONALIS (Okulitch)

Rafinesquina transitionalis OkutitcH, Canadian Field-Nat., vol. 49, No. 6, p. 97, pl. 1,
figs. 3, 4, 1935.

Opikina transitionalis (Okulitch) SAtmon, Journ. Paleont., vol. 16, No. 5, p. 505, pl. 87,
figs. 15-18, 1942-—Witson, Geol. Surv. Canada, Bull. 8, p. 93, 1946 (specimen figured
rejected by Salmon and placed in O. wagneri (Okulitch) ).

Types.—Holotype: Peter Redpath Mus., McGill Univ., Montreal.

Horizon and locahity.—Lowville and Leray formations in Quebec: At Pointe
Claire. “One of the most common species of Opikina in North America” accord-
ing to Salmon (1942, p. 590).

Discussion.—This species has been widely identified by Salmon and others
from Middle Ordovician rocks, but the species could not be identified in any of
the collections herein described. It is suggested that its affinities are with the
more northern areas of outcrop of Black River-Early Trenton strata.

OPIKINA TRANSVERSA Cooper, new species
Plate 244, C, figures 17-32

Shell small for the genus, wider than long and with the hinge usually form-
ing the widest part ; cardinal extremities subauriculate ; sides gently rounded and
oblique ; anterior margin broadly rounded; finely costellate, 2 or 3 of the larger
costellae occupying I mm. at the front margin. Posterior margin with oblique
wrinkles.

Pedicle valve strongly but unevenly convex in lateral profile, the maximum
convexity located at or just anterior to the middle; anterior broadly and usually
strongly domed; visceral region gently to moderately convex; geniculated por-
tion somewhat narrowly rounded about half the surface length of the pedicle
valve to the beak. Anterior slope gently convex, steep and longer than the lat-
eral slopes which are also steep. Interarea short.

Brachial valve with visceral region gently concave and surrounded by the
strongly curved lateral and anterior margins. Brachial valve deepest just anterior
to the middle.

Q22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
FAQIGUS PE... 0 a oeeeet ats 16.1 14.4 20.5 20.2-++ 3.9 7.4
Paratype (117844b)..... 16.5 14.8 21.0 20.0 4.2 6.9
4 (117844d)..... 13.0 12.0 16.6 16.8 32 5.0
“5 (TI7845a) 20.2 15.8 14.6 19.1 20.2 2.8 5.1
= (117843b)..... 14.5 13.3 18.0 17.3 2.6 5.0
: (117843c) .'.... 13.8 17 Lig: ? 3.0 5.6
« (ua7B40a)E s8 11.8 11.2 16.7 20.4 1.6 2.5
‘ (117846c)..... 14.1 13.1 18.3 17.5 3.0 5.8
ie (TI7SA5a) steht 19.9 18.3 27 2 23.7 4.4 10.0
ie (117842)... hse 17.4 16.4 22.5 26.1 2.4 5.7

Types.—Holotype: 1178442 ; figured paratypes : 98226a,b, 117843d, 117846a-d,
123276a; wunfigured paratypes: 98226c-h, 117842, 117843a-c, 117844b-d,
117845a-f, 117846e, 123276b.

Horizon and locality—Wardell formation and Wardell part of Dryden forma-
tion in Tennessee: Lloyd Carter’s barn, 0.8 mile by road northeast of Rye Cove
School ; second road cut west of L. McDavid’s house, 1 mile west of Rye Cove;
Clinchport (T.V.A. 188-NW) Quadrangle.

Discussion.—This is a variable species ranging from extremely transverse
shells to ones that are nearly square in outline. This species is smaller, wider,
and more convex then O. speciosa and formosa. It is larger and more convex
than O. parvula and is shaped and ornamented differently from O. bellula. Be-
sides being very differently shaped, it is more convex and also more deeply con-
cave than O. minnesotensis to which it has mistakenly been referred. The shell
geniculates nearer the beak than in O. varia.

OPIKINA VARIA Cooper, new species
Plate 240, A, figures 1-7
Rafinesquina aff. minnesotensis Butts (not Winchell), Alabama Geol. Surv., Special Rep. 14,
p. 126, pl. 31, figs. 23, 24, 1926.

Shell small for the genus, subquadrate to subrectangular in outline, slightly
wider than long; sides gently rounded, subparallel; anterior margin broadly
rounded. Hinge generally equal to or less than the width at the middle. Costellae
well differentiated, 2 of the larger size in 1 mm. at the front margin. Larger
costellae separated by 2 to 4 of the finer ones.

Pedicle valve unevenly convex in lateral profile, with the maximum convexity
anterior to the middle; anterior profile moderately domed ; geniculation occurring
about II mm. anterior to the beak; angle of geniculation 115°; visceral region
varying in lateral profile from nearly flat to moderately convex; anterior slope
gently convex, short and steep; sides with short and steep slopes; interior with
muscle field to about the middle of the valve.

Brachial valve gently concave in the visceral region which extends for about
3 the length ; deepest part anterior to middle; sides and anterior margin narrow
and abruptly bent in the direction of the brachial valve.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 923

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
FEPOUGEG PE ates aloes oh. a siaiw's TS 13.6 GRE: 18.0 4.5 6.9
Paratype (71350a)...... 15.1 5 17.3 16.6 ? 5.0

Types.—Holotype: 117848a ; figured paratypes : 71350a,b, 117847a,c, 117848b ;
unfigured paratypes: 117847b, 117848c-e.

Horizon and locality—Carters formation in Alabama: In the Ovoplecia beds
from the quarry 0.3 mile north of Gate City, Leeds (15’) Quadrangle; Cedar
Mountain, 2 miles southwest of Argo, Birmingham (30’) Quadrangle.

Dryden formation in Virginia: In the vicinity of Rye Cove, Clinchport
(T.V.A. 188-NW) Quadrangle.

Dryden formation in Tennessee: On the Lone Mountain to Tazewell road, 13
miles northeast of Lone Mountain, Tazewell (T.V.A. 154-NE) Quadrangle;
on Little Sycamore Creek, $ mile northeast of the west edge of the Howard
Quarter (T.V.A. 162-NW) Quadrangle.

Discussion.—This is a species of moderate size which is variable and without
any one mark of distinction. It is about the size of O. bellula but differs from that
species in convexity and character of ornamentation. It differs from O. trans-
versa in being only moderately extended along the hinge and in having its con-
vexity farther anterior than that of O. transversa which has its convexity near
the middle. Opikina varia differs from O. minnesotensis in having its maximum
convexity posterior to that of the Minnesota shell.

OPIKINA WAGNERI (Okulitch)

Rafinesquina wagneri OkuLitcH, Canadian Field Nat., vol. 49, No. 6, p. 98, pl. 1, fig. 5, 1935.

Opikina wagnerit (Okulitch) Satmon, Journ. Paleont., vol. 16, No. 5, p. 506, pl. 87, figs. 19-27,
1942.—WItson, Geol. Surv. Canada, Bull. 8, p. 94, pl. 8, figs. 14a, b, 1946.

R. transitionalis (Okulitch) part, idem, p. 97, pl. 1, fig. 4 (not fig. 3), 1935.

R. williamsi OxutircH, idem, p. 98, pl. 1, fig. 6, 1935.

Type.—Holotype: Peter Redpath Mus., McGill Univ., Montreal.
Horizon and locality—Leray = Chaumont formation in Quebec: At St. Vin-
cent de Paul.

OPIKINA in Canada

Dr. Alice Wilson in 1944 described many species of Opikina from the Leray-
Rockland beds of the Ottawa St. Lawrence Lowland. These species appeared
first in Transactions of the Royal Society of Canada, ser. 3, vol. 38, sec. 4, 1944,
and later in Geological Survey of Canada, Bull. 8, 1946. The species are listed
below in alphabetical order. The first set of figures are the page and plate refer-
ences to the Royal Society of Canada publication, and the second set of figures
refer to the Geological Survey of Canada paper.

Opikina ampla Wilson, p. 190, text fig. 10, No. 12, pl. 2, fig. 26.
p. 89, text fig. 10, No. 12, pl. 6, fig. 29.
O. gloucesterensis Wilson, p. 191, text fig. 10, No. 4, pl. 2, fig. 10.
p. 80, text fig. 10, No. 4, pl. 6, fig. 20.

924 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

O. hemispherica Wilson, p. 192, text fig. 10, No. 11, pl. 2, fig. 20.
p. 90, text fig. 10, No. 11, pl. 6, fig. 21.
O. ovalis Wilson, p. 192.
p. 90, pl. 8, fig. 20, 21.
O. platys Wilson, p. 1093, text fig. 10, No. 3, pl. 2, figs. 21, 21b.
p. OI, text fig. 10, No. 3, pl. 6, figs. 22, 23.
0. rugosa (Wilson), Geol. Surv. Canada, Bull. 33, p. 51, pl. 3, figs. 8, 9, 1921.
p. 194, text fig. 10, No. 1.
p. 91, text fig. 10, No. 1, pl. 8, figs. 22, 23.
O. (?) rugosa avita (Wilson), Canadian Field Nat., vol. 46, No. 6, 1932.
p. 138, pl. 2, figs. 6-13.
p. 195, text fig. 10, No. 2.
p. oI, text fig. 10, No. 2, pl. 8, figs. 15-19.
. septata borealis Wilson, p. 195, text fig. 10, No. 6, pl. 2, fig. 15.
p. 92, text fig. 10, No. 6, pl. 6, fig. 15.
. sinclairi Wilson, p. 196, text fig. 10, No. 9, pl. 2, figs. 18a, b.
p. 92, text fig. 10, No. 9, pl. 6, figs. 18, 19.
. subtriangularis Wilson, p. 196, text fig. 10, No. 5, pl. 2, fig. 22.
p. 92, text fig. 10, No. 5, pl. 6, fig. 24.
. tumida Wilson, p. 197, text fig. 10, No. 10, pl. 2, fig. 16.
p. 93, text fig. 10, No. 10, pl. 6, fig. 16.
. wagneri robusta Wilson, p. 198, text fig. 10, No. 8, pl. 2, figs. 25a, 25b.
p. 94, text fig. 10, No. 8, pl. 6, figs. 27, 28.

Of OO 2 Os =

GPIKINA sp. 1
Plate 242, A, figures 1-5

This is a species characterized by low convexity and not strongly pronounced
geniculation. It somewhat resembles O. subplanodorsata but is more concave.
It is also suggestive of O. varia, but the place of geniculation is farther from the
beak and the ornamentation is different.

Measurements in mm.—117849, length 14.5, brachial length 13.4, midwidth
15.1, hinge width 15.9, thickness 3.3, height 4.8.

Figured specimen.—117849.

Horizon and locality.—Benbolt formation in Virginia: On the east bank of a
sinkhole south of Lakeview Church on Virginia Highway 71, southwest quar-
ter of east-central subquad., Moll Creek (T.V.A. 196-SE) Quadrangle; 14 miles
southwest of Rye Cove, Clinchport (T.V.A. 188-NW) Quadrangle.

OPIKINA sp. 2

This is a small species elongate or subquadrate, of modest height and depth
and with geniculation occurring at Io to 13 mm. anterior to the beak. It is sug-
gestive of O. parvula, but the Oklahoma shell is not so deep and is somewhat
differently proportioned. This Oklahoma species is smaller than O. varia and
differently proportioned.

Measurements in mm.—117850, length 16.5, brachial length 15.6, midwidth
16.2, hinge width 13.8, thickness 3.0, height 5.1.

Described specimen—117850.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 925

Horizon and locality—Bromide formation (Pooleville member-zone 2) in
Oklahoma: West of Nebo store, sec. 22, T. 2 S., R. 3 E., Murray County.

6PIKINA sp. 3

This is a species of medium size having fairly low convexity, prominent beak,
and narrowly swollen umbo. The posterior half is characterized by costellae al-
ternating in size, but at the anterior the costellae are nearly equal and number 4
to the millimeter. The specimen is not like any other in the collection but is not
complete enough for specific designation.

Measurements in mm.—117851, length 18.0, midwidth 21.5, hinge width
20.3?, height 4.5 ?.

Described specimen.—117851.

Horizon and locality—Edinburg formation (Cyrtonotella zone) in Virginia:
In the railroad cut about $ mile east of Strasburg Junction, Strasburg (15’)
Quadrangle.

OPIKINA sp. 4

A single specimen of fairly large size for the genus, having a somewhat nasute
front and considerable height, is so poorly preserved that specific description is
inadvisable. The specimen is significant, however, because of its occurrence in
the Little Oak limestone. It is suggestive of some from the Ridley of West
Tennessee.

Measurements in mm.—123295, length 22.8, brachial length 19.7, midwidth
23.0?, thickness 4.1, height 10.4.

Described specimen.—123295.

Horizon and locality—Little Oak formation in Alabama: At the junction of
the Bailey Gap and Cahaba Valley roads, SWiSW3 sec. 13, T. 19 S., R. 2 W,,
13 miles northeast of Newhope Church, Vandiver (15’) Quadrangle.

OPIKINA sp. 5
Plate 268, E, figures 16-24

This is a variable or possibly a mixed species that occurs abundantly in the
Whistle Creek formation of Catawba Valley. It is moderately large, fairly
strongly convex, and with the convexity just anterior to the middle. The brachial
valve is deeply concave. The muscle field of the pedicle valve is nearly circular
and of moderate size. The species is quite unlike either of the Arline species
and appears remarkably advanced for the earliest Opikina.

Measurements in mm.—123292a, length 18.7, brachial length 17.1, midwidth
22.5, hinge width ?, thickness 3.7.

Figured specimens.—123292a-d.

Horizon and locality.—Ellett formation (75 feet above the Knox dolomite)
in Virginia: On Indian Run, # mile northwest of Lusters Gate, Blacksburg (15’)
Quadrangle.

Discussion—Unfortunately, the material collected is not good enough on

926 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

which to establish a species, and the interior of the brachial valve is unknown.
This is the earliest Opikina known.

Genus STROPHOMENA Blainville, 1825

Strophomena BLAINvILLE, Man. Malacol., vol. 1, p. 513, 1825—HALt and CriarkeE, Pal. New
York, vol. 8, pt. 1, p. 245, 1892.

Opikina Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 38, sec. 4, p. 190, 1944; Geol. Surv.
Canada, Bull. 8, p. 95, 1046.

Strophomena is an abundant brachiopod throughout rocks that are here as-
signed to the Wilderness and Trenton stages. This name is applied to convexi-
concave brachiopods having moderately large muscle fields in the pedicle valve
which are partially surrounded by a thickening extending anteriorly from the
dental ridge. Inside the brachial valve the cardinalia are generally small and
delicate, the median ridge short, and pallial marks not well impressed. Com-
parison with the genotype, Strophomena planumbona (Hall), shows essential
agreement in most of the important details. Nevertheless, a fair variety of forms
has been brought together here under the name Strophomena. Ultimately, some
splitting of groups is likely, but the collections available in this study are too few
to make any progress along these lines possible.

The National Collection is not well provided with specimens of Strophomena
except from a few localities. The collections from the Arbuckles are excellent,
but those from the Appalachians are good from only a few places. Wardell and
Ridley specimens are numerous, but only a few of quality have been taken from
the Witten or higher beds. Good material from the Central Basin of Tennessee
was studied, but the collections from New York and Ontario are meager indeed.

The only regions in which a notable number of species of Strophomena have
been described are the region about Ottawa, Ontario, and the Plattin area of
eastern Missouri. The Ontario Black River and Trenton faunas were described
by Dr. Alice E. Wilson. Many species of Strophomena are described, and two
genera have been split off from it. In general, the species are not adequately
illustrated, and the original specimens show evidence of exfoliation. This is not
ideal material for constructing new species. It has therefore not been possible to
identify any of the Wilson species outside of New York and Ontario.

Similar remarks may be applied to Fenton’s descriptions of species of Stropho-
mena from the Plattin of the Ste. Genevieve County area in eastern Missouri.
The material illustrated by Fenton is good but the illustrations feature chiefly
interiors of pedicle valves and occasional other views. No profiles are given, and
great reliance is put on the interior of the pedicle valve. Fenton relegates a posi-
tion of unimportance in the classification of species to the shape of the shell,
wrinkling of the cardinal extremities, the costellation, and thickness. The writer
believes that even the muscle scars of the pedicle valve of this genus are not re-
liable because they are so variable. Total available features must be taken into
account in defining a species of this genus. Few of Fenton’s species are recog-
nizable in the Appalachians.

Black River and Trenton Strophomena must some day be studied as a whole

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 927

to make the group useful, but the study will require enormous collections which
are not now available.

STROPHOMENA ANOMALA Cooper, new species
Plate 264, A, figures 1-15

Shell small for the genus, wider than long; subrectangular in outline; hinge
equal to or less than the midwidth; sides gently rounded; anterior margin
broadly rounded. Surface costellate, costellae of unequal size, intercalated in
several generations and numbering 3 to the millimeter at the front margin.

Pedicle valve unevenly convex in lateral profile, the posterior half gently con-
vex but the anterior half gently concave. Umbonal region narrowly swollen and
forming a prominent narrow fold to about the valve middle or shortly beyond;
flanks bounding fold forming long, flat to slightly concave slopes to the lateral
margins; anterior third gently concave to flat; interarea long; pseudodeltidium
prominent and swollen.

Brachial valve very gently convex in lateral and anterior profiles; umbo and
median region marked by a shallow and narrow sulcus which disappears in the
slight swelling to form the flattened anterior third ; flanks bounding sulcus slightly
swollen ; posterolateral slopes gentle ; cardinal extremities flattened and deflected
slightly in the direction of the brachial valve.

Pedicle interior with muscle area nearly equal in length and width, but the
anterior ends of the diductor scars elongated; dental ridges thick but not ex-
tended anteriorly around the adjustor-diductor scars. Brachial valve with small
cardinal process but median ridge moderately long and stout.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype. i. «cede seas 12.4 11.2 17.6 17.6 2.8
Paratype (11770I1d).. 11.3 10.5 15.1 13.7 2.0

Types.—Holotype: 117700; figured paratypes: 117701a,c,d; unfigured para-
types: 117700b, 117701b.

Horizon and locality—Benbolt formation (base) in Virginia: 0.2 mile south
of the middle fork of Moccasin Creek, 14 miles south of Hansonville, Hanson-
ville (T.V.A. 205-SW) Quadrangle.

Discussion —This is a rare species known only from the Benbolt formation.
It is characterized by fairly strong costellae, a strong median fold in the posterior
half of the pedicle valve, and nearly even depth of both valves. The species sug-
gests Pionomena but is actually resupinate although not strongly so. This latter
feature will distinguish it from the other members of the genus described herein.
Strophomena ? emaciata Winchell and Schuchert from Minnesota is still more
biconvex and differently ornamented, so that little confusion will result between
these two,

928 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

STROPHOMENA AUBURNENSIS Fenton
Plate 257, A, figures 1, 2; plate 263, C, figures 17-22

Strophomena auburnensis Fenton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 148, pl. 9,
figs. I-3, 1928.

This species is a large one characterized by important exterior and interior
details. The pedicle valve is completely concave except for the umbonal region
which is slightly swollen or flat. The brachial valve is flattened in the posterior
third when viewed in lateral profile, but the anterior two-thirds is fairly strongly
convex. The pseudodeltidium is subcarinate like that of S. crassicostellata Cooper.
The surface is marked by costellae of unequal size, strong costellae setting off
groups of finer ones, as many as 5 of the finer ones in a group.

Inside the pedicle valve the muscle area is quite distinctive. Its length and
width are about equal, and the sides are nearly straight, so that the field is like
a small square with one angle in the delthyrial cavity, the two lateral ones nar-
rowly rounded and the fourth directed anteriorly. Inside the brachial valve the
brachiophores are rudimentary and enclosed in a small cup of adventitious shell ;
the cardinal process is delicate and the median ridge short.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Hypotype (117704a)..... 27:3 2 25.6 ? 36.0 35.6 ?
. CTI7704D) ic. 25.1 ? 32.8 34.9 ?
“ (TV77OZ es 35.8 34.7 45.0 47.6 7.8

Types.—Figured hypotypes: 117702, 117704a,b.

Horizon and locality —Auburn chert in Missouri: $ mile east of Auburn, Els-
berry (15’) Quadrangle. Platteville formation: On Wisconsin Highway 81,
2 miles northwest of Platteville, Mineral Point (30’) Quadrangle; 0.7 mile
northeast of Dickeyville on Wisconsin Highway 151, Grant County.

Decorah formation (Guttenburg member) in Wisconsin: 0 to 8 feet above
8-inch blue clay on top of Platteville, Wisconsin Highway 81, 0.1 mile south of
the Little Platte River, 2 miles northwest of Platteville, Mineral Point (30’)
Quadrangle.

Decorah formation (Spechts Ferry member—Glass Rock) in Illinois: 14 miles
northeast of Dixon, Dixon (15’) Quadrangle.

Discussion—tThis species is characterized by large size and strong differenti-
ation of its costae. It is a large and striking species and evidently at times has
been confused with S. filitexta Hall.

STROPHOMENA AUBURNENSIS IMPRESSA Raasch

Strophomena auburnensis impressa Raasch, in SHRocK and RaAscH, Amer. Midland Nat.,
vol. 18, No. 4, pp. 549, 592, pl. 4, figs. 6, 8, 1937.

Horizon and locality.—Platteville formation (upper Buff) in Wisconsin: At
Beloit, Rock County; 3 miles south of New Glarus, Green County.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 929

STROPHOMENA AUBURNENSIS NASUTA Cooper, new subspecies
Plate 257, B, figures 3-12
Strophomena incurvata Forrste (not Shepard), Bull. Sci. Lab., Denison Univ., vol. 17, p. 24,

pl. 11, fig. 7, 1I912—Butrts (not Shepard), Alabama Geol. Surv., Special Rep. 14, pl. 31,
figs. 25-27; pl. 33, figs. 3, 4, 1926.

Shell large for the genus, subrectangular in outline; hinge usually forming
the greatest width; sides nearly straight; anterior margin strongly rounded and
generally somewhat nasute. Costellae unequal in size, 1 or 2 fine ones alternat-
ing with stronger ones, and 13 to 16 costellae occupying 5 mm. at the front
margin.

Pedicle valve deeply concave in lateral profile and with the maximum con-
cavity in the median region; umbonal region marked by a low and narrow fold
that disappears at about one-third the length from the beak; posterior third
gently concave, median third deeply concave and anterior third less concave than
the preceding. Sides and anterior strongly reflected toward the pedicle valve.
Cardinal extremities more or less auriculate, deflected sharply toward the brachial
valve ; interarea moderately long, strongly apsacline.

Brachial valve unevenly convex in lateral profile, the posterior third flattened
but the anterior two-thirds strongly convex ; anterior profile strongly and broadly
convex; umbo marked by a fairly wide but shallow sulcus that extends nearly
to the valve middle; posterior third flattened ; anterior two-thirds strongly swol-
len and with steep lateral and anterior slopes. Posterolateral slopes long but only
moderately steep; cardinal extremities strongly deflected toward the brachial
valve.

Interior of pedicle valve with large subcircular to quadrate muscle scar, the
anterior end of which reaches to about the valve middle; teeth and dental ridges
strong; sides of muscle field with a thick and strongly elevated rim reaching
nearly to the front of the scar. Subperipheral rim thick and beaded by numerous
pallial distributaries. Brachial interior with short, stout cardinal process and
delicate socket cups. Median ridge short.

Measurements in mm.—
Brachial Hinge

Length length Midwidth width Thickness
FIGIGty Pee ens a eaties cep eioees 20.4 28.6 37.0 35.2 5.8
Paratype'*(45507b)'...'2 2 S22) 2! 26.5 ? 28.3 31.6 ?
“ (87008) Hsia. 28% 32.0 ? 36.4 40.7 ?

Types.—Holotype: 45507a; figured paratypes: 45507b, 87091, figured hypo-
type: 117703a; unfigured paratypes: 45507c,d.

Horizon and locality—Tyrone formation in Kentucky: At High Bridge,
Harrodsburg (30’) Quadrangle.

Carters formation in Tennessee: On the north side of U. S. Highway 70S,
0.8 mile east of Readyville, Rutherford County; McKnights Branch, 2 miles
west of Willow Swamp School, Woodbury (15’) Quadrangle; 1 mile east of
Mount Carmel Church, same quadrangle; road crossing Watson Branch, 4 mile
southwest of Conico Church, Franklin (15’) Quadrangle; on U. S. High-

939 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

way 70N, just east of Round Lick Creek, Rome, Smith County; F. B. Cooper
farm 2 miles southeast of Pikeville, Pikeville Special (15’) Quadrangle ; Auburn,
Cannon County.

Carters formation in Alabama: Quarry 4 mile northeast of Gate City, Leeds
(15’) Quadrangle; ? Birmingham, Birmingham (30’) Quadrangle.

Discussion.—This subspecies is distinguished from other members of the
species by the narrowed and nasute front. This is especially seen in the pedicle
valves.

STROPHOMENA BASILICA Cooper, new species
Plate 258, A, figures 1-17

Shell of about average size for the genus, wider than long; subrectangular in
outline; hinge equal to the midwidth or forming the greatest shell width; sides
nearly straight but generally indented more or less strongly just anterior to the
cardinal extremities; anterior margin strongly rounded; cardinal extremities
varying from nearly a right angle to auriculate. Surface finely costellated, the
costellae of 2 sizes, I to 3 of the finer ones alternating with the stronger ones;
18 costellae may be counted in the space of 5 mm. at the front, the figure includ-
ing 5 of the stronger costellae.

Pedicle valve gently concave in lateral profile; umbonal region slightly con-
vex, the convexity continued anteriorly for a short distance only; cardinal ex-
tremities flattened and deflected slightly toward the brachial valve; greatest con-
cavity in the median region with the sides gently deflected toward the pedicle
valve. Pseudodeltidium long, subcarinate ; foramen minute ; interarea moderately
long.

Brachial valve unevenly convex in lateral profile, the posterior third flat and
the anterior two-thirds moderately convex; anterior profile broadly and moder-
ately convex. Posterior third flattened but with umbo concave, the concavity
extended anteriorly nearly to the middle as a shallow and narrow sulcus ; median
half fairly strongly swollen; anterior slope convex, long, and steep. Lateral
slopes shorter than the anterior one and moderately steep.

Interior of pedicle valve with variably shaped muscle field ranging from nearly
circular to elongate oval; teeth small; dental ridges slender, flaring; ridges sur-
rounding sides of muscle field low and not elevated anterior to the middle of the
field. Interior of brachial valve with brachiophores nearly obsolete; sockets
formed by short, delicate cups; cardinal process small and delicate. Median
ridge low but long, extending for about a third the length.

Measurements in mm.— Brachial

Hinge
Length length Midwidth width Thickness
PIONOLY DE ce ceeh see wane stain 27.8 26.5 34.5 32.6 4.0
Paratype: (117705b)2 3...4 ee ? 26.1 32.0 31.1 ?
‘ (1177050) 2 v22.. KIN 227, ? 26.9 26.5 ?
i (BE7FOSA) ohh» 5 antes ? 22.0 25.8 26.7 ?
ih CEIZ7O5E ) cto ok bua 5 24.2 22.1 26.2 26.7 3.6

Types.—Holotype: 117705a; figured paratypes: 117705b-e,g,h, unfigured

paratype: 117705f.
Horizon and locality —Ridley formation in Tennessee: In the lower third of

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 931

the formation in Marshall Knobs, 5 miles south of Murfreesboro, Murfreesboro
(15’) Quadrangle.

Discussion.—This species is characterized by moderate convexity and con-
cavity, thin body cavity, long interarea, well-rounded muscle area and fine, well-
differentiated costellae. It differs from S. medialis in the finer ornamentation
and more convex valves. It differs from S. grandimusculosa in the form and
less thickening of the muscle area, the more rectangular cardinal extremities,
differentiated ornamentation, and greater convexity. Strophomena musculosa
from the Decorah shale is more convex and has a wider muscle field in the pedicle
valve. The form and outline of S. costellata are similar, but the ornamentation
of that species consists of costellae less differentiated in size than in the Ridley
species.

STROPHOMENA BASILICOIDEA Cooper, new species
Plate 256, A, figures 1-5

Shell large, subrectangular in outline; hinge forming the greatest width; sides
nearly straight but indented gently anterior to the cardinal extremities. Anterior
margin broadly rounded. Costellae rounded, subequal, somewhat distant and
alternating in size, about 13 to I5 in 5 mm. at the front margin.

Pedicle valve moderately concave in lateral profile; maximum concavity in the
median third; umbo narrowly convex and with a short fold; umbo-lateral areas
gently concave; median third deeply concave but anterior third more gently
concave; interarea fairly long; pseudodeltidium narrowly convex, subcarinate.

Brachial valve evenly and strongly convex in lateral profile; broadly and mod-
erately convex in anterior profile; maximum convexity at about the middle;
posterior third somewhat flattened. Umbo marked by a short, narrow, shallow
sulcus. Median region swollen; anterior slope convex, moderately long and
steep ; lateral slopes moderately long and steep. Interior with delicate cardinalia.

Measurements in mm.—Holotype, length, 25.6, brachial length 23.9, midwidth
31.0, hinge width ?, thickness 3.8.

Type.—Holotype: 117706.

Horizon and locality—Peery formation in Virginia: On U. S. Highway 109,
400 feet west of the junction with Virginia Highway 650, Wittens Mills, Burkes
Garden (15’) Quadrangle.

Discussion.—This species is somewhat like S. basilica but differs in more
closely crowded, stronger costellae and in having a more uniformly inflated
brachial valve and a somewhat more concave pedicle valve.

STROPHOMENA BELLILINEATA Cooper, new species
Plate 262, A, figures 1-7

Shell large, slightly wider than long ; subquadrate in outline ; cardinal extremi-
ties slightly alate; sides nearly straight except for a gentle indentation just an-
terior to the cardinal extremities; anterior margin broadly rounded. Surface
beautifully sculptured and consisting of strong costellae setting off groups of
10 to 12 finer ones; 4 of the stronger costellae appear in a space of 10 mm. at
the anterior margin of a specimen 26 mm. long.

932 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve very gently concave in lateral profile, with the maximum con-
cavity near the valve middle; umbo narrowly and gently swollen to form a dis-
tinct but low fold extending anteriorly for a distance of about 8 mm. Median
region very gently concave; lateral and anterior regions gently and broadly bent
toward the pedicle valve. Interarea short, pseudodeltidium moderately convex;
interior with elongate to subcircular muscle field ; rim surrounding muscles mod-
erately thickened. Old specimens with a moderately thick subperipheral rim.

Brachial valve fairly evenly but gently convex in lateral profile; anterior pro-
file broadly convex ; umbo concave, the concavity continued anteriorly as a short,
narrow sulcus for about 8 mm. Median region gently swollen; lateral areas with
long and gentle slopes. Cardinalia delicate for such a large shell; cardinal process
small; median ridge low and short; sockets formed by narrow cuplike plates.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype (pedicle valve) ............ 33.5 ? 43.3 51.6? ?
Paratype (brachial valve 117707b).... ? 27.0 35.7 389.2 cw Pawe
- (ee ft PARSE Vs stirs ? 35.0 46.8 46.8 ?

Types.—Holotype: 1177074; figured paratypes: 117707b,c, 123283; unfigured
paratypes: 117707d-f.

Horizon and locality—Oranda formation in Broadway (15’) Quadrangle in
Virginia: 0.6 mile west of Linville Station; on Virginia Highway 777 just west
of its junction with Highway 617, 4 mile north of Green Mount Church.

Martinsburg formation (part with Brongniartella=Salona) in Virginia: On
Virginia Highway 617=910, 0.15 mile north of Green Mount Church, Broadway
(15’) Quadrangle.

Discussion—This species is characterized by its large size and strongly differ-
entiated ornamentation. It has about the size of large specimens of S. auburnen-
sis but is readily distinguished from that species by the concavity of the pedicle
valve and the low convexity of the brachial valve.

STROPHOMENA BILLINGSI Winchell and Schuchert

Strophomena recta Bitttncs (not Conrad), Geol. Surv. Canada, Paleozoic fossils, vol. 1,
p. 130, fig. 108 (adv. sheets, 1862), 1865.

