AN FEY TPIS TIEN Fae EST 9 NET ererieatecy pespuceecs a ee eee cred pate iy tae sean eens = Arby fe 1] TH HI HH | WHT ane HH AIA IAAI Hl WHI] Wi mM MI AH Hi | SL HI ne ie wie ; As wit SVIHUL YUN tO ANOLSANVYS Gay: ‘OadVHOTOD AGNNOYUOAAGH AIL NI SdOO GHL FO NAGUVD CNV MVYWd SAMId ira out tong Sree | a1W1d AZAXFS WIID010s9'S A TWELFTH ANNUAL REPORT OF THE UNITED STATES (JEOLOGICAL AND GEOGRAPHICAL SURVEY OF THE TERRITORIES: A REPORT OF PROGRESS OF THE EXPLORATION IN WYOMING AND IDAHO HO RWB Yr AR 187 Ss. IN TWO PARTS. | Part JI. By F. V. HAYDEN, UNITED STATES GEOLOGIST. CONDUCTED UNDER THE AUTHORITY OF THE SECRETARY OF THE INTERIOR. WASHINGTON: GOVERNMENT PRINTING OFFICE. 1883. TWELFTH ANNUAL REPORT OF THE UNITED STATES GEOLOGICAL AND GEOGRAPHICAL SURVEY. ACES Ae We GEOLOGY, PALEONTOLOGY, AND ZOOLOGY. (it) Is NAG nee TABLE OF CONTENTS. BU Tsk Cs poset cs ice etret aya ect yeh UMA OUE kPa oS Rd ee PO CUI 2 AM tale Le PENIS VOLi CON TETAS cers ck bers re ere teas cre et eat ae ha ra MRO IT aa ee MEL HOL: Ol CLAN SIU hail cries eee yep rk ee Sein cape erent) eae a 2 sea SECTION I.—GEOLOGY AND PALEONTOLOGY. EomE ORTON C. AN WEEE NIMH) sei eet wei oats aeons ey eal utc ators MGS hes Of ti rym Sra ee ea aes aa UR es Se eN ce ghpe lg Le dca aN OI gy Contributions to invertebrate paleontolegy: No. 2. Cretaceous fossils of the Western States and Territories......-... No. 3. Tertiary mollusca from Colorado, Utah, and Wyoming .....-.--.. Nossal Hossilsjof othe; Waramie Croup) aseen sence cee close tees eee eee No. 5= Triassic fossils of Southeastern Idaho.........-..-.-.-...-------. No. 6. Carboniferous fossils from the Western States and Territories .... No. 7. Jurassic fossils from the Western Territories..........---.------- No. 8. Carboniferous fossils from the interior States ...-..--..------ «0. REPORT OF ORESTES ST. JOHN: Mebterrorgirans mii hale ew ee APACE Sen ae Wee cua, UL tMeAKaar ie athacalmtin AUC CMn Oey y Report on the geology of the Wind River District ..-.........--..-...--.- CHAPTER ——Areazan dob OUM Caries oie ela ne ek npoe anole ats Se CHAPRER EE Wy Oming, Rant 6c ce ote aces tee aces aataielte ais alae wcrcis) CHAPTER IJT.—Hoback-Green River Basin -..----.--. --.--- ecce eeoeee ee CHAPTERVLV,.—_ Gros) Ventre Range so. aee eee none soso aco eee ae leisciaes OHAPTER Ve —— GLOSHVOM Ley bss iT ae) tae aye tae ual ay Ue ee es LAU CHAPTER Vil Winduiver Rangves soos. sssoe tee ome coe cinelc name ca wicreenets CHAP TH Ra VAde—— WET Cal iVieRyls ASTI se sine patra arate Sian eras pare aa cere REPORT OF SAMUEL H. SCUDDER: ; The Tertiary Lake Basin at Florissant, Colo...-.. 2.2... 2-0 ------ oon aoe GeO] Dyin ea ae yaa oy ea aye OA in tees MR LORE aig CRU UI VE Rua ACD aC anu a Pa COT LOLO myn ree eee alee eee re eis Cem ee Gish space MA aA ca GL Te eR ehep et POR VE LOLISSATI Diem co sessy ae ee ee rece es ere a erga era ean EVO SrctiIon II.—ZOOLOGY. REPORT OF A. S. PACKARD, JR: Monograph of Phyllopod crustacea: PAE OMT CLOMY eee te eee eter ee eee ye aN ich dl Uy ce ainwee uk wah re Lae Histormotuhesubordersbhyllopodaserccc.socce esas ee eee eee oce ae Tae weay by A Data ay apy a Wie eeeh pee ses hy Coeae yi ed Nt ea eo SE areola PON SE amily eA podtd canes ste eit oe cpm eee) aoe enna SL Ge UE aie Nord Geological succession of the Phyllopoda.....-....---2. .---.--+--+---0 Geological distribution of the Phyllopoda........---.-.-------------- Monplioloc van ama bom snes aie ses ee aU cmokl ae Dae na aa cntale @ Development, metamorphosis and genealogy...---..--------.-------- Reproductive habits of Branchiopodidw--.. .....-.-..----.----------05 Systematic Position of the Order Phyllocarida ..-.........----------- LEA Gin ABKOTCEEN IE, cytes Sas Sete ry Aloo ea lA I ST a MN EES ESI EO SAD yaar rst clavate Mat mei RA ik earache a wearate ics Gs a aly ere lenalaters BATT YS GT CLERC ees slat este ate yi REE A ts ty ie a, cee A ya GO a Ne REPORT OF R. W. SHUFELDT: PBeOlOmyn ot SPeOLyLO. CUM M arta ome eeee nels cecte ties aw ek elects Seem ees Mintemlooy.Ob Wremopiila: Alpestris)ss 2222-0 sh clon soeede cnawer pcleceocese en Osteology of North American Tetraonid@...... 200.0 cane5 cone ween enenee Osteology of Lanius luidovicianus excubitorides........-.--------------- Sep OP yAOLA CACAO tren san anisacwca cea Sele cacieet smedneledamee deere Ai rs . t ie Pik iN LIST OF ILLUSTRATIONS. PALEONTOLOGY. ACCOMPANYING C. A. WHITEH’S REPORT. Facing page. REATES | tt —13.—hossilimolluseaj ns a25 cc oc nccelaaci= se lesnel=essio4 = Bae nbees 40 EOFS POSSi LT OUTS Cae aa ae ee a he ah ay ee 48 90-30.—Fossil mollusea...-- Sh AN a SHE OH pee Ug LA ITA NEY ce SER Ny RI eta 104 PL yl BOYSHSH LUNG 08X 0) DSY CY Heyy aS A ca A eR en a 118 Sd-GOs=—— LE OSS LM O MTS Caer e ayes eso ete a ae rea etn ms a Aran SAL Ae ea 142 B1=—385—— FLOSSHW Tin OTIS Gene ape FUT cot a Ce AN RN sl 154 DO 42: = OSSL MM OVNASC Bieta se et aye stare era ae ete aN calc ee Tee IMU al 172 GEOLOGY. ACCOMPANYING ORESTES ST. JOHN’S REPORT. Facing page. Plate = Hobacks Canons ve slice Bie a Oe UAL IBV AL tye ee aL 181 i Upper Valleys Hobacle hutven ees ems tees eee eee 182 III.—Panoramic view of the Gros Ventre Range.-....-.--.-------. 187 IV.—Geologic sections, Hoback Camion. -...--..---.-...--..------ 189 Vie PATOL ATTIC (pve CWS io see eee aly Og Ee LILA) RNA 190 V1I.— Panoramic views, Snake River Valley ....-........-.---.---. 191 VII.—Geologic sections ‘through Sartrom NWS aoe i eka as Neuen bi 193 VIII. —Panoramic BTU EN its tee ot ee SY TL LEE RS Sy Bi NR Re URS eh 196 PX —— Geolosicyseeriones- 2... scissile einen ae ce eee es 201 DG] RAM OKOL ETH ATU AUS eS et peat ae a a eA TARE UE LO Ute OOM 203 XIE AO DIUNC VTS Wy ss eee NE SE NY Se ch Seon ae ALN Ty OM SR ee 204 XII.—View and section, Green River Valley..--...----..----.----. 207 XU ——Geolosie sections see seo sae nae tae ce els ieee eee cea eee ae 208 XIV.—Panoramic SVE VV earn eas recep ea Ra NL BL EON UAL sa 210 DX Vie = ad OL ATT Cheval Oya aes es a ares oN ae pel ea MNO Rs 212 XVI.—Panoramic view, from Gros Ventre Peak ..---....-..---..--- 215 XVII.—North flank of the Gros Ventre Range.......-.--.-------.--. XVIII.—Gap between Wind River and Gros Ventre Ram cese ens seen 220 UG ACTOS WWI VEN oto ac ese eas osecosseadey sasos secousoas 223 XX. Geolovicysectionseeecwe Masa ce cece ee eee ene een Seoee see ec aasS 227 XXI.—Cafion Gf north forks omGreenukiver eae ee se eee ee eee 228 XOX -— PATOL ATION Copyal Oyen sree yy tee TLL NERY A URL Se eR area 299 XOXO: ——-Greemiysvier © Amon yes yl ey Geen ane is Nt BRAN Hae 930 XXIV.—Morainal ridges, West Flank of Wind River Range. .-.---.-.--- 231 XX V.—Entrance to Green River Cation ........-.....--.-.----.----- 23 XXVI.—Geologic sections, Wind River Range....-....--..----.------ OB) XX VII.—West flank of Wina RiversvanoOnsssavsease escctecies seesaw 3 XXVIIT.—Geologic sections, Wind River Range SoSGoy oodoKN ca6ous aooaso 235 XXIX.—Geologic sections, Warm Spring Creole dunia ius Sarangi |S 236 XXX. —Permo. Canbontferous!SecbiOlnse Heer ee ee ee 238 XXXI.—Geologic sections, vicinity of Torrey’s Creek ......---..----.-- 239 XXXII.—J unction of North Pork and) Wand River 222.25... cee cesee 240 EXOXeXI —— Geolosie seCtlomats seme ec ie e eels daisies eles Sar ase Se ca 241 BNONO NOTIN 6 —— FAT) ON UTNT Cl ave ives ay ct het a tas esac esl See ach ANAT Sci UCC ea ae 241 PRONOXGV = FEC ATT OM eee nent ml NINO. ea He a lee i wade ee SRR ie 242 POOR 1. —Geolocice section, hed Canon 22. loess lees. cceceuncecceenee'e 243 XXXVII.—Dry Creek Cation, WIC W AMGSeChlOMaa-n)se eer seis sate ecenae 244 XXX VIII.—Bull Lake Fork, view and section........---- sees cceuee seccne 245 XXXIX,—Bull Lake Fork COP 1 TiO) § VUES aie FS TE Re ae Lh a ee ee Cs 246 Vill ‘ LIST OF ILLUSTRATIONS. Facing page Prate XUL.—Geologic section, north side of Bull Lake Fork.-..--..--------- 248 XLI.—Bull Lake and section ----.... ---- ---- -----+ ---- ++ +--+ -e--0:- 249 XLII.—Geologie sections, vicinity of Red Cation.....----------------- 250 XLII.—Canon, North Fork of Little Wind River..--- sh ae chen Se ee Bey) arr XLIV.—Geologic sections ..-. .----- ------ -----+ s2- 222 cece scene ee eee 252 XLV.—Panoramic view and geologic sections ...--.------------------ 253 XLVI.—Wind River Valley and Togwotee Pass..-..-----.------------- 255 XLVII.—Profile of Upper Wind River Valley ..------------------------ 258 XLVIII.—Wind River Valley-..--.----.-------------------------------- 260 XLIX.—FiG. 1%. Orifice of Ancient Spring. Fic. 1». Section of Ancient Spring. Fig.2. Arch, Warm Spring Cation. Fic.3. Section. 267 ACCOMPANYING S. H. SCUDDER’S REPORT. Map of Tertiary Lake Basin at Florissant, Colorado ...--.-.------------------ 293 ACCOMPANYING A. 8. PACKARD’S REPORT. Page Fig. 1.—Limnetis gouldii...-....---..----------- o-oo ee eee eee eee eee 299 3) — I] Li TMOINS WADCOKONERHUIS) cococs so5G50 coco suatos soooeo soso S45 coed HONS 300 3.—Front of head of Limnetis mucronatus, &c..-.....-..--..----------- 301 A. bimneune) (ORO WAUIEOME) 64 sosobe be sodE Gosaas Hoe ocoGued coo60d 4 ae fame Mies het 301 5.—Limnetis brevifrons, front of female ......--------..---- ------------ 302 6.—Limnetis brevifrons, outline of shell, &c...--...---..---.- wa aaeleuee 303 AS eulneain, CaeOeMG cos so5s60 cd5440 God650 cob ho daSsd5 Bagg 550080 accs 304. 8.—Hstheria compleximanus) ------ 522. 2... 2. c--- ome eon neem ene oe = 306 9.—Estheria compleximanus, hand .........--..----------- +--+ s---+---- 306 TOAD NCHA MOEACATE Coo cn6 Sees cabo cddo cob Gon HOGoou DoSccE SS55 CsESe0C06 308 iL —Joistlnerelay, \wellitiemen oaS5 cash oda sacasooSasud Gobo dhbncoscSsbSSco0 oSsece 309 112} DUNNE) TOMER 6 oSe G5 dob S65 Ghod codeoo Gd coun boSd Sacdos eediags coooss se 310 13 ——WimnadiaamMerleama ese hesae cee nein sreereeseislels ciao oaie a faratata eter aietee te 310 14, — aoe hey APIS Coos c46o6as Cogan soon5d coon coDo Goades Sdn don56s< 311 1b Hullo Kohes Croll Ph obi ate ods Fano Seb obS aoe a bodses oneSeo Sooo SsS 314 IGNOU) Clowar boven ANE ee ee BAA Ae BAe RS Goub adda oodo Good 325 Ie Am Lemay Ona Cl Sye meme eemiee nel ssisla Sere nia clamins seksoe eee ele eee are 330 1eF——Arbemiayeracilisys sje = lene =)e aa )eoeiele nisin aia Sond sone bose nod 331 19/— Branchinectacoloradensisner soca eee aneee eee ee ee ee ee ae eee eee 338 20'=Streptiocephalus}texanusiee ns seseen cece sce ee eee eee eee eee eee ee ao ik—-SuLeptocephalugmseali MNeadme = anise renee ease aeons ee eee - 348 2Qo'=Chirocephaluspholmantes sete 2 oe sce Say joeec cle sae ete ee eee eee 352 25: haMmnocephlalmssp) aby UIcUs eee hese yee ele ee ee a ae eee eee 354 DACA Avelyn feat ence esis eieichannis a Ste sche Sere ioe err ane Se Sere ere ee ae 358 2Os— NeCtIOMIOLAPUS A: Soee eae ek caece Scie Roel | We eI eS ae irae 361 26;——SectiomoreApug se eer eee cero ae ae Bees Base Sais aN Pee 390 27 eT Ey eyes OEMS) Ow MIOINE saceo eas beeGboUsUe CoOaCe poboes Sseobes oe) AOA 28.—One of third pair of limbs of Moina ............-- i aaah, maak Neeser at 405 29s Man dibblerofathre lol store ss is oe yas 2) a Sh ade TS in ey Ea - A06 30. birstrame seconds maxalliiasomlobstereseriee eae see eee eee ’ 406 ol:——hirstimaxallipede of the) lobsterssseesc 2 eee nee sees eee ee ee 406 32; second maxillipede othe Tob steree ns = se nyce cine oo eee ee 406 Sos hindamaxdilipeder ot thelobster =. 5 see sees eee e yee nae 407 SAL NECLION NUN TO UGA US eases) eee ey rele eyes ek pete erase ea on nea pe 409 Sos Maxill aOt lobsters sas specie reales ee ss Sats trols opt ae a iawn ef ea 409 TOSCO WOW TING NTE oS) soo5 aoo5 dogo sua bobdoe oS eSs cass aode ae Le 409 37.—Section through the abdomen of Limulus .......--.-. 2-502. 24. 22.2) 409 38.—NSection through the head of Limulus ---.......-.-2-2222222 2222. ee A410 39 —Diagrammatic section through hypothetical Limulus-like form ..---. 410 40.—Section through a trilobite (Calymerfe) .............--2.----1.-22.-- 410 41.—Longitudinal section through Limulus.................-..---------- 411 42 Nauplius or mimmadia berm anny sesjae alesse ae ere eee AST AB =I Denne) Oit IbitsabneXeben Invan yeu bay Coe e a be boeo ase oddaddoe boeoes soos es 416 A4°—— Nap lins orp Apus)cancritor mais 2 ceye aie) so scien aba eee 416 AS: Nauplinsoriepidunuss..2 220222 252 oic oes ce ee eee eee ~ 416 AGL Nohenaeetel IehAve) Obie) OMe ooo Gob 5 Goes abba eee GooKes Soba boe lo 417 A7;—Nauplins of branchipus)staonalis..022 224000 ee 417 48.—Male frontal tentacle of Chirocephalus holmanni, B. Eubranchipus--.. 424 49.—Female frontal tentacle of Chirocephalus holmanni, B. Eubranchipus.. 425 50.—Left clasper of larva of Streptocephalus texanus.....-...---...-.---. 427 LIST OF ILLUSTRATIONS. IX Page Fig. 51.—Right clasper of larva of Streptocephalus texanus --..--....-.---.-.- 428 52.—Right clasper of larva of Streptocephalus texanus -....---..--.-..... 428 53.—Right clasper of larva of Streptocephalus texanus.-..---.--....---.. 28 54.—Cast-off skin of Streptocephalus ....-...-.-.----.--.-------.-------. 428 55.—Bristles of second antennze of larval Eubranchipus GOSH SERA STIR eE 429 56.—Sete of first maxille of Eubranchipus .--------- .----.----....---.-- 429 57.—Aunterior antennex of pale Eubranchipus..---.---..-----------.---.-- 429 58.—End of abdomen of the larval Hubranchipus.-.---...........-.-.--..- 430 59.—Seta of first maxilla of the Streptocephalus.--.-..--.-------......-..- 430 60.—Right male clasper.of Eubranchipus _....----..----.-.-------------- 430 ol —Hemaleclasper of Hubranchipuss: nse ee ees saeeee sees seseee eee cese 4ST 62.—End of abdomen of larval Eubranchipus -------------........-...... 431 63.—End of abdomen of larval Eubranchipus .-----.--.-...---...---.---- 431 64.—Head of abdomen of larval Eubranchipus ...--..-:--..----------.--- 431 65:—Section ofbrain' of Nebalia) Wipes) 422- See se sen ee ee sae eee Sess o- 43 66.—Section through thurax of Nebalia bipes ...-.....-...---2-..--------- 439 67.—Section through end of thorax of Nebalia bipes..---..----..---..---- 440 68:—Hmbryo of Nebaliaiready to hateh 6225-2252) Cees se see seo ee - 442 69.—Hymenocaris, Peltocaris, Ceratiocaris, Dictyocaris, Dithyrocaris, Argus ES YroU GUNDAS (Ce) oct) We He Sa ey a aT a To aoe ee 444 TY AD (lav toreeM ate OT CMERTTS 445 69566 Seg eeediee sose = doeegs eas] badeae caqo ue 45, 71.—A. Echinocaris multinodosus; B. Ech. Buble see ie eine es Ne 451 62) Di SCINOCATISEDTOWMIATWA ee pas os ey — oes Sete e ON ele tee ator NI IED 451 G3. Dit hy TOCALIS NEVLUMU wee ies oye oe lela Meelevee sede nee alae le Galea ee lepetes 45% LIsT OF PLATES. Facing page PLATE T.—Limnetis mucronatus, with details.............--.....---..----- 561 ie himmnetis: couldn. with Gdetalls\s.eec ees see eee eee a eee ae 518 Li Nscheraibeliraceisan dn Onesiiiesp sense se ee eee eee eee 520 live Hsthenia calitornica, wath details) ss--ss secs eee ee cence eo. 522 Ve tisthenlaycompleximanustseaesee eerste eee eee ee eee eee 524 VI.—Eulimnadia texanus, with details .-.-....---.-.--...-----.----- 526 VIl.—Eulimnadia texana and agassizii, details sea ear Ea a 528 NWA Ar temmantertilisadetall sae seam te cee eee ie arene aoe ieee 530 IX.—Branchinecta paludosa, Swab etek Mev mete hee eye eae IE 532 X.—Branchinecta arctica and coloradensis, details ...--...----.----- 534 XI.—Branchinecta. lindahli and Branchipus vernalis -........---....- 536 XIT.—Streptocephalus texanus, details.-._-........._--.--.---.------: 538 MT —Chirocephalus holmant, details 222222.-5:----222.-2222--- s.-2- 540 XIV.—Thamnocephalus platyurus, details era SNe NS SSPE Reale wiatiesaial aleracee 542 xe —— AUS eam Ge le pu Gn Sy ere sce et ry yl ancl SN A Dn UO UL Re ae 544 XeVATE = At iis) air Gael CUTS ee way oie tages earns ay eta ry Oe 546 XV A puss awilclikde hails ese Selene ey GS PRN SM DIR eel ee RES a ye Cane 548 PREV ATI App ir ssanwy tlre weds eee en aN aa ae 5 PROTEXG—— Ap sow Hy Le evil gaia Sane ets a ey SEI ES RU WE el ran 552 BRON = AN US uve by Ve tears tes AUR ake teaee tc, NOL UNE aaa) Se aa, alaee 554 POX Arp si awvelits acl e tell es sey cae ee ee SNe OI OR) aN ANN oa Oe a 596 XXII.—Artemia and Branchipus, details .....- 222.222.2222.) 2.2... 558 ACE ATLA aLeMIS, etal Syme nee see w oy oe yits. Suoa L RU dean 560 ROXCUVE Ss Mera dehallsns enn eee e cnc o oat ome ee Me) ms nasi 562 XONOV FH Stherilay me xcieamay eval siya palsies aye cveveeyemiet toise ay alts) MN ELLE 564 XXVil—Estheria,morsel, ete., with details).2 2. ob 07 e e ea oe 566 XXVII.—Limnetis brevifrons, details.........--..- es Ne aS 568 eX Eispheria Mexicana ebe.,(Qebalise ays o ene vee une alee ue re ene 570 XOXEEX —Eistolos yoy Phvllopodaseeece eee saeco te ee ese ene eee see ae 572 XXX.—Histology of Branchipus and Streptocephalus .-..---.....------ 7 eXeXe — Amn atomiy Of ApUSiccme a eee meets noe ecion cu Kil eS eA VT aT 576 PXOXeXHIE AMA LOM VOL AD USe eee a Piece ace See mice ce si nyte Sarr Uare Ene Ly NES MMO —Histolosy of Bstheria, be ee. se se ol decane t isoee eeeelcoee 580 XXXIV.—Development of Streptocephalus, ete....-.---.----..---.---..-- 582 XXX Vi —Development of Apus lucdsamus-- 222 .-222-- 2-2-2 o2ee ssecee ones oe 584 MOO 1. — Anatomy, of Nehalia bipes a\.2.-2). 205 e/a ose -toeae see ee cde) |) SO XXX VII.—Anatomy of Nebalia bipes.. ISIN EN ay sa) USa ees RE a ede pM EES SERA Ey SS XXXVIII.—Embryology of Nebalia..-.-...- oe pea aae apeataeiea reves OO. XXXIX.—Transformation of Artemia and Branchipus .. See eee etre ey KOR And a Zoo-geographical colored map. x LIST OF ILLUSTRATIONS. ACCOMPANYING Dr. R. W. SHUFELDT’S REPORT. Page Fic. 1.—Speotyto cunicularia hypogea -.-----.-------- e2e--+ e- +2 +--+ - =e 593 2.—Speotyto cunicularia hypogea -.----..----- -2-- eeenee --2- ween ee -- == 594 3.—Head of Eremophila alpestris ....-- seal ay cee tee BAA Seon OBO Gaae 628 4,—Centrocercus urophasianus..-. .----- 22+ e----- eee e ee eo = eee - 656 5.—Canace obscura.----. --- 22. eons oe ene eon oon econ ne meee eee e ne eee ene 655 6.—Canace ODSCULa---- -2 26 enn e on = ewes woe ce ono = een ne on we nnn == 656 7.—Cupidonia cupido...-....---. .-2-22 -- 6+ -- enon ee ene eo eens eee ene 8.—Cupidonia cupido.... ..---- 2-06 eee eee eee nee moe wen enn ne cone cen nne 669 @)——Isomacey wumalll, 364 coed aoeoos Sob h60 codon Sacaes ceaboe saBDOS asbes0 Be) Sy 10.—Bonasa umbella -..---. ---. 22-22. ween ee ooo o ne ooo ee ee ene een wenn 660 11.—Centrocercus urophasianus.......-.------- ---- -2------ ---- ---- ---- = 672 12.—Pedizcetes phasianellus ......---.---.----6- ----- Dod GooESe maps Sodos 678 13.—Pedizxcetes phasianellus ....-.-.-.-----2 ------ + ~~ -- 2 = ooo - =e 684 14.—Lagopus albus .... .--.-. ------ e222 Foon ne oe nnn oe nee eee ee enn nee = 688 15.—Ortyx virginiana .----- ..---- 22 enn - enn woe se nee eee ene Sage cooc 693 1G —Orainyxs {GH o56 eooco0soco6 be6d 6 cq5beb bon6 Gado aeos 65000086 So50G5 GcOs 695 17.—Callipepla squamata......----.------ ---- ---- 2222 cece eee eee eee cee 697 18.—Lophortyx californica .....-. .----- S000 605 cos600 60 oo ooso ods odoe 698 1). OWaeiromnyax, WARING). oS 666 ooo agb6se So sase coocde coooce chen Secsed asec 700 20.—Pseudogryphus californianus (facing page)...--..----------------.- tod 21.—Pseudogryphus californianus...... J.---2.----. .---------- == ene 730 22.—Cathartes burrovianus.... ..-. 22. 2 oo 22 none coe ce wens ones wenn 2 > 393 OBL ORMIMENUES BUNS 549 SoG665 6500 pdodes Goosod DoGacs cooSen Soe ialelaraeinateiate 733 Oil ——(OenIagIIStR) GYRE) 6555 co dod0 cobG6 066 6o55 GeoRebboES dogses SeoSoecoT 733 25. — CRN ATHIES AMD oo6bc5 chon ob5ond cooHds sooado cobesb NSdOO GosEse Soc5c0 742 20: Cabbarisharalavaeeeaemecseiiseeeines eeiste sinter eeiactertectecieetseia= ae mmmnat cD 2/.—Pseudosryphus califormianus .----. =... 2.26 cose Soc none coc eee anne 749 28.—Pygostyles of Vultures and Hawks......- Be AE ee ENN Nets 1 761 29.—Ribs of Cathartide and Walconida.... ....---. 2-222 cone cone cone coe 763 30!—Coracoid of Pseudosryphus)sas.ieee emis oe els asie eee nisin aleeeieiee eer 766 Slr Cathanistaratra tas soce sees oclae ae cseiae seco caseieescte een eee eee 767 32. NeCOphronspercuoplrenusys json ese eeeeesclenie seal Sameer aiciee SEES eG 767 Soh Onbyonis lnm OMI) 855 Gop dco b ee asda ss coUHoG choo boooao ode desc open’ WEF 34: Cathartes aura soos se acse etc ce te asvseci cece mine ceicclne cia sia neni erate V7 3 OHI NPR ENE Soooos SooreE rene ub be Gso0 Cobo Seca beobeeoseduoseacapes |. ail 36: Cabharbes aura ooo 2 SUE ce See ee ee eee Swi oleae) arene W71 Sas Oathartes aura ose so. kee coe ese ea ee Se eee 772 30:-— Catharishal alata ise ciecse de cone cel sleeps stot wise see seonse toe sees 772 39:—Capharistaatrata sass. . csosoniece cence: Ce aS tS NS URL a ea a 777 40; Pseudocnyphus caltorlanusessceee eer eee eee ee eee eee eee eee 780 4 Pseudosryphus) calitornianusye. cesses acjecccceiees acess cae cece eee 782 Facing page. PLATE I.—Skeleton of Speotyto cunicularia hypogea-.........--.------ 622 II.—Osteology of Speotyto cunicularia hypogea .......----..- cee) G24 III.—Osteology of Speotyto cunicularia hypogea ..---..----.------ 626 IV.—Osteology of Eremophila alpestris ....-...------------------- 652 V.—Osteology of American Tetraonidsw..---..--......-..---.----- 702 ViI.—Osteology of American Tetraonide.........-..----- edicieeieee 704 VII.—Osteology of American Tetraonida@....--..2---------.---- o--6 706 VIII-—Osteology of American Metraonids: -22 2252-2222 asses 708 IX.—Osteology of American Tetraonid@....-....--...---..-------- 710 XK.—Osteology of American Tetraonid@...--.....-.. ---.---------0 712 xi — Skeleton! of American Netraonida----.----2 -foa22 s2eee. eeeeee 714 XII.—Skeleton of American Tetraonide .-.........---2..----------- 716 XIil.—Skeleton of American Tetraonidw.-.-....-....-...-2c2-. --<-- sg efits XIV.—Osteology of Lanius ludovicianus excubitorides .......-...-.- 726 XVi—Osteolosy ofthe Cathartideores ses ssececee sees cs ee eee eee 788 NVile—Osteolonyiot the) Cabharbideossee ssa ane He ees eee a 790 xv lIe— Osteolosy, of the Cathartidws. 22.2542 54eee eee eee 792 XVIIT.—Osteology of the Cathartide.................-..------ eee od xix —Osteology, of the Cathartida-<)o sea ss5-ee cee cee one eee ee 796 xexe— Osteology of phe) Cathartideaese ssc saee seen ee ee mae mean 798 XXkT.—Osteology of the Cathartides..-. 2.22 s.-. ---- --- 2 oo eee cece 800 XXII.—Osteology of the Cathartide......-. 2.2... 2-2-2. eee ee ene eee - 802 XX ——Osteolosy of Huei Cathartideass2n> soe ese e eer oe ean ae 804 XXIV. —Osteology. of the: Cathartide: 222.255.2225 2 ee ae 806 LIST OF ILLUSTRATIONS. MAPS IN ACCOMPANYING POCKET. 1.—Hecomonic map of portions of Wyoming, Idaho, and Utah. 2.—General geologic map of the areas surveyed in Wyoming, Idaho, and Utah. 3.—Geologic map of part of Central Wyoming. 4.—Geologic map of parts of Wyoming, Idaho, and Utah. 5.—Geologic map of parts of Western Wyoming and Southeastern Idaho. 6.—Sheet of panoramic views of Wind River and Teton Mountains. XI abt ioe . { Genial WalGu ie LETTER TO THE SECRETARY. OFFICE OF THE UNITED STATES GEOLOGICAL AND GEOGRAPHICAL SURVEY OF THE TERRITORIES, Washington, D. C., January 1, 1879. Sie: I have the honor to transmit for your consideration and for pub- lication the twelfth and last Annual Report of the United States Geolog- ical and Geographical Survey of the Territories. This report includes the labors of the corps for the field season of 1878, and the office work until the close of the existence of the Survey by law June 30, 1879. Sev- eral of the members have, however, performed very important work since that time in elaborating their individual reports, which has added greatly to their interest and value. A general summary of the work for the season of 1878 will be appro- priate in this connection. Owing to the length of the session, Congress did not pass the usual appropriation for the work of the Survey until July, and consequently the period for work in the field was compara- tively short. The headquarters of the Survey was at Cheyenne, Wyo., the same as the preceding season. Four parties were organized, but in suchamanner that in case of necessity they could be divided for special duty. All our outfit and animals were transported from Cheyenne to Point of Rocks and Green River Stations, on the Union Pacific Railroad, and from thence the parties pursued their way northward to their respective fields of labor. To the first division, in charge of A. D. Wilson, was confided the pri- mary triangulations of the entire area to be surveyed. Hight of the most important peaks were employed as stations, with some minor points. Among the more important stations were Wind River, Fré- mont’s, Grand Teton, and Sawtelle’s Peaks (near Henry’s Lake); also several of the most conspicuous points in the Yellowstone Park. This division was robbed, near Sawtelle’s Peak, of all its animals and a por- tion of its outfit, so that at least half of the most valuable time for work during the season was lost. Had it not been for this misfortune at least double the work would have been accomplished. The Yellow- stone Park at this time forms the most extensive unoccupied area in the West, and, surrounded by great ranges of mountains, becomes a resort for hostile bands of Indians when pursued by the troops. (xill) XIV REPORT UNITED STATES GEOLOGICAL SURVEY. To the division of the Survey in charge of Mr. Henry Gannett was intrusted the work of making a specially-detailed geological and geo- graphical survey of the Yellowstone National Park. The party was divided into two sections for the prosecution of this work; one section, consisting essentially of Mr. Gannett, topographer, and Mr. W. H. Hoimes, geologist, made the general survey of the park, while the other, consisting of Dr. A.C. Peale and Mr. J. BE. Mushbach, were oceu- pied in making detailed studies and maps of the geyser and hot-spring localities, a work of the greatest interest and value to the scientific world. Material was secured for a detailed map, on a scale of one mile to an inch, of the Yellowstone Park, an area of 3,500 square miles; and for maps on a large scale of all the principal geyser and hot-spring locali- ties. In the survey of the park, forty-seven important stations were oceupied for secondary triangulation and topography, besides a large number of lesser importance. On all the principal stations stone monu- ments were erected for future reference. Several groups of geysers and hot springs, not heretofore known, were discovered. : The area of the Yellowstone Park is, in round numbers, 3,500 square miles. Its surface is in large part level or rolling, with several groups and short ranges of mountains diversifying it. In the eastern part, extending its whole length and forming the watershed between the Yellowstone and the Bighorn, stand the rugged volcanic peaks of the Yellowstone Range. Nearly all of the park is covered with a dense growth of magnificent pine timber; indeed, west of the one hundredth meridian there is no area so densely timbered with the exception of Wash- ington Territory. The mean elevation of the park above sea-level is be- tween 7,000 and 8,000 feet, which implies too cold a chmate to admit of agriculture, except in certain very limited localities. Itis safe to say that not more than one per cent. of this area can, by any possibility, be used for agricultural purposes. Except along the northern border, graz- ing land exists only in small patches of a few acres each. There are not, so far as is known, any mines or mineral deposits within the park. The only occupied buildings within the park are at the White Mount- ain Hot Springs, where Mr. J. C. McCartney has made some improve- ments. A good wagon-road extends from Bozeman, Mont., to this point. From these springs, which form the usual point of departure for excur- sionists, there are excellent trails to all points of interest withiao this region; to Amethyst Mountain, Yellowstone Falls and Lake, the Mud Geysers, and other objects of interest on Yellowstone River and the Geyser Basins. It isunnecessary to specify these trails, as they traverse the country in all directions. In his campaign against the Nez Percés, in 18/7, General Howard constructed an excellent wagon-road up the Madison to the Lower Geyser Basin, and thence across to the Yellow- stone. His road upthe Yellowstone is impassable at present for wagons. Mr. W. H. Holmes acted as geologist to the second division. The first month of the season he was with the fourth division, which pro- REPORT UNITED STATES GEOLOGICAL SURVEY. KV eeeded from Point of Rocks Station northward, along the west side of the Wind River Mountains, and up the Snake River Valley to the Yel- lowstone Park, where he joined the second division. In the mean time he was engaged in making sketches, panoramic views, and geological sections of the intermediate country, all of which will prove of the highest importance in illustrating the geological structure of this most interesting and complicated region. The latter part of the sammer was spent in making detailed geological examinations in the district that includes the National Park. The greater portion of the park was found to be covered with somewhat uniform flows of the ordinary voleanie rocks. Features of more than ordinary geologic interest occur, however, along the northern border of the park district. Here a small belt, not more than 15 by 30 miles in extent, con- tains a fair epitome of the geology of the Rocky Mountain region. The whole series of formations from the earliest to the most recent are almost typically developed. The only marked irregularity in the succession of geologic events occurred during the great mountain-building period of the Middle Tertiary. After that followed a number of inferior oscillations of the surface, during which an extensive series of recent Tertiary and volcanic rocks were deposited. Connecting this period with the present are the deposits of a number of great lakes, which at the present time have their chief representative in Yellowstone Lake. Detailed inves- tigations were made at many points of interest, and a fine mineralogical collectien was made. In the mean time Mr. Holmes made sketches covering every square mile of the Park, an area of 3,500 square miles. In such minute detail was the work done that the economic resources, as well as all the minor features of the geology, can be laid down on a map on a scale of one mile to an inch with the greatest care and minuteness. The great variety of forms which the mountains in and around the park assume can be presented to the eye by panoramic views with wonderful distinctness. The third division, under Mr. I. A. Clark, surveyed the Wind River Mountains, a portion of the Wyoming Range, the Gros Ventre Range, with a large area in the Snake River Valley. Mr. Clark made 31 gradi- enter stations and 15 compass Stations. The area lies between latitude 43° and 44° and longitude 109° 15’ and 111°. This includes the upper portion of the Wind River Mountains, with portions of the Wyoming Kange, the Gros Ventre Range, and portions of the Shoshone Mount- ains and the Owl Creek Range; also the sources of Green River, Hoback Basin, and upper waters of Wind River. Mr. St. John acted as geolo- gist and Mr. N. W. Perry as mineralogist to this party. Their reports will prove of general interest. Mines of gold, silver, iron, and vast beds of gypsum, as well as many other minerals, were found. In the prosecution of the field-work of the Survey during the past season a photographie division was again put in operation, after an interval of two years, under the leadership of Mr. W. H. Jackson, who XVI REPORT UNITED STATES GEOLOGICAL SURVEY. | has been connected with the Survey as its photographer during the past nine years. Leaving Point of Rocks, on the Union Pacific Railroad, on July 24, the first points of interest were reached on the western flank of the Wind River Mountains. ‘Two side trips, undertaken in connection with | Mr. Wilson, in charge of the primary triangulation, were made to the crest of the range, and some grand views of that remarkable region were obtained. From the summit of Frémont’s Peak views were made of an immense glacier now occupying its eastern slope. Fine views were also obtained of the great glaciated plateau lying between the plains and the crest of the range. Proceeding next to the vicinity of the Grand Tetons, lying to the east of the headwaters of the Snake River, several magnificent views of the remarkable range in which they occur were made from the neighborhood of Jackson’s Lake. Reaching Shoshone Lake the 18th of August, the entire month follow- ‘ing was devoted exclusively to the careful photography of all the remark- able phenomena connected with the hot springs and geysers of the vari- ous basins within the Park. Especial attention was paid to the almost unknown but exceedingly interesting features of the new Shoshone and Red Mountain Basins. The “Fire Hole” and “Mammoth Hot Spring” Basins were again gone over, and the experience derived from the work done here in former years shows its benefits in the remarkably effective views obtained this season. At this latter basin many detailed as well as general views were made with especial reference to the future pro- duction of an exact model in plaster of the whole group. On the homeward route, which was by the way of the Upper Yellow- stone, across the headwaters of the Snake to the Wind River and thence via Camp Brown to the railroad, a number of: very effective views were made, particularly about the Grand Falls and the cation of the Yellow- stone. At the Yellowstone Lake some very fine views were made, but that region was left somewhat incomplete in por et sates of a prolonged snow storm. At the Togwotee Pass some characteristic views were obtained of the © remarkable breccia mountains, whose castellated forms adorn that por- tion of the continental divide, and also some of the curious “bad lands” farther down on Wind River. The season’s work closed at Camp Brown, where'some excellent portraits and groups were made of the Bannock prisoners in confinement at that post. A brief summing up of the season’s operations of three months, much of which time was characterized by extremely inclement weather, shows an increase to the already very extensive collection of the survey, of 45 negatives 11 by 14 inches in size, and 110 of smaller ones, 5 by 8. The number was purposely kept small that a better quality might prevail in them. The geologist in charge accompanied the photographie division, and — REPORT UNITED STATES GEOLOGICAL SURVEY. XVII the route pursued gave him an opportunity to secure a very accurate general knowledge of the geological structure of a large area. The Wind River Range proved one of remarkable interest. It has a trend about northwest and southeast, with a length of about 100 miles. On the west side all the sedimentary belts have been swept away, down to the Archean, older than the Wahsatch, and the latter formation rests on the Archean rocks all along the base of the range, seldom inclining more than 5° to 19°. On the east side of the range the series of sedi- mentary formations usually known to occur in the northwest are exposed from the Potsdam sandstone, which rests upon the Archean rocks, to the Cretaceous inclusive. Along thenorthwestern portion of the range the Wahsatch Group only is seen for some distance, but as we proceed down the Wind liver Valley the formations appear one after the other, until at the lower end the entire series is exposed. The Wind River Range may be regarded as originally a vast anticlinal, of which one side has been entirely denuded of the sedimentary, except the Middle Tertiary. On the same side of the range the morainal deposits and glaciated rocks are shown on a scale such as we have not known in any other portion of the West. Three genuine glaciers were discovered on the east base of Wind River and I'rémont Peaks, the first known to exist east of the Pacific coast. The morainal deposits are also found on a grand scale in the Snake River Valley, on the east side of the Teton Range. The numerous lakes have been the beds of glaciers, and the shores of the lakes are walled with morainal ridges. North of the Teton Mountains the prevailing rocks are of modern volcanic origin, and in the Yellowstone Park the hot springs and geysers are the later manifestations of the intense vol- canic activity that once existed. All these interesting features were studied with care, and the results have been elaborated for the present annual report. It was with great pleasure that the geologist in charge reviewed the ground passed over in 1860, over eighteen years previously. In the years 1859 and 1860 he acted as geologist to the exploring expedition under the command of Col. William F. Raynolds, nuw of the Engineer Corps, U.S.A. A geological map accompanies the report of the expe- dition, which embraces Dakota and Montana, with portions of Idaho, Wyoming, and Colorado. In presenting the final annual report of the field-work of the survey, it seems proper to make a brief statement in regard to the causes which led to the delay in its publication. During the season of 1878 and 1879, Congress passed a law, discontinuing the three surveys then in existence, on the 30th of June, 1879, and and establishing the United States Geol- ogical Survey. The members of the Geological Survey of the Terri- *Geological Report of the Exploration of the Yellowstone and Missouri Rivers, under the direction of Capt. (now Lieut. Col. and Brevet Brig. Gen.) W. F. Raynolds, Corps of Engineers, 1859-1860. By F. V. Hayden. “Sapam i XVIII REPORT UNITED STATES GEOLOGICAL SURVEY. tories were discharged, some remaining in Washington, having obi ned positions in various departments of the government, others engaging in business in different parts of the country. These reports were, there- fore, completed at such leisure intervals as could be spared from other duties. The great pressure of work on the Public Printing Office for several years past has also been a partial cause of delay. Of the valuable memoirs embraced in the first part of this report, but little need be said. They comprise those of White, St. John and Scudder, on geology and paleontology, and those of Packard and Shufelt on natural history, and they will be found to be of the highest interest and eminently creditable to these authors. The editorial work has been under the supervision of W. H. Holmes, who has also had general charge of the business of the survey in Wash- ington for the last two years. He has bestowed much time and labor upon the preparation and revision of illustrations as well as upon other details of the work. ; I take pleasure in acknowledging the important service of Mr. F. M. Pierson, formerly clerk of the survey, who rendered very efficient aid in closing the business affairs of the organization. During the season of 1878 and 1879, Mr. James Stevenson, performed the duties of executive officer with his usual ability and fidelity. The small appropriation which had been allowed by Congress for com- pleting the office work of the United States Geological and Geographical Survey of the Territories was exhausted June 30, 1882. Five volumes of the quarto series of publications remained unpublished though far advanced towards completion. At my request, the Secretary of the Interior confided the general direction of completion and publication of these volumes to Maj. J. W. Powell, Director of the United States Geological Survey, who has assured me that he will render every facility in his power in bringing these final reports out in creditable shape. The survey does not claim that its work is absolutely accurate in detail but rather preliminary to the more thorough study which is to come in the future. It is believed, however, that this report will be regarded as an important contribution to the geological and natural history resources of the region under examination. Very respectfully, your obedient servant. F. V. HAYDEN, United States Geologist. To the SECRETARY OF THE INTERIOR. ee, le E GEOLOGY AND PALEONTOLOGY. REPORT OF C, A. WHITE, M. D. LETTER OF TRANSMITTAL. WASHINGTON, D. C., April 7, 1880. Sir: I have the honor to herewith transmit Contributions to Inverte- brate Paleontology, Nos. 2-8, together with thirty-two pilates of illus- trations. The character of these articles is set forth in the remarks which precede each, respectively, and they have been made as complete as the circumstances attending the closing up of the affairs of the Sur- vey hitherto under your direction would allow. These articles are a portion of the series of ‘“ Contributions,” No. 1 of which appeared in the Annual Report for 1877, for which you had made provision among the publications of the Survey, in addition to the less elaborate ‘‘ Papers” and more exhaustive memoirs. While the cireum- stances referred to have rendered these articles less complete than could be desired, and less so than was originally intended, the illustration of nearly all ‘the fossil species that have been hitherto described in the publications of the Survey is an important point gained. Very respectfully, C. A. WHITE. Dr. F. V. HAYDEN, United States Geologist in Charge. CONTRIBUTIONS TO INVERTEBRATE PALEONTOLOGY, NO. 2: SC FOSSILS OF THE WESTERN STATES AND TER; By C. A. WHITE, M. D. The present article is a continuation of the one entitled Contributions to Invertebrate Paleontology, No. 1 (and bearing the same sub-title), which was published in the Annual Report of this Survey for 1877. The material upon which this article is based, like that which formed the basis of the former one just referred to, has been collected by different persons from Cretaceous strata, at different and widely-separated locali- ties in the western portion of the national domain. In connection with the establishment of this series of illustrated ar- ticles, under the general title of “‘ Contributions to Invertebrate Paleon- tology,” the hope was entertained that the subjects which they should involve might be treated philosophically and somewhat exhaustively ; and that upon those subjects some important generalizations, both stratigraphical and zodlogical, might be based. Circumstances required the publication of the former article without an opportunity for satis- factory discussion of the subjects which properly pertained to the fossil forms described and figured therein; and the abolishment by act of Congress of this Survey, as at present organized, without affording an opportunity to pursue any further studies in the field before its publi- cations must cease, makes it necessary to publish this material, as well as that of the two following articles, in a similarly unsatisfactory man- ner with that of the first. The main object of this series of articles as originally planned has therefore not been attained, but as none of the Species embraced in any of them have ever before been illustrated, an important object will have been accomplished by the illustration of so considerable a number of species as is here represented by figures of typical specimens. A part of the species embraced in this article were published in differ- ent reports of the Survey by Mr. Meek, before his death; a part of them by the writer, in the Bulletin of the Survey and the Proceedings of the National Museum; and the remainder are here published for the first time. The greater part of the fossils were collected by persons connected with this Survey, but a part of them have been sent to the office of the Survey and the National Museum by private parties. Among these are the two corals which are first noticed on the following pages, and Pinna’ lakesti, which is described on a subsequent page. These three species were included in a collection of fossils which was sent for examination to the oftice of the Survey by Mr. Arthur Lakes, who collected them from the Cretaceous strata on Fossil Creek, 16 miles westward from Greeley, and 6 miles southward from Fort Collins, Colo. These two corals present so conspicuously a Paleozoic facies that it is proper to call especial attention to their stratigraphical position. Mr. Lakes’s known 5 6 GEOLOGICAL SURVEY OF THE TERRITORIES. familiarity with the geology of that region would of itself incline me to refrain from questioning the correctness of his reference of these fossils to Cretaceous strata, notwithstanding their Paleozoic aspect; but, for- tunately, he has made such questioning impossible, by sending pieces of rock in which both the corals and well-known forms of Cretaceous mollusean shells are imbedded together. Besides this, I have myself visited that locality and made collections from its strata, some forms of which I recognize as of the same species as a part of those sent by Mr. Lakes. I also recognize the strata there as belonging to the lower por- tion of the Fox Hills Group of the Cretaceous series, as that group is developed in Colorado; and they are doubtless equivalent with a por- tion of the Fort Pierre Group, or Cretaceous No. 4, of the Upper Mis- souri River region. Remains of the Celenterata are exceedingly rare in all the Creta- ceous rocks of Western North America, and therefore the discovery in them of any coralline form is of more than ordinary interest ; but the interest concerning these two forms is greatly increased by their evident Paleozoic affinities. Being imbedded in sandstone, the condition of their preservation is not such as to give entirely satisfactory results from their study. I have therefore referred them provisionally to Pale- ozoic genera, because, in their visible characteristics, they correspond more nearly with those genera than with any others known to me. Prof. H. Alleyne Nicholson, of the University of St. Andrews, Scot- land, whose labors in the fossil Actinozoa and Polyzoa are so well known, has kindly examined specimens of both these forms at my solicitation, and to him I am indebted for valuable notes concerning them, from which J have drawn in the following remarks embraced in the deserip- tions of the species. Several years ago, while examining the conglomerate beds of the Da- kota Cretaceous Group in Western Iowa, I found among the pebbles, of which those beds are so largely composed, some fragments of Paleozoic corals. These coral-pebbles were water-worn like the others, and like them they were also siliceous. That region was traversed by the east- ern shore-line of the earlier intercontinental Cretaceous sea, the waters of swhich washed the whole series of Paleozoic strata there. The fossils of those strata, especially the corals of Devonian and Upper Silurian age, are often silicified, and they doubtless reached that condition before Cretaceous times. It is, therefore, easy to understand that the corais found in the pebble-beds referred to are really Paleozoic corals which were redeposited in Cretaceous strata, and not Cretaceous corals of Paleozoic types. The case, however, is quite different with the corals sent by Mr. Lakes from the Cretaceous strata of Northern Colorado. These corals are calcareous and not siliceous, and they are also comparatively fragile. hey present no appearance of having ever been water-worn, nor does the stratum in which they were found, an ordinary slightly calcareous and slightly muddy sandstone, contain any water-worn masses of any kind larger than the grains of coarse sand. We therefore necessarily reach the conclusion that these corals are really of Cretaceous age, although having so much the aspect of Paleozoic forms. I am indebted to the late Prof. B. F. Mudge for the types of two new forms from the Dakota Cretaceous of Kansas; and a very interesting part of the following described species have been received from the Cretaceous Strata of Texas, having been collected at different localities and for- warded by Mr. D., H. Walker, Mr. G. W. Marnoch, and Mr. 8. W. Black, wuttr. ] CRETACEOUS FOSSILS. 7 whose names are referred to in connection with the respective descrip- tions. It has not been thought necessary to rewrite, nor in many cases to - revise, the descriptions of the fossils embraced in these articles which were formerly published by Mr. Meek in the publications of this Survey ; and I have, therefore, here copied his descriptions, and, to a great ex- tent, tacitly followed his classification. ACTINOZOA. Genus CHAXTETES Fischer. CHATETES ?? DIMISSUS White. Plate 12, fig. 14 a. Cheetetes ?? dimissus White, 1879, Bull. U. S. Geol. Sur. Terr., vol. v, p. 220. Corallum ramose, dichotomously branching at irregular intervals; branches cylindrical or subcylindrical, solid, the successive branches diminishing in. size; corallites small, not exceeding 4+ millimeter in diameter, closely compacted together, diverging from the axis of the corallum at an acute angle with it, and describing a slight upward curve as they are projected towards the surface. Character of the surface and of the corallites unknown, the specimens being firmly imbedded in sand- stone. One corallum, at least, seems to have consisted of a central or basal mass, from which several stems diverged irregularly, each stem bearing several branches. Diameter of the stems and branches varying from 2 millimeters to 6 millimeters. While this coral has all the outward appearance, and apparently the general structure, of the ramose forms of Chetetes or Monticulipora the corallites seem to be entirely destitute of tabula, even when viewed under the microscope in the section prepared for that purpose by Profes- sor Nicholson. Ifthe tabule are really absent, as they appear to be, this coral cannot be properly referred to Chotetes, nor to any other form of the Actinozoa, but it probably belongs to the Polyzoa. If it really be- longs to the latter class, I do not know any genus to which it can be referred; and as the specimens are not sufficiently perfect to warrant a new generic diagnosis, I assign them provisionally to Chetetes. Only two examples of this coral have been discovered, and, like all other coralline forms in the Cretaceous rocks of the West, it is doubtless arare one. The rarity of the remains of Celenterata in those rocks is no doubt due, not to a universal suppression at that time of those forms of life, but to the local or regional physical conditions which prevailed at the time those Western North American strata were deposited. It is a well-known fact that coral polyps require pure waters for vigorous and abundant growth; and as the Cretaceous strata of the West consist so largely of sand, it is evident that the waters in which they were deposited could not have been congenial for a large development of any of the forms of Ceelenterate life. Position and locality.—Strata of the Fox Hills Group, of the Cretaceous series, at Fossil Ridge, 16 miles westward from Greeley, and 6 miles southward from Fort Collins, Colo., where it is associated with the coral next described, and also with various Cretaceous molluscan forms. 8 GEOLOGICAL SURVEY OF THE TERRITORIES. Genus BEAUMONTIA Edwards & Haime. BEAUMONTIA ? SOLITARIA (Sp. NOv.). Plate 12, figs. 13 a, b, and c¢. Beaumontia ? solitaria White, 1879, Bull. U. 8. Geol. Sur. Terr., vol. v, p. 221. Corallum massive, compact; corallites prismatic, readily cleaving from each other in the specimens discovered, unequal in size and also in the shape of the transverse section, some of them being more than twice as large as others, and the longer diameter of some being more than twice as great as the short diameter of thesame; average diameter of the corallites not exceeding one millimeter; their walls thin, appar- ently marked only by the ordinary lines of growth; tabule plain, numer- ous, variously flexed, but never to a great degree. No trace of radiate septa or of longitudinal striation of the corallites has been detected. This coral much resembles Favosites in the character of the corallum and the aspect of the corallites, but no traces of mural pores have been detected, not even in the section prepared by Professor Nicholson, when viewed under the microscope. In consequence of this, and of the irregu- lar or flexed character of the tabule, I refer it to Beaumontia. Appar- ently the only known fact that suggests a doubt of the correctness of such a reference is that Beawmontia has hitherto been known only in Paleozoic rocks. This is also a rare form, and doubtless so for the reasons explained in connection with the description of the foregoing species. Position and locality—Associated with the preceding and various molluscan forms in Cretaceous strata of the Fox Hills Group, Northern Colorado. ECHINODERMATA. Genus OPHIODERMA. OPHIODERMA? BRIDGERENSIS Meek. Plate 12, fig. 12 a. Ophioderma? bridgerensis Meek, 1873, An. Rep. U. S. Geol. Sur. Terr. for 1872, p- 475. The type specimen from which Mr. Meek drew his description, and from which the figure on plate 12 is drawn, is the only example of the species that, has ever been discovered. Therefore nothing more is known of it than was published (loc. cit.) by Mr. Meek. It was obtained by one of the parties of the Survey from the “last foot of Bridger Peak, 4 miles north of Fort Ellis, Mont.,” where it is reported to be associated with certain imperfect molluscan remains, among which Mr. Meek recognized the following genera, namely: Gryphea, Avicula, Pinna, Inoceramus, Crassatella, Pholadomya, Turritella, and Gyrodes. The following is Mr. Meek’s brief deseription: “A small Ophiuran, with disk depressed, nearly circular, and only 0.17 inch in breadth, showing on the dorsal side ten ovate-subtrigonal radial plates that are joined together over the inner ends of the arms, so as to form five pairs; arms small, only about 0.75 inch in length, and at their inner ends 0.06 inch in breadth; middle row of arm-pieces on the dorsal side slightly wider than long, and hexagonal in form; marginal pieces about as large as the middle ones, WHITE.] CRETACEOUS FOSSILS. 9 seen somewhat edgewise from above, and bearing a row of very small short spines. Ventral side unknown. The specimen is not well pre- served ; perhaps I should call it Ophiolepis bridgerensis.” CONCHIFERA. Genus OSTREA Linneeus. OSTREA SOLENISCUS Meek. Plate 11, figs. 2 a and b. Ostrea soleniscus Meek, 1873, An. Rep. U. 8S. Geol. Sur. Terr. for 1872, p. 487. The name of this species was given by Mr. Meek in a catalogue of fos- sils, on page 276 of the Annual Report of this Survey for 1871, but as no description or diagnosis then accompanied it, the name can date only from 1873, when his description was first published (loc. cit.). The following is Mr. Meek’s diagnosis of the species, together with his remarks upon it: “Shell attaining a large size, becoming rather thick in adult ex- amples, generally straight, greatly elongated, and comparatively very narrow, with parallel lateral margins. Lower valve with moderate internal cavity, and having the appearance of a little gutter or elon- gated trough; beak usually nearly straight, rather obtusely pointed, and more or less distorted by the scar of attachment; ligament-area of moderate size, strongly striated transversely, and provided with a large, deep, longitudinal furrow; surface apparently only with moderately dis- tinct marks of growth. Upper valve almost flat externally, but nearly as concave as the other within; beak usually a little truncated; ligament- area marked with strong transverse strive, and having its mesial ridge very prominent, and occupying as much as one-third its breadth. Sur- face as in the other valve, or perhaps a little smoother. “Length of adult examples about 18 inches; breadth of the same about 2.50 to 3 inches. “Although not a very uncommon species, I have seen no entire speci- mens of this remarkable shell. It will be readily known by its unusu- ally narrow, elongated, and generally straight form. The shell is usually found broken into several pieces, but casts of the internal cavity are not unfrequently met with entire. One of these now before me is nearly one foot in length and only two inches in breadth. It often had a curi- ous habit of growing in groups of three shells, attached to each other by the backs of their beaks. I have seen large numbers of them closely arranged, or nearly in contact with each other, at Coalville, all with their beaks downward, or at right angles to the plane of the sandstone strata. When found where it has grown isolated, the shell is sometimes arched to one side. “Tocality and position.—This species ranges through nearly the whole thickness of the Cretaceous sandstones near Coalville, Utah, and is also found in the Cretaceous coal-bearing sandstones at Bear River City, Wyo., as well as in the sandstone ridge of the same age on the Union Pacific Railroad, a few miles east of the latter locality.” I have frequently collected specimens of this species in the region in- dicated by Mr. Meek, and have verified all his observations as given above, but no specimens more perfect than his types have ever been dis- covered. While a large majority of the specimens have the long slender 10 GEOLOGICAL SURVEY OF THE TERRITORIES. form described by Mr. Meek, there are many also which are not so much elongated, but which are evidently of the same species. This remark applies not only to the young, which were proportionally short, as shown by the lines of growth upon the anterior portion of adult shells, but also to many that are massive and evidently of adult growth. SjAill, the spe- cies has always much more than the average proportionate length. The habit of this oyster, mentioned by Mr. Meek, of uniting its shells in groups of three, by their deeper valves, is not confined to this species alone. I have often observed it in the case of O. glabra M. & H. of the Laramie Group. I suppose it to have been a not uncommon habit with oysters that-lived on sandy bottoms, because, in all the cases I have ob- served, the specimens were collected from soft sandstone strata; and yet in all these cases the majority of their associates of the same species were free. It is a common habit with oysters to attach themselves to- gether, but why they should so often have been attached together in the manner described is not easy to understand. Considerable variation in form is very common in all species of Ostrea proper, and some very elongate examples of the living O. virginica are occasionally brought into the markets from various places along the At- lantic coast. This fact was illustrated by a large labeled series pre- pared at the Smithsonian Institution by Mr. W. H. Dall for the Centen- nial Exposition in 1876. In reply to some inquiries, Mr. Dall writes me: “In the ease of O. virginica there is no doubt that a position where it is subjected to currents, and especially if the water carries a little sediment, will induce a long, thin growth, with parallel sides; while still waters tend to produce a rounded form. The normal is between the two. But there are normally long species and normally round, besides twig-climb- ing species, all of which, in a state of nature, may be differently affected from thinned and planted oysters.” There is no room for doubt that Ostrea soleniscus is a normally long and slender species. That its elongate form is not due to the same cause which elongates the specimens of O. virginica before referred to is Shown by the fact that so many of the longest of them are found in a vertical position, evidently their natural one, in relation to the plane of the strata containing them, as mentioned by Mr. Meek, and also observed by my- self. It is also contra-indicated by the fact that so many of them grew in clusters of three, attached together by their larger valves, and by the absence of any evidence in the character of the strata that they were de- posited in water having a current of sufficient strength to produce such a result. I know of no other American oyster, either fossil or recent, that need be confounded with this species The anterior portions of many of the specimens, as they are often found broken off, resemble corresponding portions of O. longirostris Lamarck, as figured by Goldfuss; but although that species is an elongate one, O. soleniscus is constantly a much more slender species. OSTREA ANOMIOIDES Meek. Plate 11, figs. 4a and 0. Ostrea anomioides Meck, 1873, An. Rep. U. S. Geol. Sur. Terr. for 1872, p. 488. No other examples of this species besides those of the original collec- tion have ever been obtained. The figures on plate 11 are drawn from Mr. Meek’s types, and the following is his description of the species, together with his remarks upon it: ‘Shell rather small, very thin, depressed-plano-convex, and without WUITE.] CRETACEOUS FOSSILS. 11 any visible scar of attachment, varying from ovate to circular; rounded or sometimes a little straightened on. the hinge-margin; beaks hardly projecting beyond the outline of the cardinal margin. Lower valve very shallow; cartilage-pit unusually small, shallow, and short. Upper valve almost perfectly flat; cartilage attachment even shorter than that of the other valve, and slightly convex on its inner margin. Muscular scars unknown; surface of both valves with small, regular concentric wrinkles most distinctly marked on the central region. “‘ Greatest diameter of one of the largest oval specimens, 1.70 inches; breadth, 1.40 inches; convexity, 0.23 inch. ‘This species is remarkable for the thinness of the shell, the slight convexity of the under valve, and the flatness of the upper, as well as for its rounded or slightly straightened cardinal margin, and the absence of any scar of attachment, or of any traces of muscular impressions within. These external characters, and.the regular small concentric wrinkles, give the exterior of lower valves of circular specimens some- what the appearance of a Lucina or Dosinia, while in other individuals it looks more like an Anomia or Placuna. “Locality and position.—Missouri River, below Gallatin City, Mont. Cretaceous.” The comparative smoothness of these shells is so unusual with mature shells of any of the Ostreide as to suggest the possibility that they are immature examples; but their considerable abundance, and the nearly uniform size of all the specimens, seems to indicate that they are adult shells. If so, they evidently do not belong to the typical section of the genus Ostrea; but without some knowledge of the character of the mus- cular markings, it is unprofitable to offer any suggestions as to their true generic affinities. Subgenus ALECTRYONTA Fischer: OSTREA (ALECTRYONIA) BLACKII White. Plate 14, figs. 1a and b; and Plate 17, fig. 4a. Ostrea blackii White, May, 1880, Proc. U. S. National Museum, vol. ii, p. 293. Shell irregularly subovate in marginal outline, moderately capacious; beaks small, sometimes obscure and sometimes moderately prominent, pointing a little backward, but not conspicuously so. Lower valve usually moderately deep and capacious, its convexity being more prom- inent about the middle than elsewhere, often subalate, but the latter feature is usually obscure; scar of attachment at the beak usually present, and often moderately large; ligament-area usually short and rather small, but sometimes comparatively large and laterally extended; ligament-furrow well defined, and of the usual character. Upper valve nearly flat, and corresponding with the lower in other respects, except that it is not so broad at the hinge border, and never has there the subalations which sometimes mark the lower valve. The adductor scars are moderately large, and of the form common to Alectryenia, namely, curved-spatulate. Surface of both valves marked by concentric lines and strong imbrications of growth, and each by a dozen or more radi- ating ribs or plications, which constitute a conspicuous feature of the Shell, but they are usually somewhat less distinct upon the upper than upon the lower valve. Length, 68 millimeters; greatest breadth, 62 miliimeters; thickness, 32 millimeters. 12 GEOLOGICAL SURVEY OF THE TERRITORIES. In form and general aspect this shell approaches that of a typical Ostrea, but in the character of its adductor scars, the extent of its plica- tions, and the subalation of its cardinal border, it is properly referable to the section Alectryonia. The only shell with which it need be com- pared is that of O. bellaplicata Shumard, also from Texas. It differs from that shell in being constantly larger, proportionally less capacious, broader towards the base, and in having its hinge-border longer and more oblique. Locality and position.—Cretaceous strata, Collin County, Texas, where it was collected by Mr. 8S. W. Black, and sent by him to the Smithsonian Institution. The specific name is given in his honor. Genus EXOGYRA Say. EXOGYRA WINCHELLI White. Plate 13, figs. 1a, b, ¢, and d. Exogyra winchelli White, May, 1880, Proc. U. S. National Museum, vol. ii, p. 294. Shell of medium size, irregularly subovate in marginal outline; sessile, or attached by a.large part of the surface of the lower or left valve, be- ing obliquely inclined so that the anterior border is very much higher ° than the posterior. Lower valve massive, moderately deep, its front side nearly perpendicular and of considerable height vertically; umbo ver- tically flattened continuously with the front side, and broadly curving backward; beak closely incurved under the posterior border and con- cealed; ligamental groove long and narrow, occupying the whole curva- ture of the umbo. Upper valve nearly flat, thick, the anterior part be- — ing much thicker than the posterior; beak vertically thin or compressed, closely coiled in a plane with that of the valve, making a little more than one entire volution. Surface marked by coarse lines of growth, and, near the anterior borders of both valves, especially the upper, it is usually deeply laciniate. . Length, 90 millimeters; breadth, 66 millimeters; height in front, 55 millimeters. This species belongs to the same section of the genus Hxogyra with EH. haliotoidea Sowerly sp. and H. walkert White. The latter species is larger and proportionally broader than H. winchelli and not properly sessile, as the latter species is. H. haliotoidea, as figured by d’ Orbigny in Pal. Franeaise, t. iii, pl. 478, differs from 2. winchelli in being propor- tionally higher in front and narrower in transverse diameter, and in not having the beak so much ineurved. LH. interrupta Conrad, from Missis- Sippi, also belongs to the same section, but that species is described as having radiating ribs, which H. winchelli has not. Position and locality.— Cretaceous strata, Collin County, Texas, where it was collected and sent to the Smithsonian Institution by Mr. 8. W. Black. The collections of the Institution also contain a fine example sent by Prof. A. Winchell many years ago from Prairie Bluffs, Ala., which is believed to be specifically identical with the form here described, but it is proportionally more elongate, has a larger muscular scar, and the umbonal curve is a little more abrupt. The specific name is given in honor of Professor Winchell. WHITE.] CRETACEOUS FOSSILS. 13 EXOGYRA FORNICULATA White. Plate 14, figs. 2a and b. Gryphea pitchert Marcou, 1858 (not Morton), Geol. of N. A., pl. iv, figs. 5 and 6. Gryphea navia Gabb, 1861 (not Conrad), Proc. Acad. Nat. Sci. Philad., p. 22; ib., Paleont. California, vol. ii, p. 2738. Exogyra forniculata White, May, 1880, Proc. U. S. National Museum, vol. ii, p. 293. Shell of moderate size, subtrihedral in lateral outline, somewhat com- pressed vertically; under or left valve thick, especially its umbonal half; beak curved strongly towards the posterior border and in the plane of the free margins of the valve, not forming so much as one complete volution, its point being free but closely approaching the posterior bor- der of the valve; ligament-area irregularly triangular, moderately large, extending to the apex of the beak, its sulcus well developed; interior surface having the usual characteristics of the genus. A faint, illy-de- fined sulcus is apparent on the posterior portion of the surface, extend- ing from the umbo to the basal border, between which sulcus and the laterally flattened-concave posterior border of the valve there is an equally indefined radiating curved ridge. The anterior portion of the valve is marked by a strong, angular, rough carina, or ridge, which ex- tends from the beak to the basal border. The prominence of this ridge gives a flattened aspect to the outer surface of the valve and also pro- duces a flattened space of considerable width between it and the an- terior margin. Surface marked by the ordinary coarse lines and imbri- cations of grewth common to the Ostreide, and upon the ridge just described there are occasional nodes, or vaulted projections of portions of the shell. Upper vaive flattened and having much the aspect of that of a Gryphea. Length, 70 millimeters; breadth across the base, where it is widest, 50 millimeters. This shell is much like a Gryphcea in general aspect, but it is referred to Exogyra because of its laterally-curved umbo and beak. It is often difficult to point out clear distinctions between these two genera, but the lateral curvature of the beak appears to be the most constant and im- portant characteristic of Hxogyra, distinguishing it from Gryphea. Spe- cifically, this shell is well marked by the strong, rough, angular carina, its free beak, narrow umbonal region, and broad base. In these respects it differs too much from any described species except a variety of Gryp- hea pitcheri, to make detailed comparison necessary. Morton’s Gryphea pitcheri has, unfortunately, been the cause of much controversy among paleontologists, in which the species here described has been involved because of some general resemblance which it bears to some varieties of the former. It is not my purpose to add anything to that controversy, but to endeavor, by the following remarks, to free Hxogyra forniculata from necessary connection with it. Professor Marcou (loc. cit.) referred this species to G. pitcheri, and gave excellent figures of it, but it differs materially from any of the sev- eral varieties of G. pitcheri in (not to mention other features) the invari- able lateral deflection of the beak. If Gryphwa be distinct from Hxogyra, then this is a generic character; and, in any case, it is at least a strong specific one, aud one which is constant and readily recognizable. Mr. Gabb (loc. cit.) referred this species to G. navia Conrad; and on p. 274 of the last-cited work he gave a new name, G. mucronata, to the true G. navia, or to a form that its author cited as such. Mr. Conrad 14 GEOLOGICAL SURVEY OF THE TERRITORIES. appears never to have known F. forniculata. His original figures, in Emory’s Mex. Bound. Report, of G. navia, which he properly regarded as only a variety of G. pitchert, are unmistakable in their identity, and illus- trate a well-known torm which, although in a general way resembling, is distinctly different from EL. forniculata. Besides this, Mr. Conrad, in his accompanying description, refers, as already intimated, to Roemer’s figures in Kreid. von Texas, pl. ix, fig. 1 a, b, and ¢, as excellent repre- sentations of his G@. navia, which are also very different from H. fornicu- lata in their long vertically arched beaks. Mr. Gabb also refers to those figures of Reemer as illustrations of his G. mucronata ; and there is, there- fore, no room for doubt as to the mutual identity of the forms to which these two names were respectively applied by Mr. Conrad and Mr. Gabb. The latter author discriminated correctly between the true G. navia, as represented by Conrad’s and Roemer’s figures respectively, and H. for- niculata, and he possibly intended to give a new name to the latter form instead of the former; but he did not, and the latter has gone without a correctly-applied name until I published it as H#. forniculata in Proc. U.S. Nat. Museum, vol. ii, p. 293. Position and locality—Cretaceous strata, Bexar County, Texas, where it was collected by G. W. Marnoch, esq., together with many well-known Cretaceous species of that region. It is also found at numerous other Texan localities. Genus ANOMIA Linneeus. ANOMIA PROPATORIS (Sp. nov). Plate 12, figs 15 a and b. Shell rather small, irregularly and a little obliquely subovate or sub- circular in marginal outline; test pearlaceous and moderately thin, as is usual-in Anomia. Upper valve convex; beak small, depressed, not quite marginal; surface marked by somewhat coarse, irregular wrinkles of growth, by a few radiating wrinkles in the umbonal region, and by fine, close-set, raised, radiating strie, the latter appearing more distinctly on the forward part of the shell than elsewhere. Under valve unknown. Length of the most perfect example in the collection, 11 millimeters ; breadth, 10 millimeters; convexity, 5 millimeters. ‘i This shell resembles A.gryphorhynchus Meek, the typical examples of which are from the Laramie strata of the Bitter Creek series, Southern Wyoming, but it differs from that species in having aless prominent and rounded umbo; in possessing radiating and concentric wrinkles and radiating raised striee, while that species is an unusually smooth one. In the possession of the radiating raised striz it corresponds closely with A. micronema Meek, which is so commonly distributed throughout the Laramie Group. As this striation constitutes a more important characteristic than mere form, which is always variable in this genus, it strongly suggests an intimate genetic relation for our shell with A. micronemd. This species is a member of the estuary fauna which was discovered several years ago by Mr. Meek in the Cretaceous series of strata at Coalville, Utah, and which is more particularly mentioned on a subse- quent page, in remarks which follow the description of Cyrena carletont. Although all the species of that Cretaceous estuary fauna are different from any yet found in the Laramie Group, several of them are so closely related to certain Laramie forms as to strongly suggest the idea that WHITE.] CRETACEOUS FOSSILS. 15 the molluscan fauna of the Laramie period had mainly its genetic derivation from the estuary faunz that were established along the con- tinental shores of marine waters during the previous Cretaceous epochs. In view of what we already know of the history of the great Laramie deposit, this view of the genetic derivation of its molluscan fauna would seem to be the most natural one, even without the paleontological hints here mentioned. In the marine strata of the Cretaceous series at Coalville examples of an Anomia are not unfrequently met with which closely resemble this one, and which may really belong to the same species. All the examples from the marine strata there which have come under my observation are, however, too imperfect to show the surface markings, and thus an important specific characteristic is wanting. Position and locality.—The specimen figured on plate 12 is one which Mr. Meek obtained from the estuary strata of the Cretaceous series at Coalville, Utah. Genus PTERIA Scopoli. PTERIA?? STABILITATIS (sp. NOv.). Plate 17, fig. 3 a. Shell adherent by the whole surface of the right valve, suborbicular or transversely suboval in marginal outline; hinge-line straight, less in length than the breadth of the shell. Right valve thin, especially at, and near the margins; beak minute, hardly raised above the cardinal border; ears minute or obsolete; hinge-area narrow, ending somewhat acutely both anteriorly and poster iorly, its Inner border prominent but plain; cartilage-pit small, pyramidal, turned obliquely forward. Upper or right valve unknown. Breadth of the largest example discovered, 34 millimeters ; height of the same from base to cardinal border, 26 millimeters. Three or four of the examples are not above 14 millimeters in diameter. The only known representatives of this species are one adult and sev- eral small examples of the right valve adhering to the surface of a frag- ment of the shell of a large Inoceramus. It evidently belongs to the Aviculide, but in being adherent by the whole surface of the right valve it differs from all other known members of that family, and when perfect examples of both valves are discovered it will probably be found to rep- resent an unpublished genus. The shell-substance of the thin marginal portion of ajl these examples is loosely cellular, which condition is pos- sibly due to some malady which affected the mollusk while living, but it seems to be connected with a prismatic-cellular structure of the thicker portion, such as is common to the Aviculide. Position and locality.—Cretaceous strata, Collin County, Texas, where it was collected by Mr. 8. W. Black, and sent by him to the Smithsonian Institution. Subgenus OXYTOMA Meek. PTERIA (OXYTOMA) SALINENSIS White. Plate 16, figs. 2 a and DB. Pteria (Oxytoma) salinensis White, May, 1880, Proc. U. S. National Museum, vol. ii, p. 296. Shell rather large for a Cretaceous Pteria; the body, exclusive of the wings, being obliquely ae knead broad at base, moderately gibbous, dis- 16 GEOLOGICAL SURVEY OF THE TERRITORIES. tinctly but not very greatly inequivalve; the left valve, as usual, more convex than the right, and its beak more prominent than the other; the convexity of the surface of the valves somewhat uniform, but increas- ing toward the umbonal region, where it is greatest; anterior wing mod- erately large, defined from the body of the shell by being laterally com- pressed, but not by any distinct auricular furrow; the byssal sinus under the anterior wing of the right valve having the usual size and shape common to Oxytoma; posterior wing not proportionally large, and not distinetly defined from the body of the shell except by a somewhat grad- ual lateral compression; its posterior angle not greatly produced ; hinge- line less than the axial length of the shell; posterior adductor scars not distinct; anterior scars distinct for a shell of this genus, placed imme- diately in front of the beaks, that of the left valve being more distinct than the other. : This, like the following described species, is known only from natural casts in brown hematite of the interior of the shell, the imperfection of which will not allow of an accurate measurement of all its proportions. It is, however, known to have reached an axial length of more than 60 millimeters, a transverse width near its base of at least 50 millimeters, and a thickness of about 25 millimeters, when both valves were in natural position. The character of the surface is not known, but it was evidently nearly smooth, as is usual with its congeners. Itis related to Pteria (Oxytoma) nebrascana Evans & Shumard, but it is a larger and more robust shell, having a proportionally larger anterior wing, more prominent beaks, and broader base. Position and locality—Strata of the Dakota Group, Saline County, Kansas, where it was discovered by Prof. B. F. Mudge, associated with the next following described species, and also with Cyrena dakotaensis Meek & Hayden and Cardium kansasense Meek. Genus GERVILLIA Defrance. GERVILLIA MUDGEANA White. Plate 14, figs. 3 a and b. Gervillia mudgeana White, May, 1880, Proc. U. S. National Museum, vol. ii, p. 295. This shell, like the last described, is known only from natural casts in brown hematite of the interior and of a few adhering fragments showing the character of the test. It is moderately large, laterally distorted ; hinge-line comparatively long, very oblique with the axis of the shell, producing a somewhat prominent posterior alation, which is not dis- tinctly defined from the body of the shell; cartilage-pits in the area of each valve six or seven, as shown by undulations upon the cast; beaks placed very near the anterior end, beyond which there appears to have been no distinct anterior ear; beak of the right valve more prominent than the other, although the right valve is less convex transversely than the left; right valve having a somewhat regular and strong longitudinal convexity, but its transverse convexity is very slight in the anterior half, while that of its posterior half is nearly flat; left valve nearly straight or even Slightly concave longitudinally along the axis, but very strongly convex transversely in all parts, this convexity being more abrupt along the axis than elsewhere, but there is between the axis and the hinge- margin a slightly raised rounded fold which extends from behind the beak to the posterior margin; adductor muscular impression large and waurr.| CRETACEOUS FOSSILS. 17 distinct in each valve. A few fragments show the surface to have been marked by the ordinary concentric lines of growth, and also that the test, although firm, was not massive. The dimensions cannot be definitely given, but the largest example discovered indicates a length of at least 80 millimeters. This shell differs too much from any of the few known Cretaceous spe- cies of the genus to need detailed comparison, but it is related to G. sub- tortuosa Meek & Hayden, which it resembles in being tortuous., It differs, however, from that species in being a proportionally much shorter shell, in the shape and position of the adductor scars, and in the relative position and arrangement of the cartilage-pits. It is less tortuous than G. tortwosa Sowerby, and its proportions are different. Position and locality—Strata of the Dakota Group, Saline County, Kansas, where it was discovered, associated with the preceding species, by Prof. B. I’. Mudge, in whose honor the specific name is given. Genus PINNA Linneus. PINNA LAKESII White. Plate 11, figs. 1 a and D. _ Pinna lakesti White, 1879. An. Rep. U.S. Geol. Sur. Terr. for 1877, p. 181. Compare with Pinna restituta Heeninghaus. Shell rather large, slender anteriorly but beeoming quite broad ae somewhat compressed posteriorly; sides not angular or otherwise con- spicuously marked along the median line, nor very convex except near the anterior end, where the transverse thickness of the shellis about equal to its height from base to dorsal border; dorsal margin broadly concave from front to rear and longer than the basal margin ; posterior border convex, or rather truncated obliquely downward and a little back- ward from the dorsal border toa point a little below the median line, where it is abruptly rounded, and, by a long forward slope, blends with the basal border, which border is slightly convex or nearly straight. Surface marked by the usual lines of growth and by some concentric wrinkles, which latter are more distinct below than above the median line. It is further marked by numerous slender, slightly raised, radiating ribs, which extend continuously from the anterior to the posterior end of the shell. Seven or eight of these ribs mark the whole space above the median line, and three or four are seen below it, leaving the lower half of the space below the median line free from ribs. The ribs are merely close-set raised lines upon the narrow front end of the shell but become stronger farther backward. They are there much narrower than the intervening spaces, because the width of the latter increases posteriorly much more rapidly than that of the ribs. Full length of the specimen figured on plate 11, about 280 millimeters ; width (vertical) of the same at the widest part, about 83 millimeters. This species is in no danger of being coufounded with any other described and figured form from American rocks, but it somewhat re- sembles the P. decussata Hoeninghaus as figured by Goldfuss. It differs from that species, however, by increasing more rapidly in size from front to rear, by the much less convexity of its basal margin, and by the char- acter and direction of the posterior and postero-basal borders as de- scribed above. Position and locality.—No examples of this species have been satisfac- torily identified from any other region than that of Northern Colorado, Pagal 18 GEOLOGICAL SURVEY OF THE TERRITORIES. east of the Rocky Mountains. The type specimens were obtained from Fossil Ridge, about 16 miles westward from Greeley, and about 6 miles southward from Fort Collins, Col. The best examples yet discovered, one of which is figured on plate 11, were obtained at that locality by Mr. A. Lakes, by whom they have since been sent to Princeton College, New Jersey. Genus VOLSELLA Scopoli. Subgenus BRACHYDONTES Swainson. VOLSELLA (BRACHYDONTES) MULTILINIGERA Meek, Plate 11, fig. 3 a. Modiola bs Meek (not Remer), 1871, An. Rep. U. 8S. Geol. Sur. Terr. for 1870, Dp. 207. Modiola (Brachydontes) multilinigera Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, p. 492. In a catalogue of Cretaceous fossils, published in the Annual Report of this Survey for 1870, Mr. Meek (loc. cit.) referred this species to the Modiola pedernalis of Roemer, but he afterward gave it the new specific name as above, together with the following description and remarks : ‘‘ Shell rather above medium size, obliquely arcuate-subovate ; valves strongly convex along the umbonal slopes, thence cuneate posteriorly and abruptly curved inward below the middle in front; posterior margin ‘forming a broad, regular convex curve from the end of the hinge down- ward to the anterior basal extremity, which is very narrowly and ab- ruptly rounded; anterior margin ranging obliquely backward and down- ward to the narrow basal extremity, and strongly sinuous along the middle, above which it projects more or less beyond the umbonail ridge, so as to form a moderately prominent, somewhat compressed, protuber- ance; hinge margin nearly or quite straight, ranging at an angle of 50° or 60° above an imaginary line drawn from the beaks to the most prom- inent part of the basal outline, and equaling about one-half the greatest oblique length of the valves; beaks nearly terminal, rather compressed, very oblique, and scarcely rising above the hinge margin; umbonal slopes prominent and more or less strongly arcuate. Surface ornamented with fine lines of growth, crossed by regular radiating lines that are very fine and crowded on the anterior part of the valves, but become coarser above and behind the umbonal ridge, the largest being near the dorsal side, where they bifurcate so as to become very fine, and curve more or less upward before reaching the cardinal margin. ‘Greatest length, measuring from the beaks obliquely to the most prominent part of the basal margin of a large specimen, 1.90 inches ; greatest breadth at right angles to the same, 1 ineh; convexity, 0.76 inch. ‘““On first examining some imperfect casts of this shell brought by Dr. Hayden from near Coalville, Utah, I was led to think it probably the form described by Dr. Roemer from Texas under the name Modiola pedernalis, to which I referred it provisionally in making out the list of Cretaceous fossils for Dr. Hayden’s report for 1870. Further compari- sons of better specimens collected at the same locality during the past summer, however, have satisfied me that it presents well-marked and constant differences from the Texas shell. In the first place it is dis- tinctly more arcuate, so much so that when placed with its hinge line in a horizontal position, the outline of its posterior margin, instead of form- WHITE.) . CRETACEOUS FOSSILS. 19 ing an oblique, backward-descending curve, ranges nearly vertically. Again, the most prominent part of its posterior basal margin is very narrowly rounded, instead of forming a regular curve. Its umbonal ridges are likewise more prominent, more arched, and extend down to the narrowly-rounded posterior-basal extremity. The lobe-like projec- tion of the upper part of its anterior margin, under the beaks and in front of the umbonal ridge, also differs in being proportionally much smaller than in Dr. Reemer’s species, in which it forms about one-third of the entire valve, aS seen in side view, while in our shell it scarcely forms more than one-sixth. Of course the specimens are more or less variable in these characters, but the two forms can always be readily distinguished when good examples can be had for comparison. ‘¢ In its more arcuate form our shell agrees more nearly with Jfodiola ornata Gabb, from the Cretaceous rocks of California; but that shell differs very markedly in having its beaks decidedly less nearly terminal, and a more decided and much more prominent lobe in front of them. Another important difference is to be observed in the radiating strie, which on the anterior side of our shell are very minute and closely crowded, while on that part of Mr. Gabb’s species they are as large and distant from each other as on any other part of the valves. “If Scopoli’s name, Volsella, should be adopted for this genus, as there are some reasons for believing may be the case, this change would re- quire the name of this species to be written Volsella multilinigera. “ Locality and position.—Cretaceous sandstones near Coalville, Utah.” Genus BARBATIA Gray. BARBATIA BARBULATA (sp. NOV.). Plate 11, fig. 5 a. Shell small, longitudinally oblong or subrhomboidal, a little more than twice as long as high; cardinal and basal margins nearly parallel, the former straight and the latter nearly so; anterior side short, rounded up obliquely from the base, and meeting the cardinal margin at an obtuse or bluntly rounded angle; posterior side, long; posterior margin, trun- cate obliquely downward and backward from the cardinal margin to the base, which it meets at a blunted angle, or it is there abruptly rounded ; beaks distinct, but somewhat depressed and incurved, placed about one- fifth the length of the shell from the front; cardinal area narrow, but it is not well shown in our examples. Surface showing fine crowded, raised, rounded, radiating striz, which are crossed by fine lines of growth and also by numerous sharply raised concentric lines, some of which are more conspicuous than the radiating lines. Length, about 25 millimeters; height, about 114 millimeters. Only two or three imperfect examples of this species have been dis- covered, but in its shape and surface markings it presents such differ- ences from any known form as to warrant the foregoing description under a@ new specific name. Position and locality. Cretaceous strata, apparently of the age of the Fox Hills Group, at Cimarron, New Mexico, where it was found by Prof. St. John, associated with Crassctella cimarronensis White, and other forms, some of which were described and figured in Contributions to Invertebrate Paleontology No. 1, and published in the Annual Report of this Survey for 1877. 2() GEOLOGICAL SURVEY OF THE TERRITORIES. Genus CYRENA Lamarck. CYRENA CARLETONI Meek. Plate 12, figs. 16 a and 6b. Cyrena carletoni Meek, 1873, An. Rep., U. 8. Geol. Sur. Terr. for 1872, p. 495. The following is Mr. Meek’s description of this interesting species, together with his remarks upon it: “Shell small, thin, subeircular or with length a little greater than the height, moderately convex; anterior and posterior margins rounded from above "regularly into the Younded basal outline, or with the posterior sometimes slightly straightened, both rounding more abruptly to the hinge above; beaks rather depressed, small, abruptly pointed, incurved, nearly contiguous, and placed slightly in advance of the middle; hinge line sloping very eradually from the beaks. Surface marked with moderately distinct concentric lines and furrows. ‘‘Length of a medium-sized specimen, 0.55 inch; height of same, 0.49 inch; convexity, 0.52 inch. “This shell is so very thin, and so nearly resembles a rather large Spherium in form and surface characters that I certainly should have referred it to that genus had not a lucky blow separated the hinge of a right valve from the matrix in such a manner as to expose the teeth quite satisfactorily. This shows its hinge to have the characters of a true Cyrena. For so thin a shell it has quite a stout hinge. Its cardinal teeth are rather diverging, the posterior two being well developed, and each a little furrowed along the middle, while the anterior one (in this right valve) is much smaller and conical in form. The lateral teeth are of moderate size, and certainly smooth, the posterior being remote from the cardinal teeth, and the linear anterior extending back to the latter. Internal casts show the muscular and pallial impressions to be well de- fined, and the latter to be a little straightened, or showing a very faint tendency to form a small sinus under the posteri i0r (adductor scar). “This is a rather small and an unusually thin shell for the genus Cyrena, being, as already remarked, much more like a Spheriwm in these char- acteristics. It is quite abundant at the locality, but, as it is only found in an indurated clay matrix, good specimens are with difficulty obtained, and from these the thin shell is very liable to break and scale oif, leav- ing only the internal cast remaining. ‘Among the specimens collected there are some of a more transversely oval form and somewhat larger size than those I have regarded as the types of the species here described. These may belong to a distinct species, but they agree so nearly in all other known characters that I am at present inclined to regard them as merely a variety of the same. Locality and position. —Carleton’s coal mine, Coalville, Utah.” This species is one of an interesting estuary fauna ’ which was (is- covered by Mr. Meek in connection with a portion of the coal-bearing strata in the Cretaceous series at Coalville, Utah. The figures on plate 12 have been drawn from his types, which are among the only examples that have ever been collected. One of the species of this peculiar estuary fauna, namely, Physa carle- toni, was illustrated on plate 7, fig. 12, of Contributions to Invertebrate Paleontology No. 1, in the Annual Report of the Survey for 1877, and all the remaining species of that estuary fauna which have yet been deseribed are illustr ated upon plate 12 of this article. They embrace the following WHITE.] CRETACEOUS FOSSILS. 21 species: Anomia propatoris, Corbicula carletoni, Melampus? antiquus, Neritina bannisteri, Neritina (Velatella) bellatula, N. (V.) carditoides, Turritella spironema, Hulimella? inconspicua, H.? chrysallis, and Val- vata nana. The fauna also contains another Turritella, a Unio, and two or three other undetermined species. For Mr. Meek’s remarks upon this fauna see the Annual Report of this Survey for 1872, pp. 442-445. Peculiar interest attaches to this estuary fauna in different ways, but especially. because some of its species indicate the existence of types at that early period which are found to characterize the fossil molluscan faunze of later epochs as represented by North American strata; and of some that are also common among living North American forms. Espe- cial reference is had in this remark to the fresh-water and land mollusca. The strata containing the fossil fauna in question were evidently deposi- ted in the estuary of a stream, which, during at least a portion of the Cretaceous period, flowed into the sea from the narrow continental region of Mesozoic time, the eastern shore of which was evidently near that local- ity. There were doubtless other similar estuaries along that and other shores of the Cretaceous seas, but little is yet actually known of them. Unfortunately, also, the excavations which exposed the strata bearing the fauna in question, at Coalville, have been discontinued and covered. with débris, and none of its species have yet been found elsewhere. Our present knowledge of this deposit is therefore confined to that one limited locality. Genus PHARELLA Gray. PHARELLA? PEALEI Meek. ‘Plate 11, figs. 6 a and 6 b. Pharella? pealei Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, p. 496. No other than the type specimens of this species have ever been dis- covered; the best one of which, although only a cast, is figured on plate 11. The following is Mr. Meek’s description of it: “Shell elongate or subrhombic, the length being about twice and a half the height, rather compressed; anterior margin slightly sinuous just in advance of the beaks above, and somewhat narrowly rounded below this faint sinuosity ; posterior margin truncated, with a convex outline, very obliquely downward and backward from the posterior extremity of the hinge to the prominent and very narrowly-rounded or angular posterior basal extremity; hinge-line proper, apparently comparatively short, and not forming any angularity of outline at its connection with the sloping posterior dorsal margin; beaks rising a little above the hinge margin, but rather depressed and placed about one-fifth the entire length of the valves from the anterior margin; basal margin long, slightly sinuous along most of its length; posterior dorsal slopes rather prominently rounded from the beaks obliquely to the posterior basal extremity. Surface only showing obscure lines of growth. “Length, 1.20 inches; height, 0.48 inch; convexity, 0.28 inch. * Knowing nothing of the hinge of this shell I only referit provisionally to Pharella. it doesnot seem to have had the extremities gaping as in that genus, but the specimen has evidently been accidentally compressed, and this may have given the valves the appearance of being closed. In gen- eral appearance it resembles Solen guerangeri @Orbigny, which seems to belong to the genus Pharella. Our shell, however, evidently differs from dOrbigny’s specifically, at least, in not having the posterior margins of ie GEOLOGICAL SURVEY OF THE TERRITORIES. its valves near so abruptly truncated, but rounding and sloping forward gradually into the dorsal outline abov®. Possibly, I should call it Afod- tola pealet. “ Locality and position.—Missouri River, below Gallatin City, Mont. Cretaceous.” Genus TAPES Miuhlfeldt. TAPES HILGARDI Shumard. Plates 16, figs. 3 a, b, and ¢. Tapes hilgardi Shumard, 1860, Trans. St. Louis Acad. Sci., Vol I, p. 601. The following is Dr. Shumard’s description of this species (loc. cit.). ‘‘ Shell ovate, transversely elongate, valves compressed, convex; ex- tremities rounded, the anal end narrower than the buccal, and in adult Specimens approaching to subtruncate; cardinal border long, curving gently from the beaks posteriorly; basal margin very gently convex; beaks situated about one-third the length of the shell from the anterior margin, rather short, nearly in contact; ligament area depressed, narrow- lanceolate ; pallial sinus lingueeform, extending above the middle of the height of the shell. The surface markings are not well preserved in any of the specimens before me. They show merely fine concentric lines of growth near uae basal margin. “Length, 2 inches; width, 1.27; thickness, 0.66. Locality y. ” Blais of Red River, Lamar and Fannin counties (Texas), occurring in septaria of the marly clay, near the base of the Lower Cre- taceous.” In the collections of the National Museum are some examples which I reier to this species, one of which is represented by fig. 3 6 and another by fig. 3 c, plate 16. These examples were sent by Mr. D. H. Walker, from Bell County, Texas, with other Cretaceous species. Fig. 3 a of the same plate is from a photograph of Dr. Shumard’s original drawing which he had gven to the late Mr. Meek before his death. This species perhaps belongs to the genus Baroda Stoliczska, but as nothing is yet known of its hinge ¢ or interior markings I prefer to leave it where ‘Shumard placed it. Genus PACHYMYA Sowerby. PACHYMYA? COMPACTA White. Plate 17, figs. 4a and 6. Pachymya? compacta White, Jan., 1880, Proc. U. 8. National Museum, vol. ii, p. 297. Shell small, narrower posteriorly than anteriorly, slightly gaping be- hind; beaks depressed, approximate, incurved, directed forward, their position being very near the front; basal margin broadly convex; pos- terior margin narrowly rounded ; postero-dorsal margin forming an oblique downward and backward "truncation of that part of the shell; cardinal margin nearly straight, subparallel with the basal margin, much shorter than the full len ‘eth of the shell; ligament short, its area depressed and sharply defined; front very short, depressed beneath the beaks and narrowly rounded below ; umbonal ridges prominent, angu- lar or subangular; the space above and behind them moderately broad and flattened ; the remainder of the valve somewhat regularly convex. Hinge and interior markings unknown. Surface marked by the ordi- nary concentric lines of growth. WHITE.] CRETACEOUS FOSSILS. 23 Length, 29 millimeters; height, 18 millimeters; thicaness, both valves together, 14 millimeters. This species is evidently congeneric with the shell which, in the An. Rep. U.S. Geol. Sur. Terr. for 1877, p. 298, I described as Pachymya herseyi and also with the Cypricardia texana cf Roemer; but knowing nothing of the hinge of either of these forms I am not satisfied that they are properly referable to Pachymya. They are, however, here referred to that genus because of the agreement of their external characteristics with those of Pachymya. Position and locality.x—Cretaceous strata, Bell County, Texas, where it was collected by Mr. D. H. Walker. Genus THRACIA Leach. THRACIA MY A4FORMIS White. Plate 17, figs. 2a and bd. Thracia myeformis White, Jan., 1880, Proc. U. 8. National Museum, ‘vol. ii, p. 297. Shell transversely subovate in marginal outline; valves nearly equal; anterior end regularly rounded; wider and thicker anteriorly than pos- teriorly; posterior portion narrowed vertically and somewhat com- pressed laterally, but gaping at the extremity; basal border broadly convex; posterior border abruptly rounded; cardinal margin slightly convex; but the prominent umbones give the shell a concave appear- ance behind the beaks; a distinct linear depression is seen in the nat- ural cast, on each side of the ligament; beaks prominent, incurved, and directed a little forward; muscular impressions not distinctly shown in our examples, which are natural casts in chalky limestone, but the pal- lial sinus appears to have been large and subangular at its anterior end. Surface marked by the ordinary lines of growth, and also by more or less distinct irregular concentric wrinkles. Length, 57 millimeters; height, from base to umbo, 37 millimeters ; thickness, both valves together, 24 millimeters. This shell in general aspect, approaches T. proutt Meek & Hayden, from the Upper Fox Hills Group of the Upper Missouri River region ; but it differs in being proportionally narrower and more produced be- hind the beaks than that species, and in the greater prominence of the umbones. Position and locality.—Cretaceous strata of Bell County, Texas, where it was collected by Mr. D. H. Walker. GASTEROPODA. Genus MELAMPUS Montfort. MELAMPUS? ANTIQUUS Meek. » Plate 12, figs. 11 a b, c, and d. Melampus antiquus Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, p. 507. The following is Mr. Meek’s description of this species, together with his remarks upon the same: “Shell subovate, thin; spire moderately prominent, conical, and ab- ruptly pointed; volutions about eight; those of the spire very short 24 GEOLOGICAL, SURVEY OF THE TERRITORIES. and nearly flat; last one large, widest above and tapering below; su- ture shallow, with a slightly impressed line a little below it, around the upper margin of each volution; aperture narrow; columella and inner lip provided with four very prominent laminze or folds, with sometimes one or two smaller ones above these, near the top of the aperture; outer lip thin, and strengthened by a few transverse ridges within. Surface showing only fine obscure lines of growth and presenting a somewhat polished appearance. ‘“¢ Height of a small specimen 0.43 inch; breadth, about 0.27 inch. ‘I have only seen very imperfect specimens of this shell, but, taken together, they give a correct idea of nearly all of its characters. Some of them are three or four times the linear dimensions of that from which the above measurements were taken. ‘Among the specimens from the same locality and bed there are some very large broken examples, too imperfect for detailed description, that seem to belong to a more elongated species, with a more produced spire than that described above. This form, however, as far as its char- acters can be made out, appears to agree with the foregoing in nearly all other respects. If distinct, it may be called M. elongatus. “Locality and position. —Carleton’s coal: -mine, near Coalville, Utah. Cre- taceous.” After a full examination of all the specimens collected by Mr. Meek, ik am inclined to believe them to represent only one species, ‘and that the differences which exist are due only to interspecific variation. Figures 11a and 11), on plate 12, are drawn from the most perfect example dis- covered, although it is not more than one-third the size of some individ- uals which are represented in the collection by badly broken specimens. The four folds upon the inner lip, mentioned by Mr. Meek, vary in size and character. The two middle ones are stronger and more promi- nent than the other two. The anterior one is narrow and ridge-like, and is not so distinctly seen from without as the others are, and it ap- pears to be absent in the earlier stages of growth of the shell. The third one from the anterior end of the aperture, including the less conspicuous one just mentioned, is more transverse in its position than the others, and it is also hollowed upon its anterior side and a little flattened upon _ its ouver side in shells of fully adult growth. They all rest upon a layer of callus, which forms the inner lip, and constitute an unusually con- spicuous armature of the aperture. Figure 11d, plate 12, shows this ar- mature of a much broken, but very large example, natural size. Upon carefully cutting the indurated clay matrix from around the spire of several of the specimens of the collection, I find the first volu- tion of the minute apex to be reversed; or rather its axis is so turned as to have a different direction from that: of the axis of the body of the shell. Usually the two axes are nearly at right angles. The reversed portion is very minute, and may easily escape detection, even under an ordinary lens. Figure lle, plate 12, represents an enlarged view of the apex. This isan important feature, and suggests possible relationship of this shell to the Pyramidellide, with some members of which family it is faunally associated ; but its form, as well as most of its other character- istics, are much more like those of the Auriculide. Instead, however, of regarding it as a true Melampus, I am more disposed to regard it as congeneric with Rhytophorus Meek, the type-species of which is found in the Bear River Laramie strata. The longitudinal varices, occupy- ing the space immediately in advance of the narrow groove near the distal border of the volutions of the type of that genus, were regarded as of generic. importance by Mr. Meek, and suggested the name which WHITE.] CRETACEOUS FOSSILS. 25 he gave to the genus. These varices are not present on the shell here discussed; but to my mind the narrow groove situated near the distal border of the volutions in both shells is of greater generic value than the varices. Of equal or greater generic value also is the reversed apex of our shell, which is evidently a constant characteristic; but it is not yet known whether the apex of the type of Rhytophorus is also reversed. Until this question can be decided I prefer to leave this species where Mr. Meek originally placed it, in the genus Melampus, although it is quite certain that it does not strictly belong there, rather than to formally transfer it to Rhytophorus, or to propose a new generic name. MELAMPUS ? ——? Plate 12, fig. 6a. M-lampus ——? Meek, 1873, An. Rep. U: 8. Geol. Sur. Terr. for 1872, p. 439. Mr. Meek obtained from the marine strata at Coalville a single exam- ple of a shell, which is evidently congeneric with the Melampus antiquus, from the estuary beds there, aud which has just been described. It is too imperfect to base a specific description upon; but it is probably dis- tinct from the last-deseribed species. Allits associates are marine forms, and if it is a littoral pulmonate Gasteropod, as it is supposed to be, it was probably drifted to its marine entombment from an adjacent shore, just as the Physa probably was, which was found in the same or associated strata, and which is figured on plate 7, fig. 13, of Contributions to Inver- tebrate Paleontology No. 1,in the annual report of this survey for 1877. The character of the specimen here referred to Melampus is well shown by fig. 6 a, plate 12, but it is thought best to wait for better examples before giving it a specific name. Genus NERITINA Lamarck. NERITINA BANNISTERI Meek. Plate 12, figs. 10 a, b, and e. Neritina (Neritella) bannisteri, Meck, 1873, An. Rep. U. S. Geol. Sur. Terr. for 1872, p. 499. This species is one of the estuary Cretaceous fauna before referred to, which was discovered by Mr. Meek, at Coalville, Utah. The figures of it on plate 12 have been drawn from one of Mr. Meek’s types, and the follow- ing is his description of the species, together with his remarks upon the same : “Shell, subglobose; spire much depressed, or with its apex scarcely rising above the body-whorl; volutions three or four, rapidly increas- ing in size, so that the last one comprises neariy the entire shell, more or less flattened, and sometimes provided with an obscure linear revolv- ing furrow above; aperture large, subovate, approaching semicircular, being a little straighter on the inner side; outer lip beveled to a thin edge; inner lip of moderate breadth, slightly concave, and flattened, with asteep inward slope, entirely smooth. Surface polished, and marked by crowded zigzag vertical bands of brown and light-yellowish colors ; lines of growth moderately distinct. “ Height of a nearly medium-sized specimen 0.40 inch; breadth, 0.43 inch. Some examples are as much as twice these dimensions. 26 GEOLOGICAL SURVEY OF THE TERRITORIES. “ Although the specimens show the pattern or style of the original coloration of this shell quite distinctly, the colors themselves may, of course, have been different in the living shell. Usually the zigzag mark- ings are quite distinct on the specimen as found, but on some examples the bands are blended, and become fainter, so that the surface merely presents a light brownish tinge. Itis always polished, however, on all the specimens seen. “This species seems to be more nearly allied to WV. nebrascensis M. & H., from the Jurassic beds, near the head of Wind River, than .to any other form with which Iam acquainted. It may be readily distin- guished, however, by its more depressed spire, and the slight flattening of its volutions above, as well as by its more flattened and more concave inner lip. It likewise attained a larger size than any of the specimens of that species I have seen. It is one of the most abundant shells ob- served at the locality, and is usually found in a better state of preser- vation than any of its associates. “ Position and locality.