S. billingsi WINCHELL and ScHuCHERT, Geol. Minnesota, vol. 3, fig. 32, 1895.—WHILSON,
Geol. Surv. Canada, Bull. 8, p. ror, pl. 11, figs. 14a, b, 1946.

The type specimen is lost.
Horizon and locality—Leray (Chaumont)—Rockland in Ontario, Canada.

STROPHOMENA CANADENSIS Wilson
Plate 248, A, figure 1
Strophomena canadensis Witson, Geol. Surv. Canada, Bull. 33, p. 50, pl. 3, fig. 7, 1921.
Type.—Holotype: G.S.C. 6220.

Horizon and locality—Pamelia formation, 22 miles west of Ottawa, Ontario,
at MacLaren Landing.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 933

STROPHOMENA CONRADI Hall and Clarke

Strophomena conradi HAtt and CrarKe, Pal. New York, vol. 8, pt. 1, p. 344, pl. 9, A, fig. 3,
1892.

Horizon and locality.—Jacksonburg formation in New Jersey: At Jackson-
burg.
STROPHOMENA COSTELLATA Cooper, new species
Plate 255, A, figures I-19

Shell of about average size for the genus, wider than long; hinge forming
widest part; cardinal extremities subalate, deflected toward the brachial valve.
Lateral margins nearly straight or slightly oblique ; front margin broadly rounded.
Surface marked by fine costellae which are of nearly equal size at the posterior,
but between each pair of the primary costellae another finer one is intercalated
for about 4 generations. Costellae increasing in size anteriorly, the primary set
maintaining its advantage and appearing as the larger of the costellae at the front
margin and the other costellae being nearly equal in size. Costellae along the front
margin with less difference in size than the posterior and midregions. At front
margin of a specimen 20 mm. long 15 costellae of nearly equal size occupy a
space of 5 mm.

Pedicle valve with but a slight swelling in the umbonal region, nearly flat at
about the middle where the valve is geniculated in the direction of the pedicle
valve. Cardinal extremities deflected toward the brachial valve more or less
strongly. Median region gently concave and this concavity is extended to the
region of the cardinal extremities where the valve is slightly swollen. Interarea
strongly apsacline, moderately long; delthyrium narrow, pseudodeltidium only
moderately convex. Foramen minute.

Brachial valve moderately convex in lateral profile with the umbonal region
flattened ; high point of convexity at about the middle. Cardinal extremities set
off by moderately deep grooves. Lateral and anterior slopes moderate. Umbonal
region marked by a shallow sulcus visible for 5 to 8 mm. after which it fades into
the general surface. Portions of valve bounding sulcus somewhat flattened.

Interior of pedicle valve: Teeth strong, moderately long ; muscle area varying
from subcircular to oval and in general having a length slightly greater than the
width. Muscle field surrounded laterally by low ridge. Diductor-adjustor im-
pressions subflabellate, separated by a low ridge. Adductor impressions located
slightly posterior to the middle of the muscle field, slightly elevated on a low
ridge. Subperipheral rim low, not greatly thickened.

Interior of brachial valve with short but slender brachiophores almost com-
pletely buried in secondary shell substance that forms the sockets. Median ridge
low, extending to about one-third the distance to the front margin. Lobes of
cardinal process small.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FT OIOE YEU 5 iys\ clays ale isic.c osaieie re e\s 22.3 21.1 27.4 30.1 4.5
Paratype (117714b).......... 21.4 20.2 25.1 26.7 4.0

CUZ ZEAE) sieite testers 17.1 15.9 20.8 22.8 2.8

934 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types—Holotype: 117714a; figured paratypes: 117708, 117712, 117713,
117714b-d, 123278; unfigured paratypes: 117709, 117710a-c, 117711a,b.

Horizon and locahty—Bromide formation (Pooleville member-O-roplecia
gouldi zone and 20 feet above O. gouldi zone) in Carter County, Oklahoma: At
Rock Crossing of Hickory Creek, about center sec. 35, T. 5 S., R. 1 E., Criner
Hills; NW34 sec. 26, T. 5 S., R. 1 E., Criner Hills.

Discussion.—This species is characterized by the general uniformity in size of
the costellae, the elongate muscle area, the flat umbonal region, and the short
median sulcus of the brachial valve.

This species does not resemble any known Strophomena from the Appa-
lachians but has its nearest relative in S. inconsueta C. L. Fenton. It is a wider
shell relatively than S. inconsueta and differs further in the possession of a
more elongate muscle area.

STROPHOMENA CRINERENSIS Cooper, new species
Plate 173, E, figures 25-30; plate 260, B, figures 11-25

Shell small for the genus, outline varying from semicircular to semielliptical.
Hinge generally forming the widest part, cardinal extremities acutely angular,
tending to alate. Surface marked by costellae of unequal size, the larger costellae
separated by 3 or 4 much finer ones. All costellae crossed by prominent fila that
give a cancellated appearance to the surface. At the front margin very fine cos-
tellae have increased sufficiently in size to reduce the inequality of the costellae.

Pedicle valve gently to moderately concave with the maximum concavity lo-
cated at about the center. Umbonal region slightly and narrowly swollen; pos-
terior half gently concave to nearly flat. Cardinal extremities flattened to slightly
concave and deflected toward the brachial valve, a slight oblique fold forming
the divide between the deflected cardinal extremity and the concave portions.
Anterior geniculation not great. Interarea strongly apsacline; moderately long.
Pseudodeltidium narrow and strongly arched. Foramen minute.

Brachial valve moderately to strongly convex in lateral profile, strongly convex
in anterior profile. Greatest convexity of lateral profile at the middle or slightly
anterior to the middle. Umbonal region gently concave, nearly flat to moderately
deeply sulcate. Sulcus extending for about one-third the length. Oblique sulci
just anterior to cardinal extremities deep. Lateral and anterior slopes moderately
steep.

Interior: Muscle area subelliptical, slightly wider than long, its posterior half
surrounded by delicate extensions from the teeth. Median ridge low, scarcely
extending anterior to the front margin of the muscle area. Subperipheral rim
corrugated, not greatly thickened. Interior of brachial valve with cardinal process
well elevated, the brachiophores and their supporting tissue delicate. Muscula-
ture unknown.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 935

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PIO NEV DG. sn ieissicvana siciaborre svaching 14.6 14.6 17.8 20.7 23
Paratype s( 2177102). «jos 05 0m. 95 12.3 12.0 15.6 ? 4.0
" CEL77I7O) 3c forts ote 11.4 Tr2 16.6 18.0 2.5
ss CPEFIIFA) Pere eee ts 12.8 12.5 18.2 19.8 ? 4.4
i GI FENG. SE LR 15.4 15.3 an2 24.0 5.0

Types.—Holotype: 117718; figured paratypes: 117715, 117716a, 117717a-c,
117719a,c; unfigured paratypes: 117716b, 117717d,e, 117719b.

Horizon and locality—Bromide formation (Pooleville member-O-xoplecia
gouldi zone) in Oklahoma: At Rock Crossing of Hickory Creek, about center
sec. 35, T. 5 S., R. 1 E., Carter County; Pooleville member, basal cobbly beds,
Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray County; just west of road on
Russell Ranch, SE# sec. 3, T. 2 S., R. 3 E., Murray County.

Discussion.—This species is characterized by its small size, short and wide
pedicle muscle area, the cancellated pattern on the outside of the valves, and its
generally great width. Strophomena trentonensis Winchell and Schuchert is
the one described species most suggestive of S. crinerensis, but it differs in its
more nearly quadrate form, nearly rectangular cardinal extremities, and gen-
erally larger size.

STROPHOMENA DELICATULA Fenton

Strophomena delicatula FENton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 155, pl. 9,
figs. 4-6, 1928.

Types—Holotype: Walker Mus. 25537; paratype: Walker Mus. 33400;
figured specimen: Walker Mus. 25538.

Horizon and locality—Barnhart formation in Missouri: 24 miles west of
Ste. Genevieve, Weingarten (15’) Quadrangle.

STROPHOMENA DIGNATA Fenton

Strophomena dignata FENton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 151, pl. 10, figs. 3-5,
1928,
Types.—Holotype: Walker Mus. 25532; paratypes: Walker Mus. 25533,
25535-
Horizon and locality.—Barnhart formation in Missouri: 24 miles west of
Ste. Genevieve, Weingarten (15’) Quadrangle.

STROPHOMENA EXIGUA Fenton
Strophomena exigua Fenton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 152, pl. 10, fig. 6,
1928.

Type.—Holotype: Walker Mus. 25956.
Horizon and locality—Upper part of Plattin group (Macy formation) in
Missouri: South Beckett Hill, Weingarten (15’) Quadrangle.

936 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

STROPHOMENA FASCICULATA Cooper, new species
Plate 256, B, figures 6, 7

Shell small, attaining a length of about 0.6 inch; subquadrate in outline ; hinge
straight, not equal to the greatest shell width which is at about the middle; sides
gently rounded ; anterior margin broadly rounded ; costellae consisting of 2 sizes,
a large and prominent set marking off fascicles of finer ones; 15 costellae in
5 mm. at the anterior margin, including 3 of the larger costellae.

Pedicle valve gently convex in lateral profile and with the maximum con-
vexity in the posterior half; anterior half somewhat flattened; anterior profile
nearly flat to very gently convex; umbonal region narrowly convex, the con-
vexity continued anteriorly as a low fold beyond the middle; region just posterior
to the middle gently swollen; flanks sloping gently from median region to the
margins. Pseudodeltidium large, subcarinate.

Brachial valve gently convex with the maximum convexity somewhat anterior
to the middle; posterior somewhat flattened; anterior profile broadly and gently
convex; umbo marked by a shallow sulcus that extends to about the middle to
merge with the slightly swollen anterior two-thirds; flanks with gentle lateral
slopes.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype Ve nde liiteds se eies bas 14.8 13.0 13.3 14.0 ?
Paratype (117754b).......... 10.4 9.6 13.1 10.2 2.2

Types.—Holotype: 117754a; figured paratype: 117754b; unfigured paratypes:
117754c-f.

Horizon and locality—Peery formation in Tennessee: 7 miles southwest of
Clinton, Clinton (T.V.A. 137-SW) Quadrangle.

Discussion.—This species is strongly costellate, and the costellae are strongly
fasciculated. It suggests Pionomena but differs from P. neumani in having a
less convex brachial valve, not so strong a development of the umbonal and
median sulcus, and stronger costellae. It is one of the most strongly fasciculate
species of Strophomena.

STROPHOMENA FILITEXTA (Hall)
Leptaena filitexta Hat, Pal. New York, vol. 1, p. 111, pl. 31B, fig. 3, 1847.
Strophomena filitexta (Hall) Fenton, Amer. Midland Nat., vol. 11, No. 9, pp. 500-503, pl. 38,
figs. I-5, 1920.

Fenton restudied the types of this species which has been widely misidentified
in Middle Ordovician rocks. He indicates that the only species similar to S. fili-
texta are S. auburnensis and S. plattinensis, but they are distinct. He also states
that the cotypes belong to the “typical black Trenton limestone.” The specimen
(pl. 38, fig. 1) which Fenton says is most clearly depicted by the original descrip-
tion is a large one having the width about 14 times greater than the length. The
writer has seen none like this in the collections of Middle Ordovician fossils

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 937

studied, but a specimen in the National Collection from the Hull at Kirkfield,
Ontario, is similar to the illustrated specimen.

STROPHOMENA FILITEXTA OBESA Wilson

Strophomena filitexta obesa Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 133,
pl. 1, figs. 20-21, 1945; Geol. Surv. Canada, Bull. 8, p. 103, pl. 9, figs. 17a, b, 18, 1046.

Types.—Holotype: G.S.C. 7651; paratype: G.S.C. 7570.
Horizon and locality—Leray = Rockland formation, in Ontario, Canada: Pa-
quette Rapids, Ottawa River; southeast of Cumberland.

STROPHOMENA GRANDIMUSCULOSA Cooper, new species
Plate 256, C, figures 8-17

Shell of about medium size for the genus, wider than long and with the hinge
forming the widest part; well-preserved specimens auriculate; sides somewhat
oblique and indented just anterior to the cardinal extremities ; anterior margin
gently rounded. Costellae variable in size, fine and crowded, about 17 to 20 in
5 mm. at the anterior margin of an adult. Entire surface covered by fine con-
centric fila.

Pedicle valve moderately concave in lateral profile and with the maximum
concavity at about the middle or slightly anterior to it. Umbo narrowly con-
vex for a short distance only ; median region concave; posterolateral extremities
flattened. Interior with narrow, thin teeth and dental ridges ; muscle area large,
usually rhomboidal in outline, the anterior end reaching the middle of the valve
or extending slightly anterior to it. Median ridge stout. Anterior ends of diduc-
tor scars usually elongate and making the anterior angle of the rhomb. Inter-
area moderately long, strongly apsacline ; pseudodeltidium subcarinate. Foramen
minute. Subperipheral rim moderately strongly developed.

Brachial valve moderately and fairly evenly convex in lateral profile; broadly
and evenly convex in anterior profile; maximum convexity at about the middle
or just anterior to it. Umbo forming a small, shallow concavity ; median region
swollen and with steep anterolateral and anterior slopes. Posterolateral slopes
less steep than the others; cardinal extremities set out by a broad, oblique
groove. Interior with small cardinalia, a short and low median ridge; adductor
scars striated. Subperipheral rim moderately developed.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Holotype Heres Ppeisc hee J 21st 19.1 25.3 20.2 3.5
Paratype (117721D) 2. oss. oe 23.2 ? 30.2 36.8 ?
es (LIZ 7BAD OPA 21.4 ? 27.1 32.8 ? ?
s (ETZ72AD i sheers anche a ? 24.5 35.3 39.8 ? ?
(LDF 22 Nai token sien 21.8 19.5 25.2 26.7 4.2

Types—Holotype: 1177214; figured paratypes: 117720a, 11772I1b, 117722,
117724a,b; unfigured paratypes: 117720b, 11772Ic, 117723, 117724c.
Horizon and locality—Lebanon formation (Doleroides zone) in Rutherford

938 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

County, Tenn.: On U. S. Highway 41, $ mile southeast of Knox Branch, about
9 miles southeast of Murfreesboro; on U. S. Highway 41, 14 miles northwest of
Mount Olivet, 10 miles southeast of Murfreesboro; on U. S. Highway 70S,
0.4 mile southeast of Readyville; on U. S. Highway 241, 14 miles (map measure)
southwest of Christiana; cut on U. S. Highway 41, 14 miles north of road to
Big Springs about 1 mile southwest of Mount Carmel Church; on U. S. High-
way 70S, 1.65 miles west of Cripple Creek, 14 miles west of Kittrell. On Ten-
nessee Highway 16, 5.1 miles north-northwest of Shelbyville, Bedford County ;
Lewisburg ; east end of the bridge over Round Lick Creek, on U. S. Highway
70N, at Rome, Smith County; near Lesters, south of Aspen Hill, Giles County ;
Columbia, Maury County; Rutherford Creek, 4 miles north of Columbia, Maury
County.

Dryden formation in Tennessee: 30 feet above the marble on the road along
Little Sycamore Creek, 4 mile northeast of the west edge of the Howard Quar-
ter (T.V.A. 162-NW) Quadrangle; Tennessee Highway 53 at Nicely and Pal-
mer’s store, 4 mile east of Kate, Maynardville (30’) Quadrangle.

Ooltewah formation in Tennessee: Northeast of Snow Hill Post Office, Snow
Hill (T.V.A. 112-NW) Quadrangle.

Discussion.—This species is characterized by its rectangular outline, prominent
ears, fine costellae, and large, thickened muscle region. It is most like S. medialis
which also has prominent ears and a fairly wide rectangular outline. Stropho-
mena medialis is, however, much more strongly costellate than S. grandimuscu-
losa, and the muscle area is more rounded than in the Lebanon species.

STROPHOMENA GRANDIS (Okulitch)
Rafinesquina grandis Oxu.itcH, Canadian Field-Nat., vol. 49, No. 6, p. 98, pl. 1, fig. 2, 1935.
Strophomena grandis (Okulitch) Satmon, Journ. Paleont., vol. 16, No. 5, p. 598, pl. 87,
figs. 29, 30, 1942.
Type.—Holotype: Peter Redpath Mus., McGill Univ., Montreal.
Horizon and locality —Lowville formation in Quebec: At Pointe Claire.
Leray =Chaumont formation in Quebec: At St. Vincent de Paul.

STROPHOMENA INCONSUETA Fenton

Strophomena inconsueta Fenton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 154, pl. 10,
figs. I, 2, 1928.

Types——Holotype: Walker Mus. 25987; paratype: Walker Mus. 25989.

Horizon and locality—Upper part of Plattin group (Macy formation) in
Missouri: At South Beckett Hill, Weingarten (15’) Quadrangle.

STROPHOMENA INCURVATA (Shepard)

Producta incurvata SHEPARD, Amer. Journ. Sci., vol. 34, p. 144, figs. 1, 2, 1838.—BAssLER,
U. S. Nat. Mus. Bull. 92, p. 1229, 1915 (for complete bibliography to 1915).—FENTON,
Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 146, 1928.

Rafinesquina incurvata (Shepard) Kay, Bull. Geol. Soc. Amer., vol. 40, No. 1, p. 211, 1920.

This species has been widely identified from lower Middle Ordovician rocks.
A variety of species has been erroneously named Strophomena incurvata. Ac-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 939

cording to Kay this species does not belong to the genus Strophomena, and it
occurs in Upper Ordovician rocks. Kay states as follows: “Shepard, in 1838,
described Producta incurvata from near Navarino, at the head of Green Bay,”
Wis. The northern part of the present city of Green Bay was the town of
Navarino in 1838. “Strophomena incurvata (Shepard)” has been commonly
listed in paleontologic synonymy as a Black River or lower Trenton brachiopod.
No Black River or lower Trenton rocks outcrop in the city. A study of the
type locality reveals that a species of Rafinesquina is common in the Cincinnatian
shaly limestones on Ellis Creek, 3 miles east of the city of Green Bay. The
species is of the genus Rafinesquina, not of Strophomena, and it seems identical
with the form illustrated by Shepard as Producta incurvata.

Strophomena incurvata of authors, not of Shepard, a Black River and lower
Trenton form, is thus a misidentification of Rafinesquina incurvata (Shepard),
a Cincinnatian species.

The writer has examined Shepard’s figures of Producta incurvata and inter-
prets them as belonging to Strophomena rather than Rafinesquina. The only
way to settle this question is to examine the specimens, but Fenton (1928,
p-. 147) states that all his efforts to locate them proved futile, and he suggested
abandonment of the species.

Kay’s solution of the problem seems only half right. The writer will concede
the Cincinnatian age of the beds at Green Bay, but the possibility of Shepard’s
actually having had a Strophomena must not be overlooked. The genus occurs
with Rafinesquina in Upper Ordovician rocks and cannot be ignored even though
Rafinesquina is an abundant form at Green Bay. Shepard, in his description,
speaks of the “shallow valve concave, basal margin incurved” which suggests
Strophomena. His figure of the interior shows a short median ridge and the
cardinalia as somewhat excavated, again suggesting Strophomena. Despite the
generic affinities of the species, it probably belongs in the Upper Ordovician and
can be dismissed from further consideration in the Middle Ordovician.

STROPHOMENA INSPECIOSA Willard

Plate 213, F, figures 26-34; plate 213, G, figures 35-38; plate 262, B, figures 8-11;
plate 264, B, figures 16-22

Strophomena inspeciosa WitLarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6,
p. 286, pl. 2, fig. 13, 1928.

As Willard points out, this species is suggestive of Furcitella scofieldi (Win-
chell and Schuchert) but differs markedly in its internal features. S. inspeciosa
does not have the convex pedicle valve, and the brachial valve is still more con-
vex than that of F. scofieldi, The contours of S. inspeciosa are those of the more
familiar Strophomena.

Types.—Figured hypotypes: 117725, 117726, 117727a, 117728a.b, 117729a-e.

Horizon and locality Wardell formation and Wardell part of Dryden forma-
tion in Tennessee: At the bend of the railroad just west of Liberty Hill, Dutch
Valley (T.V.A. 154-SE) Quadrangle; 4 mile north of Emory Road, 2 miles
northeast of Hall Crossroad, Fountain City (T.V.A. 146-SW) Quadrangle;
Hesperorthis zone, and 40 feet below, Evans Ferry section along U. S. High-

940 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

way 25E, 4 mile north of Indian Creek, Howard Quarter (T.V.A. 162-NW)
Quadrangle; west of Lone Mountain, Tazewell (T.V.A. 154-NE) Quadrangle.

Wardell formation in Virginia: On Fugates Hill north of Mendota, Bristol
(30) Quadrangle.

Ridley= Wardell formation in Georgia: On U. S. Highway 27 just north of
its crossing over Chickamauga Creek, Kensington (T.V.A. 206-SE) Quadrangle.

Carters formation (Oxoplecia bed) in Alabama: Quarry 0.3 mile north of
Gate City, Leeds (15’) Quadrangle.

Mahan formation in Tennessee: 2 miles southeast of Snow Hill, Snow Hill
(T.V.A. 112-NE) Quadrangle.

STROPHOMENA MAGNA Wilson

Strophomena magna Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 134, pl. 1,
figs. 13, 14, 1945; Geol. Surv. Canada, Bull. 8, p. 104, pl. 9, figs. 11, 12, 1946.

Type.—Holotype: G.S.C. 7579.
Horizon and locality—Rockland formation in Ontario, Canada: At Stewart
Quarry, Rockland.

STROPHOMENA MEDIALIS Butts
Plate 259, A, figures 1-16
Strophomena medialis Butts, Virginia Geol. Surv. Bull. 52, pl. 87, figs. 1-6, 1942.

Large and thick, wider than long with the hinge forming the widest part;
cardinal extremities alate; front margin broadly rounded; lateral margins usu-
ally oblique. Surface multicostellate with the larger costellae separated by 1 to
4 finer ones. All costellae enlarging anteriorly with the result that difference in
size between primary and subsequent costellae is greatly lessened; 13 to 15
costellae occupy 5 mm. at the front margin of an adult.

Pedicle valve moderately to deeply concave with depressed part of valve oc-
cupying most of the surface. Cardinal extremities strongly deflected toward the
brachial valve ; surface of cardinal extremities flat to moderately concave. Um-
bonal region gently convex with the convexity continued anteriorly as a low
fold for one-third to one-half the length of the valve. Interarea long and promi-
nent, strongly apsacline; pseudodeltidium low, subcarinate.

Brachial valve moderately convex with the greatest convexity located slightly
anterior to the middle. Posterior slope moderately steep, gently convex in pro-
file ; anterior slope somewhat steeper than the posterior one and also gently con-
vex in profile. Median sulcus shallow but prominent, having about the same
relation to the brachial valve that the fold of the pedicle valve has to that valve.
Region about the sulcus gently swollen, with gentle to moderately steep slopes
to the depressions setting off the deflected cardinal extremities, these depressions
varying from gently to deeply concave. Lateral slopes moderately steep. Inter-
area exceedingly short, the palintrope forming a narrow ridge along the line
of valve juncture. Chilidium short and low.

Interior of pedicle valve with a nearly circular to broadly cordate muscle area
having a diameter equal to about one-third the valve length. Median ridge in-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 941

conspicuous, narrow, low, and thin to absent. Delthyrial cavity shallow. Teeth
small; dental ridges flaring, not reaching the middle of the muscle area. Inside
the brachial valve muscle impressions and cardinalia confined to the posterior
third ; cardinal process moderately large.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
ECE ABO. wi5/0 sidnaioieis uae s avelereve.s 26.8 24.3 30.4 33.6 4.4
Paratype (O8201C) wi. .<caes 28.0 26.7 36.6 42.8 3.0
Hypotype (117730b) ......... 26.1 ? 20.6 37.3 ?
a CLI77304a)): bs Eke 25.2 23.7 2777 31.9 4.0

Types.—Lectotype: 98201a; paratypes: 98201b,c; figured hypotypes:
117730a,b, 117732a, 117733a, 117734a, 1177374.

Horizon and locality.—Wardell formation and Wardell part of Dryden forma-
tion in Virginia: 1 mile west of Rye Cove and several other points in the near
vicinity of Rye Cove, Clinchport (T.V.A. 188-NW) Quadrangle; Route 19,
Little Indian Creek, 24 miles west of Paint Lick, Richlands (15’) Quadrangle;
top 40 feet on Virginia Highway 610 at the southwest base of Paint Lick Moun-
tain, Pounding Mill-Richlands (15’) Quadrangles; quarry on Station Creek,
4 mile south of U. S. Highway 58, 2 miles east of Cumberland Gap, Wheeler
(T.V.A. 153-SE) Quadrangle ; Mannville School, Clinchport (T.V.A. 188-NW)
Quadrangle.

Same formations in Tennessee: On the north side of the road 1.1 miles north-
east of Lee Valley, Lee Valley (T.V.A. 171-NW) Quadrangle; along the ridge
just southwest of the old store near Hayes’ house, Evans Ferry section on
U. S. Highway 25E, 4 mile north of Indian Creek, Howard Quarter (T.V.A.
162-NW) Quadrangle; bend of the railroad just west of Liberty Hill, Dutch
Valley (T.V.A. 154-SE) Quadrangle.

Discussion.—This species is abundant in the Wardell formation and is charac-
terized by strong costellae, strong ears on the cardinal extremities, and moderate
convexity. The species differs from S. auburnensis nasuta in having less con-
vexity and different ornamentation. The costellae are stronger than those of
S. costellata and S. basilica.

STROPHOMENA ? MILLIONENSIS AFFINIS Wilson

Strophomena? millionensis affinis Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 30, sec. 4,
p. 135, pl. 1, fig. 5, 1945; Geol. Surv. Canada, Bull. 8, p. 104, pl. 9, fig. 5, 1946.

Type.—Holotype: G.S.C. 7586.
Horizon and locality—Leray (Chaumont)— Rockland beds in Ontario,
Canada: On the Cobden-Eganville road.

STROPHOMENA MINUTA Wilson
Strophomena minuta Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 135, pl. 1,
figs. 1-3, 1945; Geol. Surv. Canada, Bull. 8, p. 105, pl. 9, figs. 1-3, 1946.
Type.—Holotype: G.S.C. 7616.
Horizon and locality—Leray =Chaumont formation in Ontario, Canada: At
Stewart Quarry, Rockland.

942 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

STROPHOMENA MOLLIS Wilson

Strophomena mollis Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 136, pl. 1,
fig. 4, 1945; Geol. Surv. Canada, Bull. 8, p. 105, pl. 9, fig. 4, 1046.

Type.—Holotype: G.S.C. 7588.
Horizon and locality —lLeray =Chaumont formation in Ontario, Canada: At
Lots 3-5, concession III R. F., Gloucester Township.

STROPHOMENA MUSCULOSA Fenton

Strophomena musculosa Fenton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 153, pl. 8, figs. 1-7,
1928.

Types.—Holotype: Walker Mus. 25524; paratypes: Walker Mus. 25527,
33421, 25525.

Horizon and locality—Decorah formation (Ion member) in Minnesota: At
Fountain, Goodhue County.

STROPHOMENA OKLAHOMENSIS Cooper, new species
Plate 260, A, figures I-10

Shell small, wider than long, somewhat rectangular to semielliptical in out-
line. Cardinal extremities varying from an acute angle to a right angle. Lateral
margins variable, slightly oblique to perceptibly convex; anterior margin gently
convex. Surface marked by costellae of unequal size. A single costella inter-
calated between each of the primary costellae; one intercalated between each
primary costella and the secondary one. This method of increase is continued
on the entire surface. Intercalated costellae may grow to equal the primary
costellae in strength. Consequently, the anterior parts of the valve do not show
strong differentiation between the costellae; this is displayed on the posterior
parts in varying degree depending on the individual specimen.

Pedicle valve gently concave in the front half, flattened or concave anterior to
the cardinal extremities depending on age; cardinal extremities moderately de-
flected. Umbonal region narrowly convex, extended forward as a narrow but
low fold nearly to the middle of the valve where the fold disappears in the
general surface. Interarea very strongly apsacline; pseudodeltidium narrow,
strongly arched.

Brachial valve moderately convex with the maximum curvature at about the
middle or slightly posterior to the middle. Umbo sulcate, sulcus narrow and
moderately deep, extending nearly to the middle of the valve. Area surround-
ing the sulcus flattened. Anterior and lateral slopes moderately steep; cardinal
extremities not greatly deflected.

Interior of pedicle valve with a nearly circular muscle field not quite extending
to the middle. Floor of muscle field moderately thickened, and slightly elevated ;
half enclosed by extensions from beneath the teeth. Median ridge low and short,
extending about to the anterior ends of the diductor impressions. Teeth small.
Subperipheral rim varying from obsolete (not developed) to moderately strong.
Portion outside subperipheral rim narrow. Interior of brachial valve unknown.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 943

Measurements in mm.—

Brachial Hinge ;
Length length Width width Thickness
TIGIOL YE... RG: DI. Jat 13.5 13.4. 16.8 ? 2.9
Paratype » (177392) scr «at 20s ? II.0 13.6 14.0 ?
‘e GED77900'),. kes oe we 12.8 ? 16.6 17.3 ?

Types—Holotype: 117738a; figured paratypes: 117739a,b; unfigured para-
types: 117738b, 117739¢c.

Horizon and locality.—Bromide formation (Pooleville member-just above zone
with Multicostella convexa) in Oklahoma: At Rock Crossing of Hickory Creek,
approximately center sec. 35, T. 5 S., R. 1 E., Criner Hills, Carter County;
Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray County.

Discussion.—This species is small in size like S. crinerensis but differs in its
more uniformly square outline, strong median fold and sulcus, less-cancellated
surface ornamentation, less-developed cardinal extremities, and details of the
musculature.

STROPHOMENA OKULITCHI Cooper, new name
Plate 265, B, figures 3, 4

Strophomena corrugata Oxutitcu (not Conrad 1842), Canadian Field-Nat., vol. 49, No. 6,
p. 90, pl. 1, fig. 7, 1935.

This is a small, deeply concave species known only from the pedicle valve.
The species is especially interesting because of the strong, coarse pseudopunctae
arranged in rows as in Rafinesquina.

The new name is proposed to replace Strophomena corrugata Conrad, Journ.
Acad. Nat. Sci. Philadelphia, vol. 8, p. 256, pl. 14, fig. 8, 1842, which preoccupies
the Okulitch name.

Type——Holotype: Peter Redpath Mus., McGill Univ., Montreal (no
number).

Horizon and locality—Leray =Chaumont formation in Canada: At St. Vin-
cent de Paul, Quebec.

STROPHOMENA PLANOBESA Cooper, new species
Plate 261, A, figures 1-13; plate 261, B, figures 14-17

About average size for the genus, wider than long, hinge forming the widest
part; sides straight or slightly oblique, indented anterior to the auriculate cardi-
nal extremities. Anterior margin strongly rounded; costellae variable, alternat-
ing in size, 13 to 17 in 5 mm. at the front margin of a large adult.

Pedicle valve gently concave in lateral profile but with the posterior quarter
slightly convex ; greatest concavity just anterior to the middle; umbo narrowly
swollen to form a short fold; flanks on each side of fold gently concave ; median
half gently concave ; front half and sides deflected toward the pedicle valve. In-
terarea moderately long; pseudodeltidium wide and low, subcarinate.

Brachial valve unevenly convex in lateral profile, with the posterior quarter
flattened but the median region strongly convex; anterior profile narrowly con-

944 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

vex with steep lateral slopes ; umbonal region marked by a shallow and indistinct,
short sulcus; area surrounding sulcus gently convex; median region tumid, with
lateral and anterior slopes moderately long and very steep.

Interior of pedicle valve with thin and delicate dental processes and ridges;
muscle area large, variable in outline from subcircular to oval; lateral margins
of muscle field without elevated rim. Brachial interior with short, stout cardinal
process, moderately long median ridge, and shallow, confined socket cups.

Measurements in mm.—

Brachial Hinge Thick-
Length length §$Midwidth width ness Height
HIGH Pe Fics cccsee cs Fi 18.8 21.0 19.0 ? 5.5
Paratype (117740a).. 21.2 ? 24.0 25.8 ? ?
rs (117740b).. 19.3 ? 20.6 21.4 ? e
(117740c).. 20.2 ? 21.6 21.1-+ ? ?
¥e (397 7AON) i005 Wik 2a7 30.6 23.9 ? 7
(3232700) s. ? 20.8 23.2 21.0 ? 5.0
cs (2232700) 25, nt 19.0 24.4 21.9 ? 5.5

Types——Holotype: 117740f; figured paratypes: 117740¢,¢,g, 117741a-d,
123279a-c ; unfigured paratypes: 117740a,b,d, 117741e,f.

Horizon and locality—Ridley or Murfreesboro formation (with Ancistro-
rhyncha) in Tennessee: On Crystal Creek, 5 miles south of Pikesville, Sequat-
chie Valley, Pikeville Special (15’) Quadrangle.

Murfreesboro formation in Tennessee: Near the top of the formation at the
crossing of U. S. Highway 70 and Stone River 14 miles northwest of Murfrees-
boro on the new armory grounds, Murfreesboro (15’) Quadrangle.

Discussion.—This species is characterized by a gently concave pedicle valve
but a fairly strongly convex brachial valve. It is also characterized by a
squarish outline with small ears. The species is differently shaped and more
evenly costellate than S. basilica. It differs in outline and ornamentation from
S. grandimusculosa and S. medialis. No other species of the size of this one has
the same convexity and outline.

STROPHOMENA PLANUMBONA (Hall)

Plate 265, A, figures I, 2

This interior of the brachial valve is introduced for comparison with the
brachial valve of Furcitella and other species referred to Strophomena.

Figured specimen.—117945.

Horizon and locality—Liberty formation in Ohio: On Dodges Creek 13 miles
northwest of Oxford.

STROPHOMENA PLANUMBONA PRAECIPITA Wilson
Strophomena planumbona praecipita Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4,
p. 136, pl. 1, figs. 9, 10, 1945; Geol. Surv. Canada, Bull. 8, p. 106, pl. 9, figs. 9a, b, 1946.

Type.—Holotype: G.S.C. 1156a.
Horizon and locality—Leray=Chaumont formation in Ontario, Canada:
Above Mechanicsville, Ottawa.

BART yo CHAZYAN AND RELATED BRACHIOPODS—COOPER 945

STROPHOMENA PLATTINENSIS Fenton

Strophomena plattinensis Fenton, Amer. Midland Nat., vol. 11, Nos. 3, 4, p. 149, pl. Io,
figs. 7-9, 1928.

Type—Holotype: Walker Mus. 25988; paratypes: Walker Mus. 25501,
25983.

Horizon and locality—Platteville formation in Wisconsin: At Mineral Point,
Mineral Point (30’) Quadrangle.

Plattin group (Macy formation) in Missouri: South Beckett Hill, Wein-
garten (15’) Quadrangle.

STROPHOMENA PLATTINENSIS CRASSA Raasch

Strophomena plattinensis crassa Raasch, in SHrock and RaascH, Amer. Midland Nat.,
vol. 18, No. 4, pp. 549, 592, pl. 4, figs. 3, 7, 1937.

Horizon and locality.—Platteville formation (blue beds) in Wisconsin: At
Beloit, Rock County; 2 miles west of Klevenville, Dane County.

STROPHOMENA PLATYUMBONA Cooper, new species
Plate 254, C, figures 7-10

Shell moderately large for the genus, wider than long and with the greatest
width at the hinge. Cardinal extremities acute and subauriculate. Sides gently
rounded and slightly oblique toward the middle; anterior margin somewhat
narrowly rounded. Surface finely costellate, costellae subequal in size and
numbering 3 to the millimeter at the front margin.

Pedicle valve fairly evenly concave in lateral profile and with the deepest part
located just anterior to the middle; umbo only slightly swollen and the swelling
continued anteriorly for a short distance only; median region flattened; sides
and anterior abruptly bent in the direction of the pedicle valve to form a deeply
concave region just anterior to the middle; cardinal extremities flattened and
deflected in the direction of the brachial valve. Interior with narrowly elongated
muscle field and with the diductor scars considerably elongated at their antero-
median extremities.

Brachial valve with the posterior third gently concave, the median third mod-
erately swollen and the anterior third gently convex in lateral profile. Anterior
profile moderately and broadly convex. Lateral slopes moderately long, mod-
erately steep; anterior slope somewhat steeper than the lateral ones. Interior
with short median ridge, short brachiophores, and small cardinal process.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness Height
Holotype” (424.4... dv2pi0 y 30.0 35.9 ? ?
Paratype (117743b).. 29.8 G 33.5 35.3 ? ?
= (117743e).. 20.2 28.0 32.4 Fi 4.9 7.0

Types.—Holotype: 117743a; figured paratypes: 117743b-d; measured para-
type 117743¢.

946 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality.—Carters formation (O-xoplecia bed) in Alabama: In
the quarry 0.3 mile north of Gate City, Leeds (15’) Quadrangle.

Discussion—This species is characterized by having a fairly large size and
somewhat nasute front. It differs from S. basilica in having costellae of fairly
even size and a more nasute front. It is unlike S. medialis in ornamentation and
outline. It is also unlike S. grandimusculosa in being elongate rather than trans-
verse and in having a less square and thickened muscle area in the pedicle valve.
It has the form of S. auburnensis nasuta but is differently ornamented and has
a smaller muscle area in the pedicle valve. It suggests S. dignata Fenton, but
that species is larger, has a larger pedicle muscle scar and more differentiated
ornamentation.

STROPHOMENA ROTUNDA Wilson

Strophomena rotunda Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 137, pl. I,
fig. 8, 1945; Geol. Surv. Canada, Bull. 8, p. 106, pl. 9, fig. 8, 1946.

Type.—Holotype: G.S.C. 7589.
Horizon and locality.—Leray =Chaumont— Rockland beds in Ontario, Can-
ada: On road east from Skead, east of Ottawa.

STROPHOMENA ? SCULPTURATA Bassler
Plate 222, C, figure 4

Strophomena sculpturata BASSLER, Cambrian and Ordovician: Geol. Surv. Maryland, p. 250,
pl. 40, fig. 1, 1919.

This is one of a number of species that have been described in North America
and abroad which are characterized by the stropomenoid form but, in addition
to the normal costellae, are more or less strongly wrinkled. The wrinkling is
not like that of Leptaena but is more suggestive of Bellimurina. Little is known
of the interior details of these species. The type of wrinkling displayed appears
in many stocks that are demonstrably different, and this makes the wrinkling in
itself a dubious character for generic differentiation. The same type of orna-
mentation also occurs in a rafinesquinoid stock.

Types.—Holotype : 66165 ; paratypes: 66165a-c.

Horizon and locality—Martinsburg formation (Simuites zone) in Pennsyl-
vania: I mile south of St. Thomas, Mercersburg (15’) Quadrangle.

STROPHOMENA SEPTATA Winchell and Schuchert

Strophomena septata WINCHELL and SCHUCHERT, Amer. Geol., vol. 9, p. 285, 1892; Geol.
Minnesota, vol. 3, pt. 1, p. 390, pl. 30, figs. 1-3, 1895.

Horizon and locality—Decorah formation (Ion member) in Minnesota.
STROPHOMENA VENUSTULA Wilson

Strophomena venustula Witson, Trans. Roy. Soc. Canada, ser. 3, vol. 39, sec. 4, p. 138, pl. 1,
figs. 6, 7, 1945; Geol. Surv. Canada, Bull. 8, p. 107, pl. 9, figs. 6, 7, 1946.

Types.—Holotype: G.S.C. 7591; paratype: G.S.C. 7599.
Horizon and locality—Leray =Chaumont— Rockland beds in Quebec, Can-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 947

ada: On Lot 24, concession VII, Allumette. In Ontario: At Mechanicsville,
Ottawa.
STROPHOMENA sp. 1

Plate 257, C, figures 13-15

This species is known only from adult brachial valves and fragments of the
pedicle valve. The brachial valve is strongly convex in lateral profile and has
the maximum convexity located at about the middle. The anterior profile is
broadly and strongly convex. The umbonal region is gently convex and forms
a steep slope—steeper than the anterior one. The median region is strongly
inflated. This Nevada species is most like S. planobesa, new species, in its pro-
files and general form, but it is more convex and has a somewhat different outline.

Figured specimen.—117742Aa.

Horizon and locality.—Just beneath the Eureka sandstone in Nevada: In the
Antelope Range on the west side about 3 miles south of Ninemile Canyon,
Roberts Mountains, (1°) Quadrangle.

Suborder DICTYONELLOIDEA Cooper, new suborder

Shells having a smooth umbonal attachment for the pedicle.

Family EICHWALDIIDAE Schuchert, 1893

Usually triangular shells with narrow lateral grooves in the brachial valve for
articulation.
Genus EICHWALDIA Billings, 1858

Eichwaldia Bitirncs, Geol. Surv. Canada, Rep. on Progress for 1857, p. 190, 1858.

EICHWALDIA SUBTRIGONALIS Billings
Plate 163, A, figures 1-6

Eichwaldia subtrigonalis Bittrncs, Geol. Surv. Canada, Rep. on Progress for 1857, p. 192,
fig. 24, 1858; Canadian Nat. Geol., vol. 3, p. 443, fig. 24, 1858; Geol. Canada, p. 142,
fig. 76, 1863.—Hatt and CLarxe, Pal. New York, vol. 8, pt. 2, p. 310, figs. 241, 242,
pl. 83, figs. 1-4, 1893—Wzutson, Geol. Surv. Canada, Bull. 8, p. 120, pl. 8, figs. 6-9, 1946.

Types——Holotype: G.S.C. 1145a; paratypes: G.S.C. 1145b-g; hypotype:
G.S.C. 6418; figured hypotypes: U.S.N.M. 92360d,f.

Horizon and locality—Rockland formation in Canada: Paquette Rapids,
Ottawa River, Ontario; Allumette Island, Ottawa River, Quebec.

Suborder DALMANELLOIDEA Moore, 1952
Punctate brachiopods with orthoid-type cardinalia.
Superfamily DALMANELLACEA Schuchert and Cooper, 1931

Family DALMANELLIDAE Schuchert, 1929

(= WarTTSELLIDAE Schuchert and Cooper, 1931)

Dalmanellacea with subcircular or shield-shaped shells having a cordate pedicle
muscle field and fulcral plates defining the sockets.

948 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genus DALMANELLA Hall and Clarke, 1892

Dalmanella Haut and CrarkeE, Pal. New York, vol. 8, pt. 1, pp. 205, 223, 1892.—Or1xk, Acta et
Comment. Univ. Tartu, ser. A, vol. 25, No. 1, p. 14, 1933.

Wattsella BANcrort, Mem. Manchester Lit. Phil. Soc., vol. 72, p. 55, 1928—ScHUCHERT and
Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 125, 1932.

DALMANELLA COSTELLATA Cooper, new species
Plate 158, E, figures 17-33

Shell small for the genus, oval in outline; sides and anterior margin strongly
rounded; anterior commissure gently sulcate; valves unequally convex, the
brachial valve having the lesser convexity. Costellae numbering 3 to the milli-
meter at the anterior margin; spaces between costellae marked by strong, closely
spaced fila.

Pedicle valve strongly convex in lateral profile with the maximum convexity
at the middle; anterior profile strongly convex. Beak bluntly rounded; umbo
narrowly swollen and merging into the strongly swollen median region ; anterior
and lateral slopes steep. Interarea long, curved, gently apsacline.

Brachial valve gently convex in lateral profile; anterior profile gently con-
cave, the median region a shallow concavity bounded by flattened flanks. Umbo
sulcate, the sulcus widening anteriorly to the front margin where it is broad
and shallow. Flanks gently swollen; lateral slopes short and gentle.

Pedicle interior with short, stout dental plates, subcordate muscle field, stout
teeth, and thick vascula media. Brachial valve with long, narrow, and deep
notothyrial cavity ; fulcral plates stout, obsolete in old specimens. Cardinal proc-
ess small. Anterior adductor pair iarger than the posterior pair.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hleldtypes Ge) u22 is ROMs 8.7 7.9 8.8 5.6 4.5
Paratype (117359a)..... 7.5 6.8 ay 4.0 4.3
“ GiT7356b) wh ..2 7.8 6.8 7.8 3.6 4.0
f° (@17350c).o. 18 7.2 6.6 aE 4.1 3.9
t (1173590d)..... 8.8 7.0 8.8 6.0 4.6

Types.—Holotype: 117359f; figured paratypes: 117359a,e, 117360b,c; un-
figured paratypes: 117359b-d, 117360a,d.

Horizon and locality—Oranda formation in Virginia: Just west of the junc-
tion of Virginia County Highways 617=910, and 777, 4 mile north of Green

“Mount Church, Broadway (15’) Quadrangle: 0.6 mile northwest of Linville
Station, Broadway (15’) Quadrangle; on U. S. Highway 11, 1 mile southwest
of Strasburg, Strasburg (15’) Quadrangle.

Discussion.—This species is characterized by its narrow hinge, elongate-oval
form, fine costellae, and gentle sulcus. It differs from D. sculpta in its oval form
and finer costellae. The species is abundant in some exposures of the Oranda
formation where it occurs as impressions of the interior and exterior. The in-
terior impressions show the great variation of the brachial structures which
range from typical Dalmanella, with well-marked brachiophore supports at-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 949

tached to the median ridge, to forms in which the fulcral plates are nearly or
quite obsolete.

DALMANELLA CRASSICGSTELLATA Cooper, new species
Plate 121, B, figures 2-8; plate 146, C, figures 24-30

Shell small, rectangular in outline, wider than long; hinge slightly less than
the greatest width which is at the middle; sides gently rounded; anterior margin
broadly rounded; anterior commissure somewhat narrowly sulcate; costellae
strong, 2 to the millimeter at the front margin.

Pedicle and brachial valves about equal in depth; pedicle valve with gentle
convexity in lateral profile; narrowly convex in anterior profile and with long,
steep lateral slopes; umbo subcarinate, the carina extending to the front margin
as a strong fold. Flanks bounding fold sloping moderately steeply to the mar-
gins. Beak low, slightly incurved.

Brachial valve with gentle convexity in lateral profile; anterior profile with
narrowly depressed middle bounded by 2 low humps; umbo sulcate, sulcus nar-
row and deep from beak to margin; flanks bounding sulcus moderately swollen ;
lateral slopes long and gentle to the margins. Interior with long brachiphore
plates uniting with the median ridge; cardinal process with long shaft and small
myophore.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
HIGIOtYDE)) Wives. ce ea cats 9.2 8.9 Tit 9.0 3.4
Paratype (117361a).... 6.7 6.2 8.3 7.2 3.6
- (TI7Z60 ees 8.8 7.8 10.1 8.0 3.3
« GrT7SGIC Dh. «05).°0:4 8.7 10.6 0.5 3.4

Types.—Holotype: 117361d; figured paratypes: 117361a,e,f; unfigured para-
types: 117361b,c,g-i.

Horizon and locality—Lower Hermitage formation in Tennessee: Along
Tennessee Highway 53, 0.7 mile south of Woodbury, Woodbury (15’) Quad-
rangle.

Discussion——This species is common in the lower part of the Hermitage
formation in West Tennessee. It can be recognized by its wide hinge, deep
sulcus, and fairly thick contour when compared to Onniella planoconvexa Cooper
with which it occurs. It has about the same size as D. rara but generally is not
as thick as that species, is somewhat more finely costellate, and has a less promi-
nent sulcus than the East Tennessee form. This species is much smaller in size
than D. sulcata and has a much shallower sulcus.

DALMANELLA RARA Cooper, new species

Plate 126,1, figures 46-51; plate 157, B, figure 4; plate 158, A, figures 1-5;
plate 161, B, figures 17-22; plate 162, C, figures 13-18

Shell of about medium size for the genus, subrectangular in outline; wider
than long, with a wide hinge; greatest width at the middle; sides gently rounded ;

950 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

anterior margin strongly rounded; anterior commissure sulcate. Costellae num-
bering 2 (rarely 3) to the millimeter at the front margin.

Pedicle valve gently convex in lateral profile, with the maximum curvature
just posterior to the middle and the front half to third somewhat flattened ; an-
terior profile broadly triangular. Umbo narrowly convex, the convexity con-
tinued to the front margin to form a low fold; flanks bounding fold flat in pro-
file and sloping steeply to the margins. Beak long; interarea long, apsacline.

Brachial valve most convex in the posterior half when seen in lateral profile,
the front half flattened. Anterior profile forming 2 low mounds separated by a
shallow depression. Sulcus deep and narrow, widening and becoming shallower
toward the anterior margin. Flanks bounding sulcus moderately and somewhat
narrowly swollen; lateral slopes low and gently sloping.

Interiors as usual in the genus; the pedicle valve having short, flaring dental
plates and the brachial valve with prominent parallel brachiophore supports.

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
Holotype hic. sraslsns ots 10.2 9.4 11.5 9.1 4.8
Paratype (117362a).... 8.0 he 9.5 8.9 4.8
sf (rrz362b ). 228) 7:8 7.3 9.2 8.3 3.4

Types.—Holotype: 117362c; figured paratypes: 96362e, 117362a,b, 1173632,
d,e,g.

Horizon and locality —Curdsville formation in Tennessee: On Tennessee
Highway 33, 54 miles northeast of Maynardville, Maynardville (T.V.A. 145-SE)
Quadrangle ; $ mile north of Sill (now under Norris Lake), lat. 36°17’31”, long.
83°53'55", White Hollow (T.V.A. 145-SW) Quadrangle.

Same formation in Virginia: At Pennington Gap, Lee County.

Discussion.—This species is characterized by a fairly robust form although it
is not nearly so large a shell as D. sulcata. It has a wide hinge with gently obtuse
cardinal extremities, fairly strong costellae, and a moderately deep sulcus. Dal-
manella rara is most like D. crassicostellata but differs in its larger size, thicker
contour, deeper sulcus and somewhat finer costellae. The species is also identi-
fied on the type slab of Onniella fertilis (Ulrich). On the reverse side of this
slab to that which is figured a number of brachial interiors appear which have
the subparallel brachiophore plates united with the median ridge that so charac-
terizes Dalmanella. The specimens are here referred to D. rara and have the
same association with O. fertilis as occurs at the locality northeast of Maynard-
ville. The same association was found in silicified material etched from Tren-
ton limestone collected 4 mile north of the submerged settlement of Sill in the
White Hollow (T.V.A. 145-SW) Quadrangle, Tenn.

DALMANELLA SCULPTA Cooper, new species
Plate 158, F, figures 34-46

Shell of about medium size for the genus, subcircular in outline; hinge nar-
row; sides and anterior margin strongly rounded; anterior commissure gently

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 95!

sulcate. Costellae strong, narrowly rounded or subangular, numbering about 2
to the millimeter at the anterior margin. Interspaces with strong fila often pro-
ducing a beaded effect.

Pedicle valve moderately strongly convex in lateral profile with the maximum
convexity just posterior to the middle; anterior profile strongly convex and with
steep lateral slopes. Umbo narrowly rounded, the folding continuing to a point
at or just anterior to the middle. Median region swollen; anterior and lateral
slopes convex, steep. Beak incurved; interarea short, curved, apsacline.

Brachial valve evenly and moderately convex in lateral profile; broadly and
gently convex in anterior profile but with the median region gently depressed ;
umbo sulcate, the sulcus increasing in width anteriorly where it is broad and shal-
low ; flanks bounding sulcus gently inflated. Interior of young brachial valves with
convergent and subparallel brachiophore plates but poorly developed fulcral
plates. Cardinal process small, with thin shaft. Adults with thickened and en-
crusted brachiophores and fulcral plates obsolete. Anterior adductor pair much
larger than the posterior pair.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
BIGGER E) os )oss He biais aus 11.0 10.3 11.5 6.4 5.8
Paratype (117364a)... 10.0 9.0 10.0 6.2 4.5
* (117364b) . 3. 7-5 6.8 7.4 4.6 3.7

Types—Holotype: 117364c; figured paratypes: 117364a,d,e; unfigured para-
types: 117364b,f-1.

Horizon and locality—Martinsburg formation (part with Brongniartella=
Salona formation) in Broadway (15’) Quadrangle, Virginia: On Virginia
County Highway 617=910, about 0.15 mile north of Green Mount Church;
0.6 mile northwest of Linville Station.

Discussion.—This species is characterized by its circular outline, small, sub-
erect beak, gentle sulcus, moderately strong costellae with prominent fila that
often produce a beaded effect on the costellae. The species is suggestive of
D. costellata which occurs in the Oranda formation just below the Salona. It
differs, however, in not having the oval form and fine ribbing of the Oranda
species.

This species shows an interesting feature besides the development of the
beaded costellae. In two specimens the myophore has a high-crested median
ridge suggestive of Cristiferina, but the cardinalia are not like those of that
genus. The beak regions of many specimens were cleaned out in an effort to
learn the constancy of this feature, but most of the specimens, after careful
preparation, failed to show the strong myophore crest.

DALMANELLA SULCATA Cooper, new species
Piate 161, A, figures 1-16

Shell of about medium size for the genus, subrectangular in outline; wider
than long; maximum width at or near the middle; hinge narrow, about two-

952 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

thirds the width; sides gently rounded to nearly straight; cardinal extremities
obtuse, narrowly rounded; anterior margin strongly rounded; anterior com-
missure narrowly sulcate. Costellae numbering 2 or 3 to the millimeter at the
front margin.

Pedicle valve deeper than the brachial valve, gently convex in lateral profile
with the maximum convexity at the umbo; anterior profile forming a broad tri-
angle, the median region carinate and the sides sloping moderately. Beak low,
incurved; umbo carinate, the carina continuing from the beak to beyond the
middle and becoming more rounded in the anterior third, thus forming a fold
from beak to margin. Median region inflated. Interarea moderately long, curved,
apsacline.

Brachial valve gently convex in lateral profile and with the anterior third
somewhat flattened ; anterior profile bilobed, with 2 convex lobes with a shallow
depression occupying the middle between them. Umbo deeply sulcate; sulcus
narrow, extending to the anterior margin and becoming wider and shallower in
its passage to the front margin. Flanks bounding sulcus moderately inflated ;
lateral slopes short and gentle.

Pedicle interior with small teeth, flaring dental plates with a thickening an-
terior to them and enclosing the sides of the muscle area ; diductor scars elongate,
separated anteriorly; adductor field narrowly elliptical. Brachial interior with
brachiophores united to median septum; cardinal process with moderately long,
cleft shaft and small myophore.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
RTOS T Sicmiies) SAU Perey 11.4 10.7 13.2 9.9 4.9
Paratype. (117365b) ss. «2 «62% 12.8 12.4 15.7 10.2 5.4
< CT P7SGEE) oA susie oftincs rf fer) II.1 13.9 9.3 5.0

Types.—Holotype: 117365a; figured paratypes: 117365b,e,f,h,i, 123239a; un-
figured paratypes: 117365¢,d,¢.

Horizon and locality—Hermitage formation (base) in Tennessee: On U. S.
Highway 70S-41 near its junction with Spence Lane, 4.2 miles southeast of
Nashville, Hermitage (15’) Quadrangle.

Discussion.—This is a large species characterized by robust form, subrectan-
gular, fine costellae and deep sulcus and corresponding subcarinate fold on the
pedicle valve. It is the largest species of Dalmanella described herein and differs
from all others in this monograph in that respect. It differs from D. crassicos-
tellata also in having finer costellae, deeper sulcus, and stronger fold.

Some of the specimens are characterized by nearly right angled cardinal ex-
tremities, but in others the cardinal extremities are strongly rounded. In other
respects these specimens are like the more typical square-shouldered forms. The
ones with rounded cardinal extremities may ultimately prove to be related to
Onniella rather than Dalmanella, but this could not be demonstrated with the
collections available.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 953

DALMANELLA WINCHELLI Cooper, new name
Plate 158, D, figures 15, 16

Orthis (Dalmanella) hamburgensis ? WINCHELL and ScHUCHERT (not Walcott, 1884), Geol.
Minnesota, vol. 3, pt. 1, p. 440, pl. 33, figs. 14-16, 1895.

This new name is proposed for Dalmanella hamburgensis Winchell and Schu-
chert which is totally unlike Orthis hamburgensis Walcott from the Lower
Ordovician (Goodwin formation) of the Eureka District, Nev. The Nevada
shell is the type species of the genus Nanorthis, whereas the Minnesota shell has
the structure of true Dalmanella.

Figured specimens.—48758a,b.

Horizon and locality—Decorah formation (Guttenberg member-Rhinidictya
bed) in Minnesota: At St. Paul.

Discussion—The National Museum collection contains a few coarsely costel-
late dalmanellids with wide hinge that may ultimately prove to belong to the
genus Dalmanella with nearest relationships to D. winchelli. These occur at
several horizons.

Family ONNIELLIDAE Opik, 1933

Dalmanellacea in which the muscle field of the pedicle valve is bilobed, the
diductor scars not enclosing the adductor impressions. Brachiophores simple
and bladelike, without fulcral plates in the adult.

Genus ONNIELLA Bancroft, 1928

Onniella BANcrort, Mem. Manchester Lit. Phil. Soc., vol. 72, p. 55, 1928; Journ. Paleont.,
vol. 19, No. 3, p. 211, 1945.

ONNIELLA ? AMERICANA Cooper, new species
Plate 37, C, figures 8-14

Shell attaining a width of about 3 inch, wider than long, subrectangular in
outline ; sides broadly rounded; anterior margin nearly straight. Brachial valve
convex ; pedicle valve convex at the rear but moderately concave in the median
region. Surface multicostellate, costellae numbering 2 or 3 to the millimeter at
the front margin.

Pedicle valve moderately concave in lateral profile, broadly concave in anterior
profile. Beak small, umbo subcarinate, the angulation continued anteriorly as
a low and narrow fold nearly to the front margin. Fold at front margin broad
and shallow. Flanks bounding fold concave. Posterolateral and lateral extremi-
ties flattened. Interarea short, apsacline. Pedicle muscle field subquadrate,
moderately large.

Brachial valve evenly and gently convex in lateral profile, broadly and gently
convex in anterior profile but with the middle marked by a narrow depression.
Umbo sulcate, sulcus extending to anterior margin, narrow in the posterior two-
thirds but widening anteriorly. Flanks bounding sulcus narrowly rounded; lat-
eral slopes short, moderately steep.

954 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—Holotype, length 15.1, brachial length 15.1, midwidth
20.6, hinge width 13.8, thickness 3.6.

Types.—Holotype: 116964a; figured paratype: 116964b.

‘Horizon and locality—Lower Hermitage formation in Tennessee: Along
Tennessee Highway 53, 1 to 14 miles south-southeast of Woodbury (15’)
Quadrangle.

Discussion —The generic identity of this species has caused considerable diffi-
culty. The species was at first thought to be a member of the Dinorthidae but
flakes of the shell heated in a blast lamp showed definite punctae. As a dalmanel-
lid the genus Onniella seems the most likely assignment at the present time, but
the species is resupinate and is the only member of the genus Onmniella having
this profile. It is probable that the species belongs to a genus not yet described.

Paratype 116964b was roasted in a blast lamp and part of the shell pealed
off to reveal the pedicle muscle field. This proved to be subquadrate, but details
of the brachial interior were not clear because of partial silification of the shell
and crystallinity of the matrix. The brachial processes are flat blades like those
of Onniella.

ONNIELLA FERTILIS (Ulrich)
Plate 157, A, figures 1-3; plate 157, C, figures 5, 6; plate 150, E, figures 21-37

Orthis (Dalmanella) testudinaria Hayes and UtricH (not Dalman), U. S. Geol. Surv.,
folio 95, Illustr. Sheet, figs. 42, 43, 1903.

Orthis (Dalmanella) fertilis Ulrich in BASsLer, Virginia Geol. Surv. Bull. 2A, p. 182, pl. 24,
fig. 5, 1909.

Shell large for the genus, planoconvex ; width about 13 times the hinge width;
posterolateral extremities narrowly rounded ; sides moderately rounded ; anterior
margin strongly rounded ; anterior commissure rectimarginate to slightly sulcate.
Costellae generally 2 to 1 mm. at the front margin, in places 3 to the millimeter.

Pedicle valve gently convex in lateral profile with the maximum convexity in
the umbonal region; anterior profile broadly triangular, the median region nar-
rowly convex to carinate with long, gently dipping lateral slopes. Beak small,
low ; umbo narrowly convex, the convexity continued anteriorly as an indistinct
fold; interarea short, curved, apsacline.

Brachial valve nearly flat in both profiles; umbo narrowly sulcate, the sulcus
extending anteriorly to the front margin but scarcely widening anteriorly ; lateral
regions gently concave to nearly flat; posterolateral extremities flattened and
deflected slightly toward the pedicle valve.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (117360a)......... 16.0 15.3 20,1 12,0 4.5
% CR ETSO0RL) «Sita a aioe 12.8 12.3 15.8 [Ls 5.0

Types.—Lectotype: 96362b; paratypes: 96362a,c,d; figured hypotypes:
117369a-d, 123238a,b.
Horizon and locality—Curdsville formation in Virginia: On U. S. High-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 955

way 58, 3 to 34 miles east of Cumberland Gap, Wheeler (T.V.A. 153-SE)
Quadrangle ; Pennington Gap, Lee County.

Same formation in Tennessee: Lat. 36°17'31”, long. 83°53'55”, 4 mile north
of Sill (locality now under waters of Norris Lake), White Hollow (T.V.A.
145-SW) Quadrangle.

Discussion.—This species is characterized by its large size, nearly flat brachial
valve, and fairly fine costellae. The species has been widely identified on the
west side of the Appalachians, in Kentucky and West Tennessee. The species
is fairly characteristic in Curdsville rocks, but references to it in the Hermitage
formation are probably erroneous.

The authorship and type specimen of this species need explanation and de-
scription. In his reference to the species on page 82, Bassler (1909) gives Ulrich
as the author. In the plate legend no author’s name is used. Inasmuch as there
is no description of the species by Bassler and none has ever been given since
1909, it seems apparent that Bassler was citing a species Ulrich had studied and
intended to describe.

In the plate legend (pl. 24) no enlargement is given for the specimen illus-
trated. Comparison of the specimen and picture indicate an enlargement of
x14. The specimens, except for one, are thus all small individuals. The ex-
ception mentioned is the pedicle interior of a large specimen, and a brachial in-
terior of nearly the same size appears on the same piece. This is not shown in
the illustration but must be numbered among the cotypes. Comparison of the
illustrated slab with a good suite of shells of all sizes from the Curdsville forma-
tion, 54 miles northeast of Maynardville, Tenn., on Tennessee Highway 33
shows that the small individuals so abundant on the type slab are actually the
young of a larger form. The larger forms from Maynardville are identical with
the large interiors on the type slab. The writer therefore selects as type of the
species the brachial interior mentioned above and here designated 96362b. This
specimen shows the generic characters well.

Several localities and stratigraphic levels produce Onniellas strongly sugges-
tive of O. fertilis. Most of these are undescribed species outside the scope of
this monograph. Onniella fertilis differs from O. planoconvexa from the Hermi-
tage of West Tennessee in its greater size and more transverse form.

ONNIELLA PAQUETTENSIS Sinclair

Onniella paquettensis SINCLAIR, Canadian Field-Nat., vol. 59, No. 3, p. 73, pl. 2, figs. 2, 3,
1945.

Horizon and locality—Rockland formation in Ontario, Canada: Paquette
Rapids on the Ottawa River.

ONNIELLA ? PLANOCONVEXA Cooper, new species
Plate 161, C, figures 23-36

Shell of about medium size for the genus, roundly elliptical in outline, with
strongly rounded sides and anterior margins. Anterior commissure faintly sul-

956 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

cate. Hinge narrow; cardinal extremities rounded. Costellae numbering 2,
rarely 3, to the millimeter at the front margin.