—Carleton’s coal mine, Coalville, Utah.” This species is closely related to V. incompta White, from marine Cre- taceous strata at Hilliard Station, about 40 miles northward from Coal- ville, and which is figured on plate 7 of Contributions to Invertebrate Paleontology No. 1, Annual Report of this Survey for 1877; but its dif- ferences are pointed out in connection with the accompanying descrip- tion of that species. NERITINA PISIFORMIS Meek. Plate 12, figs. 9 a, b, and e. Neritina pisiformis Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, p. 500. This shell is found associated with N. piswm Meek, which is figured on plate 7, accompanying Contributions to Invertebr ate Paleontology No. 1, in the Annual Report of this Survey for 1877, and also with many other "forms in the marine Cretaceous series of strata exposed at Coal- ville, Utah. The figures on: plate 12 have been drawn from one of Mr. Meek’s types, enlarged two diameters, while those of NV. piswm, just re- ferred to, are ‘ot natural size. In size and general aspect the two species are closely alike, as may be seen by comparing the figures of both, and as has also been pointed out by Mr. Meek. ‘The following is his descrip- tion of this species: “Shell smail, subglobose, or obliquely rhombic, the height being slightly less than the oblique breadth; spire rather prominent for a species of this genus ; volutions three to three and a half, convex; aper- ture subovate, considerably contracted by the flattened, moderately wide inner lip, which is nearly straight on its inner mar ein, and pro- vided there with four small denticles, the upper one of which is largest; surface smooth. ‘‘ Height, 0.30 inch ; greatest oblique breadth, 0.32 inch. “This little shell agrees so nearly in size and form with the described species (N. pisum) that they may be readily confounded, as they are found with the aperture filled with rock. ““A fortunate fracture of one of the specimens exposed the inner edge of its flattened columella, however, and thus enabled me to see that it is denticulated, and in this respect differs from Neritina pisum, which seems to be entirely without teeth. Further comparisons also show the two shells to differ in form, that under consideration having a more promi- - nent spire and a more ’elobose outline, being less oblique. WHITE. ] CRETACEUUS FOSSILS. 2% “In size and general appearance it also closely resembles small examples of Neritina compacta Forbes, from the Cretaceous rocks of India, but it is less oblique, or more globose in form, and has four den- ticles instead of only three on its columella. It is possible that I should call it Nerita pisiformis, as the denticulations of its columella are rather strongly developed for a Neritina, in which genus the columella is usually smooth, or only finely crenate. Its general aspect, however, is more like species of the latter group. “ Locality and position.—Coalville, Utah, from the Cretaceous beds below the lower heavy bed of coal mined there. Subgenus VELATELLA Meek. No diagnosis of this type having yet been published, although Mr. Meek proposed a name for it on p. 499 An. Rep. U. S. Geol. Surv. Terr. for 1872, I propose the following diagnosis, which is drawn from all the yet known forms belonging to it, namely: Neritina ( Velatella) bellatula and N.(V.) carditoides Meek, from the estuary Cretaceous strata at Coalville, Utah; WN. (V.) patelliformis Meek, and var. weberensis White, from the marine Cretaceous strata at the same place; and NV. (V.) baptista White from the Laramie Group at Black Buttes Station, Wyoming. Shell resembling both Dostia and Velates, suboval in outline, depressed convex above, flattened beneath; beak minute, incurved, turned a little to one side, and depressed nearly or quite to the posterior margin ; inner lip large, flattened or slightly convex, its border smooth or crenulate ; outer lip usually a little thickened and sometimes crenulate within, and more or less contmuous with the inner lip; aperture comparatively small; surface smooth or radiately ribbed; usually polished. It differs from Dostia in its more nearly perfect bilateral. symmetry and its minute apex; and from Velates in having its apex always depressed to the pos- - terior border. ey 3 i NERITINA (VELATELEA) BELLATULA Meek. Plate 12, figs. 8a and b. Neritina (Dostia?) bellatula Meek, 1873, An. Rep. U. 8S. Geol. Sur. Terr. for 1872, p. 497. The type which in this article is represented by the two following de- scribed forms, while it is closely related to Dostia Gray, and Velates Montfort, is doubtless worthy of the subgeneric distinction suggested for it by Mr. Meek in connection with his specific description of them in the Annual Report of this Survey for 1872, pp. 197 and 198. The pub- lication of a diagnosis of the type being necessary for its proper recog- nition, and Mr. Meek having failed to publish one, I have drawn the foregoing one from the characteristics presented by all the known forms which are referable to this type. The two forms described in this article were discovered by Mr. Meek associated together, and torming a part of the estuary Cretaceous fauna at Coalville, Utah, which has already been mentioned. Another species of the same type N. (V.) patelliformis is found in the marine Cretaceous strata of the same neighborhood, and the only other known species be- longing to it was discovered by the writer in the upper strata of the Laramie Group at Black Buttes Station, Wyoming. The latter form is figured, on plate 29; and XN. (V.) patelliformis, together with a variety of the same, is figured on plate 7, accompanying Contributions to Inverte- 28 GEOLOGICAL SURVEY OF THE TERRITORIES. brate Paleontology No. 1, in the Annual Report of this Survey for 1877. The following is Mr. Meek’s description of this species, together with his remarks upon the same: ‘Shell small, depressed-ovate, or broad slipper-shaped; apex very small, and depressed to the posterior margin, where it forms one or two minute, slightly oblique, compact turns, that do not project beyond the margin, but are sometimes even slightly overlapped by it; inner lip very _ broad, or shelf-like, and occupying more than half the under side, con- vex, and more or less thickened, with the inner margin concave in out- line at the middle, and provided with a slight projection on each side, but not properly crenate or dentate; outer lip rather thick, obtuse, nearly or quite smooth, and continuous around the margins with the inner one; aperture small and transversely semicircular. Surface polished, and or- namented by from fifteen to twenty light yellowish or cream-colored simple radiating coste, separated by shallow, light brownish furrows of about the same breadth ;* lines of growth moderately distinct. ‘‘Length, 0. 31 inch; breadth, 0.25 inch; convexity, 0.12 inch. “JT am in some doubt in regard to the proper disposition to make of this little shell. In most of its characters it seems to conform pretty nearly with Dostia Gray, generally regarded as a subgenus ‘under YVeri- tina Lamarck (=Neritella Humphrey). It has a much smaller and less prominent spire, however, and a more convex and broader inner lip than the type of that group, and also wants the crenulations of the inner lip seen in the same. Inits limpet-like form, tumid, greatly developed inner lip, and minutely coiled apex, it approaches Velates Montfort, and I am not quite sure that it would not be nearer right to eall it Velates bella- tula. Still it differs from the typical form of that genus in having its apex depressed to the posterior margin, instead of being elevated and nearly central, while the margin of its inner lip wants the distinct den- ticulations seen in that of that shell. “Of course if Humphrey’s catalogue genera are to be adopted on ac- count of priority of date over those.of Lamarck and others that were accompanied by diagnoses, the name of this shell, supposing the view here adopted in regard to its affinities to. be correct, would become Nerv- tella (Dostiay bellatula. Ee “ Locality and position.—Carleton’s coal mine, Coalville, Utah.” NERITINA (VELATELLA) CARDITOIDES Meek. Plate 12, fig.:7 a. gate ey carditoides Meek, 1873, An. Rep. U. S. Geol. Sur. Terr. for 1872, p. This form certainly belongs to the same type as the preceding, and there appears to be some ground for suspecting them to belong to one and the same species. All the specimens in the collection of both this and the other form are more or less imperfect, however, and I therefore prefer to treat them as separate species in this article, as Mr. Meek has dune. The following is his diagnosis of this form: “Shell attaining a moderately large size, broad, oval and depressed in form, apex posterior and nearly or quite depressed to the margin, ap- parently subspiral; inner lip very broad or forming more than half the under side, rather thick, smooth, and nearly flat, or somewhat convex, with its straight inner margin sharp and without teeth or erenulations; “Of course the colors mentioned are not known to present the same tints in the fossil shells that ornamented them when the animal was alive.” WHITE. | CRETACEOUS FOSSILS. 29 outer lip thick, very obscurely crenate within, and apparently continu- ous with the margins of the inner one around behind;. aperture trans- versely semicircular, and less than half the size of the under side of the shell. Surface ornamented by about fifteen simple, narrow, sharp, and subcrenate radiating cost, separated by wider, rounded intermediate furrows; lines of growth distinct. ‘Length about 0.87 inch; breadth, 0.70 inch; convexity, 0.35 inch. “This is another curious form allied to the little species I have described under the name WN. bellatula. When viewed from the dorsal side, as seen lying with the aperture downward, its form and strong radiating cost give it much the appearance of the left valve of a Cardita or Car- dium. The only specimen of it in the collection has its apex and pos- terior and lateral margins broken away, and its broad, smooth, shelf-like inner lips broken by pressure inward. Still, however, it gives a tolera- bly correct idea of the characters of the shell. In several respects it agrees with Velates, and possibly might without impropriety be called Velates carditoides. . I suspect, however, that when better specimens can be examined it will be found tpyical of an undescribed section, including also the little species N. bellatula. Ifso, I would propose for the group the name Velatella. I know of no nearly allied type. “ Locality and position.—Carleton’s coal-mine, Coalville, Utah. Cre- taceous.” Genus EUSPIRA Agassiz. KUSPIRA UTAHENSIS White. This species was erroneously mentioned and described in the An. Rep. U.S. Geol. Sur. Terr. for 1877, under the name of H. coalvillensis. (See pages 237, 253, and 310; and also explanation of plate 4 of that volume. . Genus TESSAROLAX Gabb. TESSAROLAX HITZII (sp. nov.) Plate 15, fig. 2a. Shell rather small; length of the spire about one-half that of the whole body of the shell exclusive of the canals; its apex a little blunted ; volutions about five, that of the body bearing two revolving angles or narrow ridges which apparently end respectively upon the two slender spines of the outer lip; the whole spire covered with:a layer of callus which obscures the sutures, and also the original surface of the volu- tions upon which there are apparently some revolving lines; outer lip bearing two long slender spines projecting from its border, each being grooved upon its under surface; the anterior labial spine directed out- ward and forward, and having near its middle a moderate enlargement, where it is also bent a little downward; the posterior labial spine grad- ually and uniformly tapering from base to point, directed outward and slightly curved backward; anterior canal long slender and spine like, flexed a little downward and to the left, its grooves being very narrow and linear; posterior canal also. slender, its grooves being narrew and linear like that of the canal and the labial spines, extending from the aperture close alongside of the spire and projecting as a slender spine much beyond its apex, from which it gently curves to the right; the 30 GEOLOGICAL SURVEY OF THE TERRITORIES. -eallus which covers the shell apparently little if any thickened upon the inner lip. Length, from the base of the anterior canal to the apex of the spire, 19 millimeters ; breadth of body-volution, exclusive of the aperture and — euter lip, 9 millimeters; breadth, including the aperture and outer lip, but excluding the labial spines, 14 millimeters. The apices “of both the anterior and posterior canals, and also of the posterior labial spine are broken off in the type specimen, but the ante- rior spine is entire, and the others are evidently nearly so, the anterior spine being 19 millimeters in length. The portion remaining of the pos- terior canal projects 5 millimeters beyond the apex of the spire, and that of the anterior canal projects 7 millimeters beyond the anterior border of the aperture. The anterior and posterior canal-spines and the posterior labial spine are each about 13 millimeters in diameter, the anterior labial spine being about double that width at its mid- length where it is broadest. This shell appears to have borne no varices or tubercles upon the eal- lus-covering of the body-volution such as characterizes the type species ot Tessarolax. Mr. Gabb appears to have regarded that feature as of generic importance, but I am disposed to consider it as only a specific character. Perhaps no family of shells with which the paleontologist has to deal is more in need of careful revision than the Aporrhaide. Of the various genera and subgenera which have been proposed by different authors, some doubtless ought to be rejected, but that all should be discarded and the species all referred to Aporrhais, as is the custom of some an- thors, appears to be unadvisable. ‘The covering of the whole shell with callus, as in Lispodesthes and Tessarolaw seems necessarily to have been correlated with characters in the animal which would separate it gener- ally from such forms as those which American authors generally refer to Anchura. The character of the anterior and posterior canals and labial spines of such forms as Tessarolax distorta and T. hitzvi, seem also sufficient to separate them generically from Anchura, Lispodesthes, and other proposed genera of the Aporrhaide. Tessarolax and Lispodesthes are both entirely callus-covered forms, and both are yet known only in Cretaceous strata; to which also other forms of the Aporrhaidz seem to be restricted. Aside from zobdlogical con- siderations, perhaps the strongest conventional reason for retaining the generic¢ distinctions which have been recognized in at least a part of the Cretaceous forms of this family lies in the fact that they seem to be characteristic of the Cretaceous period. Position and locality—The species here described was obtained, ac- cording to the records of the United States National Museum, by Dr. hk. B. Hitz, from the Fort Pierre Cretaceous Group, at Fort Shaw, near Muscleshell River, Montana. The specific name is given in his honor. Genus LISPODESTHES White. LISPODESTHES? OBSCURATA (Sp. NOV.) Plate 11, figs. 7 a and b. Shell subfusiform; spire rather short, tapering with nearly straight sides to the apex; volutions six or seven, convex; last or body volution rather large, without a revolving angle; suture impressed ; outer lip or _ Wing comparatively small, as indicated by all the known specimens, its ‘WHITE.] CRETACEOUS FOSSILS. 31 ‘outer border bearing a slender, tongue-like projection, which extends outward and forward from the anterior portion of the wing margin. Fhe posterior portion of the wing is not accurately known, as all the Specimens are more or less imperfect in that respect, but it seems not to have been prolonged backward in the form of a pointed projection, as it is in Anchura and the typical forms of Lispodesthes. That portion of the wing apparently formed a broad, short, blunt projection, which was broadly concave beneath, posteriorly ; but there is in our examples no appearance of a true posterior canal such as characterizes the typi- eal forms of Lispodesthes. Anterior canal comparatively broad and long; beak moderately broad, rounded at the anterior end, but with a Shorter curve at the left side than at the right. Shell (the callus being removed) thin and delicate, its whole surface marked by very fine lines of growth, and also by very fine crowded raised revolving “lines, which are a little more conspicuous than the former, but they all need a lens to render them distinctly visible. There is also a narrow, square shoul- dering of the distal border of the volutions of the spire at the suture. Length, irom the apex to the end of the anterior canal, 37 millimeters ; breadth, across the body volution and wing, 18 milimeters. Hig. 7a, plate 11, represents a specimen with the entire callus removed, but with the shell proper remaining. Fig. 7 b, of the same plate rep- resents an imperfect example with the spire, and a portion of the body volution still covered with callus. The indications furnished by the other specimens of the collection, all of which are imperfect, are that the whole shell, when adult, was covered with callus, as in Dispodesthes White and Calyptraphorus Conrad. This shell certainly does not be- long to the latter genus, and it also presents some important differences ‘from the typical forms of Lispodesthes. For example, it has evidently ‘no posterior canal hollowed out of the callus and extending along the spire nearly or quite to the apex, as in the latter genus. This seems to be an important difference. A lesser one is the apparent absence of a falciform projection of the posterior portion of the wing. It agrees with LInispodesthes in general form, in the callus-covering of the whole shell, and the anterior tongue-like projection from the wing. I therefore refer it provisionally to that genus, notwithstanding the differences before mentioned, because no other one of the numerous established genera of ‘the Aporrhaide will receive it; and because the examples yet known will not warrant a full generic diagnosis. For some general remarks on re- lated genera, see paragraph following description of the preceding species. Position and locality—The only specimens yet known, which are cer- tainly referable to this species, were collected by Dr. Hayden at ‘‘Dod- son’s Ranch, near Pueblo, Colorado”; apparently from strata of the Fox Hills Group. IR ek aL Neary a4 i eubettting tip i Pear RPA wR eae MMe & ands Suisse } atone fh ids ae agiebiar/3 By LEK Pi alert Ba eat Mr ie su MATA: ven: 4. uy? Ak ve Fie. 1. Fig. 2. Fig. 3. Fig. 4. On Fic. Fic. 6. Fia. x Fic. 8. Fig. 9. Fic. 10. Fic, 11. Fic. 12. Fig. 13. Fia. 14. Fa. 15. Fia. 16. Fig. 17. PLATE 12. FASCIOLARIA (PIESTOCHEILUS) ALLENI ..-....-.--..----- Gods baao SoS. a. Side view; natural size. FUSUS UTAHENSIS ..--.----..-- ----0- -- 0-0 --- enn == o> === aye a. Side view of a natural cast in sandstone; natural size. MURRIETA YW SPEER ONEMAss sce) )eae aie scene aia enicteiek cialsinisetsiete pot a. Side view; enlarged to two diameters. EULIMELLA? CHRYSALLIS .....-.-..---- Byres EP Seales oiler a. Side view; enlarged to four diameters. EULIMELLA? INCONSPICUA ..--- Se Seen BE ane PADMA Ean acca oon oSdc a. Side view; enlarged to four diameters. MELAMPUS? ———? .......----. .----- --000- --- eee Fiat eee PAI NE a. Side view of a cast in sandstone; natural size. . NERITINA (VELATELLA) CARDITOIDES. ...-.. --.------- Sapage saga oac0 a. Dorsal view ; natural size. NERITINA (VELATELLA) BELLATULA.........---..-- aya aed are ee wee a. Side view ; enlarged. b. Dorsal view of another example; enlarged. INTRON TINO ooo) 66 boo cben GobSos Fasc somoce aS BGbooE BOoboE 4 a. Side view; enlarged to two diameters. b. Apical view of the same. e. An example with a part of the outer volution broken away, show- ing the lip and its subdentate inner border. INITDP ERM ENOA, TEVAONESTISIMDIRN S555 Shoah onudao Sogo boobus osoosEbadsedes ees a. Side view; natural size; showing pattern of color-marks. b. Apical view of another example. c. Apertural view of the same, showing the plain lip. MELAMP US? “AINTIQ WU Secs cel cia tyes eis eee ea RO PSE eg pe a. Side view of a young example; enlarged to four diameters. b. Apertural view of the same, showing armature of inner lip in the young state. c. Summit of the spire; greatly enlarged; showing the reversed apex. d. Fragment of a large example; natural size; showing full armature of inner lip of adult shell. OPHTODERMAV DBRID GURENSISiee eee ee esac ene eee ee eee eee eee eee a. View of Mr. Meek’s type specimen; enlarged to 14 diameters. BEAU MON TIA?) SOLU LA RTA ee eed eel cui is alaratcta le eter siege es a. View of the cleft side of a fragment of a corallum; natural size. b. Summit view of a group of corallites. c. Side view of a section cf a group of corallites; enlarged. CHATETES?? DIMISSUS......----.-- sales AU Lal Ce LO Re eS a. Branch of a corallum; natural size; showing the diverging coral- lites at broken ends of the branches. ANOMIA PROPATORIS......-. .---------- AN as ols ia RA ACIS te Ra a, Exterior view of upper valve; natural size. b. Lateral view of the same. CYR ENAY CARI DONT oooh ese OU Met RIL AT aT Sed ae PoE eta A UT Apa a. Left side view; natural size. b. Dorsal view of the same. WOAAONION, RAISIN Co Ges hb oce coos Pea SPCR oT HREI AE ee NO ARIEL Cane Mae EA PRL EE A a. Lateral view ; enlarged to five diameters. b. Apical view of the same. 27 26 a) i4 33 CRETACEOUS. pe p23 Sessa Gz, 2 on, Lith S hos, 5inclair:& Tv T D Owen Del &F s WH.Holme iy au 4 at CN eT aM NA i PLATE 13. FEU ait Mone) GVaIBAC WIRING EDITaIaD ce one DIAC Noa a ee att a. Interior view of the lower valve in its natural posture when ad- herent to a foreign body, the front side being much higher than the other; natural size. b. View of the front side of the same, the right-hand border of the figure being that of the adherent surface of the valve. ce. Upper valve; exterior surface. d. Interior surface of the same. CRETACEOUS. U.S.GEOLOGICAL SURVEY PL Sinclair il J.6.M° Connell del. a Ce mae St Me “ beth pale ie a eiRh RESIN | hie Ale PLATE 14. Page. JONG, Il, ORR BC/ANOMGDl 455 oooKnS Sobo cogcds soba cadbcasonosas S65 COHOED Rodoos 11 a. Outer view of the lower valve of a large emrumplo: natural size. bd. Upper view of the same example. For interior view of upper valve see plate 17. Fic. 2. EXOGYRA FORNICULATA ..--.. ----- eee ie Sere cee ere ey See anette rae 13 a. Outside view of lower valve; natural size. b. Interior view of the same. 16 TONG. St. Cane b oN I RODOXOIOARUNG Fo San oS ccuo coco 6 p6O06d Gane nedG bokcoG Seod ocab0C a. Left side view of a natural cast of the interior; natural size. b. Dorsal view of the same. ee CRETACEOUS. US. GEOLOGICAL SURVEY = J.C.M* Connell del. Thos. Sinclair*& Son, Lith aa Bt PLATE 15. BG Wl eRLONOCY. CLUS) WiiOMUNGENSIS 225) ealt.ss) se orauin ae ley eees weet oeieies a, Fragment showing side view of portions of two volutions. o. Peripheral view of another example, the carina of which has been mostly broken away. a c. Side view of another example, showing the character of the earlier volutions. d. Peripheral view of the same. e. Septal suture; from fig. 1 b. All of natural size. EGY: TIMES SIAR.© iA EDIT ja) UR iy Sil ASA ANIA Cail ON A a Ca CO ag a. Figure of a gutta-percha cast of the type specimen, showing the spire and the greater part of the under side of the shell, with its spines; natural size. 29 CRETACEOUS. U.S.GEOLOGICAL SURVEY ; BANE J.C. Me Conirell del. Thos Sinclair& Son, Lith | PLATE 16. Page. em eres eee ee ee ee ee Pee een we ee ee ee te es pees cee eee Fic. 1. PARAMITHRAX WALKERI a. Claw of right anterior limb; outer view; natural size. 6. Transverse section of fixed finger. c. Transverse section of movable finger. For opposite side view of the same see plate 17. 15 Fic. 2. PTERIA (OXYTOMA) SALINENSIS a. Left side view of a natural cast of the interior; natural size. b. Dorsal view of the same. 22 eres See eee tee eee eH oe ee Be wo ee ee eee ee ee ee ee ee ee oe eae Pig. 3. TAPES HILGARDI a. Copy of Dr. Shumard’s original drawing. b. Dorsal view of a smaller example from Bell County, Texas. c. Left side view of another example from the same locality. All of natural size. CRETACEOUS. US.GEOLOGICAL SURVEY : ; REATE a6 Thos: Sinclair’& Son, Lith: vis ; ‘ ri OR ee ae ig im em ole et PLATE 17. PIG: wy PARAMITHB AX WADKERT (ne os cyaccicinsielaqs es ala tvotes avieiersie welave rete ueiaeiais eens 37¢ a. Claw of right anterior limb; inner view; natural size. For opposite view of the same see plate 16. IDG, Py ANETRAGION INOCADINODEMONS) GaGado coG0da Shas bo Ké Obed Cond 466 Bone Sasean oben s 23 a. Right side view of a natural cast in chalky limestone; natural size. b. Dorsal view of the same. TG ogee PE RTA) Ss DAB WELD ACBIS aneioreiclaisisiersaie re cele siete inintseietteisisieheiatiortteeisistainteratete 15 a. View of one adult, and several smaller lower valves, attached to a fragment of the shell of an Inoceramus. Fig. 4. PACHYMYA? COMPACTA ..... GIBB SU ES SHOH SoaoEH aU GOOGds Gadsog vabauaeace 22 a. Right side view; natural size. b. Dorsal view of the same. LBC Bp (OSIRIA. ICACISIN E6555 c00568 66000 695058 Ga05 obadodcod6 So eb6dde soboa0¢ 11 a. Interior view of upper valve; natural size. For other figures of this species see plate 14. *YAUT ‘MOS B.drepoutg “soul ‘EP 119U40D WOT Y PIStRIIM dw ASAYNS 1919010359 SN ‘SNOFOV.LEYO AV 4alW dd anes a wal Fic. FIG. Fic. Fig. Fia. Fig. Fie. FIG. FIG. PLATE 18. [Illustrating species published by Dr. B. F. Shumard.] Thy JAGACOIP ENDS) Rhy Wri KO2 bl So ooosaaKose.coKd cuba cdooad Kdso dances noenoo ces a a. Side view. 2. CIDARIS HEMIGRANOSUS ..--- pdoca osed coo BSBC nono EHeE cece dadaseod6 a. Fragment showing body-plates and part of an ambulacral area. b. Another fragment. 3. GERVILLIA GREGARIA.....-..-------- gHenbasacH sas Sas e/aror ate tuteriarerete ea ie a. Left valve. 4. CYTHEREA LAMARENSIS..-.-...-- SECO er BeOS AIS oc PHS A a. Left side view. b. Dorsal view of the same. 5 SN UCULA BELLASTRIATA A oe ae e Sale Me ta cls ei papa emer reer eee a. Right side view. b. Dorsal view of the same. ce. Dorsal] view of a natural cast of the interior of a large example. GEENU-C UGA HUANYaD BINT neater re a a tes 0 eee sinless Rise tee caer a. Right side view. b. Dorsal view of the same. 7. CARDIUM CHOCTAWENSE ..........-..--- at ocdg esos oceo ce oocesd bones a. Side view. b. Front view of the same. c. Coste and concentric lines enlarged. SSISCAPHITES VER MICUIEUS Wee e een oases en nee eras Sisal PSE ate ae Pos Nd a. Side view. 9. AMMONITES GRAYSONENSIS -....-- FEAL epee at ant uate mains aes tel AT i a. Side view. b. Peripheral view of the same. Fig. 10. ANCYLOCERAS ANNULATUM.........-.-----c- «< UG cam aeration Oy al aS a. Peripheral view of a fragment. b. Side view of the same. 38 39 39 39 KS) SHOU SRETAC a i i tapelict CONTRIBUTIONS TO INVERTEBRATE PALEONTOLOGY, NO. 3: Tria Ea eae MOLLUSCA FROM COLORADO, UTAH, AND By C. A. WHITE, M. D. The fossil mollusca herein described, and figured upon plate 13, have been collected at various times and by different persons connected with the two surveys which have heretofore been under the direction respect- ively of Dr. Hayden and Prof. Powell. Preliminary descriptions of all the species have before been published in different reports of those sur- veys, but none of them have before been figured. All the specimens figured on plate 13 are regarded as typical of the respective species, and the greater part of them are those from which the original descriptions were drawn. The type specimens—that is, those from which the origi- nal descriptions were drawn—have been used for illustration in all cases when they have been available; search for the types of a part of these species has, however, been hitherto unsuccessful, in consequence of their having been lost or mislaid. In these cases figures are given of speci- mens that have been carefully identified, and which have been collected from the same formations in which the original types were found, and at or near the original locality. All the species presented in this article are from the great fresh-water series of strata, which is usually, and doubtless correctly, referred to the Eocene Tertiary epoch, and which is divided into the Wahsatch, Green River, and Bridger Groups. There seems to be sufficient reasons of a physical character for dividing that great series of strata into the three subordinate groups just named, for purposes of stratigraphical study, but it is evident that a large proportion of the molluscan species which they contain are common to more than one, and in some eases at least, to all three, of the groups. The general characteristics of the inver- tebrate faunze of these groups is such also as to indicate their connection with, and proper reference to, a single epoch ; and such also as indicate not only a continuity of deposition over a very large area throughout the whole of the triple series, but also a continuity of existence of specific forms of molluscan life in the waters in which the whole of that con- tinuous deposition took place. CONCHIFERA. Genus UNIO Retzius. UNIO SHOSHONENSIS White. Plate 19, figs. 2 a and b. Unio shoshonensis White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 126. Shell subelliptical in marginal outline; valves moderately and some- what regularly convex; test not massive; dorsal margin broadly convex; front margin regularly rounded; basal margin broadly and regularly convex; posterior margin somewhat abruptly rounded, the postero-dor- Al 42 GEOLOGICAL SURVEY OF THE TERRITORIES. sal portion sometimes showing an oblique truncation or a sloping down- ward and backward of its border to a somewhat prominent posterior or postero-basal extremity ; beaks well defined but not prominent, situated about one-quarter of the full length of the shell from the front, or some- times less; umbonal slopes broadly convex. Surface marked by the ordinary concentric lines and imbrications of growth. Length of one of the largest examples in the collection, the one which is represented by fig. 2 a, plate 19, 65 millimeters; height of the same from base to dorsal margin, 43 millimeters; convexity of the single valve, 14 millimeters. Other examples have a greater, proportional length, as shown by fig. 2 b of the same plate. This species bears a closer resemblance to U. haydeni Meek, which has been reported from both the Green River and Bridger Groups, than to any other fossil form that has yet been published. It differs from that species in its larger size, its convex instead of Straight dorsal margin, its rather more prominent umbones, its some- what stronger hinge, and in its greater proportionate height from base to hinge margin. It belongs to that general group of the Uniones which have an oval marginal outline, the beaks submedially situated, and the surface plain; which group has several known representatives among the fossil Uniones of the western fresh-water tertiary deposits, and also a large number among living forms. In the latter respect it may be compared with U. fascinans and U. copei Lea, from the rivers of Virginia. It is not improbable that this species is really identical with U. telli- noides (= Mya tellinoides Hall, Frémont’s Expl. Oreg. and N. Cal., 1845). I have not had an opportunity, however, to examine Professor Halls type specimens, and, in view of the fact that several closely related species exist in the fresh-water deposits of the region from which Pro- fessor Hall’s types came, it is impracticable to determine from his figures and description alone to which species they were intended to apply. Fig. 2 a, plate 19, represents a typical example of U. shoshonensis from the Upper Green River Group of Southern Wyoming, and fig. 2 b, of the same plate, another more elongate example from the base of the Green River Group, or the top of the Wahsatch, in the valley of White River, Northwestern Colorado. Position and locality.—This species has a wide geographical distribution and a considerable vertical range. Its present known range is from the base of the Lower to the top of the Upper Green River Group, and it probably extends into the Wahsatch Group below and into the Bridger above. I have collected examples of it from the Green River Group in the valleys of Snake and White Rivers and Vermilion Creek, and from the slopes of Dry Mountains in Northwestern Colorado; also from the - Same group in the valley of Henry’s Fork, southward from Green River City, and near Alkali Stage Station, some twenty miles north of that place, in Southern Wyoming. UNIO WASHAKIENSIS Meek. Plate 19, figs. 3 a and b. Uirio washakiensis Meek, 1871, An. Rep. U. S. Geol. Sur. Terr. for 1870, p. 314. The following is Mr. Meek’s original description of this species (loc. cit. ): “Shell scarcely attaining a medium size, thin, depressed, rather com- pressed, longitudinally subovate ; anterior side short, rounded ; poste- rior side long, with a narrowly rounded or sometimes faintly subtrun- cated extremity, the most prominent point being below the middle, while above this there is usually an oblique slope from the posterior extremity wHITs.] TERTIARY FOSSILS. 43 of the hinge; basal margin forming a broad semi-elliptic or semi-ovate curve, in the latter case the most prominent part being a little in advance of the middle; dorsal or hinge margin straight from the beaks to the upper slope of the posterior margin; beaks depressed nearly to the dor- sal margin, rather regularly convex, but not ventricose, and placed about one-fourth the length of the valves from the anterior extremity ; umbonal slopes moderately and evenly convex. Surface smooth or only showing more or less distinct marks of growth, excepting near the im- mediate points of the beaks, where well-preserved specimens show traces of minute regular longitudinal wrinkles which terminate posteriorly at two faint, oblique, obsolescent linear ridges; hinge slender; cardinal teeth small, oblique, and apparently consisting of one in the right and two in the left valve; lateral teeth straight, rather long, two in the left and one or two in the right valve. “Length of a large specimen 2.37 inches; height, 1.26 inches; con- vexity, 0.72 inch. “This species is related to U. priscus M. and H., with which it agrees nearly in form and surface characters. It is constantly smaller, how- ever, and distinctly thinner, while its hinge is weaker and its cardinal teeth smaller and much more oblique. The wrinkles on its beaks, and the two oblique linear ridges on their posterior dorsal sides, are similar to those on U. priscus, excepting that they are less distinctly defined and occupy a much smaller space only near the points instead of the whole surface of the umbones, being, in fact, so obscure and so near the points of the beaks as to be readily overlooked, and entirely obsolete in most es. “ It will be distinguished from U. haydeni mainly by its more depressed and more elongate form ; its stratigraphical position is also, according to Dr. Hayden’s observations, one thousand to two thousand feet lower in the series than that of U. haydeni.” ‘ Mr. Meek does not expressly state from which of the three great fresh- water groups of strata his type specimens came, but, judging from what is known of the strata at the localities he mentions (Washakie and Henry’s Fork, Wyoming), they are all from the Green River Group. The vertical range of the species, however, is apparently from the base of the Green River Group to at least the lower part of the Bridger Group. The type specimens from which Mr. Meek drew his description seem to have been lost or mislaid, and I have, therefore, not been able to examine them. The one from which fig. 3 a, plate 19, is drawn was found among other fossils that had been studied by him, and was la- beled in his handwriting, “From Church Buttes, Wyoming.” Church Buttes being composed of the strata of the Bridger Group, as well as the character of the stone embedding the shells, indicates that they came from that group, probably near its base. The specimen repre- sented by fig. 2b, of the same plate, is from the base of the Green River Group, in White River Valley, Northwestern Colorado. The species is well characterized by Mr. Meek, and the specimens here figured, as well as the others associated with them, answer well to his description. UNIO MEEKIL White. Plate 19, fig. 1 a. Unio leanus Meek, 1871, An. Rep. U.S. Geol. Sur. Terr. for 1870, p. 318. Unio meckii White, 1877, Bull. U.S. Geol. Sur. Terr., vol. iii, p. 665. The original name of this species was changed by the writer, as above indicated, because it had been preoccupied by Gray many years ago. 44 GEOLOGICAL SURVEY OF THE TERRITORIES. It is not a very rare species, but no examples have ever been obtained which are in a better condition than those are from which Mr. Meek drew his description, and which are all in the form of natural casts, mostly of the interior of the shell. Therefore a figure only of one of his type specimens is given on plate 19. His original description is as follows : ‘Shell attaining a medium size, or larger, rather thin; longitudinally ovate, being somewhat less than twice as long as high, with the widest (highest) point in advance of the middle; rather distinctly convex; an- terior side wider than the other, and regularly rounded; posterior mar- gin nore narrowly rounded, or sometimes obliquely subtruneate above; basal outline forming a broad, semi-ovate curve, with the most prominent part in advance of the middle; beaks moderately depressed and placed between one-third and one-fourth the length of the valves from the an- terior margin; surface smooth, or only showimg marks of growth; car- dinal teeth prominent, and bearing, in internal casts, a very profound impression, ranging vertically just behind the anterior muscular sear; lateral teeth long and straight, two in the left and one in the right valve. “Length, 3.80 inches; height, 2.20 inches; convexity, 1.40 inches. ‘This will be readily distinguished from that I have provisionally re- ferred to, U. tellenoides Hall, by its proportionally longer and more convex valves, stouter hinge, and particularly by having larger, thicker, and more prominent cardinal teeth, ranging vertically instead of very obliquely forward and downward. “* Locality and position.—Chureh Buttes, Wyoming Territory; miocene [eocene] tertiary, in a rather coarse greenish grit.” Figure 1 a, on plate 19, is drawn from one of Mr. Meek’s types, which, although so imperfect, is one of the best examples yet discovered. Mr. Meek does not mention the group from which his specimens of this species were obtained, but as Church Buttes are composed of Bridger strata, they are doubtless from that group. The full charac- teristics of this species are not yet satisfactorily known, because its outer surface and complete external form have not been fully shown by any of the specimens yet discovered. It probably occurs at different hori- zons throughout the Green River Group also, but as the specimens of Unio found in all three of the Eocene fresh-water groups are so gener- ally in the form of casts, the identity of the forms referred to with this species has not been satisfactorily determined. Some examples, also, that have been discovered in the Wahsatch Group appear to belong to this species; but these, too, have been found only in the form of casts. GASTEROPODA. Genus PLANORBIS Miiller. PLANORBIS CIRRATUS White. Plate 19, figs. 5 a, b, and ¢. Planorbis cirratus White, 1879, An. Rep. U. 8S. Geol. Sur. Terr. for 1877, p. 251. Shell small, discoidal; volutions six or seven, very slender, their trans- verse diameter a little greater than their vertical, coiled closely and so nearly in a plane that the upper and under sides respectively are dis- tinguished mainly by the difference in the direction of the lines of growth upon the surface; the contact of the volutions is such as to produce a Slight concavity upon the inner side of each, all the outer and exposed ware. ] TERTIARY FOSSILS. 45 surface being regularly rounded and without revolving angles or lines. Surface smooth, or marked only by the ordinary striz of erowth. Diameter of the coil of the largest example discovered, 8 millimeters: transverse diameter of the last volution, 1} millimeters. This species is remarkable for its numerous slender and plain volu- tions and small size. It differs materially from any other species known to me, either fossil or recent, in the slenderness of the volutions and the almost exact plane of its coil. The aperture is apparently without any thickening or reflexure of the peristome, even when fully adult. Position and locality—It has been found only in strata belonging to the basal portion of the Green River Group, or to the upper portion of the Wahsatch Group, about three miles east of Table Rock Station, Union Paciiic Railroad, Wyoming. Genus PHYSA Draparnaud. PHYSA BRIDGERENSIS Meek. Plate 19, figs. 10 a and b. Physa bridgerensis Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, p. 516. The specimens from which Mr. Meek drew his description of this species having been lost or mislaid, the figures illustrating it on plate 19 have been drawn from opposite views of two specimens which were obtained from the Bridger Group in the valley of Henry’s Fork, a few miles east of Fort Bridger, by one of Professor Powell’s parties in 1875, They do not strictly agree in all particulars with Mr. Meek’s descrip- tion, but the discrepancy is probably due to the fact that his types were less perfect than our examples are. He, however, recognized the identity of the latter with his species upon an examination which he gave them at my solicitation a short time before his death, and there is probably no reason to question it. The fact that both, his types and our examples are from the same formation and the same region, also favors this view. The following is Mr. Meek’s description : “Shell attaining a large size, subovate in form; spire prominent, coni- cal; volutions four and a half to five, moder ately convex, last one large but not very ventricose; suture well defined; aperture narrow- subovate, arcuate, acutely angular above, and about twice as long as the spire; columella twisted into a rather prominent fold. Surface with fine sharp lines of growth. “Length about 1.15 inches; breadth, 0.66 inch. ce This i is a fine large species, with a ‘more prominent spire than any of our recent species ‘Tesemblin g it in other respects. None of the speci- mens found are perfectly preserved. “Locality and position—Church Buttes, fourteen miles from I ort Bridger, Wyoming Territory. Tertiary.” Genus SUCCINEA Draparnaud. Subgenus BRACHYSPIRA Pfeiffer. SUCCINBA (BRACHYSPIRA) PAPILLISPIRA White. Plate 19, fig. 4 a. Succinea papillispira White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 129. Shell rather small, ovate or subelliptical in lateral outline; spire minute but prominent; last volution expanded and broadly convex ; 46 GEOLOGICAL SURVEY OF THE TERRITORIES. aperture large. Surface marked by the ordinary lines of growth, and, under the lens, faint, close-set, revolving striz are seen crossing the fine lines of growth, giving the surface a fine cancellated appearance. Length 11 millimeters; breadth accross the middle of the aperture 6 millimeters. There areat best only a few salient specific characteristics observable in the shells of any species of Suecinea, but this shell may be regarded as distinguished from all other species with which it is in any danger of being confounded by its minute spire, the very abrupt spreading of the body volution, or rather part of a volution, from those of the spire. Figure 4 a, plate 19, is drawn from a gutta percha cast of a natural mould in fine-grained sandstone, the latter having been a little distorted by pressure. i This species.was discovered by the writer in the summer of 1875, and up to the present time no other fossil species of the genus Succinea has been discovered in North American strata. The discovery of a repre- sentative of this genus among the early Tertiary pulmonate mollusea is an interesting one; and the interest 1s increased also by the evidence which it affords that the subgenus Brachyspira of Pfeiffer was estab- lished as a subgenerie type as early, at least, as the Hocene epoch. Position and locality y.— Upper Green River Group, Alkah Stage Station, some twenty miles northward from Green River City, Wyoming, at which locality alone the species has yet been discovered. Conus PUPA amare PUPA ARENULA White. Plate 19, figs. 8 a and b. Pupa arenula White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 131. Shell minute, ovate; spire obtusely rounded, its apex slightly promi- nent or merely convex; volutions, five or six, moderately convex; suture impressed; last volution contracted near the aperture; border of the aperture apparently reflexed, but its true shape, and the character of the armature, if any, of the aperture, unknown, in consequence of the imperfection of the specimens. Length, 2 millimeters ; diameter, 14 millimeters. This shell, in shape, size, and general aspect, closely resembles Vertigo ovata Say, among living Pupide. It appears, however, to be either Pupa proper, or referable to the subgenus Pupilla. Position and locality—Upper Green River Group, valley of Henry’s Fork, southward from Green River City, Wyoming, where it is asso- ciated with the two species next described, and also with Physa, Planor- bis, &e. PUPA ATAVUNCULA (sp. nov). Plate 19, fig 9 a. Shell minute, elongate subovate; the sides of the spire, for greater part of its length, subparallel; the distal portion of the spire, together with the apex, obtuse; volutions about five, convex, gradually inecreas- ing insize; suture impressed. Aperture unknown, but it is apparently not contracted. Length about 14 millimeters; diameter, 1 millimeter. ware.) TERTIARY FOSSILS. AT This species very closely resembles, both in size and shape, Pupa cali- fornica Rowell, as figured and described by Binney and Bland in Land and Fresh-Water Shells of North America, part I (Smithsonian Miscel- laneous Collections 194), p. 239, fig. 413. These authors give the diame- ter of that shell as one millimeter, which is the same as that of ours; but they state its length ‘to be two and a half millimeters, which is one-fourth longer than the proportions of their figure indicate. I have never seen an example of that shell, but their figure (loc. cit.) probably correctly represents its proportions, which are therefore nearly the same as those of our shell. Indeed it is difficult to say, with the present knowledge only of our shell, wherein it differs from P. californica, but as no living species have been found in the strata from which the former comes, and as all its characteristics are not yet known, it would probably not be warrantable to refer it to a living species. It differs conspicuously from the last-described species, P. arenula, with which it is associated, and with which it corresponds approximately in size by being much less globose, and apparently in not having its aperture contracted. It has the aspect of the typical forms of Pupilia, and ought probably to be referred to that subgenus. Position and locality—Upper Green River Group, Henry’s Fork, Wy- oming, where it is associated with the following as well as with the pre- ceding species, and also with other pulmonate gasteropods. Subgenus LEUCOCHBEILA Albers. PupA (LEUCOCHEILA) INCOLATA White. Plate 19, figs. 7 a, b, and c. Pupa incolata White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 130. Shell small, elongate, distinctly rimate, sides somewhat regularly ta- pering along the greater partof the length of the shell, but inore rapidly converging at the extremity to a slightly obtuse apex; volutions about Six; convex regularly increasing from apex to aperture, the last one not contracted ; suture impressed ; aperture subovate in outline, its length a little more than one-third that of the whole length of the shell; outer lip thickened, prominent, reflexed ; aperture apparently without either teeth or folds, but the condition of all the specimens in the collection is unsatisfactory in this respect. Length, 5 millimeters; diameter of last volition, 2 millimeters. This species closely resembles in size, form, and general characteris- tics, Pupa (Leucocheila) fallax Say, but the sides of our shell converge at a somewhat greater angle than they do in Say’s species, and its peri- stome is also more thickened and expanded. It appears to possess all the characteristics of the subgenus Leucocheila ; or at least it differs sub- generically from the typical forms of Pupa. The fact that we find two, and perhaps three, subgeneric forms of the Pupide in the Eocene strata of Western North America, is of great interest as regards the question of the early differention of existing types of pulmonate mollusks. Position and locality—Upper Green River Group, valley of Henry’s Fork, southward from Green River City, Wyoming, where it was found ae with the two preceding species, and also with Helix, Planorbis, C. 48 GEOLOGICAL SURVEY OF TH LERRIT°OVIES. Genus BYTHINELLA Moguin-Ta don. BYTHINELLA GREGARIA M :k. Plate 19, figs. 6a and 60. Bythinella gregaria Meek, 1871, An. Rep. U. S. Geol. Sur. Terr. for 1870, p. 317. The following description and remarks of Mr. Meek embrace all that has yet been learned concerning this species: ‘¢ Shell small, conoid-subovate; spire rather elevated; volutions five, rounded or very convex; suture strongly impressed; aperture ovate or slightly longer than wide, with the upper extremity subangular, and the lower rounded; inner lip not reflected, and leaving by its side a very small umbilical impression that seems not to perforate the axis. Surface smooth, or only showing, under a strong’ magnifier, very minute lines of growth. “ Length, 0.15 inch; breadth, 0.08 inch ; length of aperture, 0.06 inch; breadth of aperture scarcely 0.04 inch. “This little shell so nearly resembles in form and proportions the fig- ures of Bythinella tenuipes of Couper, that it is with some hesitation I have concluded to regard it as a distinet species. As that shell, how- ever, is described as having its suture ‘slightly impressed,’ and as being ‘subumbilicated’ while that under consideration has its suture very deep, and could not be properly described as even swbumbilicated, I do not feel warranted in referring our Tertiary form to the existing species. ‘‘Of course we have no certain means of determining whether we ought not to call this shell Amnicola gregaria, or Pomatiopsis gregaria, instead of referring it to Bythinella, the distinction between these two groups being mainly based on characters not apparent in the shell. The fact, however, that it is found in vast numbers associated with a small Plan- orbis and millions of the carapace-valves of a minute Cypris, would seem to indicate that it was aquatic in its habits, like Bythinella and Amnicola. It is true terrestrial shells are often swept by_streams into lakes, and deposited along with those of aquatic species; but it is exceedingly im- probable that millions cf so small a shell as this would have been de- posited all together, so as almost to form an entire bed of limestone, es- pecially without some other terrestrial types. 3 “6 Locality and position.—Pacifie Springs [Wyoming], Tertiary.” Fic. 1. Fig. 2. Fig. 3. Fig. 4. Fic. 5. Fig. 6. Fic. 7. Fie. 8. Fie. 9. Fig. 10. PLATE 19. UNIO MEEKII. 22.222 co. eee ---- oe noe ce cee ee enn een ee een e ee teeeee : a. Natural cast of the interior of the left valve; natural size. UNIO SHOSHONENSIS..---------- ---- e----2 ---- ---- - === +--+ noe === a. Left valve; natural size; from Southern Wyoming. b. Left valve of another, more elongate example; from White River Valley, Northwestern Colorado. UNTO, WASHAKIENGIS. 12005-0000 RRS elena a. Left valve ; natural size; from near Fort Bridger, Southern Wyo- ming. b. Left valve of another example; anatural cast in sandstone; from White River Valley, Northwestern Colorado. SITGGUNTAUPAPILLISPIRA 5.21 1g We sents sigan ue ever ny CO Gene a. Lateral view; enlarged two diameters, of a gutta-percha cast of a natural mold in fine- grained sandstone. The specimen has been a little distorted by accidental pressure in its preservation. PLANORBIS CIRRATUS...---..----- -- SiS eeee a eave ee ea ta ol antays everett a. View of the upper side; enlarged to two diameters. b. View of the under side of the same. c. Peripheral view of the same, showing the outline of the aperture. IBYAUSIONI NITION CIINKEVNUN Sons ogoqde coacua donded bono ad bo Sa sodscoceasas a. Apertural view; enlarged to four diameters. b. Opposite view of another example similarly enlarged. IPOD TOSOOIONUNN Goo6 cn oce5 oso0 sac oSos0505 0050d6 Se Sbeee0 So OSeueN cose a. Apertural view; enlarged to four diameters ; showing the aperture filled with a portion of the stony matrix. b. Opposite view of the same. c. Another view of the same, showing the thickened edge of the outer lip. IPUPAY ARENUDIAG 2 2c aacia ost iee oernete a eee ere e lees jase eee seer a. Apertural view; enlarged to four and a half diameters; the per- istome broken away. b. Opposite view of the same. JOGA, ASBAQVOINGU o655 Sooncn co Gud6 coo Se HoS6 acKO ON d6S0 so09 060060 onde a. Lateral view; enlarged to six diameters. PHYSA BRIDGERENSIG 2a soe ae Sc ya eS aie causing eee eed a. Apertural view ; natural size; a part of the outer lip broken away. b. Opposite view of another, more robust example. Page. 43 45 44 48 47 46 46 45 ~ 74 mA, av TERTIARY. 19. PLATE U.S.GEQLOGICAL SURVEY om, Lith 2, Sinel -Holmes del F.D. Owen & W.H CONTRIBUTIONS TO INVERTEBRATE PALEONTOLOGY NO. 4: FOS- SILS OF THE LARAMIE GROUP. Bye ©. Aq Write. Mi. 1D: The illustrations which accompany this article, on plates No. 20 to No 30, inclusive, have from time to time been prepared to accompany a pro- posed monograph of the Laramie Group and its Invertebrate Fauna. A large amount of materials and the results of extended observations had been collected towards such a monograph up to the time that the field- work of this survey was discontinued, but the original plan of publica- tion of these results has been abandoned because extended field investi- gations and large collections would be necessary to the completion of such a work upoh a plan commensurate with its importance. The dis- continuance of this survey having made it necessary to abandon the original plan, the material now accumulated is published in this article as one of the series of Contributions to Invertebrate Paleontology. The Laramie Group and its invertebrate fossils have been frequently discussed by me in certain of the publications of this Survey during the past four years; and as there is some want of harmony in relation to some of the views expressed, or of inferences that may be drawn from statements made, or from methods of treating the subject in those pub- lished articles and reports, those publications may be taken to indicate the progress of our knowledge concerning the subject discussed. This was necessarily the case, because the field is so large and because the subject embraced the investigation of a great group of strata which has no known equivalent in other parts of the world. While future investiga- tions will no doubt. add greatly to our knowledge of the Laramie Group land itsinvertebrate fossils, and perhaps considerably modify the views at present entertained, the two following-named publications besides this one may be taken as containing an exposition of my views at the present time: Pages 255-265 of the Annual Report of this Survey for 1877; and article xxxvi, volume iv of the Bulletin of this Survey. As the general subject has been somewhat fully discussed in these two pub- lications, the present article will be confined to the following general summary, and to the enumeration of the known invertebrate fossils of the group, together with the description of those which are illustrated on the eleven accompanying plates before designated. The geographical limits of the Laramie Group are not yet fully known, but strata bearing its characteristic invertebrate fossils have been found at various localities within a great area, whose northern limit is within the British Possessions, and whose southern limit is not further north than southern Utah and northern New Mexico. Its western limit, so far as known, may be stated as approximately upon the meridian of the Wahsatch range of mountains, but extending as far to the south- westward as the southwest corner of Utah, and its eastern limit is far out on the great plains, east of the Rocky Mountains, where it is cov- ered from view by late formations and the prevailing débris of the 50 GEOLOGICAL SURVEY OF THE TERRITORIES. plains. These limits indicate for the ancient Laramie sea a length of about one thousand miles north and south, and a maximum width of not less than five hundred miles. Its real dimensions were no doubt greater than those here indicated, especially its length; and we may safely as- sume that this great brackish-water sea had an area of not less than fifty thousand square miles. The present range of the Rocky Mount- ains, which has been entirely raised as a mountain range since the close of the Laramie period, traverses almost the entire length of this great area, and far the greater part of the other extensive and numerous dis- placements which the strata of the different geological ages have suffered within that great area have also taken place since all the Laramie strata were deposited, although some of those changes thus especially referred to began before the close of the Laramie period. Itis for these reasons that the great region within which the strata of the Laramie Group are found, however much they may be now displaced, is assumed to have been entirely covered by the Laramie sea during the whole of that period, except such portions as rose above the surface by stratigraphical dis- placements before its close, as before intimated. * The invertebrate fauna of the Laramie Group consists almost wholly of brackish-water, fresh-water, and land mollusea. Species belonging to all three of these categories are often found commingled in the same strata, but it is also often the case that certain strata, sometimes only thin layers, which contain the fresh-water and land mollusks alternate with those which contain the brackish-water species. With the excep- tion of one species of Axinca, one of Nuculana, and one or two of Odonto- basis, no species usually regarded as of marine types have been found in any of the strata of the Laramie Group;t and even these are doubtless such as became inured to a brackish-water habitat as the waters were progressively freshened, just as certain marine types of fishes and other aqueous animals have become inured to brackish and even fresh waters both in past geological epochs and at the present time. Such brackish- water types, however, as Ostrea, Anomia, Corbula, Corbicula, and Neritina characterize the Laramie strata throughout their whole geographical extent, and from top to bottom of the group. Indeed this brackish- water fauna is the great distinguishing feature of the Laramie Group, so far as its remains of invertebrate life are concerned, and all the genera just named, except the last (the representatives of which are compara- tively rare), are abundantly represented from the base to the top, or near the top, of the group. All the species of fresh-water and land mollusea which prevailed during the Laramie period seem to have ceased with the disappearance of their contemporary brackish-water forms, although they were succeeded by other fresh-water and land species; so that we find it convenient and proper to fix the latest limit of the Laramie Group where the brackish- water forms disappear, especially so because no brackish-water forms are known in all that great western region in strata later than those of the Laramie Group. It is, however, quite proable that some species of the fresh-water and land mollusca of the Laramie period continued to live after its waters were fully freshened and all brackish-water forms had disappeared, but no instances of a commingling of those Laramie fresh * The frequent alternation of strata in the Laramie Group which contain only fresh- water molluscan forms with those which contain brackish-water forms, and the proba- ble conditions which produced that result are discussed in the two publications cited on the preceding page. t The reference of Znoceramus and other marine forms to strata of this group (= Point _ of Rocks Group of Powell), in chapter iii, Powell’s Report on the Geology of the Uinta Mountains, was the result of error in stratigraphical determinations. WHITE. | LARAMIE FOSSILS. 51 water mollusks with the fresh-water forms which characterize the Wah- satch and other purely fresh-water groups above the Laramie have yet been observed. But if sedimentation was continuous from the Laramie, to the Wahsatch Group, as it is believed to have been, we may reason- ably expect to find such a commingling of species at least in the lower strata of the Wahsatch Group or the top of the Laramie. Paleontologically the Laramie Group stands out clearly and dis- tinetly from the marine Fox Hills Cretaceous Group beneath, and the purely fresh-water formations above it, even though they may be con- nected by certain faunal types in the manner suggested. Its zodlogical characteristics are such also as to mark the Laramie as a well-defined period in geological history, apparently quite codrdinate in importance with all that portion of the preceding Cretaceous period, which is rep- resented by any and all North American strata which have been referred to that period. The stratigraphical relations of the Laramie Group I have discussed at length in the works already cited, and I need only eall attention here to the unique character of its invertebrate fauna, as ex- hibited in this article and the accompanying illustrations, not only as regards the relation of the latter to the faunv of the formations which respectively underlie and overlie it, but as regards any other known faune. The unique character of this Laramie fauna is not affected by the fact that a large proportion of its types, especially those of its fresh- water and land mollusks, are evidently the genetic precursors of some of those now living in North American fresh-waters, because compari- sons are made with that fauna in its entirety, and with it as regards its position in geological time. ‘There are other brackish-water deposits among the strata of that great western region, especially those of Cre- taceous age, but these are of comparatively small extent and contain limited faune the species of which at least are different from those of the Laramie Group, which latter fauna evidently lived in a great brackish- water sea. Those limited faune are mentioned here for the purpose of pointing out the fact that they are not to be confounded with the Lar- amie fauna, whatever genetic relations they may have sustained to it in fact, and in the order of time. The evidence as to the true geological age of the Laramie Group has also been discussed in the two former publications before cited, and there- fore only a brief summary of that question will be given in this article. Among the vertebrate remains that have hitherto been discovered in its strata are some of distinctively Cretaceous types as judged by European standard, namely, the Dinosaurian. Therefore vertebrate paleontologists have generally regarded the Laramie Group as of Cretaceous age. Paleo- botanists, however, have quite as generally regarded the vegetable re- mains of the group as belonging to Tertiary types. Among all the inver- tebrate fossils which have yet been discovered in the strata of the Lara- mie Group, none of the types are distinctively characteristic of the Cre- taceous period according to any hitherto recognized standard. Many of the molluscan types of this group still exist, although the species are of course extinct, and some of those types are known to have existed. during the Cretaceous epochs preceding the Laramie. But on the other hand four or five molluscan genera and subgenera have been recognized in the fauna of the Laramie Group that are not known beyond its limits. In view of the fact that the known Cretaceous flora of North America has near affinities with European Tertiary types, some persons regard the Tertiary facies of the Laramie flora as presenting little objection to a reference of that group to Cretaceous age. To those who hold such views the balance of paleontological evidence seems to be in favor of 52 GEOLOGICAL SURVEY OF THE TERRITORIES. such a reference, especially as the strata immediately overlying that group contain an abundance of mammalian remains of Hocene-Tertiary types, while no such mainmalian types occur in the Laramie Group. The following facts, however, favor the view which I have advocated, that the Laramie is really a transitional group between the Cretaceous beneath and the Tertiary above. We have yet no knowledge of the existence of any Cretaceous strata in North America which, according to Huropean standards, are equiva- lent with any part of the Lower Cretaceous of Europe; all known Cre- taceous strata of this continent being usually regarded as of the age of the Upper Cretaceous of that part of the world. The Fox Hills Group has consequently been regarded as equivalent with the latest Cretaceous of Hurope, a conclusion which is sustained by the character of its fossil fauna. The Fox Hills Group of Western North America is evidently exactly equivalent with the upper portion of the Cretaceous deposits of the Gulf and Atlantic States, where the marine Hocene deposits rest directly and conformably upon the Creta- ceous, with no intervening strata that can be regarded as paleontologic- ally equivalent with the Laramie Group. If, therefore, these parallel- isms are correctly drawn, asthey appear to be, the Laramie, as a complete group, cannot be as old as the latest recognized Cretaceous strata in either this or any other part of the world. Again, if those three groups of fresh-water strata which immediately overlie the Laramie Group, namely, the Wahsatch, Green River, and Bridger Groups, are really of Hocene-Tertiary age, as they are accepted by all paleontologists to be, then is there additional evidence of the correctness of the view that the Laramie is a transitional group between the Cretaceous and the Ter- tiary, partaking of the faunal characteristics of both periods. It should also be stated that paleontologists have generally agreed in referring the Wasatch, Green River, and Bridger Groups to the earlier Hocene. In the two publications before cited I have shown that the strata of the Judith River and Fort Union series of the Upper Missouri River region; the lignitiec series east of the Rocky Mountains in Colorado and the adjacent region, and the Bitter Creek series and its equivalents west of the Rocky Mountains in Wyoming and Colorado, which were formerly treated as separate groups, are all merely regional divisions of the great Laramie Group, all being faunally connected together by the specific identity of a considerable proportion of their fossil remains.* In those publications I also included in the great Laramie Group that series of strata which have become well known as the Bear River series, its best known development being in the valley of Bear River, in the southwestern part of Wyoming, but equivalent strata being known many miles to the northward of that valley, and also at intervals in the region of the Wahsateh range of mountains as far south as Southwestern Utah. That portion of this Bear River series, that is, the lower portion, which is of brackish water origin, contains a molluscan fauna, every known species of which is distinet, not only from those of other forma- tions, but different from any that are found in any of the other portions or regional divisions of the Laramie Group, before mentioned. This difference is evidently too great to be considered as a mere regional variation of the prevailing fauna of that period, and it becomes a serious question whether we ought not to regard that Bear River series and its * Professor Cope’s investigations of the vertebrate remains in these various regions have also shown that these regional divisions of the strata which are here referred to the Laramie Group all belong to one great and important geological period. wate. ] LARAMIE FOSSILS. 53 faunal equivalents as at least a separate division of the Laramie Group, . if not, indeed, as a separate group. The plan of the formerly-proposed monograph of the Laramie Group, which has already been mentioned, contemplated a separate discussion of the fauna of the Bear River series, but that plan cannot be strictly adhered to in this article, because its fauna has not yet been sufficiently investigated to reveal its true relation with that of the great remainder of the Laramie Group. Therefore only the following brief summary of our present knowledge of that portion of the subject will be given in this articie, together with some suggestions which the facts stated seem to warrant. The consideration of this subject will be somewhat facili- tated by reference to plate 30, which contains illustrations of rossils of the Bear River series only, while the other plates pertaining to this article contain figures of such fossils only as are found in the typical portion of the Laramie Group. The continuity of the strata ofthe Bear River series with those of the great body of the Laramie Group elsewhere has never been traced, and such con- tinuity is not really known to exist; but that series has been referred to the Laramie Group, notwithstanding the contrast presented by its fossil re- Mains, mainly because it is, like the other, a great brackish-water deposit, and because it is everywhere found to be bounded, respectively, above and below, by the same formations that thus bound the typical portion of the group. All geologists are agreed that the Laramie Group is every- where conformable with the Fox Hills Cretaceous Group, which lies be- neath it, and none deny that in the production of the strata of the two groups sedimentation was or that it may have been continuous from the lower of these groups to the upper. With regard to the relation of the Laramie Group with the overlying Wahsatch Group of the Tertiary period, there is considerable diversity of opinion, some claiming that the two groups are everywhere uncomformable, and others, that they are in some places entirely conformable, and perhaps were there continu- ously deposited. I entertain this latter view, for which I have given my reasons in the former publications before cited. This conformity of the upper strata of the Laramie Group with the lower sirata of the Wahsatch has, however, been observed by myself only in the case of the Bitter Creek series and its equivalents, in Southern Wyoming and Northwestern Colorado, and in that of the lignitic series, east of the Rocky Mountains, in Colorado; while the Wahsatch strata that rest upon the Bear River Laramie series in the region of its typical exposures are known to be distinctly unconformable, and in most places very greatly so. From all information, also, which I have been able to gather from the observations of other geologists in addition to my own, the strata which rest upon the equivalents of the Bear River Laramie series, both northward and southward from the typical localities, are everywhere unconformable. The following facts, gathered from the sources referred to, lead me to believe that the great displacements which caused this unconformity took place before the close of the Lara- mie period, and not at its close, as claimed by some authors. I have never visited Central and Southern Utah in person, but the different parties connected with the surveys under the direction, respectively, of Lieutenant Wheeler and Professor Powell have brought in a number of species of Laramie fossils from different localities in that Territory, some of which are charasteristic of the Bear River series, and others are equally characteristic of other portions of the great Laramie Group. From the information which I have received in connection with these 54 GEOLOGICAL SURVEY OF THE TERRITORIES. collections, I am led to believe that all the first mentioned species are from the highly disturbed Laramie strata, while the latter are from those which lie unconformably upon the disturbed strata, and which have been generally regarded as Lower Tertiary beds by the geologists who have examined that region. Whether this latter view is correct or not it is certain that the strata of the Bear River division of the Laramie Group, are found to be displaced to a greater extent than any of the other strata which are referred to that group. The coal-bearing series near Evanston, Wyo., which in the report of this survey for 1877 I referred to the Laramie Group, appears, at that place, to rest conformably upon the brackish-water series, or the Bear River Laramie proper; but of this I was not then, and am not now, en- tirely satisfied. Those coal-bearing beds of the vicinity of Hivanston are probably equivalent with the coal-bearing beds at Wales, Utah, which latter beds are understood to belong to a series of strata which are ex- tensively developed in various parts of Utah, and which some. geolo- gists who have examined them regard as overlying more or less uncon- formably the equivalents of the Bear River Laramie series, and which are referred by them to the lowest Tertiary. Those Wales beds, however, contain at least two species, namely Goniobasis nebrascensis and G. tenui- carinata, which occur in the Laramie strata of the Upper Missouri River region, and also in those of Colorado east of the Rocky Mountains; and J showed also in the report of this survey for 1877 that the Evans- ton coal-bearing series contains other Laramie species which were orig- inally discovered in the Upper Missouri Liver region. As it is not my purpose, however, to discuss in this article the true character and rela- tions of those coal-bearing beds at Evanston and Wales and the Upper Kanab beds, all of which contain at least some Laramie species, I shall give in addition to the list of well recognized Laramie fossils only sep- arate unannotated lists of the supposed Laramie invertebrate fossils of other localities. The coal-bearing Evanston beds occurring at the only one of the supposed Laramie localities above mentioned which I have visited and examined in person, I give the lists from the other locali- ties upon the authority of other observers. Tt will thus be understood that [ am omitting from this article the discussion of some of the most important questions pertaining to the Laramie period, namely, the question of its continuance after the occur- rence of the great and extensive displacements which involved the strata of the Bear River brackish-water series and its equivalents; that of the original geographical continuity of the upper beds at Evanston, Wales, and Upper Kanab with the great body of the Laramie Group further eastward, and that of the continuity of deposition of the latter beds with the Wahsatch Group. The question of the true relation of the Bear River brackish-water beds with the great body of the Laramie Group has here also only a small part of the discussion which its importance demands. It is the great importance of these questions and the lack of sufficient opportunity to continue personal investigations of them in the field, that leads me to lay them aside now and wait for a suitable op- portunity to prosecute their investigation in a proper manner. The following is a list of the species that have been described from the coal-bearing beds of Bear River Valley in the vicinity of Evanston, Wyo., together with those which were originally described from other localities, but have been identified among the fossils of those beds. WHITE.] LARAMIE FOSSILS. 55 LIST OF FOSSILS FROM THE COAL-BEARING BEDS NEAR EVANS- TON, WYO. Pisidium saginatum White. tBulinus disjunctus White? *B. subelongatus Meek & Hayden. *B. longiusculus M. & H. Helix evanstonensis White. Macrocyclis spatiosa M. & H. *Columna teres M. & H. Hydrobia recta White. Those marked with an asterisk were originally discovered in unques- tioned Laramie strata. It will be seen that they are all Pulmonate Gasteropods, the significance of which fact I have pointed out in my former writings concerning the Laramie Group. Among the collections brought from Southern Utah by Professor Powell are the following, which evidently belong to the Laramie Group, and they are believed to have been all collected from strata which overlie unconformably those strata in that region which are properly referable to the Bear River Laramie series. Only the first and second forms of this list are illustrated in this article. LIST OF FOSSILS FROM UPPER KANAB, UTAH. tUnio gonionotus White. *Corbula undifera Meek, var. subundifera White. Planorbis (Bathyomphatus) kanabensis White. Physa kanabensis White. Helix kanabensis White. The collections of Professor Powell from the same neighborhood con- tained also some fossils that evidently came from strata referable to the Bear River series, and doubtless belonging beneath those which contain the fossils of the foregoing list. Among them Goniobasis cleburnt and Pyrgulifera humerosa were recognized. The collections brought in by one of the parties under the direction of Lieutenant Wheeler contain the following fossils, which are described and figured in Expl. & Sur. West of the 100th Merid., vol. iv, parti, hav- ing been obtained from the coal-bearing beds at Wales, Utah. ‘This col- lection is especially interesting, although so small, because it contains two species which are characteristic of the typical portion of the Laramie Group in Montana and Colorado. LIST OF FOSSILS FROM THE COAL-BEARING STRATA AT WALES, UTAH. Unio mendax White. Goniobasis nebrascensis Meek & Hayden. G. tenuicarinata M. & H. Viviparus ———? U. mendax was referred by me to U. vetustus Meek, in vol. iv, Expl. & Sur. West of the 100th Merid., but, afterward regarding it as a distinct species, I gave it the name U. mendax, in Bull. U.S. Geol. Sur. Terr., vol. iii, p. 605. This species, together with Goniobasis nebrascensis, and a Viviparus closely related to, if not identical with, V. trochiformis M. & H., were also recognized among the fossils of a collection brought tThese two species are illustrated in this article; the former on plate 20, and the latter on plate 28. 56 GEOLOGICAL SURVEY OF THE TERRIEORIES. from the Cation of Desolation, Green River, Utah, by Professor Powell; the strata there being evidently equivalent with those at Wales. Omitting special consideration of the fossils of the foregoing brief lists, although they are believed to really belong to the Laramie Group, the plan of the remainder of this article will embrace an enumeration of all the well-ascertained invertebrate species of the Laramie Group, inelud- ing those of the Bear River series. Full descriptions, however, are given in this article of those species only which are illustrated upon the accompanying plates. For the purpose, however, of giving a’ full ex- hibit of the well-recognized molluscan fauna of the Laramie Group, the names of all the other species are given in systematic order, with vefer- ences under each to the work or works in which descriptions and illus- trations of them may be found. ‘This article will thus present a synop- sis of the invertebrate fauna of the Laramie Group, as it is known at the present time. It is a conspicuous fact that the invertebrate fauna thus presented consists wholly of mollusca. The only known examples ot forms which do not belong to this class, that have been found in this group, are a few small Ostracoid Crustaceans, and some egg-masses of an insect described by Mr. Scudder under the name Corydalites fecundum, in 1878, in Bull. U.S. Geol. Sur. Terr., vol. iv, pp. 537-540.* — Besides the described species herein enumerated, there are known frag- ments of some others which are too imperfect for specific description ; and in view of the fact that every season’s examination of the strata of this great group in the field has brought to light new forms, we may safely conclude that many more will yet be added to the already inter- esting and important invertebrate fauna of the Laramie Group. CONCHIFERA. Genus OSTREA Linneeus. OSTREA GLABRA Meek & Hayden. Ostrea glabra Meek & Hayden (1857), 1876, vol. ix, U. S. Geol. Sur. Terr. (4to ser.), p. 509, plate 40, figs. 2, a, b, c, and d. Ostrea wyomingensis Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, p. 508. Illus- trated on plate 20 of this article. Osirea arcuatilis Meek, 1873, An. Rep. U. S. Geol. Sur. Terr. for 1872, p. 477. Ostrea insecuris White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 112. Illustrated on plate 21 of this article. Compare Ostrea subtrigonalis Evans & Shumard, 1857 (redeseribed and illustrated by Meek), vol. ix, U. S. Geol. Sur. Terr. (4to ser.), p. 510, pl. 40, figs. 1, a, b, ¢, and d. By the foregoing synonymy it will be seen that I refer all the forms of Ostera yet described from the Laramie Group to one and the same species, except, perhaps, O. subtrigonalis, the reasons for which may be found stated upon pages 162, 208, and 217 of the report of this survey for 1877. The first and fifth forms are figured by Meek in vol. ix, pl. 40, U.S. Geol. Sur. (4to ser.). The second and fourth forms are illustrated on plates 20 and 21, which accompany this article, but the third is not vet illustrated. It is plainly only a variety of the variety O. wyomingen- sis, with typical forms of which it is associated. A small Ostrea oceurs not unfrequently in the Bear River Laramie series, which is probably a distinct species, but no examples sufficiently characteristic have yet been obtained. * These interesting objects will be discussed by Mr. Scudder in his forthcoming work, Tertiary Insects of North America, and figured on plate 4, accompanying that work, figs. 4-7, 13-16, 18-21, and 23. WHITE. ] LARAMIE FOSSILS. 5T Genus ANOMIA Linneeus. ANOMIA GRYPHORHYNCHUS Meek. Plate 25, figs. 1, a, 6, and ec. Anomia? gryphorhynchus Meek, 1872, An. Rep. U. S. Geol. Sur. Terr. for 1871, p. 375 Anomia (Placunopsis ?) gryphorhynchus Meek, 1873, An. Rep. U.S. Geol. Sur, Terr. for 509. Cs 10e The follow ile is Mr. Meek’s description of this species, as given in the second place above cited : “Shell, for an Anomia, of medium size,thin and pearaceous s, a little obliquely subovate, or more or less orbicular in outline, usually somewhat narrowed towards the beak, and more broadly rounded at the opposite margin, often rather convex, ‘but variable in this respect; cardinal margin arcuate transversely, or very slightly truncated, scarcely thicker than other parts of the shell, and without any proper marginal cardinal facet. Upper valve (assuming it to be an Anomia), in the more ventricose in- dividuals, with umbo somewhat attenuated and curved, so as to present the appearance of the under valve of Gryphwa, except that the obtuse immediate apex is not quite marginal. Surface usually appearing smooth, but in well-preserved specimens, especially those most depressed in form, sometimes very faint traces of fine radiating striz, and thin, raised lamellz of growth may be seen. No scars of attachment observed on any of the specimens. ‘* Length and breadth of an orbicular specimen, 0.83 inch; convexity of same, 0.33 inch; breadth of an oval specimen of the same length, 0.63 inch; while there are all gradations between these extremes of form “In first describing this species Iwas unable to see any traces of mus- cular scars in any of the specimens then studied; but many of those since collected show them very clearly. They are precisely as in Anomia; that is, there are four impressions, one small one by the side of alittle submarginal cartilage pit, close up under the beak, and three others near the middle of the valve, the largest one of the latter being nearest the cardinal margin, and the two smaller ones just below the large one. ‘These three central scars are more or less nearly circular or oval, and usually distinct from each other, but sometimes in contact or nearly blended together. “Locality and position—Two miles below Point of Rocks (Union Pa- cific Railroad), Wyoming, Bitter Creek series.” This species occurs quite abundantly at the limited locality, where it was originally discovered; but I have also found it in Laramie strata holding a higher position in the Bitter Creek series, at Black Buttes Sta- tion, in Yampa Valley, near Cafion Park, and also in Crow Creek Valley, east of the Rocky Mountains, Northern Colorado. It is, however, a rare form, compared with the one next described, at all others than the first- named locality. Professor Powell also obtained a specimen, apparently of this species, from the cafion of Desolation, Green River, Utah. ANOMIA MICRONEMA Meek. Plate 25, figs. 2, a, b, c, and d. Anomia micronema Meck, 1875, Bull. U. 8. Geol. Sur. Terr., 2d Ser., No. 1, p. 43. The following is Mr. Meek’s original description of this species in the place above cited: ; “Shell of medium size, thin, orbicular, subovate, or somewhat irregu- 58 GEOLOGICAL SURVEY OF THE TERRITORIES. lar; upper valve moderately convex, more or less depressed, and nearly but not, quite marginal; cardinal margin generally a little truncated, and slightly thickened; surface ornamented by very fine, regular, often deflected, radiating striz, and small, sometimes regularly disposed con- centric marks of growth. Under valve unknown. ‘Diameter of well developed specimens, generally about one inch. ‘This species is quite abundant, and generally moderately well pre- served at the locality. As usual with fossil species of the genus, only upper valves were found. These show the muscular impressions to be exactly as in true Anomia. ‘“¢ Locality and position—From a shaft sunk on the Kansas Pacific Railroad, two hundred miles east of Denver, Colo., 45 feet below the surface, from beds of the age of the Wyoming Bitter Creek Coal series.” This Anomia has proved to be one of the most widely dispersed and abundant species of all that pertain to the Laramie Group, being especially common in the valleys of Bitter Creek and Yampa River, west of the Rocky Mountains; and also in the various fossil localities of that group east of the Rocky Mountains in Colorado. It is also known to range throughout the whole thickness of the group, a maxi- mum of at least three thousand feet. The species shows not only the usual great variation of form common to all Anomias, but also as regards the character of the radiating lines which mark the surface. In some cases, even in well-preserved examples, the radiating lines are obsolete or wanting. Others have those lines much coarser than the average; and the examples thus varied are found associated with an abundance of those which are normally marked. The examples which are figured on plate 25 have been selected for the purpose of showing this variation of surface markings. Considerable difference in average size and in general form has also been observed at different localities, which differ- ences were doubtless due to certain different conditions of environment while the mollusks were living. Thus, while at all the known localities of Laramie fossils east of the Rocky Mountains there is much variation as to the surface markings, there is comparatively little variation as to adult size and general form. But in the valleys of Yampa and White Rivers, west of those mountains, the specimens are generally much smaller; and in the strata at Rock Springs, in the valley of Bitter Creek, while the specimens are generally of the usual size, they have more than the average convexity of those found elsewhere. All these differences are, however, believed to be only varietal modifications of one species. Genus VOLSELLA Scopoli. Subgenus BRACHYDONTES Swainson. VOLSELLA (BRACHYDONTES) REGULARIS White. Plate 25, fig. 3 a. Volsella (Brachydontes) regularis White, 1878, Bull. U.S. Geol. Sur. Terr., vol. iv, p. 707. Shell arcuate-subovate in marginal outline; valves moderately con- vex; upper margin more or less strongly arched from the beak to the posterior portion; thence, with a continuous but stronger curve to the postero-basal margin, which is somewhat abruptly rounded to the gently concave base; front moderately narrow, slightly projecting beyond the beaks, and abruptly rounded to the base; beaks depressed, scarcely perceptible as such, and nearly, but not quite, terminal; hinge margin Short, nearly straight; umbonal slope somewhat prominent, but it is WHITE. ] LARAMIE FOSSILS. 59 conspicuous only because it increases the apparent concavity of the basal portion of the valve. Surface marked by numerous, rather coarse. radiating lines or small cost, which increase in size towards the free margins of the shell. These cost have generally a somewhat crenu- lated aspect, which is due, in part, at least, to small sinuosities in their course, and in part to being frequently crossed by lines and undulations of growth; denticles or crenulations of the short front margin distinct, but not large. Length of the type specimen, 36 millimeters; breadth at the widest part, 18 millimeters ; but several less perfect examples which have been obtained at different localities indicate a much larger maximum size, the largest of which must have had a length of about 65 millimeters. Position and locality.—The type specimen is from near the base of the Laramie Group in the valley of Crow Creek, Northern Colorado, about fifteen miles above the contiuence of that creek with Platte River. Other examples are from Cation Park, valley of Yampa River; Danforth Hills, near White River Indian Agency, Northwestern Colorado; and Rock Springs Station, Union Pacific Railroad, in the valley of Bitter Creek, Wyoming. VOLSELLA (BRACHYDONTES) LATICOSTATA White. Plate 25, fig. 4 a. Volselia (Brachydontes) laticostata White, 1878, Bull. U. S. Geol. Sur. Terr., vol. vi, p- 708. Shell transversely elongate, arcuate-subelliptical; upper border broadly and almost regularly arched; posterior border somewhat abruptly, but continuously rounded from the upper border to that of the base, which latter border is gently concave along its middle portion; front abrubtly rounded; beaks inconspicuous, situated near the front; hinge line short, nearly straight, not forming an angle with the remainder of the upper border; denticles or crenulations of the anterior border distinct but not large. Surface marked by the usual distinct lines of growth and also by fine radiating coste, which are obsolete along the whole length of the median portion of each valve, and are more distinct upon and near the dorsal border than elsewhere. Length, 50 millimeters; greatest width, 19 millimeters. This species differs conspicuously from V. (B.) regularis, in having a greater proportionate length, straighter and less crenulate cost, and in the absence or obsolescence of the latter upon the middle portion of the valves. : Position and locality.—Laramie strata, about four hundred feet from the base of the group; Danforth Hills, near White River Indian Agency, Northwestern Colorado. Genus AXIN AVA Poli. AXIN/A HOLMESIANA White. Plate 20, figs. 2 a and b. Shell subeireular, the height and width being nearly equal; ligament area of moderate size, well defined, and marked upon each side of its median line by about seven distinctly divaricating linear grooves; beaks moderately gibbous, obtuse; hinge somewhat strongly arched; lateral teeth six or seven in number on each side, moderately strong, straight 60 GEOLOGICAL SURVEY OF THE TERRITORIES. or only very slightly curved, their direction nearly transverse; the pits between them in all cases equaling the teeth in width; the teeth which occupy the median portion of the hinge, consisting only of numerous small but distinct crenulations. Surface marked by ordinary concentric lines of growth, and apparently by faint radiating lines, which corre- spond in position to the inner crenulations of the pallial border. The surface of neither of the only two examples in the collection is well pre- served, but it is evidently nearly smooth and not radiately ribbed, as is usual in this genus. Upon weathered surfaces radiate lining is dis- tinetly seen, but it is probable that it was less distinct upon the natural surface. Height and width of the largest example, each about 47 millimeters. The genus Awinea is regarded as a distinctively marine form, and the discovery of this species in the Laramie Group, especially so near its top as this form was found, was therefore quite unexpected. Upon its discov- ery the idea was first suggested that the specimens had been derived by erosion from strata of the pre-existing Fox Hills Group, but the condi- tions of their preservation and association were found to be such as to leave no doubt that the mollusks which formed them lived in Laramie waters. Their immediate associates are Ostrea glabra var. wyomingensis and Corbicula occidentalis, all being imbedded in the same layer. These two species are there abundant, and the only fresh-water form that was found among them was a single example of Viviparus. This is sufficient evidence that the waters in which they lived was at least in a good degree saline, for the single Viviparus may easily have drifted in among the others, while the latter are too numerous to suppose they had drifted into fresh waters. Besides which, currents of fresh waters go to saline waters, but not the reverse. The inference seems to be necessary, or at least natural, that this Axvincwa survived without generic change in the freshening waters of the Laramie period, while the marine associates of its progenitors failed to survive the changing conditions which wrought an almost complete faunal revolution in those waters. There are many known cases of survival analogous to this, and, even in this same Lara- mie Group, there are two other forms the congeners of which are gen- erally regarded as of exclusively marine habitat or affinities, namely Vu- culana and Odontobasis. That these forms really survived from former marine waters by adaptation to changed conditions, and that their pres- ence where we have found them was not due to occasional incursions of true marine waters, is apparent from the fact that the localities at which they have been found are too distant from the then nearest oceanic waters for the latter to have reached them except by extensive subsidences of land which evidently did not occur. Position and locality.—Only two examples of this shell have been found, one by myself, and the other by Mr. W. H. Holmes, in whose honor the Specific name is given. They were both obtained at Point of Rocks Station, Bitter Creek Valley, Wyoming, from Laramie strata, near the top of the group. Genus NUCULANA Link. NUCULANA INCLARA White. Plate 25, fig. 7 a. Nuculana inclara White, 1878, Bull. U. 8. Geol Sur. Terr., vol. iv, p. 708. _ Shell small, elongate subovate in marginal outline, gradually narrow- ing behind the beaks; valves only moderately convex even upon the WHITE.] LARAMIE FOSSILS. 61 anterior and umbonal portions, and without distinct umbonal ridges ; beaks not prominent, situated about one-third the full length of the shell from the front; basal margin broadly semi- elliptical ; anterior margin regularly rounded from the cardinal Inargin ;to the base ; pos- tero-basal margin sloping upward to the posterior margin, which is sharply rounded to the cardinal margin; the latter margin slightly arched, or the anterior and posterior portions of it forming a very slight angie with each other; denticles minute, numerous, twelve to fifteen or more in front of the beak, and a somewhat greater number behind it. The very few examples of this species which have been discovered being in the form of natural casts in indurated shale, the true character of the surface is not accurately known, but it appears to have been marked only by ordinary concentric lines of growth. Character of the pallial and muscular impressions unknown. Length, 11 millimeters ; height from base to beaks, 5 millimeters. No examples larger than this were discovered, but it is probable that it is larger at full adult size. The occurrence of this genus within two hundred feet of the base of the group would not excite surprise, if it were not well known that the fresh and brackish water species which prevail in the Laramie Group are associated with it. The presence of the latter forms, however, in the same layers indicate that true marine conditions had ceased at the very beginning of the Laramie period. Position and locality —aramie Group ; associated with Corbula wndi- fera, Anomia micronema, Melania wyoningensis, &c.; Danforth Hills, near White River Indian Agency, Northwestern Colorado. Genus ANODONTA Cuvier. ANODONTA PROPATORIS White. Plate 24, figs. 2, a, b,e, and d. Anodonta propatoris White, 1877, Buli. U. S. Geol. Sur. Terr., vol. iii, p. 601. Shell elongate subelliptical in marginal astiie valves moderately and somewhat uniformly convex; beaks small, slightly elevated above the cardinal border; hinge-line lon gand straight ; basal border broadly convex ; front regularly rounded from the base up to the antero-dorsal border, which latter border is more abruptly rounded to the hinge-line ; postero-dorsai border oblique and slightly convex ; postero ventral border somewhat abruptly rounded from the postero-dorsal to the basal border ; cardinal margin slightly thickened but entirely plain and characteristic of the genus Anodonta. Surface plain, or marked only by the usual lines and undulations of growth. Length of the largest example in the collection, 62 millimeters: height of the same from base to beaks, 36 millimeters; length of a partly grown example, 37 millimeters; height of the same, 20 millimeters. This species is not only a true Anodonta, Dut in all its characteristics and its general aspect it very closely resembles several living American species of that genus. None of the examples are perfectly preserved, but the characteristics of the species are nevertheless well shown, and should perfect examples ever be discovered, it will probably be difficult to say how it differs from some one of the many closely similar living forms. It is not to be denied that in this case a separate specilic iden- 62 GEOLOGICAL SURVEY OF THE TERRITORIES. tity is assumed from its known antiquity, rather than proved by an as- semblage of specific characteristics. At the time of its discovery this was the only species of Anodonta that had ever been found in any strataof Western North America of either Mes- ozoic or Cenozoic age; and, with the exception of the next described species, it is the only known Anodonta yet known from any of the West- ern strata of the ages mentioned. Position and locality —tLaramie strata of the Judith River series, Dog Creek, and also upon the north side of the Missouri River, near Birch Creek, Montana, where it was collected by Prof. E. D. Cope in the sum- mer of 1876. ; ANODONTA PARALLELA White. Plate 24, fig. 3a. Anodonta parallela White, 1878, Bull. U. S. Geol. Sur. Terr., vol. iv, p. 709. Shell transversely much elongate, oblong or semi-elliptical in mar- ginal outline; valves gently convex, apparently a little more so near the front than elsewhere; beaks situated about two-sevenths of the whole length of the shell from the front, depressed, the elevation of the whole umbonal region being very slight or hardly perceptible ; hinge line long; the whole dorsal border nearly straight; both the anterior and pos- terior borders regularly rounded, that of the posterior end being a little more abruptly rounded than the front; base nearly straight, or perhaps very Slightly emarginate along or a little in front of the mid-length; test thin; surface smooth, or marked only by the usual lines of growth, and one or two faint linear ridges running from the beaks to the postero- dorsal margin. Length, 62 millimeters; breadth, 20 millimeters. The extraordinary length of this shell compared with its width is an unusual feature in Anodonta, but all its other characteristics, so far as they can be observed on the only examples that have yet been discov- ered, indicate it to be a true Anodonta, the correctness of which reference is also suggested by the fact that all its immediate associates are fresh- water forms. Only two examples have been discovered, both of which are imperfect, figure 3 a on plate 18 being a restoration drawn from both examples. Position and locality—Laramie Group, valley of Crow Creek, North- ern Colorado, about ten miles above the confluence of that creek with Platte River. Genus UNIO Retzius. UNIO ALDRICHI White. Plate 29, figs. 2 a and b. Unio aldrichi White, 1878, Bull. U. S. Geol. Sur. Terr., vol. iv, p. 710. Shell of medium size, transversely elongate, approximately oblong in marginal outline, height not diminishing posteriorily; valves moderately gibbous, especially along the umbonal slopes or ridges, and also forward of these; test moderately thick, becoming more so in old shells; beaks situated nearly one-third the full length of the shell from the front, in- curved, broad but not very prominent, although the flattened umbo is raised above the hinge line; umbonal ridge prominent, subangular ; WHITE, ] LARAMIE FOSSILS. 63 postero-dorsal portion of the shell behind the umbonal ridges compressed, and in young examples it is there subalate; front portion of the shell moderately gibbous, and between the front and the umbonal ridges the sides are flattened; anterior margin regularly but somewhat narrowly rounded down to the basal margin, which latter margin is straightened along its middle portion; postero-basal margin somewhat narrowly rounded, and extended upward and backward to the postero-dorsal mar- gin; the latter margin sometimes truncated obliquely downward and backward and sometimes so rounded as to give an approximately square truncation to the posterior end of the shell; hinge line long and straight. Surface marked only by the ordinary lines of growth except all that portion which lies behind and above the umbonal ridges. This portion of the surface is marked by numerous sharply raised irregular lines or narrow ridges, with the intervening spaces wider than the ridges thein- selves, which, beginning almost imperceptibly just behind the umbonal ridge, extend backward with a greater or less upward curve to the dor- sal and posterior borders. They usually constitute a conspicuous surface feature of the shell, but in the case of old examples they appear to have become obsolete. Their character is similar to that of markings upon corresponding parts of U. senectus, and U. primevus, especially the latter. Length of the largest discovered example, 82 millimeters; height of the same at mid-length, 48 millimeters; thickness, about 32 millimeters. The specific name is given in honor of Mr. Charles Aldrich, formerly a member of this survey. Position and locality—Upper portion of the Laramie Group, Black Buttes Station, Union Pacific Railroad, Wyoming, where it is associated with a majority of the following-described species of Unio, and also with several other molluscan species. UNIO GONIAMBONATUS White. Plate 29, figs. 1 a and b. Unio goniambonatus White, 1878, Bull. U. 8. Geol. Sur. Terr., vol. iv, p. 709. Shell of medium size, transversely elongate, subtrihedral in marginal outline, being rapidly narrowed posteriorly from the anterior portion ; valves moderately gibbous, their greatest convexity being in front of the mid-length and above the mid-height; test moderately thick; um- bones prominent, but not much raised above the cardinal margin; beaks situated near the anterior end, depressed, a little flattened; um- bonal ridge distinct, angular, and so prominent as to produce a flattened or even slightly concave space between it and the cardinal margin, giv- ing the whole back of the shell a broadly flattened aspect; front margin regularly rounded from beneath the beaks to the basal margin, which latter margin is nearly straight in some examples, but in others broadly convex; postero-basal margin narrowly, and sometimes irregularly, rounded to the postero-dorsal margin; the latter margin forming a gentle slope downward and backward from the posterior end of the hinge; cardinal margin nearly straight, and occupying about two-thirds the whole length of the shell. Surface marked only by the ordinary lines and imbrications of growth, but usually the angular umbonal ridges are each cut across by three or four short, distinct folds or ridges, and their intervening furrows, extend- ing obliquely inward and backward, being scarcely perceptible in front of the umbonal ridge, and becoming obsolete before reaching the pos- tero-dorsal margin, or at least producing only slight undulations in it. Length, 58 millimeters; height from base to umbones, 34 millimeters; thickness, both valves together, 28 millimeters. 64. GEOLOGICAL SURVEY OF THE. TERRITORIES. The elongate, subtrihedral outline, prominent, angular, and wrinkled umbonal ridges, and bread, flattened dorsum of this species, are features which separate it distinctly from all other known forms, whether tossil or recent, and, together with the last and the six or eight next described species, which are associated with it, shows an extent and diversity of differentiation among these earlier species of Unionidee that is hardly surpassed among living forms of that family even in North American fresh waters. Position and locality.—Upper part of the Laramie Group, Black Buttes Station, Union Pacific Railroad, Wyoming. UNIO BRACHYOPISTHUS White. Plate 22, figs. 2 a and b. : Unio brachyopisthus White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 126. Shell small or of medium size, somewhat gibbous, subcireular in mar- ginal outline, the length and height being about equal; umbones broad, not prominent; beaks depressed, situated near the middie of the dor- sum; postero-dorsal portion of the shell broadly flattened, or so de- pressed that rounded or subangular umbonal ridges are formed, bound- ing the flattened or depressed posterior; cardinal margin short, and that portion of it behind the beaks is usually so depressed that the hinge ligament is hidden from sight by side view of the shell. Surface marked only by the ordinary concentric lines and laminations of growth. Length and height of the largest example discovered, each 44 millime- ters; but the example figured on plate 16 is much smaller. This species may be readily distinguished by its subcircular outline and its very short, abruptly-sloping, and rounded posterior. The pos- terior portion of the young shell of this species is not proportionally so short as that of the adult, because the additions by growth are made more rapidly upon the basal border than upon that of the postero-basal region; aS is commonly the case with shells of this genus. Position and locality—Upper strata of the Laramie Group, Black Buttes Station, Union Pacific Railroad, Wyoming, where it is associated with the preceding and most of the following-deseribed species: UNIO COUESI White. z Plate 27, fig. 1 a. Unio petrinus White (not Gould, 1855), 1876, Powell’s Rep. Geol. Uinta Mts., p.-125. Unio couesi White 1877, Bull. U. S. Geol. Sur. Terr., vol. iii, p. 605. Shell very large, transversely elongate, moderately thick; test mas- sive in fully adult shells; basal and dorsal margins subparallel, the latter broadly or slightly convex and the former more nearly straight or faintly emarginate a little behind the mid-length; front abruptly rounded; pos- tero-dorsal and postero-basal margins both somewhat abruptly rounded to the posterior margin, giving in most cases a subtruncated appearance to the posterior end of the shell; beaks depressed, scarcely distinguish- able as such, situated in advance of the mid-length of the shell; umbones broad, not prominent; hinge massive, both cardinal and lateral teeth being strong and well developed. Surface marked only by the usual concentric lines and imbrications of growth, which become coarse and prominent in old shells. The outer prismatic layer is well preserved on some of the examples, and the same has been detected upon all the other Ware. ] LARAMIE FOSSILS. 65 species of Unio that have been found associated with it. Also, like all the species of Unio from the Mesozoic and Cenozoic strata of Western North America which I have examined, the umbones, even in the case of old shells, appear to have suffered no erosion, such as is common in the case of living Uniones of North American rivers. Length of the largest example discovered, 150 millimeters; height of the same, 75 millimeters. The length of young shells, compared with their height, is proportionally greater. This species was originally named U. petrinus (loc. cit.), but the name was subsequently changed to U. couesi, because the former name had been preoccupied by Gould for a living species of Unio. It may be distinguished from all other species that are in any way likely to be confounded with it, by its very great size, elongate form, and subparallel dorsal and basal margins. Position and locality—Upper portion of the Laramie Group, Black Buttes Station, Union Pacific Railroad, Wyoming, where it is associated with the majority of the species of Unio described in this article; besides several species of Gasteropods. UNIO PROPHETICUS White. Plate 22, fig. 5 a. Unio propheticus White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 125. Shell not above medium size, obliquely subovate in marginal outline, moderately thick, the greatest thickness being a little below the um- bones; test moderately thick; umbones prominent; beaks reaching to or a little beyond the front of the shell, curved inward and a little for- ward; front nearly perpendicular; front margin slightly concave above, but abruptly rounded to the basal margin below; basal margin straight- ened or sometimes a little emarginate; posterior extremity abruptly rounded; dorsal margin broadly rounded, and forming, with the postero- dorsal margin, a continuous curve from the beaks to the posterior ex- tremity ; the portion of each valve which bears the hinge is so inflexed as to produce a dorsal concavity that hides from sight the hinge ligament when the shell is seen by side view. Surface marked by the ordinary lines of growth, and by numerous fine radiating striz, which appear more distinctly in the substance of partly exfoliated portions of the test. Length, 50 millimeters; height from base to umbones, 37 millimeters. This fossil species is of the type of the living VU. clavus Lamarck, which it much resembles in general aspect. It also resmebles, in some of its features, the next described species, U. proavitus, with which it is asso- ciated ; but it is so different from any other knowh fossil Unio, from American strata that it cannot be mistaken for any of them. Position and locality—Laramie strata, near the top of the group, Black Buttes Station, Union Pacific Railroad, Wyoming, where it is associated with the preceding, and also with the majority of the species of Unio which are described in this article. UNIO PROAVITUS White. Plate 22, figs. 3a, b, c, and d. Unio proavitus White, 1877, U. 8. Geol. Sur. Terr., vol. iii, p. 603. Shell of medium size, moderately ventricose, irregularly oblong or subtetrahedral in marginal outline; front moderately broad and trans- 5H 66 GEOLOGICAL SURVEY OF THE TERRITORIES. versely somewhat flattened below the beaks; test of ordinary thickness; basal and dorsal margins subparallel, the latter being broadly convex, and the former more nearly straight, or sometimes a little emarginate; front margin regularly rounded from beneath the beaks to the basal margin ; posterior margin nearly straight or slightly convex, truncating the shell obliquely upward and backward, abruptly rounded to the basal margin and somewhat sharply rounded to the dorsal margin; beaks moderately strong, not elevated, but incurved and projecting beyond the front of the shell; the antero-dorsal and umbonal portions of each valve are sufiiciently elevated to hide the cardinal ligament when the shell is seen by side view, but the postero-dorsal portion of each valve slopes away directly from the dorsal margin. Two obtuse ridges or ele- vations radiate from the beak of each valve to the margin. One of these, the umbonal ridge proper, ends at the junction of the posterior and basal margins, and the other at the junction of the posterior and dorsal margins. Between the latter ridge and the dorsal margin the space is narrow; between the two ridges the space is wider and distinctly flattened, and forward of the umbonal ridgethereisan umbonal flattening, or very broad and very shallow unbonal sinus, which, extending from the umbo to the basal margin, causes the slight emargination there that has been referred to. Cardinal teeth moderately strong; lateral teeth well developed. Surface marked by the ordinary lines and undulations of growth, and faint radiating lines are also usually observable, especially where the prismatic layer has been exfoliated. Length from front to postero-dorsal prominence, 52 millimeters ; height from basal margin to dorsum, 35 millimeters; greatest thickness, both valves together, 31 millimeters. This species is related to U. propheticus White, as alreaily noticed in connection with the description of that species, but the differences are well characterized in the description of each, and they are also well shown by the figures on plate 22. The extreme anterior position of the beaks in these two species is a common characteristic among the fossil Uniones of Western North America, from the Jurassic to the Hocene Strata inclusive. This feature is not unknown among living North American forms of Unio, but it is proportionally less common among them than among the fossil forms. Position and locality—Upper strata of the Laramie Group, Black Buttes Station, Union Pacific Railroad, Wyoming, where itis associated with all the previously described species of this article, and also with a part of the following. UNIO ENDLICHI White. Plate 26, figs. 1 a and Bb. Unio endlicht White, 1877, Bull. U. S. Geol. Sur. Terr., vol. iii, p. 604. Shell large, obliquely elongate, subovate in marginal outline, moder- ately thick, very short in front of the beaks and elongate and rapidly narrowed behind them; test strong, and massive in old shells; basal margin having a slight general convexity, but it is straightened, and sometimes a little emarginate at or a little behind the mid-length, regu- larly and continuously rounded to the front, and abruptly rounded to the postero-basal margin; dorsal margin proper rather short, broadly rounded from front to rear; postero-dorsal margin forming a long, gently _ convex downward slope to the posterior margin, which latter margin is very narrowly rounded ; beaks much depressed, scarcely distinguishable WHItE.] LARAMIE FOSSILS. 