Pedicle valve shallow, gently convex in lateral profile, broadly triangular in
anterior profile, the median region subcarinate, the sides flat, long, and mod-
erately steep. Umbo and median region narrowly convex and forming a nar-
row, low fold to the anterior margin. Beak low, small; interarea short and
strongly curved. Interior with small teeth and short, flaring dental plates ; muscle
area heart shaped, wide.

Brachial valve nearly flat in lateral profile; very gently convex in anterior
profile but with the median region gently depressed by a sulcus. Umbo sulcate,
the sulcus widening to the anterior margin where it is broad and shallow. Flanks
bounding sulcus gently swollen; lateral slopes gentle. Brachial interior with
small brachiophores having short supporting plates which are united to the
median ridge; cardinal process small with slender shaft and small myophore.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EEOOLY Pe sine aie aes ete we ere 10.2 9.8 11.5 6.5 3.9
Paratype (11737048) Uii.F 02: Li 11.4 13.0 Fi) 4.2

Types.—Holotype: 117370b; figured paratypes: 117365c-e, 117370a; un-
figured paratypes: 117365a,b.

Horizon and locality—Base of Hermitage formation in Tennessee: Along
Tennessee Highway 53, from 0.7 to 1.5 miles south of Woodbury, Woodbury
(15’) Quadrangle.

Discussion.—This species has usually been referred to Onniella fertilis (UI-
rich) but the Curdsville form is a larger shell, more transversely elliptical in
outline, more convex, and with a proportionally wider hinge. The Hermitage
species is distinctly subcircular in outline.

Genus PAUCICRURA Cooper, new name
(Latin paucus, few; crus, leg)

Dalmanella ScHucHERT and Cooper (not Hall and Clarke), Mem. Peabody Mus. Nat. Hist.,
vol. 4, pt. I, p. 120, 1932.

In amplifying Bancroft’s genus Resserella, Schuchert and Cooper (1932
p. 126) restricted Bancroft’s designation of Orthis canalis Sowerby, 1839, in
Murchison, Silurian System, to the specimen illustrated on plate 13, figure 12a,
as type of the genus. This selection now proves most unfortunate because the
specimen chosen is a member of the genus Parmorthis. The two genera, Res-
serella and Parmorthis, are thus synonyms, and the latter must be suppressed
in favor of Resserella which is the older genus. The large series of shells
formerly assigned to Resserella are thus left without a name. I propose Pauci-
crura to serve in this capacity and designate Orthis rogata Sardeson as type
species of the genus. The familiar Silurian Parmorthis thus becomes Resserella
and our Resserellas, which are numerous, become Paucicrura.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 957

I am grateful to Dr. C. J. Stubblefield, Geological Survey of Great Britain,
London, for calling my attention to this unhappy situation.

PAUCICRURA MATUTINA Cooper, new species
Plate 150, B, figures 6-11

Shell of about medium size for the genus, subcircular in outline; hinge mod-
erately wide; sides gently rounded, anterior margin more strongly rounded;
anterior commissure faintly sulcate; costellae moderately strong, 2 or 3 to the
millimeter at the anterior margin.

Pedicle valve gently convex in lateral view ; triangular in anterior profile and
with flat, long, moderately steep lateral slopes; umbo narrowly convex, the con-
vexity continued anteriorly to beyond the middle where it becomes less strong ;
anterior slope gently convex, long, and gently inclined; beak small; interarea
moderately long, gently curved, apsacline. Interior with strong teeth, short and
stout dental plates.

Brachial valve very gently convex in both profiles but with the anterior pro-
file depressed medially by a shallow sulcus. Umbo sulcate, sulcus widening an-
teriorly and becoming shallower in the same direction; flanks bounding sulcus
gently inflated. Interior with stout, short, slightly divergent brachiophores,
median ridge low, cardinal process with long shaft but small myophore.

Measurements in mm.—Holotype, length 7.3, brachial length 6.7, width 7.9,
hinge width 6.2, thickness 3.2.

Types.—Holotype: 111795a; figured paratypes: 117366a,b.

Horizon and locality Edinburg formation (lower Cyrtonotella zone) in Vir-
ginia: In the ravine at the switch just east of Strasburg Junction, Strasburg
(15’) Quadrangle.

Shippensburg formation (Pinesburg member-lower part Echinosphaerites
zone) in Pennsylvania: Along the railroad 2 miles southwest of Marion, Cham-
bersburg (15’) Quadrangle.

Same formation in Maryland: On U. S. Highway 40, on the west bank of
Conococheague Creek, 7 miles west of Hagerstown, Williamsport (15’) Quad-
rangle.

Discussion.—This species is one of the earliest dalmanellids so far found in
the United States. It is characterized by subcircular outline, moderately wide
hinge, fine costellae, and moderately deep sulcus. It is close to P. virginica but
has stronger costellae, a less deep sulcus and a more gentle fold on the pedicle
valve.

PAUCICRURA ROGATA (Sardeson)
Plate 157, F, figures 18-24

Orthis rogata SaRvEsoN, Minnesota Acad. Nat. Sci., Bull. 3, p. 331, pl. 5, figs. 1-4, 1892;
Amer. Geol., vol. 19, p. 95, pl. 4, figs. 1-10, 1897.

Orthis (Dalmanella) testudinaria (Winchell and Schuchert, not Dalman), WincHELL and
ScHucHERT, Geol. Minnesota, vol. 3, p. 441, pl. 33, figs. 17-22, 1895.—HALL and CLarkgE,
Pal. New York, vol. 8, pt. 1, pl. 5B, figs. 27-31, 1892.

958 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Dalmanella rogata (Sardeson) ScHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist.,
vol. 4, pt. I, p. 120, pl. 17, figs. 2-5, 7, 13, 31, 1932.

Figured specimens.—48701a,b.

Horizon and locality—Upper Decorah (Ion shale—Fucoid bed) and lower
Prosser (Vellamo bed) in Minnesota: At Spring Valley, Fillmore County ;
Cannon Falls, Goodhue County ; St. Paul; Kenyon, Goodhue County ; Rochester,
Olmsted County ; Fountain, Fillmore County; Warsaw, Rice County.

Same formation in Wisconsin: At Mineral Point, Mineral Point (30’) Quad-
rangle ; Highland, lowa County.

Auburn chert in Missouri: $ mile east of Auburn, Elsberry (15’) Quadrangle.

PAUCICRURA SUBPLANA Cooper, new species
Plate 159, D, figures 14-20

Shell of about moderate size for the genus, slightly wider than long; sides
and anterior margin strongly rounded; anterior commissure faintly sulcate.
Finely costellate and with about 70 costellae around the margin of the pedicle
valve.

Pedicle valve fairly strongly convex in lateral profile and with the maximum
convexity in the posterior half; anterior profile roundly subcarinate and strongly
arched; umbonal region narrowly swollen; median region swollen and with a
steep anterior slope; sides flattened but steep ; interarea short, curved ; beak small.

Brachial valve nearly flat in lateral profile; anterior profile slightly convex
and depressed medially by a shallow, narrow sulcus; sulcus originating at the
umbo, broad and shallow, almost obsolete at the front margin. Flanks slightly
swollen and with short, gentle slopes to the margins.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
FplOty@el Ure <A eet srs 10.0 9.2 10.6 6.5 4.5
Paratype. Lass ke eke vs 0.1 8.5 10.0 6.4 4.2

Types.—Holotype: 123237a; figured paratype: 123237b.

Horizon and locality—Martinsburg formation (part with Brongniartella=
Salona) in Virginia: On County Highway 617=910, 0.15 mile north of Green
Mount Church, Broadway (15’) Quadrangle.

Discussion.—This species is characterized by its fine costellae and the nearly
plane brachial valve. It is separated from Dalmanella sculpta, with which it
occurs, by these features. Although the interior is at present not known, the
species is referred to Paucicrura because of the nearly flat brachial valve. It
differs from P. virginica in being more circular and in having much finer costel-
lae. The species is suggestive of P. rogata, but that species has a wider hinge
and distinct shoulders as well as stronger ornamentation.

PAUCICRURA VIRGINICA Cooper, new species
Plate 159, A, figures 1-5; plate 160, A, figures I-10

Shell of about usual size for the genus, slightly wider than long, subquadrate
to subcircular in outline; hinge wide, greatest width at about the middle; sides

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 959

and anterior margin gently rounded; anterior commissure faintly sulcate. Cos-
tellae measuring 3 to the millimeter at the anterior margin.

Pedicle valve gently convex in lateral profile; subcarinate in anterior profile
with flat, moderately steep sides. Umbo and median region subcarinate, the fold
continued to the anterior margin. Flanks bounding fold flat and moderately
steep. Beak erect, gently incurved ; interarea long and wide, apsacline. Interior
with large teeth, stout but short dental plates; narrow and short muscle field.

Brachial valve gently convex in lateral profile and with the anterior quarter
bent more or less strongly toward the pedicle valve; anterior profile broadly and
gently convex but with the median region depressed. Umbo sulcate; sulcus
widening and deepening anteriorly and forming a broad V. Flanks bounding
sulcus very gently convex; posterolateral areas sloping gently. Interior with
stout and moderately long brachiophores ; brachiophore supports obscure; cardi-
nal process variable, small; median ridge strong. Adductor pairs subequal.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Paratype.) (EI730GH) oa ats = 8.2 aS Q.1 6.9 4.0
“ CEI74GSt) . oe sas 8.1 7.6 8.5 7.1 4.1
< CTi7 ZS) AVS. 7.8 7.4 7.7 7.1 3.9

Types.—Holotype: 117368b; figured paratypes: 117367a, 117368c-g,
123235a-d; unfigured paratypes: 117368a,h-j.

Horizon and localty.—Edinburg formation (low to middle Nidulites zone)
in Strasburg (15’) Quadrangle, Virginia: On U. S. Highway 11, 1 mile north of
Strasburg ; beside the road along Tumbling Run, 14 miles southwest of Strasburg.

Siltstone in the Edinburg formation (Liberty Hall facies 30 feet above Echino-
sphaerites) in Virginia: 4 mile south of Virginia Highway 274, 14 miles south-
west of Wadesville, Winchester (15’) Quadrangle.

Discussion.—This species is characterized by its squarish outline, fairly wide
hinge, fine costellae, deep sulcus, and strong, subcarinate fold. Another com-
mon feature of this shell is that it develops strong plaits of growth at the anterior
margin. This species differs from P. matutina in having finer costellae, deeper
sulcus and more prominent fold, and a generally larger size.

EREMOTREMA Cooper, new genus

(Greek eremo, solitary; trema, opening)

Shells small, biconvex, subcircular to subquadrate, lateral margins rounded;
anterior margin strongly rounded ; anterior commissure rectimarginate; surface
costellate, costellae fine, rounded, increasing by implantation in 4 generations.
Punctate.

Pedicle valve somewhat deeper than the brachial valve, gently convex in pro-
file; beak small, incurved ; interarea long, nearly orthocline. Interior with thick,
large teeth; delthyrial cavity deep and narrow; muscle area rhomboidal in out-
line ; muscle scars deeply inserted, diductors long and narrow with their anterior
ends approximate. Adductor track long and slender, obscure; pallial impressions

960 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

originating at anterior end of diductors, close and separated by a low, narrow
median ridge. Dental plates obsolete.

Brachial valve moderately convex in both profiles; fairly strongly sulcate at
the beak and umbo but sulcus nearly disappearing near the middle. Brachio-
phores a stout blade with a poorly defined crus given off from the inner end;
sockets deep; notothyrial cavity choked by excess shell supporting the inner
sides of the brachiophores; cardinal process with short, stout shaft and lobate
myophore, the middle lobe of the myophore forming a high, narrow ridge. Me-
dian ridge low and stout, separating the small adductor scars.

Genotype—Eremotrema biconvexum Cooper, new species.

Discussion.—This genus has obvious affinities with Paucicrura in the cardi-
nalia of the brachial valve, but the shape, outline, and interior of the pedicle
valve present important differences from that genus. Eremotrema is character-
ized by its subequally convex valves, long interareas on both valves, nonfascicu-
late costellae, rhomboidal muscle area, and stout, encrusted cardinalia.

Eremotrema differs from Paucicrura in the fairly strongly biconvex outline,
that of Paucicrura being gently biconvex to planoconvex. The major difference
is inside the pedicle valve, that of Eremotrema not having well-defined dental
plates, ponderous teeth, and a muscle field with rhomboidal outline. The diductor
scars in the muscle field are elongate and terminate with their anterior ends close
together, which is quite unlike that of Paucicrura in which the anterior end of the
muscle field is bilobate. The pallial trunks of Eremotrema are unlike those of
Paucicrura but are suggestive of Paurorthis in being parallel and separated only
by a low median ridge. The vascula media of Paucicrura are usually strongly
divergent, not convergent as in Eremotrema.

Inside the brachial valve the cardinalia are like those of Paucicrura but are
more exaggerated. Moreover, all the structures are thickened. The brachio-
phores are supported by shell substance deposited on their inside. The cardinal
process, unlike that in Paucicrura, protrudes from the notothyrium and projects
beyond the margins of a long interarea.

EREMOTREMA BICONVEXUM Cooper, new species
Plate 146, G, figure 62; plate 160, E, figures 31-45

Subquadrate to subcircular in outline ; sides gently rounded to nearly straight;
widest just anterior to the middle; anterior margin broadly rounded; antero-
lateral extremities narrowly rounded; anterior commissure rectimarginate.
Valves subequally convex; surface costellate, costellae fine, rounded, separated
by spaces equal in width to the width of the costellae ; 3 costellae to the millimeter’
at the front margin and 4 costellae to the millimeter on the sides.

Pedicle valve gently convex in lateral profile; anterior profile with the median
region elevated and long, moderately steep slopes to the margins. Beak small,
well defined, incurved; umbo narrowly convex, forming a subcarinate fold that
disappears at about the middle of the valve. Median region swollen; lateral
slopes gently convex. Interarea nearly orthocline, gently curved, long; del-
thyrium long and narrow.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 961

Brachial valve gently convex in lateral profile ; anterior profile broadly convex,
flattened in the median region and gently depressed at the middle ; umbo sulcate ;
sulcus narrow but moderately deep, extending only to the valve middle ; anterior
slope long, moderately steep; median region somewhat swollen; lateral slopes
short but moderately steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype WPis.’. 232 «5 11.3 10.1 II.I 9.0 5.2
Paratype (117347a)... 8. 7.3 8.7 6.9 4.2

Types——Holotype: 117350a; figured paratypes: 117347b, 117348a, 117349,
117350b,c; unfigured paratypes: 117347a, 117348b, 117350d,e.

Horizon and locality—Benbolt formation (lower) in Virginia: On the south
side of Mount Hagan School, Hilton (T.V.A. 197-NW) Quadrangle; east bank
of sinkhole, 300 feet south of Lakeview Church on Virginia Highway 71, Moll
Creek (T.V.A. 196-SE) Quadrangle; 0.2 mile south of the middle fork of
Moccasin Creek, 14 miles south of Hansonville, Hansonville (T.V.A. 205-SW)
Quadrangle; 4 mile southeast of Richpatch, Eagle Rock (15’) Quadrangle.

Discussion—At present no other species of this genus is known with which
E. biconvexum can be compared. The species is easily recognized by its form,
fine costellae, thick valves, and ponderous cardinalia.

CRISTIFERINA Cooper, new genus

(Latin crista, crest; fero, bear)

Shell smail, less than 4 inch in width, subelliptical to subcircular in outline ;
valves unequally convex, the brachial valve having less depth than the pedicle
valve; anterior commissure gently sulcate; surface multicostellate, narrowly
rounded, and strongly elevated, costellae increasing in number by intercalation.

Pedicle valve with stout teeth having large fossettes; dental plates short and
stout ; delthyrial cavity deep ; muscle area heart shaped; diductor scars protrud-
ing anterior to the ends of the dental plates and forming 2 lobes at the front of
the muscle field. Traces of somewhat divergent vascula media separated by a
low median ridge appear in some specimens.

Brachial interior with moderately long bladelike brachiophores having short,
sharp crura protruding from their inner end; brachiophores supported by strong
swelling of the notothyrial platform; sockets deep; no fulcral plates; cardinal
process with short, grooved shaft, expanded myophore; surface of myophore
with large, recurved median plate; median ridge strongly elevated. Adductor
field small.

Genotype.—Cristiferina cristata Cooper, new species.

Discussion.—This genus is best recognized by its small size, strong costellae,
deep pedicle valve and moderately convex brachial valve, and the character of
the cardinalia, particularly the bizarre development of the cardinal process. As
far as known the genus is rare.

The exterior of Cristiferina is strongly suggestive of Paucicrura of the Decorah

962 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

shale in the United States and of Soudleyella in the British sequence. It seems
to be more strongly costellate than either of these two, and the interior of the
brachial valve is different from that of both of them.

The pedicle interior of Cristiferina is not distinctly marked off from that of
many other dalmanellids, but the brachial interior is distinctive. None of the
specimens of the brachial interior shows a stage with fulcral plates although the
brachiophores are very much like those of Paucicrura. An unusual feature of
Cristiferina is the preservation of the crura. These are rarely seen structures
in the punctate orthids, but they are well displayed as short, sharp points given
off at an angle to the brachiophore. The crus protrudes from the inside end of
the brachiophore.

The cardinal process of Cristiferina is the most distinctive feature of the genus,
but it is quite variable. The shaft is short, usually stout and usually marked by
a shallow median depression. The part of the cardinal process facing the in-
terior of the pedicle valve is expanded laterally at the end of the shaft. The
posterior face of the myophore thus forms a triangle. Down the center of this
triangle extends a high, thin crest which divides the myophore. In lateral view
this crest is notched just posterior to its junction with the myophore. Although
some other dalmanellids have a crested myophore, none is developed to the
degree seen in Cristiferina.

CRISTIFERINA CRISTATA Cooper, new species

Plate 157, E, figures 15-17; plate 157, G, figures 25-29; plate 158, C, figures 12-14;
plate 160, C, figures 16-28; plate 160, D, figures 29, 30

Subcircular in outline, sides and anterior margins well rounded; anterior mar-
gin gently sulcate ; costellae numbering 2, rarely 3 to the millimeter at the front
margin.

Pedicle valve fairly evenly and moderately convex in lateral profile; anterior
profile strongly convex and with long, moderately steep slopes ; beak moderately
long, strongly incurved; umbo narrowly convex, the convexity extending to a
point anterior to the middle but becoming vague thereafter ; anterior slope short
and steep; lateral slopes long and steep. Interarea moderately long, curved,
apsacline. Delthyrium nearly plugged by the crest of the cardinal process.

Brachial valve gently and fairly evenly convex in lateral profile ; anterior pro-
file broadly and gently concave in the median region but with gently convex lat-
eral areas; median region fairly strongly sulcate, the sulcus extending nearly to
the anterior margin but becoming very shallow in its anterior limit. Flanks
bounding sulcus gently swollen; lateral slopes short and gentle.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
FYGIOtY pe 1. Seis 2s sere ue ps 6.6 77, 5.0 3.9
Paratype (111794e)..... 7.0 6.2 7.1 5.1 3.2

Ff (111794h)..... 0.3 8.5 9.1 6.5 4.3

|

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 963

Types.—Holotype: 111794g; figured paratypes: 111794b-d, 117351a,c,
117352n,0, 117353, 117354a,b; unfigured paratypes: 1117942,e,f,h, 117351b,d-m;
figured specimen: 117358a.

Horizon and locality—Chatham Hill formation in Virginia: 1.2 miles S. 31°
E. of Sharon Springs, Burkes Garden (15’) Quadrangle; Grayson Farm, 4 miles
southwest of Bland, Bland County.

Edinburg formation (Cyrtonotella zone) in Virginia: 4 mile west of Stras-
burg, Strasburg (15’) Quadrangle.

Botetourt formation (Cybeloides zone) in Virginia: Opposite dam on North
Fork of Shenandoah River, north side, 1.5 miles N. 61° E. of Edinburg, Edin-
burg (15’) Quadrangle.

Discussion.—This species is characterized by small size, strong costellae, and
circular outline. It also represents a full development of the bizarre characters
of the cardinal process. The species is one of the earliest known of the dalmanel-
lid brachiopods on this continent. It differs from C. cristifera in its smaller size
and more rotund form.

CRISTIFERINA CRISTIFERA Cooper, new species

Plate 158, B, figures 6-11; plate 159, C, figures 12, 13; plate 160, B, figures 11-15;
plate 161, D, figures 37, 38

Shell large for the genus, subcircular in outline; hinge moderately wide;
greatest width at about the middle; sides gently rounded; anterior margin
strongly rounded; anterior commissure gently sulcate. Costellae 2 or 3 to the
millimeter at the anterior margin.

Pedicle valve fairly strongly convex in lateral profile; anterior profile strongly
domed ; umbo narrowly convex, the convexity broadening and finally disappear-
ing toward the front margin; median region swollen; anterior slope convex,
long, and steep ; lateral slopes long and steep. Interarea moderately long, curved,
apsacline. Dental plates short and thick; muscle field small, narrow; vascula
media moderately developed.

Brachial valve gently convex in lateral profile; broadly and gently convex in
anterior profile and with the median region depressed and the lateral slopes short
and steep. Sulcus narrow and shallow, extending from umbo to anterior margin
where it is shallowest. Flanks bounding sulcus slightly convex. Brachiophores
short and thick; notothyrial cavity choked by a greatly thickened cardinal proc-
ess with enormous median plate which fills the delthyrium.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotypei Gi. Soa, 0.4 8.6 9.3 7.0 5.0
Paratype (117357a)... 10.6 10.0 10.7 8.0 4.8

Types.—Holotype: 117356a; figured paratypes: 117355a, 117357b; figured
specimen: 117358a; unfigured paratype: 1173574.

Horizon and locality—Oranda formation in Virginia: On the Bowman Farm,
about I mile southwest of the center of Woodstock and 0.3 mile east of U.S.

964 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Highway 11, Edinburg (15’) Quadrangle; opposite dam, North Fork of the
Shenandoah River, 14 miles N. 61° E. of Edinburg, Edinburg (15’) Quad-
rangle; U. S. Highway 11, 14 miles southwest of Strasburg, Strasburg (15’)
Quadrangle.

Discussion—This species has the large and prominent myophore crest of the
genus, but is large and circular in outline. It is more finely costellate and larger
than C. cristata, the only other known species of the genus. Tentatively referred
here are some specimens occurring just under the Eureka quartzite in dark shales
in Nevada on the north-facing nose of hill 8167, Martins Ridge, Roberts Moun-
tains (1°) Quadrangle. This occurrence emphasizes the strong faunal relations
between this shale and the Oranda formation of Virginia.

Genus HOWELLITES Bancroft, 1945
HOWELLITES sp.
Plate 145, E, figures 29, 30
Howellites BANcRorT, Journ. Paleont., vol. 19, No. 3, p. 203, 1945.

Figures of the exterior and interior of the brachial valve of Howellites are
introduced for comparison with Paucicrura, Cristiferina, and Eremotrema.

Figured specimen.—83859a.

Horizon and locality—Upper Ordovician (Soudleyan), Allt Fawr, Meifod
District, Montgomeryshire, Wales.

Family PAURORTHIDAE Opik, 1933

Dalmanellacea with a simple cardinal process, brachiophores simple and sup-
ported by notothyrial platform.

Genus PAURORTHIS Schuchert and Cooper, 1931

Paurorthis ScHUCHERT and Cooper, Journ. Paleont., vol. 10, No. 7, p. 243, 1931; Mem.
Peabody Mus. Nat. Hist., vol. 4, pt. 1, p. 79, 1932.—Or1x, Acta et Comment. Univ. Tartu,
ser. A, vol. 25, No. I, p. II, 1933.

PAURORTHiIS CATAWBENSIS Butts
Plate 151, G, figures 30-36; plate 162, D, figures 19-23
Paurorthis catawbensis Butts, Virginia Geol. Surv. Bull. 52, p. 67, pl. 80. figs. 11-13, 1942.

Shell of about average size for the genus, slightly wider than long with great-
est width at about the middle. Cardinal extremities rounded. Lateral margins
gently rounded, anterior margin narrowly rounded. Anterior commissure broadly
sulcate. Surface multicostellate ; costellae rounded, with very narrow interspaces.
Fascicles low ; about 5 costellae in the space of I mm. at the front.

Pedicle valve moderately convex with the greatest convexity located in the
umbonal region when seen in lateral profile. Narrowly rounded in anterior pro-
file. Fold obscure, defined as a longitudinal swelling extending from the beak

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 965

to the anterior margin. Lateral slopes moderately steep. Beak low; interarea
short, strongly curved.

Brachial valve with the greatest convexity in the posterior half. Sulcus shal-
low, narrow at the umbo, widening anteriorly, but never conspicuots. Anterior
profile very gently convex ; areas bounding the sulcus very gently swollen. Slopes
to cardinal extremities gently concave, moderately steep.

Interior of pedicle valve with a subcordate muscle field ; diductor and adductor
tracks subequal; median ridge low and short. Brachial valve with short, stout
brachiophores, narrow and deep notothyrial cavity, and rudimentary cardinal
process.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Lectotype (brachial valve) .......... ? Fis) 9.2 7.0? y
Hypotype (pedicle valve 117276a).... 7.3 ? 10.0 8.0? ?
me Cee Be 7 i710 em ? 10.3 8.0? ?
a (brachial valve 117276b)... ? 8.5 9.4 6.0 ? 2
e (aeReaIC) 2. Su. cas Se 6.9 6.6 9.0 6.5 4.2

Types.—Lectotype : 99259c; paratypes: 99259a,b; figured hypotypes: 117275,
117276a-e ; 117277d, 117278a,b; unfigured hypotypes: 117276f,g, 117277a-c.

Horizon and locality—Botetourt formation in Virginia: At the junction of
Virginia Highways 311 and 114, 4 mile southwest of Catawba, Salem (15’)
Quadrangle; junction of Virginia Highways 731 and 724, 2 miles northwest of
Brownsburg, Lexington (15’) Quadrangle; south side of the road 0.2 mile east
of Strasburg Junction, Strasburg (15’) Quadrangle.

Arline formation in Virginia: In the quarry at Marion, Marion (T.V.A.
218-SE) Quadrangle.

Blockhouse formation in Tennessee: 1.6 miles south-southwest of Toqua
School, Vonore (T.V.A. 139-SE) Quadrangle.

Discussion.—The types of this species are impressions of the inner and outer
surfaces in a soft shale. The species is characterized by a roundly elliptical out-
line but with distinct shoulders in the posterior region. Costellae and fascicles
are fine and crowded. It is not so strongly fasciculate as the Friendsville and
Little Oak species. It is somewhat more finely costellate and with less prominent
fascicles than P. macrodeltoidea from the Bromide formation. It is not so
strongly sulcate as P. spinosa from the Edinburg formation.

PAURORTHIS FASCICULATA Cooper, new species
Plate 150, B, figures 17-24; plate 151, C, figures 12-18; plate 155, B, figures 11-13
Deliatreta elegantula Butts (part), Alabama Geol. Surv., Special Rep. 14, pl. 18, fig. 27, 1926.

Shell of about medium size for the genus, with both valves strongly convex
and the hinge equal to about seven-tenths the width. Cardinal extremities obtuse.
Length and width subequal. Lateral margins moderately well rounded; anterior
margin broadly rounded. Surface fascicostellate with the costellae bundled into
a number of well-defined and elevated fascicles; 2 fascicles occupy the sulcus of

966 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the brachial valve, and 2 strong fascicles bound the sulcus. Median fascicle of
the pedicle valve forming a low fold; 4 distinct fascicles present on the lateral
slopes flanking the median fascicle.

Pedicle valve moderately convex in lateral profile with the maximum con-
vexity located near the middle. Anterior profile narrowly rounded and with steep
lateral slopes. Interarea apsacline, curved; beak incurved.

Brachial valve moderately convex in lateral profile; gently convex in anterior
profile and with the center slightly depressed at the sulcus. Sulcus originating
at the umbo, deepest near the middle and becoming broad and shallow at the
anterior. Flanks bounding sulcus slightly swollen. Slopes to the cardinal ex-
tremities steep, slightly concave. Interarea moderately long, gently curved.

Interior of pedicle valve with fairly well developed vascula media but poorly
defined median elevation. Median ridge of brachial valve low; cardinal process
not preserved, or rudimentary.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EVONGEI DE is ns as soc ad os 8.0 a7 9.6 6.9 4.8
Paratype (117279a).... 9.6 8.9 10.6 8.6 6.8

Types.—Holotype: 117280a; figured paratypes: 117279a, 117280b,g; un-
figured paratypes: 117279b-e, 117280c-f.

Horizon and locality.—Little Oak formation in Alabama: At the intersection
of the Bailey Gap and Cahaba Valley roads, SW4SW35 sec. 13, T. 19 S., R. 2 W.,
13 miles northeast of Newhope Church, Vandiver (15’) Quadrangle; 1 mile
northeast of Pelham, 2 miles north of Pelham, on the west side of U. S. High-
way 31, 4 mile north-northeast of Pelham, Bessemer Iron District (15’) Quad-
rangle.

Arline formation (middle) in Tennessee: On north side of wagon road in
glade, + mile southeast of Friendsville, Concord (T.V.A. 138-SW) Quadrangle.

Tellico formation in Tennessee: On Chapman Highway (Tennessee 71),
1.3 miles east-northeast of Cusick, Walden Creek (T.V.A. 156-SW) Quad-
rangle; BM-LHT 1366, 1 mile southeast of Chilhowee View School, Blockhouse
(T.V.A. 148-NW) Quadrangle.

Discussion.—This species is characterized by the strength of the fasciculation
of its costellae. The fascicles are more regularly developed than in any other
species described herein.

PAURORTHIS FASCIFERA Cooper, new species
Plate 140, D, figures 26-29

Shell small, wider than long, with the greatest width slightly posterior to the
middle. Sides gently rounded; anterior margin somewhat narrowly rounded;
anterior commissure gently sulcate; fascicostellate, fascicles strong and promi-
nent, generally consisting of 3 costellae.

Pedicle valve gently convex in lateral profile with the greatest depth just an-
terior to the umbo; anterior profile narrowly convex in the median region with

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 967

long, steep slopes. Median region folded medianly. Beak narrow, strongly in-
curved, Interarea curved, steeply apsacline.

Brachial valve evenly and moderately convex in lateral profile, broadly and
gently convex in anterior profile. Sulcus broad and shallow; flanks gently in-
flated, with short and moderately steep slopes.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
PIOIGEV DG 6 aidseis «x alc ates E- 6.7 8.1 6.0 4.5
Paratype (117281b)..... 7.6 7.2 9.0 UE 4.2
o (UIZZ5TOa ac. 6.8 6.5 7.9 6.4 3.9

Types.—Holotype: 117281a; unfigured paratypes: 117281b-d.

Horizon and locality—Ward Cove formation in Fountain City (T.V.A.
146-SW) Quadrangle, Tenn.: Inskip, military coordinates E-2, 604, 600-
700/N596, 350; Hickey place, 2 miles southwest of Hall Crossroad.

Discussion.—This is a rare species and is known only from a few silicified
specimens. It is strongly fasciculate, but the fascicles are narrower than those of
P. fasciculata. The species is more strongly sulcate and more strongly fasciculate
than P. catawbensis.

PAURORTHIS GIGANTEA Cooper, new species
Plate 260, F, figures 25-31

Large for the genus, subcircular in outline with the length and width nearly
equal; sides rounded; anterior margin rounded; hinge narrow, in width about
two-thirds the length. Anterior commissure gently sulcate. Surface fascicostel-
late, fascicles low, generally best defined near the valve middle. Costellae fine,
rounded, closely crowded, numbering 4 or 5 in 1 mm. at the front margin of an
adult.

Pedicle valve unevenly convex in lateral profile, the maximum curvature being
located in the umbonal region and the anterior two-thirds gently convex; an-
terior profile strongly domed. Median region from umbo to anterior margin
somewhat swollen to form an ill-defined fold; flanks gently swollen and steep.
Interarea long, curved; beak strongly incurved. Interior with deep delthyrial
cavity and prominent median ridge anterior to it.