67 as such, and the whole umbonal region only slightly prominent; hinge well developed; cardinal teeth strong; lateral teeth large and very long. Surface marked by the ordinary concentric lines and imbrica- tions of growth, which are coarse and rough on old shells. Length of the largest example yet discovered, 130 millimeters; great- est height of the same, 70 millimeters. These proportions, and conse- quently the marginal outline, varied somewhat with their growth, young examples being longer in proportion to their height. The fragments in the collection also show that the outline of adult forms was subject to considerable variation in proportional length. This species resembles U. couesi, with which it is associated, in its large size, massive test, and simple surface ; but it differs materially in outline, being much narrower posteriorly, and having its beak much nearer to the front of the shell than it is in that species. It bears some resemblance also to some of the varietal forms of U. danw, Meek & Hay- den, but it is constantly a more massive shell than that species; is always proportionally wider or higher at its highest part, which is near the front; and it also has its beaks placed farther forward, the front of U. endlich projecting only very little beyond the beaks. Position and locality—Upper portion of the Laramie Group, Black Buttes Station, Union Pacific Railroad, Wyoming, where it is associated with the greater part of the species of Unio described in this article, as well as several species of Gasteropods. UNIO HOLMESIANUS White. Plate 22, figs. 4 a, b, c, d, and e. Unio holmesianus White, 1877, Bull. U. 8. Geol. Sur. Terr., vol. iii, p. 604. Shell small, or of medium size, compact, moderately gibbous, sub- trihedral in marginal outline, of ordinary length anteriorly for a short Shell, but very short posteriorly; the postero-dorsal portion forming only a small narrow prominence upon the broad, abruptly truncated posterior ; valves, in front of the umbonal sinus, regularly convex; umbonal sinus well defined but somewhat narrow, its posterior side a little higher or more distinetly defined than the anterior side, the sinus terminating at the base of the shell a little behind the middle; umbonal ridge promi- nent, forming a roughly rounded angle between the side of the valve and the posterior or postero-dorsal portion; cardinal margin very short; antero-dorsal margin sloping gently downward to the front of the shell, front and antero basal margins forming a regular and continuous curve, which extends to that portion of the basal margin where the umbonal sinus ends, where the base is a little emarginate; postero-basal margin a little roughened and abruptly rounded to the almost perpendicular or slightly oblique posterior margin; umbones somewhat prominent; beaks small, incurved; cardinal ligament moderately large. Until the shell had reached about one-third its full adult diameter the whole sur- face was marked by somewhat close-set rhombic papilla, which are ar- ranged in more or less distinct oblique lines, and which remain as the ornamentation of the upper and umbonal portions of the adult shell. All the surface below the portion thus marked by the papille and in front of the umbonal sinus is plain, or marked only by the ordinary dis- tinct lines of growth. All the surface behind the umbonal sinus is marked by small, irregular, somewhat corrugated ridges, which are stronger upon the umbonal ridge than elsewhere, and from the median line of which they sometimes diverge downwards, and towards both the 68 GEOLOGICAL SURVEY OF THE TERRITORIES. umbonal sinus and the posterior margin; but sometimes they radiate irregularly to the posterior and postero-basal margins. Length of an adult example, 45 millimeters ; height from base to beaks, “42 miilimeters. This species presents a greater degree of differentiation from what may be regarded as the typical form of Unio than any other known fos- sil species, and fully as great as that of any species now living, even in North America fluvatile waters. It is of the same type as the living species U. rugosus Barnes, and in many respects it resembles that shell. Like many other fossil Uniones of the western portion of North America, it has representatives among living types that are now peculiar to this continent. Position and locality—Upper portion of the Laramie Group, Black Buttes Station, Union Pacific Railroad, Wyoming, where it is associated with all the preceding species of Unio herein described, and also with other fresh-water species, including several Gasteropods. UNIO DANZ Meek & Hayden ? Plate 27, Figs. 2 a and b. Unio dane was originally discovered in strata of the Judith River series of the Upper Missouri River region by Dr. Hayden. It is figured and described by Meek in vol. ix, U. S. Geol. Sur. Terr. (4to ser.), p. 518, plate 41, figs. 1 a@and b. From the upper strata of the Laramie Group at Black Buttes Station, and associated with all the species of Unio that are described on the foregoing pages, some well preserved examples have been obtained which seem to belong to the species in question. Two examples are figured on plate 27, showing, respectively, the exterior and interior surfaces. All these examples show that the surface, even in the case of fully adult shells, was more than usually smooth; in which respect, as well as in others, it resembled the living species U. rectus Lamarck. UNIO CRYPTORHYNCHUS White. Plate 24, figs. la and b. Unio crypterhynchus White, 1877, Bull. U. 8. Geol. Sur. Terr., vol. iii, p. 600. Shell of medium size, ventricose, subelliptical in marginal outline; height a little greater forward of the mid-length than elsewhere; test moderately thick; dorsal margin nearly straight or slightly convex; basal margin broadly convex; posterior margin regularly rounded; front margin also regularly rounded from beneath the beaks to the ventral margin; beaks rather large, distinctly defined from the body of the shell, not elevated, but projected forward and turned strongly inward, placed near the anterior end of the shell, but not reaching quite so far forward as the anterior border, between which and the beak there isa distinct sulcation; cardinal teeth strong; each valve having behind the cardinal teeth a moderately deep crypt or cavity of the beak; lateral teeth well developed, but thin and sharp. Surface marked only by the ordinary lines and lamellations of growth. Length, 70 millimeters; greatest height from base to umbo, 45 milli- meters. This species bears some resemblance to U. proavitus White, which has been described on a foregoing page. That species was found in the Wuute. | LARAMIE FOSSILS. 69 upper strata of the Laramie Group at Black Buttes Station, Wyoming, where also some imperfect examples of a species apparently identical with U. cryptorhynchus have been found. This species differs from U. proavitus, however, in wanting the umbonal and postero-dorsal ridges and oblique posterior truncation of the last-named species, and also in having the front margin projecting a little beyond the beaks, instead of having the beaks projecting a little beyond the front margin as they do in U. proavitus. Position and locality.—Prof. E. D. Cope discovered this species in 1876 in strata of the Judith River series of the Laramie Group, on Dog Creek, a tributary of the Upper Missouri River. As already stated, it appar- ently exists also in the upper strata of the Laramie Group at Black Buttes Station, Union Pacific Railroad, Wyoming. None of the speci- mens found at the latter locality are, however, sufficiently perfect for satisfactory determination. UNIO SENECTUS White. Plate 28, figs. 1 a, b, and e. Unio senectus White, 1877, Bull. U. S. Geol. Sur. Terr., vol. iii, p. 600. Shell elongate-subelliptical in marginal outline; convexity of the valves comparatively slight, and nearly uniform over the whole surface; test thin; both basal and dorsal margins broadly convex, or the former sometimes a little straightened; front regularly rounded; posterior margin also rounded, but sometimes more abruptly so than the front ; beaks scarcely definable as such from the body of the shell, situated at about one-fifth the length of the shell from the front; hinge well de- veloped ; cardinal teeth prominent, but somewhat thin; lateral teeth long and weil formed, having between their anterior end and the cardi- nal teeth a considerable plain space. Above and behind a line drawn from the beaks to the postero-basal margin, that is, along the line of the umbonal ridge, when one is present, the surface is marked by very humerous small creuulated undulations, which increase in number both by implantation and. bifurcation with the increasing size of the shell; their general direction being backward, but along the dorsal portion of the valve they are flexed upward and end upon the dorsal margin. Below and in front of this line the surface is plain, being marked only by the ordinary lines of growth, except some fine radiating lines which appear in the substance of the shell when it has been exfoliated. Length, 80 millimeters; height, 40 millimeters. In its general form and surface characters, this species somewhat resembles the living Margaritana rugosa Barnes, but the undulations upon the postero-dorsal surface are much smaller, more numerous, and they occupy a proportionally broader space upon the surface of the shell than they do in that species; besides which the species here described is a true Unio, and not a Margaritana. Position and locality.—Strata of the Judith River series of the Laramie Group, valley of Dog Creek, a tributary of the Upper Missouri River, Montana, where it was discovered by Prof. E. D. Cope in 1876. Mr. J. A. Allen also brought in examples of this species from the valley of Yellowstone River, Montana. 70 GEOLOGICAL SURVEY OF THE TERRITORIES. UNIO PRIMAVUS White. - Plate 29, figs. 3 a and b. Unio primevus White, 1877, Bull. U. 8S. Geol. Sur. Terr., vol. iii,*p. 599. Shell of medium size, broadly subovate in marginal outline when adult, but proportionally narrower when young; valves moderately convex, each having a faint umbonal sinus or radiating flattened space, which ends at the basal margin a little behind the mid-length of the shell; this sinus or flattened space is bordered posteriorly by a broad undefined, umbonal ridge, or slight radiating prominence which ends at the postero-basal border; beaks situated nearly equidistant from the anterior and posterior ends, or a little nearer to the anterior, prominent by reason of the sloping away from it of both the antero and postero dorsal borders as well as the sides; from the beaks to the postero-basal portion of the shell the margin is broadly convex; postero-basal margin abruptly rounded to the base, the latter margin being gently convex, or sometimes a little straightened where it is met by the umbonal sinus or flattened space; front regularly rounded; both cardinal and lateral teeth well developed; the cardinal tooth of the left valve passing into a pit in the right valve which is situated directly under the beak. The pos- terior end of the lateral portion of the hinge has a peculiar modification of the usual method of articulation in Unio, as shown by fig. 3), plate 29. It also ends by a thickening of the substance of the hinge and a round- ing of its end, instead of having the lateral teeth ending sharply as is usual in shells of the genus Unio. Surface marked by the ordinary lines and undulations of growth, and the postero-dorsal portion is also marked by irregular raised linear ridges that have a somewhat cor- rugated appearance, their direction being from the beak towards the posterior and postero-basal borders. Besides these markings exfoliated portions of the test show fine radiating lines. This shell may be readily distinguished by its broadly subovate out- line and the peculiar irregular raised lines on the postero-dorsal surface. The peculiar character of the end of the lateral portion of the hinge which is seen in this shell is also to be observed in U. stewardi White, from the Jurassic strata of Northern Utah, but the hinges of the fossil Uniones that have hitherto been found in the Mesozoic and Cenozoic rocks of Western North America do not otherwise show any differences from those which prevail among the living Uniones of North American rivers. Length of an adult example, 65 millimeters; height of the same from base to beaks, 49 millimeters. Position and locality—Ferruginous sandstones at the summit of the Judith River series of the Laramie Group; south of Cow Island, Upper Missouri River, Montana, where it was collected by Prof. H. D. Cope in 1876. UNIO PRISCUS Meek & Hayden. This species was discovered by Dr. Hayden in strata of the Judith River series of the Laramie Group, in the valley of Yellowstone River, and it has hitherto been discovered nowhere else. It is described and figured in vol. ix, U. 8. Geol. Sur. Terr. (4to ser.), p. 516, plate 43, figs. 3.a, b, ¢, and d. WHITE. LARAMIE FOSSILS. 71 UNIO SUBSPATULATUS Meek & Hayden. UNIO DEWEYANUS Meek & Hayden. These two species were obtained by Dr. Hayden from the Judith River series of the Laramie Group, at the mouth of Judith River, Mon- tana. They are described, respectively, on pages 518 and 519 of vol. ix, U.S. Geol. Sur. Terr. (4to ser.), and both are figured upon plate 41 of the same volume. UNIO VETUSTUS Meek. UNIO BELLIPLICATUS Meek. Both of these species are described and figured in vol. iv, U. S. Geol. Sur. 40th Parallel (King), the former on p. 164, pl. 16, figs. 5 and 5 a, b, and ¢; and the latter on p. 165, pl. 16, figs. 4 and 4 a. The former is also described and figured in Captain Simpson’s report of the Great Basin of Utah, p. 361, pl. 5, figs. 12 aand b. They are both as- sociated together in the Bear River series of the Laramie Group at sev- eral points in Bear River Valley, both above and below Evanston, Wyo. Dr. Peale has also brought fragments of the former from two or three localities still farther northward. UNIO GONIONOTUS* White. Plate 26, figs. 2 a, b, ¢, d, and e. Unio gonionotus White, 1676, Powell’s Rep. Geol. Uinta Mts., p. 116. Shell elongate subelliptical in marginal outline; flattened and thin when young, but becoming gibbous and even almost cylindrical when fully adult; dorsal margin broadly convex; base straightened in the adult, but broadly convex in the young shell; front regularly rounded ; the rounding of the posterior end somewhat irregular in consequence ot the presence there of the plications which end posteriorly; beaks obso- lete, the umbonal surface of each valve so flattened that they form an acute angle at the dorsum of young shells, but the angle increases in ‘degree with age so that it is very obtuse in the adult shell. Surface of the anterior portion of the shell marked only by the ordinary lines and laminations of growth, but the posterior portion, comprising more than half the length, is marked by a few strong, more or less irregularly radi- ating plications, which begin faintly a little forward of the middle, and increase gradually in strength to the posterior and postero-dorsal mar- gins, the number being increased by a few bifurcations as the shell in creases in size. Curving upward and backward from the uppermost of * the longer plications just mentioned there are several smaller, shorter ones that end at the postero-dorsal margin. Length of the largest example in the collection 63, millimeters; height, 35 millimeters. Young examples have very different proportions and shape, as is shown by figures 2 ¢, d, and e, on plate 26. This species differs conspicuously from any other fossil Unio known to me, although young examples of it bear some resemblance to those of the living species U. multiplicatus ; but adult examples have a very *This species is one of the collection made by Professor Powell at Upper Kanab, Southern Utah, and the only one of that collection which is illustrated in this article. 12 GEOLOGICAL SURVEY OF THE TERRITORIES. different aspect. Although two or three species of Unio from strata of the Laramie Group have the surface partially rugose, this form, with the exception of U. belliplicatus, is the only distinctly plicate one that has yet been found in any American strata. It differs from U. belliplicatus in its general shape and in the position and distribution of the plica- tions, which are most conspicuous on the anterior portion of that shell, while the corresponding portion of U. gonionotus is plain. Position and locality —Laramie strata, Upper Kanab, Southern Utah, where the only known examples of the species were collected by Pro- fessor Powell. Genus SPH/ZRIUM Scopoli. SPHZRIUM PLANUM Meek & Hayden. SPH4ZRIUM RECTICARDINALE M.& H. SPHZRIUM FORMOSUM M. & H. SPH4RIUM SUBELLIPTICUM M. &. H. These four species of Spheriwm were collected from the Laramie strata of the Upper Missouri River region by Dr. Hayden—the two former from the Judith River series, and the two latter from the Fort Union series. They are all described in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), pages 526 and 527, and figured on plate 43 of the same volume. No other examples of Sphcriwm have been discovered in the Laramie Group, if we except a small undescribed form in the coal-bearing series near Evanston, Wyo. Genus CORBICULA Megerle. CORBICULA OBESA White. Plate 23, Figs. 3 a, b, ¢, d, and e. Corbicula obesa White, 1878, Bull. U. 8. Geol. Sur. Terr., vol. iv, p. 712. Shell small, or not above the average size common to this genus, inflated; sides somewhat regularly convex, suboval, or subtrihedral in marginal outline; transverse length somewhat greater than the height; basal margin almost regularly rounded, meeting both the posterior and anterior margins by regular and nearly equal curves; postero-dorsal - portion of the shell, as seen by side view, regularly rounded from the beaks to the posterior margin; antero-cardinal margin short and straight, but the shell has the appearance of being concave in front of the beaks on account of the slight elevation and forward prominence of the latter; postero-dorsal margin very little, if any, depressed below the adjacent portions of the shell; beaks small, pointed, not prominent, di- rected a little forward, and situated only a little in advance of the mid- length; lateral teeth well developed, slender, and apparently not crenu- ° late, but none of the examples in the collection are in a condition to show the natural surface of the teeth clearly; cardinal teeth well de- veloped, but not robust; pallial sinus small. Surface marked only by the usual lines of growth; and these being mostly very fine, the surface has a comparatively smooth, or sometimes even a polished, aspect in well preserved examples. Length of the largest example in the collection, 38 millimeters ; height of the same from base to umbo, 30 millimeters; thickness, both valves together, 25 millimeters. The average adult size is apparently consid- erably less. wuts. ] LARAMIE FOSSILS. 73 The distinctly subglobose form and comparatively smooth surface of this species are distinguishing features, and it differs too greatly from any described form of the germs to ueed detailed comparison with any. While the greater part of the species found in strata of the Laramie Group that are referred to Corbicula vary in different characteristics and degrees from the typical forms of that genus, this one seems to possess the true typical characters. Atleast it is notreferable to either of the subgenera that have been proposed, and which are noticed on following pages. Position and locality—Laramie Group, valleys of Crow and Bijou Creeks, Northern Colorado, at which localities alone it has yet been found, and where it is associated with other species of Corbicula. CORBICULA CARDINIZFORMIS White. Plate 25, figs. 5 a and Db. Corbicula cardinieformis White, 1878, Bull. U. 8. Geol. Sur. Terr., vol. iv, p. 711. Shell somewhat above medium size for a species of this genus, trans- versely subelliptical, moderately gibbous, especially a little forward of and above the middle, but somewhat compressed towards the free mar- gins, especially in the posterior region; front and posterior margins both somewhat narrowly rounded, and the base broadly rounded, forming together nearly a semi-ellipse; cardinal margin broadly rounded, the postero-dorsal margin sloping gently downward from the beaks to the posterior margin; antero-dorsal margin slightly concave just in front of the beaks, where the slight inflexion of the valves also produces a slight concavity in the:shell when both valves are together; umbonal portion of each valve prominent; beaks narrowed, distinctly defined, not much elevated, but pointing strongly forward and incurved. Hinge and in- terior markings unknown. Length from front to rear, 59 millimeters; height from base to beaks, _ 38 millimeters; greatest thickness, both valves together, 28 millimeters. In external torm this species seems to occupy an intermediate position between the usual short or typical forms of Corbicula and that section of the genus which was separated from it by the late Mr. Meek under the subgeneric name of Leptesthes. In this respect it bears considerable resemblance to a form figured on plate 23, figs. 2a and b, which I re- gard as only a variety C. (Z.) fracta Meek. It differs, however, from that form, and from all other species of Leptesthes known to me in the promi- nence and distinct definition of the beaks; the umbonal region being broadly flattened and the beaks depressed and illy defined in all the published species of the subgenus Leptesthes ; which feature seems to be one of its distinguishing characteristics. It was found associated with C. cleburni, to which it bears some resemblance in general form, but it differs too greatly from it to need detailed comparison. Position and locality——Laramie Group, Valley of Crow Creek, 15 miles above the confluence of that creek with Platte River, Northern Colorado CORBICULA CLEBURNI White. Plate 23, figs. l a, b, and ec. Corbicula cleburni White, 1878, Bull. U. S. Geol. Sur. Terr., vol. iv, p. 711. Shell rather large, subcircular or subtrihedral in marginal outline ; height from base to umbo about equal to the extreme transverse length, 74 GEOLOGICAL SURVEY GF THE TERRITORIES. moderately gibbous, the valves having a nearly regular convexity, flat- tened or a little concave along the postero-dorsal portion; moderately concave in front of the beaks, where there is an almost defined lunule ; test thick or even somewhat massive in old shells; dorsal outline forming a somewhat regular convex curve from the beaks to the postero-dorsal portion, the border of which latter portion is abruptly, sometimes almost angularly, rounded to the lower margin; the latter margin forming an approximately true semicircular curve from the posterior to the antero- cardinal margin, but the convexity of this curve is in old shells a little greatest about its middie; antero-cardinal margin straight or slightly concave, meeting the antero-basal margin at an obtuse angle or promi- nent, abrupt curve; beaks prominent, elevated, curving inward and forward, and, when well preserved, ending in a well-defined point; lateral teeth strong, well developed, and finely crenulate; cardinal teeth well developed, the outer posterior one showing, in one example at least, faint crenulations, but otherwise they are of the ordinary character; pal- lial line distinct, somewhat distant from the margin; pallial sinus small, directed str ongly upward. Surface marked only by the ordinary lines and undulations of growth. Height of the largest example in the collection, 42 millimeters ; extr eme transverse length ‘about the same; thickness, both valves together, 32 millimeters. The largest examples are all more or less broken; those figured on plate 25 being of smaller size. This species bears, perhaps, more resemblance to C. cytheriformis Meek & Hayden, than to any other published form; but it may be distin- guished from the typical forms of that species by its more distinctly subtrihedral outline, its greater proportionate height and its concave, almost lunulate front. It bears some resemblance also to C. occidentalis, especially to some examples of the variety of that species which occars in the valleys of Bitter Creek and Yampa Rivers, to be noticed on a fol- lowing page. Position and locality —lLaramie Group, valley of Crow Creek, North- ern Colorado, about 15 miles above the confluence of that creek with - Platte River. CORBICULA CYTHERIFORMIS Meek & Hayden. Plate 21, figs. 4 a, b, c, and d. The type specimens of this species were discovered by Dr. Hayden in the Laramie strata of the Judith River series. It is described and fig- ured by Meek in vol. ix U.S. Geol. Sur. Terr. (4to ser.), p. 520, pl. 40, figs. 5 a,b, ¢,d,ande. It has been recognized also in the Bitter Creek series, the specimens which are illustrated on plate 21 having been obtained from a locality about two miles west of Point of Rocks Station, Union Pacific Railroad, Wyoming. CORBICULA NEBRASCENSIS Meek & Hayden. Dr. Hayden obtained this form also from the Laramie strata of the Upper Missouri River region; and it has not yet been recognized at any other locality. It is “described and figured by Meek in vol. De 10% S. Geol. Sur. Terr. (4to ser.), p. 522, plate 43, figs. 2 a and b. WHITE. | LARAMIE FOSSILS. 75 CORBICULA OCCIDENTALIS Meek & Hayden. Plate 21, Figs. 3a, b, and ec. Corbicula ogeldansalis Meek & Hayden, 1856, Proc. Acad. Nat. Sci. Philad., vol viii, iG: Berticula ( penne) bannistert Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, p. 6 The collections of Dr. Hayden from the Laramie strata of the Judith River series contain the type specimens of this species, which are de- scribed and figured by Meek in vol. ix U.S. Geol. Sur. Terr. (4to ser.), p. 521, Pl. 40, Figs. 6a, b, and c. The illustrations on plate 21, figs. 3a, b, and ¢c, accompanying this article, are drawn from examples that were obtained in the valleys of Bitter Creek and Yampa River, and identified with this species. Figures 3b and 3c are drawn from the type specimen of C. bannistert Meek, which is regarded as synonymous with C. occi- dentalis, because among the numerous examples of the variety of C. oc- cidentalis which were obtained at and near the locality which furnished the type of C. bannistert are many which show a direct gradation to that type from forms which cannot be separated from C. occidentalis. Among the collections brought by Professor Powell from Upper Kanab, Southern Utah, is a single example which I am unable to distinguish from the forms that in the Bitter Creek series I refer to C. occidentalis. - Subgenus LEPTESTHES* Meek. CORBICULA (LEPTESTHES) FRACTA Meek. Plate 23, figs. 2a, b, c, d, and e; and plate 21, fig. 5a. Corbicula? fracta Meek, 1871, An. Rep. U.S. Geol. Sur. Terr. for 1870, p..314. Corbicula? aes var. crassiuscula Meek, 1873, An. Rep. U. 8. Geol. Sur. Terr. for 1872, D. The following is Mr. Meek’s original description of the species: “Shell attaining a rather large size, longitudinally ovate, wider (higher) anteriorly, compressed, very thin and fragile; anterior margin rounded; pallial margin semi-ovate in outline; posterior margin nar- rower than the other and subtruncate ; dorsal outline sloping gradually, with slight convexity behind the beaks, and more abruptly in front; beaks rather depressed, oblique, and placed about one-third the length of the valves from the anterior extremity; surface only showing very obscure lines and somewhat stronger ridges of growth. ““ Length, 2.24 inches; height at the beaks, 1.48 inches; convexity, apparently about 0.40 inch. «Specimens of this species are all more or less flattened by accidental compression, but show the outline and surface characters perfectly, even remains of their epidermis. With considerable difficulty 1 have suc- ceeded in clearing away the matrix so far as to see that the hinge-mar- gin is comparatively streng for so thin a shell. It shows apparently three diverging cardinal teeth in each valve, and a linear anterior lateral tooth extending parallel to anterior margin; while the posterior lateral teeth are somewhat remote from the cardinal, and rather elon- gated. On these posterior lateral teeth I have seen transverse strike, which, doubtless, also exist on the anterior lateral, though I have not seen a specimen in a condition to show them. Internal casts show the *For a diagnosis of this subgenus see vol. ix U. S. Geol. Sur. Terr. (4to ser.) p. 161; and also remarks accompanying this description. 76 GEOLOGICAL SURVEY OF THE TERRITORIES. anterior muscular impression to be ovate, and the posterior, broader, or more nearly circular, while the pallial line shows a shallow, rounded sinus, forming less than a semi-circle. ** Locality and position.—Hallville coal mines, just above a bed of coal, in a black, argillaceous, rather hard rock, that may be shaly at some other places.” Figure 2 a on plate 23 represents one of Mr. Meek’s types, from which the foregoing description was drawn.* At the time he published that description the specimens with a much thicker test were not discovered. The latter specimens occur in a different condition of preservation, but in equivalent strata, near the top of the Laramie Group, at Black Buttes Station, only four miles from Hallville, on the Union Pacific Railroad, Wyoming. The species proves to be a much more variable one in form, and the natural thickness of the test much greater, than was anticipated by Mr. Meek; and there are such good reasons for placing all the Hall- ville and Black Buttes forms under one specific name that I do not adopt his suggestion of a separate name for any of the forms of this type which are found at Black Buttes. Some of the latter forms are figured on plates 23 and 21; which figures show a good degree of varia- tion, but not the full extent which prevails in the species. — The following are Mr. Meek’s remarks on the Black Buttes forms which he discusses under the name Corbicula? fracta var. crassiuscula, two years after his first description was published ; together with his origi- nal remarks on the characteristics of the subgenus Leptesthes, as given in the annual report of this survey for 1872, p. 512. They are given at length because it is desirable to have the full discussion of this sub- genus presented in connection with descriptions and illustrations of all its known species. “This shell agrees so very closely in form and size, as well as in its hinge and pallial and muscular impressions, surface characters, &c., with the species I have described from the shale over one of the Hallville beds [of coal] under the name Corbicula fracta that it hardly seems proper to separate it specifically. Yet in the thickness of the substance of these Shells from the two localities and horizons, there is a very marked dif- ference, those from Hallville being extremely thin, even in the largest specimens, the thickness not measuring more than from 0.02 to 0.03 inch, while in examples of ‘corresponding size of those here under con- sideration it measures from 0.10 to 0.12 inch in thickness. The latter also seem to be more convex, but the Hallville specimens, being gener- | ally more or less flattened between the lamin of the shale, it is diffi- cult to know exactly how far this want of convexity may be due to ac- cidental pressure. ‘“‘T am aware that shells found in argillaceous shales are usually thin- ner than examples of the same species from more calcareous deposits ; but I have never seen a difference of this kind so strongly marked in specimens certainly known to belong to the same species. This thicker shell is therefore placed here provisionally as a variety of C. fracta, under the name crassiuscula, which it ean retain if further comparisons should show it to be specifically distinct. — “Yn describing the species C. fracta, I noticed several points of dif- ference between it and the characteristic forms of Corbicula and Cyrena, and suggested for the group of which it may be regarded as the type, the subgeneric name Leptesthes. The peculiarities mentioned were the * The flexed outline of the posterior border is regarded as accidental to that speci- men only, and not a specific character. wars] LARAMIE FOSSILS. (7 extreme thinness of the shell and its very elongated depressed form. The specimens here under consideration show that the thinness of the shell is not a constant character, though they at the same time show that this type presents other more important differences, of which I had seen indications before, but which I did not mention especially because the specimens then seen were not sufficiently well preserved to permit these characters to be clearly defined. They are differences in the hinge. For instance, although the primary teeth do not differ materially from those of Corbicula and Cyrena, the anterior lateral tooth differs from that of Cyrena in being linear and elongated parallel to the hinge-mar- gin, as well as slightly striated, thus agreeing with the corresponding tooth of Corbicula. Its posterior lateral tooth, however, on the other hand, is more nearly as in Cyrena, being shorter than in Corbicula, and placed very remote from the cardinal teeth, while the intervening car- dinal margins are wide, flat, and, when the valves are united, close fit- ting. Yet this tooth is also striated, as in Corbicula, though less dis- tinetly. Again, the ligament is also decidedly longer than in Corbicula, or than is usual in Cyrena, and also less prominent, there being appar- ently no elevated fulcrum for its attachment. The pallial line shows a shallow subsemicireular sinus. “¢‘T¢ will thus be seen that these shells combine some of the characters of both Cyrena and Corbicula, without agreeing exactly with either. It is well known to paleontologists, however, who have studied fossil shells of these groups, that there are many species that show intermediate characters between these genera, so that some eminent authorities do not admit the genus Corbicula, but place the whole under Cyrena. Should this view prevail, the forms here under consideration might be so dis- posed of. Still, even in that case it would seem desirable and conven- ient to separate them subgenerically by writing the name Cyrena (Lep- testhes) fracta. If the two groups, Cyrena and Corbicula, however, are to be regarded as distinct genera, there would be nearly or quite as good reasons for regarding Leptesthes as a genus.” In some remarks upon C. (Z.) planumbona in the Bulletin of this sur- vey, 2 series, No. 1, p. 45, Mr. Meek further notices the fact that the pedal muscular scar in this subgenus is detached from the anterior ad- ductor scar, and not blended with the latter. This characteristic is shown in figure 4 e, on plate 23, accompanying this article. For other characteristics of Leptesthes, not mentioned by Mr. Meek, see remarks on a following page, following the description of C. (Z.) macropistha. CORBICULA (LEPTESTHES) PLANUMBONA Meek. Plate 21, figs. 2 a, b, c, and d. Corbicula? (Leptesthes) planumbona Meek, 1875, Bull. U. 8. Geol. Sur. Terr., 2d ser., No. 1, p. 43. This species, so far as it is yet known, is confined to the Laramie strata east of the Rocky Mountains in Colorado, where, however, it appears to be comparatively abundant and to have a considerable geographical range. The type specimens from which Mr. Meek drew the following description were all imperfect, and the illustrations on plate 21 are therefore drawn from some fine examples obtained by my- self in the valley of Crow Creek, Colorado: “Shell attaining a moderately large size, rather thick and strong, especially about the hinge of large specimens, generally of a short, trans- versely oval or subelliptic form but rather variable in outline, moder- 78 GEOLOGICAL SURVEY OF THE TERRITORIES. ately and evenly gibbous, the greatest convexity being in the central region; anterior margin prominently and rather narrowly rounded ; posterior vertically subtruncated; base forming a more or less nearly — semi-elliptic or semi-ovate curve; dorsal outline sloping from the beaks, the anterior slope being more abrupt and concave in outline, while the posterior is generally convex; umbones subcentral, moderately promi- nent or somewhat depressed, usually eroded, and more or less flattened near the apices which are not strongly incurved, distinctly pointed, or raised much above the hinge margin; lunular region in the specimens with more gibbous umbones, somewhat excavated, but not distinctly impressed, or with defined margins; ligament narrow and not very prominent jin some well-preserved examples it is quite ‘:prominent] ; anterior muscular impression ovate, well defined, and distinct from the small pedal sear under the hinge, above and behind its upper end; posterior muscular impression broader and more shallow; pallial line usually well defined and provided with a shallow, rounded, or semi- circular sinus; hinge rather strong, with the three cardinal teeth well developed in each valve; the anterior two of the left valve and the pos- terior two of the right being more or less suleated; anterior lateral teeth long, linear, and not very prominent; posterior shorter and very remote from the cardinals; both anterior and posterior laterals very nearly smooth or minutely granulo-striate. ‘‘ Length of a medium-sized adult specimen, 1.62 inches; height, 1.28 inches; convexity, 0.92 inch. Some fragments indicate one-third greater size for the largest. . “Locality and position—Two hundred miles east of Denver City, on the Kansas Pacific Railroad, when they were found in a shaft at a depth of forty feet below the surface.” It also occurs in the Laramie strata of the valleys of Crow and Bijou Creeks, Northern Colorado. At the former locality many well-preserved examples were obtained, some of which are figured on plate 21. CORBICULA (LEPTESTHES) MACROPISTHA White. Plate 23, figs. 4 a, b, ¢, d, e, and f, Corbicula (Leptesthes) macropistha White, 1878, Bull. U. 8. Geol. Sur. Terr., vol. iv, p. 713. Shell small, longitudinally subelliptical or subovate, broader (higher) posteriorly than anteriorly, slightly gibbous or somewhat compressed in the central portion; test strong, but not massive; basal margin broadly convex; posterior margin truncating the shell, its direction be- ing almost perpendicular or inclining a little backward from below, and somewhat abruptly rounded to both the postero-dorsal and basal mar- gins; posterior cardinal margin broadly convex; anterior cardinal mar- gin nearly straight and directed obliquely downward and forward to the front, which is abruptly rounded to the base; beaks depressed, not well defined, not projecting above the hinge-margin, and situated about one- third the length of the shell from the front. Surface showing the usual lines and imbrications of growth; and well-preserved examples show that the former were so fine on a large part of the surface as to give it an almost polished aspect. Lateral teeth well developed and finely crenulate; cardinal teeth having the usual characteristics of the genus; pallial line somewhat distant from the margin; sinus shallow. Length of an average sized example, as indicated by the twenty or thirty specimens in the collection, 21 millimeters; height of the same, WHITE. } ot LARAMIE FOSSILS. 79 15 millimeters; thickness, both valves together, 10 millimeters. There are two or three examples in the collection which were obtained from a layer separated by only a few feet from the one containing the typical specimens, at the Crow Creek locality, which seem to belong to this species, but, as they have some slight modifications of form besides their greater size, they are referred to it with doubt, and the size of the spe- cies is given as above. This shell plainly belongs to the subgenus Leptesthes of Meek, but it is the smallest species yet known, as the type species is the largest. The species here described shows characteristics of the subgenus that were not mentioned by Meek in his diagnoses. The inner surface of each valve is marked by asomewhat broad, faintly raised, smooth ridge which traverses the valve nearly perpendicularly from beneath the beak to the basal border. This ridge is always faint, and in the species here con- sidered it appears to be formed by a sudden thickening of the whole test forward of the median portion of the shell, rather than by a linear elevation of shell substance, such as constitutes the so-called internal rib of some shells. The beaks are also small, and the umbones not so prominent in the case of all species of this subgenus, as they are in the typical forms of the genus, and especially in the subgenus Veloritina. The peculiar flattening of the umbonal and upper and middle portions of the valves of C. (V.) macropistha, its greater width and equal if not greater thickness behind than in front, are characters by which the species may be readily recognized. Position and locality—Laramie Group; valleys of Crow and Bijou Creeks, Northern Colorado; associated with the last described and other species. CORBICULA (LEPTESTHES) SUBELLIPTICA Meek & Hayden. The type specimens of this species were collected by Dr. Hayden from the Judith River series of the Upper Missouri River region; and Mr. Meek also recognized it among some collections that were brought in by one of the parties of this survey from the valley of Bijou Creek, North- ern Colorado. I also collected it at the latter locality, where I found it associated with the preceding and other species. Mr. Meek described and figured it in vol. ix, U. 8S. Geol. Sur. Terr. (4to ser.), p. 523, plate 43. Subgenus VELORITINA * Meek. CORBICULA (VELORITINA) DURKEEI Meek. This species, which is the type of the subgenus Veloritina, has been found only in the Bear River series of the Laramie Group, where it is one of the most characteristic fossils. The typical examples were ob- tained in Bear River Valley, near the mouth of Sulphur Creek, but the Species is known to range as far south as Southwestern Utah, some ex- amples of it having been brought in by one of the parties under the direction of Lieutenant Wheeler; and figured and described by me in vol. iv, Expl. and Sur. West of the 100th Meridian. It is figured and described by Meek in vol. iv, U. 8. Geol. Sur. 40th Parallel (King), p. 167, pl. xvi, figs. 6 and 6 a, d, ¢, d, e, f, and g. This species, the type of the subgenus Veloritina, seems to be suffi- *For a diagnosis of this subgenus see vol. ix, U. 8. Geol. Sur. Terr. (4to ser.), p. 161. 80 GEOLOGICAL SURVEY OF THE TERRITORIES. ciently distinct from the typical forms of Corbicula to warrant its sepa- ration as proposed by Meek, but there are known forms that seem to connect the two types by direct gradation. C. cleburni, C. Occidentalis, and C. Cytheriformis seem to be such connecting forms, but perhaps © they might with propriety be referred to Veloritina. Genus CORBULA Bruguiere. CORBULA SUBTRIGONALIS Meek & Hayden. CORBULA PERUNDATA Meek & Hayden. CORBULA CRASSATELLIFORMIS Meek. CORBULA TROPIDOPHORA MEEK. In the annual report of this survey for 1877, p. 170, I placed all four of the above-named forms under one species, C. subtrigonalis, and I have since seen no cause to change my views upon that point, although it is true that selected examples of each form present differences that would be necessarily regarded as specific if no intermediate forms were known to connect them too nearly for specific separation. It is also true that at different localities this species presents recognizable varietal differ- ences, but these are doubtless due to different environing conditions while the mollusks lived. 2 Dr. Hayden obtained the type specimens of the two first-named forms from the Judith River series of the Laramie Group, in the Upper Mis- souri River region. They are deseribed by Meek in vol. ix, U. 8S. Geol. Sur. Ter. (4to ser.), pages 529 and 530, respectively, and figured on plate 40 of the same volume. Mr. Meek originally described both C. crassatelliformis and C. tropi- dophora from strata of the Bitter Creek series of the Laramie Group, the latter holding a position a few hundred feet lower in the series than the former. The latter is described in the annual report of this survey for 1872, p. 514, and the former (under the name Corbicula? crassatelliformis) in the report for 1870, p. 315. Both these forms are figured on plate 25, accompanying this article, together with others from Crow Creek, Col- orado, east of the Rocky Mountains. CORBULA MACTRIFORMIS Meek & Hayden. This species seems to be distinct from either of the four preceding forms, and yet it may perhaps prove to be only a variety. It has been found only inthe Laramie strata near Fort Clark, in the Upper Missouri River region, where it was discovered by Dr. Hayden. It is described and figured by Meek in vol. ix, U. S. Geol. Sur. Terr. (4to ser.), p. 528, plate 43, figs. 7 a-f. CORBULA UNDIFERA Meek. Plate 29 figs 4 a, b, ¢, d, e, and f. Corbula undifera Meek, 1873, An. Rep. U. 8. Geol Sur. Terr. for 1872, p. 513. This well-marked species has proved to be a characteristic fossil of the Laramie Group west of the Rocky Mountains. The following is Mr. Meek’s description : “Shell of moderate size, trigonal subovate, rather convex, the in- equality of the valves not being very strongly marked, although always WHITE. ] LARAMIE FOSSILS. 81 obvious; beaks moderately prominent, that of the left valve being only a little more elevated than that of the other, located in advance of the middle, contiguous, incurved, with a scarcely perceptible, forward inclination ; posterior extremity subangular at the connection of its margin with the base; posterior dorsal slope more or less convex in outline; anterior margin rather short and rounded; base semi-ovate in outline, being most prominent anteriorly, and somewhat straightened behind; left valve about one-fourth less convex than the other, with posterior umbonal slope less strongly angulated ; surface of both valves ornamented with concentric ridges, eenerally small and regular on the umbonal region, but often swelling out into a few very prominent angu- lar folds with rounded depressions marked by distinct lines of growth and some small ridges between on the lower half of the valves ; ‘all the ridges and folds eenerally becoming obsolete behind the angular poste- rior umbonal slope, but continued forwar d to the front. “Length of a well-developed specimen, 0.76 inch; height to top of umbo of left valve, 0.56 inch; convexity of the two valves united, 0.41 inch. “ Locality and position.—Rock Springs Station, Central [ Union] Pacific Railroad, Wyoming Territory. Upper part of the Bitter Creek series.” Typical forms of this species have been found in the valley of White River, Northwestern Colorado, near the base of the Laramie Group there, which shows it to range nearly or quite through the whole thickness of the group. Figs. 4a and b, on plate 29, are of an unusually large ex- ample, from Rock Springs. CORBULA UNDIFERA, var. SUBUNDIFERA. Plate 29, figs. 5 a, b, and c. Corbula subundifera White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 129. This form was originally described by me as a distinct species, but it is So very nearly related to C. undifera, the form just described, that I am now disposed to regard it as only a variety of that species. I how- ever give it a separate description and illustration in this article, be- cause it is so constant in the minor differences which distinguish it from the typical form, and because those differences are recognizable at widely separated localities, examples of this variety having been brought by Professor Powell from Upper Kanab, Southern Utah. Shell of ordinary size; marginal outline subtrihedral or subovate ; valves only slightly unequal; beaks contiguous; umbones moderately prominent; beaks incurved and directed a little forward; front obliquely truncate, concave, producing indistinctly defined anterior umbonal ridges; abruptly rounded below to the basal margin, which is broadiy rounded ; posterior extremity low, prominent, and shar ply rounded; postero-dor sal margin sloping from the dorsum to the posterior extremity; this margin of each valve is bent abruptly inward and downward, pr oducing a nar- row, shallow furrow, bordered at each side by a somewhat prominent ridge, which extends from behind the beak to the posterior extremity of the shell. Surface marked by numerous more or less strongly elevated concentric folds, which disappear before reaching the posterior margin, and are usually less distinct in front than upon the sides. Between these folds, and upon those parts of the surface unmarked by them, there are ordinarily distinct concentric lines of growth. Length, 25 millimeters; height, 18 millimeters. Position and localit y.— With ‘the exception of the Southern Utah spec- 6H 82 GEOLOGICAL SURVEY OF THE TERRITORIES. imens before referred to, this form has been found only at Point of Rocks Station, Union Pacific Railroad, Wyoming, in the upper strata of the Bitter Creek series of the Laramie Group, a few hundred feet above those in which the Mr. Meek’s types of O. undifera were discovered. CORBULA PYRIFORMIS Meek. This species is peculiar to the Bear River Laramie series, and at most of the known localities at which those strata are exposed it is one of the most abundant forms. C. englemannt Meek, an associated form, I regard as only a variety of C. pyriformis. Both forms are described in vol. iv, U.S. Geol. Sur. 40th Parallel (King), pages 170 and 174, respect- ively, and both are figured on plate xvii of the same volume. GASTEROPODA. Genus RHYTOPHORUS* Meek. RHYTOPHORUS PRISCUS Meek. The type specimens of this species, which are also the types of the genus, were obtained from the Bear River Laramie series, near the mouth of Sulphur Creek, in the valley of Bear River, Southwestern Wyoming, in which neighborhood only it has yet been discovered. It is described and figured in vol. iv, U.S. Geol. Sur. 40th Parallel (King), page 175, plate xvii. figs. 6 and 6 a; and also in Captain Simpson’s Report of the Great Basin of Utah, p. 364, plate v, figs. 4 a and b. Under the head of Melampus antiquis, on page 24 of this volume, I have suggested that the species described by Meek under that name from the Cretaceous series at Coalville, Utah, may perhaps belong to this genus. Unless this shall prove to be the case, the genus Rhytophorus is yet known only in the Bear River Laramie series, and the only known species are R. priscus, the type of the genus, and R. meekii White, which is associated with it, and which is described in the next following par- agraphs : 2 RHYTOPHORUS MEEKII White. Plate 30, figs. 8 a and bD. Shell subfusiform, spire moderately produced, nearly one-third the length of the entire shell; volutions about six, convex, the last one somewhat large, elongate, subterete, gently tapering from about its mid- dle to the anterior end; suture impressed, and upon the proximal side of and near it there is an almost equally impressed revolving line or narrow furrow, having the appearance of a second suture; one fold of the columella moderately well developed, and another less so. Surface marked by the ordinary lines of growth; and also, upon the spire, by numerous small varices or longitudinal folds, which cross the volutions nearly parallel to the lines of growth, and which are slightly oblique to the axis of the shell. These varices appear only upon the distal por- tion of the last volution, while they cross the entire exposed portion of those of the spire. Length of the largest example discovered, 25 millimeters; diameter of the body volution of the same, 12 millimeters. -* For Mr. Meck’s diagnosis of this genus see vol. iv, U. 8. Geol. Sur., 40th Parallel {King), p. 175. WHITE. ] LARAMIE FOSSILS. 83 This species differs from R. priscus Meek, with which it is associated, in the less robust and more elongate form of the shell, its proportionally longer spire, more delicate and finer surface markings, and the less ab- rupt convexity of the volutions upon the proximal side of the suture. Position and locality.—This form has yet been found only in strata of the Bear River Laramie series, near the mouth of Sulphur Creek, Bear River Valley, Wyoming, where it is associated with R. priscus, and numerous other molluscan forms characteristic of that series. Genus ACROLOXUS Beck. ACROLOXUS MINUTUS Meek & Hayden. This is the only species belonging to the Ancylide that has yet been discovered in any strata of the Laramie Group. It was obtained by Dr. Hayden from the Laramie strata, near Fort Union, in the Upper Missouri River region, and is described and figured in vol. ix, U. 8. Geol. Sur. Terr. (4to ser.), p. 543 plate 44, fig. 10. Genus PLANORBIS Miller. PLANORBIS CONVOLUTUS Meek & Hayden. The Planorbis section of the Limneide is not well represented among the pulmonate molluscea of the Laramie Group. Besides the three forms here noticed, all of which are from Laramie strata of the Upper Missouri River region, only one other form is yet known in the whole Laramie Group, although other fresh-water species of both pulmonate and branch- iferous mollusks are common, and species of Planorbis are also common in the fresh-water formations that succeeded the Laramie Group. The excepted species referred to is a small undescribed form from the Bear River Laramie strata near the mouth of Sulphur Creek, in Bear River Valley, which is properly referable to the subgenus Gyraulus Agassiz. It should be remarked, however, that another form, Planorbis (Bathy- omphalus) kanabensis White, has been discovered by Professor Powell in strata which he is understood to regard as equivalent to the Laramie Group, at Upper Kanab, Southern Utah; which species is noticed in the introductory remarks of this article. It is an interesting fact that the subgenus Bathyomphalus as well as Gyraulus was introduced thus early. Indeed it is probable that these two subgenera were introduced as early if not earlier than the form which is usually regarded as the typical of the genus. P. convolutus is described and figured in vol. ix, U. 8. Geol. Sur. Terr. (4to ser.), p. 536, plate 42, figs. 12 a and D. Subgenus BATHYOMPHALUS Agassiz. PLANORBIS (BATHYOMPHALUS) AMPLEXUS Meek & Hayden. See vol. ix, U.S. Geol. Sur. Terr. (4to ser.), p. 539, plate 42, figs. 16 a, b, c, d, and e. PLANORBIS (BATILYOMPHALUS) PLANOCONVEXUS Meek & Hayden. See vol. ix, U. S. Geol. Sur. Terr. (4to ser.), p. 538, plate 44, figs. 9 a, b, and ¢. 384 GEOLOGICAL SURVEY OF THE TERRITORIES, Genus LIMNASA Lamarck LIMN 2A NITIDULA Meek. In some of the layers of the Bear River Laramie series, near the mouth of Surphur Creek, Bear River Valley, Wyoming, this Species occurs quite plentifully, where alone it has yet been discovered. It is described and figured in vol iv, U. 8S. Geol. Sur. 40th Parallel ae p. 181, plate ie figs. 5 and 5a. Subgenus PLEUROLIMNZA* Meek. LIMN aA (PLEUROLIMN AA) TENUICOSTATA Meek & Hayden. Dr. Hayden obtained the types of this species, which are also the types of the subgenus, from the Laramie strata near Fort Union, in the Upper Missouri River region, where alone it has ever been found. Mr. Meek established the subgenus for this species alone, no other having yet been discovered. It is described and figured in vol. ix, U. S. Geol. Sur, Terr. (4to ser.), p. 534, plate 44, figs. 13 a, b, and ¢. Genus ACKLLA Haldeman. Plate 30, figs. 9 a and b. Acella haldemani White, 1878, Bull. U. S. Geol. Sur. Terr., vol. iv., p. 714. Shell very small and very slender; spire longer than the aperture; volutions about six and very obliquely coiled, slightly convex; last one not very ventricose; aperture only slightly, if at all, expanded, its outer margin, as Shown by the lines of growth, being nearly parallel with the axis of the shell. Surface marked numerous fine linear raised lines corresponding with lines of growth with spaces between them about equal to the lines, their direction being nearly or quite parallel with the axis of the shell upon the volutions of the spire, as well as upon the body volution. These lines, owing to the minute size of the shell, are distinguishable only under a lens of considerable power. Length, 6 millimeters ; diameter of last volution, 14 millimeters. This form seems unmistakably to belong to Acella Haldeman. It is the only species of that genus that has yet been found fossil in Ameri- can strata of any age, if we except an undescribed form in the Green River Eocene Group of Wyoming; and is especially interesting as show- ing the early establishment of that type among the Limneide. Meek regarded Acella as only a subgenus under Limncea, and possibly he was right, but as the type has been so long established in nature, and the limits of genera are of very unequal distinctness and value, I prefer to regard if here as a full genus. Genus PHYSA Draparnaud. PHYSA FELIX White. Plate 22, fig. la. Physa felix White, 1878, Bull. U. S. Geol. Sur. Terr., vol. iv, p. 714. Shell large; body volution inflated, shouldered at the distal border by an abrupt rounding of that part from the outer surface, the shoul- i ee ‘35h Meek’s diagnosis of this subgenus, see vol. ix, U. S. Geol. Sur. Terr. (4 to ser.), p el LARAMIE FOSSILS. 85 dered portion near the suture being at nearly right angles with the axis of the shell; spire comparatively small, and apparently only moderately elevated. Surface marked by the usual lines of growth, and upon the whole shouldered portion of the body volution, that is its distal portion, reaching to the suture, there are numerous small obliquely triangular papillz, which are arranged in oblique rows that coincide nearly with the lines of growth. Full length not accurately known, but the body volution of the type specimen was, when perfect, not less than 38 millimeters in length. — Only two fragments of this remarkable Physa have been discovered, but the characters shown by them, as recorded above and illustrated by figure 1 a on plate 22, are suéficient to distinguish it from any other species, either fossil or recent. When more perfect examples are found, it is not improbable they will shew characters that will require it to be separated, at least subgenerically, from the typical forms of Physa, as well as from other recognized sections of the genus. Position and locality.—Laramie Group; valley of Crow Creek, North- ern Colorado, about ten miles above the confluence of that creek with Platte River; where it was found associated with numerous other fresh- water mollusks, which are described in this article. PHYSA COPEI White. Plate 24, figs. 4 a and 6. Physa-copei White, 1877, Bull. U. 8. Geol. Sur. Terr., vol. iii, p. 602. Shell large, elongate subelliptical; volutions about four; body volu- tion large and moderately inflated; spire short, less than one-third the entire length of the shell; suture distinct but not deep; aperture elongate subovate in outline; callus of the inner lip moderately thick; surface marked only by the ordinary faint lines of growth common to the genus. Length, 50 millimeters; diameter of body volution, 25 millimeters. This fine Physa is the largest species known to me except P. pleuro- matis White, from the Wahsatch Group of Colorado, Wyoming, and Utah, some unusually large examples of which occur in the valley of White River, Northwestern Colorado. Position and locality.—The only known examples of this species were discovered by Prof. E. D. Cope in Laramie strata, near Cow Island, Upper Missouri River, Montana. PHYSA 2 Plate 30, fig. 11 a. A single example, found in the strata of the Bear River Laramie series, is figured on plate 30. It is the only specimen belonging to the Physidé that has yet been found in that series, and is probably a new form, but it is too imperfect for specific description, especially as the species of all that family of shells have few salient characteristics. Perhaps it should be referred to Bulinus rather than to Physa. It is given a place in this article to show that the family is represented in the Bear River series, and to make this synopsis of the molluscan fauna of the Laramie Group as complete as possible. 86 GEOLOGICAL SURVEY OF THE TERRITORIES. Genus BULINUS Adanson. BULINUS ATAVUS White. Plate 24, figs. 5 a and b. Bulinus atavus White, 1877, Bull. U. S. Geol. Sur. Terr., vol. iii, p. 601. Shell large, much elongated; volutions about seven, increasing gradu- ally in size; moderately convex; suture distinct but not deep; callus of the inner lip thin or absent; surface smooth, or marked only by very faint and very fine lines of growth. Some of the specimens have the appearance of having been naturally truncated or abruptly terminated at the apex, but it is more probable that this condition is the result of accident or erosion. Length, 50 millimeters, or more if the apex of the example measured be restored; diameter of body volution, 26 millimeters; length of aper- ture, 24 millimeters; full length of the spire beyond the aperture about equal to that of the aperture. This species is remarkable for its great size and unusually elongate form, which features render it so conspicuously different from any other known form as to make detailed comparison unnecessary. It is also so unusually elongate as to suggest that it may prove to be the type of a separate section of the genus Bulinus. Position and locality.—Judith River series of the Laramie Group; val- ley of Dog Creek, a tributary of the Upper Missouri River, where it was discovered by Prof. E. D. Cope. BULINUS DISJUNCTUS White. Plate 24, figs 6 a and bD. Bulinus disjunctus White, 1879, An. Rep. U. 8. Geol. Sur. Terr. for 1877,* p. 170. Shell rather large and moderately elongated; volutions about six, those of the spire increasing gradually in size, but the body volution is proportionally more inflated than those of the spire; suture distinct, but not deep, and not conspicuous, because of the moderate convexity of the volutions; length of the spire a little more than half that of the whole shell; callus of the inner lip broad, its posterior half closely appressed against and adherent to the body; its anterior half deflected or disjoined from the body, so as to leave a kind of umbilical space between it and the body of the shell. This condition of the inner lip is evidently not accidental, as it is present upon all the examples, young and old, that have yet been found; aperture moderately large, its length a little more than half the full length of the shell. Surface marked only by the fine lines of growth peculiar to the Physide. Length, about 43 millimeters; breadth of body volution, 20 millime- ters. This shell resembles B. subelongatus Meek & Hayden, from the Lara- mie strata of the Judith River series, Upper Missouri River region; *In the original description of this species I compared it with ‘“ Bb. elongatus Meek & Hayden.” B. subelongatus was intended, the error haying occurred by copying from one of the labels accompanying the type specimens. I have elsewhere inadvert- ently made a few similar errors in cases where the originally labeled name was changed upon publication. “WHITE. ] LARAMIE FOSSILS. 87 but the spire is proportionally more elevated, and consequently the body volution, although large, is proportionally smaller. Some examples of a Lulinus from the coal-bearing series near EHvans- ton, Wyo., which I at one time supposed to be identical with this spe- cies, Shows the same peculiarity of the inner lip, namely, the lifting of the anterior portion of the callus from the body of the shell. That, however, is probably a distinct species, and, if so, the peculiarity men- tioned, would seem not to be confined to this specific form alone. Position and locality.—Laramie Group valley of Crow Creek, North- ern Colorado, about ten miles above the contluence of that creek with Platte River. An example brought in by one of the parties of this Sur- vey from Separation Station, Union Pacific Railroad Wyoming, seems to belong to this species. BULINUS LONGIUSCULUS Meek & Hayden. BULINUS ? RHOMBOIDEUS Meek & Hayden. These two species are from the Laramie strata near Fort Union on the Upper Missouri River, where the types were collected by Dr. Hayden. The former has been identified with a good degree of certainty in the coal-bearing strata near Evanston, Wyo., and examples of a species apparently identical with the latter have been found associated with it. Mr. Meek describes these two forms in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), pages 441 and 442, respectively, and both of them are figured on plate 43 of the same volume. BULINUS SUBELONGATUS Meek & Hayden. Dr. Hayden also obtained the types of this species from the Judith River series of the Laramie Group, in the Upper Missouri River region. It has been identified with a good degree of certainty among fossils col- lected from the coal-bearing strata near Evanston, Wyo. It is described and figured in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), p. 540, plate 42, figs. 13 a and bD. Genus VITRINA Draparnaud. VITRINA ? OBLIQUA Meek & Hayden. The type specimen of this form, which evidently represents a well de- fined species, although its true relations are not accurately known, was obtained by Dr. Hayden from the Laramie strata of the Judith River series with the large collections which he obtained many years ago in the Upper Missouri River region. It is described and figured in vol. ix U.S. Geol. Sur. Terr. (4to ser.), plate 42, figs. 10 a and b. Genus HYALINA Férussac. HYALINA? OCCIDENTALIS Meek & Hayden. HYALINA? EVANSI Meek & Hayden. The types of these two species are also from the Judith River series of the Laramie Group; those discovered by Dr. Hayden being the only 88 GEOLOGICAL SURVEY OF THE TERRITORIES. examples of either of these two forms yet known. They are described by Meek in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), pages 547 and 548, respectively. The former is illustrated on plate 42, figs. 6 a, b, ¢, and d; and the latter is illustrated only by wood-cuts accompanying the description. Genus HELIX Linnzus. HELIX VETUSTA Meek & Hayden. Dr. Hayden found this species associated with the preceding and many other species in the Judith River series. Itis deseribed by Meek in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), p. 552, and figured on plate 42 of the same.volume. Although the Helicidz were introduced at least as early as the Laramie period, and different divisions of the family were then distinctly differentiated, the family is not abundantly represented in that group. Genus THAUMASTUS Albers. THAUMASTUS LIMN4IFORMIS Meek & Hayden. Discovered by Dr. Hayden in the Laramie strata near the mouth of Yellowstone River, Montana. It is described and figured in vol. ix, U. S. Geol. Sur. Terr. (4to ser.), p. 553, plate 44, figs. 8 a, b, c, and d. Genus COLUMNA Perry. COLUMNA TERES Meek & Hayden. COLUMNA VERMICULA Meek & Hayden. Both of these species were found associated together by Dr. Hayden in the Laramie strata, at the mouth of Judith River, Montana. They are described in vol. ix, U. S. Geol. Sur. Terr. (4to ser.), pages 555 and 506, respectively, and figured on plate 44 of the same volume. Genus NERITINA Lamarck. NERITINA VOLVILINEATA White. Plate 21, figs. 6 a and b. Neritina volvilineata White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 131. Shell small, subcireular in lateral outline; volutions three and a half or four; the last one regularly convex; spire short, but quite as promi- nent as is usual in species of this genus; suture slightly impressed; aper- ture semi-lunar; inner lip broad, plain, flat, its inner edge not clearly seen, but it is apparently plain. Surface marked by numerous raised revolving lines of unequal size, which increase in number by implanta- tion as the shell increases in size, the lines also gradually increasing in size for a portion of their length after their origination; the spaces be- tween the raised lines about equal to or a little less than the lines in width; the revolving lines crossed by the usual lines of growth, which gives the surface, upon some parts at least, an indistinctly cancellated appearance under the lens. Greatest diameter of the largest example among those first discovered at Black Buttes Station, 9 millimeters; height, the shell lying with its aperture upon the table, 5 millimeters. Some examples atterward dis- covered in the valley of Yampa River are much larger. WHITE.] LARAMIE FOSSILS. 89 Position and locality.—Laramie strata, near the top of the group; Black Buttes Station, Union Pacific Railroad, Wyoming; and valley of Yampa River, near Canon Park, Northwestern Colorado, where also its position is near the top of the group. NERITINA NATICIFORMIS White. Plate 30, figs. 3 a and b. Neritina naticiformis White, 1878, Bull. U. S. Geol. Sur. Terr., vol. iv, p. 715. Shell very small, subglobose, its aspect being more nearly like that of Natica than that of the usual forms of Neritina ; spire moderately prom- inent; volutions three or four, increasing so rapidly in size that the last one comprises much the greater part of the bulk of the shell; all the volutions regularly convex; suture distinct; test not massive; aper- ture large, nearly straight on the inner side, the remainder of its border forising a continuous and almost uniform curve, the whole comprising more than a semi-circle; edge of the outer lip thin; inner lip not very broad, flattened, apparently smooth both upon its surface and inner edge, sloping strongly inward, or away from the border of the aperture, its Inner margin somewhat concave. Surface marked only by ordinary distinct lines of growth, except that in one or two instances traces of revolving striz have been detected upon the proximal or lower portion. Extreme length from apex to front margin, 6 millimeters; greatest diameter across the middle of the aperture, about the same. In general aspect this little shell so closely resembles a Natica that, the aperture being filled with the imbedding material, the first sugges- tion whether it might not belong to that or a closely-related genus came from its association with fresh and brackish water forms. Upon break- ing up some of the examples the inner lip was found to be more charac- teristic of Neritina than Natica, although it is not so broad and thick as it usually is in typical forms of the former genus; from which the shell in question also departs by the comparative thinness of the test. The genus Neritina is not very well represented in the Laramie Group, no example of any species of it having yet been discovered in the Upper Missouri River region which has furnished so many other specific forms, and only three species have been found in the group elsewhere, includ- ing the next described form under the subgenus Velatella. It was more common in the preceding Fox Hills epoch, but it appears to have been entirely absent from the fresh waters in which the Tertiary deposits were made, that immediately succeeded those of the Laramie Group. Position and locality—Bear River, Laramie series, pear the mouth of Sulphur Creek, Valley of Bear River, Wyoming, where it was found as- sociated with Limnea vetusta, Acella haldemani, and other forms, in a layer both above and beneath which are those that contain an abun- dance of the characteristic brackish and fresh water species of that series. Subgenus VELATELLA* Meek. VELATELLA BAPTISTA White. Plate 29, figs. 6 a and b. Velatella baptista White, 1878, Bull. U. S. Geol. Sur. Terr., vol. iv, p. 715. Shell small, elliptical in lateral outline, broadly convex above, the con- vexity of the postero-median portion being greater than it is elsewhere, 90 GEOLOGICAL SURVEY OF THE TERRITORIES. nearly flat beneath; umbo somewhat prominent, nucleus or apex pos- terior, minutely subspiral and depressed almost closely upon the poste- rior margin, small, closely incurved and turned towards the right side ; inner lip broad, smooth, slightly convex in all directions, and occupying ~ fully one-half of the whole under surface of the shell; outer lip appar- ently moderately thin, but this feature has not been clearly seen. Surface so nearly smooth as to give the shell an almost polished appearance, but under the lens minute striz of growth are visible; and also near the borders minute radiating stiiz are seen, apparently in the substance of the shell. There are, also, upon the only example yet discovered, seven or eight irregular radiating stripes of coloration of the test. These are now brownish in color, while the general surface is buff; both of which colors are doubtless now different from those which characterized the shell while the mollusk was living, but the pattern of ornamentation is no doubt correctly preserved. Length, 10 millimeters; breadth, 7 millimeters; height, 5 millimeters. This species resembles in many respects, WV. (V.) patelliformis Meek, especially the variety Weberensis White; but it differs from the former in _ Shape, and from the latter in being without any trace of radiating raised lines or costé, in the greater prominence of the umbonal portion, and its somewhat more conspicuous apex. Its coloration is not taken into ac- count in this comparison because its preservation in this species and not in the other is thought to be only accidental. Position and localityx—Laramie Group; Black Buttes Station, Union Pacific Railroad, where it was found associated with the majority of the species of Unio described in this article, besides Corbicula (Leptesthes) fracta, and other mollusks. Genus CERITHIDEA Swainson. Subgenus PIRENELLA Gray. CERITHIDEA (PIRENELLA) NEBRASCENSIS Meek & Hayden. For description and illustration of this species, see vol. ix, U.S. Geol. Sur. Terr. (4to ser.), p. 559, pl. 43. Dr. Hayden obtained the types, which are the only examples yet discovered, from Laramie strata, near the head of Little Missouri River. Genus GONIOBASIS Lea. Thirteen or fourteen specific fossil forms have been obtained from the strata of the Laramie Group in different portions of the great region which it largely occupies, which authors have generally referred to the - genus Goniobasis of Lea. ‘These species may be separated into certain more or less distinct groups by characteristics which they respectively possess. Two or three of these suggested groups possess characteristics which may, perhaps, prove to be of at least subgeneric importance, but more material is necessary before such a study of them can be satisfae- torily made. At present, three sections seem to be indicated, of which G. cleburni, G. nebrascensis, and G. gracilenta may be taken respectively as the types. Perhaps also the form which, in a following description, I have referred to Melania (M. wyomingensis) may be regarded as the type of only a section of Goniobasis co-ordinate with these, and not properly referable to Melania. At present, however, | prefer to make the follow- ing references of these forms, hoping at a future time to study them ex- haustively. Seni Re LARAMIE FOSSILS 91 GONIOBASIS CLEBURNI White. Plate 30, figs. 4 a, b, c, and d. Turbonilla (Chemnitzia) melanopsis White, 1875 (not Conrad), Expl. and Sur. West of the 100th Merid., vol. iv, p. 197, pl. xviii, fig. 10 a. Goniobasis cleburni White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 122. Shell rather large, gradually tapering from the last volution to the apex, the sides of the spire being only slightly convex; volutionsapparently nine or ten, gradually increasing in size, the last one not being proportionally larger than the others ; suture slightly impressed; sides of the volutions of the spire nearly flat, or only slightly convex, but the outer and anterior sides of the last one having a broad and regular convexity; aperture, as indicated by the lines of growth, subovate in outline; outer lip broadly sinuate. Surface of the spire marked by numerous strong longitudinal ridges or varices, extending from suture to suture, which are slightly flexed and slightly oblique to the axis of the shell, or approximately parallel with it; the proximal side of the last volution marked by sev- eral faint revolving lines, the longitudinal varices of the last volution ending before reaching that portion of the surface do not appear there. The lines of growth are usually stronger upon the last volution than elsewhere, and the varices are sometimes obsolete, at least upon a por- tion of its surface. Revolving lines have not been observed upon the surface of the spire, but sometimes the edges of the longitudinal varices are seen to be faintly crenulate, as if by incipient revolving lines. Although a considerabie number of specimens have been collected, none have been found with the apex complete, but the length of a full- grown specimen is estimated from those obtained at about 50 millime- ters ; diameter of the last volution, 19 millimeters. : ‘IT now think that the shell, which in vol. iv, Expl. and Sur. West of the 100th Mezid., p. 197 pl. xviii, fig 10 a, I doubtfully referred to Turbo- milla (Chemnitzia) melanopsis Conrad, and which was obtained from South- western Utah, really belongs to this species. ‘This opinion is supported by the fact that Corbicula ( Veloritina) durkeei Meek, was reported from the same locality, and which is also figured in the volume quoted; plate xxi. This being the fact, the geographical range of G. cleburni is seen to be very great. Position and locality.—The types of this species were obtained from the Bear River Laramie series, near the mouth of Sulphur Creek, Bear River Valley, Wyoming. Examples of it, more or less perfect, have been found at all, or nearly all, the localities at which the Bear River Laramie series has been recognized. It is, therefore, one of the more characteristic species of that series of strata. GONIOBASIS CHRYSALLIS Meek. Plate 30, figs. 6 a and b. Goniobasis chrysallis Meek, 1871, An. Rep. U. S. Geol. Sur. Terr. for 1870, p. 316. The following is Mr. Meek’s original description of this species: “Shell generally almost cylindrical below the middle, but more ab- ruptly tapering above; volutions six or seven, flattened, with the upper margin thickened, last one not angular, and scarcely larger than the next above it; suture well defined. “Surface ornamented by distinct vertical costs, often ranged nearly in the same line all the way up the spire; these are partly interrupted 92 GEOLOGICAL SURVEY OF THE TERRITORIES. by an effort to form three, or rarely four, obscure revolving lines or ridges, the upper of which is larger and more prominent than the others, which character, with the slightly enlarged upper ends of the vertical coste, causes the thickened appearance of the upper margins of the volutions; several other slender and more distinct revolving lines also occur on the under side of the last turn. Aperture somewhat rhombic-ovate. ‘Length, about .60 inch; breadth, .18 inch.” This shell is plainly related to G. cleburni, with which it is associated, but its comparatively minute size and the details of its form show dif- ferences too great to require detailed comparison. It has been found in considerable numbers in the Bear River Laramie series, near the mouth of Sulphur Creek, Bear River Valley, Wyoming; where it is associated with many other species, including those which are most characteristic of the series. GONLOBASIS CHRYSALLOIDEA White. Plate 30, figs. 5 a and 6. Goniobasis chrysalloidea White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 123. Shell of medium size, gradually tapering from the last volution to the apex; volutions about seven or eight, those of the spire slightly con- vex, the last one broadly rounded to the anterior end; suture impressed, the apparent impression being increased by the projecting fold of the distal border of each volution, which is appressed. against the next pre- ceding one. Surface marked by more or less distinct longitudinal, slightly-bent ridges or varices, which are crossed by several revolving lines that appear only on the ridges, and not between them, giving the ridges a knotted or crenulated appearance; anterior surface of the last volution also marked by distinct raised revolving lines. Length, 28 millimeters ; diameter of the last volution, 9 millimeters. This species is closely related to both G. cleburni and G. chrysallis, with both of which forms it is associated. It differs from the latter in its much larger size, much greater apical angle, straighter sides of the spire, and in the details of its ornamentation. It differs from G. cleburni in its smaller size, the more distinct crenulation of its longitudinal varices or folds, and in possessing the revolving fold-like projection of the distal border of its volutions. Position and locality——Bear River series of the Laramie Group, near the mouth of Sulphur Creek, Bear River Valley, Wyoming. GONIOBASIS ENDLICHI White. Plate 30, figs. 7 a, b, and ¢. y Goniobasis endlicht White, 1878, Bull. U. S. Geol. Sur. Terr., vol. iv., p. 716. Shell moderately elongate-conical; spire with straight or slightly concave sides; volutions six or seven, much, and nearly regularly, con- vex, the last one slightly inflated ; suture well defined, and appearing unusually deep on account of the convexity of the volutions; aperture subovate in outline, its distal end angular, its front somewhat narrowly rounded and without a sinus; outer lip apparently sharp; inner lip with a thin reflected callus, which is more developed anteriorly than posteriorly ; columella gently arcuate. . Surface marked by fine but distinct lines of growth, which are crossed by very numerous fine, revolving, raised lines, giving it a cancellated WHITE.] LARAMIE FOSSILS. 93 appearance under the lens. In addition to these, there are usually from four to six much larger, nearly equidistant, revolving raised lines of nearly equal size upon the visible portion of the volutions of the Spire, and ten or twelve of them upon the body volution. These larger revolv- ing raised lines are sometimes absent or obsolete, but the smaller mark- ings first mentioned are always present. Length, about 22 millimeters; diameter of body volution, 11 milli- meters. This species is evidently nearly related to G. nebrascensis Meek & Hayden, and ought, perhaps, to be referred to Pachycheilus Lea, but the difficulty of learning the exact character of the outer lip leaves the mat- ter in some doubt. Position and locality.—Bear River series of the Laramie Group, seven miles northward from Evanston, in the valley of Bear River, where it is associated with many of the characteristic species of that series. GONIOBASIS MACILENTA White. Plate 30, fig. 10 a. Goniobasis arcta White (not Meek), 1879, An. Rep. U.S. Geol. Sur. Terr. for 1877, p. 244. Shell small, slender, terete; test thin; sides of the spire straight ora little concave; volutions, apparently ten or more, gradually increasing in size, their sides flat and forming the continuous surface of the straight sides of the shell; suture linear; surface marked by lines of growth, which cross the volutions with a slightly sinuous course, but nearly in line with the axis of the shell. Near the distal border of the volutions there is a revolving depressed line, which has the appearance of a second suture. There appears to be no tendency to form longitudinal varices such as mark G. cleburni, G. chrysallis, and other species, nor have other revolving lines than the one already mentioned been detected. The length of the type specimen, when perfect, was about 12 millime- ters; diameter of the last volution, a little more than 2 millimeters. A less perfect example, the largest in the collection, indicates about double that size. Upon the first discovery of this species I supposed it to be identical with G. arcta Meek, which he described in Simpson’s Report on the Great Basin of Utah, p. 366, as from the Tertiary strata of the valley of Ham/’s Fork, a tributary of Green River. That form is closely like the one in question in general aspect, and I was led to believe a mistake had occurred in giving its location similar to one made in regard to Limneea mitidula in the same connection, and which he afterward corrected. A careful study of our examples shows that they cannot be referred to that species, and I therefore apply to it a new specific name. The per- fectly flattened sides of all the volutions of the spire, with the linear suture and its companion impressed line, distinguish it from all other known species. The companion line of the suture of this species seems to have more Significance than as a mere specific character, from the fact that it is more or less distinctly represented in both G. chrysallis and G. chrysal- loides, both of which species are from the same series of strata and from the same locality that furnished the type specimens of this species. Position and locality—Bear River series of the Laramie Group, near the mouth of Sulphur Creek, valley of Bear River, Wyoming. 94 GEOLOGICAL SURVEY OF THE TERRITORIES. GONIOBASIS GRACILENTA Meek & Hayden. The type specimens of this species were discovered by Dr. Hayden in the Judith River series of the Upper Missouri River region. It is — described and figured in vol. ix, U. S. Geol. Sur. Terr. (4to ser.), p. 568, pl. 42, fig. 3. Ihave recognized the species among the Laramie fossils collected in the valley of Crow Creek, Northern Colorado; and among those of Black Buttes Station, in Southern Wyoming, is a form which, although rather more delicate ‘than the type specimens of-the species, appears to be identical with it. GONIOBASIS CONVEXA Meek and Hayden. GONIOBASIS INVENUSTA M. & H. GONIOBASIS SUBLAEVIS M. & H. GONIOBASIS? OMITTA M. & H. GONIOBASIS? SUBTORTUOSA M. & H. These five species were collected by Dr. Hayden from the Judith River series of the Laramie Group, near the mouth of Judith River, Montana. They are described in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), pages 562, 564, 567, 568, and 569, respectively; and all are figured on plate 42 of the same volume. The last-named species is almost certainly not a Goniobasis, but it perhaps belongs to the genus Cassiopella White. GONIOBASIS NEBRASCENSIS Meek & Hayden. GONIOBASIS TENUICARINATA M..& H. These two species were originally discovered by Dr. Hayden in the Fort Union series in the Laramie strata, in the Upper Missouri River region. They are described in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), pages 565 and 566, respectively, and both are figured on plate 45 of the same volume. The former species has been obtained by myself from the Laramie strata of Crow Creek, Northern Colorado, and I identified it also among some fossils brought by Professor Powell from the Canon of Desolation, Green River, Utah. Both species are also coutained among Lieutenant Wheeler’s collections from Wales, Utah, which were described and figured by me in vol. iv, Expl. and Sur. West of the 100th Merid., pages "212 and 213, pl. xxi, figs. 9 and 10. Genus MELANIA Lamarck. MELANIA ? INSCULPTA Meek. Plate 20, fig. 4 a. Melania? insculpta Meek, 1873, An. Rep. U. 8S. Geol. Sur. for 1872, p. 515. The following is Mr. Meek’s description of this species, together with his remarks upon it: ‘¢ Shell terete or elongate subconical ; volutions apparently about ten, convex, or sometimes flattened convex, increasing gradually in size ; last one not much enlarged and without an angle around the middle, some- times slightly concave above in large specimens; suture well defined ; aperture unknown. Surface ornamented with distinet, nearly straight or slightly arched vertical costz, about sixteen of which’ may be counted on each volution, while crossing these are smaller, regular, deep revolv- ing furrows that cut each rib into five or six little transverse nodes which, WHITE. ] LARAMIE FOSSILS. 95 from the obsolescence of the vertical cost on the lower part of the last turn, become more or less continuous revolving lines on that part of the shell. ‘« The specimens of this species yet obtained are too imperfect to af- ford the means of giving accurate measurements. Judging, however, from some of those in the collection, large adult individuals would seem to have attained a length of 1.40 inches, with a breadth of body volu- tion of near 0.50 inch. Some of these larger specimens, consisting of three or four of the lower volutions, show but a very gradual de- crease in breadth upward; while some of those composed of the upper part of the shell indicate a divergence of about 18° for the angle of that portion of the spire. “As none of the specimens show the aperture, it is not possible to de- termine from those yet seen whether this shell really belongs to the fresh-water genus Goniobasis or to some marine genus, although the spe- cies will be readily recognized by its seulpturing. Its only known as- sociates are fragments of Ostrea and Modiola, with Corbula undifera, an association that would certainly favor the conclusion that it should be referred to a marine genus, in which case it would most probably fall into Bittium, and have to be called B. insculpta. ‘¢ We have, however, several examples of unquestionable fresh-water Shells associated with marine types in some of the rocks of this region ; while the general aspect of this shell seems, as far as known, to asso- ciate it with Goniobasis. The fact, too, that nearly all the specimens yet seen are fragmentary, seems to indicate that the species did not live in the same waters with the other forms found associated with it, but that the specimens may have been washed into the sea from streams on the neighboring shores. ‘“¢ Locality and position.—Rock Springs, Wyoming; from a little above the main 10-foot bed of coal at that locality. Bitter Creek series.” While this shell is almost certainly a fresh-water form, there is no positively known reason for referring it to the genus Melania proper. It is, however, almost certainly genetically related to the next described species, as I suggested in the report of this survey for 1877; and in view of the form and ornamentation of the species referred to, I prefer at present to retain it with that species in the genus Melania; and this form being so related to that one, both seem to require the same generic assignment. MELANIA WYOMINGENSIS Meek. Plate 28, figs. 6 a and b. Melania (Goniobasis?) wyomingensis Meek, 1873, An. Rep. U. 8S. Geol. Sur. for 1872, p. 516. Melania larunda White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 131. Shell large, elongate; volutions apparently eleven or twelve, uniformly increasing in size, moderately convex, the last five or six of them bear- ing about the middle or a little above it a revolving row of prominent, strong, outward-projecting, laterally compressed and somewhat sharp- ened tubercles. These tubercles are strongest upon the last volution and gradually diminish in size until they disappear among the crenulated lines that mark the volutions of the spire. They decrease in number also, there being about fifteen on the last volution, and about ten on that upon which they first appear. The upper volutions of the spire are marked by numerous crenulated longitudinal varices having a slight convex curve to the left side of the shell, the crenulations being caused 96 GEOLOGICAL SURVEY OF THE TERRITORIES. by the crossing of the varices by about five revolving raised lines which are distinct upon, but hardly appear between, the varices. The row of tubercles that mark the larger volutions begins by the gradual enlarge- ment of the crenulations of the second revolving line forward of the suture. The other revolving lines of the smaller volutions are con- tinued upon all the larger ones, but upon the latter they become more continuous and less distinctly crenulated ; and the two lines upon the distal side of the row of tubercles are usually obsolete upon the last two volutions. Besides the three revolving lines upon the proximal side of the row of tubercles before mentioned, the last volution shows upon its proximal side four or five other somewhat stronger ones, which, in the volutions of the spire, are successively covered by the orowth of the Shell. Lines of growth rather distinct; suture linear; columella flexed ; outer lip having a broad shallow notch, the retreating angle of which is opposite the row of tubercles; anterior portion of the lip moderately ex- tended and abruptly rounded to the columella. The length of a full-grown example, when entire, was probably not less than 100 millimeters; diameter of the last volution of the largest examples in the collection, 22 millimeters. This description is drawn mainly from my type specimens of M. lavunda, because they are much more perfect than Mr. Meek’s types are, and more perfect than any others yet discovered. In its aspect and ornamentation this species is so much like an Old World Melania that I prefer to assign it to that genus rather than to Goniobasis, with some forms of which it agrees in general characteristics. Position and locality.—Mr. Meek’s types were discovered in the upper strata of the Laramie Group at Black Buttes Station, Union Pacific Railroad, Wyoming. Examples of it were also obtained by me from very near the base of the group at Danforth Hills, near White River Indian Agency, White River Valley, Northwestern Colorado. The types used in its description, under the name of I/. larunda, were found in the valley of Crow Creek, Northern Colorado; and it has also been found at other places east of the Rocky Mountains in that State, Genus PYRGULIFERA* Meek. - PYRGULIFERA HUMEROSA Meek. The types of this species, which are also the types of the genus, were obtained from the Bear River series of Laramie strata, near the mouth of Sulphur Creek, Bear River Valley, Wyoming, in which district it is one of the most abundant and characteristic species of that series. It is described and figured in vol. iv, U.S. Geol. Sur. 40th Parallel (King), p. 176, pl. xvii, figs. 19 and 19a; and also in Captain Simpson’s Rep. Great Basin of Utah, p. 363, pl. 5, fig. 6a, b, and e. Genus CASSIOPELLA White. This genus was proposed in Bulletin U. 8. Geological Survey of the Territories, vol. iii, p. 606 (1877), to include the species first published under the name Letoplax ? turricula, in Powell’s Report Geology of the Uinta Mountains, p. 133. The diagnosis is also given here, because it is at present known only in strata of the Laramie Group. * For diagnosis of this genus, see vol. iv, U.S. Geol. Sur, 40th Parallel (King), p. 176. WHITE.] LARAMIE FOSSILS. 97 Shell resembling Goniobasis in form and in some of its other charac- teristics; but, unlike that genus, it is distinctly umbilicated; volutions more or less convex or angulated; aperture more or less produced in front; subovate or rhomboidal in outline; outer lip sinuous; inner lip having a more or less distinct layer of callus. I have here placed this genus provisionally in the family Ceriphasiid:e of Gill; but I am not entirely satisfied that it really belongs in that family. Being umbilicated, it bears a similar relation to Goniobasis that Cassiope Coqnand does to Turritella; but of course it is not regarded as having any near affinities with Cassiope, which is a marine genus. CASSIOPELLA TURRICULA White. Plate 27, figs. 3 a, b, ¢, d, e, f, and g. Leioplax? turricula White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 133. Cassiopella turricula White, 1877, Bull. U. 8. Geol. Sur. Terr., vol. iii, p. 606. Shell elongate conical; the apical portion slender, the sides being slightly concave; volutions nine or ten, gradually increasing in size, prominent, angulated, the angle being prominent or subcarinated, and situated a little in advance of the middle of the exposed portion of the volutions of the spire; suture slightly impressed, but appearing deep in Seance of the prominence of the volutions; last volution broadly rounded from the prominent revolving angle to the verge of the umbili- cus; umbilicus narrow, deep, and marked within by two or three re- volving lines. Surface, upon both sides of the prominent angle of the volutions, marked more or less distinctly by two or three revolving raised lines ; and the proximal surface of the last volution is also marked by similar lines. Aperture subrhombic in outline. Length, 34 millimeters ; diameter of the last volution, 15 millimeters. Position and locality.—This is the type, and only known species of the genus; and it has hitherto been found only at Black Buttes Station, Union Pacifie Railroad, Wyoming, in the upper portion of the Laramie Group. It is associated in the same layer with Viviparus plicapressus, Tulotoma thompsoni, Campeloma multistriata, Goniobasis gracilenta, and several species of Uino. It is therefore referred to a fresh-water habitat, although many young examples of Corbula subtrigonalis were also found immediately associated with it. . Genus HYDROBIA Hartmann. HYDROBIA ANTHONYI Meek & Hayden. HYDROBIA WARRENANA Meek & Hayden. HYDROBIA SUBCONICA Meek & Hayden. HYBROBIA ? ENLIMOIDES Meek & Hayden. These four species were obtained by Dr. Hayden from the Laramie Group of the Upper Missouri River region, and none of them have yet been elsewhere identified. They are described on pages 571-573, vol. ix, U.S. Geol. Sur. Terr. (4to ser.), the two former being figured on plate 43 of that volume; but the two latter are illustrated by a wood-cut each, accompanying the descriptions. The genus Hydrobia has not been recognized elsewhere in the Lara- mie Group, if we except a species which was described by myself from the coal-bearing series near Evanston, Wyo., and another from certain of the strata exposed in the Caiion of Desclation, Green River, Utah. 7H 98 GEOLOGICAL SURVEY OF THE TERRITORIES. From the former I obtained H. recta White, and from the latter Pro- fessor Powell brought H. utahensis White. I have very little doubt that the strata of both those localities really belong to the Laramie Group, but, as before explained, they are not specially considered in this article, because more information concerning their stratigraphical relations is needed. Genus MICROPYRGUS* Meek. MICROPYRGUS MINUTULUS Meek & Hayden. This little shell is the type and only certainly known species of the genus. It was obtained by Dr. Hayden from the Laramie strata near Fort Union, on the Upper Missouri River, and is deseribed and figured in vol. ix, U. S. Geol. Sur. Terr. (4to ser.), p. 575, plate 43, figs. 18 a and b. Ihave seen fragments of a shell in the Green River Group of South- ern Wyoming that may perhaps prove to be another, and considerably larger, species of this genus. Genus VIVIPARUS . Montfort. VIVIPARUS PLICAPRESSUS White. Plate 28, figs. 3 a and D. Viviparus plicapressus White, 1876; Powell’s Rep. Geol. Uinta Mts., p. 183 Shell rather under medium size; spire conical, its sides eee straight ; _volutions about seven, moderately convex; the outer and anterior con- vexity of the last volution continuous and uniform; suture impressed. At the distal border of each volution there is a small, more or less dis- tinct revolving groove or furrow; and the narrow border between the furrow and the suture is in the form of a fold, which is closely appressed against the proximal side of the adjacent volution, the fold forming a shght projection or shoulder upon the proximal side of and bordering the suture. Surface marked by the ordinary lines of growth, and upon some examples there appears to be a faintly raised revolving line, or in- cipient angulation, near the middle of the outer side of the volutions. None of the examples in the collection are entire, but the length is estimated from the most perfect examples at about 25 millimeters; breadth of last volution, 12 millimeters. Position and locality.—Laramie Group, Black Buttes Station, Union Pacific Railroad, Wyoming; and also in the valley of Yampa Itiver, near Canon Park, Northwestern Colorado. VIVIPARUS PRUDENTIUS White. Plate 28, figs. 5a and b. Viviparus prudentia White, 1878, Bull. U. 8. Geol. Sur. Terr., vol. iv, p. 716. Shell depressed, subconical ; spire short, convex; volutions five and a half or six, including the minute ones of the apex, a all regularly con- vex; last one. considerably enlarged, and constituting the greater part ‘of the shell, rounded by an almost uniform curve from the suture to the umbilicus ; ‘suture well defined, its apparent depth increased by the bold convexity ’of the volutions ; umbilicus very small and deep; aperture ‘short, subovate or subcircular in outline; obtusely angular at its distal * For diagnosis of this genus see vol. ix, U. 8. Geol. Sur. Ter., (4to ser.,) p. 574. WHITE. | LARAMIE FOSSILS. 99 side; its outline a little straightened between the angle before mentioned and the verge of the umbilicus by contact with the body of the shell, but the remainder of the outline forming a continuous and almost regu- lar curve. Surface smooth, and having an almost polished appearance ; but it is marked by very fine lines of growth. Length from the front margin of the aperture to the apex, 18 milli- meters. This shell more nearly resembles the living species V. intertexta Say than any other known form; but it differs from that species in its some- what shorter spire, more distinct, though small, umbilicus, and the less prominently rounded distal side of the volutions. It also resembles V. leat M. & H., but it is a much shorter shell. Position and locality—Laramie Group, valley of Crow Creek, ten miles above the confluence of that creek with Platte River, Northern Colorado. VIVIPARUS COUESI White. Plate 30, fig. la. Viviparus couesi White, 1878, Bull. U. S. Geol. Sur. Terr., vol iv, p. 717. Shell very large when fully adult; volutions six or seven, convex, the distal side of the last one especially, abruptly rounded to the suture, giving it a somewhat shouldered aspect there, while the outer side is broadly convex and sloping gently forward and inward; suture deeply impressed, the apparent depth being increased by the great convexity of the volutions. Surface marked by the ordinary lines of growth, no revolving marks of any kind having been detected. The lines of growth indicate that the margin of the outer lip is nearly straight, as is usual with all species of this genus, and which feature distinguishes its shells from those of Campeloma, in which the outer lip is sinuous. Inner lip somewhat thickened by callus and reflexed at the proximal or anterior end, but not covering the umbilical fissure there, which is moderately large. ‘The precise shape of the aperture is unknown, but it is probably subovate. No entirely perfect examples have been discovered, but the largest one yet obtained would, if perfect, measure about 65 millimeters in length; full width of body volution, 38 millimeters. This species is deseribed by Meek, from an imperfect example, in U.S. Geol. Sur. 40th Parallel (King), vol. iv, p. 181, and figured on plate xvii, fig. 15, of the same volume; but it was not specifically named by him. He referred it to the genus Campeloma, but the numerous specimens that have been obtained from the same and other localities, as well as his own type specimen, show that the species possesses the true characters of Viviparus. It is distinguished from all other species of the genus known to me in American strata by its great size, and there are few other. forms with which it is in any danger of being confounded. From YV. puludineformis Hall it differs in its more robust form, inthe greater con- vexity of its volutions and the abrupt rounding of their distal side, and in the presence of a distinet umbilical fissure. Position and locality —Laramie Group, valley of Bear River, seven miles northward from Evanston, Wyo., and also near the mouth of Sulphur Creek, above Evanston. It is associated with other fresh-water forms, and also with many of the characteristic brackish-water species of that series. 100 GEOLOGICAL SURVEY OF TIE TERRITORIES. VIVIPARUS LEAI Meek & Hayden. VIVIPARUS RETUSUS M. & H. VIVIPARUS PECULIARIS M. & H. VIVIPARUS TRUCHIFORMIS M. & H. VIVIPARUS REYNOLDSIANUS M. & H. VIVIPARUS LEIDYI M. & H. The types of the above-named six species were collected by Dr. Hay- den from the Fort Union series of the Laramie Group, in the Upper Missouri River region; they are described in vol. ix, U. S. Geol. Sur. Terr. (4to ser.), pages 577-582, and figured on plate 44 of the same vol- ume, except the third, of which there is a wood-cut accompanying the description. I think one cannot study these forms of Viviparus without becoming impressed with the belief that they are all genetically related. Indeed, it seems probable that further study of large collections of them will show that not more than two species ought to be made out of these six forms, even with the ordinary methods of discriminating study of fossil mol- lusca. From several localities in Utah examples of Viviparus have been brought in by different parties, some of which closely resemble the fourth, fifth, and sixth of the foregoing forms respectively. They are from strata that probably really belong to the Laramie Group, and are also probably related genetically with those forms. VIVIPARUS CONRADI Meek & Hayden. This form was obtained by Dr. Hayden from the Judith River series of the Laramie Group, where alone it has yet been discovered; but Mr. Meek thought it probable that V. peculiaris of the Fort Union series is only a variety of it. It is described and figured in vol. ix, U. 8. Geol. Sur. Terr. (4to ser.), p. 879, plate 42, figs. 15 a, b, c, and d. . Genus TULOTOMA Haldeman. TULOTOMA THOMPSONI White. Plate 28, figs. 2 a, b, ¢, d, e, f, g, and h. Tulotoma thompsoni White, 1876, Powell’s Rep. Geol. Uinta Mts., p. 134. Shell moderately large, having somewhat the general aspect of T. magnifica, the type of this genus; spire elevated, its sides having a broad general convexity, and the apex being somewhat blunt; volutions six or seven, their outer side flattened or slightly convex; proximal side of the last volution also flattened or slightly convex, producing a more or less prominent revolving angle between the proximal and outer sides of the last volution, but wiich is obscured in the spire by mutual contact of the yolutions. there; suture linear, or faintly impressed; umbilical perforation apparently wholly wanting in all cases. Surface of the three or four smaller volutions of the spire marked only by lines of growih and a few revolving lines, two of which are sometimes in the form of slight angulations; but the last two or three volutions are usualiy con- spicuously marked by prominent tubercles, which are arranged in two or three revolving rows, which extend to the aperture, and which are usually connected together in their respective rows by raised revolving lines. The distal row of tubercles on each volution is stronger than WHITE. ] LARAMIE FOSSILS. 101 either of the others, and the tubercles of this row are, when of full size, elongated, not in the direction of the row, but their axes are a little oblique to it. The proximal row (not the one which sometimes appears on the flattened proximal side of the last volution, but which is usually absent) is directly upon the angulation which is formed by the meeting of the flattened proximal and the outer sides of the volutions. 