Brachial valve less convex than the pedicle valve, gently convex in lateral pro-
file with the maximum convexity in the posterior third; anterior profile broadly
and gently convex. Anterior half flattened and bearing a poorly defined shallow
sulcus. Flanks gently swollen. Interarea long and curved. Interior unknown.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
FIGIOEVDE ic \s 2c cataract aek 19.0 17.8 18.2 13.1 II.1
Paratype .(124235b)......... 16.9 15.8 17.0 rit 9.0

Types.—Holotype: 124235a; figured paratype: 124235c; unfigured paratypes:
124235b, d-f.

968 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Horizon and locality.—Dark shale below the Eureka quartzite in Nevada: Be-
low two knobs of the Eureka quartzite, north side canyon, 3.1 miles N. 32° E.
of Blair (Segura) Ranch, Antelope Mountains, Roberts Mountains (1°) Quad-
rangle.

Discussion.—This species is characterized by its large size and fine costellae.
The only other American Paurorthis approaching it is P. ponderosa from the
Benbolt formation, but this does not attain the size of the western species. Fur-
thermore, P. ponderosa has narrower fascicles and a more carinate pedicle valve
than P. gigantea.

PAURORTHIS LONGA Cooper, new species
Plate 150, A, figures 1-16

Small, subrectangular in outline, with the length and width about equal; great-
est width at about the middle; sides nearly straight; anterolateral extremities
narrowly rounded; anterior margin rounded. Hinge narrower than the greatest
shell width. Anterior commissure sulcate. Surface fascicostellate.

Pedicle valve gently convex in lateral profile; strongly convex in anterior
profile and much deeper than the brachial valve; beak long, incurved; interarea
curved, moderately apsacline. Umbo and median region swollen from beak to
anterior margin and thus forming a fold; flanks gently inflated, steep.

Brachial valve moderately convex in lateral profile and with the maximum
depth in the posterior two-thirds; anterior third gradually geniculated toward
the pedicle valve; anterior profile broadly convex, with middle slightly concave.
Umbo and region immediately anterior to it strongly swollen; sulcus originating
at the beak, broad and shallow. Flanks full and with moderately steep slopes.

Interior of brachial valve with delthyrial cavity deep and long, dental plates
nearly obsolete; median ridge well developed, usually narrow and extending
nearly to the anterior margin. Delthyrium narrowed by lateral plates.

Brachial interior with thick brachiophores, prominent median ridge, and deeply
impressed adductor impressions.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hiplety pe |}: -wiseesai «6 8.3 72 7.7 6.6 5.4
Paratype (117282a)..... ORG 6.9 7.6 6.2 5.1
* (1972820) re 3% 8.4 TRE 8.1 6.7 5.0

Types.—Holotype: 117282b; figured paratypes: 117282a,c,e-k, 117283d; un-
figured paratypes: 117282d, 117283a-c,e.

Horizon and locality—Lower part of Arline formation in Tennessee: 100
yards southwest of the Negro Cemetery, 4 mile northeast of Friendsville ; + mile
east-southeast of Friendsville ; north side wagon road in glade, + mile southeast
of Friendsville; Concord (T.V.A. 138-SW) Quadrangle.

Discussion.—This species is related to P. fasciculata but is distinguished by a
thick shell and an elongate form. The sides are subparallel, and the fascicula-
tion is less regular than in P. fasciculata.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 969

PAURORTHIS MACRODELTOIDEA Cooper, new species
Plate 151, A, figures 1-6

Shell of about average size for the genus; hinge equal to about three-quarters
the width. Lateral margins well rounded, anterior margin broadly rounded. An-
terior margin sulcate. Surface fascicostellate, fascicles numerous but not well
defined. About 4 costellae in 1 mm. at the front margin.

Pedicle valve strongly swollen longitudinally to form an indistinct median fold
and giving the valve a subcarinate anterior profile. Slopes from the median fold
to the margin steep. Fullness of pedicle valve extended to the front margin, al-
though the convexity in the anterior portion is not so great as that in the umbo-
nal region. Interarea only moderately curved. Delthyrium partially closed by
lateral plates.

Brachial valve most convex in the umbonal region and posterior half; anterior
half somewhat depressed and anterior margin slightly extended at the sulcus to
form a short tongue. Sulcus originating at the umbo, shallow but widening and
deepening anteriorly. Flanks bounding sulcus gently swollen; slopes to cardinal
extremities slightly concave, moderately steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Eiplotype 420......e28< 10.0 8.8 10.6 7O7 5.0
Paratype (117284b).... 9.7? 8.6 10.4 78? 5.8
ss (6007285) Bios eee 9.2? 8.4 10.4 8.0 5.4

Types.—Holotype: 117284a; figured paratype: 117285; unfigured paratypes:
117284b-g.

Horizon and locality—Bromide formation (Pooleville member) in Murray
County, Oklahoma: Zone 13, 241 feet below Viola, Spring Creek, east of Poole-
ville, sec. 17, T. 2 S., R. 1 W.; West Spring Creek, sec. 6, T. 2 S., R. 1 W.

Discussion.—The occurrence of this genus in the Simpson sequence is inter-
esting because it is a link to the Southern Appalachians. The species is similar
to P. catawbensis and P. fasciculata of the Southern Appalachians but differs in
having stronger costellae than the former and less regular fasciculation than the
latter.

PAURORTHIS MAGNA Cooper, new species
Plate 149, C, figures 10-25; plate 149, E, figures 30-33; plate 149, F, figures 34-43

Shell large for the genus, slightly wider than long, valves strongly convex,
and hinge equal to a little less than three-quarters the width at the middle.
Cardinal extremities well rounded. Lateral and anterior margins broadly
rounded. Anterior commissure broadly sulcate. Surface fascicostellate, fascicles
consisting of 5 to 7 costellae. Fascicles not strongly elevated, a deep, narrow
groove extending from the umbo of the brachial valve to the front margin. On
the pedicle valve this groove represented by a costella stronger than those sur-
rounding it.

Pedicle valve moderately convex in lateral profile with the greatest convexity

970 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

in the vicinity of the umbo; anterior profile broadly and moderately convex.
Fold represented by a gentle longitudinal swelling from the umbo to the front
margin. Lateral slopes flat and moderately steep. Interarea short and strongly
incurved. Beak low, incurved.

Brachial valve with the greatest convexity at the umbo in lateral profile; an-
terior profile moderately convex but with a shallow depression in the medial
region. Sulcus shallow and broad, originating at the umbo but becoming indis-
tinct at the front of old shells. Posterior half of shell moderately swollen, an-
terior half depressed. Flanks bounding sulcus gently swollen. Lateral slopes
short, slightly concave and moderately inclined.

Interior of pedicle valve with muscle field usual for the genus but much thick-
ened at the front margin and with a thick callosity tapering anteriorly from the
margin. Adductor track thickened and elevated. Brachial interior with unusually
long brachiophores, cardinal process ranging from a thin septum to a thick boss,
and moderately elevated median ridge.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Holotype) AoE. Fe 12.2 10.9 13.8 9.9 5.9
Paratype (117286q)... 12.2 11.2 13.8 0.4? 6.5
ii (@a720rb.) .ah.72'5 T.3 nee 9.6 78
et (117291a)... 11.6+- 10.7 13.4 10.9 6.9
ue (8r7202b) . Ait II.2 12.4 Q.1 6.0

Types.—Holotype: 117287b; figured paratypes: 117286a-c,q, 117287a, 117288,
117289a, 117291a,b, 117292a-c (d missing) ; unfigured paratypes: 117286d-p,
117289b, 11729Ic.

Horizon and locality—Lincolnshire formation in Tennessee: 4 mile north-
west of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle; in Clinch Valley
at Shiloh Church near center northwest subquad., Pressmens Home (T.V.A.
171-NE) Quadrangle.

Same formation in Virginia: Along Tumbling Run, 14 miles southwest of
Strasburg, Strasburg (15’) Quadrangle.

Lincolnshire formation (Hogskin member) in Tennessee: Sally Cleveland
Farm # mile southwest of Washburn, Dutch Valley (T.V.A. 154-SE) Quad-
rangle; 0.4 mile east-northeast of Red Hill, 4 miles west-southwest of Thorn
Hill, Avondale (T.V.A. 162-SW) Quadrangle; road to Washburn 3 miles west-
southwest of Thorn Hill, Avondale (T.V.A. 162-SW) Quadrangle; $ mile north
and northwest of Eidson, Kyles Ford (T.V.A. 170-SE) Quadrangle.

Discussion.—This species attains an unusually large size for the genus but is
not the largest of the species known in the Appalachians. Its shape is somewhat
variable, but in general it is not so circular as P. ponderosa. The latter form is
a much thicker shelled species and attains a much larger size. The fascicles of
the Lincolnshire species are smaller and less prominent than those of P. pon-
derosa. Young specimens of P. magna are suggestive of P. catawbensis but have
rounded sides and a more broadly rounded anterior margin.

The interior of P. magna is also quite distinctive. The adductor track in the

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 971

delthyrial cavity is often very strongly elevated, and a small median ridge extends
anteriorly from it. The brachiophores of the brachial valve are unusually long,
and some of them show crura extending from the anterior end on the side near-
est the brachial valve.

PAURORTHIS PARVA (Pander)
Plate 151, D, figure 19

The brachial interior of the European species is introduced for comparison
with American shells. This is the type species of the genus.

Figured specimen.—52314h.

Horizon and locality—Walchow formation (BII), in Russia: Near Len-
ingrad.

PAURORTHIS PONDEROSA Cooper, new species
Plate 146, E, figures 39-43; plate 149, G, figures 44-53; plate 151, F, figures 25-29

Large for the genus, thick shelled, subcircular in outline; greatest width at the
middle; cardinal extremities rounded; sides gently rounded; anterior margin
somewhat narrowly rounded. Anterior commissure broadly and moderately
deeply sulcate. Hinge width one-third less than the midwidth. Surface fascico-
stellate, the fascicles best developed in the younger stages, flattening and dissolv-
ing near the anterior margin. .

Pedicle valve moderately convex in lateral profile, with the greatest convexity
just anterior to the umbo; anterior profile strongly and somewhat narrowly con-
vex and with long, steep lateral slopes. Pedicle valve deeper than the brachial
valve. Beak long and incurved; interarea gently apsacline, curved. Umbonal
and median regions narrowly swollen to form a fold with steep sides.

Brachial valve in lateral profile most convex in the posterior two-thirds, some-
what flattened in the anterior third. Anterior profile moderately and broadly
convex and with a slight median depression. Umbonal region strongly swollen;
beak prominent. Sulcus originating at the beak, shallow throughout its extent.
Flanks gently inflated; slopes to the margins short, moderately steep.

Interior of pedicle valve with deep and wide delthyrial cavity, deeply im-
pressed vascula media separated by a narrow and low median ridge. Brachial
interior with narrow and shallow notothyrial cavity and short, stout brachio-
phores.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
TAGIGEVOR, sitiie wndtenttts GeOhD. Haida ses jes 13.7 12.4 13.6 10,2 9.3
Paratype: ‘((1r7206a) 2348) ts Uy 7, 11.2 12.3 9.1 6.8
Fs Gr17204b)-cwiiwils. usoateiaoct 12.2 bitea! II.9 0.9 7.4
* (pedicle valve 117295a)..... 15.3 ? 15.7 BOW 910.7,
= (brachial valve 117295b).... ? 15.1 15.6 10.2 3.6

Types.—Holotype: 117294a; figured paratypes: 117293, 117294b, 117295a,b,
117296a ; unfigured paratypes: 117296b.
Horizon and locality—Sevier formation (near base) in Tennessee: On the

972 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

east side of the road 0.2 mile north-northwest of Gooseneck, Louisville (T.V.A,
138-SE) Quadrangle.

Benbolt formation in Virginia: At Rye Cove, Clinchport (T.V.A. 188-NW)
Quadrangle; 0.2 mile south of the middle fork of Moccasin Creek, 15 miles due
south of Hansonville, Hansonville (T.V.A. 205-SW) Quadrangle; 4 mile east
of Speers Ferry, Clinchport (T.V.A. 188-NW) Quadrangle; south side of
Moccasin Creek, 1.2 miles east-northeast of Willow Spring, Hansonville (T.V.A.
205-SW) Quadrangle; west slope of hill 4 mile east of Cedar Point School, Hil-
ton (T.V.A. 197-NW) Quadrangle; south side of Mount Hagan School, Hilton
(T.V.A. 197-NW) Quadrangle; east bank of sinkhole 300 feet south of Lake-
view Church on Virginia Highway 71, southwest quarter east central subquad.,
Moll Creek (T.V.A. 196-SE) Quadrangle; on Virginia Highway 74, 53 miles
east-northeast of the junction with U. S. Highway 54 (= Virginia Highway 71),
Hilton (T.V.A. 197-NW) Quadrangle.

Shippensburg formation (Pinesburg member-Echinosphaerites zone) in
Maryland: On U. S. Highway 40 on the west side of Conococheague Creek,
7 miles west of Hagerstown, Williamsport (15’) Quadrangle.

Discussion—This is the largest species of this genus in the eastern United
States. It is characterized by thick shells having a nearly circular outline or
somewhat longer than wide. The fasciculation is strong but fine. The species
differs from P. magna, the only other Paurorthis approaching P. ponderosa in
size, by its stronger fasciculation, more circular form, and thick shells. Young
specimens are also robust and subcircular. They are suggestive of P. catawbensis
but are more robust.

PAURORTHIS SPINOSA Cooper, new species
Plate 151, E, figures 20-24

Shell of about medium size for the genus, slightly wider than long, with
rounded sides and anterior margin. Hinge narrower than the greatest shell
width which is at the middle ; anterior commissure sulcate. Fascicostellate, fasci-
cles narrow, generally consisting of 2 to 3 costellae. Costellae in median and
anteromedian areas with short, spiny projections.

Pedicle valve fairly evenly and strongly convex in lateral profile; anterior
profile somewhat narrowly convex in the median region but with long, moder-
ately steep slopes. Beak strongly incurved; interarea gently apsacline, strongly
curved. Umbo narrowly swollen, the swelling passing anteriorly into the inflated
median region. Flanks slightly convex in profile, moderately steeply inclined.

Brachial valve fairly evenly and gently convex in lateral profile; anterior pro-
file broadly and gently convex. Beak prominent, umbo swollen. Sulcus origi-
nating at the beak, narrow and fairly deep at its place of origin but becoming
wider and shallower anteriorly. Flanks moderately and narrowly swollen; lat-
eral slopes short and moderately steep.

Measurements in mm.—Holotype, length 8.5, brachial length 7.7, width 9.2,
hinge width 7.0, thickness 5.4.

PARTI CHAZYAN AND RELATED BRACHIOPODS—COOPER 973

Type.—Holotype: 117297.

Horizon and locality Edinburg formation (about middle of Nidulites zone)
in Virginia: On Tumbling Run, 14 miles southwest of Strasburg, Strasburg
(15’) Quadrangle.

Discussion.—This is a small shell but a distinctive one. It is characterized by
somewhat distant costellae which form indistinct and narrow fascicles. The pedi-
cle valve is somewhat narrowly convex in anterior profile, and the sulcus on the
brachial valve is deep. It differs from P. catawbensis in ornamentation and form;
it differs from P. fasciculata and P. fascifera in its more distant costellae and
finer fascicles ; it is not parallel sided like P. longa, and it differs from young
forms of P. magna and ponderosa in its distant costellae and lesser fasciculation.
It has a strong development of short, spiny projections particularly on the
brachial valve. These were seen in other species but not in the degree to which
they are developed on this one.

PAURORTHIS sp. 1
Plate 150, C, figures 25-37

Shell of about medium size for the genus, subcircular in outline; relation of
length and width variable, some specimens having width greater than length and
vice versa. Greatest width at about the middle; margins strongly rounded; an-
terior commissure gently sulcate. Surface fascicostellate; fascicles narrow, nu-
merous, and consisting of 3 or 4 costellae.

Pedicle valve unevenly convex in lateral profile, with the maximum curvature
just anterior to the umbo; anterior profile narrowly convex and with steep lat-
teral slopes. Beak long; interarea curved, gently apsacline. Umbo swollen;
median area just posterior to middle strongly swollen. Anterior moderately
swollen ; lateral slopes flat and steep.

Brachial valve with maximum convexity just posterior to the middle; anterior
profile broadly convex and with the median region slightly indented by the sul-
cus. Beak prominent, umbo moderately swollen; sulcus originating at the beak,
shallow and wide, merging anteriorly into the flattened anterior. Sulcus occupied
anteriorly by 3 to 5 fascicles. Hanks gently swollen; lateral slopes steep.

Interior of pedicle valve with deep notothyrial cavity; dental plates obsolete.
Vascula media prominent and separated anteriorly by a short, low thickening of
the floor ; diductor scars usually distinct, elongate, but often not impressed in old
and thick shells.

Brachial interior with thin cardinal process, thick brachiophores, and low
median ridge. Adductor field deeply impressed, elongate.

Measurements in mm.—1172992, length 9.8, brachial length 8.5, width 10.5,
hinge width 7.4, thickness 5.7.

Figured specimens.—117298a-e, 117299a.

Horizon and locality—Basal Athens formation in Tennessee: 600 feet S. 40°
E. of the railroad crossing 1 mile northeast of the courthouse in Athens, Athens
(T.V.A. 125-NE) Quadrangle; roadside just east of intersection 24 miles south-
southeast of Riceville, Calhoun (T.V.A. 125-SW) Quadrangle.

974 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion.—The specimens described above suggest P. longa and P. fascicu-
lata. They differ from the former in not having the strongly parallel sides and
from the latter in not being so strongly fasciculate. They are nearer the latter,
however.

PAURORTHIS sp. 2
Plate 151, B, figures 7-11

Shell of about medium size, wider than long with narrowly rounded cardinal
extremities, nearly straight sides and broadly rounded anterior margin. Anterior
commissure somewhat narrowly sulcate. Surface fascicostellate, fascicles
crowded, consisting generally of 2 or 3 costellae.

Pedicle valve moderately convex in lateral profile and with the greatest curva-
ture just anterior to the umbo; anterior profile narrowly convex in the middle,
with long and moderately steep lateral slopes. Beak long, strongly incurved;
interarea short, apsacline. Umbo subcarinate, the carination continued anteriorly
as an indistinct fold nearly to the front margin. Lateral slopes slightly convex.

Brachial valve gently and evenly convex in lateral profile; anterior profile
gently and broadly convex and with the median region slightly depressed. Sul-
cus originating at the beak, moderately deep and wide at the anterior margin.
Flanks gently swollen; lateral slopes fairly long and gentle. |

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
RI AOsast peg ibe lehitela. y 8.0 7.4 9.0 m2 4.7
TEGZOS enc a os isla iates 7.6 7.2 9.0 a2 4.3

Figured specimen.—117302a; unfigured specimen: 117302b.

Horizon and locality—Lower part of Sevier formation in Tennessee: 4 mile
northeast of Miser, Louisville (T.V.A. 138-SE) Quadrangle.

Discussion.—These shells suggest P. catawbensis in outline and the somewhat
shouldered character of the posterior half. They are, however, more deeply sul-
cate and have a more erect beak.

CYCLOMYONIA Cooper, new genus

(Greek kyklas, circle; mys, muscle)

Shell small, dalmanellid in outline and profile; pedicle valve deeper than the
brachial valve. Anterior commissure gently sulcate. Surface finely costellate, the
costellae not markedly fasciculate. Punctate.

Pedicle interior with small, long teeth ; dental plates fairly strong, receding and
forming a rim to the muscle area. Delthyrial cavity deep, generally with the floor
thickened and occupied by a wide adductor track; diductor scars small and nar-
row. Anterior to delthyrial cavity floor of valve occupied by a short, elevated
callosity. Vascula media strong, located on each side of callosity.

Brachial valve like Paurorthis with small notothyrial chamber occupied by a
simple cardinal process; fairly long brachiophores. Median ridge long and nar-
row. Adductor field somewhat shield shaped, the posterior adductors lying out-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 975

side the elongate anterior pair which is located on each side of the median
ridge.

Genotype—Cyclomyonia peculiaris Cooper, new species.

Discussion—This genus strongly resembles Paurorthis in its external form
and brachial interior but differs in ornamentation, the small teeth of the pedicle
valve, the strong callosity anterior to the pedicle muscle area, and the greater
development of the dental plates.

This genus was individualized because of the peculiarities of the interior of
the pedicle valve and variations of the exterior from typical Paurorthis. The
ornamentation of Cyclomyonia is more even and is not so strongly fasciculate as
that of Paurorthis. Inside the brachial valve the apex is marked in some speci-
mens by a thickening in the form of a narrow fold bent toward the floor and
leaving a crease in the middle. This is like a thickening seen in other punctate
shells.

The teeth are long and slender and quite suggestive of Laticrura. The dental
plates are of the receding type, forming a rim along the delthyrial edge and the
side of the delthyrial cavity. These swing toward the floor and unite with the
marked callosity anterior to the delthyrial cavity. This callosity is not like the
thickening seen in Paurorthis which is usually a long, slender ridge extending
nearly to the anterior margin. In some specimens of Cyclomyonia the vascula
media are curved at the anterolateral extremity of the callosity.

CYCLOMYONIA PECULIARIS Cooper, new species
Plate 146, F, figures 44-61

Shells approaching 4 inch in width, wider than long; sides and anterior mar-
gin rounded; greatest width at about the middle. Surface marked by fine cos-
tellae, about 5 to the millimeter at the anterior margin.

Pedicle valve deeper than the brachial valve and having a moderately strongly
convex lateral profile; anterior profile somewhat narrowly convex in the median
region and with long, steep lateral slopes. Interarea long, strongly apsacline;
beak incurved. Umbo swollen and subcarinate, the swelling continued anteriorly
at least to the middle where it merges into the general convexity. Median
region swollen; flanks gently convex.

Brachial valve most convex in the posterior third when seen in lateral pro-
file; anterior profile gently and broadly convex but with a median depression.
Sulcus originating at the beak, shallow, but with the median line deepest. Flanks
somewhat swollen.

Measurements in mm.—Holotype, length 7.8, width 9.2, hinge width 7.6,
thickness 3.0.

Types.—Holotype: 117300c; figured paratypes: 117300a,b,d-j.

Horizon and locality.—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—No other species of this genus is now known to which this species
can be compared.

976 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Family HETERORTHIDAE Schuchert and Cooper, 1931

Subfamily HARKNESSELLINAE Bancroft, 1928

Biconvex, fascicostellate Heterorthidae having a prominent fold on the pedicle
valve and a corresponding sulcus on the brachial valve.

Genus REUSCHELLA Bancroft, 1928

Reuschella BANcRort, Mem. Manchester Lit. Phil. Soc., vol. 72, p. 180, 1928—SCHUCHERT
and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. I, p. 139, 1932.

This genus embraces large shells externally fascicostellate and with endopune-
tate shell structure. The pedicle valve generally bears a prominent median fold
and the brachial valve is strongly sulcate. The valves are subequally convex.
Inside the pedicle valve the muscle field is small with the adductor field occupying
a shallow depression and the diductor tracks located on each side of it. The den-
tal plates are generally short but stout. Inside the brachial valve the brachio-
phores are short and stout and are supported by swelling of shell substance
along their inner surfaces. The cardinal process has a short shaft borne on the
swelling that clogs the notothyrial cavity; the myophore is small and trilobate.
The median ridge is short and low.

This genus is fairly common in the Middle Ordovician of England and Wales
but has hitherto not been reported on this continent. It proves now to be com-
mon in the Oranda formation in Virginia and is known from the Trenton (Sher-
man Fall) in Vermont. A species has been identified in the Jacksonburg forma-
tion of New Jersey, and another is known from dark shales under the Eureka
quartzite in Nevada.

REUSCHELLA AMERICANA Cooper, new species
Plate 147, A, figures 1-7; plate 147, B, figures 8-20
Dalmanella edsoni BASSLER (part), Cambrian and Ordovician: Maryland Geol. Surv., p. 243,

pl. 49, figs. 17-19 (not 20 and 21), 1919.—Coorer and Cooper, Bull. Geol. Soc. Amer.,
vol. 57, pl. 3, figs. 33, 34, 1946.

Shell large, rectangular in outline with the width slightly greater than the
length. Cardinal extremities varying from acute to obtuse; lateral margins
slightly concave to gently rounded ; anterolateral extremities somewhat narrowly
rounded; anterior margin truncated. Anterior commissure rectimarginate to
sulcate. Surface fascicostellate with 5 or 6 well-defined fascicles on each side of
the fold. Fold consisting of 3 fascicles, a median one and one on each side of it.
Costellae appearing in 4 generations by bifurcation and intercalation; 7 to 10
costellae may be counted in 5 mm. at the front margin.

Pedicle valve gently convex in lateral profile with the greatest convexity in
the posterior half. Fold originating at the beak where it is very narrowly rounded
and generally smooth, widening gradually anteriorly and heightening to about
the middle from which it gradually declines in height to the front margin. Fold
scarcely distinguishable at the front margin of some specimens except for the

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 977

bundling of costellae. Lateral slopes of fold steep; flanks bounding fold flattened
or gently concave, becoming gently convex in a posterolateral direction where
the areas just anterior to the cardinal extremities are gently convex. Slopes to
cardinal extremities gentle. Interarea short, apsacline.

Brachial valve very gently convex with the greatest convexity in the posterior
half ; about as deep as the pedicle valve. Sulcus narrow and deep in the posterior
third, becoming wider and shallower anteriorly to the front margin where it
occupies about one-quarter the valve width. Folds bounding sulcus strongest in
the posterior, becoming flatter anteriorly and almost disappearing along the an-
terolateral margin. Slopes to lateral margins gentle.

Pedicle interior having small muscle field with width about equal to length;
teeth small; dental plates short, stout. Median ridge inside the brachial valve
heightened by the exterior sulcation which is most prominent at the posterior.
Notothyrial cavity much restricted by secondary shell built on the inner sides
of the short brachiophores; cardinal process short and stout.

Measurements in mm.—
Hinge Thick-

Length Width width ness

TOG EY ME a aici eee teal voc steestnuein ane orerarel troyorex ee SLO 31.8 32.3 ?
Paratype (pedicle valve 110840m) ....... 13:3 17.8 17.3 ?
oe Cress es WETOSAOE) he rerreteere 21.8 28.4 28.7 ?

i uit St ULOSAC Aer ers ciate 27 Bg 27.3 Re

n (brachial valve 110840k)....... 12.8 16.5 & ?

z Ga? <: SeARROBAGH))i sites ieic 21.4 28.8 25.0? ?

s (Cobie *) SETO840f)! + saeee 225.5 34.1 28.6 ?

Types——Holotype: 110840b; figured paratypes: 110840a,c-g,i,w; unfigured
paratypes: 110840h,j-v; figured specimens: 117346a-e.

Horizon and locality Oranda formation in Virginia: 0.6 mile northwest of
Linville Station; just west of the junction of Virginia County Highways 617=
gio, and 777 about 4 mile north of Green Mount Church, Broadway (15’)
Quadrangle.

Bowman Farm, south side of U. S. Highway 11, 1 mile southwest of Wood-
stock, Edinburg (15’) Quadrangle; Cedar Grove Church, 200 yards on Virginia
County Road 616, 3.5 miles southwest of Mount Jackson, Mount Jackson (15')
Quadrangle; on U. S. Highway 11, 14 to 2 miles southwest of Strasburg, Stras-
burg (15’) Quadrangle; 3 miles north of Long Glade=Spring Hill, Parnassus
(15’) Quadrangle.

Same formation in Pennsylvania: 1 mile south of St. Thomas, Mercersburg
(15’) Quadrangle.

Jacksonburg formation in New Jersey: 14 miles south of Annandale, Hunter-
don County.

Discussion.—This species is characterized by its narrow fold and sulcus, large
size, and fasciculate exterior. It is distinguished from R. edsoni in the less promi-
nent development of the fold and sulcus.

978 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

REUSCHELLA EDSONI (Bassler)
Plate 148, D, figures 27-29

Dalmanella edsoni BASSLER, Cambrian and Ordovician: Maryland Geol. Surv., p. 243, pl. 49,
figs. 20, 21 (not 17-19 = Reuschella americana Ulrich and Cooper), 1919.—Kay, Bull.
Geol. Soc. Amer., vol. 48, p. 302, pl. 10, 1937.

Large, slightly wider than long, cardinal extremities acute or obtuse depend-
ing on width of hinge; lateral margins gently rounded; front margin truncated.
Anterior commissure strongly sulcate. Surface fascicostellate.

Pedicle valve marked by a prominent subcarinate median fold that increases
in height to the middle or slightly anterior to the middle, after which it slopes to
the anterior margin. Slopes flanking fold long and moderately steep. Areas
bounding fold gently convex. Inside the pedicle valve the muscle field is fairly
large, in length about equal to one-tenth the length of the valve. Width of muscle
field about equal to its length. Diductor scars large.

Brachial valve gently convex in lateral profile, with the greatest convexity at
about the middle. Sulcus prominent, widening and deepening anteriorly to the
front margin where it occupies slightly more than a third of the width of the
valve. Folds bounding sulcus gently convex with gentle slopes to the cardinal
and lateral margins. Interior unknown.

Measurements in mm.—

Hinge

Length Width width
Tsectotype «(pedicle -valvee) »\« oj. ais « s::0/<:0,0)0/<es 24.9 20.4 34.0
Paratype (brachial valve 66169b).......... 21.0 27.9 20.6 ?

Types.—Lectotype: 66169d; figured paratypes: 66169b,c; unfigured paratype:
661692, e.

Horizon and locality—Trenton group (Sherman Fall formation) in Vermont:
Shipyard Bay, Highgate Springs, St. Albans (15’) Quadrangle.

Discussion—This species is distinguished by the strong fold continuous from
beak to anterior margin and the consequent deep and wide sulcus in the brachial
valve. It differs from R. americana in the greater strength of the fold and sulcus.

In defining this species Bassler used 7 specimens, 2 of which came from
Pennsylvania and 5 from Vermont. The lot from Pennsylvania consists of
3 pieces representing 2 specimens. Figures 17 and 19 of plate 49 in the Mary-
land volume represent counterparts of the same specimen. It is here recom-
mended that the Pennsylvania specimens be excluded from the species because
they have characters different from those of the Vermont specimens and are here
called R. americana. Inasmuch as Bassler intended to honor George E. Edson
of St. Albans, Vt., one of the Vermont specimens should be selected as type
specimen. Specimen 66169d is selected from Bassler’s cotype lot from Highgate
Springs, Vt. Although this specimen was not figured by Bassler, it is the most
complete of the lot and shows best the specific characters emphasized herein.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 979

REUSCHELLA VESPERTINA Cooper, new species
Plate 186, C, figures 11, 12; plate 260, B, figures 6-10

Shell of medium size for the genus, wider than long, rectangular in outline;
hinge slightly narrower than the midwidth; sides slightly oblique; anterolateral
extremities narrowly rounded; anterior margin broadly rounded ; anterior com-
missure strongly sulcate; costellae numbering Io to 12 in 5 mm. at the anterior
margin of a large specimen.

Pedicle valve gently concave in lateral profile, flat or gently concave in an-
terior profile; umbo narrowly convex to carinate and extended anteriorly to the
front margin as a strong, narrow fold. Flanks bounding fold flat to concave;
sides deflected strongly in the direction of the pedicle valve. Interarea apsacline,
moderately long.

Brachial valve gently convex in lateral profile and broadly convex in anterior
profile but with the sides steep. Umbo and medial region deeply sulcate, the
sulcus extending to the anterior margin. Flanks bounding sulcus narrowly
rounded, slopes of flanks steep; posterolateral extremities deflected toward the
brachial valve.

Interior unknown.

Measurements in mm.—Holotype, length 21.2, length of brachial valve 21.7,
midwidth 27.2, hinge width 27.0, thickness 6.4.

Types.—Holotype: 124230a; figured paratypes: 123255b,c; 124230b; un-
figured paratype: 123255a.

Horizon and locality.—Upper part of the dark shale under the Eureka quart-
zite in Nevada: Under two knobs of Eureka quartzite, north side of canyon,
3.1 miles N. 32° E. of the Blair (Segura) Ranch, Antelope Mountains; on the
north-facing nose of hill 8167, Martins Ridge, Monitor Range, Roberts Moun-
tains (1°) Quadrangle.

Discussion.—This species is characterized by the prominence of its fold and
sulcus and the strongly deflected sides and posterolateral extremities. It differs
from R. americana in not attaining the great size of that species, in having a
broader fold and sulcus and more subdued costellae. This species is common
in the upper part of the dark shales below the Eureka quartzite, but well-
preserved specimens are rare.

Family LINOPORELLIDAE Schuchert and Cooper, 1931

Dalmanellacea having a cruralium in the brachial vave.

LATICRURA Cooper, new genus

(Latin latus, wide; crus, leg)

Shells pionodemoid in outline and profile; with a long interarea, and open
delthyrium. Anterior commissure sulcate. Surface multicostellate, with scat-
tered, swollen, and hollow costellae as in Pionodema. Shell punctate.

Inside the pedicle valve the dental plates are well developed, slender, receding.
The anterior ends of the dental plates are continued along the floor of the valve

980 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

as low ridges bounding the muscle area. Pedicle attached to a smail apical plate
fixed on the sides of the dental plates at the apex. Muscle area elongate, with
elongate and narrow diductor scars. Adductor track narrow, not elevated.

Brachial valve with a deep notothyrial cavity formed by the convergence of
the brachiophore plates to unite with the median septum. Brachiophores long
and broad, grooved on the outside and forming an inverted S in section. Median
ridge strong and high. Cardinal process a low and simple ridge on the floor of
the notothyrial cavity.

Genotype.—Laticrura pionodema Cooper, new species.

Discussion—tThis genus is best characterized by a combination of exterior
and interior features. The known species all have an elongate beak and a long
interarea with long, narrow delthyrium. The surface is marked by costellae, usu-
ally not brought into fasciculae. Isolated swollen and hollow costellae as in
Pionodema are often present, and one species was individualized on the strength
of their development.

Inside the pedicle valve the strong, receding dental plates are distinctive. The
anterior ends of the plates are usually continued anteriorly to the front end of
the muscle scars. The teeth are small but have deep fossettes. In some speci-
mens, particularly of L. latibrachiata, a small plate appears in the apex of the
delthyrium. This plate is short and is located on the sides of the dental plates
between the floor of the delthyrial cavity and the surface of the delthyrium.

The most distinctive feature of the brachial valve is the large brachiophore
with its great length and width. This is anchored to the median ridge by con-
verging brachiophore supporting plates. These form a narrow notothyrial cavity
not unlike that of Scaphorthis and Corineorthis among the impunctate genera
and Linoporeila of the punctate genera. The cardinal process is a thin, simple
blade on the floor of the notothyrial cavity. No other punctate genus is similar
to this one in interior details, the brachiophores being unique. Linoporella is
similar in the form of the notothyrial cavity but is externally different and is
not provided with the enormous brachiophores.

LATICRURA HETEROPLEURA Cooper, new species
Plate 143, F, figures 25-29; plate 221, A, figures 1-6

Large for the genus, wider than long, subrectangular in outline; hinge not
quite equal to widest part which is at about the middle; sides gently rounded ;
anterolateral extremities narrowly rounded; anterior margin broadly rounded;
anterior commissure sulcate ; surface costellate, costellae numbering about 4 or 5
to the millimeter at the front margin; surface marked also by numerous swollen
and enlarged costellae.

Pedicle valve with elongate and erect beak; umbo swollen, narrow; lateral
profile gently convex; anterior profile narrowly convex in the median region but
with long and moderately steep lateral slopes; middle narrowly convex and
forming a poorly defined fold. Flanks slightly convex.

Brachial valve unevenly convex in lateral profile, the posterior half gently con-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 981

vex, the anterior half moderately bent toward the pedicle valve; beak well de-
fined, protruding posterior to the posterior margin ; umbo swollen, sulcate ; sulcus
deep and narrow; forming a short tongue at its anterior end. Flanks swollen
with moderate slopes to the lateral margins and medianly to the sulcus.

Measurements in mm.—Holotype, length 8.9, brachial length 7.6, width 10.2,
hinge width 8.8, thickness 5.9.

Types.—Holotype: 117263a; figured paratype: 117263d; unfigured paratypes:
117263b,c,e.

Horizon and locality.—Little Oak formation in Alabama: At the junction of
the Bailey Gap and Cahaba Valley roads, SW4SW3 sec. 13, T. 19 S., R. 2 W.,
1? miles northeast of Newhope Church, Vandiver (15’) Quadrangle; cut on
U. S. Highway 31, 4 mile north of Pelham, Bessemer Iron District (15’)
Quadrangle.

Discussion.—This species is distinguished from the others described herein
by the great development of swollen and hollow costellae on the exterior. It has
a deeper and more pronounced sulcus in the brachial valve than that of L. piono-
dema. It is closest to L. latibrachiata but differs in ornamentation and in a more
erect and incurved beak.

LATICRURA LATIBRACHIATA Cooper, new species
Plate 143, E, figures 19-24; plate 145, A, figures 1-13; plate 149, B, figures 4-9

Shell subcircular in outline, with the length and width about equal. Hinge
narrower than the greatest width which is near the middle. Lateral margins
rounded; front margin broadly rounded to slightly emarginate at the middle.
Anterior commissure sulcate. Surface multicostellate, with about 4 costellae in
the space of I mm. at the front margin.

Pedicle valve gently convex in lateral profile; somewhat carinate in anterior
profile. Middle of valve from the beak to the anterior margin swollen a little
to form a low and poorly defined fold which is also responsible for the slight
emargination of the front. Lateral slopes from the fold to the margins steep.
Interarea elongate, curved; beak strongly incurved, narrow and sharp.

Brachial valve nearly equal to the pedicle valve in depth, moderately convex
in lateral profile, lobate in anterior profile. Sulcus, shallow and narrow, origi-
nating at the umbo and extending to the front margin where the valve is ex-
tended slightly to form a short but inconspicuous tongue. Flanks swollen with
fairly steep slopes to the sulcus and the lateral margins. Lateral slopes steepest
toward the cardinal extremities ; slopes to the sulcus short and steep. Interarea
long for this structure on a brachial valve.

Interior of the pedicle valve characterized by good development of the apical
plate, and the brachial valve by the ponderous development of the brachiophores.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness

TPOIOLVDE wie siecle cnc s ts 8.9 8.1 9.6 8.0 6.6
Paratype (117265p)..... 8.0 7.5 0.5 7 | 5.0

982 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Types.—Holotype: 118041a; figured paratypes: 117264a-c, 117265a,b,d,f,
h,k,p; unfigured paratypes: 117265¢,e,g,i,j,l-0,q, 117266a-h.

Horizon and locality.—Arline formation (lower-middle) in Concord (T.V.A.
138-SW) Quadrangle, Tennessee: In glade + mile southeast of Friendsville;
100 yards southwest of the Negro Cemetery, 4 mile northeast of Friendsville.

Discussion.—Fine silicified specimens of this species occur at Friendsville. Al-
though the silicification is coarser than that of some of the other genera at this
place, it is sufficiently good to yield excellent study material. The important
specific characters are the ornamentation, well-developed sulcus which originates
at the umbo, the well-developed apical plate, and the ponderous cardinalia. The
ornamentation is stronger than that of L. pionodema, the apical plate is better
developed, and the cardinalia more robust.

LATICRURA MAGNA Cooper, new species
Plate 144, B, figures 26-29; plate 145, C, figures 20-23

Shell large, subcircular in outline, with the greatest width at the middle; hinge
narrower than the greatest width; sides and anterior margin broadly rounded;
costellae fine and crowded, appearing in several generations, about 4 to the milli-
meter at the anterior margin of the holotype.

Pedicle valve most convex in the umbonal region when seen in lateral view;
anterior portion somewhat flattened. Anterior profile with median region nar-
rowly rounded and with long, fairly gentle slopes to the margins. Interarea
strongly apsacline, beak short and slightly incurved.

Brachial valve most convex at the umbo in lateral profile; broadly convex in
anterior profile. Beak prominent; umbo swollen; sulcus originating at the beak,
narrow and shallow and extending to the anterior margin. Flanks gently swollen.

Measurements in mm.—Holotype, length 10.5, brachial length 10.0, width
13.7, hinge width 11.0, thickness ?.

Types.—Holotype: 117267a; figured paratypes: 117267b, 117268a; unfigured
paratypes: 117267c, 117268b,c.

Horizon and locality—Oranda formation in Virginia: 0.6 mile northwest of
Linville, Broadway (15’) Quadrangle. On the railroad 4 mile west of Strasburg ;
Lee Highway (U. S. 11), 14 miles southwest of Strasburg; Strasburg (15’)
Quadrangle.

Same formation in Pennsylvania: 1 mile north of Guilford Springs, Chambers-
burg (15’) Quadrangle.

Martinsburg formation (part with Brongniartella=Salona) in Virginia: On
Virginia Highway 617=910, 0.15 mile north of Green Mount Church, Broadway
(15’) Quadrangle.

Discussion.—This species is distinguished from the others herein described
by its much greater size, and its strongly apsacline, almost procline interarea,
slightly incurved beak, and sides sloping rapidly toward the middle. The species
is a rare shell at all localities where it has been seen.

PART, 0 CHAZYAN AND RELATED BRACHIOPODS—COOPER 983

LATICRURA PIONODEMA Cooper, new species
Plate 144, A, figures 1-25; plate 144, C, figures 30-33; plate 145, B, figures 14-19;
plate 146, A, figures 1-4

Shell of about the same size as L. latibrachiata, about as wide as long; cardi-
nal extremities well rounded; lateral margins very slightly curved; anterior
margin narrowly rounded. Anterior commissure moderately sulcate. Surface
finely multicostellate, with 5 costellae in 1 mm. at the front margin of the
holotype. }

Pedicle valve moderately convex in lateral profile, with the umbo forming the
most convex part. Anterior margin narrowly rounded. Fold low and inconspicu-
ous; slopes to the lateral margins steep. Interarea long, strongly curved; beak
sharp and strongly incurved. Delthyrium narrow.

Brachial valve moderately convex in lateral profile, slightly shallower than the
pedicle valve. Anterior third subgeniculate and protruding slightly to form a
short tongue. Sulcus broad and shallow, originating at the umbo. Flanks slightly
swollen. Slopes to cardinal extremities fairly steep; lateral slopes moderately
inclined. Interarea moderately long, beak incurved.

Measurements in mm.—Holotype, length 11.4, dorsal length 10.3, width 11.0,
hinge width 8.0, thickness 6.0.

Types.—Holotype: 1172721; figured paratypes: 117269¢,g,i,k,l, 117270a,b,d,
117271b,g, 117272e¢,g, 117273, 117274a,b; unfigured paratypes: 11726g9a-d,f,h,
j,m,n, 117270¢,e-g, 117271a,c-f, 117272a-d,f,h, 117274¢,d.

Horizon and locality —Effna-Rich Valley formations in Virginia: At Porter-
field Quarry, 5 miles east of Saltville, Maccrady (T.V.A. 218-NW) Quadrangle.

Edinburg formation (base of Liberty Hall facies) in Virginia: 1.8 miles S. 4°
W. of Bethel Church, 5.9 miles east of Harrisonburg, Harrisonburg (15’)
Quadrangle.

Edinburg formation (Cyrtonotella zone) in Virginia: Just above quarry § mile
northeast of Strasburg Junction, Strasburg (15’) Quadrangle.

Pratt Ferry formation in Alabama: 0.2 miles southeast of Pratt Ferry, Blocton
(15’) Quadrangle.

Discussion.—This species is characterized by its rotund form, its fine, even
costellae, lack of an apical plate, and broad, shallow sulcus on the brachial valve.
It is most like L. latibrachiata but differs in having a broader and shallower sul-
cus and in lacking a deltidial plate. It also possesses a more erect beak than the
Friendsville species.

ELASMOTHYRIS Cooper, new genus

(Greek elasmo, plate; thyris, opening)

Shell small, biconvex with deep valves, the pedicle valve being the deeper ; out-
line subrectangular ; sides and anterior rounded; hinge wide but less than the
midwidth ; anterior commissure sulcate. Pedicle interarea long, delthyrium open ;
surface multicostellate. Shell interarea long, delthyrium open; surface multicos-
tellate. Shell substance punctate.

984. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle interior with long, slender teeth and deep delthyrial cavity; dental
plates receding, flaring laterally and attached to the sides; muscles attached to
a thin horizontal plate laid across the delthyrial cavity at the base of the dental
plates and attached to the sides of the valve to leave a deep delthyrial chamber
between the plate and the valve floor. Muscle scars well impressed on plate;
adjustor-diductor scars located at base of dental plates; adductor (?) scars
broad, occupying median region and separated from other scars by low ridges.

Brachial valve with small, deep sockets defined by a fulcral plate; notothyrial
cavity formed by brachiophore plates uniting with a median septum and the
valve floor; brachiophores long and slender ; cardinal process located at the end
of a low septum occupying the floor of the notothyrial chamber and with a bul-
bous myophore; median septum thin, elevated anteriorly but not reaching the
front margin.

Genotype.—Elasmothyris concinnula Cooper, new species.

Discussion.—This interesting little shell is characterized externally by con-
siderable depth in both valves, costellate ornamentation, and a general resem-
blance to Skenidioides. The interior, however, is marked by normal dental plates
and a horizontal muscle plate in the pedicle valve, and a notothyrial chamber and
long, slender brachiophores in the brachial valve. Besides these features the
shell substance is punctate.

Several characters of this peculiar genus need explanation. The determination
of the presence of punctae rests on observation of silicified shells. This is not
ordinarily a type of preservation that yields good evidence of these important
structures, but in this instance nearly every specimen shows small black spots
on both sides of the shell, some of which are radially arranged. These are taken
to be fillings of punctae by mud, pyrite, or other impurity. Confirmation of the
punctate condition is to be seen also in the structures of the brachial valve which
are discussed below. The absence of a deltidium in such an early brachiopod is
negative evidence.

The pedicle valve is characterized by strong, sharp teeth buttressed by reced-
ing dental plates which flare laterally and are attached to the sides of the valve.
The plates are normal in every respect, but at their base a plate is built hori-
zontally across the delthyrial chamber. This plate divides the delthyrial cavity
into an upper and lower chamber. The plate is also marked by 2 oblique ridges
that clearly indicate the position of muscle scars.

At the base of the dental plates is an elongate, tear-shaped scar than can be
interpreted in two ways: it is the adjustor scar which is usually found in that
situation, or it is a scar of the diductor and adjustor muscles with no evidence
left on the shell by which the individual scars may be differentiated. On this in-
terpretation the adductor field is fairly large but no individual scars can be differ-
entiated. The horizontal plate is somewhat variable in form. In some specimens
it is horizontal and nearly flat. In others it is bowed medially in the direction of
the brachial valve. This plate sets Elasmothyris quite apart from any of the other
skenidioid shells such as Skenidioides, Tropidothyris, or Skenidium.

The brachial valve of Elasmothyris suggests that of the punctate shell Lino-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 985

porella in the form of its cardinal process and notothyrial chamber. It is frequent
in punctate shells for the median septum to be continued posteriorly along the
floor of the notothyrial chamber and unite with the shaft of the cardinal process.
Such is the case in Elasmothyris, and the brachial structures are in support of
the idea that the shell is punctate. Specimens of Elasmothyris are very small
and not always well preserved, but the cardinal process appears to have a bulbous
or expanded myophore such as that of Linoporella or other dalmanelloid brachio-
pods. The latter feature and the posterior continuation of the median septum
differentiate Elasmothyris from the other skenidioid genera mentioned above.

ELASMOTHYRIS CONCINNULA Cooper, new species
Plate go, F, figures 35-42

Shell minute, wider than long and with the hinge less than the midwidth;
sides gently rounded; anterior margin broadly rounded to truncated; anterior
commissure strongly sulcate. Surface costellate, costellae increasing by inter-
calation ; anteriorly somewhat fascicostellate.

Pedicle valve moderately convex in lateral profile, with the maximum con-
vexity in the posterior third; anterior profile domed and narrowed medianly.
Umbonal and median region swollen to form a low fold extending from beak to
anterior margin. Flanks on each side of fold descending steeply to the margins.
Interarea long; beak slightly incurved. Interior as described for the genus.

Brachial valve unevenly convex with the posterior somewhat flattened and the
anterior curved moderately toward the pedicle valve ; umbo gently convex; sul-
cus originating just anterior to the umbo, widening and deepening anteriorly to
the margin where a short tongue is formed. Flanks bounding sulcus moderately
swollen; posterolateral extremities deflected toward the pedicle valve and flat-
tened. Interior as described for the genus.

Measurements in mm.—Holotype, length 1.2, brachial length 1.3, midwidth
1.5, hinge width 1.3, thickness 1.0.

Types.—Holotype: 117371a; figured paratypes: 117371b-d.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—No other species of this genus is known to which this one may
be compared.

Family SCHIZOPHORIIDAE Schuchert, 1929

Dalmanellacea having lenticular or resupinate profile and fine costellae ; brach-
ial interior characterized by erect, subparallel to divergent brachiophore support-
ing plates and slender, solid brachiophores; sockets defined by fulcral plates.

Subfamily ScH1zopHoRIINAE Schuchert, 1929

Finely costellate, unplicated Schizophoriidae.

986 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genus PIONODEMA Foerste, 1912

Pionodema Foerrste, Bull. Sci. Lab., Denison Univ., vol. 17, p. 139, 1912.—CoopPeEr, Journ,
Paleont., vol. 4, pp. 369-382, 1930—SCHUCHERT and Cooper, Mem. Peabody Mus. Nat,
Hist., vol. 4, pt. 1, pp. 141-142, 1932.

PIONODEMA CAMERATA Cooper, new species
Plate 162, E, figures 24-32

Shell of moderate size for the genus, wider than long, subrectangular in out-
line; widest at about the middle; hinge narrow; sides rounded; anterior gently
rounded; surface marked by costellae that number 14 or 15 in 5 mm. at the
front of an adult shell.

Pedicle valve moderately convex in lateral profile, with the maximum curva-
ture just anterior to the umbo and the anterior half somewhat flattened ; anterior
profile broadly and fairly strongly convex ; median and umbonal regions swollen ;
flanks moderately convex but with moderate slopes to the margin. Interior with
large bilobed muscle area with somewhat elongate diductors and a long median
ridge extending anteriorly from the adductor field; region on each side of muscle
area marked by oblique, elongate ridges.

Brachial valve with lateral profile slightly more convex than that of the pedicle
valve and with the maximum convexity in the umbonal region. Anterior profile
somewhat strongly domed. Umbonal and median regions strongly swollen; an-
terior slope long and moderately steep. Flanks convex, and with short and steep
slopes. Interior with brachiophore plates swinging anteriorly to meet and form
a long V-shaped chamber. Cardinal process with long shaft and small lobate
myophore.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
ie lellcls 7) ee ? 11.4 14.2 8.0 ? 3.6 ?
Paratype (117343a)... 11.4 ? 14.5 10.2 2702
if (1173434) 00.) 10.7 Hr.2 8.8 2.0?

Types.—Holotype: 117343k; figured paratypes: 117343a-c,i,j,m,o; unfigured
paratypes: d-h,l,n,p,q.

Horizon and locality—Sevier formation (Bacon Bend member-top, just under
Bays red beds) in Tennessee: 4 mile northeast of Fourmile Church, Tallassee
(T.V.A. 139-SE) Quadrangle.

Discussion—This species is characterized by moderately strong ornamenta-
tion but more especially by the camerate arrangement of the brachiophore plates
of the brachial valve. None of the specimens, which are all preserved as impres-
sions of the interior or exterior, shows unequivocal traces of punctae. This made
it difficult to decide whether the species belongs to Pionodema or Doleroides,
because the brachial plates suggest the latter genus. It was decided that Piono-
dema is the correct genus because of the character of the pedicle muscle area
and the nature of the cardinal process.

The pedicle muscle area is like that of Pionodema rather than Doleroides be-

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 987

cause of the presence of the low median septum extending anterior to the adduc-
tor impression. The cardinal process has a thin but long shaft and is surmounted
by a small lobate myophore like that of Pionodema. The brachial plates are
flaring and like Pionodema, but they are extended anteriorly and inward to
surround the anterior end of the cardinal process shaft and thus to form a long,
partially enclosed chamber that simulates Doleroides. No other species of Piono-
dema has been seen with such a structure, although some specimens of P. subae-
quata approach it. This species is important because it occurs just under the
Bays red beds and thus helps to date the red bed series and the Sevier under
it. This Pionodema suggests an early Trenton age for the beds in which it occurs.

PIONODEMA CIRCULARIS (N. H. Winchell)
Plate 154, A, figures 1-5; plate 154, B, figures 6-11

Orthis circularis N. H. WINCHELL, 8th Ann. Rep. Geol. Nat. Hist. Surv. Minnesota, p. 66,
1880.

Orthis (Dalmanella) subaequata circularis (N. H. Winchell) Wi1ncHELL and ScHUCHERT,
Geol. Minnesota, vol. 3, p. 452, pl. 33, figs. 46, 47, 1895.

Pianodema subaequata circularis (N. H. Winchell) Basster, U. S. Nat. Mus. Bull. 92, vol. 2,
p. 978, 1915.

Pionodema cf. subaequata (not Conrad) Cooper, Journ. Paleont., vol. 4, No. 4, pl. 36, fig. 5,
1930.

Shell large for the genus, subcircular in outline; hinge narrow, slightly less
than two-thirds the width. Cardinal extremities obtuse; sides and anterior mar-
gin broadly rounded. Anterior commissure gently uniplicate. Very finely cos-
tellate, costellae crowded along the front margin and numbering 3 to 4 per
millimeter in the fold and sulcus region but 4 to 5 per millimeter on the flanks.
Hollow costellae not strongly swollen, concentrated on fold and in sulcus but
also scattered over most of the surface.

Pedicle valve unevenly convex in lateral profile and with the maximum curva-
ture near the middle; anterior third somewhat flattened ; anterior profile broadly
and moderately convex, most so in the middle and with moderately steep, flat
sides. Beak small and strongly incurved ; umbo swollen; median region swollen;
anterior third depressed to form a broad and shallow sulcus; flanks somewhat
flattened. Interarea curved, apsacline.

Pedicle interior with prominent oval muscle field; diductor scars elongate,
somewhat flabellate anteriorly ; adductor scars located on the sides of a promi-
nent median ridge.

Brachial valve moderately convex in lateral profile and with a strongly con-
vex umbo; anterior profile moderately and fairly evenly convex and with slightly
less depth than the pedicle valve. Umbo gently and narrowly sulcate, the sulcus
disappearing about one-third the length from the beak; median region swollen ;
lateral slopes moderately steep. Beak small, incurved. Median fold generally
indistinct. Brachial interior with small cardinal process having a short shaft;
brachiophore plates short and flaring. Median ridge low and inconspicuous.

988 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (117323)........- 20.8 19.6 23.1 13.0 12.0
€ (1a7gzna). piatick 18.7 17.4 10.5 12.5 II.0
‘ (E27924b rents stor 16.8 15.4 18.0 11.7 0.1
ce (48683 nesses 0.9 9.1 10.7 7.5 6.3

Types.—Figured hypotypes: 48683, 117323, measured hypotypes: 117324a,b.

Horizon and locality—Decorah formation (lon member—Phylloporina and
Fucoid beds) in Minnesota: At St. Paul; Kenyon, Goodhue County; Fort
Snelling, Hennepin County ; Milton, Dodge County ; cut 1 mile east, 1 mile north,
and 4 mile east of Wanamingo, Goodhue County; Wagner Hill, 5 miles south
of Cannon Falls, Goodhue County ; cut on the county road 1.1 miles east of U. S.
Highway 52 on the south edge of Cannon Falls, Goodhue County; Elmira,
Olmstead County.

Decorah formation (Ion member) on the Platteville road in Wisconsin:
3.5 miles southeast of Lancaster, Lancaster (30’) Quadrangle ; Wisconsin High-
way 10, + mile west of Ellsworth, Pierre County.

Decorah formation (Ion member-Phylloporina bed) in Iowa: At Decorah,
Winneshiek County.

Discussion —This species is characterized by its nearly circular form (L/W
usually 0.90 or greater), narrow hinge, strongly rounded contours, and generally
fine costellae. In size this species is like P. minnesotensis and P. subaequata
but differs markedly from both of them. The wide hinge and shouldered out-
line of P. minnesotensis are features which separate that species readily from
P, circularis.

Some specimens of P. subaequata have an outline like that of P. circularis and
have almost the same length/width index, but the former species is much more
strongly costellated than P. circularis. Furthermore, P. subaequata generally
has a strong concentration of swollen costellae in the median region.

PIONODEMA CONRADI (N. H. Winchell)
Plate 154, C, figures 12-14; plate 162, A, figures 1-6

Orthis conradi N. H. Wrncue tt, 8th Ann. Rep. Geol. Nat. Hist. Surv. Minnesota, p. 68,
1880.

Orthis subaequata Hatt (not Conrad), Pal. New York, vol. 1, p. 118, pl. 32, figs. 2e, f (not
2a-d), 1843.

Orthis (Dalmanella) subaequata conradi (N. H. Winchell) WiNcHELL and SCHUCHERT,
Geol. Minnesota, vol. 3, p. 449, pl. 33, figs. 37-39, 1895.

Pianodema subaequata conradi (N. H. Winchell) Basster, U. S. Nat. Mus. Bull. 92, p. 978,
IQI5.

Shell small for the genus, subcircular in outline ; hinge narrow, equal to about
two-thirds the width; sides and anterior margin rounded; anterior commissure
varying from rectimarginate to slightly uniplicate. Costellae of unequal size,
crowded, numbering 2 to 5 to the millimeter at the front margin; numerous cos-
tellae swollen and usually separated from each other by a very fine intercalated
costella at the front margin.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 989

Pedicle valve unevenly convex in lateral profile, the convexity located just an-
terior to the umbo and the anterior third to half flattened. Anterior profile
broadly and moderately convex. Beak small, gently incurved; umbonal region
swollen; median region inflated ; lateral slopes steep but anterior slope long and
gentle. Interarea moderately curved, strongly apsacline. Dental plates long ;
muscle field large and oval.

Brachial valve less deep than the pedicle valve, moderately convex in lateral
profile; anterior profile broadly and moderately convex. Umbo marked by short
and shallow sulcus; median region swollen ; lateral slopes short and moderately
steep. Brachiophore plates long.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (1173254)... 10.8 0.7 11.3 7.6 6.0
¢ Crs740a) ss... "OE 8.1 9.3 6.6 a

Types.—Figured hypotypes: 157494, 1173258.

Horizon and locality.—Platteville formation (McGregor member) in Wiscon-
sin: At Beloit, Rock County; 0.1 mile south of the Little Platte River on Wis-
consin Highway 81, 2 miles northwest of Platteville, Mineral Point (30’) Quad-
rangle; Janesville, Rock County; quarry on Wisconsin Highway 81, 1 mile
northwest of Ellenboro, Lancaster (30’) Quadrangle.

Same horizon in Minnesota: At Fort Snelling, Hennepin County; on U. S.
Highway 52, 2 to 3 miles north of Fountain, Goodhue County; Minneapolis.

Same horizon in Illinois: At Dixon, Dixon (15’) Quadrangle.

Discussion-—This is a small subcircular species with moderately strong cos-
tellae. At the median anterior margin of the brachial valve the costellae are often
alternately large and small and much crowded. This feature makes it possible
to identify poorly preserved or fragmentary specimens if this portion of the shell
is preserved. Its small size makes this species comparable to P. minuscula and
P. sulcata.

Pionodema conradi differs from P. minuscula in being more circular in outline,
having a narrower hinge, and in being more strongly costellate. It differs from
P. sulcata in being generally smaller and in lacking the prominent but narrow
sulcus on the pedicle valve of the Appalachian species. Moreover the costellation
of the two species is quite unlike because P. sulcata has fairly even costellae with-
out the anterior alternation.

PIONODEMA CRASSIPUNCTATA Cooper, new species
Plate 82, F, figures 23-27

Shell small for the genus, wider than long, transversely subrectangular in out-
line with the hinge slightly less than the midwidth which is the greatest width ;
sides nearly parallel ; cardinal extremities approximately a right angle; anterior
margin broadly rounded; anterior commissure gently sulcate. Surface multi-
costellate, 4 costellae in 1 mm. at the front margin. Shell substance coarsely
punctate.

ggo SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Pedicle valve unevenly convex in lateral profile and with the maximum con-
vexity posterior to the middle; anterior profile broadly subcarinate, with long,
steep sides and narrowly rounded median region; umbo narrowly convex, the
convexity continued to the anterior margin as a narrowly rounded fold; flanks
slightly concave. Interarea moderately long, apsacline.

Brachial valve with gently convex lateral profile having the maximum curva-
ture in the posterior part; anterior profile gently and broadly convex; sulcus
shallow, originating at the umbo and expanding anteriorly to the front margin
where it occupies about half the shell width. Flanks bounding sulcus gently
swollen; posterolateral extremities flattened and deflected slightly toward the
pedicle valve. Brachiophore plates widely divergent.

Measurements in mm.—Holotype, length 6.7, brachial length 6.2, midwidth 9.1,
hinge width 8.9, thickness 3.4.

Type.—Holotype: 117326.

Horizon and locality—Benbolt formation (base) in Virginia: 0.2 mile south
of the middle fork of Moccasin Creek, 14 miles south of Hansonville, Hanson-
ville (T.V.A. 205-SW) Quadrangle.

Discussion —This species is characterized by its transverse form, rectangular
outline, fine costellae, and the coarse punctae mostly radially arranged. This
species is more transverse than any of the other known species.

PIONODEMA MINNESOTENSIS Cooper
Plate 154, D, figures 15-190

Orthis (Dalmanella) subaequata WINCHELL and SCHUCHERT (not Conrad), Geol. Minnesota,

vol. 3, pl. 33, figs. 33, 34, 1895.

Pionodema minnesotensis Cooper, Journ. Paleont., vol. 4, No. 4, p. 379, pl. 36, fig. 14, 1930.—
SCHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, pl. 23, figs. 6, 10,
14, 1932.

This name was proposed for specimens having a wide hinge and distinctly
formed shoulders. It is ornamented like P. subaequata. It is also a robust species
attaining nearly as large a size as the largest known specimens of that species.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
ELOlOty Deh ons ocmis sire eres T72 15.3 20.0 16.0 10.0
Hypotype (117327a)... 17.0 16.1 19.2 15.2 mes
" (117327b)... 19.3 17.0 21.5 16.4 12.6

Types——Holotype: Y.P.M. S-1356; figured hypotype: 1173272; measured
hypotype: 117327b.

Horizon and locality—Decorah formation (Ion member ?) in Minnesota: At
Chatfield, Fillmore County; Minneapolis; St. Paul; and Fountain, Fillmore
County.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER ggI

PIONODEMA MINUSCULA Willard

Plate 155, A, figures 1-10; plate 155,G, figures 32-42
Pionodema minuscula Witvarp, Bull. Mus. Comp. Zool., Harvard Coll., vol. 68, No. 6, p. 275,
pl. 2, fig. 3, 1928.

Small for the genus, slightly wider than long ; hinge narrow; cardinal extremi-
ties obtuse; sides and anterior margin gently rounded; anterior commissure
broadly uniplicate in adults. Costellae fine, crowded, unequal in size, those on
the fold and sulcus stronger than those on the flanks. Costellae in fold and sul-
cus 2 or 3 in I mm.; on the flanks costellae number 4, rarely 5, to the millimeter
at the front margin.

Pedicle valve with uneven lateral profile, the posterior part convex but the an-
terior quarter somewhat flattened ; anterior profile gently and broadly convex;
beak slightly curved, somewhat erect ; umbo somewhat narrowly swollen; median
region convex; lateral slopes short and fairly steep. Anterior quarter depressed
gently to form a shallow sulcus. Interarea gently curved, apsacline.