'There is sometimes another row of tubercles between these two, but it is often absent or reduced to only an obscure raised line. Sometimes the tuber- cles are so strong as to give the shell a conspicuously rugged appearance, but other examples are so slightly marked in this respect as to appear much like specimens of true Viviparus. Such examples very closely resemble V. trochiformis Meek & Hayden, as may be seen by comparing figures of that form with figure 2 g on plate 28. Indeed, notwithstand- ing the accepted generic differences between them, the two forms are probably genetically related. If so, one of the forms has gained a gen- eric characteristic without losing all its specific ones. It should be re- marked, however, that the operculum of this species has not yet been discovered. ‘This organ is quite characteristic in living forms of Tulo- toma, and without a knowledge of it in the case of the fossil form we cannot be positively certain that it is generically separable from Vivi- parus. Length of a large example, 38 millimeters; diameter of the last volu- tion, 25 millimeters. This species resembles the recent species T. magnifica Conrad, but it differs from that form in its less convex volutions, its faintly-impressed suture, and the different arrangement of its tubercles. It is the only known species of Yulotoma in American strata, but among European forms it may be compared with 7. ( Viviparus) strossmayerana Pilar. Judging from Brusina’s figures of that species, however, it differs in the less convexity of its volutions, especially that of the proximal side, and in the different character and position of the tubercles that mark its. surface. The specific name is given in honor of Prof. A. H. Thompson, formerly geographer of the United States Survey of the Rocky Mountain Region. Position and locality—Laramie strata, near the top of the group, at Black Buttes Station, Union Pacific Railroad, Wyoming, and also in the valley of Crow Creek, east of the Rocky Mountains in Colorado. Genus CAMPELOMA Rafinesque. CAMPELOMA VETULA Meek & Hayden. CAMPELOMA MULTISTRIATA M. & H. CAMPELOMA MULTILINEATA M. & H. Dr. Hayden obtained the types of these three species from the Laramie strata of the Upper Missouri River region. They are described and fig- ured in vol. ix, U.S. Geol. Sur. Terr. (4to ser.). The first two forms have also been discovered in the Bitter Creek series west of the Rocky Mount- ains, and the third one in the Laramie strata, east of those mountains in Colorado. The latter examples are represented by figs.4 a and b, plate 28. The examples show a more distinct shouldering of the distal border of the last volution than is shown by Meek’s figured type; and some ex- amples brought by Mr. J. A. Allen from the valley of the Yellowstone ae still more robust and show a still more distinct shouldering of that order. 102 GEOLOGICAL SURVEY OF THE TERRITORIES. CAMPELOMA MACROSPIRA Meek. Plate 30, fig. 2 a. Mr. Meek describes this species in vol. iv, U.S. Geol. Sur. 40th Paral- lel (King), p. 179, and gives imperfect figures of it on plate xvii of that volume. It was originally described by Meek in the annual report of this survey for 1872, and fig. 2 a, plate 24, is drawn from the type from which he drew that description. Some other examples, collected from the same locality which furnished the types, indicate a much larger size than even the figure on plate 24. It has been found only in the Bear River series of Bear River Valley, Southwestern Wyoming. Genus VALVATA Miiller. VALVATA SUBUMBILICATA Meek & Hayden. VALVATA PARVULA M. and H. Dr. Hayden’s collections from the Fort Union series of the Laramie Group in the Upper Missouri River region contain the types of both these forms. They are described in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), pages 290 and 291, respectively. The former is figured on plate 43, but the latter is not illustrated. Mr. Meek expressed the belief that it is only a variety of the first. VALVATA? MONTANAENSIS Meek. Mr. Meek describes this form from the Judith River series, Upper Missouri River region, in vol. ix, U.S. Geol. Sur. Terr. (4to ser.), p. 591, and gives three wood-cuts of it in connection with the description. It has not been discovered elsewhere in any part of the Laramie Group. Genus ODONTOBASIS Meek. ODONTOBASIS BUCCINOIDES White. Plate 20, figs. 3a and b. Odontobasis buccinoides White, 1376, Powell’s Rep. Geol. Uinta Mts., p. 124. Shell of medium size, somewhat robust; volutions six or seven, regu- larly convex; suture faintly impressed; surface marked by somewhat ' strong longitudinal folds or varices which end at the suture upon the proximal side of the volutions of the spire, but do not quite reach the suture upon the distal side, and upon the last volution they become ob- solete before reaching the anterior end of the shell; the whole surface is also marked by somewhat coarse revolving raised lines, which, in crossing the longitudinal varices, give them a crenulated appearance. The revolving lines which traverse a narrow space upon the proximal side of the suture, and also the space in front of the revolving furrow of the columella, are finer than the others. Odontoid process of the base not very prominent, forming a small angular projection at the end of the revolving furrow of the columella. Length, 37 millimeters ; diameter of the last volution, 22 millimeters ; but these proportions vary considerably in different examples, as is shown by the two figures on plate 20. WHITE. ] LARAMIE FOSSILS. 103 This is one of the few forms found in the strata of the Laramie Group, the only known closely-allied species to which are associated with marine species only. Its immediate associates are Ostrea and Anomia in abundance, and a few imperfect examples of Melania ? insculpta. Of itself, this species is suggestive of a marine habitat, but it is probable that, like the Nuculana and Awinea described in this article, it survived, without generic change, in thé freshening waters of the Laramie period. This supposi- tion is not at all an improbable one, as there is sufficient evidence, aside from the presence of these shells themselves, that the water in which they lived was in a considerable degree saline. Position and locality Bitter Creek series of the Laramie Group, two miles west of the Point of Rocks Station, Union Pacific Railroad, Wyo- ming. ODONTOBASIS? FORMOSA White. Plate 28, fig. 7a. Goniobasis? formosa White, 1878, Bull. U. 8. Geol. Sur. Terr., vol. iv, p. 718. Shell rather small; spire equal to about one-half the entire length; volutions about six; the last one inflated, and those of the spire moder- ately convex; the distal part of each volution somewhat shouldered, and marked at that part by numerous small longitudinal varices that be- come obsolete towards the’ proximal part of the last volution; these yarices are not more distinct upon the body volution than upon those of the spire; upon the latter spire there is also a small revolving fur- row near to and upon the distal side of the suture, giving those volu- tions a slightly constricted aspect, but which furrow seems not to extend to the body volution. Surface marked only by lines of growth, with the exceptions already mentioned, and that of some faint revolving lines upon the proximal side of the body volution, near the columella. Length, 12 millimeters; breadth of body volution, 7 millimeters. Only one example of this species has been found, and this is a some- what distorted natural cast, from the reddish shales of the Laramie Group, near its base. Neither the aperture nor the extremity of the beak is shown in the specimen, and I am not entirely satisfied that it belongs to the genus Odontobasis. It plainly does not belong to any described form, and it has the general aspect of a marine shell. I there- fore refer it, provisionally, to that genus, because it approaches it more nearly in its characteristics than any other known genus which is likely to exist in the Laramie Group. With this view of its affinities it is interesting as adding another form to those found in the Laramie Group, ° which are regarded as marine types. Position and locality—Laramie Group, about 400 feet above its base, Danforth Hills, near White River Indian Agency, Northwestern Colorado. cia vai. Ad [ta Seen ERE PES fs) OMS ol tl ale eae zea Auehase i RATA - Pate hae a “i if { is iM! epeeyes anit: he i 7 : test an ! fi ¥ iy CS ee tg bs ee ee : UCETe Lats aa aL Ai mH : a ise Nees ah o * | Grays fr SALE q i fri} ro hee, ey: Ried bey y sat at ue ree ini 2 Rey ie a 5 » Ore vAfaviae Pyle TH te ae “ii és) BMbvretbel talon ae , Ch & ae i Ah yets ier wets ule lhe td SFAEPER ELAR a Ha “ee set woofs’ AN, Ao aris ee Ba een ea 2. Bis. a ee ; Ms ee tesa 3 a ri iinet WEG Whe litt: On len OEHARE TE? phy gs ae like? a Daayft Th PSE stk Away petted reo Gey ey aan ae Hs y Te Aree T -< ee is Ms i . ; Tunes Stieber aE ARE a ae hw ; “a ar a a Vien ‘i Abel ; oat 4 Bah 2 Ay aes ie Pel 4 as Fic. Fic. Fic. FIG. 1. we 3 4, PLATE 20. OSTREA WYOMINGENSIS .. -. -- ----2--- e220 + eee cee cece oe ence cree see cee a. Lower valve; interior view ; natural size. b. Upper valve ; exterior view; natural size. c. Interior view of the same, showing hinge, pedal museular scar, and area. AXINZZA HOLMESIANA .-.-.-------------- sie slel Selec ereeeiseee eee sya a. Exterior view; natural size. b. Interior view of the same, showing part of hinge and area. ODONTOBASIS BUCCINOIDES ....-- Eisieia Hiaiavap le Sean eee teres See aes a. Side view of an imperfeet example; natural size. b. Similar view of another example, showing a variation of form. MIntANTA? SINSCULPTAG dsb a)e cece ee cece cesar ee eee eee a. Side view of a fragment, which is one of Mr. Meek’s types; natural size. Page. 56 102 94 LARAMIE. U.S.GEOLOGICAL SURVEY. PLATE 20 J.C.MS Connell onnell del. Yhos Sinclair’ Son, Lith: PLATE 21. Page. BIG OSTR BAN TNS CU RTS 52) ee eS Se Ve eee ce ag a a es a 56 a. Lower valve ; exterior view; natural size. b. Interior view of the same. Fic. 2. CORBICULA (LEPTESTHES) PLANUMBONA.-..-..----.----- see diahate oa 4 rue a. Right side view of an adult example; natural size. b. Dorsal view of the same. e. Right side view of another example. d. Lett side view of a large example. HIG. 3. CORBICULA OCCIDENTALIS... 2.005.425 oases ones aes ine che aie anu ea ris) a. Right side view of an example from Yampa Valley, Northwesteru Colorado; natural size. b. Right side view of Mr. Meek’s type of C. bannisteri. c. Dorsal view of the same. Fig. 4. CORBICULA CYTHERIFORMIS ......---.-- PAE AVES Guan eve Red NIUE RO AE 74 a. Right side view ; *natural size. b. Dorsal view of the same example. e. Interier view of a right valve. d. Interior view of a left valve. . CORBICULA (LEPTESTHES) FRACTA ......-- PREM Seagate neces RON US AAs cas ys 75 a. Left side view of an imperfect example, showing an unusually elongate form. 2! For other examples see plate 23. Fig. On Fig. 6. NERITINA VOLVILINEATA......--------.--- Psy ANOS Pamir cantl DIGI CaS A LS 2 8 88 a. Lateral view ; enlarged to ene and a half diameters. b. Apertural view of the same. U S.GEOLOGICAL SURVEY LARAMIE. PLATE 2, FD. Owen & J CM Connell del. Thos. Sinclair’& Son, Lith PLATE 22. ERAT Gaye VEER SS Al STEN TEN S20 I Ia Irae MUNG ey Ma a ae antaretate eta SOUBHAe a. Side view of a fragment, the type specimen; natural size. Fie. 2. UNIO BRACHYOPISTHUS..--2.2.-.-.-2-.5.---4- Eee AONE AAR ANID ste es a, a. Ixterior view, right valve; natural size; but this example is not fully adult. b. Posterior view of the same; the valve having been a little dis- torted by pressure. EOS UENO PTR O ASV Se eee a ps Van ek a8 Bl Mea ne ae ese acerca eee a. Left valve; natural size. b. Right valve of another example. ce. Front view of another example. d. Taterior view of a left valve. Fig. 4. UNIO HOLMESIANUS ....-...-2.. .---e Cy UNS FL Seen PN EE ED SAS a. Left side view; natural size. b. Dorsal view of the same exainple. e. Left side view of a young example, d. Front view of the same. e. Posterior view of the same. Page. 84 U.S.GEOLOGICAL SURVEY. WH.Holmes Del LARAMIE. RIL 22 Thos: Sinclair:& Son, Lith Ne PLATE 23. Fic. 1. CoRBICULA CLEBURNI...... 4-26. .-ccce fi Re LO ea c/a eC OG a a. Interior view, right valve; natural size. b. Exterior view of the same. c. Exterior view of another example. All of natural size; but the species reaches a larger size than any of those figured. Fic. 2. CORBICULA (LEPTESTHES) FRACTA..---..--. Usa Ge ae oO Sa a. From a drawing by Mr. Meek of an example from Hallville. b. Example from Black Buttes Station; left side view ; natural size. ce. Dorsal view of the same. d. Right side view of a young example; from the same locality. e. Dorsal view of the same. For another figure of this species see plate 21. Fic. 3. CORBICULA OBESA....-.....- SCN S18 HL Ne PR Ge SUA We ce I A . Left side view of an example rather above the average size. . Dorsal view of the same. Right side view of another example. . Front view of the same. . Dorsal view of the same. All of natural size. eaecs Fic. 4. CoBRICULA (LEPTESTHES) MACROPISTHA ..---....---.---- ndco boon so60 a. Left side view; natural size. b. Dorsal view of the same. e. Left side view of another example. d. Dorsal view of the same. e. Interior view of left valve. Jf. Interior view of the right valve of another, a larger, example. =I OU LARAMIE. U S.GEOLOGICAL SURVEY F.D. Owen & WH Holmes del Tuos. Sinclair-& Son, Lith En ue » PLATE 24. Page. Gael UNTO CR VP TOREWN CHUS eee reece slaseaee ater cere Sele meioe Sie 68 a, Exterior view, right valve, of 1 broken example; natural size. b. Interior view of the same, showing the hinge. Fig. 2. ANODONTA PROPATORIS ......--- ANBAR e HS MoO oro mrnecaoosTodcds 61 a. Left side view of a natural cast of the interior; natural size. b. Left side view of a young example. ce. Dorsal view of the same. d. Fragment of left valve, showing the hinge. Fig. 3. ANODONTA PARALLELA ..---...-..- Delete wens asta None eel o saa aay 62 a. Restoration figure from fragments of right valves; natural size. Hen 4) (PHYSAY COPED. 6252 2.00 a UT UN eae ec a. Side view; natural size; the outer labial portion restored. b. Apertural view of the same. BiGs 05 -DULINUS ATAVUS {lis oS ea ae iray alates een aseyere per eiereie RSs is seean A 86 a. Side view; natural size. b. Apertural view of the same. HIG NG: YBULENUS DISJUNCLUSsoaceeisese asec eee eciee e eee oe Eee ee eenee 86 a. Side view; natural size; showing the disjoined and flexed portion of the inner lip. b. Apertural view of the same. US. GEOLOGICAL SURVEY. LARAMIE. Sara WH.Holmes & FD Owen Del Thos binclair-& Son, Lith PLATE 25. Page. Fig. 1. ANOMIA GRYPHORHYNCHUS ..---- Meiers aiafate sycleveiaioners salcisioeesen oe unter 57 a. Exterior view of an upper valve; natural size. b. Lateral view of the same. c. Exterior view of two examples; upper valves. » Fig. 2. ANOMIA MICRONEMA .---- 2 bieldiat Sie) a/sih lS otc NV aay pO RET as eee ee ay 57 a, Exterior view of an upper valve, showing the radiating lines of the usual character; natural size. b. Another example, showing coarser lines. e. Another, larger, example, upon which the radiating lines are obso- lete or absent. d. Interior view of another example, showing the process beneath the beak for the attachment of muscles. All upper valves. JOG, By WOM IBIEAN (ERY ACiara DONNA) IRIXGRODE/SHS) Sod ooo ob ocod Seen enosance sacoce 58 a. Right valve; natural size. Fig. 4. VOLSELLA (BRACHYDONTES) LATICOSTATA. ---.-- UN Mh aes a INA ass 59 a. Right valve; natural size. Pic. 5. CORBICULA CARDINIZNORMIS..--.------.-.-- area Wis BS ER eae I ie a. Left side view; natural size. b. Dorsal view of the same. KE, Gy CORBGGUON SOIC ONMENS so2555 cososcdcouses Bist LILY SLs te NE See 80 a. Left side view of an example from Crow Creek, Northern Colorado. band c. Left and dorsal views of another example from the same locality. d. Meek’s type of C. crassatelliformis, from Hallville. eand f. Different views of two of Meek’s types of C. tropidophore ; from near Point of Rocks Station, Wyo. LARAMIE. U.S.GEOLOGICAL SURVEY WANS tae Thos. Sinclair’& Son, Lith Hs pi es ee yee otis Nii by rey bi, iy Veale TU Sain 9 PLATE 26. Fig. 1. UNIO ENDLICHI a. Right valve of large example; exterior view ; natural size. b. Interior view of a smaller left valve. Fic. 2. UNIO GONIONOTUS a. Right side view; natural size. b. Front view of the same example. c. Lett side view of a young example; natura! size, d. Right side view of the same. e. Dorsal view of the same. US. .GESLOGICAL SURVEY. = UIA PLATE 26. Thos. Sinclair-& Son, Lith. ri) / fate ANTE a é 4 PLATE 27. NGS Lip Ops) COAST G56 Goch doko aeoe he sa55 Hooeno cedouodocdasGo06se goscco cone a. Left valve; natural size. Fig. 2. UNIO DANA? a. Exterior view ; right valve; natural size. b. Interior view of a left valve. Both examples are from Black Buttes Station, Wyo. Fic. 3. CASSIOPELLA TURRICULA a, b,c,and d. Lateral views of different examples; natural size. eand f. Two examples, showing the aperture and small umbilicus. g. Basal view of anotherexample, showing the umbilicus, the diameter of which is proportionately a little larger than the average. US.GEOLOGICAL SURVEY ; TEESE SMO : IPILANH 27% Bg ee a car Re WH.Holmes & F D Owen Del. Thos. Sinclair’& Son, [ith- ; ¥) a Resa Fig. 1. Fic. 2. Fic. 3. Fig. 4. Fie. 5. Fic. 6. PLATE 28. WNIOISHNHNCIUS= rere ceoaeseee bee RS ea be ere eee aioe & a. Right valve; natural size. b. Anterior portion of a left valve. c. Interior view of the same. TULOTOMA, THOMPSOND. 2 530 5)54 Gass oo ae oe sicinle een eerete eee uate reicisile a. Lateral view of an example from Black Buttes Station, Wyo. ; natural size. b,c, d,e,f, and g. Examples from Crow Creek, Colorado, showing a wide range of variation in surface features. h. Basal view of another example, showing the character of the inner lip. VIVEPARUS PLICAPRESSUS ase Secs oo ae ee Sees TMs os eas a. Lateral view; natural size. b. Similar view of another example. CON BEIMO N.C WA IROCNOC ANDOU ERGs Sooo Sosa geee cosas cee ccc 6225 sce aeee a. Side view of an example from Crow Creek, Colorado; natural size. b. Another, more robust example, from the same locality. VIVIPARUS PRUDENTIUS ..-----------.------- oeidele es Ieee aed ares a. Side view ; natural size. b. Apertural view of the same. MPTANTA: WYOMINGENSISE easiest a ieieiyenen = sane te sersesanele =e eeieereers ie a. Side view of a large example, showing the five last volutions; natural size. b. Another example, showing some of the distal volutions of the spire and the beginning of the revolving row of tubercles. Page. 69 100 201 98 SES LARAMIE. At U.S.GEOLOGICAL SURVEY. PLATE 28. rio) YY we & Se ~ E 5 Thos, Sinclair -& Son, Lith, P.D. Owen & J CMe Connell del yay Ah BU PLATE 29. FIGHT UINTO: GONEAMBONADUS 2 coals 252 Saas arse ree ata eel sta) ate Ace e hase a. Left side view; natural size. b. Dorsal view of the same exaniple. These figures are partial restorations as to form, the example hay- ing been somewhat distorted by accidental pressure. HIGA2) WINEO AED RICHIE Joos SSE UN Ee i ae et ee a. Left side view; natural size. b. Dorsal view of the same.. Fic. 3. UNIO PRIMZVUS worm es pee ees eee eee eee eee eee eee ete ees ec cecs C2 oces Coee = a. Left side view of a small example. b. Interior view of another example ; both snevnem! Size. BGs 4 CORBUUAs UND ERE RA cays ee ay Lb een a je pneu Nas 5 eoce cee eee ee ee scoe a. Right side view of a large example ; natural size. b. Dorsal view of the same. e. Left side view of a smaller example. d. Front view of the same. eand f. Side and front views of a young example, showing the man- ner ef formation of the first of the larger concentric valves or folds. Fic. 5. CORBULA UNDIFERA var. SUBUNDITERA ...... ---- Spa Tat AME Og a le a. Right side view; natural size. b. Lett view of the same. c. Dorsal view of the same. Fic. 6. NERITENA (VELATELLA) BAPTISTA ...-..------------+--e2- pdocke cae bc a. Dorsal view ; enlarged to one and a half diameters. b. Lateral view of the same. LARAMIE. U’S.GEOLOGICAL SURVEY. ; REAE 2a F.D. Owen & J.C. Mt Connell del. Thos, Sinclair & Son, Lith. Pa CL e Lael cy st ARC are) eg TANGLES te Naediceaia att! i Nad 4 i HERS ; aaa eae oF he . Ma h Fig. 1. Fic. 2. Fig. 3. Fic. 4. Fic. 5. Fig. 6. Fig. 7. Fic. &. Fie. 9. Fic. 10. Fie. 11. PLATE 30. VIVIPARUS COUESI ..---- ---- + - +--+ 2-2-2 ene ee cece ene cece cece eee a. Side view of the largest example discovered; natural size. The apex above the three last whorls has been restored from another example. CAMPELOMA MACROSPIRA...--- .--2----0+ ---- --0- ---- ---+ ---- --2----- a. Side view, natural size, of Mr. Meek’s type specimen. INERITIN AGN ATICINOR MIS os salsaeeitsiee aise eer eetsaetete a eleteleiaalalanatetlaner a. Side view ; enlarged to four diameters. b. Apertural View of the same. These figures are not very satisfac- tory. GONIOBASIS| CLEBURNI-sesiscme eerie eeieseeecinsec ne cieeeaieer aeeelsseterat a. Side view of an averaged sized example ; natural size. b. Apertural view of the same. ec. Side view of another example. d. Fragment of a large example. GONIOBASIS CHR YSALLONDE Aw een ee oe ee eee cele eeieieeine neletatecisetisisne ets a. Side view of an imperfect example ; notre size. b. Similar view of another example. GONIOBASIS (CHRYSALLIS2 oo). c-nelscwieenicmeises sissy seen eyecare ete a. Side view; enlarged to two diameters. b. Similar view, of another example, the spire of which is naturally or otherwise bent. GONIOBASIS ENDLICHI .-...-- een ee eI oI a PS Mae MUTA Malis og oN a. Side view of an imperfect example, showing the revolving lines very distinctly. b. Similar view of another example, showing the lines less distinctly. ec. Apertural view of another example, from which the lines have been removed by attrition. All of natural size. RY TOPHORUS MERKLE = cece neeemcc eerie eee SES eats Re HS Inet ye: a. Side view ; natural size. b. Apertural view of another less perfect example. ACELLA HALDEMANI .......-----.---- B SMO EO Seo ba CHOH donc acoEsolodoa.s a. Side view; enlarged to four diameters. b. Apertural view of the same. GONIOBASTS MUA CIERRA 2 cc)oig 2s Sue yale ey 2) he oe ch a a. Side view ; enlarged to one and a half diameters. PHYSA a. Side view ; natural size. eee - - -g66ed sodeds d4c6s5 S40005 S540 Sood o46o80 sod4.6855 102 89 91 92 91 92 82 93 LARAMIE, eth U.S.GEOLOGICGAL SURVEY lA EO TSS | slair'& Son, Lith, F.D. Owen & J C Mf Conrell del CONTRIBUTIONS TO INVERTEBRATE PALEONTOLOGY NO. 5: TRIASSIC FOSSILS OF SOUTHEASTERN IDAHO. By C. A. WHITE, M. D. The fossils discussed and illustrated in this paper are those which were under the designation of TIossils of the Jura-Trias, described in the Bulletin of this survey, vol. v, pp. 105-117; having all been col- lected by Dr. A. C. Peale, assisted in part by Mr. J. EH. Mashbach, in 1877. ‘The fossils in question were obtained in Southeastern Idaho; and a part of the species, especially the Cephalopods, have been found at no other than the localities which furnished the type specimens. A part of the Conchifers, however, had been previously found by Dr. Peale at other localities, not many miles distant, in Southeastern Idaho and the adjacent portion of Wyoming; and one of the species, Aviculo- pecten idahoensis, had been described by Mr. Meek. The strata of the localities last referred to had been by common consent assigned to the Jurassic period by the geologists who had visited them; or, ‘latterly, to the Jura-Trias, in consequence of the growing opinion that no paleonto- logical plane of demarkation exists between those series of strata which have hitherto been assigned respectively to the Jurassic and Triassic periods. I had adopted this latter view for the reason indicated, and in the first publication of these fossils I referred them to the Jura-Trias. The distinct Triassic character of this small fauna, however, as well as that of the one previously discovered in Nevada and California by King and Whitney respectively, seems to warrant the entire separation of the strata containing those foun from the Jurassic, and their reference to the Triassic. This view finds support also in Dr. Peale’s observations concerning the position of the strata from which he obtained these fossils, in relation to those which contain the undisputed Jurassic fossils above, and the Carboniferous strata beneath. I have, therefore, in the title of this article, referred the fossils of which it treats to the Triassic period. Among the species which are generally regarded as characteristic of the true Jurassic strata of the West are Pentremites asteriscus, Belemnites den- sus and Camptonects bullistriatus of Meek & Hayden, and Humicrotis curta Hall; and these species were obtained from some localities in the region within which the fossils of this article were obtained; but not from the same strata, with the apparent exception of EL. curta. Indeed the fauna of the strata which bear the fossils discussed in this article is quite dis- tinct from any other known in that great region, and, according to the observations of Dr. Peale, they occupy a distinct horizon much lower than that of the characteristic Jurassic fossils before mentioned. He places this horizon beneath the Red Beds, or the formerly accepted Triassic, and above the Carboniferous. The foiiowing remarks are based minainly upon his observations. Anong the exposures of Triassic strata in Southwestern Idaho and 105 106 GEOLOGICAL SURVEY OF THE TERRITORIES. the district immediately adjacent (and they are numerous and compar- atively small in consequence of the great disturbance which they, to- gether with their associated strata, have suffered) there are three local- ties which are especially interesting because the strata there exposed not only contain anumber of specific and generic forms not hitherto known, at least not certainly known, in America as regards the latter, but be- cause some of the types in which those forms are expressed are such as im Kurope are regarded as characteristic of the Middle Trias. For con- venience of reference these localities are designated as Nos. 1, 2, and 3. Locality No. 1 is within the limits of Idaho, about sixty-five miles north of the boundary line between that Territory and Utah, about eighteen miles west of the boundary line between Idaho and Wyoming, and about five miles west of John Gray’s lake. The lata for the following section at that locality have been furnished by Dr. Peale, who has also treated this subject at some length in the Bulletin of this survey, vol. v, pp. 119-123. Section at locality No. 1. arenaceous shales. Ontcrops obscure. The following fossils were obtained from near the top of this member: Terebratula semisim- plex White; T. augusta Hall & Whitfield?; Aviculopecten idahoensis + 1,00 feet. Meek; Gervillia —— ? and an undetermined conchifer.....-...- B.—Limestones; outcrops somewhat obscure. The fossils are Humicrotis curia and Aviculopecten idahoensis2. +220 s22cs2 e225 jeeeees eesee- =. C.—Greenish and reddish fossiliferous sandstones, followed by arenaceous shales and limestones. The fossils are Aviculopecten pealei White, > 850 feet. and three or four undetermined species of conchifers.......-...-.- D.—Bluish-gray limestones, with fossils near their base. The fossils are) . Meekoceras gracilitatis White; M. mushbachanum W.; Arcestes? cirra- 700 feet A.—Uppermost member of the local series; alternating limestones se] tus W.; Arcestes? ————?; Arcestes? (anotherspecies) and Eumicro- tis! curta: Tallies. 253th sels ee eee an ape ede ave ha NS oa E.—Reddish and greenish laminated sandstones....-.-.----- Bo Cee en HeeS 400 feet. if —— Very dark-bluesandstoneiass so. se aeee eee ee eee cee ee eee eeees -- 200 feet Gi— Wihite quartzite: 2 sc.ciie cea ee econ en peer ta ie sors er are etrcte crete elas te : H.—Base of local series ; massive grayish-blue limestone. ..---..-----.--- 400 feet. The strata of this locality have been much displaced, the dip being to the southwestward, and at an angle of about 55°. At the southern por- tion of the exposures of the strata of this locality, however, the strike curves to the eastward, so that the dip is there to the southward, and the angle lessened. At locality No. 2, which is about fifteen miles a little east of south from locality No. 1, occurs another limited exposure of limestonestrata, which are equivalent in part with those of locality No. 1, and which there occupy a synclinal axis. From these strata Meekoceras aplanatum and M. gra- cilitatis were obtained. The presence there of the latter species seems to sufficiently indicate the equivalency of those strata with member D. of the foregoing section at locality No.1, because numerous examples of _ that species were obtained from that member of the section referred to: About the same distance as before (fifteen miles), almost due west from locality No. 1, is locality No. 3, the strata there being calcareous sandstones. From these strata Dr. Peale obtained Aviculopecten ida- hoensis Meek, and A. altus White, examples of the former species being somewhat abundant and the latterrare. A. idahoensis also occurs in both A and B of the foregoing section, with which members of that section the strata of locality No. 3 are doubtless equivalent. Mr. Meek’s types of this species, which he referred to the Jurassic period, were obtained several years ago by Dr. Peale in Lincoln Valley, near Fort Hall, about fifty miles northwestward from locality No.1. So far as I am aware no other species were found associated with it there, and it has been found atno wuire.] TRIASSIC FOSSILS. 107 other localities than those herein mentioned. It is reasonable therefore to regard it as peculiar to the horizon which furnishes the Cephalopods and other fossils pertaining to the peculiar fauna discussed in this article. The following section is copied from Dr. Peale’s article in the bulletin of this survey before mentioned, and is introduced here for the purpose of showing his views of the geology of the district in question after the very brief examination which he gave it in the autumn of 1877. General section of the Jura-Trias in Southeastern /daho and Western Wyoming. a (2) iS aa] & | 5. Red and gray shales, with green sandstones and irregular greenish arenaceous 5 limestones at top. Thickness, 700 fees. =I S| 8 = & yi ae |e i) Fa 4 | 4. Laminated liméstones, blue at base, passing into gray at top, succeeded above Zi by grayish, calearcous shales; many of the layers are probably arenaceous. OD & Thickness, 800 feet. 4 5 , : ia fal q a i=) a 3 & | 3. Red quartzitic sandstones with shaly arenaceous and calcareous layers at the A base of the section. ‘These are probably the equivalent of the typical ‘‘ Red a Beds” of the Eastern Rocky Mountains. Thickness, 1,000 + feet. FS 2 Alternations of reddish and greenish sandstones, and arcnaceous and calcareous shales, with blue and gray limestones; generally laminated. Thickness, 1,009 + feet. 1 B | 3 | i | oa a nS 1. Massive grayish-blue limestone, overlaid by quartzite and dark-blue laminated z limestone. Thickness, 1,000 + feet. - Cr) i fa ef 9 Nos. 1 and 2 of the foregoing section embrace the same strata which are represented by the previous section of locality No. 1. The fossiliferous strata of the three localities herein especially consid- ered contain all the new fossil forms which are described in this paper, together with the three following identified species, namely Terebratula 108 GEOLOGICAL SURVEY OF THE TERRITORIES. augusta Hall & Whitfield, Aviculopecten idahoensis Meek, and Hunicrotis curta Hall. I am not entirely satisfied of the identity of the species here referred to 7. augusta, and there is a possibility that the Humicrotis is not HL. curta ; but so far as can be at present determined, it is identical. According to European standards the Cephalopods here described are unquestionably of Triassic types, and, as pointed out by Professor Hyatt in the following remarks, they have more resemblance to certain Ceph- alopods of the Muschelkalk or Middle Trias of Europe than to any other. The Triassic fauna discovered by King and Whitney respectively in Ne- vada and California was referred, and doubtless, correctly so, to the Upper Trias, and it was expected, in case a Triassic fauna should be found in the Rocky Mountain region, that it would also be referable to the Upper Trias. There was, however, apparently no special reason for such an opinion except that the evidence of the existence of any true Triassic fauna had so long escaped detection in North America, although the full series of strata had apparently been thoroughly examined at ‘hundreds of localities, and over a very wide area; and the Upper Trias fauna referred to was the only one then certainly known to exist in North America. The Cephalopods of this collection were placed in the hands of Prof. Alpheus Hyatt for examination, the results of which are included in the following pages. Three of these forms, together with certain other European species, Professor Hyatt regards as constituting a separate genus, to which he has applied the name Meekoceras. BRACHIOPODA. Genus THREBRATULA Llhwyd. TEREBRATULA SEMISIMPLEX White. Plate 31, figs. 3 a, b, and e. Terebratula semisimplex White, 1879, Bull. U. S. Geol. Sur. Terr., vol. v, p. 108. Shell small, obovate or subelliptical in marginal outline; width less than the length; cardinal slopes gently convex or faintly angular ; mar- gins of the shell obtuse; both valves somewhat regularly, and nearly equally convex; beak of ventral valve moderately prominent, with the usual curvature over that of the dorsal valve, and with the usual apical perforation. Sila Shell-structure minutely punctate. Surface of both valves marked by numerous small radiating plications, sometimes slightly irregular in . Size, with the intervening spaces about equal in width with the pli- cations. These plications never reach the beaks, and sometimes they are so faint, and extend so short a distance from the front margin that the shell appears almost plain. The surface is also marked by the usual lines of growth. ; Length, 14 millimeters ; breadth, 11 millimeters ; thickness, 9 millime- ers. The form, and more especially the plications, of this shell give it the appearance of certain forms of Rhynchonella, but its punctate structure forbids its reference to that genus. Perhaps it is really a Waldheimia ; but as the internal structure is not known, it is at present referred to the typical genus of the Terebratulidee. WHITE.] _ TRIASSIC FOSSILS. 109 Position and locality.—Triaxsic strata; member A of the section at locality No. 1, Southeastern Idaho, where it is associated with Seo) AS ae alee 2 ee dy a 108 a. Ventral view; enlarged to one and a half diameters. d. C. Dorsal view of the same. Lateral view of the same. U.S.GEOLOGICAL SURVEY. J. CME Connell del, TRIASSIC. UNS ill, Thos. Sinclair’& Son, Lith: PLATE 32. ENG? MuEnKOCrRAS IMUSHBACHANUM G22) S202 fi ene mie ne steel (eee eee a. Lateral view; natural size. b. Peripheral view of the same. c. Section of the same along the perpendicular line of fracture shown in Fig. 1 a. d. Septum of a large example, near the living-chamber. Gi 25 AVACULORE CLM N DAT ORNSIS oe oe eee se) eno OAM a. Left valve; natural size; from a natural cast in hard sandstone. PEG Ho VAVICULOPECTEN “ATTUS oso colo -< ll eeye ie nie rege epee a eu ee ea a. Left valve; natural size; from a natural cast in sandstone. HKG. 4p AVICULOPECTEN (PEALED 32.05 S550 0) SS) ae Dar eso a. Left valve; natural size; from a natural cast in sandstone. US.GEOLOGICAL SURVEY. TRIASSIC. PLATE 32. J CME Conneil del Thos, Sinclair:& Son, Lith r agi! A CONTRIBUTIONS TO INVERTEBRATE PALEONTOLOGY NO. 6: CERTAIN CARBONIFEROUS FOSSILS FROM THE WESTERN STATES AND TERRITORIES. By C. A. WHITE, M. D. Among the collections of fossils pertaining to this survey, and in part also to that which has hitherto been under the direction of Professor Powell, there are the types of a considerable number of invertebrate species, preliminary descriptions of which have from time to time been published by the late Mr. Meek and the writer of this article respect-_ ively, in certain of the publications of the two surveys; but none of which were illustrated before the commencement of this brief series of illustrated articles. A large proportion of the species referred to have already been. illustrated in the five first articles of this series, namely, Contributions to Inverte>rate Paleontology Nos. 1, 2, 3, 4, and 5, and the present article is devoted to the remainder. E.8°N. a. Archean b.Silurtan. c. Carboniferous. ad. Jura-Trias. e. Lararme eae. ft. Tertiary. WYOMING RANGE, NORTH OF HOBACK CANON. Hoback Carionkudge. Gros Ventre Mts. Siidke &Hobade = Las2Nn. - Gg. Quaternary SHCTION ACROSS THE WYOMING RANGE, THROUGH STATIONS VI,VIIL ann IX. —- ss ~~ & = Salt titver fet age. & a JSokn Day Ridge Hoback Caron kvdge. OM ETEOT AT AGEL. y Sta IX. : Sta. VIL. Hoback (Sta.VI ) PEAK Hoback S000f. 9 i iS - y Bustin 8 8s NS g : xe NS 22 22 S Z = a. Carbontrerows. eg POLE AD He See DEEL: 6. Triasstc. — > HAST. Cc. Jurassic. a. Larvarite, etc. e. Tertiary. tf) Quaternary SECTION ACROSS THE WYOMING RANGE, SOUTH OF HOBACK CANoN, AND PART OF THE SNAKE RIVER RANGE. Snake River Range. Oi) John Day hidge. 3 Ss Hoback Caution Fridge we MiBarrd ridge. N an Stee LV x 5.000 16. 3 & 5 x BS Sep ee N : 3 i! $ | ara é = St ‘SOUIvIOTY ‘AICIVIOT, 9 (j) otmrere'T Q ‘ieeqory 0 : ‘AOT[VA IOATY Moor roddy) TIAX ‘e189 “Sq Suyur0S (Sem) § “aS “SYN JOA PULM ‘oyeroM0[Sa00 Areiy.1ay, 9 “MIVIFAAL Q ‘ULeqoly v “TAX WOT}LCIS AYLULOT A, ‘LaTT@A TIAL Woodlt) JO o[YOld | VWO00 TAX “835 ‘SHIT JOATY pul TIX 971d st. JOHN.] VALLEY OF GREEN RIVER. 207 Ventre drainage. But the meager facts in our possession are not deemed sufficient to establish beyond question so intimate stratigraphical syn- chronism in the Tertiaries of the at present topographically distinct basin areas here alluded to. The Green River Valley, lying within this district, shows a broad ex- panse of level bottom-land and low terraces, giving place on either hand to gently undulating uplands, with here and there low hills and isolated buttes composed of horizontal Tertiary strata. Not till beyond our limits is the stream encroached upon by the uplands and accompanying bluffs, which to the south constitute so characteristic and interesting features in the geology and scenery of the valley. The river bottoms and terraces are both well defined, and if they are not entirely they are at least largely fashioned out of Quaternary deposits. The river gener- ally has a rapid flow over a broad, shallow, bowlder-paved bed. The intervales are often little better than spongy mosses, densely overgrown with willows; but the terraces are invariable gravel strewn, and beau- tiful examples of their kind. The whole country is well covered with bunch grass, and for grazing purposes it would seem to be eminently adapted. CHAPTER LV. GROS VENTRE RANGE. The Gros Ventre Mountains constitute a well defined range with a trend approximately ESE. and WNW., stretching from the foot of Jack- son’s Basin, east of the southern terminus of the Tétons, over to the Wind River range, nearly opposite the debouchure of Green River Cation. Hence, its longer axis is little more than 40 miles, with a transverse breadth of somewhat less distinctly marked limits ranging from 8 to 14 miles. The western end of the range was visited the previous season, an account of which, together with a general account of the range, was given in the report on the Téton district, United States Geological and Geographical Survey of the Territories, 1877. Notwithstanding the haste with which the present season’s explorations were conducted, it is be- lieved a sufficiency of data was secured by means of which a general un- derstanding of its geological structure may be arrived at. It is apparent that the present condition of the range does not pre- serve its original proportions; that in Pre-Cenozoic times it was sub- jected to erosive agents whose action has degraded and removed an enormous quantity of rock materials over its whole extent, but. espe- cially active were these degrading influences in the western portion of the uplift where half its original bulk has been swept away and the commi- nuted materials intermingled with the thouxands of feet thickness of Tertiary sediments filling “the neighboring basin areas. Although the vertical displacement varied considerably, being greatest in the west- ern half, erosion has reduced the crest of the range to a nearly uniform average height of 11,000 feet. The highest point, 12,200 feet, lies about 12 miles to the northwestward of Gros Ventre Peak; at Station XII in the western part of the range the altitude is 11,196 feet above the sea. For the better understanding of the account of detail geology given in the following pages, a brief summary of the general structural fea- tures of the range, such as they are understood to be, is here intro- duced. Although the trend of the range, topographically, is as above stated, ESE. and WNW., the axis of elevation lies more nearly in a SE. and NW. direction. The upheaval, which was evidently an event closely following the close of the Mesozoic age and probably extending into Cenozoic time, Was accompanied by at ‘least two principal mount- ain corrugations parallel with one another, and perhaps not more than 5 miles apart. Besides the principal folds there were other minor ENrinlations, whose extent and relations can only be worked out by a careful detail survey. The respective extent of the longer axis of the principal folds cannot at this time be determined, but the : amount of ver- tical displacement in the southern fold was at least a few hundred feet in excess of that in the northern one. In the eastern half of the range, however, the southern fold has been ‘entirely removed by erosion, so that the ‘south flank of the mountain in the latter quarter is formed by 208 IV, XLVI (1877) Si Gros Ventre Fv Vv % Gs ox (B77 | Gros Ventre Riv. I2Z.000 f I —— ae A ATCLLCEOUS.: ft Tertiary. ION XIL. Hobac Gros Ven fre Riv er: M4 oon e 12.000 a. fettcect.s. Sle A I hOUIN ZXOXLX. Hobu Cros Ventre Basin L2.000€ Le ey 9 hy ies His Ri 4 ey Ley \ AY Vy if, easieeae MMA MSM — ENE. a. Al cong lomerate. g- Moraines. re f oman = Sarena ee ey She ci Neat ran anes 1s hae iene eok GROS VENTRE RANGE: SECTION THROUGH STATIONS XILIV, XLVI (1877) : * Sta. XLVI (1277, Little Gros Wemene (ex (Meas Gros Ventre Rtv. Snake Fr Ste XLLV (1877) vs Vi \- (Base 60006 SBoe @ Archean. 6b. Stliriarn c. Carbontterous. a. Tura - Teas ©. Tertiary. GROS VENTRE RANGE : SHCTION BETWEEN STATIONS XI AND XITIV (1877) Snake River Valley: Sta.XT ridge Little Gras Ventre G: (IG CE - a als South Hold. North old. OTe 22.0007: “2 1 Miles ce (Base “60008. above sea ea te - a. Archcan. 6. Stlurtare c. Carboniserotts. ad. Jura -Trias. e. Getaceous. ft Tertiary. GROS VENTRE RANGE: SECTION THROUGH STATION XII. Hobackhidge. Central Plateanw. Gros Ven re kv er v WA 1.000%. ; iMite. ORR Key a a So ‘(Base 60001 aborv ya iaeeen a. Archcan. OO. Stlitr-vare, C. Carbontleroits. a. Jura-T pias. eC. Creticeotes. Oe: GROS VENTRE RANGE: SECTION ALONG A LINE WSW. FROM STATION XXIX. Hoback Canon krdge. South bold. North fold. : ; Hobuckh Bastie, Hoback drainage. Gros Ventre dramage. Cros Verrtre Basin 1 72.000%€. Vase C000. aba WE : z : 3 ENE. a. Archean. b. Silurian c. Carboniferous: a. Jura -Trias. e. Gretaceorts. Ty erttary,red conglomerate. Gg Moraines. Plate NII. Seal bei Riel ated athe rp S . ——= IF. GOIN atm CruUary YTRE PEAK. by 5 ‘entre Bastin. —_—- >» "EL10 °N. Tertiary. je be (SUA Xd ) Gros Verlre Rasir. XTX Sta. XXIX. Gros Ventre iv a. —> NE. onglomerate. AL Tertiary. [EO Ove eh iit vont SOLS id se aie oh it i mat ~ a et) Shy sume rege uy Nie us ANU yt He hip GROS VENTRE RANGE: SECTION EIGHT MILES N.W. OF GROS VENTRE PEAK. Hoback. Basin Cros Ventre Basia Moback drainage. iS 22.000 ft. ae ——— hile a a adreheaw b. Sihirian ce Carbortleroits. => -E 308N: a. Sura -Trias. e Cretaceous. lo Terttary GROS VENTRE RANGE: SHCTION FIVE MILES N.W. OF GROS VENTRE PEAK. Hoback. Pastre Lf orks Hoback: Le. 2. 000T€. Gras Ventre Basin. > : > “fo > s— x KE 10°N. a. drchear . Stleercar » Carborntreroies Bo GE SGP IEO PUERTO GROS VENTRE RANGE: SECTION THROUGH GROS VENTRE PHAK (STA. XII) Hoback Basti, Sta XM. Gros Verte Bastin. Hoback. iver . x Oreen River drainage 12.0004. PN itarceneen, Bae es ae a Arch cea 6. Stliurtor c. Carboniferous. ad. Jura- Trias GROS VENTRE RANGE: SECTION ALONG A LINE S.W. FROM STATION XXIX. Hoback Basin Moback dratnage Gros Vertre Basta Sta. XXX” Camels Back. ~~ MLILOTL . hee OM CKrOUS. BLT. E-4*Vhpss frome Gros Vertre Mts. Vere ANH, Ufa! hea Latte: Nee paae - GrosVentre Mts. Sta XM. Wind Riv. Mts. Sta.J. Hobackh-Green Riv. Divide. SCH.VE. IL. Hoback Caron Ridge. SE./mr ag.) s = — ee Hoback. Bastn, trone adtvide north of Hobacle Canow. a. Arch coast. 6. Primordtal quartile. c. @iebec limteslore. dC. CarbontthEerous. : e. Jura-Trias. Tertiary. Hasatch. g.Tertiary, red conglomerate. h.Divide.rmorainal débris trom Gros Vertre Mts. Plate XIV. sv. JOHN.|] GEOLOGY SOUTH FLANK GROS VENTRE MOUNTAINS. 211 eneissic ledges. The Quebec limestones also hereshow typical exposures, consisting of usually even, thin-bedded layers of a dark gray and dirty yellow color, weathered in rough surfaces, with brecciated and odlitic layers, the whole attaining an exposed thickness of 300 to 400 feet, more or less. . A mile or so to the southeast of the above locality, the quartzite com- poses the south-facing mountain wall. Intermingled with the débris in the talus slopes are huge blocks of quartzite, containing fucoidal mark- ings. Inthe vicinity the Quebec limestones, also, are seen folding overthe steep south face of the ridge, and in the summit they are overlaid by a heavy bed, 200 to 400 feet in thickness, of heavy-bedded light butt-gray, vesicular, rough-weathered magnesian limestone. The latter agrees well with what elsewhere has been referred to the Niagara epoch, al- though search failed to detect confirmatory paleontological evidence going to establish this identity. Indications of the above-mentioned synclinal were not again met with in the mountain flank, whose slopes are heavily loaded with the sedimentary rock débris fallen from the ledges perched along the summit of the ridge, concealing even the morai- nal deposits which are detected in many of the high benches outlying the mouths of gulehes. Thence to the debouchure of the Hoback tributary that drains a considerable area of mountain basin on the north- east of Station XII ridge, the south slope of this ridge is heavily plated with sedimentary deposits. In the angle on the west side of the debouchure of the latter stream, the mountain flank facing southward is composed of the drab or gray limestone of the Carboniferous, steeply rising into the relatively low crest in which they fold over, again descending northeast into the depression of the mountain course of this stream. The mountain in the opposite angle of the debouchure has the appearance of a huge block of Carbonifer- ous strata which has been bodily uplifted and but slightly tilted from ihe horizental. The south slope does not distinctly reveal the southerly flank of the fold, which was here eroded and concealed beneath the ba- sin Tertiary deposits. The Carboniferous deposits inthe present mount- ain reveal a thickness of several hundred feet of dark gray limestones with distinct reddish tint above—the latter color-feature being quite prevalent in these beds in this part of the range. The exit of this first considerable Hoback tributary shows a rather wide canon-debouchure, bordered on either hand by mountains sculp- tured out of the Carboniferous ledges, which appear in escarped slopes and picturesquely-weathered pinnacles. These deposits are traced well up the canon to the northeast, as far as could be seen, forming the heights along the mountainous northeast side of the valley. Below the exit, the stream, on entering the softer deposits of the basin Tertiary, presently forms a low intervale bordered by well-defined terraces. It carries a good volume of swift-flowing water, and its bed is composed of water-worn fragments of Archean, quartzite and limestone. Although it was not with absolute certainty so determined, yet, both from the relatively low elevation and nearly horizontal position of the block of Carboniferous strata composing the mountain in the east angle of the above-mentioned stream, it may be that this mass belongs to the north slope of the great south anticlinal fold. This explanation is sug- gested by the position of sedimentary occurrences in the loftier crests to the northeast, with which this mountain forms an outlying prominent spur. In the latter mountain ridge, which may be more or less parallel with that of Station XII, the strata are bent up ina great flexure, of which the southeast face is that seen from this point of view. This is 212 REPORT UNITED STATES GEOLOGICAL SURVEY. doubtless identical with the north fold into which the strata over the area of this mountain range were uplifted. Along the broken crest of this ridge, the reddish drab-gray Carboniferous and light buff-gray Ni- agara (?) limestones hold a prominent place in the rugged mountain masses and isolated peaks. But in the southeasterly continuation of the ridge the sedimentaries are, in places, removed, revealing a narrow belt of the Archeean nucleal rocks, so indicated by the peculiar mode of weathering exhibited by the rocks in the south face of the ridge and the presence of quantities of gneissic débris in the outlying slopes and stream-beds that emerge opposite this spot. This supposed Archean ridge, in places bears along the crest dirty yellowish deposits, recalling the lithologic appearance of exposures of the Primordial horizon to the west. But the outlying flanks on the south are plated by Carboniferous and Silurian strata, which rise up steeply on the lower half or more of the height of the mountain ridge. The above mentioned ridge terminates in a prominent mountain be- tween the forks of the stream whose eastern and lesser branch drains a part of the northeast flank of the north fold, and which lies to the west- northwest of Gros Ventre Peak between 8 and 9 miles distant. On the south the slope falls in an even and slightly bulging curve, correspond- ing to the planes of the flexed strata into the border of the basin, while on the west, north, and east the mountain breaks down in precipices, showing hundreds of feet thickness of the component strata. The ex- posures are mainly, if not entirely, of Carboniferous rocks, the upper part showing characteristic outcrops of harder and softer limestone beds alternating in mural exposures and steep, bare slopes that reach up to the summit. The basis rocks may belong to Silurian horizons.’ The denuded Archean ridge lies less than a mile to the north, and although considerably lower than the summit of the terminal mountain, its crest rises above the actual altitude of the lowermost sedimentary exposures in the precipitous north wall of the mountain. The presence of this mountain mass of sedimentary rocks brings out in the most vivid man- ner all these relationships and the enormous extent of erosive action ~ necessary to uncover the metamorphic core of the north fold. The ver- tical displacement in the fold at this point is probably not less than 3,000 feet. Its abrupt southern flank may be traced nearly its whole extent from the heights in the western part of the range, sometimes ex- hibiting the flexed strata, in situ, on the steep mountain sides, and then, again, eroded so as to appear in monoclinal ridges capped here and there by red beds possibly of Triassic age, whose gentle northerly declination forms the broad plateau reaching over to the culminating mountain crest overlooking the Gros Ventre Basin. This part of the range is deeply eroded by a considerable Gros Ventre tributary, in whose bed the Archzean may be revealed similar to the occurrence in the mount- ain basin of the sources of the cascade tributary flowing into the Hoback. A couple of miles southeast of the last-mentioned caton the sources of a small, independent Hoback tributary have excavated a deep amphi- theater extending back into the mountains % or 3 miles from the south border. Where it emerges, its course is interrupted by a beautiful cas- cade, the stream tumbling or sliding many feet down the steep incline over Carboniferous ledges, which throw a heavy belt across the mouth of the recess and rise high up in the mountain elevations on either side. On the east of this amphitheater the Archean is denuded, forming another spur which bears atop the whole of the Primordial quartzite capped by remnants of Quebec limestone, which latter appears in undu- lating low mural masses, weathered dark brown'sh gray. The south | Cunels I Wind Riv: Mts. Hoback- Green Drv: | | | Sout, . Ventre Peak (Sta. XML) ~ Trias. e. Laraimite. con glolerate. : y t Nal Rare a ha ‘ a LN ain oH Ai 5 OUT Pas eohiy i x men iN Rie CEN Gyncs Back. Catior of Hoback tributiery. Sta XM, Wind Fiv: Mts. Hobach- Green Dir. We BE fmag.) South lront of the Gros Ventre Range, between Camels Back and Cros Ventre Peak (Sta.XHl/. a. Archoan b. Stlirtarm. c. Carbontlerots. A Sura-Trias. e. Laramie. CLVertiary of Hobacks River g. lertiary-red conglomerate. Plate XV. eat Primes yah: ae aes weenie 7 RG i ung pS img ee o Tien 2 B?. JOHN.] MESOZOIC DEPOSITS—GROS VENTRE RANGE. 213 side of the easterly continuation of this ridge fronting the basin is also plated by the uplifted sedimentaries, while looking up the cation, the Archean is conspicuously displayed, making up the greater height of the mountain walls in the sides of the amphitheater. The latter mount- ain ridge sweeps round to the north where it merges into the main north ridge of the range 8 miles to the northwest of Gros Ventre Peak. The former described axial ridge that forms the west wall of the amphi- theater has a much more involved relationship in consequence of its median position between the two principal topographical ridges of the range in the region of the sources of Gros Ventre and Hoback tributa- ries “and forming what may be termed a third mountain ridge with spurs connecting both with the south and north ridges, with the ‘former in the vicinity of Station XII, northeast, and with the latter at a point about 11 miles northwest of Gr os Ventre Peak. These connecting spurs are but remnants left by erosion of the broad summit of the principal north fold, which indeed still retains much of its distinctive features in the elevated mountain plateau into which the central topographic ridge expands a few miles to the northwest in the direction of Station XLVI (1877) with which it forms a circuitous but almost uninterrupted chain of mountain tables from the point northeast | of Station XII, where this ridge veers round from the axial line of the fold easterly and then northwesterly, finally forming the northern bar- rier towards the northwest extremity of the range In the outlying slopes in the vicinity of the cascade nmmigtakable and most interesting exhibitions of Mesozoic strata are encountered, the first of these rocks observed on this side of the range east of Hoback Caiion ridge. Drab and bluish indurated arenaceous clays, associated with buff sandstone, containing obscure vegetable remains, outcrop in the divide west of the cascade, dipping northeastward toward the mountain at an angle of 20° to 45°. There are indications of a fold in these depos- its with more gentle inclination on the southerly flank. These deposits . bear a strong resemblance to Laramie horizons occurring in the Wyo- ming Mountains. Their exposure is also here accompanied by the brown- drab soil and numerous spring sources that are the concomitants of the outcrop of certain Laramie deposits in the latter region; and further, the presence of ferruginous-stained impressions of plants in some of the sandstone layers furnish additional evidence of their probable strati- graphical identity with those deposits. On the stream below the de- bouchure limited exposures of dark colored limestone were seen which recall similar layers that were found in lower member of the Laramie west of the Hoback Canon ridge. Next the mountain occurs a set of beds resembling the Jura-Trias conformably superimposed on the south- erly dipping Carboniferous. At the base of the Jura occurs a heavy bed of buff Magnesian limestone abounding with calcite. The‘red beds,” however, seem to be attenuated as compared with their thickness in the Wyoming Mountains. These deposits at this locality reach well up on the foot of the mountain, where they are much obscured by accumu- lations of rock débris. Outlying the Jura-Trias belt, in the extremely broken slopes rising into the high bench on the southeast side of the stream, perhaps a couple of miles below the cascade, an interesting oyster-bed exposure occurs within the limits of the previously mentioned outlying fold. The bed shows a thickness of about 2 feet, closely packed with fossil Ostrea, included in a thin-bedded grayish buff sandstone which inclines northward at an an gle of 50°, more or less, at the point examined. The exact stratigr aphical relations of this bed to the before-mentioned Lara- J14 REPORT UNITED STATES GEOLOGICAL SURVEY. Inie deposits of similar lithological appearance is not clearly discernible at this locality. Dr. White refers the most prevalent Ostrea to O. sole- miscus Meek, of the Upper Cretaceous sandstones near Coalville, Utah. As- sociated with the above form there were also recognized Barbatia coal- villensis White, and a small Ostrea which resembles O. insecura White, of the Bitter Creek Laramie series, although it may be the young of the first-named species. The strata are so generally concealed by loose ma- terials in the surface as not to afford the means for determining either their vertical thickness nor the extent of their outcrops. ‘The occur- rences are confined to the high benches well beyond the foot of the Pa- leozoic-plated mountain, in the upheavalof which they evidently par- took, although at no point do they probably remain on the high ridges of the range. The above stratigraphical occurrences probably occupy the synclinal trough intervening between the north and south folds of the range, the latter exposures pertaining to the remnant of the north flank of the south fold which here exhibits extraordinary abruptness of declivity. Two or three miles below the cascade the brook enters a pretty inter- vale and terrace bordered valley eroded out of the soft basin deposits. The hill-sides are covered with large tracts of vigorous young pines from a foot and upwards in height, amidst which rise the stark trunks of their burned predecessors. Not unfrequently the same phenomenon was ob- served at other places in this region, which seems to prove that the conditions for forest growth are as favorable to-day ag at any time in the past. Af, a locality north of Hoback Caion, a tract of burned spruce forests occupying a northwesterly slope was renewed by adense growth of young pines. Just below the valley expansion, well defined lateral moraines are de- veloped, rising 75 feet, more or less, above the stream, and clinging to the steep slopes. There are two or three of these ridges one above the other. Lower down the moraines decline and spread laterally over the more gentle declivities, in the hollows of which wet meadows fre- quently occur. The lowermost one finally converges, throwing a low embankment in the shape of a terminal moraine clear across the valley, through which the stream has eroded a narrow channel to the depth of 25 feet. How far below this the moraines extend was not ascertained. The one described was the most perfect example of terminal moraine ob- served during the visit to these mountains, although it probably does not mark the ultimate distance the ancient glacier traveled beyonds its mountain limits. The position of these morainal deposits conclusively shows that the glacier which transported their materials flowed downa pre-existing valley of nearly the same spaciousness as the present trough, and which possibly had almost equal preglacial extent within the mount- ain area as that which it there presents to-day. There was noted no unmistakable glaciation on the sedimentary mountain flanks in the de- bouchure, although the limestone-incline over which the cascade glides was bared and smoothed by the effects of the ice-fall. But within the caiion, doubtless, all the concomitant phenomena of glacial action would reward a more careful exploration than it was possible to undertake during the present visit. To the east the mountain wall curves round into a shallow recess, which is drained by another tributary of the Hoback. Occasional expos- ures of gray Laramie (?) sandstone were met with in the high sloping _ basin benches that here reach close up to the foot of the abrupt mountain declivity. The east side of the recess is defined by the ridge reaching north from the angle of Gros Ventre Peak, which here, as in the south wan Aa i “ ¥ i ala eal ad rat ia i Hi Seaver eth 4 . * , . Plate XVI. Gros Ventre Mountains. Mt. Leidy. Sta. XXX. Buffalo Fork Peak. Washakee Needles. Wind River Mountains. Gros Ventre Peak. Glaciated limestone surfaces. ‘Togwotee Pass. Sta, XXVIII. Union Peak. Sta. XV. Sta. XXIX, Green River Cafion. Frémont's Peak. Looking North from Gros Ventre Peak Ridge. a Archan. b Silurian. e Carboniferous. d Jura-Trias, e Cretaceous. /f Tertiary, including upper lignite formation. g Volcanic conglomerate, Sierra Shoshone. h Gros Ventre River. i Green River. k Wind River. 1 a i ar a yh, ie mK A Lf Harvey ee ii t Sta. XXX. e Cretaceous. By st. JOHN.] GROS VENTRE PEAK—CARBONIFEROUS SANDSTONE. 215 face of the east arm of this mountain ridge, forms long, steep talus slopes of loose débris, terminated above in a grand line of escarped ledges that rise up into the crest. Gros Ventre Peak i iS a conspicuous object. viewed from the south, having the appearance of a bulky quadrangular mass of sedimentary rocks lifted bodily to the height of nearly 11, 500 feet above _ sea-level. A low wedge of compressed pyramidal shape near the south- west angle of the mountain was selected for Station XIII, and which also served the purposes of a primary station for Mr. Wilson the previous seasane The west and south fronts break down abruptly from eleva- tions 2,000 to 3,000 feet above the basin benches at their foot. Near the angle, the heavy bedded light buff magnesian limestone, elsewhere pro- visionally identified with the Niagara, rises up steeply in the mountain foot, forming a sharp flexure with southwesterly inclination at a high. angle. These beds are succeeded by the thinner-bedded gray and red- dish-stained limestones of the Carboniferous, which curve over and at a higher elevation from the escarped monoclinal heights of the ridge. The crest of this mountain was found to consist of a narrow ridge; that to the east wrought out of sandstones into a jagged, almost ‘impassable, comb. On the north the descent is precipitous, broken by vast piles of angular débris, in 300 to 500 feet, reaching the limestone floor of an ex- tensive, glaciated mountain basin. On this side the Carboniferous strata everywhere slope off to the northeastward, at a comparatively moderate angle of inclination. In theupper portion of the basin the limestone plane is burdened with low piles and ridges of débris, probably of mo- rainal origin, and dotted with lakelets. The drainage flows east into the Green, and at the western end of the depression a south affluent of the Gros Ventre rises, flowing out to the northward across a wide belt of Jura: Trias. A section of nearly 1,000 feet vertical thickness of Carboniferous strata is exposed in the east arm of Gros Ventre Peak. The upper 500 feet consists of a heavy deposit of buff-gray and reddish tinted, lami- nated sandstone, with obliquely laminated and quartzitic lay ers, and thin bands of deeper red color. The inferior half of the exposure is made up of numerous ledges of drab and gray limestones, the upper part containing layers stained chocolate-red, and containing characteristic Carboniferous fossils—Zaphrentis, crinoidal remains, Hemipronites cre- nistria, &c. The beds incline northward, at an angle not exceeding 10°, and generally not more than 5° to the horizon. As before stated, the sandstone forms a mere wall along the crest, which gradually declines to the east, where its appearance will be again referred to further on. To the north, in low southerly-facing declivities, defining that side of the mountain basin, the sandstone horizon reappears, where it is over- laid by several hundred feet thickness of drab limestones, sandstones, and shales, alternating. Beyond the latter, in similar abrupt terminat- ing benches, typical exposures of the Triassic ‘red beds” occur, occu- pying a wide belt sloping off the gently inclined north flank of the range into the basin area, drained by Gros Ventre River. The occurrences above noted bear a strong likeness to the stratigraphical sequence of the Carboniferous observed the previous season in the Téton Range and in the Snake River Mountains, to the west. Indeed, the resemblance is so marked that it may be regarded as conclusive evidence of the iden- tity of the strata of these horizons in the regions mentioned. This middle Carboniferous sandstone, however, in the present mountain range, perhaps attains a somewhat greater development and differs lithologi- cally in its generally paler tints from the equivalent horizon in the Téton Mountains. 216 REPORT UNITED STATES GEOLOGICAL SURVEY, East of Station XIII the southern flank of the north flexure has been almost entirely removed by erosion, only limited exposures in the foot of the mountain preserving part of the curved strata. Along this part of the mountain the high outlying slopes show here and there limited exposures of the arenaceous ‘red beds” that form a belt continuous with the Triassic deposits occurring a few miles to the westward of Gros Ventre Peak, of which mention has already been made. At the present locality these deposits appear to be little disturbed ; their inclination, al- though varying from northerly to southerly, perhaps does not exceed an angie of 10°, Their position at the foot of the mountain is not favor- able to the determination of their relations to the Carboniferous deposits occurring in the latter, while on the south they are soon concealed beneath the Tertiary deposits that here gently rise up in the northern terminus of the Green and Hoback water-divide. It is possible that the uplift at this point was accompanied by a fault, with downthrow on the south, amounting in vertical extent to about the thickness of the carboniferous formations. Soon after crossing the Hoback-Green divide, in the vicinity of the lake source of a stream flowing south into Green River, the Carbonif- erous limestone, here highly siliceous, forms a low, broad areh, with gentle inclination both north and southwards. The limestone appears over a considerable area in the low, hilly and undulating wooded coun- try immediately south of the sandstone-capped eastern prolongation of Gros Ventre Peak ridge, at the foot of which lies the above-mentioned little lake-basin, partially environed by the sandstone and limestone cliffs. Thence eastward, this ridge steadily declines, flattening out into one of the low divides terminating on the west side of Green River Val- ley, about 8 miles distant. ‘The Station XIII, or north fold of the range, is not traced with certainty but a short distance east of the lake, and it seems probable that it also dies out in that direction. The west side of the stream flowing south into Green River is bor- dered above by bluffs composed of the “ red beds,” and lower down by the rather abrupt east face of the main divide separating the drainage of the Green from that tributary to the Hoback, and which is here made up of Tertiary deposits. Perhaps 3 miles south of the lake limited ex- posures of Jurassic sandstone and calcareous deposits appear in the gentle slopes on the east side of the valley, dipping about 25° south, and containing Pentacrinus, Ostrea, and Belemnites. The way thence leads southeasterly over low, undulating divides in the country interven- ing between this stream and the Green. The only rock exposures met with in this section consisted of occasional outcrops of drab clays and reddish-buff, thin-bedded, rather hard sandstone. These rusty-weath- ered sandstones continued nearly to the Green, forming low ledges here and there in the grassy slopes, and uniformly ‘inclined about south, at angles of 20° to 35°. “Lithologically they bear intimate resemblance’ to, and are probably identical with, horizons elsewhere referred to the Laramie. They are apparently in conformable superposition to the Ju- rassic deposits occurring to the north, which further suggests the above- inferred identity, unless they prove to belong to an intermediate Creta- ceous formation. But the latter formation was not recognized here, and in the absence of fossils our acquaintance with its stratigraphical com- position is too imperfect to warrant its recognition in obscure outcrops. The most southerly observed exposures of the above-mentioned Lara- mie(?) sandstones occur in the uplands on the west of Green River, about 3 miles northwest of an isolated Tertiary butte that rises from the plain on the opposite side of the river, or about 11 miles above the st. joux.|}) | GREEN RIVER VALLEY—GROS VENTRE RANGE alee mouth of Lead Creek. Ascending the valley of Green River from this point the east side of the stream is closely bordered for several miles by a low, outlying ridge at the western base of the Wind River Mount- ains, which is composed of gently-inclined Jura-Trias deposits. About 11 miles north of the butte a low arch of Carboniferous limestone rises a few feet above the river-level, the strata gently inclining north and south at an angle not to exceed 10°, with which the superimposed Meso- zoic formations conform, as displayed in the exposures on both sides of the valley. The axis of this arch lies a little north of east of Gros Ventre Peak ridge, and in its physical character it offers little by which it may be distinguished from the low arch immediately south of the eastern ter- minus of the above-named ridge, as mentioned above. In case of their identity the trend of the Gros Ventre Peak, or north fold of the range, curves round from a southeasterly course, which it has hitherto held, to an easterly direction on approaching the Wind River uplift. The before- mentioned outlying ridge on the western foot of the latter range bears the record of dynamical disturbances that transpired in both zones of mountain elevation. The north flank of the Gros Ventre Range was not approached nearer than the outlying and probably geologically parallel low ridges that lie within the Gros Ventre Basin. But from the latter and more distant mountain peaks situated in the northern part of the Wind River Range and in the Mount Leidy highlands, to the northeast and north, respect- ively, a general knowledge of its geological structure was acquired. From the points of view above designated the great north fold of the range more or less closely corresponds to the prominent mountain crest that constitutes the eastern half of the northern barrier. ‘To the west the tributary drainage of the Gros Ventre River has eroded the north flank of the fold forming the culminating mountain ridge that makes a slight north deflection from the eastern portion of the ridge with which its topographical relations are most intimate. This ridge throughout ranges in actual elevation between 10,000 and 12,000 feet, bearing a grand chain of architectural peaks sculptured out of the uplifted sedimentaries. As has been already stated, the north flank of the range presents a comparatively gradual and remarkably uniform declivity descending into the basin area of the Gros Ventre. Its component geological for- mations embrace the entire sedimentary series of the region, from the Silurian to the Jura-Trias, inclusive. In the eastern half only the Pale- ozoic formations, chiefly the Carboniferous, remain along the main mount- ain crest, while to the west, in the before-mentioned north deflection of this topographic crest, the Triassic “red beds” hold a prominent place on the flank of the monoclinal ridge. But what is regarded as the west- erly continuation of the geological ridge or north fold, which was exces- sively eroded by the sources of the previously-mentioned south affluent of the Gros Ventre, which rises 5 or 6 miles to the northeast of Station XII, exists as a mere remnant, on the southwest flank of which low out- liers of nearly vertical strata were seen from Station XLIV at the west end of the range the previous season. The erosion of the Little Gros Ventre, which heads in this quarter, has stripped the sedimentaries from the axis of the fold, revealing the quartzite and possibly also a belt of the metamorphic nucleus of undetermined extent along the course of its caiion. The mountain ridge lying between Gros Ventre River and Little Gros Ventre Creek, and which constitutes the extreme northwest extrem- ity of the range, exhibits the lower limestone and middle reddish-tinted sandstone members of the Carboniferous in long lines of monoclinal 218 REPORT UNITED STATES GEOLOGICAL SURVEY. exposures lying a little to the north of the axis of the north fold and ' sloping off to the northeastward at a moderate angle of inclination. The middle sandstone member of the Carboniferous, which is well- developed in the latter quarter, is conspicuous on account of its red color. In this respect it presents a marked contrast to the lithologie appearance of the same horizon noted towards the opposite extremity of the range, in the vicinity of Gros Ventre Peak, and which might lead to its being mistaken for the Triassic “red beds,” were its stratigraphical associations locally masked or not recognizable in distant views, such with which the geologist too often has to be content. The Jura-Trias occupies a relatively wide belt on the north flank of the range, even rising into quite prominent tables and foreland benches, descending in long inclines, and merging into the area of the basin proper. The Jura was hardly touched at a single locality in this quar- ter, its presence being determined chiefly from the lithological appear- ance and sequence of its exposures. It seems to be in part made up of deep drab and chocolate-red variegated clays, sandstones, marly indu- rated layers, and drab limestone. Owing to the prevalence of clayey constituents the exposures are seldom satisfactory. On the contrary, the deep-red arenaceous shales and sandstones of the Trias are exposed in numerous and extensive escarpments, and wherever in the region of its occurrence the soil from one cause or other has been disturbed, a gleaming spot of red color, may be contrasted with the deep-green of herbage-clothed slopes, discloses its presence. Sta.XLVI[(187Z) Tétgn Mts. —— = = = = == Cr — ae genes Tt, — 2 : Vi = le, Tg Gut ee Geoe Tae re Fe Cy WMEAPELLER Ue SU a eae ag nate ay i 1 Rea H i an oy Ma Ts hii vii ery i" ) Bah Rae casi ri ce MORE) RG aeek wt At caine ut Pays Ste, XUL {18 76.) ere Sta.XIVI(1877) Téten Mets. = 2 z i= ee =S Zs Meese PERT ee North Flarh: of the Gros Vertre Range , frome Stattore XXIX. a. Archeaz. b. Patleeoxote. ce. Jura-Trtias. d. Cretaceous. e. Tertiary. Plate XVII. Oelecle Wada Wee GROS VENTRE BASIN. Gros Ventre River drains a large basin tract lying to the north of the mountain range bearing the same name, and which is about twice the superficial extent of the upper basin of the Hoback on the south of that range. ‘To the southeast it is defined by the low, inconspicuous divide stretching over from the north slope of the Gros Ventre Range, east, to the great foreland bench on the west flank of the Wind River Range ‘south of Union Peak; the elevated water-shed that spans the gap be- tween Union Peak at the northern terminus of the latter range and the great sedimented volcanic mountains in the vicinity of Towotee Pass, a distance of 24 miles, constitutes the barrier on the east between this drainage and the upper course of Wind River; while it is separated from the valley of Buffalo Fork by the low mountainous highlands dominated by Mount Leidy, which form the northern boundary of this special drain- age basin. Thus defined, the Gros Ventre Basin has an area of 500 square miles, approximately. The main stream rises in a glaciated defile a few miles south of Union Peak, and once it emerges upon the elevated park-like slopes at the foot of the latter mountain, it pursues a general course a little north of west for the distance of about 42 miles to the point where it gains the plain of Jackson’s Basin. It receives several good-sized tributaries from the surrounding highlands, and is of additional importance from the fact that it affords easy communication with the Wind River Valley Via Union Pass at the north end of the Wind River Range. Chiefly occu- pied by easily eroded tertiary deposits, the general superficial contour, of the basin is exceedingly broken, especially in the central and north- ern portion. The streams generally flow in narrow valleys, often deserv- ing the name “cations”; lower down the main valley expands, affording small tracts of intervale and terrace land. The uplands present pleasing variety of forest and herbaceous openings in the undulating southeast- © ern quarter, where the woods and meadows were found stocked with numerous bands of elk and deer. Butin economic importance it scarcely equals the beautiful basin of the Hoback (its general elevation being in the neighborhood of a thousand feet higher), save in one particular, its extensive deposits of coal. Geologically, the area above alluded to constitutes but a part of the great Cenozoic basin that stretches north until it is lost beneath the lava flows and volcanic ejectamenta that mask the whole country around Yellowstone Lake. Its present orographic boundaries are, on the west, the Téton Range; south, the Gros Ventre Mountains and the northern end of the Wind River Range; to the north and east, except for the presence of the probably isolated uplift on Buffalo Fork, described in the report on the Téton district the previous season, it has an extent reach- ing far beyond the limits of the present district. It is not the province of this special report to attempt the detinition 219 220 REPORT UNITED STATES GEOLOGICAL SURVEY. of the original boundaries of this great Tertiary basin. Within the area of this particular district observation seems almost to warrant the con- clusion, if it fails to establish the fact, that the waters of that time com- municated with the basin area of Green River, although denudation has © interrupted the continuity of the sediments then accumulated in the in- tervening straits between the Wind River and Gros Ventre Ranges. But in the latter quarter the vertical displacement or upheaval, in the region of the eastern extremity of the latter range, was not sufficient to erect an insurmountable barrier to the encroachments of the waters on either hand and the eventual union of the north and south expansions of the Cenozoic sea. From a geological point of view the evidence is somewhat conflicting, inasmuch as it is not yet known with that cer- tainty necessary to well-founded generalization to what extent the Cenozoic deposits themselves have been disturbed by forces acting within the present orographical boundaries, and, until the latter problem shall have reached solution, the original extent of surface occupied by these sediments must remain more or less a matter of conjecture. In the Wyoming Mountains they are known to reach high up on the summit in places, where they rest unconformably upon older geological formations ; at the same time their inclination, although moderate, shows that dis- turbing influences had not ceased subsequent to their deposition. Al- though in the Gros Ventre and Buffalo Fork uplifts these deposits at no point were observed in the more elevated portions of the mountains, yet they are more or less disturbed wherever they appear on the mountain flank. Whether their disturbed condition is due to elevatory move- ments within the mountain zones or to subsidence in the outlying basin areas is not so evident, although within the present topographically-de- fined basin area these beds exhibit marked evidence of disturbance, which resulted in their being uplifted into more or less well marked folds, whose parallelism with one or other of the bordering mountain up- lifts may be readily recognized. The northerly or northeast inclination of the Paleozoic and Mesozoic formations off the north flank of the Gros Ventre Mountains, as has been indicated in the preceding chapter, extends along the entire south border of the Gros Ventre Basin, so that it is difficult to draw the exact line - defining on the one side the basin limits from the mountain foot on the _ other. Of the above formations only the Mesozoics enter the basin area proper, where they occupy a rather wide belt in the southeastern border portion. In the westerly-rising declivity of the Gros-Ventre-Green di- vide, at a point perhaps 8 miles about north-northeast of Gros Ventre Peak, the Triassic “red beds” arch partially over a low fold, the eastern flank of which has been eroded and is at present covered with dense forests. East of the latter fold the channels of streams flowing down either side of the divide reveal the presence of the soft yellowish sandstones and light-drab clays of the Tertiary(?); but on the declivity rising up on the Wind River Mountains to the east, the surface is composed of drift ma- terials evidently derived from that range. West of the Triassic fold, in the gentle slopes descending the north flank of the Gros Ventre Range into the shallow intervening depression, the same deposits outcrop in low bluffs, the northerly inclination of the surface conforming to the dip of the strata. This low arch was not again recognized to the northwest, and it may be of merely local extent. In the southwestern half of the basin the strata are complicated by a series of flexures lying quite within the basin limits, although, of course, intimately related to the mountain upheaval culminating in the north fold of the Gros Ventre Range. This belt of flexed basin deposits extends Plate XVIII. Wind River Mts. S.S.E. S. mag.) Gros Ventre Mts. Sta. XIII. nT AT EATEN To er Oe — Gap between Wind River and Gros Ventre Ranges. a Drift-covered wooded and open slopes. } Archean, south of Green Iiver Canon. c Paleozoic. qd Trias. e Tertiary. (From Station XX VIIUT.) s BT. JOHN.] GROS VENTRE BASIN—CRETACEOUS. 22K a distance of 5 miles or more along the Gros Ventre, or from the upper main forks to the valley of a considerable south tributary that skirts the foot of the Carboniferous plated mountain ridge which here forms the northernmost culminating crest of the range. The exposures are well displayed but for occasional interruptions in the continuity of their visible outcrops in the terrace bluff along the southeast side of the stream. The rocks involved in the flexures are of Cretaceous age, according to the specific identity of the few fossils here obtained, as kindly determined by Dr. White. The northeast-facing mountain slope to the west of the before-mentioned Gros Ventre south tributary is heavily plated by the Jura-Trias, the outlying lower slopes in places showing low ridges of light-buff deposits, which are presumably referable to the Cretaceous. The strata are again exposed in the east side of the valley, and thence to the main forks of the Gros Ventre they are exhibited in a well-defined - synclinal and anticlinal fold, the axial trend of which is in a direction a few degrees east of south and west of north, changing farther east to about southeast-northwest. A diagram of the geological section here alluded to is given in an accompanying plate, the horizontal distances being rough approximations, in explanation of which is appended the following description: Section along Gros Ventre River. No. 1-4. The formations, Carboniferous to Cretaceous, inclusive, that rise up on the northeast flank of the Gros Ventre Range have been al- ready mentioned. The outer border of the Cretaceous, No. 4, at the mountain foot is concealed by morainal deposits, No. 5, and alluvial ma- terials in the valley. It may be that in this space the Cretaceous strata have been eroded over the site of a low fold corresponding to a previously mentioned broad low arch in the “red beds” immediately outlying the foot of the range to the northeast of Gros Ventre Peak. No. 6. Gray, indurated argillaceous beds and drab clays, and soft gray sandstone, with thin seams of cannel-like coal. Dip northeastward. No. 7. Gray, argillo-calcareous, indurated beds, gray sandstones and drab clays, with obscure plant-remains, and thin layers of lignite. Dip 20°, about HE. 30° N. No. 8. Space, showing only obscure rock exposures of similar charac- ter to above and following. . No. 9. Indurated drab shales and drab and brown clays, and gray sandstone, underlaid by a thick deposit of heavy-bedded, gray, buff: weathered, soft sandstone. In the overlying drab shales, which also form a heavy deposit, at one place a thirty-inch bed of coal was observed, below which other thinner seams were seen, the outerop crumbling on exposure to the weather; dip 55°, about W. 10° 8. Overlying the coal, a small ovate leaf with crenate margins occurs in a drab indurated ar- gillaceous bed, together with comminuted vegetable remains, the sand- stone also affording what appear to have been large stems of trees, but very imperfectly preserved. No. 10. Gray sandstone, dip little south of west at an angle of about 60°. This is probably identical with the sandstone next mentioned below, having arched over a sharp anticlinal fold, the axis of which has been eroded or otherwise concealed at this point. No. 11. Half a mile or thereabout below the main forks of the Gros Ventre, a heavy deposit of gray and bufi-gray, coarse-grained, heavy and thin-bedded sandstone appears in the bluffs along the left side of the stream, and lower down underlaid by dark or brown drab clays showing 222 REPORT UNITED STATES GEOLOGICAL SURVEY. only obscure exposure; dip H. 8° N., at an angle of 50°. At one point the sandstones, which are in places calcareous, afforded a few imperfectly- preserved fossils, amongst which Dr. White has determined the follow- ing Cretaceous forms: Mactra arenaria Meek?, Ostrea sp.?, Inoceramus erectus Meek?, and other undetermined conchifers. The I nocerami have a considerable vertical range in the heavy sandstone deposit, although its presence is chiefly determined from mere fragments showing the pecu- liar shell structure. No. 12. The steep hills in the immediate vicinity of the main forks of the stream are made tp cf gray, buff-weathered sandstones and drab clays, inclined at an angle of 55° H. 33° N. No fossils were observ ed in the latter beds of the above section, but there is no doubt of their conformable superposition to the strata de- scribed under No. 11, and which, together with No. 4-11, inclusive, constitute a heavy series of light gray and yellowish- weathered sand. stones and drab clays occurring “within the basin area proper, and whose disturbed condition is apparently attributable to, and synchronous with, the disturbances that folded the strata over the region of what is now the Gros Ventre Range. Station X XIX was located on a commanding crest of the ridge just west of the main branch of the Gros Ventre, about 6 miles southeast of the forks. The view from this point commanded nearly the whole northeastern front of the Gros Ventre Range, besides nearly the entire extent of the basin from a nearly central position. The nature of the strata composing the ridge itself, in the main soft sandstones and clays, dipping northeastward, affords few rock exposures of any considerable vertical extent. But the surface of the whole region, reaching up to and crowning the sharp ridge on which the topographical station was made, is strewn with the remnants of a remarkable conglomeritic deposit, whose origin might at first be mistaken for Quaternary, as indeed the degradation and dispersion of its component materials was affected during that period. Approaching the valley of the Gros Ventre, the Cretaceous deposits have been extensively eroded, but to the southeast they rise up into higher ridges, which still farther in that direction have been denuded, bringing to view the Triassic ‘‘red beds” and drab vari- egated deposits of the Jura in the before-mentioned low arch to the northeast of Gros Ventre Peak. This arch is about southeast of Station XXIX, to the east of which the Cretaceous deposits, if they still exist in that quarter, merge into the undulating drainage divide defining the southern limits of the basin. In this connection may be mentioned limited occurrences, in the direct line of the south-southeasterly strike of the deposits above noticed, that were examined along Green River just above the great bend. There here occurs an exposure of gray and bluish clays with bluish indurated fine arenaceous layers, which break into narrow slabs or post-like masses, the dip of the beds being about N. 40° E., at an angle of 30°. The isolation of the exposures and the absence of fossils renders the deter- mination of their stratigraphical position a difficult question. But there is certainly a somewhat striking coincidence in the direction of their strike, which, at least, suggests a possible identity with the above-men- tioned deposits in Station X XIX ridge. The general northwesterly strike of the Cretaceous deposits, in the Gros Ventre section above described, apparently veers round more to the west on passing into the region nor th of this stream. This is indi- cated by the occurrence of very similar lithelegical manifestations iz the umole slopes inidway between Mount Leidy and the Gros Ventre, Plate XIX. Gros Ventre River: Cafion in conglomerate. a Conglomerate. (Looking N. W.) b Upper lignite. st. JOHN.| GROS VENTRE BASIN—-CONGLOMERATE AND COAL. 223 and in the regular order of stratigraphical superposition to the varie- gated Jura and unmistakable “red beds” of the Trias, all of which, so far as can be made out at a distance, belong to the northerly-inclined flank of the northwestern extremity of the Gros Ventre Range. But these deposits appear over a comparatively narrow belt in this northern slope of the basin, at least not of greater width than along the Gros Ventre, while in the crest of the Mount Leidy highlands they are super- seded by later deposits, presently to be mentioned. The main branch of the Gros Ventre, after leaving the elevated mountain flats, flows in a gradually deepening narrow valley, in whose sides fine exhibitions of the Tertiary are met with, extending as far down as a point about 4 miles above the two principal forks, where the stream enters the above-mentioned Upper Cretaceous horizons. The Tertiary deposits are based upon a heavy accumulation of brownish-drab con- elomerate, several hundred feet in thickness, and which is composed of thoroughly water-worn and rounded pebbles and small bowlders consist. ing almost exclusively of variously-colored quartz and quartzitic frag- ments, rarely a metamorphic pebble being seen. The conglomeritic char- acter predominates through a great vertical extent of the horizon, with, however, intercalations of soft yellowish sandstone of’a more or less local extent, and which is essentially of the same character as the fine brownish drab or gray and slightly calcareous matrix of the conglomerate. Above, — the sandstone layers increase in thickness and frequency of occurrence, alternating with thinner layers of conglomerate and green and drab clays. The main mass of the conglomerate in the wierdly-eroded exposures along the canoned portion of the stream was found to contain fragments of tree- trunks, but which are so changed by ferruginous infiltrations and decayed. as probably to be indeterminable. In the section (a diagram of which is associated on the plate illustra- _ ting the last preceding section with which this is in direct continuation to the northeastward) exposed along the northeast fork of the Gros Ventre, the conglomerate reappears in the hills at a place about a mile above the forks, where it is seen to rest with apparent non-conformity upon the sandstone No. 12 of the section last described. The dip is to the northeastward at an angle of about 10°; on the main stream at the first-mentioned exposures of this horizon the inclination is about 5° in the same direction. The exposures continue about a mile before they finally pass beneath the level of the stream, the inclination gradually lessening, ascending the valley to the northeast. This horizon is repre- sented by No. 13 of section diagram referred to. The conglomerate is conformably overlaid by a still greater thickness of soft yellowish sandstones, light and drab clays, forming broken hills and slide-benches, in which the strata are usually more or less concealed by the soil derived from their degradation. The latter deposits also incline gently northeastwardly, occurring along the valley for the dis- tance of perhaps a couple of miles. This series is also finely developed on and to the east of the southeast fork, where, at a point about 8 miles above the furks, Mr. Perry secured a very interesting detail section. In a vertical thickness of about 1,000 feet, made up of generally light buff calcareous sandstones and clay shales in about the proportion 2 to 1, and including five beds of limestone aggregating 40 feet in thickness, there were found eighteen distinct lignite horizons, composed of 47 lay- ers, varying from thin seams up to beds 24 feet thick, and aggregating about 28 feet. The exposed outcrops of the coal beds usually are more or less decomposed, and while, in the main, the beds are thin seams from less than’: inch to 8 inches thick, there are at least 11 showing a thick- 224 REPORT UNITED STATES GEOLOGICAL SURVEY. ness of 10 inches and upwards each ; several of the thinner seams sepa- rated by thin partings of clay might be mined as one bed, many of them showing an aggregate thickness of 20 to 30 inches of coal. Commi- nuted vegetable remains occur throughout, and at. one carbonaceous horizon in the middle portion of the series a few imperfectly preserved fossils were found belonging to the genera Unio, Hydrobia?, Spherium, which Dr. White provisionally refers to Bear River Laramie forms. In nearly horizontal sandstones in the upper part of the ‘section examined by Mr. Perry a species of Viviparus closely allied to, if not identical with, V. paludineformis Hall, was obtained, which, according to Dr. White, indicates the Wahsatch age of the supralignitic horizons. The latter deposits, on the before-mentioned northeast fork of Gros Ventre River, continue for a distance of 1$ to 2 miles; the exact thickness attained by them is difficult to determine. The upper por- tion may be destitute of coal deposits, although presenting great uni- formity in composition and lithologic characters. Overlooking a more or less extended belt of the outcrops of this series, it presents a light buff color that readily distinguishes it from the brownish inferior con- glomerate, as also from the overlying series. But it would be prem- ature at this time to attempt to draw the line of demarkation between the lignite-bearing inferior portion with its supposed Laramie inverte- brate fauna and the apparently conformable upper portion character- ized by the Viviparus paludineformis (2), except arbitrarily; while the non-conformity between the basis conglomerate and the subjacent Cre- taceous deposits is unmistakable. The above horizon is succeeded to the east by a series of variegated pale red or pinkish clays (No. 15), in apparently conformable superposi- tion, and inclined gently northeastward. The outcrop of this member is traced as a somewhat narrower belt, distinguishable by its peculiar color at long distances. It frequently appears in bluffs and denuded slopes, in which respect, as also the banded disposition of the coloring matter, pink and light drab, forcibly recalls the peculiar deposits so prominently developed in the Wind River Valley, east of the present basin. To the south these deposits are not so distinctly traced, so that at present it would be impossible to define their areal extent in that quarter. In the opposite direction, however, they are seen to rise up in the broken slopes culminating in the Mount Leidy highlands on the north border of the basin, beyond which again they were not with cer- tainty recognized. A considetably thicker series of very light drab and buff deposits, probably arenaceous clays and soft sandstone, including pale, orange- colored horizons (No. 16), overlies the last preceding deposits, rising up into and forming the bulk of the sedimentary deposits in the crest of the watershed separating this basin from the upper valley of Wind River on the east. They are but slightly disturbed from their original horizontal position, as appears from such exposures occurring along the streams descending either slope of the watershed. About midway be- tween Union and Togwotee passes, where the watershed is most de- pressed, 9,800 feet altitude, these deposits are clearly continuous with those occurring on the headwaters of Wind River. This region is gen- erally well wooded, and but for the barred bluffs along the drainage channels intersecting the watershed, its geological structure might not be so easily made out in the course of a hasty examination. No fossils were found in these deposits by which they might be compared with elsewhere well-determined Tertiary formations. To the south they are hidden beneath Quaternary débris ov er exten- U.S.GEOLOGICAL SURVEY é E. WASHED BLUFFS ON WIND RIVER. WASATCH GROUP oP sires ly Saylicu) S st. JoHN.] CONTINENTAL WATER-SHED—MT. LEIDY HIGHLANDS. 225 sive areas in the slopes in the vicinity of Union Pass. Just north, how- ever, on the head of Warm Spring Creek and upper drainage flowing to the Gros Ventre, they appear in the blufis, showing nearly horizontal strata of yellow and brown sandy clays and soft yellow sandstones. The ridges separating the drainage are here often overspread by quan- tities of water-worn and rounded quartz pebbles, strikingly like the ma- terial derived from the degradation of the before-mentioned conglomer- ate lower down the Gros Ventre. But the surface is generally envel- oped in the morainic débris consisting chiefly of Archean bowlders. Ap- proaching Station XX VIII, alow conical eminence rising on the summit of the watershed 11 miles to the northwest of Union Peak, attaining an altitude of 10,142 feet, the drift material shows constantly-increasing accessions of volcanic fragments and chalcedony. The station eminence is composed of a brownish-green easily-weathered deposit, intermingled with which, at the surface at least, occur quantities of basalt, red to brown and dark scoriaceous lavas, drab, brown, and pink trachyte, vol- canic conglomerate and green-stained quartz conglomerate, such as oc- curs in Togwotee Pass, together with beautiful green volcanic glass and chaleedony, and fragments of fossil wood. Indeed, the hill would seem to be made up of fragmentary volcanic products of a kind identical with the great volcanic deposits in the neighborhood of Togwotee Pass. The green-stained basis deposit, also, is like that occurring beneath the great voleanic conglomerates at the latter locality, and which, the previous season, was found to extend some distance from the summit of the pass along the upper course of Wind Liver, where it in turn rested upon light buff and drab Tertiary deposits, probably identical with those no- ticed above. A few miles to the north of the latter locality the flowed lavas connected with the high volcanic plateau that culminates in a low dome (the same occupied as Station LI by the Téton division of the sur- vey the preceding season), 6 miles south-southeast of Togwotee Pass, first appear in situ (No. 17 of the section diagram), and thence round by way of that pass the watershed bears a heavy mantle of volcanic rocks. The stratigraphical appearance of these deposits in the latter quarter were noticed itn the report epon the Téton district, 1877. The range of hills separating this basin from Buffalo Fork drainage is apparently largely made up of the above-mentioned formations. This highland belt was crossed at a point about 10 miles east of Mount Leidy, in the vicinity of one of its culminating peaks, Station XXX, which has an altitude of 10,338 feet above the sea. ‘The divide is‘ here capped by the conglomerate, No. 13, composing several hundred feet thickness of the summit strata, and inclined about 8. 12° E., at an angle of 10° or less. The conglomerate is here interbedded with hardish, gray, dirty-buff weathered sandstone containing fragments of twigs and tree trunks. The rock in the high summits weathers in precipitous slopes and steep taluses, through which protrude sharp aréte-like but- tresses which give to the weather sculpture of these eminences so pecu- liar and striking an appearance seen from adistance. East of this point the conglomerate is overlaid by the same succession of formations as noticed in Gros Ventre River section, 10 miles to the south, with which, indeed, these exposures have uninterrupted continuity. At the time of our visit the present season (October 11) the country was covered with snow; but in the numerous abrupt hillsides the geological formations could be readily recognized, and especially so in the case of the great interlignitic conglomerate, which rises up into the heights that mark the irregular crest of the Mount Leidy highlands. The inferior coal-bearing series, composed of softer materials, was not 15 H 226 REPORT UNITED STATES GEOLOGICAL SURVEY. so markedly displayed in escarpment exposures, although it also doubt- less largely enters into the basis deposits of this highland region. It is not impossible that the lignite seams reported the previous season on Elkhorn Creek, at the northern foot of Mount Leidy, belong to the latter — Series, in which case they should, together with their accompanying strata, be referred to the Cretaceous instead of the Tertiary as in the re- port upon the Téton district, 1877. The strata of a widish belt upon the western and southern flank of the highlands, which quarter, for want of time, was not visited, are also probably referable to the same age. The conglomerate reappears in characteristically weathered summits north of Butialo F Fork, and it is very probable that the vast accumula- tions of drift-like débris, noticed by Professor Bradley in the high divide between the latter stream and the sources of Snake river, were derived from the breaking up of this deposit. It has contributed an immense amount of loose materials to fluviatile deposits in all the valleys of both the Buttalo Fork and the Gros Ventre basins, and most probably the water-worn and rounded quartz pebbles that enter so largely into the composition of the bars in the bed of Snake River along many miles of its course through Jackson’s Basin, and even in its lower valley below the Grand Canon, are attributable to this conglomerate formation. The streams south of the Gros Ventre Range are bedded with different and greater variety of rock materials, which may be traced to ledges in the surrounding mountains. It is said by old prospectors that this deposit affords gold, invariably in very minute particles. In the Buffalo Fork region the deposit descends to the northeastward at a gen'le rate of inclination, as shown in the fine exposures north side of Pacific Creek, a few miles above its mouth. This northerly ineli- nation was also observed within the Mount Leidy belt, where the con- glomerate seems to form a very low, broad, undulating swell. Above the mouth of Blackrock Creek, five or six miles, a limited exposure of a conglomerate ledge appears in the south bank of the river, the relations of which to the higher occurring exposures could not be ascertained. if the latter ledge is tn sitw it shows that these strata also partook in ithe disturbances of the Buffalo Fork Peak uplift, low on the flanks of ‘which Prof. Theodore Comstock found highly inclined lignite-bearing ing deposits. The latter, lam now prepared to believe, are of Cr etaceous age, aS Was originally stated by Professor Comstock in his report. to ‘Captain Jones (Yellowstone Expedition, 1873). It was the intention the present season to carefully examine the borders of Buffalo Fork Peak uplift with the view of gathering as complete data as possible regarding the coal deposits known to occur there; but the early approach of winter snows forced the party to withdraw, leaving the northern part of the «district unworked. In the right bank of Buffalo Fork, near the confluence of Blackrock Creek, exposures of bluish-drab indurated argillaceous beds and shales, with gray and buff weathered sandstones appear, inclining at an angle of about 10° to the northward. The shale here afforded abundant vege- table remains, among which a small long ovate leaf resembling the plum was most numerous. These plant remains, which were the only paleontological evidence obtained bearing on the age of these deposits have not been determined, so that we have to depend on stratagraphical ‘data to determine this question. A mile or less to the north on the Blackrock, apparently identical strata incline northeastwardly at an angle of 15 to 20°, which would appear to show a nonconformity with the conglomerate similar to that noticed on the Gros Ventre. Appar- ently the same series of deposits constitute the bulk of the hills north of Butialo Fork, and extend west to the border of Jackson’s Basin. S GEOLOGICAL SURVEY AKE. | RIVER MOUNTAINS -GLACIAI WIND SECTIONS ACROSS GROS VENTRE -BUFFALO FORK BASIN. Gros Ventre Mts. Sta XXX. Buttotlolork Peak. 72,000 fe. Gros Ventre lity. : Litkhormn Cr: Blackrock as Btttele Fork. Gi Wr chiens: b. Stlurtare. ce. Carbortrerous. a ad. Ture -Trias = e. Cretaceous, with coal 5 f. Conglomerate. Gg Volcanic. Gros Ve ntre Mts Gres Ventre ai Bast. Watershed is Sta. LI. 3 v & © $ < = Gras Ventre Mts. : Gntinental Watershed. { F EK : M Gros Ventre. Sta XIX ridge f Basar 3 Sta XXVIII. BS $ Sra Plate XX. — ENE. SEC Gros VerntreMts. 2,000 te. Stare PODS e. Cretaceous, w\-Trias “©: Gros Ventre Mts. LESSOR Re | ; ee SEER Rereorares a | ees = SSS cd }, SRR SS a a OT ASSO IS $36 > & san SEES SS Cros Ventre Mts. 72022 LE. te st. JOHN.) GROS VENTRE BASIN CONGLOMERATE. 227 The apparent local occurrence of the conglomerate, which is, so far as known, restricted to the region north of Gros Ventre Mountains, would suggest the environing mountain ranges, the Teton, Gros Ventre, and Wind River, as the sources whence its component materials were de- rived. Observation, as yet, is too limited for the purposes of tracing the physical history of the horizon and noting the changes in the component materials remote from the ancient shores of the basin in which they were deposited. The beautifully rounded condition of the hard quartz frag- ments and the thorough comminution of the softer rocks which are mingled with the deposit in the condition of fine sand and limy cement, evidently show the work of wave action. At present the deposit has not been observed in immediate contact with the rocks in the mountain bor- ders whose degradation contributed the materials, so that it is not known to what extent the trituration of these materials had progressed along the immediate shore. The peculiar conglomerate in the region of the northern end of the Hoback Canon ridge on the south slope of the Gros Ventre Range, described ona preceeding page, possesses in a marked man- ner the peculiarities of a shore deposit, from which the softer rock frag- ments have not been eliminated or so completely reduced by attrition as is the case in the Gros Ventre Basin conglomerate; but here the data in hands, so far as relates to tracing identity with the latter formation cease, although that deposit is also of Tertiary age, but presumably of later date, or Pliocene. CHA PT) By Velae WIND RIVER RANGE. The Wind River Range has a general course a little west of north and east of south of about 88 miles, and a breadth of from 12 to 32 miles. Within the present district there lies some 36 miles of the northern por- tion of the range, of which it forms by far the most prominent orographie feature. The southeast corner of the district lies in the heart of the mountains a few miles to the east of New Fork Peak; and thence the east boundary line descends north, gaining the Wind River Valley at the eastern foot at a point nearly due east of Union Peak, the most northerly eminence of the range. Circumstances beyond our control prevented the party penetrating the Alpine region, except at the northern ex- tremity of the range. But to the south, Mr. Wilson, the previous sea- son, succeeded in carrying the primary triangulation to the dominating summits at Fremont’s and, I believe, New Fork Peak, revisiting in com- pany with Dr. Hayden, at an earlier date the present season, the same region; so that the topographic features of the heart of the range, with its rock structure and interesting glacial phenomena within the district, have been subjects of investigation by several members of the survey. Our own work, however, was mainly confined to the flanks of the range, and chiefly within the belt occupied by the uplifted sedimentary forma- tions, the exhibition of which, as displayed in the gorges through which the streams descend on their way to the plains, is of extreme simplicity. Archean area.—The summit of the range within this district is com- posed of Archean rocks, forming a broad wedge-shaped area with the apex resting on Union Peak and expanding to the south-southeast, where along the forty-third parallel it may reach a maximum width of 30 miles. The watershed and main topographic crest lies to the west of the central line of this area, forming a massive ridge to the south out of which erosion has sculptured the huge mountain summits dominating the range. The whole summit is lifted above timber-line between 2,000 and 3,000 feet. To the north the summit widens into a plateau, its surface paved with weathered blocks of granite and rising here and there into broad-based domes or craggy ridges a few hundred feet in elevation. This is the character of the range from Union Peak south to near the line of 45° 15’. The eastern face of the main ridge, from a point opposite the sources of Torrey’s Creek, south at least as far as Little Wind River, breaks down precipitously, the stream sources draining this side of the range rising in elevated rugged basins and amphitheaters along the foot of the summit ridge. The united waters of these streams generally take a direct course transverse to the general direction of the range, and soon enters the broad belt of uplifted sedimentary formations reclining on the flank of the range, in crossing which they have eroded deep, picturesque cafions displaying the complete Paleozoic and the lower members of the Mesozoic series of formations. This belt of uplifted 228 Plate XXII. Gros Ventre Mountains. W. (mag.) SS ES Cation of North Fork of Green River. a Glaciated Archean ledges, b Moraines, North Fork: Caron. Green River Carton. ' Gros Ventre Feak:. B. SETmag) Sie a. Archwan. b. FPaleceoxore. West Mlanh of Wind River Ra nge, veietnity of Green FRitver Catone. co hira-Trias. d. Moratnal ridges Plate XXII. MGT Pike: e, aay ei int Hee if x Hay) t a us Bye ee = Dwg ey 7 sl i - WH 67 On RS | r Wit ii CU By) Shy ales, SNe el RN (Rae ANG a. Archean. st. JOHN.