Brachial valve about equal to the pedicle valve in depth, fairly evenly and
moderately convex in lateral profile. Anterior profile broadly and moderately
convex. Umbo with a small sulcus; umbo and median region longitudinally
swollen to form a poorly defined fold. Lateral slopes moderately long and gentle.
Interior with small cardinal process and widely spaced, subparallel brachiophore
supporting plates.

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
Holotype! wiack oes eis. <'s 12.3 11.8 137 8.8 7.0
Hypotype (1173209a).. 11.6 10.8 127 8.7 6.9
s (117329b).. 9.3 8.6 10.5 8.0 5.9

Types.—Holotype: M.C.Z. 8610; figured hypotypes: Columbia Univ. 26405
(1013)a-c; U.S.N.M. 117328, 117329a; measured hypotype: 117329b.

Horizon and locality.—Lebanon formation in Tennessee: At Lebanon, Wil-
son County; La Vergne, Rutherford County ; Columbia, Maury County ; Shelby-
ville, Bedford County; U. S. Highway 241, 14 miles southwest of Christiana,
Rutherford County; U. S. Highway 41 at Mount Olivet, 10 miles southeast of
Murfreesboro, Rutherford County; Wells Creek, Stewart County.

Camp Nelson formation in Kentucky: At High Bridge and 3 miles south of
High Bridge, Harrodsburg (30’) Quadrangle.

Witten formation in Virginia and Tennessee: At many localities but speci-
mens usually poor.

Hatter formation (Hostler member) in Pennsylvania: At Waterside, Everett
(15’) Quadrangle.

Discussion—This species is distinguished by its generally small size, sub-
quadrate outline, and fine costellae. It is thus like P. conradi but differs in its
squarer form, in its fine costellae, and generally wider hinge. It differs from
P. sulcata in its subquadrate rather than subcircular outline, finer costellae, and
lack of the conspicuous sulcus on the brachial valve.

992 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

PIONODEMA SINUATA Okulitch
Pionodema sinuata OKuLItTcH, Canadian Field-Nat., vol. 49, No. 6, p. 97, pl. 1, fig. 8, 1935.

Type.—Peter Redpath Mus., McGill Univ., Montreal.
Horizon and locality—Leray limestone=Chaumont in Quebec, Canada: At
St. Vincent de Paul and Pointe Claire.

PIONODEMA SUBAEQUATA (Conrad)

Plate 154, E, figures 20-24; plate 155, C, figures 14-18; plate 156, A, figures 1-13;
plate 157, D, figures 7-14

Orthis subaequata Conran, Proc. Acad. Nat. Sci. Philadelphia, vol. 1, p. 333, 1843—HALL,
Pal. New York, vol. 1, p. 118, pl. 32, figs. 2a-d (not e-f), 1847; Geol. Wisconsin, vol. 1,
p. 42, figs. 1-3, 1862—Em™ons, Amer. Geology, vol. 1, pt. 2, p. 194, pl. 9, fig. 2, 1855.—
Lestey, Geol. Surv. Pennsylvania, Rep. P4, p. 533, 1880.

Dalmanella subaequata (Conrad) Hatt and CLARKE, Pal. New York, vol. 8, pt. 1, pp. 1094,
207, 224, pl. 5C, figs. 6-11, 1892.—? WELLER, Geol. Surv. New Jersey, Paleont., vol. 3,
p. 156, pl. 10, figs. 3, 4, 1903.

Dalmanella perveta Hatt and CLARKE (not Conrad), Pal. New York, vol. 8, pt. 1, p. 224,
pl. 5C, figs. 13, 14, 1892.

Orthis minneapolis N. H. WINcHELL, 8th Ann. Rep. Geol. Nat. Hist. Surv. Minnesota, p. 63,
1880.—WINCHELL and ScHUCHERT, Geol. Minnesota, vol. 3, p. 448, pl. 33, figs. 30-32, 1895.

Pionodema subaequata (Conrad) ScCHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist.,
vol. 4, pt. I, p. 141, pl. 23, figs. 1, 5, 1932.—Coorer, Journ. Paleont., vol. 4, No. 4, p. 378,
pl. 36, figs. 1, 3, 1930.

Shell variable in outline and profile, large for the genus, subrectangular to
subcircular in outline; valves subequal in depth; hinge usually narrower than
the greatest width which is at the middle; cardinal extremities varying from
strongly obtuse to nearly a right angle; sides varying from moderately curved
to nearly straight ; anterior margin broadly convex; anterior commissure vary-
ing from nearly rectimarginate to broadly but gently uniplicate. Surface costel-
late, costellae generally crowded, unequal in size, the coarser ones concentrated
in the median region of both valves; strongly swollen and hollow costellae nu-
merous, scattered over the surface and concentrated in the median regions of
both valves.

Pedicle valve unevenly convex in lateral profile but with the maximum con-
vexity between the beak and the middle; anterior quarter to half of the profile
flattened ; anterior profile broadly convex with the median region elevated and
with long lateral slopes. Beak moderately long, slightly incurved; umbo some-
what narrowly swollen; median region full; flanks flattened to gently convex,
moderately steep; anterior slope convex, fairly steep. Anterior portion some-
what flattened to produce a poorly defined sulcus.

Brachial valve with fairly evenly convex lateral profile having the deepest
part at or near the middle; anterior profile broadly convex; umbo sulcate ; sulcus
shallow, disappearing near the middle; median region swollen, the swelling in-
cluding the anterior portion which forms an ill-defined fold. Lateral slopes mod-
erately steep.

Pedicle valve with small teeth, receding dental plates, and subflabellate muscle

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 993

field; diductor scars subcrescentic; adductor scars large, located posterior to a
longitudinal ridge that extends to about the middle of the valve. Apical plate
small but well developed.

Brachial interior with long brachiophores having divergent supporting plates
extended as ridges converging on the median ridge, cardinal process small, shaft
erect and short; median ridge low, extending anterior to the middle.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
RICE! Uy tiae soe tie ay ot ote talk 14.5 13.2 16.0 12.0 ? 8.0
Hypotype (48681a)............. 18.0 16.7 19.6 14.3 10.0
bs (COLE Ly Vee wae eS 16.5 15.1 18.1 14.8 0.3
Topotype and hypotype (123234). 14.5 ? 15.8 Tie7 2 4.0 ?
Hypotype « (85750)... 0... sre ores 20.3 18.2 22.4 17.4 12.0
ve PGE ATA) ss cei V soo saiate es 19.6 Tey) 21.7, 173 10.8
CONFI) hos wee celees 18.6 17.5 21.6 15.7 ? 13.1
ss (hia ie fe) (eee 16.1 14.8 17.9 13.5 8.8
‘ GEWZAB5 AD) arse es dhs cers 13.6 12.6 15.8 127, 7.8
¥ CTIFRESD) sek « o a’antioe 12.0 11.5 14.6 12.0 6.9
o DEGRA) 2 icine aisle e sees 15.8 14.4 ia 14.0 9.4
4 OUT AS shaw eisin's cucie’e 21.5 20.2 25.0 18.5 13.6

Types—Holotype (Cooper, 1930): A.M.N.H. 910; figured hypotypes:
48681a, 117232, 117335a,b, 117336a-d, Y.P.M. S1359; measured hypotypes:
1o127a, 85750, 86574a, 117330, 117332, 117333, 117334a, 117335a,b, 123234.

Horizon and locality—Decorah formation (Guttenberg member) in Wiscon-
sin: At Mineral Point, Mineral Point (30’) Quadrangle; Platteville, Mineral
Point (30’) Quadrangle ; Dickeyville, Grant County; Etna; to miles southwest
of Lancaster, Lancaster (30’) Quadrangle; Highland, Iowa County.

Same formation in Minnesota: At Minneapolis; West St. Paul; Fillmore,
Fillmore County; Spring Grove, Houston County; Fountain, Goodhue County.

Barnhart formation in Missouri: At St. Louis; Koch Valley School on U. S.
Highway 61, NE. corner SWiSW3 sec. 6, T. 41 N., R.6E., 2 miles south of
Barnhart, Kimmswick (15’) Quadrangle; 3 mile north of Riverside; 1 mile
southeast of New London, Ralls County.

Decorah formation (Spechts Ferry member) in Minnesota: At Chatfield,
Fillmore County; Gunderson Pit, 2 miles northwest of Zumbrota, Goodhue
County ; St. Paul; Minneapolis ; and Guttenberg member?, St. Paul.

Same formation in Wisconsin: In NW+3 sec. 19, T. 3 N., R. 1 W., Platte-
ville Township, Grant County.

Decorah formation in Iowa: At Clermont, Fayette County.

Auburn chert in Missouri: At Apex Station on the C. B. and Q. RR. south of
Elsberry; 4 mile east of Auburn, Elsberry (15’) Quadrangle.

Discussion—As here defined this species may be composite because it in-
cludes forms which are distinctly rectangular, whereas the type specimen is sub-
circular in outline. Inasmuch as it is possible to find specimens gradational be-
tween the subrectangular form and the subcircular ones, the name is believed to
cover the entire range. The rectangular types are located chiefly in Missouri,

994 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

but these are associated with rounder specimens. In some localities the subrec-
tangular specimens predominate. It is possible that refinement of the stratigraphy
in the Plattin group and Decorah formation of Missouri will show the predomi-
nantly subrectangular forms to have a different level from that of the rounder
ones.

The type specimen of P. subaequata is evidently a young specimen, but it is a
nearly circular form with numerous swollen costellae concentrated in the median
region of both valves. The stratigraphic level of this specimen is evidently the
Guttenberg member of the Decorah formation. According to Hall (1847, p. 118)
“The species occurs at Mineral Point (Wisconsin), in the Blue limestone asso-
ciated with Leptaena sericea, Orithis testudinaria, Delthyris lynx and other Tren-
ton limestone fossils.” A specimen from the Hall collection (123234) now in
the National Museum is a limestone plate containing a pedicle valve of P. subae-
quata having dimensions identical to those of the type specimen. In addition two
valves of Sowerbyella are present.

Pionodema subaequata is a large species for the genus and may therefore be
compared with P. minnesotensis and P. circularis. It differs from the former
in not having the shouldered outline, although the hinge of P. subaequata is
very wide. Pionodema subaequata has a greater proportion of swollen costellae
than P. minnesotensis. Pionodema circularis is readily distinguished from
P. subaequata by its strongly rounded contours and finer costellae.

PIONODEMA SULCATA Cooper, new species
Plate 155, D, figures 19, 20; plate 155, E, figures 21-30

Shell of about medium size for the genus, slightly wider than long with well-
rounded sides and front margin. Anterior commissure nearly rectimarginate.
Costellae fine, subequal except on the posterolateral extremities, numbering about
3 to the millimeter at the front margin.

Pedicle valve about as deep or slightly deeper than the brachial valve; lateral
profile uneven, most convex just anterior to the umbo and flattened in the an-
terior half; anterior profile somewhat narrowly swollen in the median region
and with long and moderately steep slopes. Beak elevated, slightly incurved ;
umbo narrowly swollen, the swelling continued anteriorly as a poorly defined
narrow fold to about the middle of the valve; lateral slopes long and moderately
steep and gently convex. Interarea curved, apsacline.

Brachial valve moderately convex in lateral profile, most convex in the me-
dian region. Anterior profile broadly convex and with the median portion slightly
flattened and depressed medially by a narrow sulcus. Umbo sulcate, the sulcus
shallow and narrow but extending anteriorly at least to the middle of the valve
or beyond. Median region inflated; anterior slope moderately steep; lateral
slopes short and steep. Cardinal process large, shaft long; brachiophore plates
flaring.

Measurements in mm.—Holotype, length 10.7, brachial length 10.0, width
11.6, hinge width 8.1, thickness 6.5.

PART I CHAZYAN AND RELATED BRACHIOPODS—-COOPER 995

Types.—Holotype: 117337a; figured paratypes: 117337b, 117338c,d,
117339a,b; unfigured paratypes: 117337c-j, 117338a,b,e.

Horizon and locality—Cave Creek formation in Virginia: Along the L. and
N. RR., 100 yards south of the water tank at Hagan, Rose Hill (T.V.A.
161-NE) Quadrangle; on U. S. Highway 58, 34 miles east of Cumberland Gap,
Wheeler (T.V.A. 153-SE) Quadrangle.

Nealmont formation (upper shaly bed, Conradella fauna) in Lewistown (15’)
Quadrangle, Pennsylvania: At southern (old) quarry of the National Lime
Company, Naginey; Reedsville.

Discussion —This species is suggestive of P. minuscula but may be distin-
guished by its strongly rounded form and the deep but narrow sulcus of the
brachial valve. It also suggests P. sp. 1 from Black River rocks in New York.
This unnamed species is like P. sulcata in having a prominent sulcus on the
brachial valve. The two may ultimately prove to be the same.

PIONODEMA TENNESSEENSIS Cooper, new species
Plate 162, B, figures 7-12

Shell of about medium size for the genus, wider than long, subrectangular in
outline ; lateral margins gently rounded ; anterior margin broadly rounded; hinge
wide but narrower than the greatest shell width which is at about the middle.
Anterior commissure nearly rectimarginate to gently uniplicate. Costellae mod-
erately strong, fairly even, about 3 to the millimeter at the anterior margin.

Pedicle valve having about the same depth as the brachial one, strongly con-
vex in lateral profile, and strongly convex in anterior profile. Beak large, ele-
vated, incurved; umbo swollen and with steep lateral slopes; median region
swollen ; anterior slope convex and fairly steep. Median region slightly flattened
in the anterior third; lateral slopes short and steep. Interarea long, curved,
apsacline.

Brachial valve fairly strongly convex in lateral profile with the maximum
depth at about the middle; anterior profile broadly and fairly strongly convex ;
umbo fairly deeply but narrowly sulcate, the sulcus extending to the middle or
slightly anterior to that point; umbo and median region tumid; lateral slopes
steep.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Boletype isu. chile ROe baa. 12.2 11.3 13.4 10.7 7.7
Paratype: (117340) 2 andes 13.9 12.9 15.4 10.7 10.1
a CIIZSUOE) oc rouse sk 11.7 11.0 13.7 9.8 6.0
« Cnegsugd)) 6. HO), 22 oe 8.9 8.6 II.I 9.5 5.9

Types.—Holotype: 117340a; figured paratype: 117340c; unfigured paratypes:
117340b,d.

Horizon and locality—Hermitage formation in Tennessee: On the east side
of U. S. Highway 70S-41 near its junction with Spence Lane 4.2 to 4.3 miles
southeast of Nashville, Hermitage (15’) Quadrangle.

996 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Discussion.—This species differs from P. circularis in its more convex valves,
proportionately wider hinge, and somewhat stronger costellae. It differs from
P. subaequata in having finer and more even ornamentation and narrower hinge.

PIONODEMA UNIPLICATA Cooper
Plate 154, F, figures 25-33

Orthis (Dalmanella) subaequata var. gibbosa WINCHELL and SCHUCHERT (not O. gibbosa
Billings), Geol. Minnesota, vol. 3, pt. 1, pl. 33, figs. 43-45, 1895.

Pionodema uniplicata Coorer, Journ. Paleont., vol. 4, No. 4, p. 379, pl. 35, figs. 1, 2, 1930.—
SCHUCHERT and Cooper, Mem. Peabody Mus. Nat. Hist., vol. 4, pt. 1, pl. 23, fig. 12, 1932.

This species was created for Pionodemas having a strong fold and sulcus.

Types.—Holotype: Y.P.M. S1358; figured hypotypes: U.S.N.M. 86571,
117341, 117342.

Horizon and locality—Decorah formation (Spechts Ferry—Ion?) in Minne-
sota: At Chatfield and Lanesboro, Fillmore County ; Fountain, Goodhue County ;
St. Paul; Minneapolis; Elmira, Olmstead County.

Decorah formation (Spechts Ferry member) in Wisconsin: At Platteville,
Mineral Point (30’) Quadrangle.

Same formation in Iowa: 4 miles east of Waukon, Allamakee County.

Platteville formation ? in Wisconsin: At Janesville, Rock County.

Discussion—This species is characterized by its strong fold and sulcus, fea-
tures that are not usual in the genus. Pionodema uniplicata is a homeomorph
of Doleroides gibbosus, and the two occur together in the Spechts Ferry mem-
ber of the Decorah formation. Specimens of Pionodema with strong fold com-
ing from post-Spechts Ferry horizons may be aberrant forms of other species,
but the limited representation of the species in the National Collection will not
permit definite determination of this point.

PIONODEMA sp. 1
Plate 154, G, figures 34-40

Shell small, wider than long, subquadrate to subcircular in outline; hinge nar-
row ; sides and anterior margin rounded. Costellae strong, numbering about 3
to the millimeter at the front margin.

Pedicle valve deeper than the brachial valve, strongly convex in lateral profile ;
anterior profile strongly arched and with steep lateral slopes ; umbonal and median
regions strongly swollen ; anterior slope steep. Interior with long, strong, flaring
dental plates surrounding the sides of a wide muscle field. Apical plate well
developed.

Brachial valve moderately convex in lateral and anterior profiles; umbo sul-
cate, sulcus short and shallow; median region swollen; lateral slopes short and
moderately steep. Interior with stout brachiophore plates flaring moderately,
their anterior ends extended at an angle toward the median ridge. Shaft of
cardinal process short; myophore small. Median ridge narrow, elevated, promi-
nent, extending anterior to the middle.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 997

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
BOS BSCE aus beth tests toieidatohs 7.5 6.9 7.7 6.0 4.9
CHOROR Ware ticki clas eiedeisi aie ses yey 6.5 7.7 6.3 4.9

Figured specimens.—86583a-c ; measured specimen: 86583d.

Horizon and locality —Chaumont formation in New York: Loose in the bed
of Black River just below the third dam at head of island, Watertown, Water-
town (15’) Quadrangle.

Discussion.—As noted above, this species is very similar, if not identical, to
P, sulcata.

DIORTHELASMA Cooper, new genus

(Greek di, two; ortho, straight; elasma, plate)

Shell minute, subrectangular in outline; sides rounded; anterior commissure
strongly sulcate; unequally biconvex, the pedicle valve much deeper than the
brachial valve. Surface somewhat distantly costellate. Punctate?

Pedicle valve with small teeth, curved and apsacline interarea, and: small, in-
curved beak. Delthyrium partially closed by lateral plates.

Dental plates receding, short, divergent. Delthyrial cavity shallow; muscle
field wide and short, with large diductor scars and short, narrow adductors;
floor of muscle field thickened. Vascula media strongly divergent when visible.

Brachial valve with shallow and narrow notothyrial cavity bounded by slightly
divergent or slightly convergent, erect brachiophore supporting plates; brachio-
phores long and slender; fulcral plates rudimentary; cardinal process varying
from a slender ridge to a thick triangular boss filling the notothyrial cavity.
Adductor scars small, elongate, the posterior pair located outside the anterior
pair ; no median ridge.

Genotype.—Diorthelasma parvum Cooper, new species.

Discussion—This genus can be briefly characterized as having an interior like
that of Pionodema or Fascifera, in combination with very unequal valves, the
pedicle one being deep and the brachial valve nearly flat.

Structurally this genus is allied to Pionodema and is the earliest known mem-
ber of the Schizophoriidae. The pedicle valve is deep and has a strongly swollen
profile. The dental plates are short and somewhat bowed and surround a wide
and short muscle field. No apical plate was seen in any of the specimens studied.

Inside the brachial valve the cardinalia are very close to those of Pionodema
but are often variable between specimens. In some instances the plates are fairly
closely crowded, in others they are fairly distant. The cardinal process is like-
wise variable. In some specimens it is a thin ridge, but in others it forms a
thick, triangular boss almost completely filling the notothyrial cavity. Up to the
present writing this genus has been found only in the Pratt Ferry formation,
Alabama, where it is fairly common.

998 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

DIORTHELASMA PARVUM Cooper, new species
Plate 146, B, figures 5-23

Small, transversely elliptical in outline with rounded sides but a nearly straight
anterior margin. Hinge wide, but not equal to the greatest shell width which is
at the middle. Valves strongly unequal, the pedicle valve having the greater
depth. Anterior commissure sulcate; surface costellate, costellae separated by
spaces wider than the width of the costellae, about 6 costellae in I mm. at the
front margin.

Pedicle valve moderately convex in the anterior half but strongly convex in
the umbonal region. Interarea apsacline; beak low, incurved. Anterior profile
broadly convex, most convex in the median region and with long lateral slopes.
Umbonal and median regions swollen.

Brachial valve very gently convex in lateral profile, broadly and gently con-
vex in anterior profile but deeply concave in the middle. Beak not prominent ;
sulcus originating at beak, wide and deep. Flanks gently swollen.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
EPOIGEY DE’ vec et eee es e's 2.1 1.9 eH! 2.2 1.2
Paratype (117322c)..... 22 BT 3.4 2.9 1.4

Types—Holotype: 117322a; figured paratypes: 117322b-h.

Horizon and locality—Pratt Ferry formation in Alabama: 0.2 mile southeast
of Pratt Ferry, Blocton (15’) Quadrangle.

Discussion.—The small size, transverse outline and pionodemoid interior iden-
tify this species, but no other species of the genus is yet known to which this
one can be compared.

Genus FASCIFERA Ulrich and Cooper, 1942

Fascifera ULrtcu and Cooper, Journ. Paleont., vol. 16, No. 5, p. 620, 1942.

Shell usually small, subcircular in outline, nearly planoconvex to unequally
biconvex, the pedicle valve always having the greater depth. Hinge narrower
than the greatest shell width; cardinal extremities obtuse. Anterior commissure
sulcate to rectimarginate. Exterior costellate to fascicostellate.

Interior like Pionodema with flaring dental plates in the pedicle valve and a
small plate at the apex of the delthyrium. Median ridge of pedicle valve only
slightly developed. Brachial valve with brachiophores long and thin with dis-
crete supporting plates converging slightly and uniting with the floor of the valve
on each side of the median ridge. Cardinal process long and thin with a nar-
row lobate crenulated myophore. Shell substance endopunctate.

Genotype.—Fascifera subcarinata Ulrich and Cooper, Journ. Paleont., vol. 16,
No. 5, p. 620, pl. go, figs. 1-5, 1942.

Discussion.—The general dalmanelloid outline and profile combined with the
internal features of Pionodema distinguish the species of this genus from other
punctate shells. Most species show a fair degree of fasciculation of the costellae,

PART’ I CHAZYAN AND RELATED BRACHIOPODS—COOPER 999

a feature that generally differentiates it from Pionodema. Like the latter, Fasci-
fera also has the swollen, hollow costellae that are a constant feature of the
Schizophoriidae. These hollow ribs are developed in varying degree among the
species, some having many, others few. They also complicate the identification
of species because their development in the same species is not uniform.

FASCIFERA CONVEXA Cooper, new species
Plate 268, B, figures 3-6

Small, subcircular in outline, valves subequally convex, sides and anterior
margin rounded; hinge narrow. Anterior commissure rectimarginate. Sur-
face finely costellate, costellae crowded and slender, 4 or 5 to the millimeter at
the front margin. Scattered swollen costellae also present.

Pedicle valve gently convex in lateral profile with the front third to half de-
pressed or geniculated toward the brachial valve; anterior profile somewhat
narrowly swollen in the median region with slightly convex, long, and fairly steep
lateral slopes. Umbo subcarinate, the carination dying out near the middle of
the valve.

Brachial valve moderately convex in lateral profile, broadly and moderately
convex in anterior profile. Umbonal and median regions swollen. Sulcus origi-
nating at the beak, narrow and moderately deep, extending from beak for about
two-thirds the valve length, becoming lost in the anterior swelling along the
margin. Flanks moderately swollen, short and steep sided next to the sulcus
but with long slopes to the margins.

Brachial interior with characteristic brachiophore plates.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
TAQIOUV PS | Bae ocvec sv outs 8.9 8.6 0.7 6.1 4.8
Paratype (117303b)..... 0.4 8.8 0.9 7.0 4.5?
ie CT I94036)) 43 «cic 9.3 8.9 9.4? 6.7 5.0

Types Holotype: 117303a; figured paratype: 117303c; unfigured paratype:
117303b.

Horizon and locality—PBenbolt formation in Tennessee: 1.6 miles northeast
of Heiskell; on U. S. Highway 25W, 200 feet south of Claxton, both on Powell
Station (T.V.A. 137-SE) Quadrangle.

Discussion—This species is characterized by its nearly circular form, the
fine, even costellae, the fairly strongly convex valves, and the small size. It differs
from F. subcarinata and F. dalmanelloidea in the ornamentation and circular
outline. It differs from F. stonensis in the small size and fine costellae.

FASCIFERA DALMANELLOIDEA Cooper, new species
Plate 149, A, figures 1-3; plate 153, D, figures 33-47; plate 153,'E, figures 48-53

Fairly large for the genus, valves subequal in depth, subcircular in outline,
slightly wider than long; greatest width at the middle; hinge about three-fourths

1000 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

the width; sides moderately rounded; anterior margin broadly rounded; an-
terior commissure uniplicate to faintly sulcate. Surface fascicostellate ; costellae
uneven in size, 3 or 4 in I mm. at the anterior margin; swollen costellae form-
ing nucleus of poorly defined fascicles.

Pedicle valve gently convex in lateral profile and with the maximum curvature
just anterior to the umbo; anterior profile narrowly convex in the median region
with long, moderately steep, flat lateral slopes. Beak slightly elongated ; inter-
area curved, apsacline. Umbo subcarinate, the carination continued anteriorly
nearly to the front margin as a low, narrow fold.

Brachial valve somewhat more convex in lateral profile than the pedicle valve ;
anterior profile gently and broadly convex and with a shallow median depres-
sion. Region just anterior to umbo and median region moderately swollen. Sul-
cus originating at the beak, narrow, moderately deep, continued as a narrow
groove anteriorly to the front margin. Flanks gently swollen, slopes to the median
sulcus long and gentle, lateral slopes gentle.

Pedicle interior with short apical plate cemented to sides of dental plates and
below delthyrial edge ; teeth small ; dental plates strong ; muscle field with elongate
diductor scars and short adductor scars; median ridge faint.

Brachial interior with long, strong brachiophore supporting plates; brachio-
phores moderately long; cardinal process slender but nearly filling the narrow
notothyrial cavity; median ridge low but extending into notothyrial cavity as
a thickening.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Ficlotygent tis ss< o's oes 8.9 8.7 10.6 7.8 4.4
Paratype (117305b).... 88 8.4 10.4 7.2 4.1
‘% (117304b).... 9.6 8.9 10.1 6.4 4.6
™ (117306a).... 10.7 10.1 T2a7 8.5 4.9
. (rr7364e). 2 7.2 6.8 7.6 53 3.0

Types.—Holotype: 117305a; figured paratypes: 117304a,d,e, 117305b,
117306a, 117307a,b,d, 117308; unfigured paratypes: 117304b,c, 117306b,
117307C,e.

Horizon and locality—Bromide formation (Mountain Lake member) in Okla-
homa: In the upper Io feet of the green shale (Platycystites bed) in the spill-
way of the dam on Spring Creek, sec. 17, T. 2 S., R. 1 W., Murray County ;
10 to 12 feet below the top of the purple and green shale in the cut on Oklahoma
Highway 18, 1.8 miles south of Sulphur, Murray County; upper green shale
(cystid bed) on west shore of Mountain Lake in E4 sec. 22, T. 2 S., R. 1 W.,
Carter County; 3 miles north-northeast of Springer; bed 13, 4 mile west of
U. S. Highway 77, NW4 sec. 25, T.2 S., R. 1 E., Carter County; bed 10, same
as preceding.

Discussion.—This species is very similar to F. subcarinata but differs in a
number of minor features. The Oklahoma shell has a deeper and more persistent
sulcus, a narrower and longer carination on the pedicle valve, somewhat stronger

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER IOO!I

costellation, and a shorter interarea and more erect beak. This species is rare
in Oklahoma.

FASCIFERA STONENSIS (Safford)
Plate 152, B, figures 14-30

Orthis stonensis SAFFoRD, Geol. Tennessee, p. 286, 1860.

Dalmanella stonensis (Safford) Hatt and Crarke, Pal. New York, vol. 8, pt. 1, p. 224,
pl. 5C, figs. 4, 5, 1892—Butrs, Alabama Geol. Surv., Special Rep. 14, p. 126, pl. 31,
fig. 16, 1926.

Shell large for the genus, slightly wider than long, with well-rounded lateral
and anterior margins. Valves subequal in depth. Hinge narrower than the
greatest width which is located at or near the middle. Surface marked by fine,
narrow, elevated costellae of unequal size, the larger ones forming the center of
more or less distinct fascicles which are best developed on the brachial valve.
Costellae of first and second generations swollen. Spaces between costellae
coarsely punctate.

Pedicle valve very gently convex in lateral profile, broadly convex in anterior
profile, and with median region slightly carinate. Beak prominent, umbo sub-
carinate with carination continued anterior to the middle of the valve. Anterior
portion only slightly folded. Umbonal slopes steep in the posterior part of valve,
flat in profile. Interarea moderately long, gently concave, moderately apsacline.

Brachial valve slightly more convex in lateral profile than the pedicle valve
and with the greatest convexity posterior to the middle. Anterior profile broadly
and moderately convex. Sulcus originating at the beak, narrow, moderately
deep in the posterior half, becoming wider and shallower anteriorly. Sulcus in
posterior third occupied by 2 costellae. Additional costellae implanted near the
middle on the outside and inside of the original 2; 2 primary costellae forming
the nucleus of 2 fascicles bounding the sulcus. Areas adjacent to sulcus moder-
ately swollen. Slopes to cardinal extremities moderately steep, slightly convex
in profile.

Interior of pedicle valve with diamond-shaped area. Brachial interior with
stout brachiophore supporting plates bounding a thickened notothyrial floor.

Measurements in mm.—

Brachial Hinge
Length length Width width Thickness
Hypotype (pedicle valve 118082a)..... 12.8 ? 13.4 7.8 3.1
ce (brachial valve 117309g).... ? 11.8 13.9 ? 1.8
i: Gipyaioa) MNT... sete «de. 15.6 14.7 16.7 10.6 8.0

Types——Figured hypotypes: 117309b,¢,g, 117310a, 117311a,b, 117312a,
118082a-c.

Horizon and locality—Wardell and Dryden formations in Tennessee: 14
miles northeast of Loyston, Maynardville (30’) Quadrangle; 30 feet above the
marble on the road along Little Sycamore Creek, $ mile northeast of the west
edge of the Howard Quarter (T.V.A. 162-NW) Quadrangle; about 2 miles
northeast of Tazewell; Flint Creek, southwest of Walker Branch on west side
of sharp loop, Powder Springs (T.V.A. 154-SW) Quadrangle.

1002 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Benbolt formation in Tennessee: In Raccoon Valley just east of Edgemoor,
3.1 miles southwest of Claxton, Clinton (T.V.A. 137-SW) Quadrangle.

Pierce formation in Tennessee: At old Pierce Mill on Stone River just south
of Walterhill, 74 miles north-northeast of Murfreesboro, Rutherford County.

Ridley formation on Kensington (T.V.A. 106-SE) Quadrangle in Georgia:
1 mile south-southeast of Cove Church, 5 miles south of Chickamauga; on U. S.
Highway 27, 4.3 miles north of Rock Spring.

Chickamauga limestone (=Ridley part) in Alabama: 2 miles southwest of
Argo, Birmingham (30’) Quadrangle.

Wardell formation (upper part) in Virginia: At Hagan, Rose Hill (T.V.A.
161-NE) Quadrangle= Woodway formation of Miller and Brosge.

Discussion.—This species is characterized by its large size, strong and sub-
equal convexity of the valves, the subequal depth of the valves, the strong cos-
tellae with numerous swollen ribs of the first and second generations, and well-
defined fasciculation. The individuals of this species attain the largest size of
any known species of this genus. The stronger ribbing, the numerous, swollen
ribs, more convex valves, and lesser carination of the pedicle valve distinguish
this species from F. subcarinata.