|}] WIND RIVER MOUNTAINS—-METAMORPHIC ROCKS. D4) sedimentary rocks locally forms two or more distinct subordinate paral- lel ridges whose aggregate makes up an outlying mountain ridge that may be traced nearly the entire length of the range. The latter, as seen from the valley, forms the prominent orographi¢ feature of the range, the high Archzan summit only appearing here and there up through the openings formed by the canons of the descending streams; but from the higher or inner crests of the sedimentary belt the broken Archean basin area is overlooked, terminated by the precipitous eastern wall of the culminating summit ridge only a few miles distant. The appearance of this lofty mountain barrier is indescribably varied and sublime. The stream beds are choked with confused piles of bowlders, and the rock surfaces everywhere bear unmistakable evidence of glacial action. The basins of all the streams that rise within the Archean area present more or less perfect examples of roches moutonues ; indeed the whole region s replete in these most interesting and varied phenomena. On the west, the summit ridge is flanked by an exceedingly rugged elevated Archean plateau or bench several miles in width. Thestreams that penetrate to the main crest flowin profound gorges walled by gran- ite often many miles in length, as is the case with Fremont’s Creek and Green River. The lesser drainage channels, rising in the outer edge of the outlying mountain plateau, often head in a cul de sac hemmed in between precipitous granite escarpments hundreds of feet in height, and flow out through cafions scarcely inferior in the grandeur of their scenic surroundings to those eroded by the principal water courses that drain the western flank of the range. Throughout nearly its entire extent within this district, the western edge of the Alpine plateau pre- sents the appearance of a huge terrace escarpment which abruptly breaks down to the comparatively low, narrow belt of foot hills that slope into the valley of the Green River. Ancient glacial phenomena are here met with on a scale of great magnitude. Indeed the proper investigation of this branch of the oeolosy of the mountains would profitably occupy many months. Although little opportunity was presented for the systematic study of the central area of the mountains, such observations as were made in the northern portion of the range sustain the inference that the nu- cleal rocks are largely metar 1orphie. This is clearly the case along the west flank in the vicinity of Green River Cation, as also at Union Peak, and along the eastern flank, where these rocks are revealed in the mount. ain valleys of Little Wind River and the streams of the north, where- ever the latter were ascended beyond the limits of the unconformably superimposed Paleozoic formations. But with the meager data in hands, it would be impossible to attempt to define the lithologic and structural features of the rocks of this area, the successful elucidation of which would require a liberal allowance of time and facilities such as were be- yond our means of supplying. Along the mountain course of the tributary four or five miles north of Green River the gray banded gneissose ledges, associated with feldspar and talcose belts, have a general westernly inclination, the rock present- ing locally a brecciated appearance, with angular hor nblendic inelu- sions. The feldspar constituents weather into asoft, white earth, which may in part account for the milky discoloration of the waters, of the Green above the lakes. Ascending this stream to its sources in the summit plateau 8 miles south of Union Peak, the same gneissic rocks were still prevalent, the glaciated surface bringing out ‘the contorted lamination and ramifications of quartz and feldspar veins with which the rock is traversed. Just above a narrow rock-hemmed gorge, down 230 REPORT UNITED STATES GEOLOGICAL SURVEY. which the stream plunges, the schistose ledges curve over in an anti- clinal, on the east flank of which the inclination is 30°, + —. In the vi- emity a well marked porphyry dike appears on the north side of the stream, and may be traced at intervals to the ESE. and WNW., along its line of strike, a distance of a few miles. The dike is perhaps 100 feet across, and has a slight southerly inclination from the vertical ; to the east Mr. Perry reports it divided into three distinct branches, holding the same general course. In texture and lithology it’ varies from coarse mottled to dark green chloritic hue, weathering dark rusty, like trap. Its appearance is exactly similar to the dikes occurring in Mt. Hayden and Mt. Moran in the Téton range. On the summit of the range between the above-mentioned tributary of Green River and Campbell’s Fork of Wind River, knobby outliers of feldspathic granitoid gneiss rise above the plateau that here forms the summit. The rock weathers in blocks, recalling the granite knobs on the summit of the Laramie Range in the vicinity of Sherman Station, on the Union Pacific Railway. The gneiss, which is traversed by quartz veins, is represented by many varieties, including chloritic talcose and mica schists, the latter sometimes garnetiferous. The quartz veins have every appearance of segregated origin, resembling auriferous lodes ; but the gravel deposits of the west side streams revealed no gold. South of Green River Cafion the west flank of the mountain appears to be largely made up of a coarse feldspathic granitoid rock, the relations of which to the gneissic ledges was not ascertained; but judging from the evidence afforded by the erratic materials composing the great morainic ridges along this mountain foot the latter ledges must occur in the interior of the range. All along the east side of the Wind River Range, wherever we pene- trated to the Archean area, these rocks were found to be composed of gneissic and various schistose rocks, including hornblende, upon which the upraised Paleozoic formations rest, forming a more or less well- marked outer mountain ridge with escarped face towards the main sum- mitcrest. Union Peak, the most northerly eminence of the range, nearly 11,600 feet altitude, is made up of beautifully laminated and much con- torted gray, rusty-weathered gneissic ledges, including hornblende and mica schists, Showing a generai westerly inclination at variable angles. On the northeast shoulder of the mountain, a short distance from the summit, feldspathic granite appears in characteristic blocky exposures, identical with the knobs previously mentioned occurring in the plateau summit 6 miles to the SSH. Perhaps a couple of hundred yards south (2) of the peak a well marked granite dike, 30 yards in width, crosses a high shoulder of the mountain, strike about east-west, and dipping southwards at an angle of 45°, + —, which is inclosed between gray gneissic walls, similar to that forming the summit. The dike con- sists of flesh-colored feldspar with segregations of mica and quartz, the latter sometimes replacing the silvery mica as pseudomorphs. Five miles to the north, in the vicinity of the trail over Union Pass, low, rugged exposures of feld-spathic granite outcrop, forming the most northerly observed exhibitions of the nucleal rocks of the range. In the upper mountain basin of Warm Water Creek, above the cafion at Clarke’s Camp, placer mines have been recently worked. At the time of our visit the mines were temporarily abandoned, nor could definite information be gained as to the character and richness of the deposits. From time to time considerable prospecting has been performed in this vicinity, test-pits having been carried high up on the summit of the pass. Mr. Charles Blackburn, who accompanied the party, describes Plate XXIII. SE. (mag.) Green River Canon, above the lakes. Glacial-polished Archean ledges. Morainal ridges(a) debouchure Lac d’Amalia Cafion, west flank Wind River Range. Plate XXIV. c BA - ‘“ : cs ’ tale sr. JOHN.] WIND RIVER RANGE-—MORAINES AND SEDIMENTARIES. 231 the placer gold occurring hereabout as exceedingly finely comminuted and in consequence difficult to save by the ordinary processes employed in working the auriferous gravels. Fifteen to eighteen miles of the western mountain front north of the debouchure of Frémont’s Creek is denuded to the crystalline rocks, and the streams that flow down from the mountains, with the exception of Frémont’s Creek, which issues on the south line, are small and rise in the beforementioned Alpine bench. They all show wonderful exhibi- tions of glacial action in the rock-polished surfaces of t..e cailon-walls and the enormous quantities of débris built up into moraines outlying their debouchures. The latter materials are spread well out over the low slopes, effectually concealing from view the Tertiary deposits along the margin of the Green River Valley. Within this Archean west front lies one of the grandest cations, that by which Frémont’s Creek emerges, whose sources cluster about the mountain peak bearing the same name. This stream issues from the aforesaid Alpine bench, through a profound gorge hemmed in between precipitous glacial-polished walls of granite, its exit flanked by ridges of morainal origin a thousand feet and more in height. The minute description of these immense accumu- lations of morainie materials would require many pages; and while in the main features repetition is encountered along the whole mountain front, each debouching stream has something peculiar to offer in the dis- position of the erratic materials brought down by the great ice rivers and heaped up on or spread out over the plain. All the phenomena connected with the attained work of the glaciers is both striking and beautiful, and perh:ps no field in the west offers so favorable opportu- nity for the study of these phenomena as does that of the Wind River Mountains. Sedimentary border belts.—Twenty-one miles north of the south bound- ary of the district, Green River issues from the mountains at a point eighteen miles northwest of Frémonts’ Peak. Rising in the neighbor- hood of the latter peak, its mountain course is eroded hundreds of feet into the crystalline rocks which flank the gorge with precipitous glacial- polished walls scarcely inferior in height and grandeur to those that have rendered famous the scenery of the Yosemite. The cation was ascended a distance of six miles above its mouth, where the way was obstructed by the flooded condition of the few-yards-wide intervales, the adjacent rocks aliording no practicable trail. Four or five miles above the mouth a huge block of granite with nearly vertical sides and truncated sum- mit, rises on the south side of the stream to a height of perhaps two thou- sand feet. Below this mountain the valley expands, and is occupied by a pair of beautiful lakes. The upper and smaller lake is perhaps a mile in length and half a mile wide, its waters of a milky green from sedi- ment brought down by the main stream, and margined by low willowy bogs and flats. The lower lake, a mile or so to the northeast, is about twice the length of the upper, its half mile breadth of deep green water nearly filling the narrow valley. The contrast in the color of the water in the upper and lower lakes was very marked, as though all the sedi- ment had been caught and retained in the upper basin and the water pertectly filtered on its passage thence to the larger lake. A very interesting geological feature of this locality, and one which is So far as known unique on this side of the range, is the occurrence of a considerable remnant of Palaeozoic formations adhering to and lifted high up onthe mountain flank on either side of the debouchure of the Green. These great tables of seidmentary strata, in places flexed and shattered, present a peculiar feature in the topographical aspect of this ons REPORT UNITED STATES GEOLOGICAL SURVEY. part of the range and which is conspicuously displayed from long dis- tance to the southwest, west, and north. The area occupied by these rocks is probably included within a northeast-southwest belt eight miles long and not exceeding four miles in width, the bulk of the occurrences lying to the south of the Green where they also attain, perhaps, their greatest altitude. The outer mountain barrier crowned by these deposits is planed off level irrespective of the inclined position of the strata, a result attributable to glacial action. The nucleal rocks hereabout show gneissoid granite, the ledges more or less feldspathic and of a pale red color, at one point near head of lower lake dipping gently westward. Higher up the canon, the rock changes to a gray color, is laminated and mueh complicated by joint or cleavage structure. The mountain walls on either side of the entrance to the canon reveal the uplifted sedimentaries, which probably repre- sent the complete Palaeozoic series of the region. These consist in the first place, of typical exposures of buff, gray, and reddish stained ear- boniferous limestone and a buff hard sandstone, 2,000 feet or more in thickness, and which are apparently identical with the rocks composing the great ridge of Gros Ventre Peak that le twenty miles due west of this locality. Below the above ledge appears a heavy bed of grayish buff rusty-weathered magnesian limestone, 200 to 400 feet in thickness, and in all respects identical with the ledge elsewhere referred provision- ally to the Niagara epoch, although no fossils were detected in the rock at this locality. Below the latter otcurs a few hundred feet thickness of dark drab and gray rough weathered limestone, even-bedded and in places brecciated, resting upon a heavier series of yellowish-buff sili- cious beds, which probably are the equivalents of the Quebec and Pots- dam formations. The thickness of the sedimentary series above alluded to based upon rough estimates may not exceed 3,000 feet, of which two- thirds, perhaps more, belong to the carboniferous. The outer mountain declivity bears a heavy plating of carboniferous strata, the beds dipping north of west at an angle of 25° + —. On both sides of the caiion these deposits, together with the Niagara, are carried up forming escarped and peculiarly weathered mountain peaks or ridges. Between the lakes a sharp flexure arches the sedimentary formations, the axis of the fold being occupied by an Archean ridge that gradually rises to the south or southwest, in which quarter it was found to be quite denuded of the former rocks. Ascending the canon, east, the sedimentaries again rise quite uniformly or with gentle undulations, so that the lowest members of the series are carried to the highest ele- vations within perhaps a couple of miles above the upper lake on the north side and a less distance on the south side, beyond which the Ar- cheean is denuded over the remainder of the mountain plateau to the suminit. A low outflanking ridge lies close along the foot of the range, extend- ing from the great bend of the Green 10 miles south, where iv dies out in an uneven benched area. Beyond this point to the south line of the district the Tertiary deposits of Green River Basin impinge against the Archean mountain flank without intervention of older sedimentary for- mations. Throughout the greater length of the ridge the Triassic “ red beds” are displayed in frequent exposures in the slope descending to Green River, the interrupted section along this north-and-south line showing a broad, low undulation, in the axis of which Carboniferous lime- stones are br ought to view, as "has been elsewhere mentioned. In the benched area at the south end of the ridge the surface is broken by nu- merous sinks, the greater number of which are grassed over, although Plate XXV. S. 60° E. SE. (mag.) ; 5. 30° E. erie ee _— Entrance to Green River Canon. a Archean. b Paleozoic. d Moraines. om ‘SNOBDBIOID 2 ‘SULL-vIn pe Pp *SNOLOJIMOGIVD 9 “ULIINIIS Q ‘ueeyory 0 “UOURD IOAIY Wooly JO “AVG Soplu volyy UOTJDVG (ES aS ae AVIS 1, 1 aS farm ‘OOULY JOAN PULA, WML 4S Ay. VAT WI ‘SPAT 21}09A SOI pus ysray ‘sqisodup Teareaoyy ff ‘9}e19M0[SMOD por ‘AreMIOq, 2 ‘SUILL, P =. ‘“snoleyImoqiey 9 ‘URIINIIS Q ‘uvayaITy V MOUBD JOAIY Wood Opls YQALOM UOTQDG reSuLY JOA PULA ‘oyey aodd ‘OYV'T IOMO'T “Y100T “NT ‘IOATY Weal eoye[q Uweyory ‘SUIS¥G 01900 A S01X) pUL TOOTH) POYSIO} AA TIAXX 938d sr. JOHN.] WIND RIVER RANGE—JURA-TRIAS, &C. 233 some are apparently of recent date. Occasionally limited rock exposures are seen in the sides of the sinks, showing alternations of usually white to gray gypsum in layers from a few inches to 5 feet and more in thick- ness, and variegated reddish and drab clays and indurated layers. In the immediate neighborhood more or less extensive accumulations of calcareous spring deposits are met with, and at one point in the low bluff bordering the river intervale a copious stream issues from subterranean sources, its waters charged with mineral substances that render them unfit for use. One of the ancient spring orifices was examined, its di- mensions being about 50 yards one way by 30 in the other direction and 10 to 15 feet deep, portions of the calcareous tufa walls remaining quite perfect, as also the exterior limits of the deposition from the overtlow. The sinks occur-even on the opposite side of the Green, where one ap- parently formed only a few days before was seen close beside the road, the terrace gravel-walls forming its sides retaining their vertical position at the time it was examined. Their origin may be attributed tv the solvent power of water acting upon the gypsiferous beds, and where the latter deposits lie near the surface their removal may cause the super- jacent earth to sink into the cavities thus formed. Overlying the Triassic beds in the southern portion of the ridge are found a series of imperfectly-exposed Jurassic rocks made up of varie- gated pink, drab, and light-drab clays, and dark and light limestones. At a locality near the south extremity of the ridge the latter beds yield a few characteristic Jurassic fossils, Camptonectes, &c., by which their age is definitely determined. The deposits incline about southeast at an angle of 16°, the exposures belonging to the east or southeast declivity of the before-mentioned broad, low anticlinal arch. Pos ae Base Yooo ft.abwve sca leavel “3 as NE East flank Wind River Mts, : Section in Dry Creek Canon, Po an ah ‘yIOT OYV'T [Ng Suope aoroag ee WD Oe COUPES "TUN TI : LOSE Si = - > D, ; a es me z omy 0 eo 5 ane “LOATY PUM ‘OMT [ING TIXX P48 ‘[eUIBLOPY WwW “AIvA10T, (j) OA PULA 7 ‘AIVAIOT, ¥ *Sn090v}010 2 BINe Y ‘Stl, 6 ‘Moqiwo-ow1g / ‘OMO}SpULS “qaVgd a ‘OUO}SOMUTL “q1VyD p ‘seqan) a “tUUPSIOT Q ‘TvayLy Y “WOUB) YIOT OYLV'T [TMG APULIA “sap FOAL purA yup yseq | = Dees my a Saree "TIME ‘OVING JAVITT MOIS) “SO[POON OLYLTYSU AL TIXxX “48 (‘Svul) “WT “MN TIIAXXX 93e1d st. JOHN] BULL LAKE FORK CANON. 2AD5 fect exhibitions of the upper Carboniferous limestones and Permo-Carbo- niferous horizon. The small streams, of which there are four in this section, cut through the sedimentary ridge down to the Archean core of the range, revealing in their narrow gorges sections essentially like that last described above. Immediately along the foot of the mountain usually occurs a shallow parallel depression, in which the Triassic ‘red beds,” and farther out local exhibitions of dark drab and variegated Jurassic horizons appear, gently inclined to the northeast. The former deposits occupy a belt half a mile toone mile in width, and never ex- tend to any height on the mountain flank. Their junction with the sub- jacent Permo-Carboniferous is well exposed at several localities, the latter beds being charged with the characteristic little Lamellibranchi- ate shell, Plewrophorus. But the Jura is much less well exposed in this quarter. Indeed, the gentle grassy slopes intervening between the streams rarely showing later deposits than the thin coating of drift and soil that is spread over their surface, and here and there mesa-like rem- nants of the tufa-conglomerates. The main crest of the outer mountain ridge is formed of the lower members of the Carboniferous and the Silu- rian formations, which rise into elevations between 10,000 and 11,000 feet above the sea. Twenty miles to the southeast of Campbell’s Fork the great sediment- ary mountain ridge is again cleft to its base by the cation in which Bull Lake Fork flows. The latter stream rises high up under the precipitous wall of the great central crest of the range in the neighborhood of Fre- mont’s Peak, and flowing east-northeast joins Wind River, 25 to 30 miles distant from its ultimate source. Of its upper course, or that por- tion lying within the elevated rugged Archean area, little can be said from actual knowledge of the region. It is not, however, an inaccessi- ble region, and to the lithologist and mineralogist it offers an absolutely new field of research. Along its lower course it has eroded a broad canon-way walled by characteristic cliff exposures of the Paleozoic for- mations, which on the south side rise up into heights above 10,800 feet actual altitude. At its exit from the mountain the stream flows in a narrow valley hemmed in by high bluffs capped by enormous morainal accumulations that extend to Wind River, eight miles away. Just be- low the debouchure the stream expands into a lake between two and three miles in length, its indented shores bordered by sage-covered slopes and fringed with cotton-woods and willows. Mr. Clark’s barometrical observations give the water-level of Bull Lake an altitude of 5,911 feet above the sea. The immediate mountain-foot in the debouchure of Bull Lake Fork is composed of the upper members of the Carboniferous series. In the blufis bordering the stream in its passage across the outlying benched area, late continued erosion, fortunately, has swept off the superficial materials and barred one of the most complete sections of the Mesozoic series to be met with in the northern half of the range. Besides the Paleozoic series shown in the lower cafion walls, where their general characteristics were hastily glanced over, we here have the Mesozoic formations displayed under exceptionally favorable conditions for detail stratigraphic study. This whole grand series of geological formations from the Primordial up to the upper member of the Cretaceous of the region, are here revealed without slightest indication of discordance of deposition of more than local significance or such as a stratum of any subordinate member may be expected to show. But during the Post- Cretaceous time the duration of these conditions was interrupted, and the evidence is legibly recorded in the unconformably superimposed Cenozoic deposition here met with. 246 REPORT UNITED STATES GEOLOGICAL SURVEY. Section on Bull Lake Fork. No. 1. Archean. No. 2. Primordial quartzitic sandstone. No. 3. Quebec limestone formations. No. 4. Buff or drab reddish stained limestones, apparently fonning a distinct horizon underlying the buff magnesian limestone, as seen in the great cliff exposures in the cafion walls. This limestone holds the hori- zon of the Niagara, but it is regarded as probably belonging to the Car- boniferous. No. 5. Carboniferous magnesian limestone, 300 feet, +. No. 6. Drab and gray rusty-weathered limestones, more or less cherty, with magnesian layers 400 feet +. Contains characteristic Carbonif- erous fossils, and is here referred to the lower division of the series of which it forms the upper member. No. 7. Middle Carboniferous division, light gray, reddish buff, weath- ered, even-bedded sandstones, 400 feet, +. No. 8. a, buff or light-gray limestones, with occasional shaly layers and bands of chert, with calcite and gypsum, 40 feet, +; b, chert band with fibrous gypsum, 4 feet; c, gray limestone, with cherty layers in middle containing nodules of chalcedony with a black bitumen min- eral and calcite geodes, 15 feet, +; d, dark and light-gray limestones, cherty and nodular, alternating with shaly layers, with a 6-inch layer charged with black bitumen or carbonaceous matter, contains obscure fossils, 15 to 20 feet ; e, gray limestone, with calcite, 8 feet. No. 9. Drab clays and brown indurated shales, 50 feet, +. No. 10. Gray magnesian (?) limestone, with calcite 15 feet, +. No. il. a, gray nodular limestone with clay partings, and chert, nu- merous fossils of same species occurring in No. 14, 35 feet, + ; b, blue nodular limestone and shales underlaid by indurated dark drab calea- reous Shales containing cavities lined with calc. spar, 40 feet, +. No. 12. Chert band, made up of uneven layers, 8 feet, +. No. 13. Gray limestone, in places brecciated, with flint nodules, con- tains Chetetes (?) Bryozoa, &c., 20 to 30 feet. No. 14. Permo-Carboniferous horizon; a, light-drab clays with nod- ules of fiint and calcite, and thin layers of gritty brown and gray lime- stone containing casts of a small Plewrophorus, Bakevillia, &e., and in lower part thin irregular layers of limestone alternating with clays con- taining numerous fossils, Productus costatus ? P. punctatus (2) Spirifer, two species, &e¢., 65 to 70 feet; b, gray, thin-bedded, gritty limestone, more or less coneretionary and magnesian (?) with ripple markings, 25 feet + ; dip 15° to 20° northeast. No. 15. Light-drab clays with thin indurated layers, imperfectly ex- posed, 30 to 50 feet. No. 16. Triassic red sandstones and arenaceous shales, with thin gray sandstone layers 1,000 to 1,400 feet; dip to the northeast, and at angles of 15° to 20°. No. 17. White gypsum, more or less regularly bedded, including one or two thin layers of sandstone, the outcrop somewhat fractured by ten- dency to joint structure. This bed shows a thickness of 25 to 40 feet, forming the crest of an outlying spur-ridge in the north side bluffs, some distance above the head of Bull Lake. : No. 18. a, red, greenish, and chocolate-colored shales with thin layers of white gypsum, and gray and drab indurated layers; b, red and gray banded shales, the outcrop presenting a beautifully variegated band wherever seen, 100 feet, +. No. 19. Drab, fragmentary limestone, 6 feet, + ; dip 23°, N. 42° H. Plate XXXIX. SW. (mag.) W.SW. S.SW. Sta. XXII. ease he AE na bee Be Ba a er eR ‘ Se Ga ——S Sn \, Ron S Pty Silay Soe Lott, SS SOS ! s SS See ae ————— Hef, Wiha — = eee E ‘ PR ao <*> >- f Apa RL Wh we ae an aS Ge ine? 2) 7 a Archean. c Quebec. d Carb. limestone. e Middle Carb. sandstone. f Glaciated metamorphic ledges. g Morainal deposits. i ec ie “is i ~ ae a oi ave st. JOHN.] MESOZOICS—BULL LAKE FORK. 247 No. 20. Drab shales, 15 to 20 feet. No. 21. Dark gray fragmentary limestone, with obscure remains of fossils, 1 foot, +. No. 22. Drab clays with lamine of calcite or gypsum, 15 to 20 feet. No. 23. Dark gray fragmentary limestone, 4 feet, +. No. 24. Drab shales with thin beds of light-gray sandstone, 170 feet, +. No. 25. Gray, buff weathered soft sandstone, in part thin-bedded, with soft flagging layers, forming mural exposures in crest of spur-ridge, showing a thickness of 20 to 30 feet, dip 19° to 239, N. 42° HK. Upper layers contain casts of several Lam llibranchiate shells, probably rep- resentatives of Jurassic forms. No. 26. a, red and drab shales, alternating; b, pale-red shales; ¢, chocolate-red shales and thin sandstone layers, alternating. This hor- izon presents a beautiful variegated belt in the steep slopes of spur- ridge, and probably attains a thickness of 300 feet, +. No. 27. Soft-white or light-buff sandstone, 10 to 15 feet. No. 28. Light and chocolate-drab shales, banded with thin indurated layers resting upon red shales, 250 feet, +. No. 29. Buff sandstone, forming a heavy ledge in crest of spur-ridge, 25 feet, +. : No. 30. a, alternating layers buff sandstone and drab clays, with fu- coidal (?) impressions, 20 feet, + ; b, brownish-drab shales, with sel- enite ; ¢, banded brown, yellow, blue, and dark, gritty shales and thin sandstone layers, 200 feet, +. No. 31. Rather firm, light-gray, buff-weathered sandstone, 5 feet, + ; dip 18° N. 23° HB. No. 32. Dark-drab and bluish shales with selenite and thin bands of efflorescence, and in lower part a dark fragmentary calcareous layer perhaps 2 feet thick, 400 feet, +. No. 33. Shaly and concretionary, fragmentary, dark-blue limestone, 5 to 10 feet. Contains fragmentary remains of Teliost fish-scales, &c., re- sembling and probably identical with forms elsewhere occurring in the Colorado group of the Cretaceous. No. 34. Drab clays and thin indurated layers, containing fish remains like those in No. 33, 110 feet, +. No. 35. Rusty weathered, gray sandstone with clay partings, 60 feet, +, exposed in bluffs about opposite the head of Bull Lake. Locally shows the following subdivisions: a, at base bluish-gray sandstone, 5 feet exposed; b, space with drab shales, 15 feet; c, thin-bedded gray sandstone, 5 feet; d, space, 15 feet; e, bluish-gray sandstone, 5 feet, +; fp brown shales, 5 feet; g, gray sandstone with fucoid-like markings, 10 eet, -. No. 36. Rusty-yellow sandstone, and sandy and brown gritty shales, dark flint nodules in upper layer, 30 to 40 feet. No. 37. White, very fine clays, 8 feet, +, forming a conspicuous band in the bluff exposures. No. 38. Drab shales with layers of rusty sandstone below, selenite and white efflorescence above, 30 feet, +. ; a 0. om Yellow buff, soft sandstone, heavy bed, dip 15°, N. 42° H., 80 eet, +. No. 40. Light-drab clays with white efflorescence, imperfectly exposed, 40 feet, +. No. 41. Light-gray, thin-bedded sandstone, 6 feet, +. No. 42. a, Light-drab clay, with white efflorescence ; b, banded dark- drab clay, with brown carbonaceous, shaly bands; c, light-drab sandy clay. .175 feet, +. 248 REPORT UNITED STATES GEOLOGICAL SURVEY. No. 43. Brownish-gray sandstone, thin layer. No. 44. Bluish arenaceous clays, with thin, indurated layers, 300 feet, +. No. 45. Soft, bufi-gray sandstone, dip 15° N. 520 B., 30 feet, +. No. 46. a, veddish-drab and brownish clays; 0, lignite coal, 8 to 1 inches, drab clay 12 inches, lignite 3 inches, drab clay 12 inches, lignit 6 to 10 inches, total 4 feet ; 6, brown clays with selenite, 15 feet ; “total feet, +. No. 47. soft, light yellow sandstone, 20 feet, +. No. 48. a, soft, “erayish yellow, shaly sandstone and brown clays, ex- posed 10 feet; 6, drab-brown shales, with minute flakes of mica and sel- enite, 3 feet; C, brown, gritty shales, with selenite, 30 feet, + ; total, 60 feet, ==. No. 49. Rusty brown and buff calcareous sandstone, 8 feet +, with nu- merous fossils In upper part, Inoceramus and several other conchifers, gasteropods, and Ammonites, probably identical with Fox Hills Creta- ceous forms. No. 50. Soft, yellowish sandstone and clays, imperfectly exposed, and belonging to a heavy bed at the top of the Mesozoic series here exposed. No. 51. Tertiary. Buff sandstones with more or less argillaceous mat- ter, resting unconformably upon the preceding sandstones, No. 50, in nearly horizontal strata. : No. 52. Yellowish clays, slightly brownish or reddish tinted above; possibly Pliocene or Post-Tertiary. No. 53. Morainal bowlder deposits crowning ridge 800 feet anare the level of Bull Lake. The few hours devoted to the examination at the above locality neces- sarily left the results less complete than could be desired. It is impos- sible to draw the line of demarkation between the Jurassic and Creta- ceous horizons, also between the former and the Trias. In the latter case, however, the great gypsum deposit affords a convenient horizon, but since this is evidently an excessive local development it might not subserve*even the purpose of convenience. A comparison of this part of the section with the equivalent horizon to the northwest exhibits a marked change in the lithology of the inter-Jura-Trias strata. We here lose entirely the well-developed yellowish or buff sandstone that occurs in this horizon at the confluence of North Fork and Wind River, although - the lower limestones correspond stratigraphically with occurrences at that locality, except for the paucity of organic remains in the present beds. It is hardly necessary to add that not the vestige of an organism was observed in the characteristically ‘red beds” of the Trias. The Jura, however, is recognized in the fossils occurring in the sandstones No. 25. But the limits of the formation above in the present state of knowledge must be arbitrarily assigned to some one of the lithologically conspicuous horizons interposed between No. 25 and No. 30. One or more of the sandstone and shale horizons occupying this space may prove to be identical with the Dakota or inferior formation of the Cretaceous. The heavy clayey measures No. 32-34, inclusive, doubtless represent the middle or Colorado group, while in the upper portion of the remainder of the conformable deposits, extending up to No. 50 and embracing a vertical thickness of strata probably in the neighborhood of 900 feet, a stratum occurs charged with a molluscan fauna ‘eminently characteristic of the Fox Hills division of the Cretaceous series. The lithology of these upper strata alone would strongly suggest the above inference. Although not a unique occurrence, the presence of lignitic deposits in these undoubted upper Cretaceous rocks at the present locality i is an in- Plate XL. ons, north si Plate XL. East foot Wind River Mts. Bull Lake. Morame =—— = ‘ : > : 2S. Scale 1O00ft to the inch oa A " Cretaceous. (15407 -) 3 Section of Upper Carboniferous, Mesozoic, aud ‘Vertiary formations, vorth side of Bull Lake Fork, ‘OHR] ONY OAOQE ‘7717dn UIE TNONT 07 OSIBASTP.A} OTOJSPULS SHOATIMOG. eA UL SMOTY[NpUN SuLMoYg “UOUBD FLO oOYL'T [[M_ Jo oanyonoqop Ur Wolyoag “OULVIOFL “SOUIVIO TL 9 “AIVYI9T, Q ‘(80d [ITA ‘SNOVDBJOID ‘IMRT [LUG PE. jar we 24 5 TIX 97eid ST. JOHN.] WIND RIVER RANGE—SAGE CREEK CANON. 249 teresting fact, and deserves to be thoroughly investigated with the view to determining their economic value. The Palzeozoic series exposed in the walls of the Bull Lake Fork cafion is of no less interest in a geological point of view. But for want of time only the upper member of the Carboniferous was studied with any pretension to minuteness. Of the latter member, including the uppermost and dis- tinctively Permian horizon, the foregoing section exhibits the detail stratigraphy with close approximation to the truth. The full thickness of the strata lying between the great sandstone of the middle division of the Carboniferous, No. 7, and the base of the Triassic “red beds,” No. 16, reaches a maximum of about 400 feet, of which the Permian or Permo- Carboniferous horizon comprises the upper 120 to 150 feet. The fossils of the lower strata of this upper series belong, in the main, to character- istic upper Carboniferous types. Their absence in the uppermost strata, in which such forms as Pleurophorus and Bakevillia exclusively occur, presents a striking faunal contrast to what obtains in the lower beds, and one that unmistakably indicates in this remote quarter a state of things analogous if not identical with what prevailed at the close of the Carboniferous period in the Mississippi basin along the western border of these occurrences in the States of Kansas and Nebraska. Just within the lower entrance to the cation of Bull Lake Fork a sin- gular low ridge spans the valley, through which the stream has forced a wide passage. It is made up of the middle Carboniferous sandstones whose tilted edges are presented in an abrupt bluff barrier facing up the valley, the opposite side, which is flagged with the overlying limestone, declining more gently with the dip of the strata. The abrupt bluff-face of the ridge gives a section of the sandstone along a line closely corre- sponding to the strike of the strata, in which are revealed some interest ing minor undulations, as though the beds had been crumpled by a force acting laterally, but which is probably attributable to slight inequality in the intensity of the vertical movements that forced the strata up into their present inclined position on the flank of the mountain. Mr. Perry observed similar phenomena, though on a much larger scale, in the up- lifted Paleozoic formations in Jake’s Creek Cation, where the strata are described as having the appearance of a low fold transverse to the mountainupheaval. Inregardto the Bull Lake Fork locality, it is difficult to account for the existence of the sandstone barrier, which has main- tained itself in spite of fluvial and glacial erosion to which it has been exposed for ages. The mountain flank between Bull Lake Fork and North Fork Little Wind River, 10 miles to the south, is gashed by the drainage of Sage Creek, whose sources, to judge from the character of the erratic materials swept down by the stream, scarcely penetrate to the Archean area. This little stream debouches from a narrow caiion in the middle Carboniferous sandstone and overlying limestones, the upper course of the stream being defined by the earlier members of the series which, in the summit of the ridge, attain altitudes between 9,000 and 10,000 feet above the sea. The Carboniferous sandstone and dark-wreathed fragmentary limestones everywhere appear in the grassy slopes along the foot of the mountain, the edges of the various upraised geological members breaking down in abrupt declivities facing the great inclined planes in which the outer slope rises over successively lower formations until it culminates in the crest overlooking the Archean area. The summit of the mountain ridge is formed by the Silurian limestones; to the north the lower member of the Carboniferous or so-called Niagara magnesian limestone may constitute the coping ledge. The latter horizon is often weathered in picturesque 250 REPORT UNITED STATES GEOLOGICAL SURVEY. cliffs and huge outlying masses in the slopes a few hundred yards below the summit, while the outcrop of the Potsdam sandstone is traced here and there in the débris-covered inner slope descending to the Archean basis rocks, rounded elevations of which still retain isolated remnants of the Primordial strata. The Triassic “‘red-beds ” appear over an outlying parallel belt, half to three- quarters of a mile wide, forming picturesque highly- colored low bluffs bordering the little valley below the debouchure which widens out into the basin through which the stream winds lower down. . 7% 4 5 mie = = Base 6000 Nav SOE ToD TCE) SSS efrgrik Section vicinity of Red Canon, NW. of Campbell’s Fork. 1. Middle Carb. sandstune. 2-11. Permo-Carb. 12. Trias. 13. J.-T. Passage beds. 14. Jura, &e. (a-k). 15. Wind River Tertiary, &c. 16. Tufaceous limestone and conglomerate. East flank Wind River Mts. Wind River Basin. Section north of Sage Creek. : 1. Archean. 2. Potsdam. 3. Quebec. 4. Niagara (?) magnesian limestone. 5. Carb. magnesian limestone. 6. Carb. limestone. 7. Carb. sandstone. 8, Permo-Carb. 9, Trias. 10-12. Jura, 13-17. Cretaccous. 18-20, Tertiary (?). 21. Pliocene (?) conglomerate. « Spoq pot,, sissvrry, 6 ‘qivy-omleg f *SOUICIOT 2 *07V.1OMIO[SU09 (j) OMBDOITT Y “OUO}SpULs “qIVy a *sUOJSOMUT[ “QIVy p OAL PULA\ O[}IUT FLO. [ION wo tourg “UveBypory TITTX 97%id IXX "WS “AAS iad st. soun.] LITTLE WIND RIVER CANON. 251 the basin Tertiary series described in following pages under the head of Wind River Basin. No. 21. Pliocene, or possibly Post-Tertiary, conglomerate, resting upon the planed-off edges of the unconformable subjacent Mesozoic strata, attaining a thickness of 30 to 50 feet, gently sloping in the direc- tion of the basin. The deposit is here mainly made up of water-worn limestone and sandstone pebbles, evidently derived from the adjacent mountain, few, if any, metamorphic fragments occurring in the deposit, which is more or less firmly cemented. This deposit reaches well up on the outlying slopes, in places resting upon the Trias. The Tertiary and Post-Tertiary occurrences briefly alluded to in the foregoing section in the vicinity of Sage Creek, are further mentioned in the chapter devoted to the consideration of the Wind River Basin deposits. The fossiliferous Jurassic sandstone, No. 13, is an interesting occurrence, definitely establishing the age of the series of variegated arenaceous and argillaceous strata with which it is associated. It is impossible in the present lack of paleontological evidence bearing on the question to de- cide where the line of demarkation between this series and the Triassic should be drawn. It is probable, however, that the upper limestone, No. 10, pertains to the Jura, in which case the inferior buff and reddish sandstones would fall into the horizon of the passage beds, offering a some- what marked resemblance to the lithologic appearances remarked in this horizon in the region above Campbell’s Fork. The upper member of the Cretaceous was not recognized at this locality, the uplands lying to the east of the Colorado shales, being occupied by the Pliocene (?) conglom- erate formation which masks the older strata upon which it rests. Little Wind River debouches from the mountains a little north of the parallel 43°, opening a wide gap across the sedimentary plated mountain ridge, exposing to view an exceedingly rugged Archean region outlying the main erest of the range at the heads of both the North and South Forks, as seen from the valley near Camp Brown. Just without the foot of the mountain the main stream forks, each branch penetrating the in- terior of the range independently, and where they break through the outer mountain ridge their courses are confined between stupendous walls, which disclose magnificent sections of the upraised Paleozoic series from top to base. In the latter respect, as also in the scenic con- comitants, the Little Wind River cafions are much like those men- tioned in preceding pages, yet with local peculiarities sufficiently strik- ing to arrest the attention and stimulate the desire for more intimate acquaintance with the locality. The canon of the South Fork, which lies mainly south of 43d parallel, appears to be the narrower of the two, though the mountain basin in which their sources lie is much the same. About three miles above the debouchure of the North Fork the stream is confined to a narrow defile hemmed in by steep débris slopes terminated above in vertical walls of Carboniferous limestone. This part of the valley is swept nearly clean of the morainal deposits, whose recurrence above and below exhibits some of the most stupendous and interesting examples of their kind. Above the narrows the sedimentary cliffs diverge to right and left, rising up into the crest of the ridge which here, as to the north, forms a rim defin- ing the Archean area of the elevated interior of the range. At the en- trance to the canon below, the Permo-Carboniferous and upper lime- stones outcrop in the low benches alongside the stream, but no good exhibitions of the junction with the Triassic “‘red beds” were met with. Underlying these deposits, which incline at an angle of about 12°, N. 52° E., the middle Carboniferous sandstone formation appears, gradually 252 REPORT UNINED STATES GEOLOGICAL SURVEY. rising on the mountain flank; but immediately bordering the valley on the north side, to which the present examinations were confined, it has been much eroded and heavily loaded with morainal deposits which reach high up on the mountain foot in the debouchure. In the opposite side, however, this horizon is well displayed together with its relations to subjacent formations. About opposite the narrows a sudden flexure or up-bending in the lower limestone formations takes place, where the strata are tilted at a high angle, the tension accompanying their abrupt displacement manifesting its intensity by the rupture and faulting of certain beds, while the continuity of other and less refractory strata was unaffected. As seen from the summit of the ridge, looking down along the mountain flank to the north, a slight undulation in the declining strata was the only evidence of the continuation in that direction of the flexure which forms so marked a feature in the cafton-walls. Above the flexure the strata resume their former moderate inclination thence to the summit of the ridge. This highland region abounds in excellent pastur- age, and along the streams considerable tracts of mountain meadow are met with. The rugged slopes are well stocked with evergreen forests up to a line nearly corresponding to the altitude 11,000 feet above the sea. After leaving the mountains Wind River flows through a broad fertile valley, in the midst of which Camp Brown and the Shoshone Indian Agency are located. The altitude at the debouchure of North Fork is about 6,730 feet, the stream descending to 5,700 feet at the military post, in a distance of about twelve miles. The north side of this valley is bounded by the outlying uplands which break down in grassy declivities, in which the geological formations are in the main concealed from view by the loose soil. Here and there, however, over comparatively limited areas, the component strata crop out, and with care a detail section might possibly be made connecting the basin deposits with those more clearly shown along the foot of the mountains. Two or three miles below Camp Brown, and perhaps twelve or fourteen miles distant from the mountain foot, there appears an anticlinal fold with indications of a sharp synclinal on the west flank, which has brought up a series of variegated arena- ceous and clayey deposits which, lithologically, bear striking resemblance to lower horizons occurring in the Jura of this region. On the west slope of this anticlinal the occurrence of drab fragmentary limestones, red and drab clays, and soft buff and grayish sandstones are certainly more in concordance with the stratigraphy of the Jura than with that of the Cretaceous members met with farther north, as described in fore- going pages. At the locality examined the axis of the sharp synclinal fold is occupied by an apparently heavy deposit of reddish and drab clays with associated sandstones, to the west of which obscure exposures of drab clays and soft arenaceous deposits, inclining eastwardly, seem to merge into the dark drab Colorado shales that appear in their proper stratigraphical order in the upland bench rising up against the foot of the mountains. The broad, shallow depression through which the Sage Creek drainage seeks Little Wind River marks the axis of the anticlinal fold, in the crest of which is located the bitumen spring which was described by Dr. Endlich in the Report of the United States Geological Survey for the season 1877. The flow of water is feeble, bubbling up in several hardly discernable vents, around which the bitumen is deposited, forming sheets whose consistency in the margin of the overflow becomes the hardness of an asphalt pavement. The spring is slightly raised above the general level of the plain, averaging perhaps 50 yards in diameter, and is par- tially overgrown with tall grass. Birds and small Indians, frequenting the place for water and sport, not infrequently become entangled and Se Plate XLIV. SS ig <2 7120leS > Lateral moraines debouchure Bull Lake Fork. Red Canon . oO, EL ee Lateral moraines debouchure Campbell’s Fork. LF —>. Fae 6000 Section north side debouchure N. Fork Little Wind River. xa pa sctatytghnt Catel tetas ie EAST FLANK OF WIND RIVER RANGE, FROM CAMP BROWN. 4 NW. Stes XX1TXX. Sie SRI. Wind River Bastre. sw. SS swan eee bea 2 2 whoeawn. Cc Stlurtarn. d.Carboniterous. g. Tréiassic’red beads. h. SUras ste. 1. Cretaceoatts (®/ ke. Tertiary. mw. Moratnes. a. Archeoed . : c ‘Y SECTION VICINITY OF NORTH FORK LITTLE WIND RIVER. HAST FLANK Wind RIVER Mrs. BASIN FOLD. Sta, XX, Camp Brow. Bitumen Sprin q- mo00tt. = i [Base F000 fa above sea tee ee Ss —— LArchoean. 2. Potsdam. 3. @uchec. 40. Magirestan limest. GO. Carb. limest. 7. Carbontherous lmest. =o Th : ; : ‘ ; 8. Permo~ Carbonth GI. Trias. 10. Sure. M7. Cretaceous (2) 12-24. Strata tnvolwed in Basin Hold. 25 FPlioceme (2/ con glomerate . 26 Moraries Plate 45. set hiteat Vitalin a i eal fi Novas \ : Bund t f pa lat : ef) 4 i hy wok, PN aim dey Toh to a iby My cai : : i y iu . i Hi ae ORK! i é : My ( Le ‘sd : a.Archoean. Cc Stlurtare. a. Carhort, SECTIO] HAST FLANK. WIND RIVER MPs SIGCHI V 000 TE. [-—__—— e r LArehoa, 2 Potsdanr.~ FACE BP LES: TO. Stra. LL, Cretaeceows | 5 : ST. JOHN.] SECTION ALONG LITTLE WIND RIVER. 253 besmeared in the soft, viscous substance. On the east side of the de- pression the successive ranges of low, parallel bluffs that appear farther out in the basin show sandstones and variegated clays, and finally a heavier mass of brownish drab clays, all dipping gently eastward. The latter deposits may be identical with the Colorado group. The above- mentioned anticlinal was traced but a few miles to the north of Little Wind River, but to the south, where it was examined by Dr. Endlich during the previous season, it assumes a more important topographical position, where its geological structure may be studied under less unfavor- able circumstances than those attending its exhibition in the present uarter. : The geologic section in the vicinity of North Fork of Little Wind River is given below, together with notice of the few observations made in the basin area to the east, supplemented by the diagram illustration of an accompanying plate, with which closes the account of the too briefly exe- cuted observations in this important mountain range. Section vicinity of North Fork of Little Wind River. No. 1. Archean. Mainly schistose rocks. No. 2. Potsdam. Coarse-grained, grayish-buff, reddish-stained, in places of a dark-red color, thin-bedded sandstone, with oblique laminated layers, and locally quartzitic. The greatest exposed thickness of this ledge probably does not exceed 50 feet, but it is probably much thicker. Its contact with the metamorphic rocks was not revealed, and the nature of the overlying deposits, which readily yield to atmospheric erosion, are not conducive to the exposure of the full vertical extent of the horizon. In the isolated outliers crowning the heights north of North Fork drain- age, the beds incline about N.57° E., at an angle of 10°. No. 3. Quebec. Ledges of drab, fragmentary, thin-bedded limestone, showing mural exposures of 10 to 25 feet at top, where at one point it appears in the summit of the mountain ridge, showing a heavy bed of drab-gray, yellow-mottled, even-bedded limestone, with brecciated and odlitic layers, containing fucoid-like markings in relief, in form also re- sembling certain ramose forms of the coral Chetetes, and the glabella of a large Trilobite. These occurrences, which are separated from the pre- ceding sandstone, No. 2, by a space probably occupied by shaly passage- beds, are met with in a vertical space not exceeding 400 feet. The ledge in the summit of the ridge dips 10°, N.52° E. The horizon appears in a long line of rusty-weathered mural exposures in the escarpment on the south side of the cation. The lithological character of the rock is pre- cisely that of equivalent strata met with in the Gros Ventre and Téton Mountains, as also on the west flank of the range in the neighborhood of Green River Caiion. No. 4. Buff-weathered maguesian (?) limestone,in places, forms a rather well-marked ledge, 75 to 100 feet +, exposed, and holding the position of the so-called Niagara dolomitic horizon. No evidence, however, was gained by means of which to satisfactorily determine its age. The above ledge is, at least, locally separated from the preceding by slopes over soft dirty-buff deposits. No. 5. Carboniferous. Grayish-buff, rough-weathered, heavy-bedded magnesian limestone, with small jasper nodules and iron concretions, weathered in castellated shapes and forming a prominent ledge in the escarpments either side of the cation, 200 feet, more or less, in height. Contains Zaphrentis, crinoidal fragments, Bellerophon, &c., apparently referable to Carboniferous forms. 254 REPORT UNITED STATES GEOLOGICAL SURVEY. No. 6. Drab and gray limestone, forming a heavy deposit several hun- dred feet in thickness, as seen in cliffs on the south side of the cation. No. 7. Buff-gray sandstone, with obliquely-bedded layers, exposed in — the lower escarpments, especially on the south side of the canon and in adjacent mountain flank, 300 feet +. No. 8. Upper Carboniferous limestones and Permo-Carboniferous hori- zon, the latter showing at one place in the debouchure of the cafion, below: Light-gray, in places, magnesian limestone, 5 to 10 feet exposed ; dark-gray, shaly sandstone with silicified fossils, exposed 4 feet; drab and dark-gray, compact and porous, thin-bedded limestone, exposed 5 feet, containing numerous casts of a small Plewrophorus, besides a large Bellerophon, &e.; light-gray, thin-bedded cherty limestone. No. 9. Triassic ‘“‘red beds,” composed of deep-red shaly sandstones and arenaceous shales, and reddish-buff or gray soft sandstone with ripple-markings. The exposures in the bluff just without the cation show a thickness of several hundred feet (700 to 1,000) of this horizon, the strata dipping at an angle of 139, N. 27° to 42° H. No. 10. Jura. Variegated pale-reddish and drab deposits, as seen at a distance in obscure exposures occurring in grassy Slopes. These deposits occupy a wide belt outlying the Triassic “red beds,” and may reach a thickness of 1,000 feet. No. 11. Cretaceous. Dark-drab (clays), and above light-buff (sand- stones and clays) deposits appearing in more or less distinct belts lying beyond the preceding, and probably including the Colorado and Fox Hills members of the series. No. 12. Drab clays, in bluff north side of Little Wind River, just below Camp Brown. No. 13. Greenish-gray, coarse-grained, rather friable sandstone, with layers of reddish-brown weathered firmer sandstone, associated with red- dish-drab clays and light-drab indurated clay shales. The above deposits outcrop in low, upland declivities to the northeast and 200 feet above Camp Brown, where they incline to the northeast at an angle of 30° to 34°. The sandstone contains partially silicified fragments of fossil wood. No. 14. Soft buff sandstone, dip steep to the northeast. No. 15. Reddish and drab clays. No. 16. Drab fragmentary limestone, 5 feet +, dip 70°, SW. No. 17. Red shales and soft sandstone. No. 18. Gray and yellowish, cross-bedded, soft sandstone, 50 feet +, dip 40° northwestward. No. 19. Reddish and drab clays. No. 20. Drab fragmentary limestone, exposed 4 feet. No. 21. Greenish-gray, reddish-stained, soft sandstone, associated with red and drab clays, dip 419, W. 52° N. No. 22. Soft, greenish-buff, reddish-stained sandstone, and red arena- ceous shales, exposed 50 feet +, dipping gently northeastward. No. 23. Gray sandstones, as seen at a distance, in low blufis. No. 24. Heavy deposit of drab clays and indurated layers, compared with the Colorado group of the Cretaceous, appearing in “ bad-iand” bluff slopes. No. 25. Loosely compacted conglomerate, consisting of rounded Ar- chean bowlders and pebbles, with local thin layers of soft buff sand- stone, the general appearance of the exposures showing obscure strati- fication, nearly horizontal, deposited upon the eroded edges of the in- clined Mesozoic formations and reaching up nearly to the mountain foot. Compared to modern or possibly Pliocene accumulations. It is over- spread with later morainal deposits. No. 26. Morainal deposits. . at = = ae SFG aC a Py ae i Plate XLVI. SS) TSS we BuO Wi) SS +) x OL Aa gy! Ys 4 f Ae) ne i el Bb o4 aac 2 ae sO NE ee yee tit) yds sede Ip RUS Eir 3: fA i. Y f C 2) : a 4 Ae “caf a ete ~ H SEAM Wind River Valley. Statue Butte. Sierra Shoshone, NW. Togwotee Pass. Clover flats. Source Wind River. Volcanic tuff, sands, breccia, and conglomerate. CHUA RU EAT WV. TE WIND RIVER BASIN. Area and.surface features.—The region drained by Wind River and its afflnents opens out to the eastward in a gradually expanding wedge- shaped area, the greater portion of which lies beyond the limits of the district assigned this division of the survey. The main stream rises in Togwotee Pass, whence it flows in a general east-southeast direction, a distance of about 85 miles, to its confluence with Little Wind River, at which point its course is suddenly deflected northwards, and is thence known as the Bighorn River. Orographically the basin is defined on the southwest by the Wind River Range and on the north by the great voleanic ridges of the watershed reaching eastward from Togwotee Pass, and which are continued in approximately the same direction in the lower highlands of the Owl Creek Mountains ; to the southeast the basin area merges into that properly belonging to the Bighorn drainage. The region above outlined has in years past been visited by various expeditions conducted under the auspices of the United States War De- partment, and to the published reports of these explorations we owe the most authentic accounts of its general topographic and geological feat- ures. Dr. Hayden, who accompanied the expedition in charge of Capt. W. F’. Reynolds, Engineer Corps, U.S. A., in 1859, has given account of its salient geologic structure, and Prof. Theodore Comstock, of Capt. W. A. Jones’s expedition to the Yellowstone, 1873, has elaborated the same theme. The actual geological examinations performed by this division of the survey within this basin area were chieily confined to a narrow belt immediately along the southwest border, or lying between Wind River and the mountain range bearing the same name. The latter work was carried from Togwotee Pass at the head of the valley southeast- ward to the eastern boundary of the district and beyond as far as Camp Brown, at which latter point the observations connect with those made by Dr. Endlich the previous season in the district lying to the south of the parallel 43° and east of the meridian 109° 30’. The greater portion of the basin is thoroughly watered by numerous streams that rise in the bordering mountains, its terraced valleys and upland plateaus being generaily clothed with nutritious herbage. In the lower portion of this area, however, more or less of its surface falls under the head of “bad lands.” Its general surface lies at an altitude 5,000 to 7,000 feet above the sea; the lower valleys in favorable seasons yielding abundant crops of cereals and vegetables, while the greater portion of its extent is valuable for grazing purposes. The larger part of this extensive and beautiful region is included in the Shoshone Indian Reservation, which extends up the valley from Little Wind River west, to the mouth of North Fork, and stretches north-south, from mountain to mountain. Geological features.—-In that portion of its course lying within the pres- ent district, Wind River flows close along the foot of the southwest bor- 255 256 REPORT UNITED STATES GEOLOGICAL ‘URVEY. der range, the lands on the north rising in great up wd benches that occupy the wider interval lying between the main stre m and the mount- ains on that side of the basin. The upper half of the ourse of the main stream is eroded out of the soft Tertiary strata, the ren under ofits course to a point below the mouth of North Fork closely « orms to the de- markation between the Mesozoic and Tertiary formatio: . the latter oceu- pying the whole of the basin area lying to the north of t. »river. At one point, in the neighborhood of Du Noir or Willow C °ek, the stream touches the Paleozoic mountain flank, where for a short istance it fiows in @ narrow gorge walled by Carboniferous sandstone. This narrow belt of Mesozoic and Paleozoic strata alon ' the southwest border of the basin has already been noticed in the acec nt of the geol- ogy of the eastern flank of the Wind River Range, to w. ch it properly pertains, geologically. The stratigraphicai relations oc the two sec- tions are uninterrupted and most intimate; erosion in ; ‘eglacial time having swept away the unconformable Tertiary deposii_, exposing to view the older formations over quite extensive areas ii the interval lying between the river and the mountain flank. Durii .° the glacial poch, when the mourtain gorges were filled to the brim with moving bodies of ice, vast quantities of erratic materials were tra1 ported from the interior of the mountains and spread out in orderly diso: ler over the bared sedimentary formations in the slopes along their fo t. ‘The lat- ter accumulations are conspicuously displayed in the embou hures of all the streams that rise in the interior of the range as far sou ‘h, at least, as Little Wind River. But, perhaps, their most extensive e hibition is found in the debouchures of Bull Lake and Campbell’s Fo: ks, and on Torrey’s Oreek, where the drift lies scattered over broad area and reach- ing perhaps a thousand feet up on the mountain side, their »ccurrence everywhere clearly displaying their origin. Besides the hug. morainal ridges flanking either side of the debouching mountain valle) s, the ad- jacent mountain slopes are corrugated with the peculiar sh rt ridges composed of loose materials which were borne to their presei t resting places by glacial agents. Concerning, therefore, the remaining geologic characteristics of the basin area, there only remains to be noticed the great Tertiary forma- tions that are known to outcrop over the greater portion of its surface, and such Quaternary and modern deposits as were observed the present season. In a previous report, as also in preceding pages of the present re- port, allusion has been made to the great voleanic-capped water shed in the vicinity of Togwotee Pass, and in the chapter devoted to th: Gros _ Ventre Basin, brief mention was made of the geologic components of that portion of the watershed lying between Togwotee and Union asses. The latter forms a low mountain barrier, separating Wind Riv: ° from Gros Ventre drainage, and, as previously stated, it is almost e.tirely made up of Tertiary formations. The ridge, however, retains the vol- canic capping to a point perhaps 10 miles south-southeast of Togwotee Pass, and remnants of the same sedimented volcanic ejectamenta were found crowning low eminences on the summit still farther south to within 6 miles of Union Pass trail. On one of thelatter points Station XX VIII was made, which has an altitude of 10,142 feet above the sea. Soon after leaving the summit of Togwotee Pass, the nascent stream begins to erode its bed into the soft deposits that underlie the great voleanic accumulations, and which appear in bluffs of gradually in- creasing height as low down as the confluence of the first considerable affluent from the north, just below which, or some 12 miles from its ulti- sT JOHN.] WATERSHED—UPPER WIND RIVER VALLEY. 257 mate source, the stream emerges into a meadow-intervale, at which point the valley proper may be said to begin. In this distance the stream has made a descent of about 1,800 feet. Towards its source the bluff-banks show limited exposures of brownish green arenaceous deposits, with indurated streaks of sand and pebbles, dipping at a slight angle northwards. At one point these deposits are seen to overlie a con- glomerate ledge composed of water-worn quartz pebbles held in a fine are- naceous paste, the whole being stained a green tint probably by iron infiltrations. This conglomerate is identical with similar occurrences along Black Rock Creek on the opposite side cf the watershed, rem nants of which were found on the summit of the watershed to within a few miles of Union Pass. In all, save its green color, it bears close physical resemblance to the great conglomerate elsewhere noticed as occurring in the Tertiary area of the Gros Ventre Buffalo Fork Basin. Its relation to the great volcanic deposits that make up a thousand feet and more of the heights on either side of the pass is not clearly mani- fest, nor are its relations to the beforementioned conglomerate of the Gros Ventre Basin any better displayed. Lower down the stream the greenish arenaceous deposits continue to appear, often forming blufis of an hundred feet and more in height, and apparently gently inclined in the direction of the stream. Ata locality 6 or 7 miles from the summit of the pass and about 1.100 feet lower, the abrupt terrace-face shows practically horizontal layers of greenish-gray, coarse and fine grained earthy sandstone with thin seams of dark car- bonaceous clay, the earthy layers yielding imperfectly-preserved leaves and stems of plants. Amongst these remains Professor Lesquereux doubitfully recognizes a Ficus, whose relations seem to be rather with forms prevalent in the Green River Tertiary group than with those occurring in the Laramie formation. The greenish arenaceous deposits are here associated with lighter-colored strata of similar composition, which latter increase in relative importance as we descend the stream. A mile or so below the above locality, the steep bluffs bordering the north side of the stream show a ledge of coarse conglomerate interbed- ded with thin, irregular layers of greenish-gray, soft sandstone, overlaid by yellowish sandstones. The conglomerate outcrops 40 feet above the water, and in lithological appearance it bears marked resemblance to the Tertiary conglomerate on the Gros Ventre and Buffalo Fork. Above the confluence of the first considerable north affluent, the bluffs on the main stream show 100 to 200 feet thickness of light-yellow soft sand- stone, and gritty clays with shaly gray sandstone above, the whole ap- rently in nearly horizontal position. The north side of the stream for several miles, both above and below the confluence of the north tributary, is bordered by a high bench or terrace, which is made up of the above-mentioned stratigraphic exhibitions. The slope on the opposite side is more gradual, and for the most part densely wooded. Ata point perhaps a couple of miles below the confluence, or 13 miles distant from the summit of Togwotee Pass, the terrace, which is here 500 feet above the stream, exhibits several ledges of soft butt- gray and greenish-tinted coarse-grained sandstone, in places shaly or thin-bedded, with pebble layers, and interbedded with soft arenaceous clays. No fossils were observed in these beds, which have aslight east- erly or northeast inclination. A little lower down the valley, which here opens out into a considerable meadow tract, the gentle lower slope of the bluffs reveals obscure exposures of pale-red clays, forming thin bands seldom more than a few inches in thickness included in greenish- drab clays. A mere glance, without reference to their associated strati- 17 258 REPORT UNITED STATES GEOLOGICAL SURVEY. graphic relations, might lead the observer to identify these horizons with the Triassic *‘ red- beds, ” the first authentic exposures of which, however, are only met with at a ‘point several miles lower down the valley in the neighborhood of Warm Spring Creek. From the summit of the terrace a broad, shallow depression, occupied by a small stream flowing eastward, and probably tributary to the milky affluent that joins Wind | River a few miles above Du Noir Creek, iS over- looked, beyond which rises a considerably higher outlying bench on the flank of the great volcanic mountains whose sedimented horizontal ledges tower hundreds of feet above in magnificent architectural mount- ain forms. The abrupt southern declivity of this outlying bench, as seen from a distance, appears to be composed of more or less indurated deposits, including a heavy bed of dull brick-red color, and above a rusty weathered ledge which is’ in turn overlaid by light ash-colored earth reaching up into the summit. The vertical extent of these depos- its, which are nearly horizontal, is estimated at 500 to 800 feet, while both from their position and lithologic characters they are doubtless identical with the greenish arenaceous beds met with along the upper course of Wind River. Their relations to the volcanic mountain bor- ders both to the north and southwest, and the inferior creamy-yellow sandstones is shown in an accompanying profile section of the valley along a line extending northeast from Station LI (1877) on the water- shed on the south side of the valley. . North of the point where the small parallel tributary leaves the first. terrace bench and enters the undulating, grassy region lying just to the east, a considerable thickness of banded bluish-drab and red deposits appears in low bluffs along the broken eastern edge of the terrace. The above exposures occupy a sort of recess in the lower terrace level, to the west and north of which the acclivities rise up into the higher bench, which here shows obscure, pinkish-drab, red-streaked exposures. The probable stratigraphical relations of the banded variegated beds here alluded to will be referred to further on. To the northeast, brownish earthy deposits appear in a somewhat higher bench, and in the lower slopes, descending from the volcanic mountain ridge, quite extensive tracts are oceupied by light drab, clayey deposits in the region of the, upper course of Du hoir “Creek. The above mentioned terrace is continued along the north sade of Wind River, east, to within perhaps 3 or 4 miles of the mouth of Du Noir Creek, where it assumes the character of a high morainal bench, jutting into the valley. It is, however, somewhat lower, interrupted by short drainage depressions, and at a "point perhaps 4 ‘or 5 miles above Du Noir Creek it is cut by a smaller affluent whose waters are charge with milky-colored sediment. The latter phenomenon is doubtless at- tributable to the wash of white earthy deposits which were observed to occupy a considerable area some miles to the north, or northwest, in the region of the sources of this stream. But as we descend the valley, the blutis gradually increase in elevation, frequent exposures of the component strata appearing in the more or less steep slopes fae- ing the valley. Ata point some distance above the confluence of the sediment- discolored stream, where the bluffs approach the river, a thin seam of lignite outcrops a few feet above the water. level, associated with chocolate-red and bluish-drab clays, overlaid by rusty yellow and grayish shaly sandstones in bluff-face, 150 feet above the stream. The sandstones were observed all along the bluff face before reaching this locality, appearing in nearly horizontal ledges separated by soil-covered slopes, though in places apparently gently rising to the eastward as the Plate XLVII. Sta. LI. Sta L. Wind River. — Togwotee Pass. IPANTTEETTED Rhea — ao aodote. Profile of Upper Wind River Valley and Togwotee Watershed (looking NW.). a Flowed lavas, &c. b Sedimented volcanic ejectamenta. c Green, dull-red, and ash-colored deposits. d Sandstone, clay, lignite—Tertiary (?). heir ne es anes Hy st. JOHN.] LARAMIE (?) AND TERTIARY—UPPER WIND RIVER. 259 stream deepens its bed. Between the latter stream and Du Noir Creek, the north side blufis exhibit the same series of strata, consisting of rusty-buff sandstones, drab and yellow sandy clays with streaks of red clay, of which a thickness of 250 feet are here exposed. These deposits are overlaid by variegated or banded pale-red and drab clays, showing a thickness of 50 feet or more in the top of the bluffs, the whole sloping off to the northeastward at a very gentle angle of inclination. It was impossible at this locality to determine whether the superposi- tion of the latter deposits is conformable to the inferior lignite-bearing formation, nor was opportunity afterward afforded for the satisfactory settlement of the question. I have also to regret the uncertainty as to the stratigraphic relations of the above geological formations with the previously noticed greenish arenaceous deposits occurring towards the head of Wind River. Indeed, lithologic data, which are quite persistent and reliable in the Gros Vetitre region just over the watershed to the west, seem to be confused and less trustworthy guides to the identifica- tion of portions of the Cenozoic series as we approach that part of the divide which is surmounted by the great volcanic deposits. The com- paratively undisturbed condition of all the geological products, includ- ing even the sedimented volcanics, occurring in the region about the . sources of Wind River, renders the detection of nonconformities an ex- tremely delicate operation; and when we take into consideration the action of thermic agents accompanying the great volcanic accumulations that were spread out over so vast an extent of the Cenozoic area in this region, we may well hesitate, in interpreting meager data, to assign the appearances here met with to changes akin to those induced by meta- morphic agents, or to those other potent agents of geologic change, ero- sion, and deposition of distinct and unconformable materials. The con- glomerates noticed on Wind River certainly bear close analogy to the great conglomerate horizon underlying the upper or Teritary lignite- bearing series on the Gros Ventre, 15 miles to the westward. Yet, with the paucity of facts at present in hands, bearing on the detail strati- graphy of the Wind River section, it might be deemed presumptuous to assert the identity of the above occurrences. But when we come to the correlating of the supralignite series represented by the pale-red and drab variegated or banded deposits, the occurrences in the above-men- tioned regions are so alike as regards both their stratigraphic constitu- tion and geological position, that little or no doubt can be entertained respecting the actual identity of the latter deposits in the regions of the Gros Veutre and Wind River basins. The few fossils found in the lig- nite series of the Gros Ventre Basin here referred to were provisionally compared by Dr. White with Bear River Laramie forms; while the immediately superimposed conformable strata afford a Viviparus palu- dineeformis (2) which elsewhere characterizes Wasatch Tertiary hori- zons. Hence, the variegated deposits to which Dr. Hayden gave the name Wind River Group, recognizing their probable Miocene age, are either emphasized variegated upper Wasatch strata or a much later and actually nonconformable member of the Tertiary series peculiar to the region north of the Gros Ventre Mountains, and east of the Wind Ktiver Range, in which quarter as yet no Green River Tertiary equiva- lents have positively been recognized, unless the plant-bearing beds above noticed prove to be of that age. The attempts hitherto made to correlate the Wind River Group have been based on supposed lithologi- cal resemblances, I believe, without the aid of paleontological evidence. Du Noir Creek occupies a fine valley eroded out of Tertiary deposits, in the east side of which variegated red and drab exposures are seen. 260 = REPORT UNITED STATES GEOLOGICAL SURVEY. In the uplands to the east the same variegated series occurs over a wide belt extending down the middle of the basin, and is overlaid by ob- scurely exposed deposits of drab clays and soft yellow sandstones. Just below the Du Noir, the north side terrace closely approaches the stream which has cut a narrow gorge in the tiited Carboniferous sandstones reclining on the flank of the Wind River Mountains, as described in a preceding page. The relations of the basin Tertiary deposits to the Paleeozie series in the mountain-flank at this locality are concealed by drift accumulations mantling the terrace. But in the north side of the expansion into which the valley opens below the narrows, the variegated deposits are exposed on an extensive scaie in the deep recess which here penetrates the upland; the soft materials of which they are composed readily yielding to the elements, which have wrought with wonderfully intricate picturesque effects in the sculpture of the barren bluffs that inclose this side of the valley. A few miles below the narrows, the uplands again approach the stream which here traverses a narrow passage cut into the dark red sandstones * of the Trias, which latter form the basis of the outlying terrace along the foot of the Wind River Mountains. A limited exposure of Jurassic strata occurs in the bench on the north side of the stream, upon which rest the nonconformable variegated Tertiary beds. The latter here rise up into a prominent headland, 600 feet or more in height, which was utilized for topographic purposes the previous season (Station LI, Té- ton division). These deposits here consist of alternating bands of pale- red and greenish-drab clays, with irregular or local thin layers of gray and y ellow sandstone. ‘The eminence is covered with a thickness of 10 to 30 feet of brown earth and drift materials resting upon the planed- off surface of the variegated beds. The latter here incline to the north- eastward at an angle not exceeding 5°; the underlyins Jurassic beds dip in the same direction at an angle of 15° to 20°, the nonconforinity being marked as seen in the natural exposures ata distance. Itis prob- able a thickness of at least 1,000 feet of these deposits is seen in the picturesquely eroded area of their occurrence here alluded to, while their total vertical extent may be found to exceed this estimate. The com- paratively limited unexposed space intervening between the Jura and variegated Tertiary at this locality is wholly insufficient to admit the heavy series of yellow sandstones and clays of the lignitic series which higher up the valley were found underlyi ing the variegated deposits. Hence, it is reasonably inferred that the lignitic formation was here denuded prior to the deposition of the variegated beds, which at this locality rest immediately upon the unconformable and also extensively denuded Juarissic strata. Some notion of the distribution of the various geologic formations of the region may be gained from the eminence on which Station LIT (1877) was located. The banded Tertiary deposits have extensive areal dis- tribution to the north and east. The great sedimented volcanic ridge, constituting the Sierra Shoshone of Captain Jones, is traced from Tog- wotee Pass, eastward, along the northern rim of the basin, terminating in a group of lofty pinnacles lying to the east of the sources of North Fork Wind River, and which are probably the Washakee Needles. Irom the latter mountain ridge, the Owl Creek Mountains are separated by a gap, and at their base lies a massive outlying bench in which an enor- mous thickness of similar variegated deposits is visible. The valleys of Horse Creek and North Fork are excavated in these deposits—their fringes of cottonwood and green shrubs presenting a pleasing contrast to the environing red-striped barren hillsides, in appearance a semi- badland region, destitute of more than scant pasturage. Plate XLVIII. Wind River Mts. Warm Spring Caiion. Togwotce Pass. Sierra Shoshone. = = ET wsyw W (maz.J wivw Wind River Valley, below Warm Spring Creek. @ Silurian. b Carboniferous. e Jura-Trias. d Wind River Tertiary. e Voleanic tuff, breccia, conglomerate. Jf Spring deposits—cale. tufa, gravel concrete. Aieee j fs st. JOHN.| NONCONFORMITY OF WIND RIVER TERTIARY AND JURA. 261 Below Horse Creek the variegated Tertiary skirts the stream, forming _ beautifully eroded blutis 300 feet or more in height, the lower portion showing some discordance in deposition, but not in constituents and gen- eral appearance. The coloring matter appears not to have been distrib- uted with perfect regularity, the belts of red becoming locally intensified by the merging of several narrow bands in one, and associated with fre- quent indurated arenaceous bands, which give rise to a great variety of monumental forms in the weather-sculptured bluff-face. These deposits continue thence along the north side of Wind River to near the eastern boundary of the district. In the vicinity of the confluence of North Fork they are again crowded back some distance from the stream and rest unconformably on the Jura, which at this place crosses to the north side of the river, forming a rather high sboulder outlying the Tertiary uplands east of North Fork. Above Campbell’s Fork, on the north side of the river, there occurs a heavy series of dirty-yellow and drab clays or arenaceous deposits, the stratigraphical relations of which, for lack of time, could not be satis- factorily determined, although they apparently underlie the banded Ter- tiary. The latter again reaches the stream opposite the confluence of Campbell’s Fork, where it forms bluffs 200 to 300 feet high. It is made up of alternating pale-red and bluish-drab layers, often of considerable thickness, the disintegration of which produces a drab soil covering the talus slopes for more than half the height of the blutis. A couple of _ mniles or so below Campbeli’s Fork the variegated deposits appear in the terrace on the south side of the river, the red and drab bands alternating with yellow sandstones. The terrace bordering the opposite side of the valley exhibits frequent though rather obscure exposures of the same deposits, showing a preponderance of sandstone layers as we advance, and which are gently inclined in the direction of the descent of the val- ley, though locally varying in the direction and amount of inclination. A few miles below the confluence of Crow Creek an isolated hill rises nearly a thousand feet above the level of the valley, forming a promi- nent landmark, which is known as Crow-Heart Butte. This eminence, which was detached by erosion from a high terrace level lying a few miles to the north, is based upon obscurely exposed variegated deposits, overlaid by a heavy deposit of rusty-yellow sandstones and drab clays forming the middle portion of the butte, upon which rests a somewhat less thickness of similar clays with reddish layers, the summit capped with a heavy ledge of rusty-yellow sandstone. The summit sandstone belongs to a heavy ledge that recurs in the above-mentioned high ter- race, while the middle sandstone horizon is the same that constitutes the main terrace bordering the valley. The inferior basis deposits re- semble the variegated horizon noticed higher up the valley, as men- tioned above. Wherever this region was overlooked from the mountain border on the southwest the above-mentioned deposits always had the appearance of gently rising to the northwest in ascending the valley. Yet these appearances should be taken with due allowance when it comes to determining the geologic relations of the horizons here alluded to. Below Crow-Heart Butte, as far as the stream was followed, the bor- der blufis on either side revealed frequent exposures of greenish-yellow soft sandstones and arenaceous shales with layers of blue clay. The concentrated clayey portions of the rock are often weathered away, form- ing shallow caverns in the mural exposures. In the vicinity of Dry Creek, a few miles below Bull Lake Fork, rusty buff-weathered sand- stones appear in the bluffs on the north side of the valley, where they are gently upraised to the southwest and overlaid by a considerable 262 REPORT UNITED STATES GEOLOGICAL SURVEY. d thickness of variegated chocolate-red and drab deposits. Butin the up- lands on the opposite side of the valley, over which the road to Camp Brown leads, the horizontal Tertiary sandstones are again met with. Mention has already been made of some fossiliferous sandstone oceur- rences, of probable Tertiary age, in the debouchure of Jake’s Creek. These exposures are practically horizontal and fill a depression eroded out of the tilted Jura-Trias at the foot of the Wind River Mountains. Below this the Tertiary area is crowded to the north side of Wind River and is not again met with on the south side of the stream until reaching Campbells Fork, nine or ten miles to the east-southeast. At the latter locality a series of nearly horizontal drab and dirty-yellow soft sand- stones appears in the blufis bordering the stream for a mile or more, and which extend up the valley to a place nearly opposite the head of the lake, where they abut against the upraised Triassic “red beds” in the mountain flank. The same deposits occur in the bluff borders along all the deeper drainage channels that flow down from the Wind River Mountains between Campbell’s and Bull Lake Forks, where they hold the same unconformable relations to the outlying Mesozoic belt at the foot of the mountains. But in the interval between North Fork and Campbell’s Fork, where the outlying Mesozoics are projected beyond the mountain-foot in a sort of broad, low arch, across the outer edge of which the main stream has eroded its channel for several miles, the va- riegated red and drab deposits rest immediately upon the unconforma- ble older formations without intervention of the above-described Tertiary _ sandstones. It may be urged that the latter sandstones hold a strati- graphie position superior to the variegated deposits, in which case it is evident that the heavy lignite-bearing series of supposed Wasatch Ter- tiary occurring in the Gros Ventre Basin just over the watershed at the head of Wind River, if not wanting, is so attenuated as to escape recog- nition in the denuded borders of the lower Wind River Basin. | Bull Lake Pork, immediately it leaves the mountains, exhibits an un- usally clear section of the Tertiary sandstones. They here occur very much in the same manner as on Campbell’s Fork, impinging at a sharp angle against the inclined Cretaceous strata occurring in the outlying bench at the foot of the mountains. The highest exhibitions of these strata occur in the bluffs about opposite the head of Bull Lake and between 600 and 700 feet above the water-level, the beds showing slight easterly inclination in the direction of the basin. Perhaps a mile lower down, on the north side of the lake, a section showing a vertical thickness of about 400 feet in this horizon was examined. Section of Tertiary strata on Bull Lake. » No. 1. Unexposed slope to level of Bull Lake, 145 feet. No. 2. Coarse, dirty-yellow sandstone, containing pebbles of metamor- phic rocks and pockets of green clay, exposed 25 feet +. No. 3. Soft, almost incoherent dirty-yellow sandstone, with thin layers of green clay and small coneretions; fragments of fossil-wood in upper part, 259 feet +. No. 4. Buff, coarse-grained, soft sandstone, with greenish arenaceous clays below, heavy-bedded above, and containing regular and irregular. shaped sand and ferruginous sand concretions, 125 feet exposed. No. 5. Brownish-yellow clay or soil, 20 feet +L. No. 6. Slope occupied by irregular parallel ridges of morainal mate- rials reaching up into summit 700 feet above level of Bull Lake. The Tertiary beds are planed off even with the tilted edges of the \ st. sonn.] WIND RIVER BASIN—TERTIARY AND POST-TERTIARY. 263 Mesozoic series, forming a gently sloping plane loaded with morainal deposits. The south-side blufis exhibit less perfect exposures of the same rocks, which extend but a short distance below the lake, whence the border slopes and uplands alike are covered with the loose drift materials all the way to Wind River. A high bench projects into the basin between Bull Lake Fork and Sage Creek, traversed by two or more narrow drainage channels, in the steep bluffs of which similar exhibitions of horizontal Tertiary strata are met with. In the borders of one of these ravine-like depressions about two miles south of Bull Lake Tork and as far again from Wind River, the exposures consist of soft yellowish sandstones containing vegetable remains like compressed stems, and which are weathered into curious monumental forms by atmospheric erosion. Higher beds apparently be- longing to the same series were observed in the divide between Wind River and Sage Creek, in the south slope of which to the west of the depression down which the road passes into the valley of the latter stream, the same soft yellow sandstones reappear, in horizontal position, on the west flank of the outer mountain fold in which the Mesozoics are brought to view. A few miles to the west-northwest of the last locality, in the high out- lying bench, pale red variegated deposits overlaid by drab and greenish arenaceous clay appear in the east side of a wide shallow drainage de- pression tributary to Sage Creek above the bend. These deposits, con- stituting here well-marked horizons gently inclined in the direction of Wind River, hold a position superior to the dark drab clays of the Creta- ceous Colorado Group, and to the northeast they pass beneath the above- mentioned soft yellow sandstones that occupy the interval extending over to Wind River. The geological relations of these horizons are obscured along the line of contact with the subjacent Colorado shales, where they have been eroded and overlaid by the uncontormable conglomerate of Pliocene, or possibly Post-Tertiary age. This interval may well embrace the horizon of the Fox Hills Cretaceous, which shows characteristic ex- posures in the bluffs above Bull Lake. Lithologically, the deposits here alluded to recall the exposures on Wind River in the vicinity of Dry Creek, where. as has been stated in a preceding page, similar reddish and drab horizons occur, resting upon a heavy ledge of buff sandstone, which is gently upraised to the southwest. The local appearance of the above-mentioned deposits is shown in the profile section representing the mountain flank in the vicinity of Sage Creek Caton. At the time of the examinations in this quarter it was the impression that the reddish varie- gated beds here alluded to were one and the same with the great forma- tion of similarly colored variegated deposits that constitute so important a geologic feature in the mid-basin area a little higher up Wind Miver. Post-Tertiary.—In the area of the basin region, even including the mountain border, it is probable that comparatively slight changes in the pre-glacial surface contours have been effected by the erosive agents that have wrought during and since the glacial epoch. Speaking in gen- eral terms, the conntry here alluded to has probably suffered to greater extent changes in its surface configuration due to fluviatile and those other potentatmospherical denuding agents than that produced by glacial action. The latter has evidently acted with greater effect as a degrad- ing force in the high mountain regions, while in the lower border region it was chiefly confined to a transporting function. In this latter respect the results are grouped about the debouching cafions, where they may be advantageously studied as so many local exhibitions of a part of the phenomena of glacial section. The great ice-flows naturally sought the 264 REPORT UNITED STATES GEOLOGICAL SURVEY. depressions already existing, down which they slowly moved bearing and pushing along their burden of detrital materials, which were un- loaded and built into the huge morainal ridges filling lateral depressions along the mountain course of the glacier and piled up on the surface in the edge cf the plain. These occurrences furnish the most legible evi- dence of the magnitude of the individual glaciers descending along the eastern flank of the Wind River Range, which in some instances ex- tended beyond the mountain foot 2 distance of several miles out into the basin. E While denuding agencies of one kind or other have wrought with startling cfects, carving out stupendous mountain forms and broad valley depressions, the phenomena resulting from these actions, as seen to-day in the region of the sources of Wind liver, present comparatively small evidence of glacial origin. This may be attributable to the soft nature of the geological formations in that region, but the glacial de- posits which were here found are much less conspicuous than these met with along the foot of the Wind River Mountains. However, the oceur- vences along the upper course of Wind River present the same evidence of the local extent of the glaciers as those met in the mountain borders to the south. The erratic materials along the stream as far down as Warm-Spring Creek may be traced to the conglomerate and great vol- canic conglomerate and lava formations, that encircle the head of the valley. The materials consist almost exclusively of the various sorts of voleanic rocks, basalt and trachytic lavas, found tn sitw in the meuntain summit about Togwotee Pass. They have been distributed by trans- porting agents as far down the valley as North Tork, at least, though below the confluence of Warm-Spring Creek they are mingled with other kinds of rock débris derived from the Wind River Mountains, becoming less and less conspicuous and finally disappearing as a com- ponent of the superficial detrital deposits along the stream. Above Du Noir Creek, the upland benches a few miles north of Wind River are sparsely covered with water-worn erratics consisting chiefly of voleanic rocks, and sparingly of fragments of reddish-white lami- nated quartzite and dark drab limestone resembling ledges occurring in Carboniferous and Jurassic horizons, and which evidently were brought down from the mountains lying to the north. But for the most part these upland slopes are covered with light sandy soil derived from the disintegration of the subjacent soft arenaceous Tertiary deposits. Above Du Noir Creek the uplands are more thickly strewn with water-worn volcanic bowlders which embrace all the varieties of these rocks occur- ring in the watershed around Togwotee Pass, the deposit having much the appearance of morainic origin. The wide intervale at the conflu- ence of Du Noir and Wind River is paved with these erraties. Just below in the neighborhood of Warm-Spring Creek, glacial phe- nomena, So far as they are dependent on morainal deposits for their recog- nition, are perhaps not of the most conclusive character. The mountain side at an elevation of 600 feet above the valley is strewn with unevenly dispersed accumulations of probable glacial origin. ‘The loose materials consist of a variety of metamorphic rocks such as occur in the interior portion of the range, together with limestone fragments from the outer flank of the mountain. But lower on the slopes or in the benches bor- dering the basin, these abraded erratics are spread out in well-defined terraces where they have been transformed into a sort of conglomerate by calcareous infiltrations from springs, with which are associated a variety of interesting phenomena. It is difficult to decide the relations of the bowlder deposits in the st. JOHN.| MORAINAL DEPOSITS EAST FOOT WIND RIVER RANGE. 265 terraces vicinity of Warm-Spring Creek to the undoubted glacial de- posits. They appear in terraces along the south side of the river, at elevations of 150 feet or more. The deposit is composed of well-rounded fragments of volcanic rocks, limestone, quartzite, and occasional granitic pebbles, obscurely bedded, with thin sheets of sand. ‘The impression derived in the course of hastily made examinations was that these de- posits antedate the glacial epoch, in which event they might properly be relegated to the Pliocene. Their consolidation might have taken place at a much later date from caleareous matter deposited by perco- lating spring-water. in the vicinity of Jake’s and Torrey’s Creeks, the morainal deposits are on a scale of great magnitude, presenting all the characteristic phe- nomena usually associated with glacial accumulations. The outlying terraces are strewn over a wide area with this vast accumulation of erratic materials, reaching from the river back to the mountain where they occur at an elevation of several hundred feet above the valley. In the constitution of the deposit metamorphic bowlders largely predomi- nate, with which are sparingly associated fragments of limestone and quartzitic sandstone belonging to readily recognizable formations plating the neighboring mountain flank. The region occupied by these deposits forms a sort of high bench either side of the debouchures of the streams, the surface roughly furrowed just as the material was discharged from the glacier. Remnants of the glacial deposits occur on the north side of Wind River below the mouth of Torrey’s Creek, where they are seen clinging to the steep bluff slopes over the variegated Tertiary formation. Yo the southeast the mountain slope is again unmasked until reaching Campbells Fork, where similar morainal deposits are met with, though on a less extensive scale. At the latter locality the erratic materials are piled up in well-defined lateral morains on either side of the stream as it leaves the mountain, and which extend all the way to Wind River a distance of nearly 4 niles, where they are spread out in irregular low benches. The moraines rise up on the foot of the mountain attaining an elevation of near 8,400 feet, or 1,000 feet above Wind River. In the gorge across the sedimentary ridge the Carboniferous limestones at one point form a natural bridge, and everywhere in the barred surfaces the rock still retains in legible characters the record engraved by the glacier in the smoothed and polished ledges. This is the more remarkable con- sidering the exposure to which these rock surfaces have been subjected. The cation has been swept clean of these materials, but within the rugged mountain basin they recur under a variety of local aspects. The streams to the south that rise in the more elevated portion of the range all exhibit in their debouchures interesting evidence of former glacial occupancy. But none of the smaller streams show morainal de- posits of near the magnitude of those above noticed. This is evidently due to the fact that the present streams do not penetrate so deeply into the more elevated regions, and hence the glaciers that once descended along their valleys were smaller and derived their products from less abundant sources. The lateral moraines on Dry Creek below the de- bouchure are quite as perfect examples of their kind as any to be met with on this side of the range. They reach well out into the sloping plain, presenting in their surface contour the several bench levels in the steep valley declivities marking the stages in diminution in the volume of the glacier and on the opposite side the furrowed gentler slopes de- scending to the general upland level. Between these streams the mountain side reveals the sedimentary formations in great upraised benches which form a characteristic feature in the surface configuration of the flank of the range. 266 REPORT UNITED STATES GEOLOGICAL SURVEY. The Bull Lake Fork moraines are precisely like those above described, being heaped up on the planed-off surfaces of the Mesozoic and Tertiary deposits and reaching well up on the foot of the mountain to an eleva- tion of 1,200 feet or more above the stream. They reach out into the basin as far as Wind River, or a distance of nearly 10 miles, the deposits apparently inereasing in magnitude in that direction, where they soon conceal from view the subjacent geological deposits. The lake was formed by a low barrier which marks the site of a terminal moraine, similar occurrences being met with lower down the stream giving rise to a chain of water-expansions or lakelets. One of these low terminal moraines crosses the valley haif a mile or so above the lake, which the stream has broken through, forming a narrow passage where it shows a height above the water of about 30 feet and a breadth of 75 yards. Looking up into the mountain basin the Archean ledges present ex- tensive “glaciated surfaces and huge ridges of morainic origin. Allusion has already been made to the glacial phenomena prevalent on Little Wind River. The two inain branches of this stream cross the outer mountain ridge by independent canons, uniting in the plains be- low. Their exits from the mountains are accompanied by morainal ridges constituting prominent features in the magnificent view of the mountains as seen from the valley in the vicinity of Camp Brown. The barred sedimentaries appear on the mountain side in the interval be- tween the two streams. In the bed of the valley of the North Fork, just: below where it leaves the mountains, low parallel ridges of morainic origin are met with which may be remnants of medial moraines merged with terminal deposits. In the high blufis on the north side the lateral moraine rests upon a heavy bed of Pliocene (2) conglomerate which inter- poses a hundred feet between the glacial deposits and the tilted Mesozoic strata. The north-side lateral moraine attains an elevation of about 1,500 feet above the stream, rising up on a high shoulder which breaks down in a precipice several hundred feet in height on the canon side. Within the broad and rugged mountain basin moraines of even greater magnitude were built up along the principal tributaries. The latter in places traverse beautiful tracts of grassy, forest-environed intervales, the region indeed abounding in scenic contrasts the most beautiful and sublime. Tufaceous deposits, &c.—Along the northeastern foot of the Wind River Mountains some interesting occurrences attributable chiefly to deposi- tions from springs issuing in the immediate border of the basin were met with, of which a brief account is embodied in the following pages. The first of these deposits occurs in the immediate neighborhood of Warm Spring Creek, where their origin is perhaps most clearly revealed. They extend to the southeast as far, at least, as Campbells Fork, and certain conglomeritic deposits with which they are here associated have similar, if not identical, recurrences still farther south to the neighbor- hood of Little Wind River. In the south side of Wind River, at Warm Spring Creek confluence and a few miles below, recent deposits of calcareous matter have been made by springs which have not yet altogether ceased flowing. Their deposit forms a light, porous rock retaining impressions of leaves and land snails of living forms, and cf comparatively limited extent in the low terrace bordering the intervale, 15 to 35 feet above the stream. As- cending Warm Spring Creek it is presently shut in by the bluffs of higher terraces that rise in two distinct levels. In the edge of the higher bench, perhaps half a mile above the mouth, the creek has eut through a mass of tufaceous limestone, where, on the east side, at an « antl 4 Ie Se mt , we: Mt! hg 5147.72 hi” ia At ’ Ke My ee tf 9 \ 4 ‘ty r 5 i ¢ / a a sce8h bl Se f fy a) : « Le | 7 Plate XLIX. Profile of spring deposits on Warm Spring Creek. Fig. la. Outline of ovifice of ancient spring, 15 by 50 feet. Fig. 1b. Section of ancient spring, partially filled with water. Nyp22%r Pre = yv? ar os tinct Spru Lastt above iv. sT. JOHN.| TUFACEOUS SPRING DEPOSITS WARM SPRING CREEK. 267 elevation of, perhaps, 150 feet above the river, it is surmounted by a broad, low cone or mound, in the centre of which oceurs the irregular orifice of the spring. The spring has long since ceased to overflow, and, if it is not extinct, its waters seek subterranean outlet. The orifice has a diameter of about 15 by 50 feet and a depth of 25 to 30 feet, with a cavernous chamber extending under the southwest end which was par- tially filled with still water. The outline and section of this ancient spring is shown on accompanying plate. In an irregular bench, about 250 feet above the last, a still heavier accumulation “of tufaceous lime- stone occurs, which for ms the highest deposit observed at this locality. The mass forms sloping benches in the mountain declivity, made up of thin lamine and layers, 4 to 6 inches thick, of a more compact, dense structure than that of the more modern deposits now in process ‘of tor- mation. Looking up the Warm Spring Cafion an interesting and picturesque natural bridge spans the stream, which, although it was not visited, has every appearance of the tufaceous rock above noticed. Its origin at this locality, wedged in between the precipitous limestone watis, is in- volved in some obscurity; at all events the mass has the appearance of once having choked the bed of the cafion, the stream subsequently cut- ting a channel beneath without undermining the deposit. A short dis- tance below the above-mentioned spring orifice, in the east-side angle of terrace bluff, another extinct spring mound occurs. The formation, in the present instance, is nearly circular in outline and about 45 feet in diameter. It forms a low, broad-topped mound rising 8 to 10 feet above the level of the terrace, its centre slightly concave, where the orifice is completely choked by the dishing depositions that were precipitated in the last stages of the spring’s activity when it had ceased to overflow the rim of its shallow basin. A partly ideal section of the spring mound is given in an accompanying plate. About a mile below Warm Spring Creek and half a mile back from the river quite extensive deposits of calcareous tufa fill the mouth of a ravine in the edge of the terrace, where they form a series of broad steps or successive bench-overflows, of which there are three well-marked ones. They are being built up by active springs whose temperature was about 84° F. On the east side of the ravine a rather prominent extinct spring crater rises from the slope, its summit about 200 feet above the wide bench descending to the river. ‘The crater, which is surrounded by irregular, vertical walls, is about 15 feet in its longest diameter by 10 feet in the shorter, and a depth of 20 feet, the bottom filled with débris. The thin layers of porous tufa limestone, of which the mound is composed, incline gently from the centre, on ail sides, and are sparingly intermingled with water-worn pebbles like those found in the drift of the terrace benches. The deposit is probably based on the sloping terrace, but its contact with the loose, superficial deposits is con-. cealed by the gravelly soil surrounding the base of the mound. A mile or two below the last locality mentioned above, extensive de- posits of tufa limestone occur in the slopes at an elevation 250 feet or more above the stream. Its outcrop, facing the valley, forms low blufis, in which the regularly bedded and nearly horizontal strata show a thick- ness of 50 feet. Seen at a distance the exposures are very deceptive, aid without previous knowledge of these occurrences their origin might readily be mistaken. The deposit consists of grayish-buff, more or less compact and porous, even-bedded calcareous tufa, very gently inclined to the west, in one place apparently conforming to the declivity of the terrace bench upon which it rests. In texture the rock is firmer and 268 REPORT UNITED STATES GEOLOGICAL SURVEY. more dense than the modern formations, though, so far as the evidence goes, it is difficult to assign these more ancient deposits a definite relative date as compared with the giacial drift. in a preceding page has been mentioned the occurrence of the par- © tially-cemented gravels in the first high bench bordering Wind River on the south for several miles below the narrows above Warm Spring Creek. These ancient gravel beds appear to have been intimately associated with the spring deposits, and if, as is inferred, these old bench deposits antedate the glacial drift, it removes a part of the tufaceous limestone formations to a remote period as compared with the similar deposits whose accumulation by accessions of living springs has not ceased. Of the latter deposits frequent occurrences were met with in ravines trav- ersing the benches opposite Horse Creek confluence, and in the border- ing blufis, resting upon the Triassic “ red beds,” the terrace conglomerate reappears. It is here made up of limestone, sandstone, and metamorphic pebbles, usually firmly cemented by calcareous matter, forming an exten- sive deposit rising up to the foot of the mountain and spread out over ancient terrace levels. In comparatively recent times the bench slopes have been subjected to erosion, which has, in some instances, at this lo- cality, isolated the conglomerate sheet in the midst of the barred “red. - bed” surfaces. Below this the morainal deposits, distributed by the Jake’s Creek glacier, are encountered, and which are piled up on the earlier terraces in irregular ridges, completely masking the subjacent deposits. In the mouth of Jake’s Creek Cation, Mr. Perry visited some interest- ing and extensive spring deposits which are still in process of formation. The springs have built up cones rising in the midst of platforms that were formed in the earlier stages of their flow. The water had a tem- perature of 68° F., that of the atmosphere 44° (2d October). Between Torrey’s Creek and Campbell’s Fork perhaps even more ex- _ tensive exhibitions of conglomerate and tufaceous limestone deposits are met with, the prevalent conditions being the same as noted in the region opposite HorseCreek. The Red Cafion occurrences may be taken as typical of the others found in the latter quarter. Here, upon old terraces moulded in the “red beds,” heavy deposits of conglomerate and tufacecus limestones occur, interbedded. These deposits were noticed in detail in the section of the rocks occurring in the mountain flank at this locality, given in a preceding page and accompanying plate of illus-- trations. The deposits measured about 60 feet, the members locally’ varying in thickness. It consists of, below, (16 a) variegated clays, 5 feet +, resting upon the uneven surface of the Triassic “red beds,” and forming the floor upon which the succeeding beds were deposited ; (16 b) conglomeratic bed, 10 to 15 feet, composed of pebbles of various kinds of rock occurring in the adjacent mountain, alternating with coarse sandy red clays, more or less local; (16¢) tufaceous limestone, varying from rather compact to porous laminated or thin-bedded rock, with calcite concretions, interbedded with layers of pebbles above and below, attaining a thickness of 50 to 55 feet, locally. The deposit. is quite variable throughout, in places the conglomeritic character prevail- ing. The pebbles consist chiefly of water-worn limestone fragments, with fewer sandstone and metamorphic pebbles. The deposit conforms to the surface contour of pre-existing sloping benches upon which it was laid down in an uninterrupted sheet. ‘this character is clearly shown in the natural sections along the streams and over the denuded Triassic area lying between the mountains and Wind River, where tufaceous and conglomeritic beds are seen at two or more levels rising up on the foot st. JoHN. TUFACEOUS SPRING DEPOSITS WARM SPRING CREEK. 269 of the mountains. Its outcrop forms a mural coping in the bluffs hem- ming the drainage depressions and in the summits of the isolated mesas with which this region is diversified. The highest benches in this re- gion may reach an elevation 1,000 to 1,200 feet above Wind River; the aneroid indicating nearly the same actual altitude for the deposits at this locality and in the vicinity of Warm Spring Creek, 16 miles above. South of Campbell’s Fork, 6 miles, a deposit evidently of the same origin appears in the low plutts bordering a little stream that here crosses the foreland slope, and resting nearly horizontally upon upraised Car- poniferous and Triassic horizons. It isa coarse or partially consolidated eray limestone, in rather even thin layers, with small siliceous pebbles. No fossils were detected, and the rock resembles some of the limestone layers of the Pliocene “lake-beds” of lower Bear River V alley, Utah. It was not detected on Bull Lake Fork, but just to the south of the latter stream, in the outlying bench slopes belonging to the Sage Creek drainage, apparently quite an extensive conglomeritic deposit was met with, which is probably synchronous with the above-mentioned occur- rences. The conglomerate is chiefly composed of water-worn limestone fragments and sandstone, more or less firmly cemented with calcareous matter. The bed reaches a thickness of at least 50 feet, and rests upon various members of the Mesozoic series occurring in the belt along the toot of the mountains. The same formation recurs in the bluffs north side of North Fork Little Wind River, where it rests upon the Triassic “red beds,” at an elevation of 800 feet above the stream. Metamorphic pebbles and small bowlders enter largely into the components of the deposit at this locality, interbedded with thin local sheets of soft buit sandstone, the whole loosely cemented and obscurely stratified. Con- elusive evidence of the preglacial origin of the deposit is not wanting at the present locality; the ridge above being loaded with the morainal materials brought down by the Little Wind River glacier. There can be no question as to the identity of the latter occurences with those briefly described in foregoing pages; the only contrast they present is the absence of the tufaceous limestone which at other localities forms an important member of the formation. ‘¢ e! < u a 30) —— J vow te NI FORT HALLYS 5 4783, a = = cy 3) OSS} /FORK : AG INCYY, 5 orl, 43° AAG | Malide SPP, SAMARIA, 3 | 4800 i) = S PORTAGE > A201 a 3 42 ties ee oaks Ty Go Je = K e hae < \\e * Spring cn\ ean Cn, ) fz A Leet Sima berry O° | ete PGs Saye snoshoP are” | } | LL "hoes Loy, yokes U wr ) Glacier 2&2 i , on \ VIRGINIA PK.‘ 3 3 5 RO OB: = ae eg ~_ HOBACK PK, z \ Ao ° ° ©10899 Lg caer oe ea = WYOMING PK, 1490.4 0 __/MT DARBY a MT LEIDY + MU LABARGE M? a 6622 Ce) So a / / v((, + - 8 ae 3 Ze } A 46300 57 : ——+— ping’, || Nia }} Joa | / } A | iD is Yer Robui Rectan gle 45 & YOUNTS PK. 700 5 Na S) \iaron’ \ bs 62-40 FREMONTS PK. 13790 ry NEWFORK PK. Rectangle 56 AWASHAKIE NEEDLE > MT tote vont Ih/B'T'S\ 13000 ‘py Dd 5 Qe } % 13249 cS a i NS. CROWHEART BUTTE \ DEPARTMENT OF THE INTERIOR U.S.GEOLOGICAL AND GEOGRAPHICAL SURVEY OF THE TERRITORIES F.V.HAYDEN,U.S.GEOLOGIST IN CHARGE. SHOWING PORTIONS OF PRIMARY BY A.D.Wilson. TRIANGULATION J TOPOGRAPHY BY : = al . ne Henry Gannett,G. B.Chittenden, | va > \ i | Ne ' G.R.Bechler and f.A.Clark. | ys | Ba 2 | | We ice \ oS ei. | Scale 8 miles to Linch. x & ® ona, 20a) a ae —— ——3e os (lav Walla Lake —~ A XI Christin ON9) Lake al f ——\Strawberst April 1879. 1 \ i 1 i i | Wwe enows SPPrig . 7 | Twp Ai a ame Ona a Saree 6050 _. FRMARY STAY 4. Ae é AL Mud Sp Death Livkex 2, Wee GD 6624 ——___—_—_—_ Rectangle 57 44° 30 43° 420 pesados ae Oe 5a he Ti awe i trae SANIVYOW ASIIVA NOLAL GNVYS Siletdt, IN) I “ONNOYSDAYOS EDYWANSEY SI) YSaAlY = ie) @ Vo ASAANS ie CU SANIVYOW “QNNOYSSYOH SHIN! ONVY NOLSL GNVYO 4 “NVYOW LNNOW Ver 0) 4ayMvV1SNOSM Gieses eM 9) Yn THE TERTIARY LAKE BASIN AT FLORISSANT, COLO., BETWEEN SOUTH AND HAYDEN PARKS.,* [With a map. ] By SAMUEL H. SCUDDER. The following remarks are based upon collections and notes made during a visit to Florissant, in the summer of 1877, in company with Messrs. Arthur Lakes, of Golden, Colo., and F. C. Bowditch, of Boston, Mass. As five days only were spent in the place, most of the time was given up to the collection and care of specimens, so that only a general survey of the locality was possible. Mr. Lakes especially gave himself to the study of the geology of the district, and as he was previously familiar with the structure of the surrounding country, and placed his notes at my disposal, the first part of this paper should be considered our joint production. GEOLOGY. The tertiary lake basin at Florissant, already famous for its prolific beds of plants and insects, is situated in a narrow valley high up in the mountains at the southern extremity of the Front Rarge of Colorado, at no great distance from Pike’s Peak. The first, and, so far as I am aware, the only notice of it which has been published, is that by Mr, A. C. Peale, in bis account of the geology of Hayden Park and the country lying between it and the upper cafion of the South Platte.t As it is brief, it is given here in full: “The latter {Beaver Creek] flows to the northwest, and empties into the South Platte just below the upper cafion. ‘About five miles from its mouth, around the settlement of Florissant, is an irregular basin filled with modern lake deposits. The entire basin is not more than five miles in diameter. The deposits extend up the branches of the creek, which all unite near Florissant. Between the branches are granite islands appearing above the beds, which themselves rest on the granite. Just below Florissant, on the north side of the road, are blutts not over 50 feet in height, in which are good exposures of the various beds. The following section gives them from the top downward : “1. Coarse conglomeritic sandstone. “2, Fine-grained, soft, yellowish-white sandstone, with bands that are more or less argillaceous, and containing fragments and stems of leaves. “3. Coarse gray and yellow sandstone. “4, Chocolate-colored clay shales with fossil leaves. At the upper part these shales are black, and below pass into— “5. Whitish clay shales. “These last form the base of the hill. The beds are all horizontal. “Reprinted with additions and alterations from the Bulletin of Survey, vol. vi, art. Hs t Ann. Rep. U. S. Geol. Sury. Terr. 1873, p. 210. 8vo. Washington, 1874. 271 2a GEOLOGICAL SURVEY OF THE TERRITORIES. Scattered around are fragments of a trachyte, which probably caps the beds. In one of the valieys Mr. Taggart discovered, ucar an old well, pieces of trachyte, which, on looking at the excavation, was found to be the first layer penetrated. The point of overflow from which this ma- terial came is probably to the southward, in Dr. Endlich’s district. The lake basin may possibly be one of a chain of lakes that extended south- ward. Ihad thoughtit possible that the beds were of Pliocene age. The specimens obtained from bed No. 4, of the section above, were submitted to Professor Lesquereux, who informs me that they are ‘Upper Ter- tiary.’ ‘But I do not believe, as yet, that the specimens of the Green River group, to which your species are referable, authorize the conelu- sion of Pliocene age. I rather consider it, as yet, as Upper Miocene. The species known of our Upper Tertiary are as yet too few and repre- sented in poor specimens tor definitive conclusion. Your specimens have a Myrica, a Cassia, fragments of Salix angusta (A. Br.), a Rhus, an Ulmus, and a fragment of Poa or Poacites. “The shales were so soft and friable that it was rather difficult to obtain any Specimens. “About one mile south of Florissant, at the base of a small hill of sandstone, capped with conglomerate, are 20 or 50 stumps of silicified wood. ‘this locality has been called ‘Petrified Stumps’ by the people in the vicinity. The specimens of wood are not particularly good.” This basin is shown on sheet 13 of the geological atlas of Colorado published by Dr. Hayden’s survey, and its outlines are marked with con- ‘siderable accuracy, although upon a comparatively small scale. The data upon which that sheet was constructed have formed the basis of the accompanying map, in which the limits of the basin are given with closer accuracy and in greater detail.* The point of greatest difference is in the valley of Fish Creek, where we noticed no extended prolonga- tion of the lacustrine deposits; and as the contours of Dr. Hayden’s par- ties themselves seem to forbid the probable extension of the deposits in this direction, we have closely limited them to what we saw. The ancient lake lies in the valley of the present South Fork of Twin Creek, and of the upper half of the main stream of the same after the South Fork has joined it. Following the road from South Park to Colo- rado Springs, and leaving it just above Florissant Post Office,t and then taking the track—half road, halt trail—which leads over the divide toward Cafion City, we shall pass between the Platte River and the Arkansas divide, through the entire length of the basin. This road crosses the South Platte a short distance, say a kilometer and a half, below the mouth of Twin Creek, climbs a long, gradual slope on the east bank of the river to an open, grassy glade, about 2,500 meters above the sea, and then descends a little more than three kilometers from the river to join the valley of Twin Creek. We scarcely begin the descent betore our attention is attracied by the outcropping of drab-colored shales, which continue until almost the very summit of the divide is reached and the descent toward the Arkansas begun, a traveling distance of not far from _ thirteen kilometers. By climbing a neighboring peak, thrice baptized as Crystal Mountain, Topaz Butte, and Cheops Pyramid, we obtain an admirable bird’s-eye view of the ancient lake and the surrounding region. To the southeast * The heights are given in feet. + Florissant is merely a post-office at Castello’s Ranch, which is also provided with a store, the basis of supplies for all the inhabitants within a radius of fifteen kilome- ters. One would have to look tar to find in Colorado a more comfortable hostelry than that to which ‘‘Judge” Castello will welcome us. SCUDDER. ] TERTIARY LAKE BASIN OF FLORISSANT. 2713 is Pike’s Peak; to the west South Park and the caion of the South Platte, shown by a depression ; to the extreme south, the grand canon of the Arkansas; while to the north a few sharp, ragged, granite peaks surmount the low wooded hills and ravines characteristic of the nearer region. Among these hills and ravines, and only a little broader than the rest of the latter, lies, to the south, the ancient Ilorissant Lake basin, marked by an irregular L-shaped grassy meadow, the southern balf broader and more rolling than the northwestern, the latter more broken and with deeper inlets. Recalling its ancient condition, and it will appear that this elevated lake must have been a beautiful, though shallow,* sheet of water. Topaz Butte, and a nameless lower elevation lying eight kilometers to its southwest, and which we may call Castello’s Mountain, guarded the head of the lake upon one side and the other, rising three or four hun- dred meters above its level. It was hemmed in on all sides by nearer granitic hills, whose wooded slopes came to the water’s edge; some- times, especially on the northern and eastern sides, rising abruptly, at others gradually sloping, so that reeds and flags grew in the shallow waters by the shore. The waters of the lake penetrated in deep inlets between the hills, giving it a varied and tortuous outline; although only about sixteen and a half kilometers long and very narrow, its mar- gin must have measured over seventy kilometers in extent. Still greater variety was gained by steep promontories, twenty meters or more in height, which projected abruptly into the lake from either side, nearly dividing it into a chain of three or four unequal and very irregular open ponds, running in a northwest-southeast direction, anda larger and less indented sheet, as large as the others combined, connected with the southwesternmost of the three by a narrow channel, and dotted with numerous Jong and narrow wooded islets just rising above the surface. The ancient outlet of the whole system was probably at the southern extremity; at least the marks of the lake-deposits reach within a few meters of the ridge which now separates the waters of the Platte and Arkansas; and the nature of the basin itself, the much more rapid de- scent of the present surface on the southern side of this divide, with the absence of any lacustrine deposits upon its slopes, lead to this conclusion. At the last elevation of the Rocky Mountain chain, the drainage flow of this immediate region was reversed; the elevation coming from a south- erly or southeasterly direction (perhaps from Pike’s Peak), the lake, or series of lakes, was drained dry by emptying at the northwestern ex- tremity. The drainage of the valley now flowed into a brook which fol- lowed the deeper part of its former floor, and the waters of the region have since emptied into the Platte and not the Arkansas, passing in their course between Topaz Butte and Castello’s Mountain. The promontories projecting into the lake on either side are formed. of trachyte or other volcanic lavas, apparently occurring in fissures directly athwart the general course of the northwestern or, upper series of lakes; aud masses of the same occur at many different points along the ancient shore, such as the western corner where the waters of the lake were finally discharged; in the neighborhood of Castello’s Ranch; along the eastern wall of the lowermost of the chain of upper lakes, near where the present road divides; and at points along both eastern and western walls of the lower southern lake. In general the trachytic flows seem to be confined to the edges of the lacustrine basin, but some, if not all, of the mesas or ancient islands of the southern lake have trachytic flows * The shallowness of the lake is indicated by the character of the fish, the sun crack- ing of some of the shales, and the erect sequoia stumps. 18 H 2T4 GEOLOGIGAL SURVEY OF THE TERRITORIES. over them; and toward the southern extremity of the lake a larger island will be seen upon the map, now forming a rounded hill with steep north- ern walls, crowned by heavy beds of dark trachyte, and its slopes coy-- ered with quantities of vesicular scoriae. The rough and craggy knoll immediately overlooking Castello’s Ranch, the reputed scene of Indian combats,* was witness of hotter times than those; vertical cylindrical holes, with smooth walls, in which a man could hide from sight, funnels scored by heat, mark, perhaps, the presence of former geysers; the ba- saltic rocks themselves are deeply fissured by the breaking up of the planes of divisions between the columns, affording the best protection to the Ute and Arapahoe warriors. But the very shales of the lake itself, in which the myriad plants and insects are entombed, are wholly com- posed of volcanic sand and ash; fifteen meters or more thick they lie, in alternating layers of coarser and finer material. About half of this, now lying beneath the general surface of the ground, consists of heavily bedded drab shales, with a conchoidal fracture, and totally destitute of fossils. ‘The upper half has been eroded and carried away, leaving, how- ever, the fragmentary remains of this great ash deposit clinging to the borders of the basin and surrounding the islands; a more convenient arrangement for the present explorer could not have been devised. That the source of the volcanic ashes must have been close at hand seems abundantly proved by the difference in the deposits at the extreme ends of the lake, as will be shown in the sections to be given. Not only does the thickness of the different beds differ at the two points, but it is dif- ficult to bring them into anything beyond the most general concord- ance. There are still other proofs of disturbance. Around one of the gran- itic islands in the southern lake basin the shales mentioned were capped by from one and a half to two and a half meters of sedimentary material, reaching nearly to the crown of the hill, the lowest bed of which, a little more than three decimeters thick, formed a regular horizontal strat- um of small volcanic pebbles and sand (A and B of Dr. Wadsworth’s note further on); while the part above is much coarser, resembling a breccia, and is very unevenly bedded, pitching at every possible angle, seamed, jointed, and weather-worn, curved and twisted, and inclosing pockets of fine laminated shales, also of voleanic ash, in which a few fossils are found (C of Dr. Wadsworth’s note). These beds cap the se- ries of regular and evenly stratified shales (D of the same note), and are perhaps synchronous with the disturbance which tilted and emptied the basin. The uppermost evenly bedded shales then formed the hard floor of the lake, and these contorted beds the softer, but hardening, and therefore more or less tenacious, deposits on that floor. The excavation of the filled-up basin we must presume to be due to the ordinary agencies of atmospheric erosion. The islands in the lower lake take now as then the form of the granitic nucleus; nearly all are long and narrow, but, their trend is in every direction, both across and along the valley in which they rest. Great masses of the shales still adhere equally on every side to the rocks against which they were deposited, proving that time alone and no rude agency has degraded the ancient floor of the lake. The shales in the southern basin dip to the north or northwest at an angle of about two degrees, and an examination of the map will show that the southern end of the ancient lake is now elevated nearly two hun- dred and fifty meters above the extreme northwestern point. The _ greater part of this present slope of the lake border will be found in the *Their rude fortifications still crown the summit. SCUDDER.] TERTIARY LAKE BASIN OF FLORISSANT. 275 southern half, where it cannot fail to strike the observant eve upon the spot, the southernmost margin, close to the summit of the divide, being nearly two hundred meters higher than the margin next the school-house hill. Our examination of the deposits of this lacustrine basin was principally made in a small hill, from which perhaps the largest number of fossils have been taken, lying just south of the house of Mr. Adam Hill, and upon his ranch. Like the other ancient islets of this upland lake, it now forms a mesa or flat-topped hill about ten or a dozen meters high, perhaps a hundred meters long and twenty-five broad. Around its eastern base are the famous petrified trees, huge, upright trunks, stand- ing as they grew, which are reported to have been five or six meters high at the advent of the present residents of the region. Piecemeal they have been destroyed by vandal tourists, until now not one of them rises more than a meter above the surface of the ground, and many of them are entirely leveled; but their huge size is attested by the relies, the largest of which can be seen to have been three or four meters in diameter. These gigantic trees appear to be sequoias, as far as can be told from thin sections of the wood submitted to Dr. George L. Goodale. As is well known, remains of more than one species of sequoia have been found in the shales at their base. At the opposite sloping end of this mesa a trench was dug from top to bottom to determine the character of the different layers, and the section exposed was carefully measured and studied. In the work of digging this trench we received the very ready and welcome assistance of our companion, Mr. Bowditch, and of Mr. Hill, the owner of the grounds. From what information we could gain about the wells in this neigh- borhood it would appear that the present bed of the ancient Florissant lake is entirely similar in composition for at least ten meters below the surface, consisting of heavily bedded non-fossiliferous shales, having a conchoidal fracture. Mr. Peale does not say whether the well seen by Mr. Taggart passed below the trachyte, which he says it first entered. Above these basal deposits, on the slope of the hill, we found,the fol- lowing series, from above downward, commencing with the evenly bed- ded strata: Section in southern lake. [By S. H. ScuppER and A. LakEs. ] Centimeters. 1, Finely laminated, evenly bedded, light-gray shale; plants and insects scarce ANGE POOL WA DECSET VEC ey ec jaapiaretseiavyal ) Mu vera ep lae. ive sube maar Apsara ie 3.2 2. Light-brown, soft and pliable, fine-grained sandstone; unfossiliferous.... 5 3. Coarser, ferruginous sandstone; unfossiliferous...--...----..--.2..----- 3.8 4, Resemblng No.1; leaves and insect remains ...4 522. 2 ciso. ela bencce 21 5. Hard, compact, grayish-black shale, breaking with a conchoidal fracture, seamed in the middle with a narrow strip of drab shale; fragments of TUE USY Oe sg ie er ce Se eae ae Ieee eine MIke CES oa ae amr a oc Re Se ges 28 Se Resrieinons sales mntossiiferodg si, oo sce psiotas sous hacia ve Sbiocjee oes 1.5 7. Resembling No. 5, but having no conchoidal fracture; stems of plants, in- sects, and asmall bivalve mollusks... cela Seek eee Le ee 9 8. Very fine gray ochreous shale; non-fossiliferous...-......--....--.------ 0.5 9. Drab shales, interlaminated with finely-divided paper shales of light- gray color; stems of plants, reeds, and insects........-...------------ 46 10. Crumbling ochreous shale; leaves abundant, insects rare.....-..---- ----. Po OLA SUAS ss TO LOSS Street ase ntoneetee waite oeise ee anoce Sak Loe ccccNeoe ee Geb 12. Coarse, ferruginous sandstone; no fossils.......------ .----0 enone -- eee 3,8 13. Very hard drab shales, having a conchoidal fracture and filled with nod- Biles ie CREOSEL ROT OU tas eira ep ven oh Ie aleinn cis inc debs san & areimelae oessie «dee 14, Finely laminated yellowish or drab shales; leaves and fragments of plants, SADT RO WELD CLO. etmamiia nen tna vin «ole alsiciinin pie/civia slaaieis mola alo eeiete aie 30 [=r] oe 276 GEOLOGICAL SURVEY OF THE TERRITORIES. Centimeters. - 15. Alternating layers of darker and lighter gray and brown ferruginous sand- stomes:(nofossile liao Beh Lat back a) ale en coli a et Reg 10 16. Drab shales ; leaves, seeds, and. other parts of plants, and insects, all in album dame ise kee es ree GSES i NOS ees Ee A gr c/a A 61 17. Ferruginous, porous, sandy shale; no fossils ..---....2--.---------.---- Bs 18. Dark gray and yellow shales; leaves and other parts of plants ---.-.-.... ig) 19. Interstratified shales, resembling 17 and 18; leaves and other parts of plants. wibbrinsectse: 20) 35 oe Se cl aa es Bek ela, Si eR a 17.8 20. Thickly bedded chocolate-colored shales; no HOssilg oe uals Seas 41 21. Porous yellow shale, interstratified with seams of very thin drab- idieaall Shnalests py lami se yaks SEER RY Se gS mE See EE be St i See 7.5 22. Heavily bedded chocolate-colored shales; no fossils ......-.----.----.--- 30 23. Thinly bedded drab shales; perfect leaves, with Saw and imperfect fragments of plants, and a few broken insects Te oe, ee 20 24. Thinly bedded light-drab shales, weathering very light; without fossils; PDEDSS Uae Lan Oe 2 apse ET NR Perm i MR 20 25. Thick bedded drab shales, breaking with a conchoidal fracture ; also des- PrbutelOt fOSstls ioe sees cies ke Me ae I Se ey aie Se Ut 18 26. Coarse arenaceous shale; unfossiliferous.......-...----..-----+--------- io) 27. Gray sandstone, containing decomposing fragments of some white mineral, perhaps calcite ; mo fossilee oe i Uh Maik Aes dbs vy Ua eel 178 28. Coarse, ferruginous, friable sandstone, with concretions of a softer mate- tial; fra ements Of SHOMs oh eee eI Sica GL oe ae 60 (7) 29. Thinly bedded drab shales, having a conchoidal fracture ; somewhat lig- nitic, with fragments of roots, SEG LLL GER, WA Id CES DES pe 25 30. Dark-chocolate shales, containing yellowish concretions ; filled with stems and roots of plants 2 5aek Se ee ee pe mse am aaa 25 Total thickness of evenly bedded shales (D of Dr. Wadsw orth’s note) above floor deposits... -- st a MANE SE Te AE ae SUS (meters) 6.668 The bed which has been most worked for insects and leaves, and in which they are unquestionably the most abundant and best preserved, is the thick bed, No. 16, lying half way up the hill, and composed of rapidly alternating beds of variously-colored drab shales. Below this insects were plentiful only in No. 19, and above it in Nos. 7 and 9; in other beds they occurred only rarely orin fragments. Plants were always abundant where insects were found, but also oceurred in many strata where insects were either not discovered, such as beds 18 and 21 in the lower half and bed 6 in the upper half, or were rare, as in beds 10 and 14 above the middle and bed 23 below; the coarser lignites occurred only near the base. The thickest unfossiliferous beds, Nos. 20 and 27, were almost uniform in character throughout, and did not readily split into laminae, indicat- ing an enormous shower of ashes or a mudflow at the time of their dep- osition; their character was similar to that of the floor-beds of the basin. These beds of shale vary in color from yellow to dark brown. Above _ them all lay, as already stated, from fifteen to twenty-five decimeters of coarser, more granulated sediments, all but the lower bed broken up and greatly contorted. These reached almost to the summit of the mesa, which was strewn with granitic gravel and a few pebbles of lava. Specimens of these upper irregular beds, and also of the underlying shales, were submitted to Dr. M. E. Wadsworth, of Cambridge, who caused thin seetions to be made from them, and has furnished the fol- lowing account of their microscopical structure: TUFA FROM FLORISSANT. The method and scheme of classification employed here is that briefly sketched in the Bulletin of the Museum of Comparative Zodlogy (vol. v, pp. 275-287). By this sys- tem only do we think that the inclosed fragments could be named, for they contain so few crystals that in most cases the base is the principal thing upon which the decision must rest. ‘SCUDDER. ] TERTIARY LAKE BASIN OF FLORISSANT. 271 A.—THE FINER DEPOSIT JUST ABOVE THE SHALES. A medium-grained gray tufa, containing crystal and fragments of feldspar, augite, &c., cemented by a fine earthy groundmass. In the thin section it is seen to be an epitome of the volcanic rocks of the Cordilleras. The groundmass holds fragments of basalt, andesite, trachyte, and rhyolite, with de- tached minerals derived from them. The basaltic fragments have in part a dense globulitie base porphyritically hold- ing ledge-formed plagioclase crystals and a few augite granules. Some of the basalt is quite coarsely crystallized, approaching the doleritic type. Olivine was observedin some of the fragments, but it is largely altered to a reddish-brown serpentine. Mag- netite is abundant. In many of the fragments the groundmass has decomposed to a reddish-brown mass, which is untransparent and holds clear crystals of plagicoclase. The basaltic fragments have suffered more from alteration and decomposition than any others in the tufa. Of andesite, both varieties pointed out by us (1. ¢., p. 280) occur in this tufa. The first, which is nearest the basalt in composition, has a brown glass as its base, filled with microlites. This base holds minute rectangular and oblong crystals of feldspar. Large microlites of augite and grains of magnetite were seen. Fragments of this are common, and are clear and unaltered. The second variety of andesite was seen to have a dense gray micro-felsitic base, holding ledge-formed feldspars and magnetite grains. Some contained the reddish-brown fibers of the destroyed hornblende. Frag- ments of this variety of andesite are quite abundant. The trachyte has a light gray, felty, and glassy base, some fragments showing be- sides this only faint traces of polarization caused by incipient feldspars. Other frag- ments show minute, well-formed crystals that appear to be sanidin. Grains of mag- netite occur scattered through the base. This is also quite abundant, and it, as well as the basalt and andesite, surpasses the rhyolite in amount. The rhyolite occurs in the form of a more or less clear glass, often cellular. The cells are often drawn out in the direction of the original flow, forming a fibrous struct- ure, which when of a grayish or reddish brown color resembles woody fiber. Some of the fragments contain elliptical cells, and a few shards of water-clear glass free from inclusions were seen. Many crystals, entire or broken, are scattered throughout the groundmass of the tufa. These crystals belong to plagioclase, sanidin, olivine, magnetite, augite, and quartz. But little quartz was observed; one crystal contained trichites and vapor cavities. The trichites are the same as those commonly seen in the quartz of granite, but this appears to have been derived from the lava. The feldspar contains inclu- sions of base, glass, and microlites, and through these the rock from which the feld- spar was derived can often be told. The augites have the characters of andesitic augite. A little palagonite and one crystal of microline were seen. The groundmass of the tufa is composed of comminuted and decomposed material derived from the lavas before described. In the groundmass trachytic and rhyolitic material appears to predominate. This specimen was chosen for description, as it best represented the general characters of the tufas. B.—THE COARSER DEPOSIT JUST ABOVE THE SHALES. This is more coarsely fragmental than any of the others, and is composed of a yel- lowish brown earthy groundmass, holding fragments of quartz, feldspar, basalt, d&c. Some of the fragments appear to belong to the older rocks, but none of them were seen in the section. Under the microscope the tufais similar to the first one described, but its fragments are larger and sometimes better marked. Some kaolinized feldspars and a little biotite were seen. The hornblende in the andesite is in the usual broken forms, with blackened edges. C.—A SPECIMEN FROM FINER PORTION OF THE UPPER CONTORTED BEDS. A yellowish earthy groundmass holding crystals and fragments of augite and feld- spar. On one side is a layer of fine detritus, composed of the same material as the groundmass of the more coarsely fragmentai portion. Its microscopic characters are similar to those of A, except that its materials are more decomposed and sanidin is more abundant. One kaolinized feldspar was observed. D.—THREE SPECIMENS OF THE INSECT-SHALES. These are brownish and grayish brown shales, being simply the finer material of the tufas laid down in laminae of varying thickness and coarseness. One is very thinly bedded. This voleanic material has evidently been worked over by water, but the conditions can of course best be told in the field. So far, however, ag we can judge by micro- 278 GEOLOGICAL SURVEY OF THE TERRITORIES. scopic examination, when the water commenced its work the material was in loose unconsolidated deposits. That it was thrown out as an ash, or rather deposited as a moya near its present location, is the most probable supposition. It seems, then, to have been taken up by the waves and. spread out as it is now found. The reason for this opinion is that the fragments are not worn as they would naturally be if they had been derived directly from solid rock by water action, and the decomposi- tion is not so gr°at as we should expect. The deposition appears to have been gentle but comparatively rapid, for there is no sign of violence or even of such decomposition as we should expect in slow deposition ; and showers of ashes falling on still water or a lake acting on an unconsolidated tufa bank answer best the conditions called for here. _ It is probable from the kaolinized feldspars and the macroscopic fragments of apparently older rocks that the latter are present in the tufa to some extent. This can best be explained by the supposition that it was deposited as a moya or mudflow within reach of the waters that have worked it over and deposited it in its present position. As we said before, the field evidence must be relied upon mainly in deciding such questions as these. M. EK. WADSWORTH. CAMBRIDGE, Mass., April 15, 1880. Another section, less carefully measured and noted with less detail than the other, was taken at or near the same place as Dr. Peale’s men- tioned at the beginning of this article, viz, at the extremity of one of the promontories jutting in a southwesterly direction into the middle of the upper chain of lakes, just west of the school-house* and about three kilometers west of Castello’s Ranch. The top of the hill was covered with granitic gravel and loose bowlders of dark scoriaceous trachyte; below this we found, passing, as before, from above downward, the following succession: Section in the northwestern lake. [By S. H. ScuppER and A. Lakes. ] Decimeters (estimated). 1. Finely laminated yellow-drab shales; no fossils ......-......---.------------- 12 2, Coarse decomposing yellowish shales; no fossils ...............-...----..----- 12 3. Fine compact drab shales; perfect remains of plants and insects. Passing into. 15 A, AAO XONS Sey GSS Wey INGOT Occ5 cosbes booube Cobo access Skoniedaeee dsee oeeken 6 5. Heavily bedded, coarse-grained, crumbling sandstone, of a grayish yellow and whitish color, becoming ferruginous in places; partially lignitic -.---....-.. 60 6. Chocolate and drab colored shales having a conchoidal fracture, passing below into whitish paper-like shales inclosed between coarse arenaceous laminae; PLAMbS Vamp SEC Sis Foe ee SERENE RN SN rT rete a UC ae Total thickness of shales above floor deposits. .....--.-- (Meters, estimated) 15 These measurements being estimated are undoubtedly too great. The composition of this bluff is coarser in character than that of the section in the southern extension of the lake. The lignitic beds, which have been used for quarrying purposes, contain numerous fragments of reeds and roots not well preserved. The lower portions of the section corre- spond better with the other than do the upper beds, where it is difficult to trace any correspondence; No. 3 of the northwestern seems, however, to correspond to No. 16 of the southern series. The whitish paper shales lying at the base of this appear to be entirely absent from the southern section, and the distorted beds which crown the mesa are not apparent in the bluff, or, if present, are wholly regular. A more careful and de- tailed section of the bluff (for which we had not time), and particularly the tracing of the beds along the wall of the lake, would probably bring to light better correspondences. Directly in front of Judge Castello’s house, at a level of a little more than 2,400 meters, is a bed of fossil fish. Judging from the present physical condition of the basin, its age is marked as later than the movements which closed the cretaceous epoch and earlier than the last upheaval in the tertiary, which seems to have * Not the school-house before mentioned, which lies to the south of Castello’s Rauch. SCUDDER. ] TERTIARY LAKE BASIN OF FLORISSANT. 279 taken place during or after miocene times, but there are no physical data yet at hand to warrant definite conclusions on this head. PALEONTOLOGY. The insects preserved in the Florissant basin are wonderfully numer- ous, this single locality having yielded in a single summer more than double the number of specimens which the famous localities at Oeningen, in Bavaria, furnished Heer in thirty years. Having visited both places I can testify to the greater prolificness of the Florissant beds. As a rule, the Oeningen specimens are better preserved, but in the same amount of shale we still find at Florissant a much larger number of sat- isfactory Specimens than at Oeningen, and the quarries are fifty times as extensive and far more easily worked. The examination of the immense series of specimens found at Floris- sant* has not gone far enough to yield data sufliciently definite for gen- eralization of any value, or which might not be altered or even reversed on further study. It may, nevertheless, be interesting to give a running notice of what has been observed in assorting the collection, and to make the single comparison with the Oeningen insect fauna which the number of individuals will furnish. This is indicated by the following table, based on a rough count of the Florissant specimens, but which cannot be far astray: . A Percentage of representation by— Fl poe re) Sune one ERG IMENOPLelaes eas Sa em ee ae sae ean ella aia aie eel eels foreiei= eins eiateistates 40 14 pe piers srgocebdadoo=uorsor nos abeddctostboneedod sSesecst pasa aber scone oosooas 30 7 WOLCO BLOT Aree aera se yee es cine aoe Sees See ee Mae ee ame MRR a ute 13 48 HIP Mmiip heLaes =P apes loa oe Asche tees meee pace n OG ses ae Be aces eStats cembee cee & 11 12 INGULOPLET AL coco sse 2 es es esee senate ce sect e eens csmtine seta ee ome ee 5 ily ORTHO PLOT An ee fame ta seme tees nae EE Seah Cree matics MRI Jeo ar + 3 PATACTIINTG Oaths aioe set pect Ss eM ee See fae cee 4 4 MV IANO Ae oso niseste meee ae nodes Celaeels ) S32 | 2a | 242 Ee n Im : ATTIGES NS eee eats aoe eice ne etn avers Finials isinin iaaicinig ae cle laimieleieieiaelnte 14 1 3 Saltigradae.— ; TESOL Ae) Rees cores eae matem Oe Ce pee Gate recta eeetreeuineine 2 0 0 Citigradae:—iy cosoidact seen esate cieee peta enemies ieelsseinescieeeenisisiceeine ets 0 0 IPilodromide esse eee teeter asec ne ce cerinnce neers 4 0 0 Laterigradae.— ; DA OMUISIA CS pe Peete a ee arate oneal eT ar a 21 4 3 (Uncertain—Archaea) Gilt. eee waleeeieien Lerritelariae:— Ph eraphosoidaernecse ces eee eee eae seein ee eee eseise ne i 0 0 Wiysderidessceenas-ssseeeeeee ae 14 0 1 DTASSIMES secs cenee ae teeeieiisiee 38 2 5 Tubitelariae:-—<“Agalenides ss) 2225 se jscsnleseoscwscaclececiom cousmesneeeeeeces 14 2 2 Hersiligid aes yagee sis ae Boe iene oss wnlcielonie ee erasiaie ee eet 3 0 0 fencer) PA SUNS aN nan rete aT hata we hal oda aiey atc Me eM ate tee time a OW See . : VROCONO RE) bod os on aooaoqobodeeoropoboRsusoop sEpoobpebeseb ade 1 0 0 PCULOLATIBe 5 ect did Sali ai 3 SON eC UN cu UG AGRI NAT OWN: yun ni 54 9 4 Orbitelariae:—Epeirid es ee eee eee eee a ale aalatteuieWiciyasteate e Aemiseeice 16 3 14 Here, it appears at a glance that exactly the same groups are repre- sented in the stratified deposits of Europe and America in every instance, excepting the Dysderides, which is unrepresented in Europe, and has a single member in America. It also appears that just those families which are represented abundantly in amber are also represented, to “Report has just come of a discovery of a considerable number of scorpions in the carboniferous rocks of Scotland, adding several species to those already known. SCUDDER. ] TERTIARY LAKE BASIN OF FLORISSANT. 287 some extent, in the American fauna, and (excepting, as before, the Dys- derides) in the European rocks. Exception should perhaps be made for the six species of the remarkable amber genus, Archaea, the posi- tion of which in the Laterigradaeis uncertain, and so marked in the ta- ble above. The relation brought out by this table is certainly striking, but it should, at the same time, be noticed that the Drassides and The- ridides, and especially the latter, are enormously represented in the Baltic amber, and, in comparison with them (though not by any means to the same extent in comparison with the other groups), feebly repre- sented in the stratified deposits of Europe and America. A comparison of the percentage of representation of the larger groups in the different horizons of tertiary times in Europe with that of Floris- sant seems to indicate a greater difference between the latter deposits and those of the upper miocene of Oeningen than between the same and either the lower miocene of Rott or the upper eocene of Aix and the Baltic amber; and although the proportionate numbers of Tubitelariae and Orbitelariae of Florissant, and especially the former, are more nearly like those of Rott, the representation of the groups in general allies Florissant on the whole with the upper eocene rather than with the lower miocene of Europe. Of extinet genera there have certainly been proposed a very large number for the European Araneidae, more than half the genera to which the species have been referred having been described as new and pe- culiar to tertiary times; these genera include about two-fifths of the species. Among the genera are some remarkable forms, such as Archaea and Mizalia, each of which is considered by Thorell and others as repre- senting a distinct family. Two only of the thirteen genera into which the American species fall are new, and to them are referred 7 of the 32 species. Other genera, not before recognized in a fossil state, occur- ring in American strata are Titanoeca, Tetrognatha, and Nephila. To enter into brief particulars on this point, 71 genera of Araneidae are now known from the tertiaries, 66 from Europe and 13 from America, 8 being common to both; of these genera, 37 are accounted extinct, 35 from Europe and 2 from America, none of these being found in both coun- tries. As may be supposed, the European genera are largely composed of amber species, no less than 52, including 32 extinct genera, being con- fined to amber deposits, which also contain other genera in common with the stratified deposits. To review rapidly the different forms of spiders found at Florissant, we may first call attention to a new genus, Parattus, to which the three species of Attides are referred; the fossil species of this family hitherto recorded are all confined to amber excepting one, Attoides eresiformis from Aix; one of the amber genera is Gorgopis, including nearly half the 12 species, a genus allied to Phidippus, richly represented to-day in North America; and it is interesting to find that Parattus, although a very aberrant form, with four large eyes instead of two, is more nearly related to Gorgopis than to any other genus. All but four of the 21 fossil Thomisinae thus far described come from amber, among them one Thomisus; Oeningen also furnishes two species of this genus and Rott another, with a Xysticus; three species of Thomisus come from Floris- sant. The three families of Tubitelariae which are represented in the European and American strata are the ones most abundant at the pres- ent day. The fossil Dysderides of Europe (16 sp.) are all from amber, and include 8 species of Segestria, into which the single species from Floris- sant falls. The Drassides are very abundant in the European amber, and our own fauna shows four species of Clubiona and one of Anyphaena, 288 GEOLOGICAL SURVEY OF THE TERRITORIES. both genera represented in amber, and Clubiona (which has eight am- ber species) also at Oeningen. Six genera of Agalenides are found in the European tertiaries, and Florissant adds another, Titanoeca (with two species) not found there, but allied to Amaurobius, which has three am- ber species. There is no family of spiders so abundantly represented in tertiary deposits as the Theridides, more than a fourth of the European species belonging here, with fourteen genera. America is for once poorer here than the stratified deposits of Hurope, but possesses a single species of Linyphia, two of Theridium, and some egg cocoons referred for con- venience to the comprehensive genus Aranea; Linyphia possesses three species from amber and two from Rott; Theridium is one of the very richest of the amber genera, having sixteen species, while three other species are described from Oeningen and Aix. The proportion of repre- sentation is very different in the Epeirides, eight per cent. of the Kuro- pean fossil spiders belonging in this group, while the proportion in America is forty-four per cent; Florissant possessing even more species than the amber, including seven or more species of Epeira, one each of Tetragnatha and Nephila, neither of which have before been found fossil, and four of a new genus, Tethneus, remarkable for its stout front legs. Five species of Epeira are reported from the European tertiaries, two each from amber and from Rott, and one from Oeningen. Not only, then, is Florissant peculiar for its richness in species of this family, but no other group of spiders shows so many novelties for the tertiary fauna. The only Myriapod is a large species of Iulus, represented by half a dozen fragments, in which only the body segments are preserved. Finally there is an odd form of animal, which although abundant and tolerably preserved is still of doubtful position. It is flattened onisci- form in shape, the body generally arched, and appears to be formed of only four nearly equal segments; each of the first three bears a pair of long swimming (?) legs, bearing a two-jointed tarsus armed with a single claw; both femur and tibia are compressed, expanded, and the latter fringed with hairs. The first segment has a median slit anteriorly, but there is no sign of a head on the 30 or 40 specimens examined, although the anterior portion of the alimentary canal appears to be extensile, being frequently preserved as protruding beyond the limits of the body and armed at the tip with a broken chitinous ring. There are no other mouth parts nor signs of eyes or antenne. The abdomen is furnished at tip with a set of harder converging parts, which look as if they served the purpose of dragging the body backward. Liurvae of any sort are exceedingly rare in the Florissant deposits, and there is no group known to me to which this seems to bear any simiitude. There are sometimes faint indications of several joints to the abdomen, but when closely examined these appear to be illusory; and this would certainly exclude it from the Crustacea, unless indeed it belonged, as has been suggested to me by Prof. A. Hyatt, to a parasitic type. It is from 8 to 10™ long. Animal remains besides those of insects are rare at Florissant. The most abundant is a species of thin-shelled Planorbis, which is not un- common, and always occurs in a more or less crushed condition; it is the only mollusk yet found there (excepting a Physa or allied form and a single small specimen of a bivalve, referred to above in the section from the southern lake), and according to Dr. C. A. White is probably undescribed, although very similar to a species found in the Green River shales, differing from it principally in its smaller size. Fishes rank next in numbers. Eight species have been found, be- - longing to four genera; of Amiidae we have Amia scutata and A. dicty- s¢uDDER.] TERTIARY LAKE BASIN OF FLORISSANT. 289 ocephala ; of Cyprinodonts, Trichophanes foliarum and T. Copei; of Catostomidae, Amyzon pandatum, A. commune, and A. fusiforme ; and of Siluridae, Khineastes pectinatus. All the species have been described by. Cope* excepting TY. Copei, which was published by Osborn, Scott, and Speir. Several bird’s feathers have been found in these beds, and a single tolerably perfect Passerine bird, with bones and feathers, has been de- scribed by Mr. J. A. Allen under the name of Palaeospiza bella, and admirably illustrated by Blake. No other figure of a Florissant animal has yet been published. Besides these, Professor Cope has just de- scribed a plover, Charedinus sheppardianus, and writes that a finch is also found in these beds. The plants, although less abundant than the insects, are exceedingly numerous, several thousand specimens having already passed through the hands of Mr. Leo Lesquereux. Of these he has published 37 species in his Tertiary Flora,t about two-fifths of which are considered iden- tical with forms from the European Tertiaries. Of other specimens which he received after the publication of that volume, he has already given a cursory account in the annual report of Dr. Hayden’s survey for 1876. He has also mentioned others in his review of Saporta’s Monde - des Plantes, and still others in letters. From these sources and from memoranda communicated by him, based on the plates of the Florissant species prepared for the eighth volume of Hayden’s Report, the follow- ing review is drawn: Among the exogenous plants the following polypetalous families are represented: Some flowers with long stamens are referred doubtfully to the genus Bombax, one of the Malvaceae. Of Tiliaceae, a species of Tilia has been found; of Rutaceae, one species of Ailanthus. Of Anacardiaceae, three species of Rhus are described under the names Hvansi, rosae- Jfolia, and Haydeni, and three or four others mentioned. Of Juglandeae one species, and one of Zanthoxyleae. Of Rhamnaceae, Paliurus Floris- santi is the only species. A few leaves of Celastrus represent the Celas- traceae. The Sapindaceae are very abundant, three genera occurring; leaves of Staphylea acuminata, numerous specimens of Sapindus stellar- iacfolius and S. angustifolius, as well as of two or three other species of the same genus, and two species of Acer, represented by flowers, leaves, and fruit. The flora has a large number of Leguminosae, of the genera Robinia, Colutea, and Cassia, besides Acacia septentrionalis and Mimosites lineartfolius, described in the report mentioned. The Rosa- ceae show a Prunus, leaves of Rosa, and species of Spiraea, with very finely preserved leaves of an Amelanchier, scarcely distinguishable from some of the varieties of the living species. Liquidambar europaeum Al. Br. represents the Hamamelidae; numerous leaves of Weinmannia, the Corniculeae; and, finally, there is a single species of Araliaceae, closely allied to Aralia multifida Sap. Excepting the Liquidambar none of the Polypetalae have been shown to be identical with European forms. Among the monopetalous plants the Ericaceae are represented by Vaccinium reticulatum Al. Br., together with one or two species of Andro- meda. Two species of [lex,one described as J. subdenticulata, represent the Aquifoliaceae; one of Diospyros, the Ebenaceae; a species of Catalpa, the Bignonaceae. Oleaceae have a flowering branch of Olea’and four species of Fraxinus, one referred to Heer’s F’. praedicta and another de- scribed as new under the name of F. Brownelli. The apetalous angiosperms show a great variety of forms at Floris- *See Bull. U. 8S. Geol. Surv. Terr., 2d ser., No. 1, pp. 3-5, 1875. t Report U. 8. Geol. Sury. Terr., vol. 7, 4to, Washington, 1878, 19H 290 GEOLOGICAL SURVEY OF THE TERRITORIES. ’ sant, and among them many are referred to species from foreign tertia- ries. Urticacea are the most numerous of all plants; three species of Ulmus occur, U. tenuinervis Lesq., peculiar to Florissant, U. Braunti Heer, and U. Fischert Heer, both found in the European Tertiaries; of Celtis there are leaves having a close affinity to the existing C. occidentalis and its variety integrifolia Nutt.; they may, however, represent two species; a single species of Ficus represents a European form, F. lan- ceolata Heer; but the mass of specimens—nearly or quite one-half of all that have been brought from this locality—represent species of Pla- nera; Lesquereux states that he has at least two thousand specimens of “leaves of Planera longifolia [Lesq.| and of its varieties, which come near Planert Ungeri [Ettingsh.], and perhaps another species of the same genus.” The Juglandaceae are represented by single specimens of Juglans thermalis* and Pterocarya americana, besides species of Pal- aeocarya and Engelhardtia. The six Cupuliferae recorded are all Euro- pean species, viz: Quercus neriifolia Al. Br., Q. drymeja Ung., Q. salicina Sap., Y. antecedens Sap., Carpinus grannis Ung., and C. pyramidalis Heer. The Myricaceae are the next most abundant type after Planera, being represented especially by Myrica acuminata Ung., and Callicoma micro- * phylla Kttingsh. (a true Myrica), both European species; there are, be- sides, no less than seven other species of Myrica, one of them referable to the European species, M7. Ludviigt Schimp., another to a variety, acuti- loba, of another European species, M. latiloba Heer; but the others new and either considered allied to M. Zacchariensis Sap. and M.arguta Sap. of the beds at Aix in Provence, or described under the names M. Copeana, M. Bolanderi, and M. insignis ; of the last, two specimens are mentioned; of the other two, only one. Of Betulaceae, Betula and Alnus are represented by a single species each, Betula dryadum Brongn. and Alnus Kefersteintti Gopp., both again European forms; cones of the latter are found. Salicaceae are tolerably abundant, Salix and Populus being represented by four species each; the four species of Salix are all identified as belonging to forms previously described from Europe or Alaska, viz: S. Lavatert Heer, S. integra Gopp., S. media Heer, and S. varians Gopp.; one species of Populus is referred to P. latior Al. Br., of the variety represented by Heer as denticulata ; two others are consid- ered new, one belonging to the section of P. glandulifera Heer ; while the fourth, represented by a large number of leaves, very variable, espe- cially in size, is considered as identical with P. Heerii Sap. of the gypsum beds of Aix. Finally, of undetermined plants in this group there is a species of Trilobium, and a Carpites, described as C. Pealei. Among the Coniferae there is considerable variety, five species occur- ring, of four genera, all but one of the species represented in the Euro- pean flora. There is, first, Pinus palaeostrobus? Ettingsh.; next, well- preserved branches of Taxodium distichum miocenicum Heer; and abun- dant remains of Glyptostrobus Europaecus Heer; as well as two species of Sequoia, 8. Langsdorfit Brongn., and S. affinis Lesq. The presence of the last-named genus is also well attested by the remains of gigantic silicified trunks in an erect position. Finally, in the lower orders of plants, the following have been found : Of the Palms, a large specimen of a Sabal related to Sabal major Ung. of the European miocene; of the Araceae, Acorus brachystachys Heer, first described from Spitzenberg; of the Typhaceae, finely preserved leaves of a Typha; of the Naiadaceae, two species of Potamegeton ; of the Iridaceae, well-preserved leaves of an Iris; of the Gramineae, ‘two frag- #66 _”* “Hot Springs, Middle Park,” is the locality given in the text of Lesquereux’s Ter- tiary Flora, but in the table, p. 327, it is also credited to Florissant, SCUDDER. ] TERTIARY LAKE BASIN OF FLORISSANT. 291 ments of leaves of Phragmites; of Filices, numerous specimens of a single species; of Rhizocarpae, many specimens of Salvinia Alleni, de- scribed from Florissant and Elko, Nev.; of Musci, Hypnum Haydeni, likewise known only from this locality; and of Characeae, two speci- mens of a Chara. Mr. Lesquereux has also found large numbers of leaves of a peculiar plant without any kind of neuration, which is apparently referable to the Proteeae. We have thus from 90 to 100 species of plants already recognized from these Florissant beds, of which nearly half the species belong to the apetalous exogens. About 40 of the species are figured in the Tertiary Flora of Lesquereux. According to this writer, such an assemblage of plants indicates a climate like that of the northern shores of the Gulf of Mexico at our epoch. ‘The preponderance of conifers, of shrubs, * * * of trees of small size, * * * gives tothe flora a general aspect which recalls that of the vegetation of uplands or valleys of mountains.” Palms are almost entirely absent, only a single specimen of one species of Sabal having occurred. “Theleaves of some species are extremely numerous, none of them crumpled, folded, or rolled, as if driven by currents, but flat, as if they had been imbedded in the muddy surface of the bottom when falling from the trees or shrubs along the borders of a lake.” It is remarkable for the almost complete absence of hard fruits; and this, with the presence of flowers, of unripe carpels of elm and maple, and of well-preserved branches of Taxodium, which in the living species “are mostly detached and thrown upon the ground in winter time or early spring,” led Mr. Lesquereux to believe that the deposition of the vegetable materials took place in the spring time, and that the lake gradually dried during summer. To this we may add that the occurrence of Acorus, of Typha, and es- pecially of Potamogeton, leads to the conclusion that the water of the lake was fresh, and not saline or brackish, equally proved by the fish, according to Cope, and by the presence of larvae of Odonata and other insects whose earlier stages are passed only in fresh water. Neither the groups of fishes which have been found, nor the water- plants, the water-insects, nor the mollusks exclude Mr. Lesquereux’s suggestion of the annual drying of the body of the lake. Moreover, cer- tain thin layers are found overlying coarser deposits, which are sun- cracked through and through; but on the other hand the thickness of the paper shales, upon which most of the fossil remains are found, and which are composed of uniform layers of triturated flakes of volcanic products, being necessarily the result of the long-continued action of water, excludes this idea. The structure of the rocks rather indicates a quiet deposition of the materials in an unruffled lake through long periods, interrupted at intervals by the influx of new lava-flows or the burying of the bottom sediments beneath heavy showers of volcanic ashes. The testimony of the few fishes to the climate of the time is not unlike that of the plants, suggesting a climate, as Professor Cope informs me, like that at present found in latitude 35° in the United States; while the insects, from which, when they are completely studied, we may cer- tainly draw more definite conclusions, appear from their general ensem- ble to prove the same or a somewhat warmer climate. If we inquire what testimony the fossil spiders of Florissant bear to the climate of that district in tertiary times, there is only one answer to be given; the present distribution of their allies certainly points to a considerably 292 GEOLOGICAL SURVEY OF THE TERRITORIES. warmer climate than now—a climate which may, perhaps, best be com- pared to the middle zone of our Southern States. The known living species of the genera to which they belong are in general credited to re- gions like Georgia in this country and the two shores of the Mediter- ranean in Europe. The presence of species of Theridium, Linyphia, Tethneus, and Epeira, including two-fifths of the species, has no special significance; but Thomisus, Segestria, Clubiona, Anythaena, and Tita- noeca, and especially Parattus, Tetragnatha, and Nephila, certainly pre- sent an ensemble, the indications of which cannot be overlooked. White ants are essentially a tropical family, only one or two out of eighty known species occurring north of latitude 40°. In North America only three have been recorded north of the border of the Gulf of Mexico, ex- cepting on the Pacific coast, where one or two more extend as far as San Francisco. Two species, both belonging to the second section, are found in the valleys below Florissant, in 39° north latitude. Florissant itself is situated 2,500 meters above the sea, and the presence of so con- siderable a number of white ants imbedded in its shales is indicative of a much warmer climate at the time of their entombment than the locality now enjoys. So, too, the occurrence among other Neuroptera, of Raphi- dia and Inocellia, of Lithagrion, and probably of the peculiar forms of Agrion, bears similar testimony; and the discovery of so many genera represented in or allied to those found in the Prussian amber is also in- dicative of a much warmer climate, since the amber fauna itself is held to show, for that period and place, a climate not far removed from that of the two borders of the Mediterranean. Investigation of other forms increases the weight of this evidence at every step, for nearly all the species (very few, certainly, as yet) which have been carefully studied are found to be tropical or subtropical in nature. As, however, a large proportion of those studied have been selected for some striking feature, too much weight should not -be given to this evidence. As noted above, the superabundance of specimens of single species of plants (Planera and Myrica) is repeated in the insects, where certain species of Formicidae among Hymenoptera, of Bibionidae among Dip- tera, of Cercopida and of Alydina among Hemiptera are to be counted by fifties and hundreds. The only other general feature which may already be noted among the insects is an unexpected paucity of aquatic larvae or the imagos of water-insects. Hardly a dozen neuropterous larvae have come to hand, very few aquatic Hemiptera in any stage, and of Hydrophilidae and other water-beetles no great number. The paucity of neuropterous larvae is the more remarkable from the abundance of Phryganidae, while not a single larva-case has been found. As to the age of these deposits, the opinions of Mr. Lesquereux, based on the study of tertiary plants, and of Professor Cope, drawn from his knowledge of tertiary fishes, are far more harmonious than one would expect from their known divergence of view concerning the testimony of the fossils to the age of other tertiary beds in the West. Such dis- parity of ideas did hold at first, Mr. Lesquereux maintaining in his ear- lier notices of the flora the probability of its later miocene age; in the Tertiary Flora he placed it in the “Upper Green River ” division of his “fourth group,” together with the flora of Elko, Nev., the Green River beds being placed directly beneath them. In Hayden’s report for 1876 he refers the Florissant deposits to the upper miocene. In his review of Saporta’s Monde des Plantes,* while still considering it as miocene, he points out certain important relations which it bears to the flora of *Am., Journ. Se. (3), xvii, 279. (1879.) TERTIARY TAKE BASIN FLORISSANT, COLORADO. ——:0: Portions shaded with vertical lines re ae bed of the ancient lake; with lique lines, the points of lay va eae The oblo} ong black spots represent the f lands Scale: 1 mile to 1 inch Co; tours : 200 feet. 4 Fic. 6.—Limnetis brevifrons, a, out- Frons, frontof female, great- size and half as long as line of shell; b, front of head of female. ly enlarged. Lindahl del. the entire limb, while the Lindahl del. lower division of the flabellum, that next to the hand, is rather broader and larger than in ZL. gould. In the female the upper division of the flabellum (br') isshort and broad ; the gillis very long; the lower division of the flabellum (Plate XX VII, fig. 2 a) is as in LZ. mucronatus ; the 4th endite is long and narrow, while the 5th is longer than the 6th. Terminal segment less prominent than in L. mucronatus, while the dorsal edge is less excurved. Average size of most of the specimens: Length, 4™™; breadth, 34™™. Several larger examples were 6™™ long and 5™™ broad. Hillis, Kans., June-28 and 29, Dr. L. Watson, in pools, associated with several other species of Phyllopods.. A few eggs were contained in inost of them. This is the largest species known, and is as a rule flat- ter and more triangular than any other species, while the truncate front of the head of the male is shorter and broader than in any other American species yet known. LIMNETIS GRACILICORNIS Packard. Limnetis gracilicornis Packard. Amer. Jour. Se., 3d ser., vol. ii, Aug., 1871. This species differs from L. gouldit in the longer and slenderer 2d an. tenne, the flagella of which are 20-jomted; the keel on the front of the head does not reach to the front edge, while in L. gouldi it does. (Fig. 3, b.) Shell of the same form, but much larger than in L. gouldit. Length of shell, 4.2™™; breadth, 4™™. Waco, Tex., with Hulimnadia texana and Streptocephalus texanus (G. W. Belfrage). I have unfortunately been unable within late years to obtain any specimens for dissection and study. PACKARD. ] PHYLLOPODS OF NORTH AMERICA. 303 Subfamily ESTHERIAN At Packard. Carapace or shell obiong, more or less flattened or oval, sometimes subglobose, with distinct lines of growth. From 18 to 27 or 28 pairs of feet; in the males the two anterior pairs of feet with hands; the end of the abdomen with dorsal spines and two pairs of very long, large, curved, terminal spines. Synopsis of the genera. Shell oval, more or less globose, with 18-22 lines of growth, amber-colored; flagella of 2d antenneze 11-17 jointed; PAsLOLA OD Ao DAtTS Ch FOOT a2 1s) Susias see t= led ci eco Estheria. Shell large, broad oval, much flattened, subtriangular, with about 18 lines of growth, a haft-organ present. Flagella of 2d antenne 12-13 jointed; 18-22 pairs of feet...... Limnadia. Shell narrow-ovate, rather prominent behind the umbones, with 4-5 lines of growth. April (G. W. Belfrage). This fine species differs from Li. morsei, its nearest ally, in having a much shorter and higher shell with the larger beaks nearer the anterior end. 310 GEOLOGICAL SURVEY OF THE TERRITORIES. ESTHERIA, JONESII Baird. Plates III, figs. 3, 5,7; XXIV, fig. 2; XXVIII, fig. 7. Estheria jonesi Baird, Proc. Zool. Soc. London, 147, Pl. XV, figs. 1, 1a, 1b, 1c, 1d, 1862. Packard, Hayden’s U. S. Geol. Surv. Terr. for 1873, 619, 1874. Shell very large, full, globose, nearly twice as thick as any of the pre- ceeding species} the beaks very large, full, and high, situated between the middle and the anterior third of the shell; dorsal edge short; shell donaciform or wedge-shaped. It also differs from all the other species in the very numerous crowded lines of growth, with a bead-like rim of coarse punctures just above each line; along the lower edge of the shell a rim of short stiff coarse sete. (Plate XXIV, fig. 2.) Seen from either end the shell is broad, heart-shaped. Second antenne stout, upper flagellum 18- the lower 17-jointed. In the first pair of legs of the male the gillis smaller than usual; the flabellum next to it is short and nearly twice as broad as in any of the other species, and the entire limb is short, and the hand also is short and stout, the claw being unusually short and thick. The telson is very short and highs. the Fic. 12.—Estheria jonesit, magnifea Upper edge with 13 pairs of coarse teeth twice. After Baird. of nearly uniform size; while a few hairs are on the basal half of the upper side of the caudal appendages. Length of shell, 14™™ ; height, 11™™; thickness, 8™™. Cuba (Dunker).—I am indebted for specimens to Dr. E. Von Martens, of the Berlin Museum. A number of specimens, which do not differ from ‘the Cuban examples, were loaned me by Dr. Stimpson, curator of the Chicago Academy, and are marked ‘Locality lost.” As no other speci- mens from the West Indies occur in the collection received from Dr. Fie. 13.—Limnadia americana, Packard. Stimpson, it indicates that H. jonesiti may possibly oceur in the Southern States, or Central America; the only habitat as yet known being Cuba, where it is said by Baird to inhabit brackish water. PACKARD. ] PHYLLOPODS OF NORTH AMERICA. 311 Genus LIMNADIA Brongniart. Limnadia Brongniart, Mémoires du Muséum d’Hist. Nat. VI, Pl. 13, 1820. Milne-Edwards, Hist. Nat. des Crustacés III, 561, 1840. Shell broad, flat, with about 18 lines of growth, disappearing near the very flat nearly obsolete beaks; 22 pairs of feet. LIMNADIA AMERICANA Morse. Limnadia americana Morse, Proc. Bost. Soc. Nat. Hist. XI. First Book of Zoology. Fig. 138, L., 1875. Shell (Fig. 13 in text) large, broad, ovate, much flattened, with 18 lines of growth; smooth and shining; allied to L. gigas of Europe. Length of Shell 2o22- breadth. O27. Museum of Peabody Academy, collected by Mr. Tufts, at Lynn, Mass. Genus EULIMNADIA Packard. Eulimnadia Packard, Sixth Report Peab. Acad. Se. Salem., 55, June, 1874. Hayden’s U. 8. Geol. and Gevgr. Surv. Rep. for 1873; 618, 1874. Shell Lee, oblong, oval, not nearly as wide as in Limnadia, with only 4 or 5 lines of erowth: the dorsal edge straighter, less curv ed than in Limnadia; 18 pairs of feet. The head and antenne do not differ essentially, but the gills are much larger than in Limnadia; while the upper or dorsal lobe of the flabellum is much smaller than in Limnadia. The Australian Limnadia stanleyana King and L. antillarum Baird are congeneric with our H. agassizti and texana. Synopsis of the Species. Shell narrow-ovate, with 4 lines of growth .....-.-- Weciees HH. agassizii. Shell narrower than in preceding, more oblong, with 5 lines of growth; 2d antenne longer, more spiney and hairy than in foregoing spe- PAC SU eat ee Fa caalbiacd i acts ee a tee: IS Bt E Le Re lira hea E. texana. EULIMNADIA AGASSIzIt Packard. Plate VII, figs. 5, 6. Eulinnadia agassizii Packard, Sixth Rep. Peab. Acad. Sc., 54, 1874. Hayden’s U. 8. Geol. and Geogr. Surv. for 1873. 618, 1874. Carapace valves whitish, very transparent, quite regularly oval, nar- rower than usual, somewhat trun- cate at the end, widest slightly in front of the middle, with four lines of growth, valves much more con vex than in Limnadia americana. Head with the “haft-organ” larger than in EH. texana. First antennz much shorter, smaller and less distinctly segmented than in LH. tevana, not reaching beyond the middle of the stem or scape of the 2d antenn, while in H. texana they reach to the basal joint of the fla- : : se Fic. 14.—Hulimnadia agassizii Packard, en- gella. Secondantenne with 9 joints larged about 6 times. to each flagellum. In the upper flagellum but a single seta at the end of each joint, while there are four or five in HL. texana ; the set on the 312 GEOLOGICAL SURVEY OF THE TERRITORIES. under side are much shorter and stouter than in ZH. texana; the stem is shorter and stouter than that of H. texana. Eighteen pairs of feet. Telson rather broad; along the dorsal edge are twelve pairs of acute spinules with the ustial lon g forked filament between the first and second pair of spines; the large terminal spines of the telson fringed with long hair-like set instead of spines, as in the Kuropean Limnadia gigas, but the tip is armed with minute short spines. A stout conspicuous spine on the lower angle of the telson under the terminal spines. A pair of long abdominal cirri. The eggs are yellowish and roughly granulated. Length of shell, 6.2™™; breadth, 3.8™™. About one hundred females, mostly with eggs, occurred in a small pool of fresh water on Penikese Island, Buzzard’s Bay, August 27, 1873, collected by Mr. Walter Faxon. Upon examining the pool the following July or August (1874), the young, about a line in length were found, but the pond subsequently dried up. ‘The eggs are yellowish and with ‘the chorion roughly granulated. The species was dedicated to Prof. L. Agassiz. Compared with L. americana Morse, which closely secouttlies DT. gigas (received from Sweden through the kindness of Prof. W. Lilljeborg), it differs very decidedly in the “much narrower shell and fewer lines of growth. It belongs toa different genus from the two above-named spe- cies, agreeing in the structure of the animal and the bivalved carapace with L. antillarum Baird, Proc. Zool. Soc., 1852, 30, from St. Demingo (ig. 15), and L. texana Pack. From LZ. antiilarwm it differs in being more regularly oval and much more prominent behind the umbones. It also agrees with Baird’s description of ZL. antillarum in its two large terminal caudal spines being hairy, it having eighteen feet and nine- jointed flagella. It differs from L. texana in the stouter haft-organ, be- ing less triangular i in outline; in the broader telson, on the upper edge of “which the teeth are less numerous : in the smalier first antennee, and the less spiny second pair; the shell differs in being more broadly ovate than in 7. texana, which is oblong, less concave along the dorsal edge, and it differs from that of H. texana in having four instead of five lines of growth, as in L. texana. EULIMNADIA TEXANA Packard. Plates VI, VII, figs. 1-4. Hulimnadia terana Packard, Amer. Jour. Sc., vol. ii, Aug. 1871. Carapace valves rounded, oval, whitish, with 5 concentric lines of growth; shell very minutely punctured; these markings being coarser at the posterior end of the shell, where they are arranged in lines parallel to the edge of the shell ; eyesdouble, but with the inner edges contiguous. Twenty body-segments behind the head, including the telson; 18 pairs of feet ; first antenne extending to the first joint of the flagella of sec- ond pair; the latter each 9-jointed, each joint above with 4 or 5 stout sete, and beneath with long spinulose sete. First pair of legs of male with a slender hand; the claw moderately large, the fifth endite very long and slender. Telson with sixteen fine teeth above, not including the terminal acute spine; caudal appendages long and slender, knife-shaped, the under edge fringed with long hairs; the upper edge straight. the end blunt, with the lower ed ge slightly curved. The eggs are yellowish and pen tagonal in outline. Length of shell, 7™™; breadth, 4™™. 08 Quite common in many places i in Western Texas in the early spring” PACKARD. ] PHYLLOPODS, OF NORTH AMERICA. 313 (G. W. Belfrage). Very common at Ellis, Kans., collected by Dr. L. Watson, and at Fort Wallace, collected by Prof. J. Lindahl. It is as- sociated with Streptocephalus texanus, Thamnocephalus brachyurus, Es- theria, compleximanus and mexicana. The shell compared with Baird’s figure of Limnadia antillarum, which belongs to this genus, and is closely allied to the present species; is more rounded oval at each end, the shell being somewhat truncated in the St. Domingo species. Species not recognizable. Limnadia coriacea Haldeman. Proc, Acad. Nat. Sc., Phil. I, 184, 1842. ‘‘ Body lengthened; swimming branchie extending along three-fourths of the inferior surface, from the neck to the extremity of the tail; tail crested above with a row of large conical obtuse tubercles; apex of the shell elevated, and about one-fourth of the length from the anterior ex- tremity; color, light brown; length, 5 millim.; height, 3; diam., 14. ‘¢ 7ab.— Ditches along the Susquehanna, in quiet water.” It is difficult to say whether this is a Limnadia or Estheria, as the de- scription is too brief and inexact to enable us to determine the genus or species. It cannot be a Limnadia, and seems to approximate more closely to Estheria; though it cannot belong to that genus, as the an- tenn are said to be 12-13 jointed. Until some one collects in the local- ities visited by Mr. Kite, we shall be in doubt as to what this form may be. Timnadella, novum genus. Charles Girard: On a new entomostracan of the family Limnadide, inhabiting the Western waters. Proceed. Academy Nat. Sciences of Philadelphia, vol. vii, 1854, 1055, page 3. “Gen. character.—EHye, one. Antenne subequal, provided upon their inferior side with long and plumose sete, whilst on the upper side there are short, slender, and simple spines. Two elongated, tape-shaped jaws. Feet in twenty-four pairs, provided upon their extremities and sides with slender and plumose setz or hairs. A series of spiny pro- cesses along the posterior half of the dorsal line. Post-abdominal plate very large. Nutritive system phlebenteric. ** Observations.—This genus differs from Limnadia in being provided with one eye only instead of two. Also by its antenne, the two pairs of which are similar in structure, whilst in Limnadia one pair is smaller than the other. The post-abdominal plate and number of feet will afford other distinguishing characters between Limnadella and Limnadia. From Cyzicus or Estheria it differs, first by the structure of the shell, which in Hstheria resembles that of an Arca, whilst in Limnadella it is altogether cyproid in its general aspect. There is a marked ditference between these two types in the structure of the antennee, the joints of which are provided on their upper part with numerous spines in Limna- della, whilst in Cyzicus there is but one single spine at the anterior edge. The structure of the feet is likewise dissimilar, being furnished with plumose setze in Limnadella.” Limnadella itei, n. spec. “ Spyecif. character.—Shell: elongated, subelliptical, thickest anteriorly ; twice as long as deep; anterior, inferior, and posterior margins regu- larly continuous; upper outline somewhat irregular on account of the 314 GEOLOGICAL SURVEY OF THE TERRITORIES. beaks being rather prominent. Valves uniformly convex. Greatest depth, one-eighth of an inch; greatest length, one-quarter of an inch. Specimens may occasionally attain to a larger size. Color, deep or ight brown, mottled with black. Animal: antenne composed each of twelve or thirteen subequal joints. Twenty-four pairs of feet, the six posterior ones diminishing gradually away so as to render the last three rudi- mentary. The last of all is inserted upon the last caudal segment but one. There is a broad subtriangular plate, terminated by two pairs of very large spines, curved upwards; the inferior pair being longer and slenderer than the upper one. The concave margin of that plate is fur- nished with a series of quite small spines. On the uppermost part of the post-abdominal plate is inserted a pair of very delicate sword-shaped appendages, very difficult to be observed even with a good microscope. Along the posterior half of the back there exists a series of sixteen pro- cesses, provided upon their upper and posterior sides with about five or Six minute-curved spines, the tip of which is bent backwards. The an- terior two of these processes are but rudimentary; the most developed occupy the middle of the series; the posterior ones again diminish gradu- ally as they approximate the post-abdominal plate. ‘Specimens collected at Cincinnati were sent to the Smithsonian In- stitution by Thomas Kite, of that city.” Afterward Professor Haldeman makes the following statement, in Proc. Acad. Nat. Se., Phil., vii, 34, 1854: ““T find that the Limnadella described by Mr. Girard, Proceed. Acad., vol. vii, page 3, is my Limnadia coriacea, ib., 1, 184, for June, 1842. At that time I doubted the propriety of placing it in Iimnadia, chiefly on account of the dorsal tubercles meutioned in my description, but I had no means of making the necessary comparisons. It was discovered in great abundance in a road-side puddle subject to dessication, and al- though I removed a number of them to a small pond, I have never met with them since.” HULIMNADIA ANTILLARUM (Baird). LTimnadia antillarum Baird. Proc. Zool. Soc. London, xx, p. 30. Plate XXIII, figs. 1, . la, 1b, le. 1852. “Carapace valves of a rounded oval shape, and of a transparent whitish color; prominent on dorsal margin where the muscular attachment of : the body takes place, sloping from thence rather suddenly towards anterior extremity, where it forms a somewhat blunt point, and more gradually to posterior extremity, which, as well as ventral margin, is rounded. Anten- nules bluntly serrated or crenulated on their upper edge, rather shorter than peduncles of large antenna, which are stout and not half Fic. 15.—EKulimnadia antillarum. the length of the body. They consist of nine Enlarged 6 diams. After Baird. articulations, each having one or two long plu- mose sete springing from the under edge, and one short stout spine at each joint on the upper edge. Caudal lamella of considerable length, and beset on under edge with long plumose setz to within a short dis- tance of the tip, which is somewhat curved, sharp-pointed, and slightly serrated on upper edge. Feet, 18 pairs. PACKARD.] PHYLLOPODS OF NORTH AMERICA. 315 “The structure of the carapace is the same as in Limnadia Hermanni, the surface being covered with minute dots or punctuations. “This species differs from the two others in the shape of the carapace and in having the sete of antennz and tail plumose. . Hab.—St. Domingo, West Indies; M. Sallé, Mus. Brit.” (Baird.) Family APODIDA Burmeister. Head and body in front broad and flat, shovel-shaped; carapace broad and flat; the body cylindrical, few or numerous segments extending beyond the carapace; antenne small, 2d pair minute, sometimes want- ing; labrum large, broad, flat; feet numerous, usually 63 pairs; with a large coxal, maxilla-like basal lobe forming gnathites; beyond five subjointed endites ; the 2-4th endites in 1st pair of feet very long and slender, especially the 5th; gill pear-shaped or bottle-shaped ; flabellum triangular, simple; the 5th endite of the Ist pair of legs is sometimes nearly as long as the body, the 11th pair bearing egg-sacs, and in the male having the genital outlet. Behind the 11th pair two of the abdomi- nal segments bear each six pairs of appendages, there being many more appendages than segments to the abdomen, while a variable number at the end are without appendages. ‘'Telson cylindrical, either short or ending (in Lepidurus) in a long paddie-like outgrowth. A pair of long filiform jointed caudal appendages. Larva a nauplius. Synopsis of the genera. Telson ending in along paddle-shaped outgrowth.........-. Lepidurus Telson short, cylindrical, simple.........-....-.--.- ap Ae Ae Apus Genus LEPIDURUS Leach. Plates XV, figs. 2, 2a, 3; XVI, figs. 1, la, 16; XVII, XXI, figs. 1-6, 9, 11. Lepidurus, Leach. Vict. des Sc. Nat. I, 259. 1816. Body rather deeper, more rounded than in Apus ; the carapace longer in proportion to the body than in Apus. Frontal doublure much as in Apus, but with a rather prominent tubercle at the base of the hypostoma, while the latter is much larger than in Apus. Eyes asin Apus, but the tubercle behind the eyes is oblong-oval, instead of round, as in all the species of Apus I have seen. Antenne much asin Apus. Mandibles as in Apus, with the same number of teeth; but the dorsal mandibular transverse tubercle on the carapace is larger; the maxille also as in Apus. The endites of the Ist pair of legs are very short, the outer ones in some species scarcely projecting beyond the edge of the carapace; there are about twelve subjoints in the 5th or longest endite, and the ends are usually (not always) rather blunt. The flabellum is very small compared with that of Apus, being narrow, triangular, the distal end acutely pointed, the gill or gill-sac itself much as in Apus. In the suc- ceeding pair of legs there are no good generic differences between Apus and Lepidurus, though endites 2-5 are inclined to be rather the longer in Lepidurus. Gnathobases or coxal lobes much alike in the two genera. In comparing the 10th pair of feet of Apus and Lepidurus no generic differences are to be observed, while the 11th pair, bearing the ovisacs, do not essentially differ in the two genera, but afford excellent specific characters; however, the ovisacs in Lepidurus are considerably jarger and deeper than in Apus. 316 GEOLOGICAL SURVEY OF THE TERRITORIES. The telson is produced behind, with a long, broad, often spatulate plate or expansion, in A. glacialis, twice as long as the body of the tel- son itself; the end subacute, or broad and rounded, or bilobed; the edge smooth or spiny. The telson itself less spiny than in Apus. The caudal stylets, or cercopoda, about as in Apus. ; The principal generic differences are in the long produced telson, the shorter endites, the usually larger carapace, being larger in proportion to the body than in Apus (though not so in L. bilobatus), and with usu- ally only from 5 to 12 abdominal segments, besides the telson, projecting beyond the hinder edge of the carapace. Geographical distribution. — Western North America appears to be richer than Hurope-Asia in the species of this genus, one (L. productus) occurring in the EKastern Hemisphere, ranging from Central Europe to Scandinavia and England, while two species occur in the central zoo- logical province of the United States, and one in Greenland and Arctie America. No species of the genus have as yet cecurred in the Missis- sippi Valley or on the Atlantic coast, and none on the Pacific coast. Synopsis of the species. A. Endites 2-5 very short, not projecting beyond the carapace. Car- apace large; telson short, pointed, spiny on edge ..... LL. glacialis. B. Endites 2-5 rather long and slender, projecting well beyond the ear- apace. Carapace large, leaving only 5 abdominal segments and telson uncovered; telson long, spatulate ............- LL. couesir. Carapace very short; telson long, bilobed............-.-- LL. bilobatus. LEPIDURUS GLACIALIS Kroyer. Plates XVI, figs. 1 (enlarged nearly 3 times), la, 1b; XVII, figs. 1,5; XXI, figs. 1, 2. L. glacialis Kroyer. Naturhistorisk Tidskrift, 2d ser. vol. ii, 431. 1847. Carapace very large, narrowing somewhat toward the eyes, being more regularly ovate than in Z. cowesii, which is more elliptical ovate. The twelve terminal abdominal segments are left uncovered by the car- apace; the telson broad at the base and extended into a blunt prolonga- tion armed with coarse teeth on the edges, and as long as the telson is. broad at base; three sharp median teeth and a finely-denticulated tu- bercle on each side, at the base; the telson and its extension are smooth beneath. The cercopoda or caudal stylets are nearly as long as the body, slender and very hairy, rather than spiny. The appendages differ decidedly from the other American species in the 2d to 5th endites being very short and broad and more equal in size ; the 5th endite is much shorter than in the other species; the third and fourth of nearly the same size and length, and one-half as long as in the two other species; the second is about twice as large in proportion as in the two other species. The scale of the sixth endite is very long and slender, the tip much attenuated, with very long, hair-like set; the gill itself narrow, pear-shaped. . In the second pair of feet the second endite is twice as fares as in the two other American species; the third and fourth of about the same size as in the other species, while the fifth is about one half as long, the scale (6th endite) very large and ensiform, with the tip curved and ending ina spine, the inner e edge with sharp spinules, the outer edge with numerous long hairs. The accessory gill is inequilaterally triangu- lar, the proximal edge straight, not produced backwards, as in the other PACKARD.] PHYLLOPODS OF NORTH AMERICA. oe two species; the fringe of hairs is very long; the gill itself is narrower than in L. couesii or bilobatus. In the tenth pair of limbs the third and fourth endites are much longer and narrower than in L. couesii, the gill and flabellum very different from the other two species, the gill being small, pyriform, with a constriction near the end, while the flabellum is nearly as broad as long, rounded anteriorly, and with the posterior edge straight. In the eleventh pair of limbs, bearing the ovisacs, the endites are also longer and narrower than in L. couesii. Length of body, 14"; of carapace, 10™™; breadth of carapace, 9™™. Length of cercopoda, "Gmm , ot telson, 13™™. Localit y.—Received from Southern Greenland, through Dr. C. F. Liit- ken; Jacobshavn, North Greenland (Gerstaecker, 1064); Cape Krusen-. stern, Arctic America (Richardson). LEPIDURUS COUESII Packard. Plates XV, figs. 2, 2a; XVII, figs. 2, 3,7; XXI, figs. 4, 5, 6, 9, 11. Lepidurus couesit Pack. American Naturalist, ix, 311, 1875. Bull. U. S. Geol. and Geogr. Survey, F. V. Hayden, in charge, iii, No. 1, 177, fig. 16. April 9, 1877. Compared with Lepidurus productus Bose of Europe, the carapace is of the same proportions, being large, broad, and leaving above five en- tire terminal abdominal segments exposed, including the telson. The denticulations on the hinder edge of the carapace are finer than in the European species, and show a tendency to become obsolete on the lower part of the incision. The eyes are slightly fuller, more prominent than in L. productus, and the interocular tubercle is smaller. The mandib- ular area of the carapace is the same as in L. productus. Labrum a little smaller than in J. productus. The feet are the same as in L. productus. The mandibles in this species (Pl. X XI, fig. 11) have, on the cutting edge, six well marked teeth, which are rather blunter, less attenuated at the end than in Apus lucasanus (fig. 12). The maxilla (Pl. XXI, fig. 9) has a three-toothed lobe externally, and the inner larger lobe is setose throughout. There are usually from ten to twelve spines on the penulti- mate segment, as in L. productus. The chief distinction lies in the very long spatulate telson, which is about twice as long in proportion as that of L. productus, and is long and narrow, varying somewhat in width, and in size. The median ridge and edge are finely spinulose, the tip is well rounded; caudal stylets nearly as Tone as in L. productus. The egos of this species, Pl. ay are somewhat larger than those of Apus lucasanus (Pl. XVIII, fig. 5; the figures of the ovisacs containing them having been drawn to the same scale by the camera lucida). From L. glacialis Kroyer, of Greenland, it differs in the longer, larger carapace, eleven terminal segments being uncovered in Te glacialis. The spines ou the excavation are much smaller; telson twice as long, and not subtriangular, and excavated at tip, as in L. glacialis; eyes larger; interocular tubercle decidedly smaller; labrum smaller. The first pairgt legs are much longer than in L. g glacialis, in which the endites are very short. Length of an average specimen from head to end of telson, 20.27; telson, 5mm: stylets, 15-19™™, This species was collected by Dr. Elliott Coues, naturalist of the United States Northern Boundary Commission. He writes me that they “occurred in myriads in several small prairie pools, from a hundred yards to a half mile or so wide, exactly on the boundary-line, 49° N., just 318 GEOLOGICAL SURVEY OF THE TERRITORIES. on the west bank of Frenchman’s River, Montana. You will noi find this stream on the map, perhaps, by this name. ‘¢ Tt is one of the first of the whole series of similar streams flowing south into Milk River. The species was not observed elsewhere. The ponds were extensive shallow sheets of sweet water, of a comfortable wading- depth, generally with a little open space in the deepest part, but mostly choked with luxuriant vegetation (Graminece, Utricularia, &e. ). Date of collection, first week in J uly, 1874.” Thirty-two males and thirty-one females were obtained by Dr. Coues: this equality in the number of the sexes is noteworthy. Several females with eggs were also obtained by C. Carrington! of Hay- den’s U. 8. Geological Survey, at Smithfield, Cache Valley, Utah. The specimens are in the Museum of the Academy of Natural Sciences, Philadelphia, to the curator of which I am indebted for the opportunity of examining the specimens. LEPIDURUS BILOBATUS Packard. Plates XV, fig. 3; XVII, figs. 4,6; XXI, fig. 3. Lepidurus bilobatus Pack., Bull. U. 8. Geol. & Geogr. Survey, F. V. Hayden, in charge, iii, No. 1, 178, Fig. 17, April 9, 1877. 10 ¢,3 2 .—Male.—Carapace broad and short; as broad as long, meas- ured along the median line. The eyes as in ZL. couesiti. The excavation in the front edge of the carapace is much larger and broader than in LZ. ceuesit, and the teeth are more numerous, but very unequal in size, there being a few large teeth, with a number of smaller ones between them. The abdomen is longer than usual, with six (and part of another) seg- ments beyond the last pair of feet, while in L. cowesti there are only five. The spines on the edges of the abdominal segments are larger than in D. coue ii, ircluding the five teeth on the edge of the segments as well as the spines. There are about sixteen segments beyond the posterior edge of the carapace; in DL. couesii, eight. On the dorsal side of the ab- dominal segments there are eight spines on the hinder edge, while there are nine in L. couesti. The species differs from any others in the re- markably short telson, which is short and broad, nearly one-half as long in proportion as in L. ‘couesii. The segment is broader at base and the telson is broader than in any other species; it is truncate at the end, and divided by a slight incision into two well-marked lobes, with about seven more or less well-marked median Spines on the blade of the tel- son; this segment, including the telson, is as long as the preceding seg- ments collectively. In the carapace, seen from “beneath, the distance from the anterior edge of the hypostoma to the anterior edge of the carapace is much less than in L. cowesit, while the hypostoma itself is much more convex. The Ist pair of legs are much longer and broader than in Z. cowesii, and the succeeding pair are rather broader than in that species. Length of body, including caudal stylets, 48™™; length of carapace (measured along median bb axe))5 Ieee breadth, gem, caudal appendages, 17§™™; Ist pair of feet, 15™™. Female. —Ditfers from the male in the much shorter body and shorter first pair of feet. There are five segments beyond the last pair of feet, and twelve segments beyond the eds ge of the carapace. It is easily dis. tinguishable by the shorter abdomen and Ist pair of feet, but other- wise it does not differ, the telson and caudal filaments being ‘of the same proportion. The egg- sacs were empty; they are situated on the tenth PACKARD.] PHYLLOPODS OF NORTH AMERICA. 319 pair of feet. Length of body, 35™™; length of carapace (measured along median line), 15™™; breadth, 17™™; length of caudal appendages, 14™™; antenne, 10™™, Po Cafion, Vermillion River, Colorado; collected by Dr. C. A. White, of Major Powell’s Survey. Described from specimens kindly loaned by Prof. H. A. Ward, of Rochester, N. Y. This exceedingly interesting species differs from any other known to me in the large, broad, bilobed telson, that of Z. glacialis being small, subtriangular, while in Z. productus and DL. couesti it is long and spatu- late. It differs from the two latter species in the longer, broader, 1st pair of feet, the longer body, and shorter carapace. The differences in the appendages in ZL. bilobatus and couesii are very slight; in the 2d pair of feet the accessory gill of LD. bilobatus is longer, less rectangularly triangular than in Z. couesii, while the pear- shaped gill is of nearly the same shape in both species. In both species the four endites are long and slender, those of Z. bilobatus being rather wider than in L. couesti. The scale (6th endite) is blunt, knife-shaped, and finely denticulate on the outside in L. bilobatus, while in L. couesia it is acute, shorter, and triangular? In the 2d pair of feet the scale in L. bilobatus is very large, stout, knife shaped, and finely denticulated on the inuer edge, with fine sete externally; that of LZ. couesti is one- third smaller and acutely triangular; the four endites are much broader in DL. bilobatus than in L. couesit. The accessory gill is larger and much the broader in L. bilobatus, the posterior end being very much produced in L.couesti. Inthe10th pairof limbs theendites are longer and narrower in L. bilobatus than in covesii, and the seale is narrower. The following exotic species may be referred to here: Lepidurus viridis Baird, Proc. Zool. Soc., London, 1850. Van Diemen’s Land. Lepidurus angusii Baird, Proc. Zool. Soc., London, 122, 1866. Rain pools on the Gaw- ler Plains, north of Adelaide, South Australia. APUS Schaeffer. Plates XV, figs. 1, 1a, 1b; XVI, figs. 2-5a; XVIII, XXXII, XXXV. Apus Schaeffer, Der krebsartige Kiefenfuss, 1756. Bose, Hist. des Crust. ii, 244, Pl. DOVE ods Latreille, Hist. des Crust. ials: iv, 195. Milne-Edwards, Hist. Nat. Crust. ill, 356, 1840. As in Lepidurus, but the carapace is shorter, the abdomen being longer and extending much farther beyond the hinder edge of the cara- pace; the 2d—5th endites of the 1st pair of legs are much longer than in Lepidurus, the 5th when stretched back sometimes reaching near the telson; the latter is short, cylindrical, without any paddle-like exten- sion. Synopsis of the species. Carapace, longer than in the other species; telson short, with 4 large centralspines SEONG ce Pe cee oe a can el ela eR ie ere A. aqualis. Carapace shorter than in equalis, but the telson longer. ..A. newberryi. Carapace shorter than in foregoing species; telson ‘With only 3 central TUTTE GS) ap Wd PAS eee Seen a cS A. lucasanus. Carapace much as in A. lucasanus; telson very short, with 5 central “TILT SR Regis gas aM ete ae tea tet aah et Diet ea wee A. longicaudatus. / => BC) GEOLOGICAL SURVEY OF THE TERRITORIES. APUS AQUALIS Packard. Plates XV, figs. 1, la, 16; XVIII, fig. 1; XIX, fig. 2; XX, fig. 2. Apus equalis Packard, Amer. Journ. Sc. Aug. 1871. Two males.—This species differs from the following species in the carapace being as long as the abdominal portion beyond it. The dou- blure is shorter than usual; while the hypostoma is rather larger, being as long as the doublure; the front of the head beneath resembling that of A. long gicaudatus. There are 17 teeth on each side of the sinus of the carapace. Eyes considerably larger than in A. longicaudatus ; the post- ocular tubercle much smaller than in the species just named. In the first pair of feet the fifth endite is rather longer than in A. newberryi, the fourth longer and slenderer, and the second also long and slender. In the second pair of feet the four endites are rather short and broad, especially the first; the “scale” (or sixth endite) is much shorter than the fifth endite, the latter being long and slender, and in one specimen reaching to the base of the telson. The fourth endite in one specimen is two-thirds as long as the fifth, in another scarcely half as long. The flabellum is smaller, but of nearly thersame form as in A. newberryi, while the gill is smailer and more regular in form. In the tenth pair of feet the four endites are rather longer and narrower than in A. newberryi ; the tips of the fifth endite and its scale are of equal length, the end of the latter terminating in a curved spine; the flabellum is much rounded, with a long fringe of hair-like seta, but is not much larger than the gill itself; telson about as long as in A. longicaudatus, unusually smooth, with five median spines, three arranged in a triangle near the edge, with two moderately prominent lateral ones at the base of the. caudal appendages, the latter moderately spiny, the spines being fine and numerous; beneath the telson is quite smooth, with fine spines in the middle and on the sides. Number of segments beyond hind edge of carapace, 23; beyond last pair of appendages, 11. Total length of the body, 29™™; length of carapace, 14™™; breadth, 12.5™™; length of carina of carapace, gum , distance from front end of keel to front edge of head, 5.2™™; ; length of caudal appendages, 19™™. Thirteen females. —Carapace with 20 spines on each side of the hinder edge or sinus. The fifth endite of the first pair of feet reaches in all the ‘Matamoras specimens but one to the base of the telson, in the others midway between the hind angle of the carapace and the base of the telson. Number of segments beyond the hind edge of shield, 25; number beyond last pair of appendages, 9. Total length of the body, 29™™; of carapace, 14%™; breadth, 11.5™™; length of keel, 8.5™™; length from end of carina to front edge of head, "5. gm. length of abdomen be- hind the carapace, 14™™; length of caudal appendages, 19mm. *Mat- amoras, Mexico, General ‘Couch, ” « Kansas, No. 5,” Mus. ‘Chicago Acad. Se., ‘Plains of Rocky Mountains, No. 390, ” Museum of Yale “College. Having been favored by Professor Baird with the opportunity of ex- amining a colored painting by Dugés, September, 1877, of an Apus col- Jected at Guanajuato, Mexico, I am inclined to refer it to A. cequalis, though in comparing the drawing with the specimens from Matamoras the antenne are represented as ‘much too short, and the body behind the carapace too thick; but it fairly represents ‘the proportions of the carapace. I have received small specimens of this species from Bosque County, Texas, through Mr. Belfrage. One of them was a young one, whose total length was 29™™, the carapace along the median line measuring ae ae PHYLLOPODS OF NORTH AMERICA. 321 11.5=™, the abdomen beyond the middle fold of the carapace being 5™™ long; the carapace was longer and the abdomen much shorter than in the adult, but in the number and arrangement of the spines on the tel- son and in the caudal stylets, as well as the eyes and adjacent parts, the Texan ones are the same as the type specimens from Kansas and Matamoras. This species may at once easily be distinguished from the other Amer- ican species by the greater length of the carapace, which equals that of the abdomen, also by the smooth telson with its five spines and the rather smooth, slightly spined caudal appendages. The young, one-half an inch in length, have the same proportions of the carapace and abdo- men as in the largest specimens. APUS NEWBERRYI Packard. Plates XVI, fig. 3, 3a, 3b; XVIII, figs. 2,7; XIX, fig. 3; XX, fig. 1. Apus newberryt Pack., Amer. Journ. Se. Aug. 1871. Carapace rather longer than in A. longicaudatus and lucasanus, tough leaving about the same number of appendages in view when seen from above. The dorsal keel of the carapace is about one-third longer than the distance between its anterior end and the front edge of the carapace. The eyes are rather larger than in A. longicaudatus, and the post-ocular tubercle is of the same form, though, owing to the larger eyes, not quite so prominent as in A. longicaudatus. The transverse muscular eminence is not so long (antero-posteriorly) as in A. longicaudatus where it is much produced posteriorly. There are 14 spines on each side of the sinus of the female carapace, the posterior angle of which is a little more obtuse than in A. longicaudatus. Doublure and hypostoma as in A. longicau- datus, the tubercle at the base of the hypostoma not so strongly marked however. ‘The fifth endite of the first pair of feet reaches only a little beyond the cephalic shield, and only as far as the basal third of the abdomen (that part not covered by the carapace), while in A. longi- caudatus it reaches as far as the middle of the abdomen. The second endite unusually small and slender; third and fourth moderately short, shorter than in A. lucasanus ; the flabellum is con- siderably prolonged and attenuated backwards, much more so than in A. lucasanus ; the gill itself is rather large and twice as wide as in A. lucasanus ; in the female there are no marginal filaments. In the sec- ond pair of feet the endites are slightly longer than in A. lucasanus, especially the first one, and they are more deeply incised or denticulated. The seale (sixth endite) is large and long, reaching to the tip of the 5th endite; it is finely spinulose, with a curved terminal spine. The tlabellum is large, as is the gill itself, which is nearly twice as broad as in A. lucasanus, and without any marginal filaments. In the tenth pair of appendages the endites are very broad, triangular; the scale longer than the 5th endite, dnd with a stout terminal spine; hairy externally and spiny on the inner edge. The flabellum and gill are unusually large. The endites of the eleventh or ovigerous pair are broader than in A. lucasanus. The under side of the abdominal segments are a little more spiny than in A. longicaudatus and A. lucasanus owing tothe secondary small spines developed on the base of each segment; above there is one less spine on each ring than in A. longicaudatus, but the same number as in A. lucasanus. The telson is longer than either in A. longicaudatus or A. lucasanus ; 21 322 GEOLOGICAL SURVEY OF THE TERRITORIES. the lateral spines are minute; along the middle line are five spines; the lateral group near the base are arranged more in a line than in A. longicaudatus, where they form a more irregular group. The under sur- face is nearly smooth compared with A. longicaudatus or A. lucasanus. The caudal appendages are two-thirds as long as the body, and gradu- ally taper towards the tips instead of being suddenly thicker at base, as in A. longicaudatus, and are much less spiny. In A. longicaudatus there are four or five large stout, broad teeth on one side, while in, the pres- ent species there are a number of minute spinules around the basal as well as the terminal segments. Number of abdominal segments beyond hind edge of carapace, 29; number of segments behind the last pair of appendages, 11. Total length of carapace, 25""; length along the middle, 193""; breadth, 21". Length of dorsal keel of carapace, 124™7; from front end of keel to front edge of head, 74™™. Length of abdomen behind the carapace, 25". Length of caudal appendages, 26™". This species differs from A. longicaudatus and A. lucasanus, to which it is nearly allied in form and in geographical range, in the longer eara- pace, and shorter abdomen with its longer telson. It need not be con- founded with A. equalis, in which the carapace is much larger and longer and the telson much shorter, while the latter species is restricted to the eastern border of the Rocky Mountain plateau and to Texas and Mexico. It differs chiefly from A. longicaudatus aud A. lucasanus in the shorter endites and much longer, smoother telson, and the smooth, almost hairy, instead of spiny caudal appendages, and in the entirely different arrangement of the spines on the telson. Locality.— Utah, J. S. Newberry, No. 1.” Two females, Mus. Chi- cago Acad. Sc. Ogden, Utah, collected by Mr. Henshaw, Wheeler’s Survey, one female. In this individual there is one less spine on the middle of the telson than in the two others, and there are only eight instead of nine segments between the telson and the last pair of append- ages. The carapace does not differ, nor do the appendages. APUS LUCASANUS Packard. Plates XVI, figs. 2, 2a, 2b; XVIII, figs. 3, 5; XIX, figs. 1, 5; XXI, figs. 7, 8, 10, 12, 13. Apus lucasanus Pack., Amer. Journ. Sc. Aug., 1871. Bull. U.8. Geol. and Geogr. Survey, iii, No. i, 171,179, April 9, 1877. Males.—This is the more aberrant of the two sexes. It is very near A. longicaudatus. The eyes and post-ocular tubercle as in A. longicau- datus ; the muscular eminence is not so much produced behind as in A. longicaudatus. Carapace a little longer than wide, with 14 teeth on each side of the posterior sinus. Doublure rather longer than in A. longicaudatus and the hypostoma a little smaller. Antenne as in A. longicaudatus. The 5th endite of Ist pair of feet are shorter than usual, often not reaching to the hind edge of the carapace, being much shorter than in any of the other American species. (It is represented as rather too long in fig. 2, Pl. XVI.) The first pair of feet and succeed- ing appendages are shorter and rather smaller than in A. longicaudatus. In the Ist pair of feet of male the 2d endite is much larger than in A. longicaudatus, the three other endites being much as in the male of A. longicaudatus ; the gill is narrow, regularly oval, and fringed with sparse, thick filaments, while the flabellum or accessory gill is full, PACKARD.] PHYLLOPODS OF NORTH AMERICA. 323 evenly rounded in front and acute behind. In the 2d pair of feet the 2d endite is larger and much stouter than in A. longicaudatus ; the scale of the 4th pair is large, broad, acutely ovate, the edges smooth, the end only reaching to the outer third of the 5th endite; the flabellum is large, rounded, oval, while the gill is much as in the first pair. In the 10th pair of appendages the endites are much as in A. longicaudatus, but slightly broader, and the scale has the same relations to the 5th endite as in A. longicaudatus. As regards the flabella, the two species, though so much alike externally, differ decidedly in form, those of A. lucasanus being larger and more rounded externally, while the gills are narrower, and provided with scattered thick filaments on the edges, which are wanting in A. longicaudatus. The under side of the telson, which is longer, is also less spiny than in A. longicaudatus, and on the upper side there are three spines in the middle instead of five, as in A. longicaudatus, with two large spines on each side. Caudal appendages less spiny than in A. longicaudatus ; their spines are blunt, and their arrangement into rows differs from that in A. longicaudatus, where the rows are arranged in twos, a row of small spines being just behind a row of large ones on the edge of the joint. Number of segments exposed behind the carapace is 33; number of abdominal segments beyond the last pair of appendages, 13. Length of body, excluding the caudal appendages, 27™™. Length of carapace, 12™™; breadth of the same, 10™™; length along the middle, 9™™. Length of the keel, 6™™; distance from front end of keel to front end of carapace, 4™™, Length of caudal appendages, 14™™. Female.—The carapace is longer and the abdomen shorter than in the male. There are 17 spines on each side of the sinus of the carapace. Telson as in the male, while the caudal appendages have smaller spines; beneath not spined, being smooth, with a row of fine teeth on the edge. The exites of the 11th ovigerous feet are decidedly shorter and broader than in A. longicaudatus. Number of segments beyond the hinder end of carapace, 29; number of segments behind the last pair of append- ages, 11. The eggs are of the same size as in LeCohte’s species; they are spherical, orange-yellow; the chorion thin, transparent; the yolk granules rather large. Total length of body, 20™"; length of carapace in the middle, 10™”. ‘Length of keel, 6°"; distance from front end of keel to front edge of carapace, 4™. Length of abdomen behind the hind edge of the carapace, 14 inches. Several males from Museum of Chicago Academy of Sciences labeled “*Cape St. Lucas, J. Xanthus, 4.” Six male specimens in a bottle received from Dr. Stimpson, and marked “ Kansas ? 5”; in the same bottle were 13 females of A. equalis. These could not be diStinguished from Cape Saint Lucas specimens. This species occurred in great abundance at Ellis, Kans., associated with the other Phyllopods trom this locality. It was collected in June by Dr. L. Watson. The specimens are not distinguishable from my types of A. lucasanus from Cape Saint Lucas, Lower California. Numerous specimens have also been received from Fort Wallace, Kansas, through Prof. Joshua Lindahl. The occurrence of this species so abundant locally in Kansas, at Cape Saint Lucas, is interesting. Fearing that some mistake had been made, I have repeatedly compared the Cape Saint Lucas specimens with nu- merous ones from Kansas, and have observed no differences; in com- 324 GEOLOGICAL SURVEY OF THE TERRITORIES. paring every part of the 1st and 2d pairs of feet of individuals from Cape Saint Lucas and Kansas no differences can be found. As the species has proved to be the most abundant and accessible of all the species in this country, the specific name is not altogether ap- propriate, still it will serve to remind one of the interesting features in its geographical distribution. The food of this species appears to be Crustacea, as in dissecting the mouth-parts of one of this species the legs of an Asellus-like Crusta- cean were found partly swallowed. Hence they are quite predaceous in their habits. APUS LONGICAUDATUS Leconte. Plates XVI figs. 4, 4a; XVIII, figs. 4, 6; XIX, fig. 4; XX, figs. 3, 4. Apus longicaudatus Lec., Annals N. Y. Lyceum, iv, 155, Pl. IX, 1846. Apus obtusus James, Long’ s Expedition, ii, 336. Packard, Hayden’ 3 U.S. Geol. Survey, Terr. Report for. 1873, 620, 1874. Carapace about as long as wide, being shorter than in any other known American species. This species, besides the characters given by Leconte, has the following: The frontal doublure is about one-half as long in proportion as in vi cancriformis, being shorter than the hypo- stoma; the latter is rather shorter and broader than in A. caneriformis, and with a swollen area or eminence at the base, not present in A. can- criformis. The antenne are two-jointed, the 2d joint slenderer, more chitinous than in A. cancriformis, and reaching to within a distance from the edge of the shield equal fo one-fourth of theirlength. The 1st pair of feet are alike in both sexes. The endites are long and slender, differing only slightly from those of A. lucasanus; the specifie differ- ences are, however, best marked in the exites of all the limbs, the gills being small, rather narrow, but still wider than in A. lucasanus, but without the fringe of coarse filaments of the latter species; the fla- bellum is shorter, more triangular, the anterior edge being less full and rounded. In the 2d pair of feet the endites are much as in A. lucasanus, but the scale is long, knife-shaped, acute, and extends nearly to the tip of the 5th endite. ‘Lhe gill is regularly rounded, ovate, and the flabel- lum is subtriangular. In the 10th pair of limbs, while the endites are much as in A. luca- sanus they are a little narrower, and while the flabellum is of nearly the same shape and size, the gill itself is much shorter and broader, being nearly round. In the 11th pair of female limbs bearing the ovisacs, the short flabella are longer and narrower than in A. equalis. ° Seen from above, 32 segments may be counted in the males (in the female, 28) beyond the edge of the carapace; and seen from beneath, there are 14 segments beyond the last pair of appendages (in the female, 10). The abdomen is unusually spiny, as also the caudal stylets, the seg- ments of the latter being well marked by the spinules, which project unusually far out. The “telson is shorter and more spiny than in A. lucasanus ; on the upper side is a median group of three spines arranged in a triangle, with a pair lower down, with three stout lateral spines, and a group of five or six spines just within the outer edge, and near _ the base of the telson; the under side is more heavily spined laterally than in A. lucasanus, and there are more numerous, finer spines on the under side of the segment next in front of the telson. PACKAND.] PHYLLOPODS OF NORTH AMERICA. 