FASCIFERA SUBCARINATA Ulrich and Cooper
Plate 152, A, figures 1-13; plate 153, A, figures 1-6; plate 153, C, figures 10-32;
plate 155, F, figure 31
Fascifera subcarinata ULricH and Cooper, Journ. Paleont., vol. 16, No. 5, p. 620, pl. go,
figs. I-5, 1942.

Shell of about medium size, nearly circular in outline, with rounded lateral
and anterior margins. Hinge narrower than the greatest shell width which is at
about the middle. Cardinal extremities obtusely rounded. Surface costellate,
costellae appearing in 4 generations and somewhat fasciculate near the margins ;
4 costellae occupy I mm. at the front margin.

Pedicle valve gently and evenly convex in lateral profile, with elevated and
slightly incurved beak. Anterior profile subcarinate with moderately steep, flat-
tish slopes. Umbonal and median regions subcarinate, the angularity decreasing
anteriorly from the middle. Interarea slightly curved, moderately long, apsacline.
Delthyrium open except for a short plate at the apex. Interior with well-
developed, divergent dental plates defining shallow umbonal cavities. Diductor
scars elongate, adductor field moderately wide. Vascula media short, usually
indistinct, divergent.

Brachial valve more convex than the pedicle valve in lateral profile; anterior
profile broadly but gently convex; umbo gently convex; sulcus originating just
anterior to the umbo, narrowly U-shaped in outline, widening very slightly an-
teriorly and extending nearly to the anterior margin. Interarea short, anacline.
Brachiophores moderately long, acute, supported by thin plates that converge to
the floor of the valve on each side of the median ridge. Notothyrial cavity deep,
cardinal process small.

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 1003

Measurements in mm.—
Brachial Hinge

Length length Width width Thickness
Hypotype (117319a)... 8.6 8.0 9.6 7.2 4.3
$ (117315b)... 9.0 8.5 10.2 6.9 4.7
ss (117317a)... 10.0 9.1 10.8 7.7 4.6
‘is (107316D))-2.. 7B 10.7 12.7 9.5 4.8
x (E7280) sO 12.9 15.4 9.3 6.2
c CET7ZICL).c. O:4 9.1 10.9 8.2 4.5

Types—Holotype: 108198e; paratypes; 108198a-d,f-r; figured hypotypes:
117313a, 117314, 117315a,b, 117316a, 117317a,d, I117319a, 123233a, 123290a-C ;
unfigured hypotype: 123233b ; measured hypotypes: 117318a,b,f.

Horizon and locality.—Wardell formation and Wardell part of Dryden forma-
tion in Tennessee: In the vicinity of Lone Mountain, near Tazewell, Tazewell
(T.V.A. 154-NE) Quadrangle; just below and also 4o feet below the Hes-
perorthis zone in the Evans Ferry section on U. S. Highway 25E, 4 mile north
of Indian Creek, Howard Quarter (T.V.A. 162-NW) Quadrangle; at the bend
of the railroad just west of Liberty Hill, Dutch Valley (T.V.A. 154-SE) Quad-
rangle; on the west side of the sharp loop on the road down Flint Creek, in the
NW4 of the center subquad., Powder Springs (T.V.A. 154-SW) Quadrangle;
Nicely and Palmer’s store, $ mile east of Kate, Maynardville (30’) Quadrangle ;
4 mile north of Emory road, 2 miles northeast of Hall Crossroad, Fountain City
(T.V.A. 146-SW) Quadrangle.

Lower Ridley formation in Tennessee: 1 mile west of the courthouse in Mur-
freesboro, Murfreesboro (15’) Quadrangle.

Ooltewah formation in Georgia: On Georgia Highway 2, 14 miles northeast
of Naomi, Walker County.

Ooltewah formation in Tennessee: On the west side of Missionary Ridge,
Chattanooga (30’) Quadrangle; 2 miles southeast of Snow Hill Post Office,
Snow Hill (T.V.A. 112-NE) Quadrangle.

Wardell formation and Wardell part of Dryden formation in Virginia: Hes-
perorthis bed at Lloyd Carter’s barn 3 mile northeast of the school at Rye Cove,
Clinchport Quadrangle ; elsewhere near Rye Cove, Clinchport (T.V.A. 188-NW)
Quadrangle.

Discussion.—This species may be recognized by the strong carination of the
umbo of the pedicle valve, by the thin lateral profile, and the moderately strong
costellae. It differs from F. stonensis in the lesser depth and convexity of both
valves, the lesser strength of the costellae, and more strongly carinate pedicle
umbo.

FASCIFERA SULCATA Cooper, new species
Plate 153, B, figures 7-9

Shell of about medium size, slightly wider than long but subcircular in outline ;
anterior commissure deeply sulcate ; fascicostellate with about 2 or 3 costellae to
the millimeter at the front margin.

Pedicle valve with gently convex lateral profile; umbo strongly carinate, the

1004. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

carina extending to the front margin as a narrow fold. Lateral slopes flat but
long and gentle. Brachial valve gently convex in lateral profile; very gently
convex in anterior profile. Sulcus originating at the umbo and widening rapidly
to the anterior margin where it occupies fully half the width at the front
margin. Flanks gently convex, with steepest slopes into the sulcus and long,
gentle slopes to the margins.

Measurements in mm.—Holotype, length 9.7, brachial length 9.0, width 11.1,
hinge width 7.6, thickness 3.6.

Types.—Holotype: 117320a; unfigured paratypes: 117320b-e.

Horizon and locality—Upper Carters formation in Tennessee: Near Frank-
lin, Franklin (15’) Quadrangle.

Discussion.—This species differs from F. dalmanelloidea and F. subcarinata
which are strongly carinate at the pedicle umbo in having a still stronger carina
and one that is continued in strength to the anterior margin. It also has a
stronger and deeper sulcus in the brachial valve than either of species mentioned
above. Fascifera dalmanelloidea also has a shorter interarea, a more incurved
beak, and a much narrower profile than the other species. The Carters species
is more strongly costellate and fasciculate than the others. It should be noted
that the generic assignment is based on subparallel plates visible at the umbo of
the brachial valve when the shell is moistened. |

FASCIFERA sp. 1
Plate 143, G, figures 30-36

Shell small for the genus, wider than long, somewhat rectangular in outline;
sides and anterior margin rounded ; anterior commissure broadly sulcate. Sur-
face costellate, costellae uneven in size, about 4 to the millimeter at the anterior
margin.

Pedicle valve deeper than the brachial valve, moderately convex in lateral pro-
file and with the greatest convexity just anterior to the umbo; anterior profile
somewhat narrowly convex in the median region and with long lateral slopes.
Umbonal region convex, the narrowed convexity not extending noticeably an-
terior to the middle. Interarea moderately long, curved, apsacline. Beak
incurved.

Brachial valve gently convex in lateral profile, broadly and gently convex in
anterior profile. Umbonal region gently convex; sulcus originating at the beak,
moderately wide and deep. Flanks slightly inflated.

Measurements in mm.—117321b, length 6.3, brachial length ?, width 7.3, hinge
width 5.5, thickness 3.5?

Figured specimens.—117321a-e.

Horizon and locality—Ward Cove formation in Virginia: + mile west of
Pounding Mill, north of U. S. Highway 19, Pounding Mill (15’) Quadrangle.

Discussion.—This species is represented by a few fragmentary specimens only.
A small species is indicated which is not so strongly carinate in the umbonal
region as F. subcarinata, F. dalmelloidea, and F. sulcata. It is more strongly

ee a ae

PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 1005

costellate than F. convexa. The species is probably new, but better material
should be had before it is named.

Genus HIRNANTIA Lamont, 1935
Plate 145, D, figures 24-28

Hirnantia Lamont, Trans. Geol. Soc. Glasgow, vol. 19, pt. 2, p. 313, 1935.—A. WILLIAMS,
Quart. Journ. Geol. Soc. London, vol. 107, p. 97, 1951.

This genus was proposed in 1935 by Lamont, but it has never been described
or its essential characters given in detail. The allusion to its relationship to
Fardenia is incorrect. Several specimens of the genotype in the National Col-
lection from the Bala of Hirnant Valley, Wales, collected by Thomas Ruddy
show all the important anatomical details except the character of the shell
substance.

The specimens mentioned indicate a large, subrectangular shell having fine,
fairly even costellae. Inside the pedicle valve the dental plates are flaring and
short, surrounding a broadly oval muscle field. The diductor scars are subtri-
angular and moderately large; the adductor scars combine to form a wide and
triangular field between the diductors.

The brachial valve is characterized by flaring, strong brachiophore supporting
plates. The cardinal process is small with a moderately long, slender shaft sur-
mounted by a small lobate myophore. The median ridge is low and extends
nearly to the valve middle.

Genotype (by original designation).—Orthis sagittifera M’Coy, Ann. Nat.
Hist., 2nd ser., vol. 8, p. 398, 1851.

Discussion—Lamont thought that his genus was closely related to Fardenia,
differing from that genus in “having a simple cardinal process, markedly greater
convexity of dorsal valve, and radii of nearly equal calibre.” The entire structure
of Hirnantia is really quite different from Fardenia and indicates relationship to
Pionodema rather than any of the schuchertellids. The pedicle musculature is
like that of Pionodema but differs in having a wider adductor field and in lack-
ing the median elevation usually associated with the adductors. The brachial
interior is almost identical with that of Pionodema. The cardinal process is
fairly long shafted, and the shaft is surmounted by a small, lobate myophore.
The most distinctive feature of Hirnantia, and the feature most like Pionodema,
is the presence of brachiophore supporting plates. These are erect and flaring.
Fulcral plates are visible on one of the specimens (23960f).

Hirnantia differs from Pionodema in details of the ornamentation, the mus-
culature of the pedicle valve, and the stronger development of the structures of
the brachial valve. Nothing is known about the structure of the shell, whether
punctate or impunctate. Because of the similarity of the structures of the brachial
valve to those of Pionodema, Hirnantia is here placed in the same family as the
American shell.

Types.—Hypotypes : 23960a,b,f,g.

1006 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Genus and species undet.

Plate 99, C, figure 19; plate 148, A, figures 1-4; plate 217, D, figures 6, 7

Several specimens consisting of four pedicle valves and a possible brachial
valve having impunctate shell substance are considered to belong to an unde-
scribed genus. The shells attain a width of about an inch and have a straight
hinge wider or less wide than the midwidth. The pedicle valve has a moderately
long interarea with a very narrow delthyrium and narrowly convex pseudodel-
tidium. The interior of the pedicle valve is especially characterized by dental
plates so close together that they form an unusually narrow delthyrial cavity.
The exterior is marked by fine costellae and a moderately deep sulcus that origi-
nates just posterior to the middle and produces a short tongue.

The brachial valve tentatively assigned here and found in association with one
of the pedicle valves is ornamented like the pedicle valve but is also sulcate and
apparently has a short tongue. Bisulcate shells are not common. Consequently,
it is unwise to make a genus on these shells until the brachial and pedicle valve
can be definitely matched. The interior of this valve is marked by 2 long and
parallel brachiophore plates which bound a deep and narrow notothyrial cavity.
In this cavity is a short but stout cardinal process. The internal impression sug-
gests a long and flattish brachiophore.

Measurements in mm.—

Brachial Hinge
Length length Midwidth width Thickness
Pedicle valve (117068b)...... T.3 ? 14.2 15.8 ? ?
: * (1717066)... T2\2ds 19.3 ? 25.0 21.5 2 4.0
Brachial valve (117068a)..... ? 12.7 19.8 20.0 ? 2.0?

Figured specimens.—117066, 117067, 117068a,b.

Horizon and locality.—Arline formation (middle) in Tennessee: On the north
side of the old road in glade, 4 mile southeast of Friendsville, Concord (T.V.A.
138-SW) Quadrangle.

Base of Athens formation in Tennessee: Above the quarry 1 mile northeast
of the courthouse in Athens, Athens (T.V.A. 125-NE) Quadrangle; 24 miles
south-southeast of Riceville, Calhoun (T.V.A. 125-SW) Quadrangle.

Pratt Ferry formation in Alabama: 0.2 mile southeast of Pratt Ferry, Blocton
(15’) Quadrangle.

Discussion —The interior details of each of the valves described above are
unlike any other known genus, but until the valves can be definitely established
as belonging together it is unwise to create a genus for them.

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PART I CHAZYAN AND RELATED BRACHIOPODS—COOPER 1013

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PART t CHAZYAN AND RELATED BRACHIOPODS—-COOPER IOI5

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1016 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

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PART TI CHAZYAN AND RELATED BRACHIOPODS—COOPER 1017

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INDEX

(PRINCIPALLY TO GEOLOGIC FORMATIONS)

[For list of families and higher groups, see table of contents (pp. ix-xi) ; for annotated list
of genera and species, see pp. 138-186. Principal references are given in boldface type.]

A

Amsterdam formation, 29, 30, 32, 33

Anomalorthis zone, 127, 129, 130

Antelope Valley, Nevada, 126

Appalachians, 10, 36

Arbuckle Mountains, 11, 118

Arkansas (northern), 117

Arline formation, 32, 39, 41, 42, 43, 46, 50,
53, 60, 61, 64, 71, 72, 73, 74, 75, 82, 86, 96,
124, 128

Ashby stage, 8

Athens formation, 33, 39, 41, 43, 44, 49, 56,
64, 82, 93, 123, 124

Attalla (conglomerate) formation, 38, 45,
55, 76

Auburn chert, 113, 117

Austin Glen member of Normanskill forma-
tion, 34

Aylmer formation, 17, 18, 19

B

Bacon Bend member, 45

Barnhart formation, 112, 116, 117, 118

Barrel Spring formation, 129

Bassler, R. S., 2, 5

Bays formation, 38, 45, 907

Beckett formation, 114

Beekmantown formation, 7, 88

Beldens formation, 31, 32

Bell, W. A., 5

Bell, W. C., 4

Bellefonte dolomite, 51

Beloit dolomite formation, 113

Benbolt formation, 8, 30, 45, 53, 56, 58, 59,
63, 66, 68, 69, 71, 73, 76, 82, 83, 86, 87, 90,
96, 123, 128

Ben Hur formation, 48, 66, 81

Benner limestone, 48, 66, 91

Blackford formation (facies), 38, 40, 45, 48,
49, 55, 56, 57, 62, 64, 72, 76, 85, 100

Black Hills, South Dakota, 11, 125

Black River formation (or group), 1, 7, 8,
9, 22, 27, 52, 55, 70, 92, 107, 125

Black River Valley, New York, 22

Black Rock formation, 15

Blockhouse (shale) formation, 33, 49, 93

Bloomsdale formation, 114

Bolarian, 7

Botetourt formation, 42, 43, 49, 53, 59, 60,
61, 62, 64, 73, 74, 98, 124

Bowen formation, 50, 98

Bridge, J., 2

Bromide formation, 107, 118, 120, 128

Buffalo River series, 113

Burchards formation, 32

Burden conglomerate, 34

Bureau, R., 15

Burkes Garden member of Benholt forma-
tion, 46, 50

Butts, C., 2, 5

Cc

California, formations in, 129

Camarocladia zone (beds), 59

Camp Nelson formation, 105, 106

Cane Creek formation, 51, 56, 65, 103, 106

Carlim limestone, 51

Carman quartzite, 31, 32

Carters formation, 51, 55, 78, 92, 102, 103,
104, 105, 106, 107, III, 112, 116

Central Basin, Tennessee, 11, 99, 100

Centre Hall member of Nealmont formation,
52, 71, 79

Chambersburg formation, 15, 34, 52, 53,
79, 81

Champlain Valley, 10, 27, 31, 32

Chatham Hill formation, 46, 53, 97

Chaumont formation, 7, 16, 19, 20, 22, 24,
26, 27, 30, 32, 33, I10

Chazyan, I, 7, 18, 92, 108, 123

Chazy group, 8, 14, 15, 17, 23, 27, 28, 31, 36,
68, 7I, 103, 125

Chickamauga limestone, 18, 43, 45, 49, 53,
54, 55, 56, 83, 100

Chota formation, 56

Cliffield formation, 48, 56

Cliffield group, 56

Cloche Island formation, 26, 27

Cloud, PK... Jr..:5

Clover member of Loysburg formation, 56,
62, 65, 76

1019

1020

Coboconck, Ontario, 13, 23, 25

Coboconck formation, 25, 26

Cobourg formation, 18

Cole, 0. 'C., 3

Collierstown formation, 56, 70, 81, 112

Columbiana formation, 33, 44, 57, 74, 75, 85

Cooper, B. N., 1, 2, 3, 6, 7, 9, 37

Cow Head breccia, 13

Criner formation, 121

Crown Point formation, 14, 28, 31, 32, 72,
74, 87

Cryptophragmus, 7, 23, 26, 39, 58, 63, 65, 66,
89, 92, 98, 90, IOI, 102, 105, 107, 108, 114

Ctenodonia bed, 111, 112

Curdsville formation, 55, 77, 103, 104, 106,
Di2) 113

Curtin formation, 57

Cybeloides bed (zone), 53, 59

Cyrtonotella zone, 43, 46, 49, 59, 60, 61, 71, 84

D

Day Point formation, 14, 28, 32

Decker, C. E., 3

Decorah formation, 22, I10, 113, 123

Desmorthis zone, 127

Devonian facies, 40, 41

Dot formation, 57, 72, 85

Douglas Lake member of Lenoir formation,
57

Doylesburg member of Shippensburg forma-
tion, 57, 58, 63

Dryden formation, 46, 58, 81, 96, 97, 90

Dunbar, C. O., 3

Dunleith formation, 113

Dutchtown formation, 114

E

Echinosphaerites-Cyrtonotella zone, 71, 84

Edinburg formation, 8, 11, 15, 34, 35, 39, 43,
46, 49, 52, 53, 59, 71, 74, 84

Edmundson, R. S., 6

Effna formation, 42, 43, 49, 50, 53, 56, 59,
60, 61, 64, 71, 73, 74, 75, 82, 98, 124, 128

Eggleston formation, 61, 78

Eidson member of Lincolnshire formation,
61, 66, 73

Ellett formation, 62

Elway formation, 8, 48, 57, 62, 64, 74, 77,
93, 94, 97, 120

Eureka group, 127

Eureka group (Dark shale with Reuschella),
128

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 127

Eureka group (25-foot sandstone), 127

Eureka group (Yellow limestone), 128, 130

Eureka quartzite, 81, 128

Everton formation, 114, 117

Everton-Jasper formation, 117

Eyer (limestone) member of Hatter forma-
tion, 62, 63, 65, 66

F

Facies (in Appalachians), 38

Fannetsburg member of Shippensburg forma-
tion, 57, 63, 91

Farragut formation, 63, 67

Fascifera beds, 54

Fetzer tongue, 44, 49, 64, 98

Fillmore limestone, 130

Five Oaks formation, 56, 64, 73

Fleanor formation, 65, 66

Frog Mountain sandstone, 57

G

Galena formation, 107, 113

Gilbert, R. C., 3

Glenburnie member of Chaumont forma-
tion, 24

Glenn Falls limestone, 33

Glenwood member of Platteville formation,
106, 109

Grand Detour formation, 110

Gratton formation, 46, 58, 65, 96

Grazier member of Hatter formation, 62, 65,
66, 68

Great Basin area, 11, 125

Greencastle bed, 65

Gull River formation, 23, 25

Guttenberg member of Decorah formation,
27, 70, 107, 108, 110, TEX, Ir2,"EIG ary

H

Hager formation, 114, 115

Ham, W. E., 5

Hanson Creek formation, 128
Hardy Creek formation, 65, 81, 103
Hatter formation, 7, 51, 56, 62, 66
Hatterian, 7

Hebertella exfoliata zone, 28
Heiskell shale, 66

Hermitage formation, 66, 103
High Bridge, Kentucky, 11, 99, 105
High Bridge series, 105

Hintze, L. F., 3

PART I

Hogskin (shale) member of Lincolnshire
formation, 8, 39, 40, 61, 65, 66, 67, 72, 73,
82, 90, 94, 123

Holston limestone (or marble), 66, 67, 75,
79, 86, 93

Hook member of Macy formation, 115

Hostler member of Hatter formation, 7, 51,
63, 66, 68, 60, 72

House limestone, 130

Housum member of Mercersburg forma-
tion, 69, 70, 78

Hudson Valley, 10, 27, 32, 33

Hull formation, 18, 22, 24, 31, 33, 35, 112, 124

Humber Arm series, 13

Hunterian, 7

Hurricane Bridge formation, 46, 69, 76

I

Iberville shale, 31

Ibex area, Utah, 130

Ion member of Decorah formation, 30, I10,
112, 113, 124

Isle la Motte formation, 30, 31, 33

J

Jacksonburg formation, 69
Jasper formation, 117
Joachim formation, 114, 117
Johnson, H., 3

Joins formation, 118, 119, 127
Juab limestone, 130

K

Kanosh shale, 130

Kauffman member of Mercersburg forma-
tion, 65, 70, 71, 78

Kays GoM. 12) 3) 5,22

Kentland, Indiana, disturbed area, 11, 106

Kimmswick formation (Missouri), 81, 103,
113

“Kimmswick” limestone (Tennessee), 103

Kindle, C. H., 3

Kirk, E., 2, 5, 126

Kittatinny limestone, 69

Knox formation, 7, 54, 62, 78

2a
Ladd; HS. 5
Lantz Mill facies of Edinburg formation, 39,

58, 59, 71, 73
Larrabee formation, 31, 33

INDEX

1021

Lebanon formation, 54, 55, 78, 81, 92, 98,
IOI, 102, 104, 105, 106, I10, 115

Lehman formation, 130

Lemont member of Carlim formation, 7, 51,
71

Lenoir formation, 14, 29, 32, 39, 40, 41, 42,
44, 48, 57, 62, 64, 72, 74, 78, 87, 88, 93,
04, 97, 117, 120

Leray member of Chaumont formation, 16,
18, 20, 24

Leray-Rockland beds, 20

Lévis shales, 14, 126

Liberty Hall facies of Edinburg formation,
II, 39, 45, 53, 59, 71, 73s 87, 98, 124

Limestones (facies), 39

Lincolnshire formation, 8, 15, 49, 56, 57, 59,
60, 61, 62, 64, 73, 74, 79, 80, 84, 87, 93,
94, 95, 97, 98, 123, 128

Little Oak formation, 43, 45, 61, 74, 75, 85, 86

Loeblich, A. R., Jr., 3, 5

Long Point series, 12, 13

Long Savannah formation, 38, 40, 75, 76, 81

Lowell Park member of Platteville forma-
tion, 113

Lowville formation, 16, 18, 19, 22, 23, 26,
27, 29, 32, 34, 35, 39, 52, 54, 55, 66, 102, 107

Loysburg formation, 51, 56, 66, 76

M

Maclurites, 7, 31, 51, 54, 55, 68, 71, 92, 127

Maclurites zone of Lenoir formation, 72, 97

Macy formation, 114, 115

Magnolia member of Platteville formation,
108, 109, 110

Mahan formation, 76

Manitoulin Island, 13, 26

Marcem formation, 76

Marmor stage, 8, 19, 83, 92, 108

Martin Creek formation, 60, 77, 87, 93

Martinsburg formation, 70, 73, 77, 89

Mascot dolomite, 94

Mazourka formation, 129

McGregor member of Platteville formation,
108, 109

McLish formation, 14, 29, 118, 119

Meadow marble, 78, 79, 90, 94

Mercersburg formation, 52, 59, 63, 65, 60,
70, 78

Merriam, C. W., 3, 5, 126

Middlebury limestone, 31

Mifflin member of Platteville formation, 108,
109, 110

Mingan formation, 13, 14, 29

1022

Mingan Islands, 13, 14

Minneapolis limestone, 113

Mississippi Valley, 11, 22, 108, 113

Mississippi Valley (middle), 113

Mississippi Valley (upper), 108

Moccasin formation, 38, 50, 55, 78

Mohawk limestone, 32

Mohawk Valley, 10, 27, 32

Montreal, 13, 15, 16

Moore Hill formation, 26

Mosheim formation (facies), 30, 48, 54, 64,
78

Mountain Lake member of Bromide forma-
tion, 120

Mount Merino member
formation, 33

Multicostella convexa zone, 121

Murat formation, 68, 79, 98

Murfreesboro formation, 48, 49, 54, 55, 88,
92, 99, 100, 104, 108

Mystic conglomerate, 8, 15, 3f, 36, 127, 120

of Normanskill

N

Nachusa formation, 110

Napanee member of Rockland formation, 22,
24, 25

Nealmont formation, 52, 57, 70, 71, 79, 80, 87

Nemagraptus zone, 33, 36, 75, 85, 123, 124, 125

Neuman, R. B., 3

Newfoundland, 10, 11, 12

New Market formation, 79, 80, 89

Nidulites-Lambeophyllum beds, 89

Nidulites zone, 46, 59, 60, 71, 87, 95

Nolan, T. B., 5

Normanskill formation, 33, 34, 36

North Cambridge, New York, 36

O

Oak Hall member of Nealmont formation, 52,
79, 80

Oil Creek formation, 118, 119, 127, 129, 130

Ooltewah formation, 80

Oranda formation, 8, 34, 43, 52, 53, 56, 58,
59, 65, 70, 81, 82, 88, 80, 103, 105, 112,
125, 128

Oregon formation, 106

Orthidiella zone, 126

Ottawa group (or formation), 18

Ottawa limestone, 18

Ottawa Valley, 10, 13, 17, 18, 19, 22, 27, 33

Ottosee formation (= facies), 66, 82, 91

SMITHSONIAN MISCELLANEOUS COLLECTIONS

VOL. 127

P

Palliseria (Mitrospira) zone, 119, 126

Pamelia formation, 16, 18, 19, 22, 23, 25,
40, 108

Paperville formation, 33, 44, 45, 57, 82, 83

Pearisburg limestone, 66

Pecatonica member of Platteville formation,
108, 109

Peery limestone, 53, 56, 76, 83, 87, 93, 95, 114

Pelham limestone, 56, 83

Phillipsburg thrust slice, 31

Phylloporina bed, 112

Pierce formation, 55, 76, 91, 92, 100, 104

Pinesburg member of Shippensburg forma-
tion, 43, 46, 63, 83, oI

Pioche District, Nevada, 129

Platteville formation (group), 107, 108, IIo,
113, II5

Plattin formation, 117, 118

Plattin group, III, 113, 114, I17

Pogonip group, 12, 15, 31, 119, 126

Pooleville member of Bromide formation,
120, I21

Porterfield stage, 8, 36

Poteet formation, 84, 87, 93

Poughkeepsie, New York, 35

Prairie du Chien formation, 106

Pratt Ferry (limestone) formation, 9, 36,
43, 53, 57, 75, 82, 85, 86, 08

Prosser formation, 22, 82, 113, 124

Prouty, GC. Bt

Q

Quebec City formation, 15, 35

Quebec City region, 13, 14

Quimbys Mill member of Platteville forma-
tion, 110

R

Raymond, P. E., 3, 5

Red Knobs formation, 38, 41, 60, 86, 90, 93

Reeside, J. B., 5

Rhinidictya bed, 111

Rhysostrophia zone, 127

Rich Valley formation, 36, 42, 45, 53, 56, 57,
60, 73, 83, 86, 87, 98

Ridley formation, 47, 54, 55, 68, 69, 76, 81,
92, 97, 99, 100, LOI, 104, 105, 108, 123, 128

Rob Camp formation, 76, 85, 87, 93

Rockcliffe member of Aylmer formation, 17

Rockdell formation, 66, 87

PART I

Rockland formation, 7, 8, 9, 13, 17, 18, 19,
20, 22, 24, 26, 27, 30, 33, 36, 52, 59, 70,
102, IIO, 125

Rock Levee formation, 110, 113, 114

Rockwood formation, 54

Rodman member of Nealmont formation, 79,
82, 87, 88, 89

Rostricellula zone of Lenoir formation, 72, 94

Row Park formation, 76, 80, 88, 89

Rysedorf conglomerate, 15, 34

S

St. Clair facies of Murfreesboro forma-
tion, 88

St. Lawrence Valley, 10, 13

St. Luke member (facies) of Edinburg
formation, 71, 87, 89

St. Martin formation (member) of Aylmer
formation, 14, 16, 17, 72

St. Paul group, 89

St. Peter sandstone, 106, 108, 114, 117

Salona formation, 59, 70, 77, 81, 87, 88,
89, 113

Sandstones (facies), 38

Selby member of Rockland formation, 22,
24, 25

Sevier formation (= facies), 38, 30, 47, 67,
78, 90, 93, 94

Shadow Lake formation, 23, 25

Shales (facies), 38

Shannondale member of Benbolt
tion, 46, 90

Sherman Fall formation, 18, 22, 113

Shippensburg formation, 43, 46, 52, 57, 59,
63, 69, 71, 79, 9X

Shrock, R. R., 3

Sillery formation, 15

Simpson group, 118

Sinclair, G. W., 3

Sinuites zone, 78

Snyder member of Benner formation, 48,
68, 91

Sowerbyites zone, 120

Spechts Ferry member of Decorah forma-
tion, I1O, III, 116, 125

Speers Ferry formation, 91

Stictoporella bed, 110

Stinchar-Balclatchie formations, 8, 43, 75, 82

Stones River group, 52, 55, 91, 92, 100

Stose, G. W., 2

Stover member of Benner limestone, 48, 92

Strasburg formation, 92

Stringtown formation, 125

forma-

INDEX

1023

Surgener formation, 38, 40, 93
Swan Peak quartzite, 130
Swift Current formation, 26, 27

+

Table Head series, 6, 8, 11, 12, 15, 28, 31,
36, 126, 127, 129

Tank Hill formation, 129

Tellico (sandstone) formation, 15, 38, 41, 43,
83, 90, 93, 94

Tetradium cellulosum, 7, 26, 34, 35, 54, 58,
65, 69, 102

Thompson Valley formation, 94, 95

Toqua formation, 94

Toquima Range, Nevada, 126

Trenton stage, I, 9, 13, 22, 27, 35, 52, 54, 55,
83; 107, 123; 124, 125, 326

Tulip Creek formation, 118, 120

Tumbez formation, 72, 77, 94

Tyrone formation, 27, 105, 106

U

Ulrich, E. ©., 1,.3; 5,7
Utah, formations in, I1, 130

V

V alcourea-Mimella zone of Lenoir forma-
tion, 72

Valcour formation, 8, 14, 16, 18, 29, 32, 72,
74, 87, 88

Valentine member of Curtin formation, 57,
80, 94

Valley View member of Curtin formation,
57, 94

Vestal marble, 94

Viola formation, 123

WwW

Wahwah limestone, 130

Walker Mountain sandstone of Moccasin
formation, 95

Wappinger (limestone), 35

Wappinger Creek belt, 35

Ward Cove formation, 46, 53, 56, 50, 66, 67,
69, 73, 77; 83, 85, 87, 94, 95, 123

Wardell formation, 8, 46, 48, 50, 58, 63, 65,
68, 69, 71, 73, 81, 82, 91, 96, 97, 98, 99,
100, IOI, 105, 106, 108, I10, 114, 123, 128

Wassum formation, 53, 97

Watertown member of Chaumont forma-
tion, 24

Wells Creek basin, 11, 99, 104

1024 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127

Wells Creek dolomite, 104 Witten formation, 7, 9, 19, 23, 39, 45, 48, 50,
Wetmore, A., 5 58, 63, 69, 78, 81, 89, 90, 92, 98, 99, 102,
Weybridge member of Beldens formation, 31 105, 106, 108, 115
Whistle Creek formation, 62, 80, 97 Womble formation, 125
Whitcomb, L. D., 3 Woodway formation, 69, 99
Whiterock stage, 7, 15, 28
Whitesburg formation, 11, 39, 40, 56, 73, Y
97, 98

Yellow Branch member of Poteet forma-
tion, 85, 99
Youngman formation, 31, 32, 34, 35, 36

Whitewood formation, 125
Wichita Mountains, 11, 118
Wilderness stage, 8, 92
Willard, B., 5

Wilson, A., 5 Zz

Wilson, C. W., 5 Zell member of Macy formation, 115, 116

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