325 Total length of carapace, 19™™; width of the same, 17™™. Length of keel on the carapace, 84~™; from anterior end of keel to front edge of carapace, 6™". Length of abdomen beyond the carapace, 213". Length of caudal appendages, 20". Diameter of the ovisaes, 257". Our female differs from the males in the carapace being longer, with 28 segments, uncovered, beyond the carapace; and 10 segments bevond that bearing the last pair of appendages, while the under side of the telson is much smoother than in the males, but the upper side as in the males; the caudal appendages less spiny than in the males. The ovisaes contained a few eggs, which were of the same size as in A. lucasanus and otherwise the same, except that the germ had com- menced to develop; they were arranged in the cavity of the ovisac side by side in two rows, the lower or inner row the larger. I have had the opportunity of examining Professor Dana’s original type of Leconte’s, contained in the museum of Yale College. It was, when received, broken and dried up, but with the carapace preserved, while the caudal appendages were wanting. The specimen was labeled ‘Rocky Mountains, near Long’s Peak.” ‘This would place it within the present limits of Colorado. Four specimens from the museum of the Chicago Academy of Sciences, received through the late Dr. William Simpson, were labeled “Texas, J. H. Clark No. 3.” They only differ from Dana’s type specimen in the dorsal carina of the carapace being considerably shorter than in the type, being twice as long as the distance from the front margin of the carapace to the anterior end of the keel. In the other specimen this distance is one-third or one-fourth as great as the length of the keel. The specimens vary somewhat in the relative length of the keel, in the length of the abdomen, and the size and num- ber of spines on the under surface of the telson, while the endites of the Ist pair of feet vary slightly in length. The size and form of the telson, and the number and arrangement of the spines afford good spe- cific characters in this genus. Three specimens labeled “ Pools near Yellowstone River, Dr. Hayden, 6,” were also received through Dr. Stimpson, of the Chicago Academy. The range of the species would seem to be from the Yellowstone River along the eastern flank of the Rocky Mountains to Texas, probably the upper part of the State. James, in Long’s “ Expedition to the Rocky Mountains,” says of this species: ‘“Rain-water puddles on the Platte River, near the Rocky Mountains. . . . In rain-water puddles we remarked a new species of Branchipoda belonging to the genus Apus; small crustaceous ani- mals, which exhibit a miniature resemblance to the King or Horse-shoe Crab (Limulus polyphemus) of our own sea coast, but which are furnished with about 60 pairs of feet, and swim upon their back. The basins of water which contained them had been very much diminished by evap- oration and infiltration, and were now crowded to excess, principally with the Apus, great numbers of which were dying upon the surround- ing mud, whence the water had receded. This species is distinguished from the productus of Bose and montagui of Leach, by not having the dorsal carina prolonged in a point behind; and from caneriformis by the greater proportional width of the thorax, and more obtuse emargina- tion behind. The length of the thorax along the middle is three-tenths of an inch, and its greatest breadth somewhat more. It may be named Apus obtusus.”—Note 7, p. 336. 326 GEOLOGICAL SURVEY OF THE TERRITORIES. We should regard A. longicaudatus as standing at the head of the genus, and the Kuropean species, A. cancriformis, lowest, the former species being on the whole more specialized, since the carapace is in A. longicaudatus smaller, not reaching to the. middle of the whole body, while that of A. cancriformis is more as in the larval stages, since it reaches nearly to the telson, nearly concealing from above the limbs. The frontal doublure is also much smaller than in the European species, while in the latter species the caudal appendages are considerably longer than the body, in A. longicaudatus being barely one-half as long as the whole body. On the whole, therefore, A. longicaudatus seems nearer allied to Branchipodide, while A. cancriformis, by its large shield cover- g meatly the whole body, shows some slight approximation to the Limna- tad. APUS DOMINGENSIS Baird. “Apus Domingensis Baird, Proc. Zool. Soc. London, Part xx, 5 (Tab. 22, fig. 1), 1852. ““Clypeo corporis dimidiam partem tegente, rotundo, tenui, corneo; ramo externo pedum primi pariscorpus equante. Long. toti corporis 1 poll; lat. clypei 2 poll. “« Hab.—In Insula St. Domingo, India Occi- dentali. Collegit M. Sallé. Museum Britanni- cum. “Though a native of the West Indies, this species may be easily distinguished from A. Guildingit by its round-shaped carapace of a horny colour, covering half the body of the ani- mal, and its external branch of the first pair of feet only the length of the body, while in A. Guildingit it exceeds the whole body and caudal filament included. The carina down the center of the carapace, and the fork which it takes at the anterior extremity where the division into cephalic and thoracic portions takes place, are marked throughout their length with a deep brown color, as are also the short stout spines on the abdominal portion of the body. These are straight, not hooked, as in some of the otfer species. The caudal filaments are nearly the length of the body, and are covered with very numerous, extremely short sete. The ovipar- ous feet are present in all the specimens I have examined, but none contain any ova.” This species (Fig. 16) is very closely allied to AE ee ale A. equalis, and represents that species in the larsed. After Baird, «West Indian fauna. APUS GUILDINGII Thompson. Apus Guildingii Thompson, Zool. Researches, Fasc., v. 108, t. 6, fig. 3; Milne-Ed- wards, Hist. Nat. Crust. iii, 561. Baird, Monog. Family Apodidx, Proc. Zool. Soc. London, Pt. XX, 3, 1852. Clypeo corporis vix dimidiam partem tegente, quadrato, membranaceo, nigrescente ; ramo externo pedum primi paris longissimo, totum cor- pus, filamentis caudalibus inclusis, excedente. Hab.—In Insula “St. Vincents,” India Occidentali; Rev. Lansdowne Guilding. PACKARD.] PHYLLOPODS OF NORTH AMERICA. ond Mr. Thompson, in his Zoological Researches, remarks: “I received this species of Apus together with the Artemia Guildingii from the West Indies, and having as yet no details must leave its history in the hands of its distinguished discoverer. Itis ofa light blackish color, the clypeus translucent, almost membranous, and shorter in proportion than in any of the known species, with the extreme branch of the anterior member extremely long.” Unfortunately we have no further history of this species from its discoverer, the Rev. Lansdowne Guilding, but the short square-shaped carapace and the extreme length of the external branch of the first pair of feet sufficiently distinguish it. We add the following description of an Asiatic species, briefly de- seribed by us in 1871. APUS HIMALAYANUS Packard. Plate XVI, figs. 5, 5a. Apus himalayanus Pack. Amer. Journ. Sc. 1871. Several females.—Carapace two-thirds as long as the body, with from 14 to 16 teeth on each side of the sinus on the hind edge, the last tooth on the extreme end of the shield being more prominent than usual. Byes and post-ocular tubercle small, as in A. cancriformis ; mandibular muscular eminence behind also as in A. canecriformis ; frontal doublure, hypostoma, and appendages as in A. cancriformis. The Ist pair of feet closely resemble those of A. newberryi in the form of the long knife-like scale, as well as in the form of the gill and accessory gill (flabellum) ; the length of the 5th endite of the first pair of feet is 19"™™., and it is composed of from 72 to 80 subjoints, while A. cancriformis has about 50, and A. wqualis 42. Diameter of the ovisac is nearly 4™™ (.15 inch). There are the same number of spines on the abdominal segments as in A. can- criformis, and the spines on the telson have the same arrangement, there being on the upper side four spines at the insertion of the stylets, the 4th being minute; a single spine on the hind edge projecting over the sinus in the middle of the hind edge, which is deeper and narrower than in A. cancriformis; there is also a minute spine on each side of the sinus as in A. cancriformis, and two minute spines at the bottom of the sinus. Near the base of the telson, on each side, is an oval depression, with the posterior side raised and bearing three teeth, just as in A. can- criformis. The telson, however, is considerably longer than in A. can- criformis, being two-thirds as long as wide, while in the latter it is only one-half as long. On the under side of the telson the hind edge is rather more deeply incised than in A. cancriformis, and the edge is much more spiny, there being about 7 spines on each side. The cercopoda or caudal spines are finely spinulated, almost hairy, as in A. cancriformis, in this respect differing from all the American species. Total length of body, 25™". Greatest length of carapace, 16™. Of the keel, 117". Distance from anterior end of the keel to the front edge of the head, 5g™". Length of abdomen beyond the hind edge of carapace, 9™”. Length of caudal appendages, 28". Number of segments beyond the hind edge of the carapace, 19 (in A. cancriformis, 14). Number of segments behind the last pair of limbs, 7 (in A. canert- formis, 6). 328 GEOLOGICAL SURVEY OF THE TERRITORIES. This species belongs to the third division of the genus, of which the European cancriformis is a type, having the small eyes, and small post- ocular tubercle, while the telson is marked in the same manuer, and the caudal appendages are finely spinulose, or hairy, as in no American species. The 2d pair of feet are, however, very much like those of A. newberryt, in the torm of the long cultriform scale, or 6th endite, and in the form of the gill and its flabellum, as well as the size of the carapace. ‘¢ Collected from a stagnant pool in a jungle, four days after’a shower of rain had fallen. For five months previous to this rain there had been no rain upon the earth. Himalaya Mountains, North India, near where the Sutlege River debouches into the plains. April, 1870.” Museum of Comparative Zoology, Cambridge. This is, evidently, a high-plateau species, and a member of the Central Asiatic rather than Oriental fauna. Apus dukianus Day (Proe. Zool. See. London, p. 392, 1880) differs from A.himalayanus in the shorter carapace and much longer abdomen, which has 24 segments beyond the hinder end of the carapace, while in hima- layanus there are 17. In the Himalayan species, also, the 5th and Gth endites of the 1st pair of legs are much longer and the caudal append- ages are much longer. A. dukianus was discovered by Dr. Duke in Afghanistan, in a pond near Kelat, in April, 1877. Family BRANCHIPODIDZ Baird. Branchipoda Leach, Dict. des Se. Nat. xiv. 1816. Branchipiens Milne-Edwards, Hist. Nat. des Crust. ili, 364, 1840. Branchipuside Baird Vrans. Berwick Nat. Club, 1245. Branchipodide Fischer. Middendort’s Reise, ii, 149, 1851. Branchipodide Baird, Proc. Zod). Soc. London, 1852. Ann. and Mag. Nat. Hist. XIV, 216, 1854. Branchipide Burmeister, Organiz. of Trilobites, Roy. Soc. edit. 34. Branchipide Verrill, Proc. Amer. Assoc. Ad. Se. July, 1870. Branchipodide Packard, Report of Hayden’s U.S. Geol. Surv. Terr. for 1873, 620. 1874, Gerstaecker, Bronn’s Class. u Ord. Thierreichs, V, 1034. 1866-79. Body soft, delicate, without a carapace; head small; the eyes stalked; a distinct median ocellus; Ist antenne filiform; 2d antenne stout in the males, forming claspiug organs; frontal appendages often present ; 11.pairs of feet (19 in Polyartemia), which are without a gnathobase or coxal lobe; the other lobes (endites), especially the 5th and 6th, broad and foliaceous, with a gill and simple rounded flabellum. First and 2d uromeres with a penis in the male or an ovisac in thefemale. A specialized abdomen, with 8 to 9 segments not bearing appendages. Terminal seement bearing a pair of filamental not-jointed setose append- ages. Larva a nauplius. Subfamily 1. BRANCHIPODIN A Packard. Eleven pairs (in Polyartervia 19) of feet, with the outer endites mod- erately broad. Abdomen slender, cylindrical; terminal abdominal seg- ment with two filamental setose caudal appendages. Synopsis of the genera. a. No frontal appendages. Abdomen with eight segments; male claspers with 2d joint flat, trian- gular; ovisac short ......-..----..--- area Lae Se a alrvemerey PACKARD. ] PHYLLOPODS OF NORTH AMERICA. 329 Abdomen with nine segments; male claspers simple, cylindrical; ovisac Hones Slen@denj: tac). heehee a hula ewe 2 OF a past Branchinecta b. Frontal appendages present. Frontal appendages ribbon-like, or broad triangular; 2d joint of male claspers chitinous, simple, bent at tip -..-........--.--.-- Branchipus Second joint of male claspers long, tortuous, and forked irregularly; ovisac.lone; andislenderj weniee de saey HHL 92. Sd Ps Streptocephalus Frontal appendages long and variously lobed or spinulose; ovisac short and broad ......... SRS AI eta gti Sal Ae eveeeesee.se.- Chirocephalus Genus ARTEMIA Leach. Plates VIII, XXII, XXIII. Cancer Linneus, Systema Nat. ed. 12, i, pars. 2, 1056. Apus Schaeffer, Monogr. fig. 1, 12, 1754. Branchiopoda Lamarck, System. des Anim. sans vert. 161. 1801. Branchiopoda Latreille, Gen. Crust. et Insect, i, 22, 1806. Eulimine Latreille (pre-occeupied), * 1817. Artemia Leach, Dict. des Sc. Nat. xiv; 1819. Body very slender, with eleven pairs of feet; the head rather smaller in proportion than in the other genera of the family; the male claspers (2d antenne) very large, thin, and broad; 2-jointed, the 2d joint bent at nearly right angles upon the Ist, the latter thick, about twice as long as thick, a deep rounded sinus between the bases of the claspers ex- actly fitted so as during connection with the female to enclose her back. Near the middle, on the inner side of the 1st joint, a knob-like projection. The 2d joint simple, broad, flat, acutely triangular, from 4 to % as broad as long. The legs beyond the 5th endite rather slenderer and more pointed than in the other genera. The gill is moderately large, about half as wide as long; the flabellum broad and rounded, the edge serrate and setose as usual. The Ist endite divided into two lobes, the 2d of which is about § as long as the Ist; endites 2-4 are minute, conical; the 5th is moderately large and rounded on the outer angle, with large, coarse sete, the distal edge oblique and somewhat full and rounded; the 6th is narrow, long, and more produced and acutely pointed than usual, much more so than in Branchinecta or any other genus of the family, while the setz are much longer than in Branchinecta. Abdomen eight-jointed, very slender, ending in a pair of unusually short, small cercopods (caudal appendages) not more than twice as long as broad, being Jess than half as long asin Branchinecta, and less than half as long as the terminal segment. The male genital deeply cleft, each half long and slender, more so than in Branchipus, but somewhat as in Branchinecta, though shorter and less curved. Ovisac of the female rudely bottle-shaped, shorter and broader than in any of the other genera, with a short, broad “neck” or opening. Remarks.—This genus is in some respects simpler than Branchinecta, or any other genus of the family, and differs decidedly from any other genus, not only in the smal! size of the body, but also in the broad, flat, triangular 2d joint of the male claspers, as well as in. the much smaller, shorter caudal appendages, and the long, narrow, acute distal or 6th endites, which render the legs rather long and slender. The ovisac is also shorter and broader than usual. *According to Dr. Baird (Monograph of the Family Brancbipodide, etc., in Annals and Mag. Nat. History, xiv, 216, 1854) the genus Hulimine Latreille, 1817, was based on specimens of A. salina, which were badly preserved and erroneously described. That name was, however, pre-occupied among Acalephs, see Verrill, Observations, ete. 330 © GEOLOGICAL SURVEY OF THE TERRITORIES. Compared with the other genera, this upon the whole stands at the base of the family, though the male claspers are a little more compli- cated than in Branchinecta. Considering the fresh-water forms by them- selves, Branchinecta is, without much doubt, the lowest or simplest in structure. As seems most probable from the experiments of Schman- kevitch, Artemia is a modification of Branchinecta, and is a depauper- ated form, smaller in size, with less developed caudal appendages, due to perhaps less favorable means of obtaining food in its brine than the fresh-water forms. Hereafter, then, in diagnosing the other genera we will take Branchinecta as the simpler form, affording us a truer stand- ard of comparison than the less normal Artemia. The Siberian fresh-water genus Polyartemia of Dr. 8S. Fischer* is re- markable for possessing 19 pairs of feet; the tail is short, the ovisae quite voluminous; the male claspers are broad, flat, and consist of two branches, one covering the other; the front of the head is prolonged into a broad, very thin tentacle-like organ; in other respects it agrees with the genus Branchipus. Polyartemia forcipata Fischer was found by Middendorf in pools on the Tundra, near the rivers Taimyr and Bo- ganida, and also in Lapland, near the Tri-Ostrowa. ARTEMIA GRACILIS Verrill. Plates VIII, XXII, figs. 1, 2, 2a, 2b; XXIII. Artemia gracilis Verrill, Amer. Journ. Sc. 2d Ser. xlviii, 248, Sept. 1869. Proc. Amer. Assoc. Adv. Se. July, 1870. Artemia monica Verrill, Amer. Journ. Se. 2d Ser. xlviii, 249, Sept. 1869. Proc. Amer. Assoc. Adv. Se. July, 1870. Artemia fertilis Verrill, Amer. Journ. Sc. xviii, p. 430, Nov. 1869. Proc. Amer. Assoc. Ady. Se. July, 1870. Artemia utahensis Lockington,t Month. Micr. Journ. 137, March, 1876. This species is characterized by the slender body, its small head and small eye-stalks and eyes. The male claspers are rather slender, the 2d joint varying with age and in different individuals from the “i Same locality; it is unusually aa broadly triangular and from Fic. 17. Artemia gracilis, from Great Salt Taba A pair one-half to two-thirds as wide swimming, the male clasping its mate with the claspersaS long; at the outer angle is (0) infront ofthe ovicgo (c): elatgedahontZtines. Als a large angular projection, while (e) still more enlarged. Emerton del. the apex is acutely pointed and slightly excurved (Pl. VIII, fig. 1). The frontal knobs on the inside of the Ist or basal joint are small, rounded, button-like. The ocellus is black, trilobate. Thelegsare long and slender; the 6th endite narrow, long, and acutely triangular; the 5th endites full and rounded. The abdomen is slender, and the cercopoda very short, usually scarcely as long as one-half the width of the terminal segment of the abdomen. In color either whitish, flesh-colored, often deep red, sometimes green- ish, with black eyes. Length of male, 8-10™™ ; female, 10-12™™, For the reasons stated beyond I am disposed to unite Verrill’s A. mo- nica and A. fertilis with his first described form, A. gracilis, as I do not regard the difference he points out as more than individual; probably * Middendorf’s Sibirische Reise, Bd. II, Thl. 1, 154, 1851. +From Great Salt Lake, with a brief description. PACKARD.] PHYLLOPODS OF NORTH AMERICA. 331 they are not varietal. It appears, then, that we have but one North American species of Artemia so far as yet known. Upon comparing our species with the European it is difficult to find good differential characters, as the portions of the body where specific differences would be expected to occur are liable to considerable varia- tion. Upon comparing a number of females from Great Salt Lake with a number of females of the maleless generation from Trieste, Aus- ' tria, received from Professor Siebold, there are really no differences of ‘importance; our A. gracilis (Verrill’s fer- tilis) is Slighter, with a smaller head, and perhaps the 2d antenne are a little slighter in build; I see no essential differ- ence in the form of the ovisac, while the shape of the legs, especially the 6th en- dites, is essentially the same. The length of females (as well as males) is the same in both species. Upon comparing a good many males from Great Salt Lake with several, both stained with carmine and unstained, re- ceived from Cagliari, Sardinia, through Prof. J. McLeod, of Ghent, the European A. salina is seen to be considerably stouter, the head wider, the eve-stalks longer and larger, and the eyes larger; the frontal button-like processes of the first joint of the claspers are nearly twice as large as in the American species, and a little more pointed, while the claspers themselves are larger and stouter. The f legs and sixth endites are of about the : same form. The most apparent differ- Fic. 18.—Artemia gracilis, from New ence is in the caudal appendages or cer- Havenyscon from heneath, much entree copods, which in A. salina are several ont', 2d antenne; md, mandibles; mz, max- S : ans > - ill; pes, foot; 0, ovisac. times larger than in A. gracilis, being in the Sardinian specimens nearly three times as long and much larger than in our species. In this respect the genus shows a close affinity to Branchinecta. However, in a lot of A. salina 2 from Trieste, the cer- copods are very much shorter than in the Sardinian females, and only a little longer than in our American specimens. These appendages do not differ in the two sexes. As regards the genus in Europe, several nominal species have been described, but it seems probable that but one occurs there. As stated by Verrill in his “Observations on Phyllopod Crustacea,” in a foot-note, owing to differences in the development of the caudal lobes and sete, ‘several nominal European species, established mainly on differences in the caudal lobes and sete, are probably only the young of others, or all perhaps of A. salina, especially since those with small, caudal lobes and few or no sete, are described as small; as for example A. milhausenit, A. arietina, and A. képpeniana (Fischer species).” Verrill’s types of A. monica I have not examined, but have certainly found specimens at Great Salt Lake which agree with his description, and especially his figures of the head and male claspers. Variations in Artemia fertilis from Salt Lake-—With specimens of the sexually mature males from Great Salt Lake the description of Verrill agrees well, the claspers being very broad, the second joint being as 332 GEOLOGICAL SURVEY OF THE TERRITORIES. wide as two-thirds its length. The outer angle or elbow varies greatly, in some individuals not being noticeably produced, and with the outer edge nearly straight, while in others the angle is remarkably produced and the outer edge is much excavated. In one specimen, 7™™ in length, the claspers are one-half as wide as in another, but with the elbow still produced. In another male, 7™™ in length, selected from fifty more or less normal individuals, the elbow is enormously produced, and the claspers are small, long, narrow, and acute. In sixty other males the elbow is a good deal produced, while the claspers are broad and triangu- lar. These specimens were collected at Lake Point from the wharf, July 26, 1875, the temperature of the water under the wharf in the shade being 73° F. The females bore about 23-24 eggs in their ovisaes. Sixty red-colored males from a hot, shallow “brine pool at Farming- ton, late in July, the temperature of the water probably not less than 80° Fahr., were examined. Of these, one male, 5.5™" in length, had claspers which were even smaller and narrower than in a smaller indi- vidual, 4.5°" in length, showing an unequal degree of growth, being perhaps an example of retarded development of a secondary sexual character. A stronger example is seen in two individuals of the same length (5.5); one was very immature, the head being smaller than in the other, the claspers unusually small and narrow, the genital append- ages smaller, and the caudal appendages one- half as ‘long as in the other; in the second example the head is large and the claspers fully three times as broad as those of the first individual, being three quar- ters as broad as the space between the eyes, while the caudal append- ages were twice as long as thick, longer than those of A. gracilis, as fioured by Veryrill. This difference i in two specimens so nearly of a size shows that the sexual characters are suddenly acquired. No young were observed less than 3™ long. Identity of A. fertilis, A. gracilis, and A. monica.—On compa ing 30 males of A. gracilis from New Haven the claspers in small specimens look like Verrill’s figure of those of A. gracilis ; in large specimens like that of his figure of A. monica, the claspers increase in width with age. In two specimens of the same size and probably age, one has very narrow claspers, aS in Verrill’s figure of gracilis, in another the ciaspers are _ broader than in his figure of A. fertilis. In half-grown males the claspers are narrow, as in Verrill’s figure of A. gracilis. The forms of the caudal appendages vary with age. On comparing a few days after, to be sure that I had made no mis- take, 200 males of A. fertilis with males of A. gracilis, I could find abso- lutely no essential specific or varietal differences between these so-called species. On examining 45 females of A. gracilis from New Haven, and com- paring them with a number of Salt Lake females, no differences could be observed. Comparing with care a large female from Utah (Great Salt Lake) with one from New Haven of the same size, there was also the same proportion of parts. The eyes were ot the same size, the eye stalks of the same length; the first and second, the latter especially, had the same proportion. The feet and endites were the same, and the length of abdomen the same, though this region varies, as it irregularly contracts in alcohol. The egg-sacs in the New Haven ex- ample are a little longer and with a more acute lateral angle than in Utah examples, but this depends on age, and these differences disappear ‘In those which are of the same size and degree of sexual maturity, and in which the eggs are similarly developed. The caudal appendages in the Salt Lake example (which was 12.5"" in length) are nearly but PACKARD.] PHYLLOPODS OF NORTH AMERICA. 333 not quite so long as in New Haven ones, but there are not even varietal differences in the two examples. From these comparisons it may be inferred that the two species should be united. | On comparing a number of Salt Lake females with individuals of the same sex of the European Artemia salina, our species was found to be undoubtedly specifically distinct; the Utah specimens are sienderer, smaller, and the sixth endite of all the feet considerably slenderer and longer in proportion than in A. salina. The ovisacs were of the same proportion but slenderer, and the head is slighter and smaller in our American species. Habits of Artemia fertilis at Great Salt Lake, Utah.—The food of the Artemia appears to be the smaller fragments of brownish alge which abound in the water, especially Polycistis Packardti of Farlow.* The cells of this alga are filled with molecules of protoplasm. The contents of the alimentary canal of alcoholic specimens of Artemia is a darkish mass, which, on being examined under a 3 Tolles objective, shows the same granulated protoplasmic mass as that to be found in the lobules of the alga, leaving little doubt in my mind that the partly digested substance in the digestive canal of the Artemia is the alga. At Farmington, on the shores of the lake, where there are old brine pools, filled with strong brine, the shallow water was crowded with Artemic. The water was very warm, and the Artemic were deep red in color, though some red ones were collected in the lake itself. They were afterwards observed at Lake Point July 26, 1875. The tempera- ture of the water in the shade at the end of the wharf was 73° F. at the surface, and also at the bottom at a depth of eight feet; the temperature of the air was 80° F. at 11 a. m. Out of a large number observed, from 500 to 800 individuals, but very few were half grown, some being from + to 4 inch long. ew soli- tary males were seen, as the large majority were attached by their claspers to the females in the attitude shown in fig. 17. The females far outnumbered the males, as certainly over half of them had no males. attached. The egg-sacs and eggs were in different stages of development. I could see no attempts at copulation, unless in one instance, where a male violently jerked his body; but that was perhaps simply to obtain a stronger hold with his claspers around the body of the female, the claspers being placed just in front of the ovisac. The eggs are light, floating on the surface of the water. They are dull, dirty, yellowish white. The nauplius (Pl. X XU, fig. 1) is blood-red, with a single sapphire-red eye, and it is very active. Four sets of Artemic were observed: A. Some, both males and females, entirely green. B. Most of the females were red in front of the abdomen, the red being caused by scattered pigment cells. The males attached to them were greenish. C. Some red males attached to green females. D. The largest females entirely deep blood-red, with distended ovisacs, but contaiving no eggs. There must be numerous sterile or parthenogenous females. There is a great disproportion in the numbers of the sexes. The males are stronger swimmers than the females, darting at certain individuals and then leaving them to go after others, as if exercising some choice. * American Naturalist, Nov., 1879, p. 702. 334 GEOLOGICAL SURVEY OF THE TERRITORIES. Some males were attached to females much larger than themselves. I was told that the Artemia appears in the spring, from the middle of Apuil to May.1, and disappears during very cold weather in autumn. ARTEMIA GUILDINGII Thompson. Artemia Guildingiti Thompson. Species haec, reperta in India Occidentali, delineata est a Domino Thompson in ‘Zoological researches’ sed non descripta, necnon satis accurata delineata est. Ariemi Guildingi, Thompson Zool. Research, Fasc, 5, t. p. 11. Hab.—In insula “St. Vincents,” in India Occidentali; Rev. L. Guild- ing. “This species is figured by Mr. Thompson, but not sufficiently described to enable me to give a good diagnosis of it. It was found at St. Vincents, in the West Indies, by t the Rev. Lansdowne Guildin g, by whom its natural history was intended to have been more fully detailed. The body seems to be thick and the abdomen shorter than the body and stout; the caudal segment does not appear to be lobed nor setigerous. The cephalic segment is conical in shape, and the superior antenne, according to Mr. Thompson’s figure, consist each of four joints. The ovarian sac consists, according to the same authority, of two articula- tions.” (Baird’s Monograph of the Family Branchipodide. Annals and Mag. Nat. Hist. 2d ser. xiv, 1854, p. 226). Genus BRANCHINECTA veri Plates IX, X. Branchipus Milne-Edwards, ete. (in part). Branchinecta Verrill, Amer. Journ. Sci. 2d ser. xlvili, 250. Sept. 1869. Proc. Amer. Assoc. Ady. Se. July, 1870. Body rather long and slender, but stouter than in Artemia; head rather small, but larger than in Artemia; 2d antennz of male (claspers) with a knob on the basal joint as in Artemia; the claspers simple, quite persistent in form in the different species, not elbowed, 2-jointed, with joints cylindrical: Ist joint slightly bent; the 2d joint not bent on the first, round, and about one-half as thick as the basal joint. The 2d an- tenne of the female are rather long and slender. Labrum large and long, extended beyond the closed mandibles; the end is square, with a nipple-like projection in the middle. Eleven pairs of legs, which are shorter and broader than in Artemia. The gills are usually larger, the flabella moderately large, and quite regularly oval externally; the 1st endite and the three following are much as in Artemia, but the first is not so distinctly divided distally into a secondary lobe. The 5th is decidedly rectangular in outline, the distal edge being straight, some- times hollowed out, with rather shorter sete than in Artemia; the 6th endite in all the legs is much shorter than in Artemia, being short and broad and well rounded at the end, with rather short sete. The abdomen has nine segments, and is as long or a little longer than the head and thorax together; the cercopoda are much longer than in Artemia, and equal in length to the terminal segment, which is much shorter than in Artemia; compared with Branchipus and succeed- ing genera they are small, short, and conical. The penis is deeply _ divided into two long slender curved branches. The ovisac is cylin- drical and remarkably long and slender; in B. coloradensis nearly half as long as the abdomen, and deeply cleft at the end. PACKARD.] PHYLLOPODS OF NORTH AMERICA. 335 This genus stands in simplicity of structure next above Artemia, being related to it by its short cercopoda or caudal appendages, and the simple male claspers, with the knob-like projection at the base of each. It is less complicated than in Branchipus, and in his valuable paper on this group I hardly understand why Professor Verrill should have interposed Branchipus, his Hubranchipus, Streptocephalus, and Chirocephalus between Artemia and the present genus, as the genera in the order we place them in this essay present successive degrees of complexity from Artemia to Chirocephalus and Thamnocephalus. The Southern European Branchi- pus spinosus Nordman, from a salt lake at Odessa, appears to us, on ex- amination of a number of specimens received from Professor Siebold, to belong to this genus, contrary to Verrill’s opinion, who referred it to bis genus Hubranchipus. In this species the knob-like processes of the male claspers are present; the male claspers also are much as in B. coloradensis, but much slenderer ; the caudal appendages are short and small, as in our American species of Branchinecta, but the ovisaes are rather shorter than in any American and Arctic species, though still longer thanin Branchipus. The genus is certainly a good one, and easily distinguishable. It is especially interesting to indicate the close affin- ities of this genus to Artemia, for it is Branchinecta ferox (Fischer sp.) which Schmankevitch found to transform by artificial means into Arte- mnia, and the characters ot Branchinecta are such as we might believe a well-fed Artemia subjected also to water of suitable temperature and freshness might suddenly acquire. The fact, however, that the two genera may be artificially produced does not militate against the natural- ness of the two genera, Artemia and Branchinectes, since we can point to three American and Arctic species of Branchinecta which preserve their generic identity. As suggested by Verrill, Milne-Edwards’ Branchipus ferox (Edwards’ Crustaces, ili, 369), from fresh water near Odessa, most probably belongs to this genus. Milne-Edwards thus characterizes it: ‘‘Cornes cepha- liques sans appendice. prés du céte interne de leur base, pointues au bout et sans dent sur le bord externe. Abdomen lisse, Wei ies cau- dales longues et étroites.” It has been rediscovered in 1872 in salt pools near Odessa by Schmankevitch. Verrill also states He Bran- chipus middendorfiana Fischer, of Siberia and Lapland, may be a Bran- chinecta, and, judging by Fischer’s figures of the male clasper, the ovisae, and the cercopoda, it is without much doubt a genuine Branchinecta. By Grube and Dybowski it is regarded as a synonym of B. paludosa. It inhabits Siberia, having been collected by Middendorf near the rivers Taimyr and Boganida, as also in Lapland near Tri-Ostrowa, while it was also collected by the Ural Expedition. Hence the species of the genus Branchinecta range from the Arctic regions to Southern Russia in Eu- rope, and to the higher portions of the Rocky Mountain plateau of Colo- rado in North Ameri ica, aS Well as the plains of Kansas, the genus, with the exception of the two species living at Odessa, and B. lindahli, of Kansas, being inhabitants of Arctic and Alpine regions. Synopsis of the species. Male claspers pointed, not turned in, serrated inside of 2d joint; no G00 De CR pean Poe SO a ees ee ee ee L. paludosa. Male claspers large, end broad and bent in, with no teeth; knob EeneaT ritigs. PSE Ulad MON tee le Cad Lesa ol seek, B. coloradensis. Male claspers short; caudal appendages very long......... BL. lindahti. 336 GEOLOGICAL SURVEY OF THE TERRITORIES. BRANCHINECTA PALUDOSA (Miiller). Plate IX, figs. 1-6; Pl. X, figs. 1-5. Cancer stagnalis O. Fabr., Fauna Groen. (non Linn. et Miill. Prodr.), 247, 1780. Cancer paludosus Herbst, "Natur geschichte der Krabben. Bd. II, p. 118. Branchipus paludosus, Miller, Zool. Danica, ii, 10, Pl. 48, figs. 1-8, 1783-1806. Branchipus paludosus Reinhardt, Bidrag tilen Beskrivelse af Groenland, 1857; Pack- ard, Glacial Phenomena of Maine and Labrador, etc. Memoirs: Boston Soc. Nat. Hist. i, 295, 1867. Branchipus (Branchinecta) groenlandicus Verrill, Amer. Jour. Sc. 2d ser. xlviii, 253, Sept. 1869. Branchinecta groenlandica Verrill, Proc. Amer. Assoc. Adv. Sc., July, 1870. Branchinecta paludosus Verrill in part (Bb. arctica regarded as distinct). Branchipus middendorfianus Fischer,* Middeudorft’s Sibirische Reisen. Bd. II, p. 153. Body moderately large. Male claspers much shorter and slighter than in B. coloradensis, not reaching far beyond the middle of the thorax, basal joint more bent than in the other species, but of the same propor- tionate length, though without any knobs (also absent in immature males of 3B. coloradensis); the distal half of the inner edge with a row of fine teeth, the points ending in fine sete. 2d joint very slender, narrowing gradually to the tip, which is one-half as wide and not bent in or slightly expanded as in B. coloradensis ; 2d antenne of the female narrow and slight, at the tip suddenly contracting and ending in a mu- cronate tip. The feet are short and broad; the 5th endites, straight on the outer edge, with the outer angle rectangular, while the 6th endites are short and broad; the sete, especially at the distal angle, are rather coarser and shorter than in B. coloradensis. Caudal appendages small, narrow, scarcely longer than the terminal joint. The ovisac is oval-cylindrical, rather long, the lobes pointed at the end; only one-half as long as the abdomen. Length of body of male, 15""; length of clasper, 4°"; 2d joint, 1.5 cercopoda, en, Length of body of female, 12™"; of ovisac, 4™". The foregoing description was drawn up from an individual selected from a collection of about 80 made by Dr. Emil Bessels, at; Polaris Bay, Northern Greenland, August 1, 1872. On carefully re- examining _ after the lapse of over fifteen years, @ por- tion of the material originally collected at Labrador, and comparing a male and three females (labeled Br. aretica by Verrill) with the abundant material collected by Dr. Bessels, in Northern Greenland, I am unable to find any specific differences between them. The Greenland examples are smaller and less mature than the Labrador ones. I find that they possess the same characters as those which separate the species from B. coloradensis, and which occur in the Greenland B. paludosus. There are the same proportions in the male claspers, the knob-like processes on the basal joints are also wanting, the row of teeth on the distal half of the joint are of the same size. Owing to the greater size of the specimens the male claspers are a little larger, but the 2d jomt has the same proportions, being narrow, not widening at the tips, which also is not incurved. The ovisac is of the same length and form. ‘The penis is of the same form, and with a similar prong-like process projecting *Considered by Grube and also Dybowski as a synonym of B. paludosus. See Archiy fiir Naturgeschichte, XXVI, i, p. 201. *T have been kindly permitted by Dr. Bessels to use this material in this connection, and also the excellent drawings by Mr. Emerton, which were made originally for a report on the Natural History of the Polaris Expedition. PACKARD.] PHYLLOPODS OF NORTH AMERICA. 337 inward near the base of each branch or fork. The caudal stylets are a little longer than in the Greenland exainples, but this is probably due to the more mature development of the specimens. Length of male, 19"; length of claspers, 5""; length of 2d joint, 2™". Length of cercopoda or caudal appendages, 1.5"". Length of female, 18™"; length of ovisac, 5™. Although predisposed to think that Professor Verrill* had found good reasons for separating the Labrador from the Greenland individua!s under a distinct specific name, though I originally had examples of the Green- land B. paludosus from Dr. Liitken, of the Copenhagen Museum, for comparison, I have carefully re-examined them for any specific charac- ters that I might have overlooked. I see no differences in the append- ages, the 5th and 6th endites especially not differing in any essential point, as will be seen by the numerous figures on Plates IX and X, the apparent discrepancies in the drawings being due to different stages of preservation. There is a slight ditterence in the tips of the male claspers, which are a little blunter in the Labrador than in the Greenland examples, but this may be on account of the smaller size and less degree of maturity of the Greenland examples. I have not at hand the larger Greenland examples originally received from Greenland through Mr. Liitken. The Labrador examples were taken August 7, 1864, in a small pool of water in a depression in the rocks on a point of land projecting into the water at “Indian Tickle,” on the north side of Hamilton or Invuctoke Inlet, Northern Greenland ; and others were seen at Tub Island, on the south side of the entrance of the bay, August 10. We add the following account by Baird of what seems to be without much doubt B. paludosus, and which shows that it inhabits Arctic America in latitude 68° 15’ N., longitude 113° 50’, of Greenwich: ‘“‘Some fragments of a species of Branchipoda were brought by Sir John Richardson from Cape Krusenstern, in North America, collected there by Mr. John Rae in August, 1849, along with the Apus glacialis. They consist of portions of two males and two females. The male an- tenn are two-jointed ; the basal joint is thick, and has at its lower part, near its junction with the second, a row of small teeth; the second joint is cylindrical and pointed. The female horns or antenne are flat, ap- parently, and have a short hooked spine at the extremity. The caudal fins are rather long, and fringed with long cilia. In some respects this species resembles the figure of the Cancer paludosus of Miiller, but the fragments are too much decayed in the spirits to enable me further to describe it. It does not appear to have either antenniform appendages or any apparatus attached to the antenne of the male. Should these three species prove to be distinct they may form an- other genus of this family, characterized by the want of these append- ages and the toothed or serrated basal joint of the male cephalic horns.” Under the name of Branchipus (Branchinecta) arcticus, Mr. E. J. Miers notices this species in the Annals and Mag. Nat. Hist., ser. 4, vol. xx, p. 105, Pl. IV, fig. 1. His figure is a very indifferent one, and he erro- — neously represents the ovisac as double. Discovery Bay is in latitude 81° 41’ N., longitude 64° 45’ W. Wereproduce his description and remarks: **Coll. Hart: Discovery Bay, in a small fresh-water lake and in a stream under ice. Several specimens were collected, including males and females, of a species of Phyllopoda, which I refer to the B. arcticus of Verrill. Of these species I have only seen the descriptions in the jour- nals above quoted, not having been able to meet with Verrill’s full re- * Prof. Verrill writes me that he has since (Amer. Jour. Se.) decided that his B. groenlandica is identical with B. paludosa, 22 H 338 GEOLOGICAL SURVEY OF THE TERRITORIES. port on the American Phyllopoda in the volume for 1869 of the Ameri- ean Association for the Advancement of Sciences and Arts. These specimens possess the elongated claspers, with serrated basal joints, and elongated egg pouches of the species of Branchinecta, and are dis- tinguished from the Branchipus paludosus of Miiller, also from Green- land, (if his figure in the Zo6l. Danica, Pl. 48, be correct) by the much shorter lanceolate caudal appendages. In B. paludosa these are repre- sented as very slender, acuminate, and half as long as the abdomen. “These specimens differ shghtly from the descriptions of B. arcticus and groenlandicus, as will appear from the following description. If distinct (which may be possible, although I think it more probable that the three forms are varieties of one and the same species), the species may be designated B. Verrilli. The antenne are slender, linear, and nearly as long as the basal joint of the claspers. ‘The large prehensile ~ antenne, or ‘claspers,’ as they are called by Verrill, are nearly half as long as the body, two-jointed, the basal joint as long as the second, nearly straight, and of the same thickness throughout, with a not very prominent rounded lobe at the distal extremity on the inner side. This, and the distal half of the inner margin, armed with a series of ten or a dozen small teeth or spines. The second joint is smooth, slightly taper- ing to its distal extremity and concave on its inuer surface. The bran- chial feet are eleven in number, and the lobes on the inner margin are beautifully fringed with long, close, flexible hairs; the fifth and sixth pairs are the longest, and the others decrease regularly in size. The vesicular body is narrow, oblong-oval; the terminal lobe of the second joint is regularly oval in shape. The caudal appendages lanceolate, small; margins with slender sete, which become longer as they ap- proach the distal extremity. The specimens are smaller than that col- lected by Dr. Packard, averaging only 12 millimeters in length. ‘‘ Verrill’s specimens of this species were from Labrador, and if, as is thought possible both by Packard and Verrill, this species be not dis- tinct from the B. groenlandicus and B. coloradensis, it must have a very extended geographical range. Specimens of B. groenlandicus are men- tioned by Packard as having been obtained during the late American expedition of the Polaris at Polaris Bay, between latitudes 81° 20/ and 81° 50.” ‘ BRANCHINECTA COLORADENSIS Packard. Plate X, figs. 6,7. Branchinecta coloradensis Packard, U. 8. Geographical and Geol. Survey, Report for 1873, 621, fig. 12. 1074. Fic. 19.—Branchinecta coloradensis, male and female, with a view of front of the head of the male, showing the claspers; all enlarged. Emerton del. Body considerably larger than in B. paludosa; moderately stout; head rather large; ocellus larger than in B. paludosa, and the eyes also ! PACKARD.] PHYLLOPODS OF NORTH AMERICA. 339 ‘rather larger. The claspers of the male are large, thick, and long, ex-. tending to the base of the last pair of-feet. The basal joint is provided with stout prominent tubercles at the base; the joint itself is nearly one-fourth longer than the distance between the outstretched eyes. The second joint is one-half as thick as the first, and as long as the first be- yond the basal internal knobs; it is slightly bent near the base, the tips broad, rounded, and suddenly bent inwarils a little. The forks of the penis are long, slender, suddenly curving outwards, and nearly meeting at the tips over the median line of the body. The caudal appendages are rather long and slender, nearly twice as long as the terminal seg- ment, though shorter than in B. paludosa, and not slightly contracting near the base as in B. paludosa. Female larger and stouter than in B. paludosa; the ovisac very long and slender, reaching to a point beyond the middle of the penultimate abdominal segment, and with the lobes acutely pointed. The 2d antennz are much broader than in B. palu- dosa, being more triangular and coming more gradually to a mucronate point than in B. paludosa. In life this species is of different shades, from deep salmon or flesh color to pale whitish. Length of body of male, 18"™; length of male claspers, 7™"; of 2d joint, 3°"; of caudal appendages, 1”. Length of female, 17"; length of ovisac, 8™”. Described from several hundred specimens collected by myself from a small pond or pool forming the head of a brook above timber line and near the snow line, about 12,000 feet elevation, near the trail leading to the summit of Gray’s Peak; it is doubtful if this pond ever dries up, as I have seen it full in the summers (August) of 1875 and 1878. They were observed m great abundance August 21, associated with a species of Daphnia, and swam .as usual on their backs; a number were seen copulating. They thus live under almost exactly the same meteorologi- cal conditions as B. paludosa in Northern Labrador and Greenland, the temperature near the snow line in Colorado in August being about the same as that of Northern Labrador and Greenland in August. My first published brief description was drawn up from a female speci- men from a ‘‘pond on a mountain near Twin Lake Creek, Colorado, eleva- tion 12,500 feet” (Hayden’s Survey of Colorado, 1873, collected by Lieut. W. L. Carpenter, U.S. A.); also from about 100 males and females with eggs. Colorado, Dr. Viele (Museum Comp. Zoology, Cambridge, no date). From Mr. V. T. Chambers we have received the following note re- garding the occurrence of this form in Colorado: Beauchinecta Coloradensis occurs in countless thousands in a pond fed by melted snow on top of Weston’s Pass, altitude 11,676 feet elevation (Hayden), and a Caddis larva feeds voraciously upon it. BRANCHINECTA LINDAHLI 0. sp. Plate XI, figs. 1, 7. One male.—Body robust ; 2d antenne or claspers short and stout; 1st joint of the usual thickness and much as in BS. coloradensis, but much shorter, at least a third; 2d joint as long as the basal, curved, distinetly triquetal, with the angles prominent; much thicker than in B. colora- densis, rather blunter at the end than in B. coloradensis, and with the inner side of the tips larger and more turned in than in B. coloradensis, giving an entirely different appearance to the joint. Male genital or- gans much as in the Colorado species, but the caudal appendages some- what longer, otherwise of the same form. Twelve females.—Kyes rather large; 2d antenne slightly shorter, less blunt than in B&. coloradensis. Oviduct with the lower lip acutely pro- 340 GEOLOGICAL SURVEY OF THE TERRITORIES. duced. The caudal appendages are nearly twice as long as in B. colo- radensis. The eggs are nore numerous (about 50 contained in the ovisac) and much smaller than those of B. coloradensis, being about one-half as large. The feet are well developed; the 5th endite square and hol- lowed out a little on the outer edge; the 6th is long and more pointed than in the other species of Branchinecta; the gill is large, as is also the oval broad flabellum. : Male, length of body, 8™"; 2d antennz, 3™"; length of 2d joint, 13™"; caudal appendages, 1”. Female, length of body, 15"; ovisac, 4-5"; caudal appendages, ora This species differs remarkably, especially in the long caudal append- ages, and in the large pointed 6th endites of the feet. It may at once be distinguished from Branchinecta coloradensis by the shorter 2d antenne, the basal joint being one half shorter, and the 2d joint very short, while the inner projection or spur is much larger and more pointed than in B. coloradensis, and the caudal appendages are much larger, while the ovisac is much shorter than in that species. The eggs are of the same size as those of B. paludosus. The specimens occurred in a pool at Wallace, Kansas, in company with the other Phyllopods from that place. This species is named in honor of Prof. Joshua Lindahl, of Augustana College, Rock Island, Ill., who collected the specimens examined, with many other Phyllopods which he kindly lent me for study. Genus BRANCHIPUS Schaeffer (in part). Branchipus Schaeffer (in part), Elementa Entomologica, 1766 (type B. pisciformis=? B. stagnalis Ex. Verrill). lLatreille, Regne Animal; Leach. Milne-Edwards, Crustacés, iii, 364 (in part), 1840. Chirocephalus Dana (in part), non Bénédict-Prévost, 1803; Jurine, Thempson, Baird. Branchipus Verrill, Amer. Journ. Science, xviii, 250, Sept. 1869. Branchipes (and Hubranchipus) Verrill (in part), Proc. Amer. Assoc. Adv. S3., July, 1870. Body large and very stout; head large; male claspers elbowed, large and thick, complex, varying much in form; Ist joint very stout and thick, nearly straight, with a stout inward-pointing spine at base; 2d joint varying in form, usually simple and straight, chitinous, bent a little at the tip. Head of male with a pair of frontal appendages hang- ing down between the male claspers and varying much in form, being long, slender, filiform, and simple (in B. stagnalis), forming two broad, flat triangular lobes with crenulated edges (in B. vernalis), or very large and deeply and finely lobulated (B. grubei). The 11 pairs of feet are much as in Branchinecta, but usually the 5th endites are larger and the edge less square than in Branchinecta, and the 6th endites are larger and more pointed. The penis is large and broad, in B. stagnalis quite deeply cleft, or (B. vernalis) only slightly so, the cirrus long and slender. Caudal appendages long and slender, nearly twice as long as is usually the case in Branchinecta (B. lindahli excepted). Female with the body long, the head large, caudal appendages as in the male, the ovisac broad and short, bottle-shaped, the opening trans- verse, at the end of a short neck. The type of this genus is Branchipus stagnalis (Linn.) of Europe, and in this country it is represented by B. vernalis. As limited by Milne-Edwards, the genus was too comprehensive, be- ing composed of three generic forms, simce he included in it B. spinosus PACKARD.] PHYLLOPODS OF NORTH AMERICA. 7 341 and B. ferox, which, as we have previously explained, are true Branchi nectee, and also Chirocephalus diaphanus. In 1870 Verrill eliminated his Branchipus vernalis, described in 1869 under the name Hubranchipus vernalis, and also remarked that “this genus appears to include Bran- chipus spinosus Edwards, from a salt lake near Odessa, but the latter appears to have no tooth at the base of the second joint of the claspers.” Had Professor Verrill had specimens for examination he would un- doubtedly have seen that this species was a Branchinecta. I do not see good reasons for separating our common American spe- cies generically from the common European B. stagnalis and the less known more recently described species B. grubet. Comparing B. ver- nalis with 6. stagnalis, the frontal lobes of stagnalis are in position ho- mologous with the much more complicated ones of B. vernalis and the lobulated, highly complicated ones of B. grubet. In both species the 2d joint of the claspers is thick, in section triangular, but much slenderer than the very thick 1st or basal joint.* The ovisae and penis, as well as the caudal appendages and the gen- eral form of the body, are the same. B. grubei Dybowsky, which I have received from Breslau through Professor Siebold, is a genuine Branchi- pus; the large, deeply lobulated frontal appendages, a sexual character peculiar to the males, are only exaggerations of those of B. vernalis. It has similar stout claspers; the ovisac of the female differs from the two other species examined, in being a little longer and slender, but still it retains the short, broad, bottle-shaped form so characteristic of the genus, while the caudal stylets are the same. To this genus also undoubtedly belongs Fischer’s Branchipus biro- stratus (see Middendorf’s Reise, p. 152, Pl. VIL, figs. 12-16, from Char- kow, Russia). As regards the frontal appendages, this species is inter- mediate between B. vernalis and B. grubei, as those organs are short, triangular, but little longer than in B. vernalis, but deeply, acutely | lobed at: the end. The frontal appendages in this genus and in Chirocephalus are possi- bly the homologues of the knob-like projections near the base of the 2d antennez of Artemia and Branchinecta, but the frontal appendages are situated nearer the base of the 1st joint, and are more dorsal. On the outer side of each appendage there are transverse lines reaching to the edge between the tubercles, giving a segmented appearance to the outer half of the appendage. Under a Tolles’ + B eyepiece the tubercles are seen to be filled with nucleated oval cells like those scattered through the meshes of the fine muscles which ramify throughout the middle re- gion of the appendage. The cells are not nerve-cells, and I do not regard these organs as sensory, but probably auxiliary to the claspers, and possibly of use in holding the female. Synopsis of the species. Frontal appendages short, finely lobed; 2d joint long and POLEEC Ope eer eer ne ste te WE TE A Db Pe B. vernalis. Frontal appendages very long, with six long finger-like processes on each side; 2d joint of male clasper half as long as in B. vernalis, and square at tip......... BPP PSM Sra tieI ea ea che PLL Seth oe NTRS B. serratus. *Gerstaecker makes a singular blunder in copying Dybowski’s figure in Bronn’s Classen und Ordnungen der Thierreich, Bd. v, abd. 1, Taf. xxix, figs. 2,4, from Dy- bowski in Archiv. fiir Naturgeschichte xxvi, 1. The male and magnitied head of the male of Dranchinecta paludosa from Greenland, correctly figured by Dybowski as such, are by Gerstaecker in his explanation of Tat. xxix called the female of Branchipus grubei. 342 GEOLOGICAL SURVEY OF THE TERRITORIES. BRANCHIPUS VERNALIS Verrill. Plates XI, figs. 2-6; XXII, figs. 3-6. Branchipus stagnalis Gould, Invertebrata of Massachusetts, 339, 1841. Branchipus vernalis Verrill, Amer. Journ. Sc., XLVIIT, 251, Sept., 1869. Eubranchipus vernalis Verrill, Proc. Amer. Assoc. Adv. Se., July, 1870. Body stout, pale flesh-colored with reddish tints, head large; claspers with the basal joint very stout, slightly curved, nearly one-half as thick as long; retractile, drawing in ’ with it the base of the 2d joint; 2d joint chitinous, rigid, with a ‘long obtuse spur on the inner side at ‘the base, which is directed inwards at right angles; beyond this spur the joint in transverse section triangular, the edges very prominent; the inner edge of the joint is hollowed out at the base, while the extremity is bent outward somewhat like the foot of a sock before it is worn. The inter- antennal or frontal appendages are broad, triangular, flat (from above downward), nearly twice as long as broad, acutely pointed; with the edge finely serrated, the teeth, when highly magnified, being separate at base, and bottle-shaped, with one, and sometimes two, rarely three, ‘‘ necks” or ‘ points” (Pl. X XI, fig. 5, 5a). The external organ of re- production (penis) is stout, massive, not deeply cleft in the middle, while the cirrus (Pl. X XII, fig. 3, ¢) is minute, long, and filiform. The body of the female is as stout and of the same size as in the male; the ovisac is not so long as broad, pink, with a prominent, full ‘‘ neck,” with a transverse narrow opening "tor the exit of theeggs; the lower lip of the opening is smaller than the upper lip. Male.—Totallength of body, 23"; of 2dantenne, $="; 2d joint of same, 4.5°"; of penis, 3.5" ; caudal appendages, 4mm. Female.—Total length, 23™"; length of ovisac, 3-4™"; of caudal ap- pendages, 47”. This species ranges from Salem, Mass., through Rhode Island to New . Haven, and southward to Philadelphia (March 27, Mr. W. P. Seal) and westward to Southern Ohio (Wapakoneta, Ohio, Wm. Kayser), aud In- diana, (received from Irvington, Ind., Mr. O. P. Hay, Amer. Nat. 1882, 242). In Southern New England it is found from the last of November until the first week in May, but has not yet been found during the sum- mer from the middle of May until the middle of November, as will be seen by the following record of localities and dates of capture: Salem, Mass., April 19, 1859 (RB. H. Wheatland, Essex Institute); April 12, 1876, a few half-grown ones (Packard); Danvers, Mass., Nov. 25, 1578, Decem- ber and Jan. 10 (John Sears); Brookline, Mass., March 30, 1878 (ia Henshaw); Pawtucket, R. L, March 18, 1880 (H. H. Davison); New- port, hk. ie Feb 15, 1877 (Mr. Powell, Mus. Comp. Zool.); New Haven (Dana, Haton & Verrill); At Seekonk, Mass., they occurred abun- dantly May 2, in a large pond which completely dried up in summer (H. C. Bumpus) ; when it visited the pond in company with Mr. Bumpus, May 13, none were to be found. It seems from this quite evident that - the animal probably dies off at the approach of warm weather and does not reappear until after cool weather sets in late in the autumn, being represented in the summer by the eggs alone; and thus the appearance and disappearance of this Phyllopod is apparently determined mainly by the temperature. In life the body is of a pale flesh color, the tips of the penis deep red- dish-brown, from thence a narrow line widening to the posterior half of the abdomen. The white sete on the caudal appendages and the white tips of the endites contrast with the deep reddish-brown of the rest of PACKARD. ] PHYLLOPODS OF NORTH AMERICA. 343 the posterior half of the abdomen. The tips of the 5th endites are edged with reddish. Observed in very large specimens, from Dorchester, Mass. Jan. 4 to 9, 1882.* BRANCHIPUS SERRATUS (Forbes). Eubranchipus serratus Forbes, Bull. Illinois Mus. Nat. Hist. I. 13, Dee. 1876. This interesting species is of the size and general appearance of B. vernalis, but the frontal appendages are twice as large and long, reach- ing to the end of the first joint of the male claspers. They are broad and flat; on the middle of the inner and outer edge is an expansion from which arise six digitiform processes, those on the inner edge being shorter and smaller; the appendages each end in a rolled-up sleuder tip. Male claspers with the Ist joint short and thick; the 2d joint much shorter and thicker than in B. vernalis, being one-half as long, thicker in proportion, with the end squarely cut off, and triquetal seen from the end. At the base of the joint is a broad-based stout spur which points inwards. The caudal appendages are a little shorter and less coarsely setose along the edge than in B. vernalis. The genitals are aS in B. vernalis; the ovisac of the female is similar, the opening being the same, while the eggs are of the same size as in that species. Total length of male, 15-20"; length of claspers, 4""; length of 2 joint, 2"™; of caudal appendages in both sexes, 2.5-3™; total length of female, 20™°. ‘“Collected in temporary pools of water at Normal, Iinois, in April, 1876; about a fortnight afterwards it entirely disappeared.” “Another species [specimen] has been sent me by Professor Bundy, by whom it was taken in Wisconsin.” I am indebted to Prof. S. A. Forbes for a pair of type specimens of this interesting species, which bears a close resem- blance to, and thus represents in the United States, Branchipus grubet of Europe; it differs, however, from that species in the rather smaller frontal appendages, which are not so continuously and deeply fringed *The following observations by Dr. Gissler, made on the appearance of Branchipus vernalis and Chirocephalus holmani may prove of interest: BROOKLYN, November 14, 1881. I recorded the following in my memorandum last year: Ponds near Maspeth dried up in October, 1880, until October 30, filled up; heavy rain again November 5; heavy rain again and 68°F. on November 11; November 18, a thin coat of ice formed in the evening; November 19, little rain in afternoon, again cold in evening; November 20, cold; November 21, freezing; ditto November 22, 23, and 24, a little snow at 9 p. m.; 25th, snow, cold; 26th, very cold, and 27th and 28th, thawing after 10 a. m.; same day rain from 10 a. m. till 11 p. m.; 29th, clear and mild; 30th, frozen; December 1, rain; 2d, mild and clear; 3d, cool and clear; 4th, mild; 5th and 6th, warm; 7th, cold; 8th, 9th, 10th, and 11th, very cold; 12th, mild; 13th warmer, and 14th, ditto with rain; De- cember 15, 16, and 17, all ponds solidly frozen; 18th, thawed; 19th, frozen; ditto 20 and 21, with snow; frozen, 22, 23, and 24; thawing on 2oth; frozen, 26, 27, 28, and 29; December 30, 5° below zero; 31st, cold, frozen; ditto January 1, 2, 3, 4, and 5, 1831; milder and muddy on 6th, 7th, and 8th; colder on 9th, rain in the evening; ditto all day on 10th; 11th, went to Maspeth, ice 1 inch thick on isolated pond, water running into it from neighboring elevated fields, nothing found; 12th and i3th cold; warm rain in A. M. of 14th, cold after 3 p. m., went to Maspeth and obtained one larva, the smallest I ever saw, from pale race; 15th, 17°F. at 9 a. m.; cold 16th, ob- tained 3 red Lubranchipus larvee a few days old; 16th, cold; 17th mild; ditto 18, 19, and 20, eight inches ice at Maspeth; 21st, warm rain; 22d, snowed over night, cold; 23d, cool; 24th, 25th, and 26th, cold; 27th, 28th, 29th, 30th, and 3lst, very cold; a larger larva was found February 10, age about 5 days; heavy rains February 18 and 19; March 3, obtained from Maspeth 4 larve 51™™ long, red Hubranchipus, ice 3 inches; March 6, obtained 17 larve of the red Lubranchipus between 3-5™™ long, no pale ones seen; March 11, obtained 40 or 42 half-grown red Hubranchipus; March 23, a great number of adult Chirocephalus found near Glendale. C. F. GISSLER. 344 GEOLOGICAL SURVEY OF THE TERRITORIES. with the digitate processes as in the European form. Its oceurrence, however, in this country and its being an intermediate form between B. vernalis and B. grube: shows that the genus Hubranchipus is not suffi- ciently distinet to be regarded as a valid genus. As our description is brief and gives only the salient points observed in alcoholic specimens, we reproduce Mr. Forbes’s original descriptions, drawn up from living examples: “An important character, constant in the large number of both sexes which I have examined, is found in the abdominal segments, which are narrowed in front, with rounded anterior angles, while the posterior angles are produced backward, giving a decidedly serrate appearance to the abdominal margin. The last two abdominal segments are closely united and broader than the preceding. “The antenne extend a little beyond the eyes, and terminate in a cluster of about five slender olfactory clubs. The frontal appendages of the male are considerably longer than the claspers, to the front inner base of which they are attached, the line of attachment being parallel to the length of the basal joint. Their form is irregularly oval, the inner edge being regularly convex on its distal three-fourths, and the outer sinuate-convex on basal two-thirds, and slightly concave on ter- minal third. Both margins are pectinate, except near base, with thick blunt teeth, which are ‘longest on, the basal half of the outer margin, where they are as long as the undivided part of the appendage is wide. At the middle of this : margin the teeth become suddenly shorter. On the inner margin they are longest near the middle, regularly lessening towards each end. The under (posterior) surface of the appendage, as well as the teeth, is set with short spines, each springing from an in- flated base. The claspers of the male are shorter and stouter than in LE. vernalis. The basal joint is soft and inflated and bears a corneous rounded tubercle at its inner base (wanting in vernalis). The second joint is stout and regularly incurved, strongly angulated at its base in front where it is received into the first joint. A long strong tooth, about half as long as the joint, extends backward and a little inward from near its base. The rounded tip of this tooth is thickly set with minute, low, circular elevations, each with a central depression, within which is a disk-like elevation, the whole having the appearance of a minute sucking disk. The tip of the clasper is expanded and flattened within so that the inner (anterior) part has a spatulate form, while the opposite surface rises into a thick prominent ridge, giving to a trans- verse section of the tip the form of the letter T. The anal appendages are linear-lanceolate, as long as the last four segments of the abdomen, and plumosely haired to the base. The ovisac of the female is as broad as long, three lobed behind, with the middle lobe the largest. “Length of a full grown male, including anal stylets, 20""; width, 6™™; across eyes, 4°"; clasper, 4.5""; frontal appendage, 5™™ by 3™”. The largest females were a little more slender than the males.” Genus STREPTOCEPHALUS Baird. Plate XII; figs. 1-7. Streptocephalus Baird, Annals and Mag. Nat. Hist. 2d Ser. XIV, 219. 1854. Heterobranchipus Verrill, Amer. Journ. Se. xlviii, p. 250. 186 9. _ Streptocephalus Verrill, Proc. Amer. Assoc. Adv. Se. July, 1870. Body rather slender, much more so than in Branchipus. 2d anten- ne of male 3-jointed, remarkably long and large, tortuous and twisted, PACKARD. ] PHYLLOPODS OF NORTH AMERICA. 345 the basal joint stout, armed externally at the end with a very long, slender spur, about as long as the joint itself; the 2d joint thick, very long and bent upward and inward; near the end on the inside is a row of small papilla; at the extremity it enlarges into a short, thick hand- like portion, the 3d joint, which divides into two long unequally forked chitinous appendages. 2d antennee of the female as usual, broad and suddenly mucronate at tip. Eleven pairs of feet; much as in Branchi- necta and Branchipus: the first endite as usual, but the fringe is rather long, as also that of the other endites; the 5th endite square, the outer edge hollowed out, the spines on the lower edge few and un- usually blunt; the 6th endites more acute than in Branchipus; the flabellum large and rounded, fuller than in Branchipus ; the gills rather large. The penis consists of two separate very long curved filiform processes. Ovisac of the female long and slender, much as in Brancht- necta. Caudal appendages longer and broader than in Branchipus. This genus differs from Branchipus in the want of frontal appendages, and may be easily identified by the long 3-jointed twisted and elbowed claspers, and by the two long slender filamental processes forming the male genital armature. Judging by the form of the 2d antenne, par- ticularly the 1st joint, and by the absence of any frontal appendages, and especially the form of the ovisac, Streptocephalus appears to be a modified Branchinecta, and to have been differentiated from that genus rather than from Branchipus; in fact we may, I think, regard Branchi- necta as the more generalized, ancestral type of the family. Synopsis of the species. Male claspers larger and slenderer at tip than in S. similis ...S. teranus. Male claspers shorter than in S. tevwanus......-..---- see. eee: S. sealir. - Male claspers shorter and broader at base than in S. tew- CRUST, ise he) Beals WA Si Na Us gta kA Shy Sha Ye SP aes Met ae S. floridanus. STREPTOCEPHALUS TEXANUS Packard. Plate XII, figs. 1-7. Streptocephalus texanus Pack., Amer. Journ. Se. August, 1871. Streptocephalus watsonii Packard, Hayden’s Annual Report of the U. 8. Geol. & Geogr. Survey of the Territories for 1873, p. 622, Pl. IV, fig. 13. Male.—Front of the head with a small median lobe which projects downward between the bases of the second antenne, and is flattened, Fic. 20. Streptocephalus texanus, enlarged. broad at the end, but not lobed, there being but a very faint median sinus. The subconical upper surface of the head bearing the oblong ocellus near the front edge is truncated-conical, being a little longer than broad. 1st antenne long and slender, twice as long as the eyestalk, 346 GEOLOGICAL SURVEY OF THE TERRITORIES. 2-jointed, 2d joint about two-thirds longer than the 1st, tapering towards the end; basal joint curved a little at the base. 2d antenne or clasp- ers large and tortuous; the basal joint extends outward and downward ; the 2d joint extends backward parallel to the body, and is bent at ri ioht angles to itself, and the 2: is directed forwards and inwards, the ends nearly meeting over the median line of the body; 3d joint short, swol- len, and subdividing into three branches, the longest of which reaches in its natural position to the 8th segment behind the Ist antennary seg- ment. An antenniform appendage springs from the end of the basal joint and reaches to the end of the 5th ring behind the eyes; it is slen- der, flattened, and much as described in S. similis Baird. At the end on the outside of the 2:1 joint is an acute, short, flat, conical appendage. Of the two terminal large appendages, the longer and slenderer one is sinuate and sends off a slender spur from the base, reaching nearly to the bend in the appendage, where there is a slight projection, beyond which it is long and slender, flattened, cylindrical. The other append- age is irregularly flattened, very sinuate, and about two-thirds as long as the other. Near the base on the outer edge are two flat lamellate teeth, the inner much the smaller and slenderer; the outer broad and suddenly ending in a finger-like point, the appendage ending abruptly in an acute point. For want of material it is difficult to draw up a good comparative description of the appendages of this species as compared with A. floridanus and A. sealii. By reference to the figures on Plate XII a good idea of the form of the appendages and their endites and exites can be obtained; but which characters are generic and which specific would be difficult to say. The 1st endite is broad and large. with long, fine, hair-like sete; in the 8th pair the base of the edge of the 5th endite has six stout, truncated, short * spines (see Pl. XII, fig. 51°). The gills are oval, lanceolate in form; the flabellum rather broad and well rounded on the outer edge, which is serrate, the teeth giving rise to small, fine sete. The male reproductive. organs arise ‘from the Sth segment counting forward from the telson, or the 15th from the head, and are slender, simple, unarmed, cy lindtical, of the same thickness ‘throughout, with the end blunt, and are curved around so as to touch at their origin. Telson very short; caudal appendages but slightly separated at base, Jong and rather stout, gradually tapering to the end and well fringed on both edges. Length of the whole animal, 16.2"; length of longer appendage of 2d antenne, 4.2"; length of caudal ‘sty lets, 3.2"; length of penis, bo ae Female. —Differs from the malein the 2d antennex, which scarcely reach beyond the 1st antennze, and which are flat, conical, ending in a finger- shaped point. Ovisae attached to the 13th and 14th segments behind the head; it reaches backwards to the segment in front of the telson, forming a long cylindrical sac ending in two valves, the upper one tri- angular, hollowed beneath, the under one short, forming the end of the ovisac. The external opening of the oviducts are situated on the basal segment of the abdomen. The eggs are a little the larger at the end of the ovisae. The caudal appendages are rather shorter and considerably stouter than in the male. Total length, 14"; of caudal appendages, 3"; of ovisac, 5™. This description is mainly based on the few examples received from Waco, Tex., through Mr. G. W. Belfrage, who found it in 1871, and again February li, 1872, with Limnetis and Estheria. Afterwards a lar ge num- ber, mostly immature, were eure from Dr. Watson, at Ellis, Kans., and PACKARD. ] PHYLLOPODS OF NORTH AMERICA. 347 these were supposed to represent a different species and described in the Bulletin of Hayden’s U.S. Geological Survey of the Territories in 1877. Since then I have received a number of specimens from Wallace, Kans., through Professor Lindahl, some of which. were of the same size and state of preservation as the Texan specimens, and which showed no specific differences, and finally, on carefully examining and drawing the feet of specimens from the two States, I found that they could not be separated specifically. I append the description of the Kansas specimens from Hayden’s Bulletin, which may show bow the individuals vary, especially in the male claspers: ‘¢ Male.—The claspers (2d antennz) are much longer than in S. texanus, reaching, when extended, to the middle of the body, while in S. texanus they only reach a third of the length of the body. The median lobe of the head, which is very large and long in S. teranus, reaching nearly as far as the insertion of the basal filamentary appendage of the third joint of the claspers, is, in S. watsoni, not half as large. The two basal joints of the claspers are twice as long and much slenderer than in VS. texanus ; the third joint is nearly as long, while the branches and spines of the 4th joint, though of the same number, are much longer and slen- derer. Of the longer branch the supplementary spine is much longer, and without the small inner spine, while the main branch beyond is bent at right angles, the elbow being much bent, the inside, however, regu- larly curved. At the base of the broader and shorter branch are four unequal teeth; one attached to the third joint, the other to the fourth, the two terminal ones very unequal, and the fourth square and three times as large as the third, while the corresponding tooth in S. texanus is long and narrow, and smaller than the one behind it. The genital appendages are long and slender, much as in S. tevanus, being as long as the three segments following the one to which they are inserted. The caudal ap- pendages are much shorter and broader than in S. texanus, each blade being broader, and tapering regularly from base to tip, not contracted in the middle, nor curved, as in the male of S. texanus ; on the other hand, they are of much the same form as in those of the female S. texa- NUS. ** Female.—Very closely allied to the female S. texanus, though as a rule somewhat smaller, the eyes being decidedly smaller. ‘The second an- tenne are a little, sometimes much, longer in proportion, and are mu- cronate, as in the other species. The ovisacs are as in WN. fexanus, but the eggs are much smaller in proportion. The caudal appendages do not differ materially from those of the males, nor from those of the females of S. texanus. ‘Length of males, 16™™; females, 12-18™™. About fifty of each sex examined, although several hundred were casually looked over, with- . out finding any that approached WN. tevanus any nearer than has been indicated. “ Hillis, Kans., in pools on the prairie, June 28, 29, September 27, and October 10-22, Dr. L. Watson. ) we) ica] a tl ics es) [="I>) a ta S) i) Bs) H Se Q °.4 = A aA Ay Seoul iS}S) =| a Quaternary : Mertiany i. -cc--5- 5 5- Mesozoic) -sesss--41- Carboniferous .-...- Mevonian assess see SWirrmbin 5625 sebsaece Banrentian 0-22. - = Protonauplius. Protocyclus. Simultaneously with the appearance of the larva-like Agnostus, and the more highly organized Paradoxides, &c., we find in the Lingula flags the remains of a species of Phyllocarida, the Hymenocaris vermicauda. Mr. J. W. Salter, who was the first author to draw attention to the close relation of the fossil-genera Hymenocaris, Ceratiocaris, Peltocaris, Dictyocaris, &c., to Nebalia, has given us a series of sketches showing graphically the geological succession of this group and the Estheriadie. Hymenocaris, which Salter regards as “the more generalized” type, lived during the primordial period; Peltocaris and Discinocaris (Wood- ward) characterize the Lower Silurian period; Ceratiocaris the upper; Dyctyocaris the Upper Silurian and lowest Devonian; Dithyrocaris and Argus the Carboniferous. No Mesozoic member of the family has yet been discovered, but as there are several species of Nebalia now living in our seas, it is reasonable to suppose that the type has existed in an unbroken succession from primordial times until now. The Pa- leozoic species were gigantic in size, some being about a foot or more (the carapace of Dithyrocaris pholadomya Salter being seven inches long) in length, while our recent Nebalia is less than an inch in length. The Potsdam sandstone also contains the remains of a third grand division of Entomostraca, the Ostracoda; remains of Leperditia having been found in Canada, as well as the Lower Silurian of Europe. No fossil Copepoda have yet been discovered, but we should scarcely wonder at this, owing to their soft bodies. Gerstaecker (Bronn’s 362 GEOLOGICAL SURVEY OF THE TERRITORIES. “Classen und Ordnungen der Thierreichs” ) suggests that the Lernzans might have infested Paleozoic fish, and on general grounds we should think that they probably extended as far back as the primordial zone, inasmuch as highly developed Trilobites and Ostracodes appear there. Ano'ther argument is the interesting discovery made in 1865, by Mr. Woodward, of the Cirripede Turrilepas Wrightit from the Wenlock limestone and Dudley shale of the Upper Silurian formation. Previous to this, according to Woodward, ‘the oldest known Cirripede was the Pollicipes rheticus from the Rheetic beds of Somersetshire”; while tiie type is not uncommon in the Cretaceous, and has flourished from that period to the present. Of the Merostomata the oldest group is the Eurypterida, the Xipho- sura not dating beyond the Lower Carboniferous. The Eurypterids have not been found below the Upper Silurian (Lower Helderberg in America), and the aberrant forms Hemiaspis, Bunoddes, Pseudoniscus, and Exapinurus are Upper Silurian forms. Among the Xiphosura, Cyclus, the lowest form, is found in the Carboniferous, and ranges, ac- cording to Woodward, as far up as the Permian. In the same period occur Bellinurus, Prestwichia, and Euproéps, being in this country found in the lower part of the true Coal-measures, and associated in the same beds with Ceratiocaris, Hurypterus (Anthraconectes and certain Isopoda and Macrurous Decapoda (Anthrapalemon). The genus Limu- lus first appears in the Jurassic, and the species differ but shghtly from those now living. The more typical Phyllopeda made their appearance during the Triassic period. The lowest group, however, the Estheriade, appeared during the Devonian, a species referred to Estheria being found in that formation in Kurope. The Cladocera are not known to have existed previous to the Tertiary period, and it was not until recently (1862) that Von Hayden discovered the ephippium of a Daphnia in the Rheinish brown coal (Gerstaecker, in Bronn’s Klassen und Ordnungen, We.), said by Lyell to be of Eocene age. It should be noticed, however, that the fossil be- longs next to Sida, the most highly organized genus of the group, and as it is not unlikely that such pelagic forms as Nvadne may have existed in the Mesozoic seas, if not earlier, [ have ventured to run the point of the wedge into the Carboniferous period. The Apodidez date back to the early part of the Mesozoic, a Triassic species of Apus having been found in Europe, according to Mr. Salter. HI.—GHOGRAPHICAL DISTRIBUTION. (With a map.) The materials for the thorough study of the geographical distribution of the Phyllopod Crustacea of North America, as indeed of any other of the continents, perhaps not excepting Huropeo- Asia, are quite scanty. The exceptional habits of the members of this suborder, their usual rarity or periodical occurrence, and their very local distribution, have caused them to escape the observation of most collectors, and to be found more by accident than as the result of well-matured plans of search. The salient points in the distribution over the globe of the Phyllopods are as follows; although the conclusions here presented are, of course, provisional, and much - yet remains to be discovered as to the distribu- tion of these interesting forms. It will be seen by reference to the lists presented in the following pages that a large proportion of our North America Phyllopoda, includ- ing nearly all the species of Hstheria, are restricted to the elevated dry central zodgeographical province of the United States, and adjacent Co PACKARD.] GEOGRAPHICAL DISTRIBUTION OF PHYLLOPODA. 36: portions of Arctic America, and of Northern Mexico, a region exposed to great summer heats, winter cold, to long droughts, sudden rainbursts, and other meteorological extremes. And jit is interesting to notice that the larger proportion of the Old-world forms are likewise restricted to Eastern and Southern Europe, to the Mediterranean region, and to Central and Northern Asia, 7. e, to Mr. Sclater’s “ Palie-arctic Region.” The Western European species are few in number, as in the Eastern United States. In Africa the Phyllopods are restricted to the northern portions of the continent, which are more or less elevated, dry, and arid, as Algeria, Egypt, and Abyssinia, or to the Cape of Good Hope (Capeland), while but a few, and those species of Hstheria, have been brought from the “Oriental Region” in Asia, and few from the Aithi- opian Region” in Africa. Apus himalayanus, described by us from the Himalaya Mountains, is evidently a member of the Central Asiatic or Manchurian province, and not of the Indian region, while A. dukianus is reported from Afghanistan. Of purely tropical forms there are two species of Apus, one living in St. Domingo, another in the island of St. Vincent, while a species of Eulimnadia exists in St. Domingo, and a species of Hstheria flourishes in Cuba. The Mexican forms are plateau species, while none have yet been described from Central America. Two species of Hstheriahave been described from South America. The map accompanying this memoirl represents the principal faunal divisions of North America, with the isothermal lines of 32°, 40°, 60°, and 72°, The American continent is divided into— . The Arctic Realm and its Alpine outliers. . Boreal province and its Alleghanian outliers. . The Atlantic or Eastern province . The Central province. : . The Western or Californian province. . The Antillean region. There are no species from the Central American province. > OU 09 bo THE AMERICAN ARCTIC PROVINCE. This is a more or less natural subdivision of the Arctic or Circumpolar Realm, which includes the coast of Labrador, the northern shores of Hudson’s Bay, and the Arctic coast of North America, north of the sothermal of 32° around to Bering’s Strait and Greenland. We reject the term “ Nearctic” proposed by Mr. P. L. Sclater, and adopted by Mr. A. R. Wallace, for America north of Central America, for the reason that it seems to us an unnatural and artificial term. The fauna is essentially American north temperate, while the Arctic regions of America and Europe-Asia form a realm by itself, of much less impor- tance, it is true, than the north temperate realm (American and Kuropeo- Asiatic regions), when we consider the land plants and animals, but of nearly as much importance as regards marine life. To apply the term Nearctic to so vast a region as the American involves the idea that the region covers an area essentially arctic in its features. Itis to be hoped that the term will not be adopted by American writers, as it is not by German avd French writers, and we heartily indorse Mr. J. A. Allen’s protest against the use of the term by American writers on this subject. The cireumpolar or Arctic realm is a realm by itself, limited by the low degree of temperature and mainly bounded by the isothermal of 329, and the adoption of this term will conduce, it appears to us, to 364 GEOLOGICAL SURVEY OF THE TERRITORIES. clearer and more concise ideas of the geographical distribution of life on our continent.* The following two species of Phyllopods characterize this realm: Lepidurus glacialis, Arctic America, Lapland, Nova Zembla, Spitzbergen, Beeren Island; and Branchinecta paludosa. Neither of these are confined. to the ‘American continent (being found at Cape Krusenstein) and Green- land, as they occur in Arctic Kurope and Asia. These two species oc- cur not only in Greenland and Arctic America, but also in Swedish Lapland at an elevation of 2,000 feet; Branchinecta paludosa occurs in Finmark near the North Cape and in Russian Lapland, and Middendorf found it (var. middendorfianus) in Asiatic Siberia. THE ATLANTIC OR EASTERN PROVINCE. This region includes the area bounded on the north by the isothermal of 40°, including the northern shore of the Saint Lawrence west of Que- bec, the Great Lake region, except the northern shores of Lake Superior, and the United States east of the ninety-seventh meridian.. The following species inhabit this province: Tamnetis gouldii. Hstheria mexicana. (Limnadella coriacea. ) Hulimnadia agassizit. Limnadia americana. Branchipus vernalis. Streptocephalus sealia. serratus. floridanus. Chirocephalus holmant. THE CENTRAL PROVINCE. This province lies between the Atlantic and the Californian, extend- ing northward into British America to the limits of trees near latitude 55°; and southward along the Mexican plateau as indicated on the map. The Rocky Mountains oppese no continuous barrier to the distribution of the species; and it includes the southern extremity of the Californian peninsula. We reproduce from the American Naturalist for August, 1878, the leading characteristics of this Central province. The first attempt to divide the United States as a whole into zoélog- ical provinces was in 1859, by Dr. Le Conte, in his “‘ Coleoptera of Kansas and Eastern New Mexico (Smithsonian Contributions, 1859).” He di- vided the Coleopterous fauna of the United States into three great zodlog- ical districts, distinguished each by numerous peculiar genera vand species, which, with but few exceptions, do not extend into the contiguous dis- tricts. He named them the Eastern, Central, and Western divisions ; *In our ‘‘Observations on the Glacial Phenomena of Labrador and Maine,” etc., Mem. Bost. Soc. Nat. Hist., 1856, p. 254, we thus referred to this fauna, speaking espe- cially of the marine animals: “The arctic or circumpolar fauna is restricted to a district north of the yearly iso- thermal line of 32°, which thus includes the Arctic American archipelago, Northern Greenland, Spitzbergen, Nova Zembla, and the coast of Siberia. Thisisatrue circum- polar fauna, and can scarcely be said to be Asiatic, European, or American, though members of the group extend in diminished numbers and size down on the Asiatic coast to Japan, as we are informed by Dr. W. Stimpson, and by P. P. Carpenter in the Report of the British Association for 1856; on the European coast as far as the Mediterranean Sea, and on the eastern American coast as far as New Jersey, where the polar currents give, at great depths, the necessary amount of cold for their existence.” Compare also our monograph of Geometrid Moths, or Phalenide, of the United States, pp. 567, 586, 1876. Our Classification of the American fauna is adopted with slight “modifications from Mr. J. A. Allen’s writings on the Mammals and Winter Birds of Florida, ete., Bull. Mus. Comp. Zodl. ii, 3, 1871, Bull. Hayden’s U. S. Geol. Survey, 1878, p. 529. packarp.} GEOGRAPHICAL DISTRIBUTION OF PHYLLOPODA. 365 so that to him is due the credit of first distinguishing the Central prov- ince. | In 1866, Professor Baird,! from a study of the avifauna of the United States, concluded that ‘the ornithological provinces of North America consist of two great divisions of nearly equal size in the United States, meeting in the vicinity of the one hundredth meridian, the western half divisible again into two, more closely related to each other than to the eastern, though each has special characters. These three sections form three great provinces to be known as the western, middle, and eastern ; or those of the Pacific slope; of the great basin, the Rocky Mountains and the adjacent plains; and of the fertile plains and region generally, east of the Missouri.” _ In 1871, Mr. J. A. Allen? divided the avifauna of the United States into two provinces, the eastern and western, the latter embracing the Pacific coast. Mr. Allen afterwards adopted Professor Baird’s division into three provinces. (The geographical distribution of the mammalia, ete. Bulletin of Hayden’s U. 8. Geographical and Geological Survey of the Territories, May 3, 1878.) In 1873,? Mr. W. G. Binney published a map of the distribution of our land shells, dividing the molluscan fauna into the Hastern, Central, and Pacific provinces. In 1875, Prof. E. D. Cope, in his check-list of North American Batra- chia and Reptilia,* divided the Nearctic realm of Sclater into the Aus: troriparian, Eastern, Central, Pacific, Sonoran, and Lower Californian regions. He remarks that “the Pacific region is nearly related to the Central, and, as it consists of only the narrow district west of the Sierra Nevada, might be regarded as a subdivision of it. It, however, lacks the mammalian genera Bos and Antilocapra, and possesses certain pecu- liar genera of birds, as Geococcyx, Chamea, and Oreortyx. . . . There are some genera of reptiles, e. g. Charina, related to the Boas, Lodia, Aniella, Gerrhonotus, and Xantusia, which do not occur in the central subregion. There are three characteristic genera of Batrachia, all Salamanders, viz: Anaides, Batrachoseps, and Dicamptodon; while the eastern genera Plethodon and Diemyctylus reappear after skipping the entire central district.” Cope adds that “‘the fresh-water fish fauna is much like that of the central district in being poor in types.” Cope’s Sonoran region is evidently a northward extension of the Central Ameri- can fauna, which sends its outliers into Southern Arizona, Utah, and New Mexico, and is not to be taken into account in discussing the faunal provinces of the United States alone. In 1876, Wallace, in his “Geographical Distribution of Animals,” di- vided the Nearctic region into four subregions, viz: the Californian, Central or Rocky Mountain, Alleghanian, and Canadian. His Central subregion extended to lat. 25° N. It will be seen from this review that by general consent the fauna of the Pacific slope is on the whole regarded as belonging to a separate province from that of the Rocky Mountain plateau, whether we regard the mammals, birds, reptiles, amphibians, Coleoptera, or land shells. Botanically, as observed by those who have traveled across the plains to California, the flora of the great plains is quite different from that of the Eastern States, and the Pacific flora is as distinct from the central flora. This has been clearly shown by Sir J. D. Hooker and Prof. Asa American Journal of Science and Arts, January and March, 1866. ? Bulletin of the Museum of Comp. Zoology, April, 1871. a Catalogue of the Terrestrial Molluses of North America. Bull. Mus, Comp. Zool., 1873. 4Bulletin U. §. Nat. Mus., Washington, 1875. 366 GEOLOGICAL SURVEY OF THE TERRITORIES. Gray in their preliminary notices of the results of their botanical re- searches in connection with Dr. Hayden’s U.S. Geological Survey of the Territories. In traveling in the summer of 1877, in pursuance of the work of the _ United States Entomological Commission, I passed rapidly over a large area of the Central province lying north ot the fortieth parallel, including Colorado, Wyoming, Northern Utah, Western Idaho, Central and North- ern Montana, and was thus enabled to observe in a superficial way the gen- eral features of the flora and fauna nearly up to the British line. I was im- pressed with the resemblance of Central and Northern Montana to North- ern Utah, the insect-fauna being apparently nearly identical. Doubtless this insect-fauna extends northwards into the Upper Saskatchewan val- ley as far as the southern limit of trees, there being much less intermix- ture with Canadian forms than might be expected. Then crossing the Sierra Nevada, and going overland to Oregon, I was able to trace the gradual passage of the Californian insect fauna into the Oregonian, with some Canadian forms; and by passing up the Columbia River to Wal- lula, here as well as at Reno in Nevada, to perceive the great differences between the fauna of the Pacific slope and that of the plains and deserts of the Central province. In briefly reviewing the different orders of insects, other than Cole- optera, which have been so fully elaborated by Dr. Le Conte, and cer- tain groups of Crustacea, we will begin with the Hymenoptera, and point out a few characteristics distinguishing the Central from the Pacific provinces. In 1865 and 1866 a large number of Coloradian fos- sorial Hymenoptera passed under the writer’s hands, Mr. Cresson hav- ing previously described from this material a large number of Colo- radian Hymenoptera of all families. The richness of the hymenopterous fauna of Colorado struck me, and I was impressed with its distinctness from that of the Eastern States. I have seen few of these from Calli- fornia. Among the family of ants (Formicidae), there was one form characteristic of the plains which does not occur on the Pacific slope. This is the Pogonomyrmex occidentalis (Cress.). I have seen its large hills at Brookville, Kans., and observed them in Colorado and Utah, and in Reno, at the base of the Sierra Nevada, but not west of that point. It ranges, according to Mayer, south into New Mexico, and San Luis Valley, Colorado. Its nest, forming large elevations in_cleared spaces sometimes six or eight feet in diameter, is one of the character- istic sights on the plains. Among the Lepidoptera, family Bombycidw, there are several forms peculiar ‘to the central district, notably the genus Dirphia (Coloradia), Huleucopheus, Gloveria (Mesistesoma), Hemileuca, Juno, and Hera, and Platysamia gloveriit. The family is feebly represented in the Central province, but richly so by numerous species on the Pacific slope, which do not appear east of the Sierra Nevada. The Phalenide, or geometric moths, are richly developed in the Pacifie province, and but poorly in the Central province, owing to the absence of deciduous trees; of those found in the latter some occur west of the Sierra Nevada, and some are peculiar to the plains and Rocky Mountains. Of the Orthoptera there is a large number of species peculiar to the plains which I did not observe in the Pacific States; of these, Calop- tenus spretus is thoroughly characteristic of the Central province. It does not occur in the Pacific and only breeds temporarily in the Eastern provinee, and its natural limits define well those of the province itself. It ranges up to latitude 53° N. on the North Saskatchewan and south Ce ee mA SP ase = PACKARD.] GEOGRAPHICAL DISTRIBUTION OF PHYLLOPODA. 367 to Southern Utah and Colorado. The exact limits of its distribution are given in the First Annual Report of the United States Entomologi- eal Commission. While we are still quite ignorant of the distribution of insect life be- tween the hundredth meridian and the Pacific Ocean, there seems good reason, from what little we do know, and from the great differences in the dora, and the soil and climate, especially the rainfall east and west of the Sierra Nevada, to regarél this lofty range as the general point of separation defining two grand zoological provinces. Many groups of insects abounding west of the mountains do not occur east, except in isolated cases. Of a number of Myriopods found on the Pacific coast none occur east, and so of the Arachnida so far as known, and Dr. Thorell, who has worked up some of the spiders of Colorado, was struck by the general similarity of some forms to those occurring in the plateau of Northeastern Asia. Among the insects there are a few Pacific forms which closely resemble European species, and which are not represented east of the Sierra Nevada. It should be borne in mind, however, that the Sierra Nevada does not present an absolute barrier, as a considerable number of species occur on each side of if, and it is well known that the Rocky Mountains are but a slight barrier to the distribution of the animals on either side, the fauna of Colorado, Northern Utah, Wyoming, Montana, and Idaho being quite homogene- ous, and the fauna of these Territories the same on each side of the high mountain ranges traversing them. Among the fresh-water Crustacea the Astaci of the Pacific slope, as is well known, belong to the European genus Astacus, those east of the Sierra Nevada to the genus Cambarus, which is so richly developed in the eastern provinces, especially in the Mississippi Valley. The distribution of the fresh-water Piyllopoda is of peculiar interest. The family Apodide is restricted to the Central province; none are found in the Mississippi Valley, and none in California. Of the four species of Apus all inhabit the Central province; Apus wqualis lives on the plains of the Rocky Mountains, and also at Matamoras, in Mexico. Jt is a curious fact that Apus lucasanus Pack. not only oceurs at Cape Saint Lucas, Lower California, but is also an abundant species at Ellis, Kansas. This is a parallel case to the presence of certain birds at Cape Saint Lucas which, as observed by Professor Baird, belong to the Central rather than to the Pacific province. Of the genus Lepidurus there are two forms (L. couesiti and L. bilobatus) characterizing the plains. JZ. couesvi occurs in Northern Montana and in Utah, and is allied to the re- cently described Lepidurus macrourus from Archangel, Russia, accord- ing to Lilljeborg. The eastern limits of the Central province extend to near the 97th meridianin Kansas and Nebraska, according to the writer’s observations. The following species inhabit this province : Limnetis mucronata. Lepidurus bilobatus. brevifrons. Apus newberryi. gracilicornis. cequalis. Estheria compleximanus lucasanus. mexicana. longicaudatus. belfraget. Branchinecta coloradensis. Morseéi. lindahli. Eulimnadia texana. Streptocephalus texanus. Lepidurus couesii. Thamnocephatus platyurus. 368 GEOLOGICAL SURVEY OF THE TERRITORIES. THE CALIFORNIAN OR PACIFIC PROVINCE. But one species, Hstheria californica, (unless H. newcombiu be regarded as distinct) inhabits this area, which is separated by the Cascade Mount- ains and the Sierra Nevada from the Central province, and extends from 52° north southward to San Diego. No species is as yet known from Central America; and the two Mexican forms occur in elevated regions in Northern Mexico, and are not peculiar to Mexico, being characteristic of the Central province of the United States. : THE ANTILLEAN PROVINCE. The species inhabiting the West Indies are comprised in the following brief list : Hstheria jonesiv. Apus guldingit. Hulimnadia antillarum. Artemia guildingit. Apus domingensis. Streptocephalus similis. SPECIES COMMON TO THE ATLANTIC AND CENTRAL PROVINCES. Estheria mexicana ranges from Ohio to Lake Winnepeg, northward, and westward to Western Colorado, and into Northern Mexico. Artemia gracilis ranges from Salem, Mass.,to Mono Lake, in California, but the life-conditions of this brine-inhabiting genus are so exceptional that we have not mentioned it in the foregoing lists. Our only truly Al- pine form is Branchinecta coloradensis, found at an elevation of 12,000 feet in Colorado. SPECIES INHABITING SOUTH AMERICA (Brazilian Region). Estheria brasiliensis Baird. Brazil. Estheria dallasii Baird? Brazil. SPECIES INHABITING THE EUROPZO-ASIATIC REGION. a.— The European Province. 1. Western Europe. Limnetis brachyurus. Germany. Estheria cycladoides. Toulouse. Limnadia hermanni. France and Germany. gigas. Central and Northern Europe. tetracera. Germany. Branchipus stagnalis.* England and Central Europe. grubet. Central Europe. Artemia salina. England and Europe. Chirocephalus diaphanus. England, France, Switzerland. Lepidurus productus. England and Central-Europe. Apus cancriformis. Central Hurope. . grubet. Germany. lubbockit. Germany. _ * Branchipus lacune Guérin, Baird, Grube; and B. braueri Frauenfeld, are regarded by Lilljeborg (Nov. Acta Upsala (3), ix, A, p. 3) as synonyms of B. stagnalis. : “a ( PACKARD.] GEOGRAPHICAL DISTRIBUTION OF PIITYLLOPODA. 369 2. Eastern Europe (Russia, &c.). Limnetis brachyura. Limnadia tetracera. Charkow. Estheria pestensis. Pesth. Branchinecta feroz. Odessa. claviger Nordmann. Odessa. Branchipus birostratus. Charkow. brauert Frauenfeld. Parndorper (oe, Chirocephalus carnuntanus Brauer. Be Streptocephalus torvicornis. Warsaw. Artemia salina, vars. milhauseni. arietina. koppeniana. b. The Mediterranean Province (including Northern Africa). Estheria dahalacensis. Abyssinia. donaciformis. Korkofan. gubernator. Cairo. hierosolymitana. Jerusalem. gihoni. Jerusalem. lofti. Bagdad. 2 cycladoides. Algeria. melitensis Baird. taicinensis. Italy (Lombardy). Apus numidicus. Algeria. cancriformis. Italy, Algeria, and Constantinople. Branchipus eximius. Jerusalem. Chirocephalus recticornis Brauer. Tunis. rubricaudatus Kosseir. oudneyt. FKezzan. Branchinecta ferus Brauer. Jerusalem. Artemia sp. Egypt. Chirocephalus bairdti Brauer. Jerusalem. ce. Siberian. LTimnetis brachyura. Archangel. Polyartemia forcipata. Northern Sweden, Lapland, Taimyr, and Si- beria. Branchinecta paludosa (Middendorfianus). Siberia and Lapland. Chirocephalus claviger (Fischer). Taimyr, Siberia. Lepidurus macrourus Lilljeborg. Archangel. d. Manchurian. Apus dukti Day. Afghanistan. Apus himalayanus. (North Ibdia.) Apus numidicus Dauria. Baikal Sea. Apus sp.* * Apus sp. in Tibetan Salt Lakes. Schlagintweit, Reisen in Hochasien ii, 218, 872. 24 H 370 GEOLOGICAL SURVEY OF THE TERRITORIES. SPECIES INHABITING THE INDO-AFRICAN REALM. a. African Region. (Central Africa, White Nile; South Africa, Cape ot Good Hope.) Limnetis wahlbergi. Port Natal. Limnadia africana Brauer. White Nile. Estheria rubidgei. Cape of Good Hope. macgilivrayi. Cape of Good Hope. australis. Caffer-land. Apus dispar Brauer. White Nile. sudanicus Brauer. Chartum. Branchipus abiadi Brauer. White Nile. Streptocephalus cafer. Port Natal. vitreus Brauer. White Nile. proboscidens Frauenfeld. Chartum. b. Indian Region. Estheria compressa. India. hislopi. India. polita. India. boysti. India. similis. India. Branchipus dichotomus. India. Apus granarius. Peking. SPECIES INHABITING THE AUSTRALIAN REALM. Limnetis maclayana. Australia. Limnadia stanleyana. Australia. Apus viridis. Tasmania. angasit. Australia. Apus sp. New Zealand. Lepidurus kirki Thompson. New Zealand. compressus Thompson. New Zealand. From these data it appears that but a single genus is peculiar to North America, 7. e., Thamnocephalus; while Polyartemia is peculiar to the Europxo-Asiatic Region; all the other genera occur in nearly all of the continental masses of the globe, though no Branchipodide occur in Australia, and no Limnadia has yet been found in Asia. This cos- mopolitan distribution of the Phyllopoda (the Branchipodide, the high- est family, being excépted) poimts towards the high antiquity of this group of fresh-water crustacea. The distribution through ZONES across continents, noticed by Gerstaecker, appears not to be exceptional to that of other classes. We have noticed it in Geometrid moths, and also in mammals, the central portion of Asia repeating the characteris- tics of Central North America. IV.—_MORPHOLOGY AND ANATOMY. A transverse section of the anterior part of the body of any genus of Phyllopods will convey an excellent idea of the leading features in their organization, especially those by which they differ from the members of other Crustacean orders. The leading topographical features in the body, particularly of Arthropods, are the form of the elemental seg- ments with their appendages, and the relations of the principal anat- omical systems to the body walls. General relations of the systems of organs to the body-walls.—We will first - look at sections of representatives of the three families of Phyllopods ; 4.e., an Hstheria (Plate XXIV, figs. 9,10), Apus, Plate XX XII, fig. 2 (see also fig. 25 in text), and a Branchiopod, such as Thamnocephalus (Plate PACKARD.] MORPHOLOGY OF PHYLLOPODA. - ol XIV, fig.4). The body-walls are rather thick and the muscles are well de- veloped, particularly the dorsal extensor muscles, and the motor or exten- sor muscles of the limbs, which Hee arise in part from the dorsal re- os gion, and in part from the sides and sternal region. The body cavityisrathersmall. Theheart J /------(----. is large, either cylindrical as in Estheria, or fattened asin Tham- nocephalus. The digestive tract is large, capacious, and the cav- ity of the head is mainly filled with the two liver masses; the brain being remarkably small, while the nervous cord, especially the brain and succeeding gan- glia, are remarkably small and weak, compared with other Crus- tacea, either the malacostracous or the entomostracous orders ; this peculiarity is well brought Fic. 25.—Section of Apus. ht, heart; int, intestine; out in the transverse sections, fife fnathovase! gill and 7b, labellum, represeating tho thoracic ganglia, particularly in Hstheria (Plate XXIV, figs. 9 n, 9), is noteworthy. The apparent bulk of the body is largely due to the large size and nature of the leaf like or foliaceous appendages, with their broad attachments ; the latter peculiarity is characteristic of the Branch- iopods in general and the Phyllopods especially, and is quite different from the definite, small coxal articulations of the legs of Malacostraca or Copepoda. The ovaries or testes, according to the sex, form a large lobulated mass extending along each side of the digestive canal, as far forward as the base of the head. Their relations in Apus are seen in Plate XXXII, fig. 2, and in Thamnocephalus in Plate XIV, fig. 4. Nomenclature of the body-regions and appendages.—As the terms “ head,” “thorax,” and “abdomen” are more or less inexact when used for Arthro- poda as compared with the worms and molluscs, as well as vertebrates, there should be suitable designations for these regions. In 1869, in our Guide to the Study of Insects, we proposed the term arthromere for the segment or ring forming the primary element in the composition of the body of any jointed or articulated animal. The terms “zodnule,” ‘ zodnite,” “ zonite,” and “ somite,” have been used by various authors, but these terms have been used rather indiscriminately, and we therefore suggested the term arthromere tor the body segments of articulated animals (worms and arthropoda). While the term ‘‘somite” or ‘‘zonite” may be properly applied to the rings of worms and other ani- mals as the Chitous, we would suggest that the term arthromere be re- stricted to the segments, or body-elements of Arthropoda, For the three primary regions of the head the only scientific terms as yet in use are those proposed by Prof. J.O. Westwood in Bate and Westwood’s History of British Sessile-eyed Crustacea (vol. 1, p. 3). These are cephalon tor the head, pereion for the thorax, and pleon for the abdomen; while the thoracic feet are termed pereiopoda anu the abdom- inal legs pleopoda ; the three terminal pairs being called wropoda. As the names applied to the thorax and abdomen have no especial morphological significance, the Greek zepatov, simply meaning ulterior, and zicuy, more, we would suggest that the head of Arthropoda be termed the Cephalosome, the cephalic segments cephalomeres, and the cephali¢ © ©)hint aa 372 GEOLOGICAL SURVEY OF THE TERRITORIES. appendages in general protopoda, the term “‘cephalopoda” being other- wise in use. The thorax of insects and of most of the crustacea might be designated the Banosome (favo, to walk, locomotion), and the tho- racic appendages Benopoda, the segments being called bcanomeres ; while Urosome might be applied to the abdomen, the abdominal segments being called uromeres. Westwood’s term uropoda might be extended so as to include all the abdominal appendages. The term gonopoda we have suggested for the external organs of the Decapods concerned in reproduction, which are simply modified uropoda. The long, slender, antenna-like anal appendages of the cockroach, mantis, Wc., correspond. ing to the anal cerci of Acrydii, may be designated as cercopoda, and this term might be applied to the terminal pair of uropoda of the Phyl- lopods, 2. ¢., the jointed, slender, spinulose appendages of Apodide, or the unjointed appendages of the Branchipodide. The segments of the body.—The Phyllopoda are exceptional to other Crustacea in having an indefinite number of segments composing the body, and in having in one family (Apodide) more than one pair of ap- pendages to an arthromere. While the normal number in the Decapoda 3s 20, in the Phyllopods it varies from 14 in Limnetis to47in Apus. The following table shows the number in different genera of American aD cies : >) ta) =| n 2B < 3 3a ay 2 o 5 SS ea} o 7 a 0) 2a =e) 2 & = a zl D Q aa I I a ir > | 5 s .S 5 ZI A rs) Q & A $ S g & 2 oO ° : @sophageal ring; ng, abdominal ganglia. gus, the position of the stomach under the eyes so far in front in the head, the simple archi-cerebrum, the gen- eral form of the heart, and the gnathobases near the mouth are addi- tional points of resemblance. 412 GEOLOGICAL SURVEY OF THE TERRITORIES. In his little tract on Worms and Crustacea,! Professor Hyatt refers to the simple eyes of Limulus, as if they were the primitive eyes, re- tained from larval life. The structure of the two simple eyes of Limulus — appears to be in some important respects quite different from that of Apus, Estheria, and other Phyllopods, in which there is a circle of cones, while in Limulus there is a single large corneal lens on the same plan as the facets of the composed eye of the same animal. If, how- ever, these simple eyes, be regarded as survivors of the primitive larval eye, it would suggest that Limulus and all Merostomata which have similar eyes, have like the Neocarida, descended from a Nauplius an- cestor; although the development of Limulus polyphemus has been shown to be an abbreviated one, the young hatching in the form of the adult. The presence of the single eyes would of course be an argu- ment for its Crustacean affinities ; while on the other hand the posses- sion of compound eyes is a still more important Crustacean character. Another point of interest is the mode of moulting in Limulus as com- pared with Apus. From our childhood we have found the cast shells of Limulus, with the carapace split around the edge of the doablure, and we have a partially moulted specimen in alcohol. We have not seen a cast skin of Apus, but on asking Dr. Gissler, who has raised the young Apus from the egg, as to the mode of exuviation in this Crus- tacean, he writes me as follows: “I am certain that the larve of Apus (from skins examined) split across or just in front of the eyes, and with two or three jerks the animal rids itself of the underlying skin.” It would appear then that Apus, which is shaped in front so much like Limulus moults in a nearly similar manner. In a general way we accept the homologies pointed out by Professor Lankester between the Phyllopodous leg and the maxillze and maxilli- pedes of the cray-fish, but think that he, in common with Professor Huxley, pushes the homologies too far when he proceeds (on p. 365) to compare minutely the first leg of Apus with the third maxillipedes of Astacus. We do not, as we have stated on p. 391, regard the axis of Apus as truly jointed, and he stretches his homologies entirely too far when he attempts to homologize the first and second endites of Apus with the coxopodite of Astacus; and the third and fourth exites of Apus with the basipodite of Astacus. We would suggest that here, as among the orders of Arachnida, or Hexapoda, or Myriopoda, if we do not stop ata certain point, we are led into erroneous and misleading attempts at too close homologies. We should, it seems to us, bear in mind the fact that there are ordinal and class homologies; or, in other words, there are different degrees of blood relationship, 2. e., different and more or less parallel branches of the Crustacean genealogical tree. The Decapods did not descend directly from the Phyllopods, but by a longer line, independent on the one hand from the Phyllocaridous an- cestral line, and on the other from the Branchiopodous stem or branch. But a comparison between the Phyllopedous leg and Decapod maxilliz and maxillipedes shows that the Decapod exopodite is but a modified endopodital lobe, and is not homologous with the exites of the Phyl- lopods, the latter corresponding to the epipodite (or gills and flabellum, of the Decapods. We have seen that in all Phyllopods the gill and fla- bellum are differentiated parts of the epipodal portion of the leg (epipo- dite). Huxley’s view, that the base of the corm or “ protopodite” of the first thoracic foot is the endopodite, and the endites are merely second- 1Boston Society of Natural History. Guides for Science Teaching, No. VII, Worms and Crustacea. By Alpheus Hyatt, Boston, 1882. Fie 8 ee Be i SS ee A a ee a es PACKARD. ] HOMOLOGIES OF THE CRUSTACEAN LIMB. 4i3 ary processes, is apparently not correct. We regard the Phyllopodous limb as not differentiated into an axially-jointed portion, but that it is ' divided into a dorsal and ventral portion, the outer side of the limb being epipodal and the inner side endopodal, the endites of Lankester being processes of the endopodal portion. | Returning now to the general homologies of the Crustacean limb, in the light of Professor Lankester’s suggestions as to the nomenclature of the limbs of Apus, and from our knowledge of the limbs of Crustacea from the Copepoda and Ostracoda upward, and more especially the Cladocera, Phyllopoda, and Phyllocarida compared with the Decapoda (the Tetradecapoda being considered as a side branch of the Malacos- traca and not affecting the general homologies here given), we would suggest the following views: Looking at the generalized legs of the Cladocera as exemplified in Moina (fig. 28, third pair), we see that there is no specialized,axis or stem, and that the limb may be divided into an outer, partly dorsal or respiratory epipodal moiety (the dotted portion in the figures), and an inner, ventral locomotive moiety, which may be called the endopodal portion of the limb. Now, if we look at the figures in the plates we shall see that the larger part of the epipodal or respiratory portion of the limb is thrown up over the back, as seen in the side view of Limnetis, Estheria, Limnadia (Plates I, I1I—V), or in the sections of Hstheria (Plate XXIV), Apus (Plate XXXII, fig 2), or Thamnocephalus (Plate XIV, fig. 4). This relation is also seen in the lobster or cray-fish upon removing the side of the cara- pace; the branchiz and flabellum are thrown up dorsally, while the loco- motive portions of the limb hang down or are usually directed forward. The importance of the epipodal or branchial portions of the limb has been underestimated by writers on the homologies of the Crustacea, because they have viewed the subject from the standpoint of the Decapodous structure, where the epipodites are comparatively unimportant. But in the order Branchiopoda these parts are often quite as well developed as the endopodal, and are not only respiratory, but, as in the large fla- bellum of the Phyllopods, are largely locomotive, while in the Limna- diade and Apodide they are variously modified to carry the eggs. The epipodal portion is differentiated into the flabellum and branchia or gill, the simple gill of the Phyllopods being the homologue of the highly differentiated complex decapod gill; and the fan-like flabellum of Apus, for example, is the homologue of the scaptognathite of the Decapoda. The gill and flabellum might be properly called branchites, but we have adopted Lankester’s term, exites, for these parts. The endopodal or locomotive portion of the limb of the Phylopod is differentiated into six lobes or endites (Lankester); there being no parts corresponding to the stem or protopodite (the coxopodite and basipodite together) of Decapods. These are to be found only in the Decapoda. In Apus there is a slight approach to the Decapodous protopodite, but we differ from Huxley or Lankester in regarding the base of the apodid leg as truly axial and jointed, as the supposed joints are shifting and with incomplete articulations. Lankester considers ‘‘that the endopo- dite of the Astacus maxillipede is the homologue of the endite 5 of the Apus limb; its exopodite is homologous with endite 6 of the Apus limb, and its epipodite is homologous with the flabellum of the Apus limb.” (Quart. Jour. Micr. Sc., 1881, p. 365.) AIA GEOLOGICAL SURVEY OF THE TERRITORIES. The nomenclature and synonymy of the parts of the Crustacean limb: in general may, then, be tabulated as follows: Epipodite, flabellum, scaphognathite, gill-scraper, a ‘an. (In Limnadia Epipodal portion of limb - + upper or dorsal (br) part (oviger) ana lower (br). ranchia, eee in Phyllopod thoracic legs. 3 endites in 2d maxilla of Astacus and Sergestes. 4 endites in Ist maxillipede of Astacus and Sergestes. 2endites (5th and 6th endopodite and exopodite) in 3d mazxilli- pede of Astacus and Homarus. 1 endite ? (=5thPhyllopod endite?) in thoracic leg of Homarus and Astacus arising from a2-jointed axis or protopodite (consisting of coxopodite and basipodite), to which are appended (a) epipodite and branchia. (5 dactylopodite. (b) (endless) the leg in Decapoda with 5 . é Dee i joints | 2 meropodite. (1 ischiopodite. The carapace.—This is seen, when we study the development of the Phyllopods, to originate in the Nauplius as the undifferentiated covering or tergal portions of the first and second and mandibular segments of the Nauplius, which become enlarged during the successive moults of the animal until, as in Hstheria or Limnadia', it may cover the entire body. In adult life it becomes bivalvular and is attached to the body by the adductor muscle, which is situated in the mandibular segment, the prz-oral part of the head in the Limnadiade and Apodide being more or less differentiated from the carapace proper. As long ago pointed out by Professor Dana, the carapace of the De- capoda (the lobster for example) is a development of the tergal portion of the second antennal and mandibular segments. The development of Penewus and Huphausia from the nauplius to the adult confirms the view that the carapace is originally the antennal and mandibular tergites which form a single carapace and finally covers the cephalothorax of Decapoda. That no part of the carapace represents the thorax is seen in the zoéal carapace which covers the front part of the body OEE EG the thoracic segments are developed. Endopodal portion of limb, with— l HOMOLOGY OF THE EYES. When we consider the nature of the compound eye of the Cladocera and Phyllopoda and study the mode of development of the cornea from epidermal cells, we see that the eye-stalk of the Branchipod eye is simply an unjointed protuberance of the first antennal segment, and can in no way be regarded as the homologue of a jointed appendage. Moreover, the embryology of these Crustacea shows that the compound eyes are developed upon the tergal part of the first segment of the head, and that there are no traces of a pre-antennal segment. In the Decapoda our unpublished observations on various zoe (Lupa, Palemon and Tozeuma carolinensis), as well as the data given by those who have written on the embryology and metamorphosis of Decapods, all show that the faceted stalked eyes of Decapods should not be re- garded as homologues of the legs, although eminent authorities, such as Huxley, Claus and others, regard them as being the morphological equivalent of the succeeding jointed members. In Tetradecapods the compound eyes are invariably sessile. In the Merostomata, Limulus, as 1In Limnadia, as shown by Lereboullet (see Fig. 43), and in Estheria, as stated by Claus, the carapace valves apparently arise from a post-mandibular segment, but this is exceptional among the Phyllopods. . | | oa : PACKARD. ] DEVELOPMENT OF PHYLLOPODS. Al15. well as its fossil allies, and the Eurypterida, the compound eyes are sessile and situated on the third segment of the head, and, as we have endeav- ored to show in our essay on the development of Limulus polyphemus,} the stalked eyes of Decapods do not represent a pair of appendages. V.—THE DEVELOPMENT, METAMORPHOSES, AND GENE- ALOGY OF PHYLLOPODS. I.—THE NAUPLIUS FORM IN THE PHYLLOPODS. As introductory to the notes furnished by Dr. Gissler on the develop- ment of Apus and Streptocephalus, we will preface his remarks with some account of the early phases of different Phyllopods, beginning with Limnetis, as worked out by Grube.” The young of this genus is a Nauplius of peculiar form, with three pairs of appendages, a very large carapace which covers the entire body, and the edges of which are serrated. The carapace is larger than in any other Phyllopod larva known, and there are two large lateral hornlike projections from each side of the head in front of the first pair of ap- pendages. The labrum is not especially developed, while in the other genera it forms a characteristic feature of Phyllopod nauplii. LTimnetis gould has a nauplius of the same general shape as the European species, a8 we have received specimens of a similar carapace from Hanover, N. H. | A quite full account of the development of Limnadia hermanni has been given by Le- reboullet. Fig. 42 represents the freshly-hatched Nauplius, which is of very primitive form. The first pair of antenne are in the Nau- plius wanting, not budding out until near adult life. The labrum (Ib) Fic. 42.—Nauplius of Limnadia hermanni. ant2, second antenna; md, man- is enormous and dible; %, labrum. Much enlarged. After Lereboullet. very long. The carapace arises in this genus, as also in Estheria, from a point in the head just behind the mandibular segment. Fig. 43 rep- resents the larva before the first antenne have begun to grow out. The ocellus is still large and performs its functions, while the abdomen ends in a pairof uropoda. Thedevelopment of Hstheria, as given in a fragmentary way by Joly, shows that the Nauplius differs mainly from that of Limnadia in the labrum being three-toothed at the end. Fig. 44 represents the freshly hatched larva of Apus cancriformis ; the usual three pairs of nauplius-appendages representing the first and second antennz, and the mandibles of the adult are present; while the ovate body is segmented behind the mandibular segment. The first larval stage of Lepidurus, as worked out by Brauer (Tigs. 45, 46), israther different from that of Apus. The limbs are slenderer, and a rudimentary carapace arises on the antennal segments, while the body behind is not segmented. !Memoirs Boston Soc. Nat. Hist., 1872, Vol. 1, pp. 174, 175. ?Bemerkungen tiber die Phyllopoden. A16 GEOLOGICAL SURVEY OF THE TERRITORIES. Plate XXII, fig. 1, provisionally represents the freshly hatched larva a | i Fic. 43.—Advanced larva of Limnadia hermanni, lettering as in fig. of Artemia gracilis, which we observed at Great Salt Lake, Utah, the drawing having been made from an al- coholic specimen. On comparing it with Claus’ figure of the freshly hatched larva or Nauplius of the European Branchipus stagnalis (Fig. 47) the first antenné are seen to be much shorter; the second pair with much shorter and smaller sete; while the mandibles are nearly destitute of setae. Moreover the body is segmented be- hind the mandibles. _ Our Salt Lake Ar- temia differs from the figures of the Euro- pean Artemia salina in the shorter first anten- ne; in the shorter and 42. sh, carapace valves; int, intestine; J, liver, mnch enlarged. After smaller setze of the Lereboullet. second antenne. But a single larva was, however, observed, and our figure is, though a camera drawing, subject to future correction. Fie. 44.—Nauplius. freshly hatched, of Apus cancrijormis. s, segments behind the mandib- ae segment; J, liver; e, simple eye. After aus. Fig. 45.—Nauplius of Lepidurus much enlarged. Aiter Brauer. THE GENEALOGY OF THE PHYLLOPODA. In considering the question of the genealogy of the Phyllopods, we have two sets of considerations to guide us. First the embryology, anatomy, affinities, and systematic position of the group, and second a eS PACKARD.] GENEALOGY OF CRUSTACEA. AIT their paleontological history, the latter being an important check upon any errors arising in the former. It has seemed to us the more natural view that the systematic posi- tion and relations of the Phyllopods, as compared “i with the Cladocera, is that : the Phyllopods are simply a highly developed and ex- tremely specialized branch of a Cladocerous stem ; that the Cladocera are a step higher than the Ostracoda, which connect the Bran- {i chiopoda with the Copepoda. |\\\\ There is a tolerably com. /\\\\\ plete ascending series of | forms, beginning with the . ° Fic. 47.—Nauplius of Branchi- Fig. 46.— Advanced Copepoda and culminating pus stagnalis. After Claus. larva of Lepidurus en- in the Phyllopods. Here larged. After Brauer. we should stop, and in endeavoring to account for the origin of the De- capoda, we do not see what facts there are to sustain the view that the highly specialized Decapoda, much less the Tetradecapoda, originated from the Phyllopods or forms like them. The more natural view 1s that the Malacostraca originated by a direct line of ancestral forms, resem- bling the zoéa, protozoéa, &c., beginning with a Nauplius condition; the development of Penewus and Leucifer giving us data for such a by- pothesis. Hence the Phyllopods and Decapods, for example, for a time proba- bly followed the same developmental path or rather parallel paths. The Phyllopods, culminating in the highly specialized peculiar type of Apo- dide and especially the Branchipodide, were the flowering out or con- sumation of, so to speak, the Branchipodous branch of the Neocaridan crustacean tree. On the other hand the Decapods, beginning with the Nauplius form, perhaps more rapidly and by an accelerated course of development comparatively late in paleontological history, assumed the primitive Decapodous characteristics perhaps before the Phyllopodous type had been perfected, but in the Tertiary Period culminated in a great profusion and luxuriance of forms, remarkable for the number of species and variety of shapes of macrourous and especially brachyurous types. The paleontological history of the Neocarida, as we have endeavored to show by the diagram on p. 361, shows that the shrimps existed dur- ing the Devonian,! that the crabs were already in existence during the Carboniferous Period, before the Apodidw and Branchipodide had, judging by their fossil remains, appeared; while the Limnadiada, gen- uine Phyllopods, appeared before any Decapods in the Devonian, the Ostracodes being abundant in the Lower Silurian strata. It seems tous therefore most probable from a geological standpoint that the Decapods could not have originated from the Phyllopods, as the two types were developed during the Palzeozoic era. That the Phyllocarida were developed independently either of the - Phyllopods or of the Decapods seems probable from the fact that the Phyllocaridan type became established as early as the Lower Silurian. We shall see that the Phyllocarida are not related to the zoéa of Dec- apods, and that the Decapods probably did not originate from them. ' Palwopalemon newberryii has been described by Whitfield from the Devonian of Ohio. 27 418 GEOLOGICAL SURVEY OF THE TERRITORIES. Hence the three orders of Branchiopoda, the Phyllocarida, and the Dee- apoda (with the Tetradecapoda) must, it appears to us, have indepen- dently of each other originated from some Laurentian Nauplius-like form. The views of Claus and some important criticisms upon them are given at length by Mr. Balfour in his valuable Comparative Embryol- ogy, while we would observe that neither Claus, Dohrn, nor Balfour appear to refer to the paleontological history of the Crustacea. Professor Claus, in his suggestive work on the genealogy of Crustacea, according to Balfour, claims that the later Nauplius stages of the dif- ferent Hntomostracan groups and the Malacostraca (Peneus larva) ex- hibit undoubted Phylopod affinities. He therefore postulates the earlier existence of a Protophyllopod form, from which he believes all the Crus- tacean groups to have diverged. This ancestral form, Balfour thinks, had three anterior pairs of appendages similar to those of existing Nauplii. It may have had a segmented body behind the third pair of appendages provided with simple biramous appendages. =>——== a basal hook bris- tle, first pl ain Fic. 56.—Sete of first maxilla of Eubranchipus. then ciliate (Fig.55 a) and then split. Second bristle-hook appears (Fig. 5d d) to be triangular or rounded exteriorly, and two-edged and ciliate Fic. 57.—Anterior antenna of pale Eubranchipus mounted in gly- cerine osmic acid prep. From a specimen with three branchipeds budded, 1st of the latter with a single claw. interiorly. The terminal outer branch of the second an- tenna has fifteen long bristles and a terminal shorter one; the inner or posterior branch has three long and one short bristle. This branch is three-jointed; terminal branch is subjointed. First maxilla of adult Eubranchipus is plain, and has thirty-one long, flat, acinaciform bristles or teeth, equally long (Fig. 56.) The second maxilla is composed of a narrow, small, basal piece, with two strong, thick spines, each finely ciliate. 430 GEOLOGICAL SURVEY OF THE TERRITORIES. Mandibulary palpus is four-jointed, bearing seven ciliate bristles, the two basal and the three terminal ones being nearly straight (more so the former); the two middie bristles have a stout base, — and are curved inwardly (Fig. 55 ¢). ch---\ The first (anterior) (Fig. 57) and second antenne have their basal half, in very young forms, at least, / peculiarly ciliate. This is mentioned also by F. Span- genberg, but not figured. Second antenne.—At the time of sexual differentia- tion the greater part of the bristles and the inner Fig. 58.—a. Same larva branch drop, the basal piece sprouts a few single cilize ei tet or ihe etiee with (NOt in groups), and from the under side at its base asingle claw) : Lowerpart the future first clasper-hook begins to bud, which of abdomen with a chitin- c 5 ous bacillus, ch., entering then becomes corrugate at its tip. An exuberant ae eee Elser a cell—complex in the basal piece, formation of trans- retreated through the ef- verse and longitudinal muscles, subdivision of the fect of osc terminal piece of the antenna near its base, and bud- ding of a small roundish protuberance at the inner side of the middle piece takes place, and the male clasper is nearly developed. If a female specimen, the en- tire antenna re- eee mains but with Fas on he eee muscular differ- entiation; and at its inner b ase, on Fig. 59.—Seta of first maxilla of Streptocephalus texanus. a broad frontal protuberance, a number of hyaline ciliz appear. Some- what later the form of the female clasper slightly changes into one peculiar to this genus (Fig. 61), which is very vari- able in form. jy, At the time when in the male clasper the first / hook is budding, the frontal tentacles are already present, but owing to their tendency to coil ven- trally and their small size I did not succeed in closely following their mode of origin (Fig. 60 B). In its early stage the margin is entire, with a con- tinuous row of large marginal cells; plasmatie contents in general intermingled with oil globu- les, and longitudinal muscles transversely striate. I think at a later time the latter will branch lat- erally, since the developed tentacle shows also transverse muscles. The peculiar mammiform excrescences along the margin are attained after several moults. . r Larvee with three branchipeds budded, the first of which, with a single claw, show the develop- ment of the post-abdominal furca, as illustrated by Fig. 58. I am of the opinion that the narrow piece running along the end of the body is a sup- Fic. 60.—Right male clasper POTt for the embryonic fwrea, and is not a musele, Eubranchipus, from life. A, but a chitinous stick or bacillus, which, after one Pant, dd antennas D lonsitnds OF more moults (Fig. 63) is pushed out, and its eae ae Brea integument becomes ciliated. But the latter, after ¥, future inner angle wherefrom More moults, does not become the permanent Wino Homerton Wall ines Jurca, as we should expect, for it is cast off with _ the other integument, and the typical development of the furca begins (Fig. 62). PACKARD.] DEVELOPMENT OF BRANCHIPODIDZA. A431 No internal chitinous support is found until in the adult state, when we again meet with a flat chitinous plate, confined to the furca alone. It is -—-—-samaey Fig. 62. Fic. 61.—Female claspers; 6 more peculiar to the pale race. an interesting phenomenon to see that the red normal Lubranchipus has a white and the ale prace a red furca. The transparent, greenish, Chirocephalus holmani and the whitish Streptocephalus texanus have also a red furca. The red Hubrancht- pus occurs in brownish, clear water, the others in tur- bid, milky water. It may be an assistance in copu- lation, i. e., to make the individuals more visible, or conspicuous. Spangenberg (in op. cit. page 10) makes it more than plausible that the first (anterior) antenne PS tnt N Fic. 63.—Last few seg- Fic. 64.—Hubranchipus, red 9 larva, 13™™ long; ments of an Eubranchipus sides of head fimbriate above. From lite. Giss- laryaof13™™length. Cam- ler del. ‘lucida drawing fr Toanted osmic acid pre, Of Branchipus are homologues of the leg, and I ven- a iar en aie DGS to compare the frontal tentacles in a similar integument (by the osmic manner. The following points support this theory : acid); i antcstine; 1) First, they are lateral appendages; second, their marginal, appendages, more developed exteriorly, closely agree with the embryonic development of the branchipeds, from a single mammiform process up to two and three of the latter. The frontal appendages are different in nearly every species of branchio- pod crustaceans; they are sometimes on the basal portions of the clasp- ers in the adult, or they are reduced to minute papillae. Dybowsky? calls them basal appendages, referring to the base of claspers, while Grube calls them more properly frontal appendages ; Fischer calls them cephalic tentacles (Middendorf’s Reisen nach Sibirien, Band IL); Verrill calls them lanceolate, ligulate, fleshy processes. \Archiy. fiir Naturgeschichte, 1860, Vols. 1 and 2, 26th Jahrgang: Beitrag zur Phyl- lopoden. Fauna der Umgebung Berlins nebst Kurzen Bemerkungen tiber Cancer pal- udosus Miiller von B. von Dybowsky, M. D., page 195, Taf. X. AS? GEOLOGICAL SURVEY OF THE TERRITORIES. VII.—THE ORDER PHYLLOCARIDA AND ITS SYSTEMATIC POSITION. Having studied the Phyllopoda, we may now discuss the relationships of Nebalia and the group which it represents. History of the Phyllocarida.—The genus Nebalia was first established by Leach! in his Zoological Miscellany, vol. 1, p. 99,1814. Nebalia geoffroyt Kdwards, was described and the external appendages figured by Milne-Edwards in the Annales des Sciences Naturelles,: tome 13, p. 297, 1828, and in the 2d series, tome 3, p. 309. Our Nebalia bipes was originally described under the name of Cancer bipes by Otho Fabricius in his Fauna Groenlandica, 1780. In his Histoire naturelle des Crustacés (1840) Milne-Edwards places Nebalia in the family Apusidze among the Phyllopoda; at the same time he remarks: ‘‘Les Nébalies sont de petits crustacés tres-curieux qui, a raison de leurs yeux pédonculés et de leur carapace, se rapprochent des Podophthalmes, mais qui ne possedent par de branchées proprement dites, et respirent a Vaide des membres thoraciques devenus mem- braneux et foliacés. Elles semblent, a plusieurs égards, établir le pas- sage entre les Mysis et les Apus.” ! In 1850 Baird, in his British Entomostraca, founded the family Nebaliade, regarding Nebalia as a Phyllopod. In 1853, in his great work on Crustacea, Prof. J. D. Dana gave the name Nebaliade to the family, with a diagnosis. He placed the group in his tribe Artemioidea in the Legio Phyllopoda. Nebalia remained, by the general consent of carcinologists, in the Phyllopoda until Metschnikott, in 1865, published an abstract of his essay on the development of Nebalia geoffroyt, which appeared in full in 1868. Unfortunately, his work was published in Russian, but Fritz Miiller, in his “Fiir Darwin,” quotes as follows from Metschnikoff, “that Nebalia, during its embryonal life, passes through the Nauplius and zoea stages, which in the Decapoda occur partly (in Penéus) in the free state.” ‘Therefore, I regard Nebalia as a Phyllopodiform Deca- pod.” In 1872, Claus gave an account, with excellent figures, of the external anatomy of Nebalia geoffroyi; and in 1876, in his valuable work on the genealogy of Crustacea, he described the internal anatomy of the same species. : In 1875, in his “Atlantic Crustacea from the Challenger Expedition,” Willemoes-Suhm placed the Nebaliade among the Schizopoda. While, however, the thoracic appendages of his Nebalia longipes have very narrow respiratory lobes (exites), yet they can be directly homologized with those of the other species of Nebalia, and in all other characters N. longipes does not differ essentially from the other species of the genus. In 1879, in the American Naturalist for February, 1879, and in our “Zoology” (1879) we proposed the name Phyllocarida for Nebalia and 1¢Yr. Leach, in his ‘Naturalist’s Miscellany,’ vol. 1, p. 99, published in 1814, describes it [ Nebalia bipes] more fully than Montagu, and says the species he describes is not uncommon on the southwestern and western coasts of England. As he saw that it constituted a very distinct genus trom any previously given by modern writers, he formed the genus Nebalia to receive it, and adds, ‘in a systematic work this genus would hold a very conspicuous and important place, as it is not referable to any family hitherto established.’ In a paper published soon afterwards by him, in vol. xiof the Linnean Transactions, on the Arrangement of the Crustacea, he assigns its place amongst the Malacostraca, in the order Macroura; in which he is followed by Lamarck, Bosc, and Desmarest, Latreille, Olivier, and Risso; the three latter authors, however, referring the species described to the genus Mysis.” Baird’s British Ento- mostraca, p. 32. 1850. PACKARD.] ANATOMY OF NEBALIA. 433 its fossil allies (see Bibliography), and gave a description of the order and mentioned the types composing it. Nearly a year later, in 1880, Claus, in the last edition of his Zoology, according to Carus’ Yahresbericht, 1880, also suggested that Nebaha represented a distinct order, which he calls Leptostraca. We have not seen the last (fourth) edition of Claus’ Zoology (1882), in which the or- der is noticed. Habits.—The species of Nebalia inhabit the sea at moderate depths. We have dredged WN. bipes on the coast of Labrador in from four to eight fathoms, and on the coast of Puget Sound we collected a sim- ilar species, just below low-water mark, among fucoids. The fol- lowing is taken from Baird’s British Entomostraca: *‘Otho Fabricius tells us that it carries its eggs under the thorax during the whole winter; that they begin to hatch in the month of April, and that the young are bornin May. They are very lively, he adds, and adhere to the mother, who appears then to be half dead. The adult swims in a prone state, using its hinder feet to propel it through the water. They are not very active. Montagu informs us that when moving in the water the superior antenne are in constant motion as well as the abdominal feet, but that the inferior antenne are usually motionless and brought under the body. They are found, according to Leach, on the south- western and western coasts of England, under stones that lie in the mud, amongst the hollows of the rocks; and Mr. McAndrew dredged it from a considerable depth amongst the Shetland Isles.” 1.—THE ANATOMY AND DEVELOPMENT OF NEBALIA. The first published description of the present species was by Kroyer, in his Naturhistorisk Tidskrift (Ser. 2, Bd. 2). It is written in Danish, and not accompanied by any figures. " In Nebalia bipes the body is rather slender and somewhat compressed, the anterior half protected by a carapace, beyond the lower edge of which the broad thin phyllopodiform feet do not project. The carapace.—The head and anterior half of the body, including the thorax and four anterior abdominal segments, are covered by the cara- pace, which on the lower edge extends below the ends of the thoracic feet, covers the basal joints of the antennz, and entirely covers the mouth parts. The sides are compressed, and are drawn together over the body by a large but rather weak adductor muscle (Pl. XXX VII, fig. 6), situated a little in front of the middle of the thorax. There is no large highly specialized adductor muscle connecting the two sides of the carapace, nor any well-marked round muscular impression in the cara- pace, such as is characteristic in the Estheriade ; nor is there any hinge, a still more characteristic feature in the bivalved Phyllopods. On the contrary, aS seen in Pl. XXXVI, fig. 3, representing the carapace re- moved from the body and flattened out, there are no signs of a median hinge-joint. The nature of the rostrum is one of the diagnostic features of this order. In WNebalia, the rostrum is long and narrow, oval, seen from above, terminating in an obtuse point quite far in advance of the head. It is loosely attached to the sinus in the front of the carapace, and thus forms a long, narrow, tongue-like flap, with a free movement up and down. It is thus seen to be rather a movable appendage of the cara- pace than a solid, immovable continuation of it, as in the Decapoda. Upon removing the carapace and flattening it out, it is seen to be readily comparable with the carapace of Ceratiocaris. 28 H A34 GEOLOGICAL SURVEY OF THE TERRITORIES. The eyes.—The eyes are mounted upon a stalk, and thus Nebalia may be said to be essentially stalk-eyed. In this respect it is similar to the eye of the Branchipodide on the one hand, or to the eye of the Decapoda on the other. They are inserted just above and slightly in front of the 1st pair of antenne. The cornea is considerably less in extent than the end of the eyestalk itself, and in this respect differs from the eye of Decapods. The antenne.—The two pairs of antenne are large, well developed, and of nearly equal size in the female, but in the male the second pair extend backward beyond the bases of the caudal appendages. In the 1st pair the stem (scape or protopodite) is seen to be composed of fine joints, the 1st, 2d, and 4th the longest, the 3d and 5th short. From the scape arises the flagellum or endopodite, which has 16 well-marked joints, each joint provided externally with numerous set; and besides, there arises from the 5th joint of the scape or stem a scale- like unjointed appendage, which may be regarded as an exopodite; if so, then the Ist instead of the 2d antenne in the Phyllocarida bear a seale-like exopo- dite; the 2d antenne in Decapoda bearing the exopodite. The outer edge of this exopodite is thickly fringed with numerous long, delicate sete. It thus appears that what corresponds to the sete or protopo- dite of the Ist antenne of Decapods consists of 5 instead of 3 joints. The Ist antenna of Nebalia may be compared with that of the first stage of the larval lobster (Smith, Pl. XV, fig. 8) at the period when the exopodite is short, scale-like, and single-jointed. The 2d antenne have a 2-jointed stem or scape (protopodite), and a single long many-jointed flagellum or endopodite, the basal joint a large one; no exopodite being present, even in a rudimentary form. The Ist and 2d antenne are thus seen to be quite unlike those of the Malacostraca, and to resemble the Copepods, in that the anterior pair are rather the stouter of the two; but in those Copepods with very long antenne it should be remembered that they are the 1st and not the 2d pair, as in the male Nebalia. It will thus be seen that while the anten- ne of the Phyllocarida are entirely unlike those of the Phyllopoda, they are neither closely homologous with those of the Decapoda (Iysis or Cuma) or the Copepoda. The 2d antennz of the male is said by Claus to be very long, and to resemble those of male Cumacee, but upon a comparison the stem of the antenna is in Cuma quite different in the relative length of the three joints. So also, while, as Claus observes, they are like the antenne of the Amphipoda, this resemblance is quite general; on the whole, how- ever, the antenne of both pair bear a general resemblance to the Mala- costracous type; also, on the other hand, they may also be compared with the more primitive Copepodous type. The mandibles (P1. XXXVI, fig. 4; fig. 2, md).—These are remarkable from the small size and weak development of the biting edge or mandi- ble itself compared with the palpus. The oval or biting end of the. protopodite is small, and armed with comparatively few and weak sete, which shows that the Phyllocarida probably feed on decaying animal and vegetable food, which is easily brushed into the mouth by their slight stiff bristles. The palpus, however, is enormously developed, extending out quite to, if not a little beyond, the edge of the carapace (Fig. 1). It is 3- jointed; the 2d a little longer than the basal, and swollen at the base, while the 3d is somewhat longer but slenderer, and edged with a fringe of close-set, rather stiff sete. Though soimmensely developed as to the palpus, and entirely unlike the mandible of the Phyllopoda, in which only the protopodite is developed, it may be com- PACKARD.] ANATOMY OF NEBALIA. 435 pared with the mandibles of the Decapoda, especially of Mysis and other Schizopods,! in which a very long three-jointed palpus is developed. But the very long and large mandibular palpus and very weak protopo- dite may be set down as a diagnostic feature of the Phyllocarida. The 1st maxille (Pl. XXXVI, fig. 2, mzx!; fig. 5, mxz!; 5 a).—These are likewise singular and diagnostic features of this order, as represented by their structure in the Nebaliade. They consist of a small lobe (Fig. 5 a, cv') with about 8 stout sets, and a larger lobe (cx) with the outer edge fringed with long coarse setz, one of which is a large ciliated seta; from this arises, after bending on itself at its base an extremely long and slender multiarticulate process (or endopodite?) which, in the female, is directed upward and backward (Fig. 5 a, en), reaching to the tergum of the basal abdominal segment, and ending in two very long slender sete, while a few other similar setz arise, one from each joint.? In the male of N. geoffroyi, according to Claus, the long setose process is directed forwards and downwards. : The 2d maxille (Pl. XXXVI, figs. 2, 5, ma”).—These are entirely unlike those of the first pair, and unlike the Decapodous or Phyllopod type. They consist of a basal portion composed of four thin, delicate, unequal lobes (Fig. 5, »***), edged with long setz, with two sete twice as long as the others arising from the 4th lobe; from this 4-lobed basal joint or coxopodite arise two appendages, the anterior (exopodite, ex), small, 1-jointed; the posterior (endopodite, en), 2-jointed, the end of the second joint carrying above.5 long, spreading, stout, slender sete. This two- jointed appendage Claus considers as representing the stock of a palpus. This pair of maxillz are quite unlike those of Decapods (Afysis, etc.), as well as those of the Phyllopods, and appear to be another diagnostic feature of the order. The absence of any maxillipedes, or of any rudiments of them, either in the adult or in the embryo, is a negative character of a good deal of importance when we regard the affinities of the group to the Decapods, or the zoéa-form of the same order, where two (Macrura) and three (Bra- chyura) pairs of maxillipedes are present, there being three pairs in the adult Decapod. The eight pairs of Phyllopodiform thoracic feet (Plate XX XVII, fig.3).— The maxillz are directly succeeded by eight pairs of leaf-like thoracic feet, the maxillipedes not being present. The feet all repeat each other in form, and a description of the 3d or 4th pair will answer for the Ist as well as the last. The leg (Fig. 3, 3d or 4th pair) consists of a broad, thin, six-jointed appendage, the endopodite (en), which is fringed with very long delicate sete, those arising from the terminal joint being cil- iated; while a second series of fine stiff setze arise obliquely from the edge. To the second joint of the endopodite are appended a distal or lower very broad thin gill, not quite twice as long. as broad, and which reaches to the end of the endopodite, while situated more exter- nally is a double broad large lobe which corresponds to the exite or fla- bellum of the Phyllopod foot, this flabellum being as long as the entire endopodite, but not quite so broad as the gill. The distal portion of the flabellum is more pointed than the proximal, and, as will be seen by re- ferring to the figure, is more actively engaged in the process of respira- tion. The figure shows by the dotted lines of parenchymatous matter 1Compare G. O. Sars. Monographi over Mysider, 1870; Pl. I, fig. 8. Claus states that the large palpus is very similar to that of many Amphipoda, but apparently overlooks the still closer resemblance to that of Mysis. 2Claus draws attention to the position of this foot as compared with the 2d max- ille (putzfuss) of the Ostracoda. 436 GEOLOGICAL SURVEY OF THE TERRITORIES. the course taken by the blood in passing through the gill and accessory gill or flabellum, and that it must also be partly aerated by the jointed © endopodite; the entire appendage, therefore, as in those of the Branchi- podida, is concerned in respiration. It will thus be seen that the limb is lamellated, but differs essentially from the Phyllopodous limb in that the endopodite is simple, the axis multiarticulate, but sending off no endopodal lobes from the axites, such as form the characteristic feature of the Phyllopodous foot. From overlooking this important and radical difference from the Phyllopodous foot the earlier observers were led to place Nebalia among the Phyllopods. In comparing the thin, lamellar thoracic foot of Nebalia with the thor- acie foot of any Decapod from Cuma to Mysis, and up through the Ma- crura to the crabs, it will be found impossible to homologize the parts closely, though a general homology is indicated, the endopodite of the Nebalia and the gills corresponding in a general sense to those of the Decapods, and itis this lack of close homology more than any other which forbids us from regarding the Nebalide as entitled to take rank under the order of Decapoda, or with any of the Malacostraca. But when we compare the thoracic legs of the adult Nebalia with the maxillipedes of the zoéa of the Decapods, then we can detect a slight and interesting resemblance, but the resemblance and homology is not so close as between the thor- acie legs of the Phyllopods and the maxille of the early zoéa. On comparing the broad lamellate thoracic feet of the adult Nebalia with the rudimentary thoracic feet of the later stages of the zoéa the re- semblance is but slight. Just before the zoéa passes into the adult con- dition the five pairs of thoracic feet of the adult bend out as two-lobed processes; but the resemblance to the leaf-like foot of Nebalia is too re- mote to be of any taxonomic value; and this remote resemblance shows that Nebalia does not belong to the Decapod type. The six pairs of abdominal feet (Plate XX XVII, figs. 4, 5).—Turning to the abdominal feet, we find that they are simple, without gills, and entirely different from the leaf-like thoracic appendages, and we have in this differentiation of true abdominal from the thoracic feet a Mal- acostracan character, one quite unlike the differentiation or blending of the two regions in the Phyllopods. The abdomen is nine-jointed, the segments cylindrical and edged with obtuse spines (Pl. XXXVI, fig. 8.) much as in Copepoda. -The segment succeeding the 8th thoracic is much larger and extends farther down sternally than the 8th thoracic, and bears a large, stout pair of feet, to which the three following pairs are closely related in form. For example, the 2d pair (Pl. XX XVII, fig. 4) consists of alarge, thick, long stem (protopodite) which sends off three appendages, an outer (ex- opodal) stout, blunt appendage, (ex); edged with stout sete externally and more densely on the inner edge with ciliated, delicate sete the mid- dle two-jointed appendage (endopodite, en) is longer and slenderer than the outer, and edged externally with finer sete; a third minute bract-like appendage, Claus says, acts as a retinaculum (Irig. 4, ret.) to connect the two legs of the same pair while the creature is in the act of swim- ming. Intheir general form the abdominal legs appear to resemble the simple biramous legs of the Copepoda, but still more closely those of the Amphipoda, in which, as Claus observes, there is a similar retinaculum. (See also Milne-Edwards’s Crustaces, Pl. 30, fig. 3?.) The 5th and 6th segments of the abdomen bear much smaller, more rudimentary legs. The first pair (Pl. XX XVII, fig. 5) are seen to be two-jointed, the 2d joint long and slender, bearing near the end stout raptorial setz, and on the inner edge slender setz. The 6th pair are PACKARD.] ANATOMY OF NEBALIA. 437 still more rudimentary, one-jointed, and with but few sete, which are stiff and coarse. These resemble the simple, unbranched Sth and last pair of abdominal feet in Copepoda (Calanus ¢). The long, slender terminal segment bears two very long, narrow cer- copods (Pl. XXXVI, fig. 7) ending in one large and several small setz, but there is no telson; the cercopods are simple, the integument entirely smooth, with no striz or any other markings, and they are edged exter- nally with short and internally with long ciliated sete. In the absence of a telson Nebalia differs from Cuma or any other Decapod, and in this respect, and the simple cercopods, shows a close resemblance to the termi- nal segment with its two setiferons cercopods of the Copepoda. Accord- ing to Claus the males differ from the female in WV. geoffroyi in the rather narrower carapace and slighter body, but chiefly in the very long 2d antenne, the flagellum of which reaches nearly to the end of the caudal appendages. The male sexual glands open on the last of the eight thoracic segments, which fact Claus regards as a proof of the agreement of Nebalia with the Malacostracous type. Internal anatomy.—Claus remarks in his “Untersuchungen zur Erfor- schung der genealogischen Grundlage des Crustaceen-Systems” (1876) that in all the internal systems of organs Nebalia is considerably re- moved from the Phyllopoda, and shows an immediate relationship to the Malacostraca, sometimes approaching near the Amphipoda, sometimes _ near the Myside. The nervous system consists of a large two-lobed brain and of a ventral cord extending through all the limb-bearing seg- ments, there being, as shown in Metschnikoff’s Fig. 25 of the embryo, 17 ganglia, corresponding to the 17 limb-bearing segments of the body behind the head. 7. oo s© 10. i) 11. 12. 13. 14. 15, 16. Wie 18. 1Sy 20. 21, 22. 23. 24. 20. Vitl Ss i BpiLifoG RA} EY. PHYLLOPODA. a. LIVING SPECIES. J. L. Friscu, Vom flossfiissigen seewurm mit dem Schild (Beschreibung von allerley Insecta in Teutschland, x, i, Taf. i). 1732. R. RICHARDSON, Part ofa letter congerning the Squilla aque dulcis (Philos. Trans. Royal Soc. 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Caru CLAus, Ueber die Estherien, insbesondere tiber Estheria mexicana (Beitrige zur Kenntniss der Entomostr., 12-25, Tab. ili andiv). 160. C. Cuaus, Ein Australischer Limnadia. Nachrichten von der k. Gesellschaft der Wissenschaften, 6. Miirz 1872. PACKARD.] BIBLIOGRAPHY. 455 57. C. Cxiaus, Ueber den Kérperbau einer australischen Limnadia und itiber das Miinnchen derselben. Zeit. f. wissen. Zool. xxii, 355. Taf. xxix, xxx. 1872. 58. B. von DyBowsSKI, Beitrag. zur Phyllopoden-Fauna der Umgegend Berlius (Wieg- mann’s Archiv f. Nat., xxvi, 195-204, plate). 1860. 59. J. LuBbpock, Notes on some new or little known species of freshwater Entomos- traca (Transact. Linnean Soc. Lond., xxiv, 197-209). 1863. 60. KLUNZINGER, Beitriige zur Kenntniss der Limnadiden (Zeitschr. f. wiss. Zool. xiv, 139-164, plates). 1864. 61. LEREBOULLET, Observations sur la génération et le dévelopement de la Limnadia Pomanel Brongn. (Annales d. scienc. natur., 5. sér. Zoolog., v, 283-303, plate). 1866. 62. A. Friescu, Ueber das Vorkommen von Apus und Branchipus in Boehmen (Ver- handl. d. zool. bot. Ges. Wien, xvi, 557-562). 1866. 63. R. BucuuoLz, Branchipus Grubei Dybowsky (Schriften der phys. 6k. Gesellschaft zu Konigsberg, v, 93-107, plate). 1866. 64. KLUNZINGER, Ueber Branchipus rubricaudatus n. sp. (Zeitschr. f. wissensch. Zool., xvii, 23-33, plate). 1867. 65. E. S. Morst. Proc. Boston Society Nat. Hist., xi, 404. 186668. . 66. E. S. Morse. First Book of Zoology. New York, 1875, 120 (Estheria and Lim- nadia figured). 67. A.E.VERRILL. Descriptions of some new American Phyllopod Crustacea. Contr. to Zool. Mus. Yale College, No. iii. Amer. Journ. Sc., 244, xlvili. 1809. Ann. and Mag. Nat. Hist. London, 1869. 68. A. E. VERRILL. Observations on Phyllopod Crustacea of the family Branchipide, with descriptions of some new genera and species from America. Proc. Amer. Assoc. Ady. Se. for 1869. July, 1870. 69. W. LitisEBORG, Limnadia gigas (J. F. Hermann) forekommande i Sverige in “Porhandlingar af Kong]. Vetenskaps-Akadem.,” Stockholm, 1871, 825-844, 24 plates. : 70. W. LiILLJEBoRG, Synopsis Crustaceorum Svecicorum ordinis Branchiopodorum et subordinis Phyllopodorum. pp. 20. (Reg. Soc. Se. Upsaliensi tradita die v1, Apr. 1877. 71. A. S. PACKARD, JR. Preliminary notice of new North American Phyllopoda. Amer. Journ. Sc. and Arts, ser. 3, ii. August, 1871. 72, A. S. PACKARD, gk. Descriptions of new North American Phyllopoda. Sixth Re- port Peabody Acad. Sc. Salem, Mass., 54. 1874. 73. A. S. PACKARD, JR. Synopsis of the fresh-water Phyllopoda of North America. Rep. U. $. Geol. Survey Terr. (F. V. Hayden in charge) for 1873. Zoology, 613. 1874. 74. A S. PackarD, gr. New Phyllopod Crustaceans. American Naturalist, ix, 311. May, 13875. 75. A. S. PAcKARD, JR. Explorations of the Polaris Expedition. Amer. Nat. Jan- uary, 1877. 76. A. S. PACKARD, JR. Descriptions of new Phyllopod Crustacea from the West. Bulletin U. S. Geol. and Geogr. Survey (F. V. Hayden in charge), iii, No. 1, 171. April 9, 1877. 77. A. S. PACKARD, JR. Occurrence of the Phyllopod Eubranchipus in winter. Amer. Nat., xii, 156. March, 1878. 78. A. S. PACKARD, JR. Notes on Phyllopod Crustacea. Amer. Nat., xiv, 53. Jan- uary, 1880. 79, A. S. PackarD, JR., A new Distomum parasite in the egg-sacks of Apus. (Disto- mum apodis) American Naturalist, 142. Feb. 1882. 80. FrreprRICH BRAUER, Beitriige zur Kenntniss der Phyllopoden in Sitzungsberichte der k. Akad. d. Wissensch., Ixv. Band, lte Abth., 1 plate, 1-13. Wien, 1872. 81. Frirpricu Braver, Vorliinfige Mittheilungen tiber die Katwicklung und Leben- sweise des Lepidurus productus Bose. In Sitzungsb, d. k. Akad. d. Wiss. Wien, Band Ixix, 1te Abth. 1-12, 2 plates. 1874. 82, Frrepricu BravEr, Beitriige zur Kenntniss der Phyllopoden. Sitzungsberichte der k. Akad, d. Wissen. Wien., Math-Naturw., Classe, xxv. Band, v. Heft, 583, 8 Taf. 1878. 83. G. O. Sars, Bemerkninger om de til Norges Fauna horende Phyllopoder in Vi- densk. Selsk. Forhandlinger, 3-7. 1873. ~ 84. F. SPANGENKERG, Zur Kenntniss von Branchipus stagnalis. Zeits. fiir wissen. Zool., xxv. Supp. Heft, 1, Taf. i-iii. 1575. 85. F. SPANGENBERG, Bemerkungen zur Anatomie der Limnadia Hermanni Brongn. Zeits. f. wissen, Zool., xxx. Supp. Band, 476. .Mai, 1878. 86. Hernricu LENZ, Estheria californica Packard. Inaug, dissertation, 24-40, 2 plates. Rostock, 1876. 87. H. Nirscur, Ueber die Geschlechtsorgane von Branchipus Grubii. Zeits. f. wis- sen. Zool., xxv. Suppl. Band, 281. Taf. xxii, Dec. 22. 175. 456 GEOLOGICAL SURVEY OF THE TERRITORIES. 88. 89. 90. 91. 96. 97. 98. 99. J. A. RYDER, Description of a new species of Chirocephalus (Ch. Holmani). prorat of the Academy of Natural Sciences, Philadelphia, 3 wood-cuts, 148- 149. 187 J. A. RYDER, Description of a new Branchipod. Proceed. of the Acad. of Nat. Sciences Philad., 200-202 (Streptocephalus Sealii), 1 wooa-cut. 1879. J. WLADIMIR SCHMANKEWITSCH. On Branchipus. Schriften der iii, Versammlung Russisch. Naturforschen, Zoolog. Theil. J. WLADIMIR SCHMANKEWITSCH. Sitzung der neurussischen Gesellschaft der Naturforscher in Odessa, Sept. 20, 1574, ii, Th. ii. 2. W. J. SCHMANKEWITSCH, Ueber das Verhiltniss der Artemia salina Miln.-Edw. zur Artemia Muhlhausenii Miln. Edw. und dem Genus Branchipus Schaef. Zeits. f. wissen. Zoologie, xxv. Supp. Heft, 103, Taf. ii. 1875. . J. WLADIMIR SCHMANKEWITSCH, Zur Kenntniss des Einflusses der Husseren Lebens- bedingungen auf die Organisation der Thiere. Zeitsch. itir wissensch. Zoologie, xxix, 429-494. 1877, . Cart I. Giss“teR. Description of a hermaphroditic Phyllopod Crustacean (EKu- branchipus vernalis), American Naturalist, 186, xv. February, 1881. 5. CARL F. GIssLER. Evidences of the eifect of chemico-physical influences in the evolution of Branchiopod Crustaceans. American Naturalist, 280, xv. April, 1881. b. FosstL PHYLLOPODA. T. Rupert JONES, A monograph of the fossil Estherie. Lond. Paleont. Society, 134, 5 plates, 4°. 1862. T. RuPERT JonrES, On fossil Estherize and their distribution (Quarterly Journ. Geol. Soc. Lond., xix, 140-157.—Natural Hist. Review, 262-276. 1863. T. RUPERT JONES, Note on Estheria Middendorfii (Quart. Journ. Geol. Soc. Lond. xix, 73). -1863. H. Laspryres, Das fossile Phyllopoden-Genus Leaia Jones (Zeitschrift der deut- schen eeolow. Gesellschaft, 733-746, 1 plate). 1870. 100. A. S. PACKARD, JR., A fossil Phyllopod Crustacean from the Quaternary clays of Canada. American Naturalist, 496, xv. June, 1881. 101. JoHN M. CLARKE, New Phyllopod Crustaceans from the Devonian of Western New mn Powe I York. Amer. Journ Sc., 476, xxiii. June, 1882. PHYLLOCARIDA. a. LIVING SPECIES. . Henri MILNE-EpWarps, Annales des Sciences Naturelles, tome xiii, 1828. Henri MILNE-EDW: ARDS, Annales des Sciences Naturelles, 2. sér., tome iii, 1835. . Henri MILNE-EDwarbs, Histoire Naturelles des Crustacés, tome iii, Paris, 1840. . HenRIK Kroyer. Karcinologiske Bidrag. Naturhistorisk Tidskrift, ser. 2, ii, 436, 1847. . Evtas METSCHNIKOFF (Abstract of Embryology of Nebalia). Sitzungsberichte der Naturforscherversammlung zu Hanover, 1865, 218. Also Keferstein’s Jahresber- icht, 1867. . ELIAS METSCHNIKOFF, Development of Nebalia (in Russian). 1868. 8°, 48, 2 plates. . Fritz MULLER, Fir Darwin. Leipzig, 1864. 5°. (Facts and Ar, euments for Dar- win. By Fritz Miiller, with additions by the author. Translated by W. S. Dallas. London, 1869), 12, 144. . C. Ciaus, Ueber den Bau und die systematische Stellunge von Nebalia, nebst Be- merkungen iiber das seither unbekannte mannchen dieser Gattung. (Zeits. f. Ww. Zoologio, xxii, 323, Taf. xxv). 1872 . C. CLAUS, Nachrichten von den koénigl. Gesellschaten und der G. A. Universtiit, zu Gottingen, No. 10, 1871. . C. CLAUS, Untersuchung gen zur Erforschung g der genealogischen Grundlage des Crus- taceen- “Systems. Ein Beitrag zur Des cendenzlehre. Wien, 1876. . R. VON WILLEMOES-SUaM, On some Atlantic Crustacea from the Challenger Expe- dition. III. @n a Nebalia from the Bermudas, pl. vi. Trans. Linn. Soc., 2d ser., i, 26, 1875. A. 8. PACKARD, jr., The Nebaliad Crustacea as types of a new order (Phyllocarida) American N aturalist, xy, 28, Feb., 1879. Annals and Mag. Nat. Hist. London, 1880. A. S. PACKARD, jr., Zooleee for High Schools and Colleges. New York, Dec., 1€79. (Order Phyllocarida described.) PACKARD.] BIBLIOGRAPHY. 457 b. FOSSIL SPECIES. 14. McCoy, Annals and Magazine of Natural History, ser. 2, vol. iv, 412, 1850. 15. McCoy, Synopsis of British Palzeozoic Fossils Cambridge Museum, fasc. i, 156, Pl. I, K, 1851. 16. McCoy, Quart. Journal of the Geological Society of London, Feb., 1853, 13, 1853. 17. JAMES HALL, Paleontology of New York, ii, 320, pl. 71, 1852. 16. JAMES HALL, Paleontology of New York, iii, 420, 1859. 16th Ann. Rep. Stat. Cab- inet of Nat. Hist, New York, App. D. Albany, 1863. 19. R. MURCHISON, Siluria, 236, 1854. 20. J. SALTER, On some new Crustacea from the uppermost Silurian Rocks. Proce. Geol. Soc. London. xii, 26, 1856. Quart. Journ. Geol. Soc. London, 33, xii, Feb., 1856. J. SALTER, On new fossil Crustacea from the Silurian Rocks, Annals of Natural Hist., 3d ser., v, 153-162. March, 1860. 22, J. SALTER, On Peltocaris, a new genus of Silurian Crust. (Quart. Journ. Geol. Soc. Lend., xix, 87-92), illustr., 1863. J. SALTER, On some tracks of Lower Silurian Crust. (Quart. Journ. Geol. Soc. Lond., xix, 92-95, illustr.), 1863. ‘ 24. J. SALTER, Memoirs of the Geological Survey of Great Britain, iii, 294, 1866. 25. ANGELIN, Pal. Scandin, Suppl. Pl. B, 1860. 26. Henry WoopWARD, On the oldest known British Crab; notes on the species of the genus Eryon Desm., and on a new genus of Phyllopodous Crustacea (Quart. Journ Geol. Soc. Lond., vol. xxii, 493-505, 2 plates). 1866. 27, HENRY WOODWARD, On some new Phyllopodous Crustaceans from the Paleozoic rocks (Geolog. Magazin London, vol. viii, No. 3, 3-6, plate iii, 1-5). 1871. 28. HENRY WOODWARD, On Fossil Crustacea (Geological Magazin Lond., vol. viii, No. 11. 1-4). 1871. 30. J. J. Brespy, Thesaurus Silur., 73, 1868. 31. JOACHIM BARRANDE, Systéme Silurien du Centre de la Bohéme, vol. i, suppl. Prague 1572, 435-459. (Also Jahrbuch, von Leonhard und Bronn, Heft iii, 322, 1853. ) 32. HENRY WOODWARD, Geological Magazine, ii, 401, pl. xi, 1865. 34. J. SALTER and HENRY WOODWARD, Chart of Fossil Crustacea, 1865. 29. HENRY WOODWARD, Geological Magazine, iii, 203, pl. x, 1866. 33. R. P. WHITFIELD, Notice of new forms of Fossil Crustaceans from the Upper De- vonian Rocks of Ohio, with descriptions of new Genera and Species. Amer. Journ. Se., 3d ser., xix, 33. Jan., 1880. 35. R. P. WAITFIELD, Geol. Surv. Ohio, Paleontology, iii. 36. S. H. ScupprrR, Rhachura, A new Genus of fossil Crustacea (Rhachura venosa. Seudder. Danville, Ill., Bed, No. 14, Coal Measures). Proc. Boston Soe. Nat. Hist., xix, 296, Pl. 9, fig. 3, 32. March, 1878. 37. Joun M. Ciarxn, New Phyllopod Crustaceans from the Devonian of Western New York. Withaplate. Amer. Journ. Sc., 476-8, xxiii. June, 1882. APPENDIX. A.-ON ARTEMIA FERTILIS VERRILL, FROM GREAT SALT LAKE, UTAH TERRITORY.! By Pror. C. TH. VON SIEBOLD, of Munich. [Translated by Dr. Phil. Carl F. Gissler, of Providence, R. I.] Having positively convinced myself several years ago that Artemia salina, which is known to inhabit in countless numbers shallow brackish water ponds along the shores of Europe, in those localities propagates parthenogenetically without males,? I put to myself the question whether this was also the case with other species of the genus Artemia. To solve this problem I conceived the idea of procuring live specimens of the brine-shrimp from the Great Salt Lake of Utah, which I knew to occur there in both sexes and in great numbers. The middle of March this year (1876) I obtained, through the kindness of Dr. Hermann A. Hagen, of Cambridge, Mass., a considerable quantity of dried mud from the Great Salt Lake, with which I experimented in the following manner: Toward the end of March, of the same year, I divided some of the dried mud into several shallow glass jars, pouring over it on the 6th of April artificially prepared sea-water, using common hydrant- water and Reichenhaller brine. On the 8th day of April already the water in one of these jars swarmed with Nauplii, the hatching of which I eagerly watched, as I observed many brown Artemia eggs on stirring up the mud infusions. The brood prospered excellently, the mud being evidently impregnated with organic matter, the latter serving as food during their different moults and stages of development; and already on April 16, about eleven. days after hatching, indications of sexual characters could be perceived, in the male sex perceptible by a stouter swelling of the claspers. This sexual character, after which the dif- ferentiation of the organs of reproduction appear, refers to the organs of copulation only, and not to the true fructification organs, and was for my experiments of great importance. This early differentiation of the male and female individuals of Artemia fertilis gave me occasion to distinguish the males from the females, and to keep them separate al- ready at atime before the internal sexual organs, the testicles of the males and the ovaries of the females, began to develop. The second pair of legs of the six-footed Nauplius is, after the first moult, promi- 1Ueber die in Miinchen geziichtete Artemia fertilis aus dem grossen Salzsee von Utab. Von Prof. C. v. Siebold in Miinchen. Separatabdruck ans den Verhandlungen der 59ten Jahresversammlung der Schweiz. naturf. Gesellschaft in Basel, 1876. Basel, 1877. 8°. pp. 16. So much that is of great interest in connection with the doctrine of evolution and of parthenogenesis has been published regarding the Phyllopods, that we avail our- self of the kind permission to insert, as an appendix, the most important papers which have appeared. Iam indebted to Dr. C. F, Gissler for this and the following transla- tions and abtracts. 2See my lecture on “‘ Parthenogenesis of Artemia salina,” in the Sitzungsberichte der mathematisch-physikalischen Classe der K. Akademie der Wissenschaften, of June 7, 1873, p. 163. 459 460 GEOLOGICAL SURVEY OF THE TERRITORIES. nently developed, serving as a rudder organ; after the subsequent moults this organ becomes gradually shorter, less movable, bent down, loses its bristled margin, and in the females is transformed into two © small, scarcely movable, tongue-like bent processes, while in the males the same develops itself into disproportionately large claspers with broad lobes, functionating as a catching and clasping apparatus. These robust claspers, bent downwards and backwards, betray the male sex, as above stated, in the earlier stages by an incipient swelling of the said rudder organs, while the same, after their hystolytic degeneration, re- main small in the females. In this way it was easy for me early to dis- tinguish the males from the females and, significant for my experiments, to keep them apart. The growth and prosperity of the carefully-separated sexes proceeded well in various jars with artificial sea water, and pains were also taken to add only boiled Utah mud to prevent any Artemia eggs from hatch- ing. Without this precaution.I would eventually have received younger broods of different sexes together with the older ones, already kept apart, which would have interfered with my experiments, in which latter the utmost certainty was required to prevent the meeting of the two sexes before the setting in of concupiscense. Having raised a large number of carefully-watched virgin individuals in the above mentioned manner, I waited the period of concupiscence in one-half of their num- ber without giving them occasion to come in contact with any males, while the other half of virgins I placed together with a number of ma- tured male individuals for the purpose of getting fertilized by them. I sneceeded in this, since thé males very early, as already stated, betrayed their future sex and were vigorously grown up, and gave repeated indi- cations of sexual desires. They manifested the latter in their pugna- cious behavior, embracing themselves with their powerful claspers in such a manner as if they would perform copulation; many of them clasped other males, no matter how they struggled against it, and with such a violent fervor that they, as may be assumed, applied the claspers on almost every part of their body. Such couples remained entangled for several days, Swimming around in the most unnatural positions. The testicles, filled with whitish zodsperms, presented themselves to the naked eye through the translucent body. I selected the most vigor- ous individuals, placing them ina jar together with boiled-up Utah mud and a number of virgin Artemia, and had then very soon the pleasure to see that they did not refuse the ardent embraces of the males, the females making no efforts to free themselves of their burden. The male with its claspers embraces the postabdomen ‘of the female from the back, which region appears swollen by the ovisac. In this way both individuals, bearing their abdomens parallel above each other, swim about as if animated with but one will. From time to time such a couple swims along the surface of the mud, turns around its longitudinal axis. dorsal side up, thus whirling up the loose mud for the purpose of obtaining food. Occasionally the male, utilizing the embrace of the female, bends its postabdomen around for the purpose of inserting its two protrusile cylindrical copulative organs into the female genital orifice, whereby the closest contact with the female, as well as an afflux of spermatic particles, was effected. The actual process of copulation, as closely observed by me, was interrupted after shorter or longer intervals, but in incessantly long- continued embraces it was often repeated. One of these couples hung together for three days. After copulation ensued, I transferred those females which were abandoned by their males and which females I re- PACKARD. ] ARTIFICIAL REARING OF THE BRINE SHRIMP. 461 garded as fecundated into a new jar, into which they could eventually deposit their eggs. But to be sure that no new brood of Artemia was developed out of the Utah mud added as food, I again took the pre- caution to use only well-boiled mud in which any possible eggs would then be destroyed. The fecundated Artemia females, however, con- tinued to prosper in their new jar, and I soon perceived the activity of their inner generative organs. This activity manifested itself very soon in the two blind ovarial strings situated in their postabdomens; in the interior of those strings white, uniseriately-placed ovarial germs came into view, which latter grew more and more, their places of contact be- coming flattened. All these eggs in their complete form possessed neither a germinal vesicle nor_a yolk-skin. The latter is not formed until the uncovered eggs have entered the upper bent-inward-and-back- ward end of the ovarial strings, and then it represents a very tender trans- lucentand homogeneousegg-membrane. I should call these bent terminal portions of the ovarial tubes oviducts, since they enter after a short course a capacious cavity, the latter certainly functionating as an uterus. The uterus possesses in its walls a very complicated muscular appa- ratus, which, through its active contractions, moves the contents of the uterus in various ways. One can now also observe six cell complexes in three pair of groups on the right and left behind each other, divided and fastened to the uterus walls, which in their organization and mean- ing fully correspond with the egg-shell glands, as observed and de- scribed’ by me in Artemia salina, only with the difference that in Artemia fertilis three pairs, in A. salina only two pairs of such shell- glands occur. These glands at first appear perfectly colorless, becom- ing gradually amber-yellow, finally assuming a rust-brown color, with which coloration the secreting function of these glands begins. It was now interesting and striking to me in these investigations that the first lot of eggs that entered the uterus through the oviduct, which eggs were surrounded by but a delicate yolk-membrane, did not yet receive any hard egg-shells, although they were incessantly moved to and fro by the muscular walls of the uterus. They remained without shells, because the shell-glands had not yet discharged their contents into the uterine cavity. Un the other hand, to my greatest astonishment, a perfect segmentation process was going on in the uncovered eggs, which could be closely followed through the tender and transparent yolk-skin. Finally, I perceived the red eye-dot of the now developed Nauplius through the yolk-skin, soon afterwards the entire brood of Nauplii escaping and rowing about in the water. Curiously enough, this parturitive act did not repeat itself in all those females of Artemia which gave birth once, although their uterus was repeatedly filled with tender-skinned eggs; in short, all fertilized females of Artemia fertilis became, after first giving birth to live young ones, from this time ovip- arous.”, Whether now all females of Artemia fertilis show the pecu- liarity of always producing live young ones at the first process of propagation and then become oviparous, I can give no decisive answer. The observation seems to me important, which I here, though already mentioned, again repeat, that in raising Nauplii from the ‘“ Dauer- 1Opus citatum, p. 191. Ki ‘ , 27 had already occasion to make similar observations on A. salina, and refer to p. 190 of op. citat., and there I attempted to express presumptions as to the causes which induce the females of Artemia at one time to be viviparous and at other times ovipa- rous ; the correctness of those conjectures I cannot warrant, since I have not yet ac- quirerl the necessary amount of experience on these striking phenomena, 462 GEOLOGICAL SURVEY OF THE TERRITORIES. eggs”! contained in dried Utah mud, male as well as female Artemie, and both in about the same number were obtained. To these observa- tions I have to annex the following, which, as regards the questions what sex issues in the different manners of propagation in the Naunlii, in future will turn out to be important. Namely, lI refer to the fact that also those Nauplii, which the fecundated, primiparous females of Ar- temia fertilis, raised from ‘ Dauer-eggs,” yielded in exactly the same manner, like those Nauplii hatched from ‘‘Dauer-eggs” contained in Utah mud, male and female individuals of Artemia fertilis. Concerning the manner of propagation going on after (emmalig) vivi- parturition and oviposition of the fecundated females, I have to say that this process of oviposition occurs in the same manner and with the same repetition as observed by me in non-fertilized females, and which I shall describe later. As the second part of my report on the domestication (Zeuchtung) of Artemia fertilis 1 have to mention experi- ments through which I tried to force this Branchiopod to produce par- thenogenetic generations. In how far I did or did not succeed in these experiments I cannot yet call to account, since I till now could realize only preparations and introductions for the same. I only want to state how | succeeded in obtaining the material with which I could convince inyself whether Artemia fertilis, like A. salina, possesses the peculiarity under certain circumstances to propagate parthenogenetically. It was easy for me to procure the necessary material, since I kept separate, as already stated, a jar with Artemia, which showed in their earlier devel- oping stages indications of yielding female individuals. From this jar I selected such females in whieh the first traces of concupiscence were noticed, and those I raised separately in a jar with brine water and boiled Utah mud, watching them carefully to prevent any access of mnales, and to let them, as genuine virgins, become concupiscent.? At the time when in these isolated virgins the generative organs attained maturity, which showed itself in the ovaries distended with germs, my particular attention was directed to the jar containing them. There I noticed that in these virgins the eggs entered from the ovaries into the oviduct, whence they accumulated in the uterine cavity, during which time the six above-mentioned shell-glands assumed a brown color. Later on the amber-colored secretion of the glands discharged into the uterus, flowing around the tender-skinned unfecundated eggs, which latter, kept in rhythmic motion by the contractions of the muscular walls 1 Above I make use of the word ‘“‘ Dauer-eggs” (or permanent eggs) avoiding the hitherto customary specification ‘‘ winter-eggs” as not quite proper. Of course (allerdings) most Phyllopods deposit two difterent kinds of eggs, one kind of which develops soon after being deposited, while the other kind hatches after. a very long time, and in our climate, in most cases, after hibernation. But those latter eggs can also endure two or more winters under casual external conditions, if the neces- sary impulse from outside for the hatching of the eggs continues; I mean to say when the suitable moisture, giving action and completion for the development of those Phyllopods, does not come into effect. In this way it is accounted for that in such pools serving as a habitation for Phyllopods, but which remain dry for several years and which afterwards again become filled with water, the long disappeared Phyllo- pods suddenly reappear, as the there buried winter eggs (or better) ‘‘ Dauer-eggs,” Paes the influence of the water become animated to live activity out of the latent condition. 2'To demonstrate during my lecture I prepared three jars with mud and salt water, into which I divided three different objects concerning Artemia in the following man- ner: One jar contained several full-grown males, the second jar contained fertilized egg-bearing females, together with two entangled copulating couples, while the third jar, contained virgin females, bearing non-fertilized eggs. These Artemiz arrived in _ goode condition, after being conveyed in their jars from Miinchen to Basel, and there could be exhibited alive during the lecture. PACKARD.] PARTHENOGENESIS IN ARTEMIA. 463 of the uterus, became darker and darker and surrounded with a hard brown shell, so that the non-fecundated, differed neither in form nor color or structure from the fecundated ones. The virgin Artemiz depos- ited their eggs some time afterwards, dropping them into the mud at the bottom of the jar. The uterus of such unfertilized females appeared to be empty after the eggs were dropped; their shell-glands were pale, but their ovaries again contained new germs, which gradually devel- oped, while the pale shell-glands, after some time, again assumed their _brown color, and [surmised that they prepared themselves once more for ovipositing non-fecundated eggs. The same process reoccurred several times in virgins, the latter not differing therefore in this respect from fecundated ones. In this manner I succeeded in accumulating a large number of non-fecundated eggs in the mud of the jar prepared for the concupiscent, non-fertilized females. I must now draw your attention to the fact that such oviparous virgins were never viviparous before depositing eggs. For the success of my experiment on parthenogenesis this was a bad omen. It is evident, however, that the primiparturition of live young ones is not realized in virgin females of Artemia fertilis ; but it is, nevertheless, possible that the ‘“ Dauer-eggs” dropped by the virgins possess the peculiarity of developing themselves without fertili- zation, and do yield females, and therein we would have again a con- . tribution to our knowledge on the distribution of parthenogenesis. I Shall preserve during the coming winter (1876~77) the different kinds of dried mud which are partly impregnated with fertilized, partly with non-fertilized ‘* Dauer-eggs” of Artemia fertilis, for the purpose of examining next spring whether the mud with fertilized eggs alone, or besides it, also the mud with non-fertilized eggs, will yield Nauplii, when it will be of importance to learn from what set the parthenogenetic Nauplii develop themselves. B.—PROF. CARL THEODOR VON SIEBOLD ON PARTHENO- GENESIS IN ARTEMIA SALINA.! ABSTRACT. By Dr. C. F. GISSLER. Owing to the remarks expressed two years ago in my paper “ Beitrage zur Parthenogenesis der Arthropoden” (Leipzig, 1871, p. 197), I am in- debted to Prof. Carl Vogt, of Geneva (Switzerland), for a lot of live in- dividuals of Artemia salina, which arrived at Miinchen August 27, 1872. I was very pleased to have received seventy live and five dead speci- mens, together with a number of larve, in a jar of salt water. All the full-grown individuals were females, which was also the case with a num- ber of Artemiz Dr. Vogt received from Professor Martins at Cette. I observed that in all the seventy specimens thus obtained the egg-sae was filled with embryos. The various behavior of this brood attracted my special attention. Having dissected the egg-sac of a dead individual, I noticed several live embryos escaping from the same, together with a few pear-shaped bodies of orange color sinking to the bottom. The lat- ter proved to be also embryos inclosed in a homogeneous thin egg skin. The outlines of the inclosed embryos could be distinctly seen through the egg skin, as well as the motions of the embryo. Such viviparous 1“ Sitanngsberichte der mathematisch-physicalischen Classe zu Miinchen, 1873, Heft. I.” 464 GEOLOGICAL SURVEY OF THE TERRITORIES. Artemiz I also observed amongst the other live specimens. After the escape of the brood the egg skins remained in the egg-sacs. But many Artemiz proved to be also oviparous. The egg-sac in such oviparous: specimens then contained brownish spherical, hard-shelled eggs. In breaking this brittleshell between two glass slides the homogeneous inner egg skin could be noticed. Joly, who also observed this mode of multi- plication, supposed the season of the year had something to do with it. Vogt noticed that they became oviparous when kept in a more capa- cious vessel, and viviparous when kept in small jars. I, myself, did not succeed in raising more than two generations. Not a single male indi- vidual was obtained from the young Artemiz received as viviparous generation; only 35 females attained sexual maturity. Of these 35 females, on ‘the 20th of October the largest ones had soft, white eggs in the ege- sac, which became gradually ‘brown in a few days; some had their eggs deposited on November 5, involving at the same time a cer- tain mortality among my specimens, all having died by November 21, 1872. The deposited egg did not hatch. After this unsuccessful attempt I concluded to get some more fresh material, which was forwarded to me through the kind intermediation of Duke Carl Theodor of Bavaria, of whose active interest in natural science I was aware. On the 3d of December I received two bottles with 50 live Artemis, which were collected near Capodistria by Dr. Syrski, of Triest, also a large bottle of marine mud and fresh sea water. The Artemiz were, though dead, still of a fresh appearance. They were all females, and their egg-sacs were crammed with brown eggs. After re- moving the eggs I placed them in a shallow vessel with marine mud and sea water. Already four days afterwards I observed new-born em- bryos swimming about, and mauy more toward evening. I divided them on December 12 in two jars, marked with a and b. Owing to the marine mud containing much organic matter (which was probably not the case in the former experiment) they prospered well, shed their skins often, and developed into females. The jar destined for the specimens origin- ally received from Capodistria I marked with e. The embryos hatched therein from the eggs of the killed original specimens and those embryos I divided into the two jars a and b. That the embryos thus hatched did not all come from the eggs taken from the egg-sacs of the original dead but still fresh specimens is quite obvious, as the marine mud very likely also contained eggs of Artemia, which were thus brought to development. TF inally I got fully convinced of this view, as in the larger jars a and b gradually an immense number of young Artemiz grew up, whose number by far exceeded the sums of those embryos which I took from jar e, and which I placed into the jars aandb. In no case could this superfluous brood have originated from the older, fully-raised embryos, as the latter were not yet sexually ma- ture when I noticed the bulky throng of continually forthcoming em- bryos. On examining a quantity of the remaining mud from Triest I found many Artemia eggs. The hatching of embryos in jar e kept on from December 7, 1872, till March 23, 1873. Some marine mud I placed also into jars a and b, and care was taken to replace the evaporated salt water, a water of 1° Beaumé having been used for this purpose. On January 12, 1873, I counted 31 full grown and 136 younger individuals, not counting the very youngest ones. In the ovaries of seven adult females I noticed on January 19 the first traces of egg-formation; on the 24th I saw the yellowish eggs in the ovaries in 18 adult ones; 4 of them had yellowish eggs in the egg-sacs, and 3 had brown ones; on January 26th 3 more had also brown eggs in the egg-sacs. PACKARD. ] PARTHENOGENESIS IN ARTEMIA. 465 To verify whether those eggs were really unfertilized, I arranged another large jar with artificial sea water and marked it with f. Into this jar I placed some Triest marine mud which had been previously boiled to destroy any eggs possibly contained therein. The adult females placed in this jar prospered well. The number of adult females in jars a and b continually increased, counting, on February 1, 24 fe- males, all with brown eggs in their egg-sacs. Six of these females dropped their eggs on February 5, their ovaries again showing activity. IT again arranged another jar, bearing the letter h, placing previously boiled mud into it and those 6 females, whose egg-sacs, on February 16, contained for the second time brown eggs, and again the same day I placed 8 more specimens into it, taken from jar /, which afterwards prepared themselves for a third oviposition, so that 1 was urged to take for those 14 females another moderately large jar, bearing the leiter 7, to allow them to deposit for a third time. On March 2 this jar 7 was arranged with the 14 females, the latter depositing their eggs during March; on April 15 ajar marked mwas prepared with boiled mud, placing 2 females into it from jar 7, which were about to deposit for the fourth time. On May 4 one of the two deposited for the fourth time, and al- though a fifth series began to form, I did not prepare another jar; the specimen showed great weakness, and died subsequently. As a matter of course the females taken from jars a and b multiplied in the jars f, h, i,m. In jar f, out of which I took, up to February 28, 14 females and placed them into jar h, I counted, on April 6, 39 females. It would be too tiresome to put down here all the notes as I wrote them down seriatim in reference to further development of Artemia, and I shall here briefly state the result of my experiments. The eggs were for the greater part on the surface of the muddy bottom. On March 16, being the 40th day after my first raised virgin Artemiz deposited their eggs, I noticed two embryos of the Nauplius-stage, as tigured by Joly. For the sake of maintaining stricter control ot the embryos, of whose parthenogenetic origin I had to be fully convinced, I placed these, as well as all those later hatched in jar f, into a smaller jar, g, with some previously boiled Triest mud. On March 24 I had eight such embryos in jar g; counting on March 30, 22; and up to May 10 I had transferred 71 embryos from jar f into jar g. Henceforth the de- velopment in jar f increased rapidly (May 11, hatched 25, and May 12, 49 embryos), so that up to May 23 I obtained from jar f 402 embryos. In this manner I verified that from eggs deposited by virgin females of Ar- temia salina, which were not fertilized by any male sperm, a brood can de- velope. The empty egg-shells were found to be partly floating on the surtace or hidden in the mud at the bottom. The fresh unhatched egg never swam on the surface, and the empty egg-shells on the bottom all showed a crack. Seventeen embryos were removed from jar g and placed in a jar marked k, with a quantity of prepared (boiled) Triest mud. This was done for better observing the sexual development. Of these 17 indi- viduals 5 were nearly full grown on April 30, with no indication of ova- ries, though with beginning egg-sac formation; two other individuals of those 17 Artemiz did not yet show, though full grown, any sexual differentiation. On May 10 I transferred from jar k those specimers which approached sexual maturity into a jar marked 0, together with some unprepared fresh-water clay-mud. These 14, in jar o transferred Artemiw develop- ing into egg-bearing females, prospered well in the salt water of the new jar, and filled, as usual, their intestine with mud as if they had had ma- 30 H 466 GEOLOGICAL SURVEY OF THE TERRITORIES. rine mud. I had to take fresh-water mud because the marine mud be- gan to show signs of decomposition. On May 22 the four oldest individuals.in jar o had brown eggs; also all the others attained maturity by May 29, so that I was sure that these 15 females would soon deposit for the first time their eggs. How many successive generations of Artemia salina retain the fac- ulty to reproduce parthencgenetically without males remains to be ex- amined. Joly made his observations with Artemiz from’ Southern France in 1840, and supposed that these Artemize must be either her- maphroditic, or, if really males existed, that a single fertilization was sufficient for many generations. It would be of interest to re-examine the specimens of Artemie of the localities cited in literature of the years 1840, 1755 (Schlosser), 1830 (Thompson), 1851 (Leydig). Very likely the result would be that par- thenogenesis in Artemia often occurs. The examination of the ovaries and the occurrence of viviparous and oviparous individuals led me to the conclusion that oviposition appears in Artemia only when the egg-shell glands have so fully developed that the necessary quantity of congealing matter can be recreated, as only by this can the eggs obtain a solid, durable shell. Surrounded with such a shell the eggs obtain the power, hidden away in mud or even pertectly dried up, to endure the most unfavorable external condi- tions and preserve the faculty of development after long periods of time. But if the development of the egg-shell glands has not been fully attained the conditions for the formation of a solid and durable shel! are wanting. The eggs ef such Artemiz then only receive a very thin ecg skin, in consequence of which the favorable influences for the de- velopment of the embryo will act upon the egg contents from outside, thus accelerating the embryo formation. C.—ON THE RELATION OF ARTEMIA SALINA MILNE-ED- WARDS TO ARTEMIA MULELHLHAUSENIL MILNE-ED- WARDS AND TO THE GENUS BRANCHIPUS SCH AIF- FRR. By W. J. SCHMANKEWITSCH.! {Translated by Dr. C. F. Gissler. With Plate XXXIX.] In the session of the Neorussian Society of Naturalists at Odessa, held September 20, 1874, I made an addition concerning this matter to the observations made in former years, and now I have again to com- municate the following later results. I shall here briefly state that Artemia salina M. Kdw., Joly (Branchipus arietinus Grube var. Schman- kewitsch. Artemia arietina Fischer var. Schm.), a very variable form, yields not only by domestication but also in a state of nature even at a gradually increased concentration of the water, a form similar to Arée- mia muehlhausenit Milne-Edw., Fischer, which I had occasion to observe in the closed Kajalniker Salt Lake (Andreewsky-Liman) near Odessa during the years 1871 to 1874, inclusive. in 1871, on the oceasion of a great spring flood, the embankment which separated the lesser saline water of the upper portion of the Ku- jaluiker Lake from the more saline portion of the lower part of the same lake broke, whereby the water of the latter became diluted to 8° Beaumé. At the same time Artemia salina appeared in great numbers, probably ! Zeitschrift fiir wissensch. Zoologie, xxv, ltes Supplementheft, 1875. PACKARD. ] TRANSFORMATION OF ARTEMIA. 467 brought along with the flood from the upper portion as well as from the surrounding brine ditches near the same. After restoration of the embankment the density of the water of the lower part rapidly increased, showing already in the summer of 1872 14°, in 1873 18°, at the beginning of August 1874, 23.59, and after a continued drought in September of the same year 25° ‘of Beaumé’s areometer, at the latter time the lower part of the lake beginuing to deposit salt. Simultaneously Artemia salina gradually degraded from generation to generation, so that toward the end of the summer of 1874 the majority of individuals were without furcal lobes, showing then all the specific characters of Artemia muehthausenit (Fig. 6). In 1871 Artemia salina, or better, one of its varieties, had moderately large furcal lobes, and on each of them eight to ten, seldom 15, sete, distributed over both sides and the tips (Ifig. 1). In the successive generations in the beginning of the summer of 1872, these furcal lobes were already smaller, with but 3 to 5 or 3 to 4 sete, the salt water then showing 14° Beaumé (Plate XX XIX, Figs. 2 and 3). In the same season of 1873 and at 18° B. the furcal lobes were still smaller, representing short conical knobs with but one, two, seldom three, setee (ig. 4). Toward the end of the summer of 1874, many individuals still possessed conical knobs or protuberances instead of farcal lobes, without or with but one seta on tip, but the majority of them were entirely destitute of furcal lobes and sete, as is the case in Artemia muehlhausentt with which these degraded examples were identical in their smaller size as well as in other characters (Figs. 5 anc 6). L also obtained the same results by domesticating Artemia salina in salt water of gradually increased density or concentration, the examples obtained being identical with those from the Kujalinker Lake at the end of the summer of 1874 (Ariemia muehlhausenit), yielding also the same transitory forms. By a reverse treatment, @. e., by gradually diluting the salt water, I succeeded with Artemia muchihausenti in producing already, after sev- eral weeks, a furca in the form of conical knobs, with one terminal bristle, by which treatment also the development of other parts of the body assumed a direction toward the higher specialized varieties of Artemia salina, this being at variance with the retrograde development taking place in condensing the salt water. It is remarkable that the gills of these animals enlarge in proportion or in ratio with the density of the water, so that in the form without fureal knobs (Artemia muehlhausenti) the surface of the gills is much larger in proportion to the size of the body than in Artemia salina. The gills of the former especially enlarge in width. I draw the inference that as the water of higher density contains less oxygen these Crusta- ceans adapt themselves by gradually enlarging the surface of the breathing apparatus. Concerning the gills, I have to state that they are elongate in Artemia salina and oval in A. muehlhausenti (Figs. 7 and 8). The width of the gills in A. salina average scarcely half of their length, in A. muwehl- hausenti two-thirds of their length. As regards the length of the body, I may mention the following measurements, showing the proportionate sizes of the gills; In Artemia salina the average length of the gills at a density of 10° B. is the one- twenty-first part of the body length, the width being the one-thirty-ninth part of the same. In Artemia muchlhausenii the average length of the 468 GEOLOGICAL SURVEY OF THE TERRITORIES. gills at a density of 24° B. is one-eighteenth part; their width is the one-twenty-eighth part of the body length. In measuring the Artemia salina the furcal lobes were not counted in, which would have made the difference still greater, considering the larger bulk of the body of Artemia salina compared with A. muehl- hausenti. It appears that the species (Arten) of the genus Artemia are liable to undergo, also, progressive developments at a gradually lessened density of the salt water. The nature of those salt-water pools yields the con- ditions necessary for their progressive growth, which pools, after a number of years by continued washing of the briny soil, may turn into fresh-water pools. Indeed, Artemia salina inhabits, also, such salt-water pools in the neighborhood of the lake in which occurs, at a low density of the water, also Branchipus spinosus Grube; at a still lower density, Branchipus ferow Grube, and another species of Branchipus with hook- hike bent furcal lobes, which latter species I described as Branchipus medius in the “Schriften der dritten Versammlung russischer Natur- forscher.” In artificially domesticating Artemia salina in gradually diluted salt water I obtained a form with the characters of the genus Branchipus, (B. Schaeffert) which might be regarded as a new species of Branchipus. I had already occasion to discuss this point in the “Schriften” of the Russian Naturalists, third session, and in the “Schriften” of the Neo- russian Society of Naturalists (Vol. II, part 2), and again have to state as follows: The only two characters separating the genus Branchipus from the genus Artemia are the following: Firstly, that Artemia, inclusive of the genital segment (two segments together), possesses eight apodous postabdominal segments, with the last of these eight segments nearly twice as long as the penultimate (Fig. 9c), while Branchipus has nine such segments, of which the neighboring segments, by twos, show but a small difference in length; and, secondly, the existence of a physiologi- cal difference, parthenogenesis occurring in Artemia, which phenomenon has not yet been observed in Branchipus. This is a negative and ill- defined character. The first mark of distinction seems to be more important, but under- goes changes in Artemia under the influences of the surroundings, where the character of the genus Branchipus appears especially, than when several generations of Artemia are domesticated in gradually diluted salt water. I have convinced myself, that the last long eighth segment of the post- abdomen of Artemia is homologous with the two last segments of the post- abdomen in Branchipus, namely the eighth and ninth. In the progressive growth of several generations of Artemia in gradu- ally diluted salt water the last apodous eighth postabdominal segment of Artemia subdivides itself into two segments, whereby nine apodous segments are formed (Higs. 10¢e and d), as in Branchipus. Branchipus, however, in its youth and towards the end of its Jast larval state, has but eight abdominal segments, of which the last is also as long as in Artemia. Also without artificial domestication we can convince our- selves of the homology of the last eighth apodous segment of Artemia with the same two last apodous segments of Branchipus. In the species of Branchipus occurring in this region we find fine bristles distributed around the posterior end of each postabdominal segment, except in the last ninth segment. Every bristle arises from the mid- dle of a complex of small tooth-like spines which are of extraordinary PACKARD. ] TRANSFORMATION OF ARTEMIA. 469 size in the male of Branchipus spinosus. Such bristles we also find in Artemia in the same places and similarly distributed (Fig. 9d), only that they do not arise out of a complex of dentate spines, but out of the middle of a complex of cuticular cells, which can searcely be distin- tinguished from the surrounding tissue (Fig. 11). It is of some importance that in Artemia not only near the end of each segment do we find such circularly placed bristles, but also in or a little above the middle of the last long eighth postabdominal segment, t. €., on that spot where the articulation ought to be, and where it is actually found in Branchipus, between the eighth and ninth segment, and where in Artemia this articulation after domestication of several gener- ations in salt water of successive lower density, 7. e., under such con- ditions, is formed, which may be serviceable to progressive develop- ment. Under the same conditions the complexes of cuticular cells just men- tioned transform; out of their midst bristles develop by degrees in both sexes of the domesticated Artemiz, into complexes of denticular spines, as they. are found in both sexes of Branchipus. (Fig. 12.) These denticular spines are small and of equal size in both sexes of Branchipus ferox ; 1a the female of B. spinosus they are also swak, but in the males of extraordinary size; in Branchipus medius (described else- where) they are large in both sexes, somewhat larger however in females than in males. At the same time, in domesticating Artemia, all other characters change progressively toward Branchipus; as, for instance, the length of the furcval lobes, the number of their bristles, and so forth. After such results we unwillingly arrive at the conclusion that the Artemia usually occurring in salt water of great density is nothing else than a degraded form of Branchipus under the influence of its surround- ings, which latter form usually inhabits fresh water or salt water of low density. On the other hand we have in Branchipus a higher developed form of Artemia, which has transformed in a progressive direction. The cause of this may not only be the different concentration of the water, but also its temperature. In nature Artemie mostly inhabiting salt lakes represent the summer forms, while Branchipus, often populat- ing dried-up pools, represents the spring or fall form. in domesticating, I observed that a high density of the water retains the growth and the development of specific characters of these animals, while a simultaneous higher temperature evokes sexual maturity earlier than the complete development of limbs; higher temperature together with higher density of the salt water also contribute to retrogradation of forms and their degeneration. Of course, as I convinced myself, a gradually increased density of the salt water, even at a lower temperature, tends to degradation of forms; for such a water, besides its mechanical influences upon the organism, contains less oxygen than less saline water and much less than fresh water, which plainly shows itself in artificially domesticating these animals, and which point I have already referred to. The following are the principal results of my investigations: 1. In artificial domestication of several successive generations. of Ar- temia salina Milne Edw. in salt water of gradually increased density we obtain a form identical with Artemia muehlhausenii M. Edw. 2. Artemia salina M. Edw. is also apt in a state of nature after a 1 See Plate II of the “Schriften” of the third meeting of Russian Naturalists, Zoo- logical Part. 470 GEOLOGICAL SURVEY OF THE TERRITORIES, small number of years, and a comparatively short series of generations, in a salt lake with increased density to transform itself into a form identical with Artemia muehlhausenti M. Kdw., whereby this form is ore to remain constant, as long as the surroundings are not changed. . Artemia is apt, in artificia ully domesticating several generations in ‘eal water of gradually decreased density, to progressively develop towards the genus Branchipus, obtaining thereby its generic characters, nine apodous segments. 4. In a state of nature salt-water ditches of different density, inhab- ited also by the higher specialized forms of Artemia, yield the condi- tions for progressive development of Artemia into Branchipus. 5. The size of the fureal lobes in Artemia, the number of bristles and their distribution on the tips and sides of the lobes, are, together with the other generic characters, depende.t on the concentration of the salt water inhabited by Artemia. 6. At a lower density of the salt water occur also in certain brine ditches Artemiv with pretty long furcal lobes, with a considerable num- ber of bristles (up to 22 distributed over each lobe), similar to Branchipus. 7. The only characteristic features distinguishing the genus Branchi- pus from the genus Ariemnia are: Firstly, the presence of cight apodous postabdominal segments, whereby the last eighth segment is nearly twice qs long as the preceding, while in Branchipus there are nine such apodous segments, of which neighboring segments, by twos, show but a trifling longitudinal differ- ence. Secondly, parthenogenesis occurs in Artemia, while in Branehipus it is not yet known to occur. 8. The last long eighth postabdominal segment of 4rtemic is homol- ogous with the last two postabdominal segments of BDranchipus. IT have now to append a few words on the parthenogenetic propaga- tion of our Artemia. I had already observed parthenogenesis in Artemia in 1871, while ar- tificially domesticating several isolated generations. It being something new to me at that time, 1 devoted mere attention to investigations on the influence of surroundings on Artemia relative to morphology. Of three isolated generations of 2 Artemia salina 1 obtained, while artificially domesticating them, by parthenogenetical propagation, in every density of the salt water that sustained their life, only females. . . . L[mentioned in the “Schriften” of the third meeting of Rus- sian naturalists at Kiew, . . . that the males appear in the lake in great numbers at a moderate density of the salt water. For such moderate density I took the density of the Hadschibei Lake in the summer of 1870, 1t having been literally filled with Artemic, whence they were thrown on the shores in piles by the waves, where they decayed. However, I committed a mistake, overlooking an error in the protocol of the third meeting at Kiew, having said in my printed report that only at a mean (moderate?) density of the water, similar to the density of the preceding year (1870), by domestication as well as during the summer in the lake males appear, instead of having said, only at a moderate density of the water, similar to that of the preceding year, by domesti- cation as well as during the summer in the lake the males ought to ap- pear. As I noticed at the time, that the males of Artemia appear in the lake at a certain density of the water, I assumed, after I could not ob- tain them either at a higher or lower density, that they still ought to make their appearance at the density for which I took the salt water in the PACKARD. ] TRANSFORMATION OF ARTEMIA. A471 summer of 1870, then not yet being aware that, according to Professor Siebold’s investigations, no males could be developed! The same error crept into an extract of the protocol, sessions of the zoclogical part of the third meeting of Russian naturalists at Kiew contained in this journal (Zeitsch. f. w. Zoologie), and this gave Professor von Siebold occasion for a timely remark.? Taking advantage of the present occasion to correct the mistake, observing that it was not printed in my paper, although the latter, together with the report, was prepared in the same session, I have yet to add that Artemia salina becomes accustomed to gradual changes in the concentration of salt water in the lake, as well as in do- mesticating them, and then becomes fitted to stand a very high or very low density of the water, so that either of them form a suitable envi- rofment. In rapidly changing the concentration of the salt water the same is rendered unfit to sustuin life, changing the manner of obtaining food, and produces, at the same time, in a state of nature, the appear- ance of males in forms to which parthenogenesis is peculiar. I had atready observed this in Artemia in the lake, but saw this es- pecially in Daphnia with artificial domestication of non-isolated females, that the males of the domesticated species first appear on the most ex- treme life-sustainable limits of the surrounding elements, 7. e., as well at a too low as at a too high temperature. If we domesticate the fresh-water species, Daphnia magna Leydig, in weak salt water, which they stand well, there appear, at this compara- tively rapid heightening of density of the salt water, males and fertil- ized eggs at such a moderate temperature, at which ordinarily the same species in fresh water propagates parthenogenctically. In the Hadschibei Lake occurs Daphnia rectirostris Leydig, at a den- sity of the salt water of 5° to 8° B., especially in spring and fall; the same disappearing in summer at a higher density of the salt lake, while before the females often in the middie of the summer cease to pro- pagate parthenogenetically, bearing as in fall fecundated eggs in ephippia. Altogether I produced during the artificial domestication of Daphnia the appearance of males and fecundated eggs through rapid augmenta- tion of the density of the salt water as well as through rapid increase of temperature. However it is difficult to say which will be the mean of concentration for a known species of Artemia, because a slightly less- ened density, though favorable for the growth of the individual, weakens its power of propagation, while a heightened density augments (or sup- ports) propagation, on the other hand this being a hindrance for the development of the individuals. The undiscovered mean of density, it seems to me, must be between these two points, the most extreme limits of the favorable condition of the surrounding elements being then out- side of those two points. On these limits we must find a density at which the males appear in the lake in great multitudes, as severel observations and analogous in- vestigations on Daphnia have demonstrated. I therefore recede from iny opinion that the males of Artemia appear at a mean density of the salt water, if the mean density is determined between that of favoring the development and that of assisting the pro- pagation. Until now I have found the greatest number of males of Artemia sa- lina in the Hadschibei Lake in the middle of the summer of 1870, at a 472 GEOLOGICAL SURVEY OF THE TERRITORIES. strong evaporation after continued drought, the salt water then rapidly reaching a high concentration. I have yet to add afew words on the geographical position of the lake and the salt-water ditches inhabited by Artemia salina. Two great salt lakes, the Hadschibei and the Kujalnitzky, are situated about 7 or 9 versts from Odessa towards Nikolajeff. These two lakes (Kussian, limane) were formerly two broad river entrances and ocean bays, into which two rivers formerly poured. At present these two small draining rivers no more deserve their names. The ‘limanes” were subsequently cut off from the sea by broad stretches of sand, the Peresippe, and were transformed into salt lakes. Only in the lower part of the Kujalniker-Limane, separated by an artificial embankment from the upper part for the purpose of obtainjng salt, is the salt deposited. The Hadschibei-Limane showed with my areometer 5° B. as the low- est and 12° B. as the highest concentration. The salt-water ditches: are distributed over the saline soil in ane neigh- borhood of the lake, situated between the lakes and the seashore along the Peresippe to near the city of Odessa. In the various ditches occurs salt water of various fecettics from nearly fresh water up to water of 5° Beaumé. Only the more salty ditches of 4° to 5° B. are inhabited by a (ziem- lich ausgebildet) developed form of Artemia salina, often associated with Branchipus spinosus. In less saline ditches occurs Branchipus ferox and Branchipus medius. Similar results, as regards the evolution of the form, I have also obtained from Daphnia, Cy clops, and Canthocamptus, and I promise to soon publish these investigations. REMARKS.—1. I have especially endeavored in the above writings to draw attention to the fact that in domesticating Artemia salina in gradually diluted salt water, after several generations and at a pro- gressive development, I obtained a form presenting the most important morphological characters of the genus Branchipus, so that such a form was at one time regarded by me as a new species of Branchipus. The principal generic characters of Branchipus I regard as the nine apodous postabdominal segments. Although we obtain in progressively domesticating Artemiw the characters of the genus Branchipus, and although, also, the other char- acters change in the direction toward Branchipus, such an artificially domesticated Artemia, for many reasons and marks of distinction, can only be considered as a lower form of a Branchipus, representing, con- sequently, a transitory form from Artemia toward Branchipus, aud an intermediate form between these two genera. Such a form can also be looked at as a prototype or radical type of these two genera. 2. An important circumstance is that in those Branchipus observed by me, a few bristles are distributed in a circle around each: post- abdominal segment just before the articulation, and that in Artemia such bristles occur also in a circle at a little above the middle of the last postabdominal segment. I mentioned above that in Branchipus each such bristle arises out of the middle of a complex of dentate spines, which are of very large size in the male of Branchipus spinosus. I find it necessary to add that I found such dentate spines in both sexes of the species of Branchipus examined by me only on the ventral side of the postabdominal segment just before the articulation, at which location they could be plainly seen. It is well known that in the male PACKARD. ] TRANSFORMATION OF ARTEMIA. 473 of Branchipus spinosus groups of dentate spines occur only on the ventral side of the postabdomen just before the articulation. In the same places fine bristles arise out of groups of circulatory cells in Artemic living in salt water of high density, which cells, by domes- tication of several generations of Artemia in gradually diluted salt water, transform into groups of small dentate spines. 3. Under the name of postabdomen I mean the last nine segments of the posterior section of the body, or all apodous segments which are frequently called postabdomen. Artemia has eight such segments. After all, it seems to me that not all apodous segments deserve either the term abdomen or postabdomen, since the first two segments, bearing the external genital organs, are more sharply defined or insected from the following segments, being also somewhat shorter and broader than the latter, having therefore more resemblance with the precediug limb-bearing segments. It appears to be more proper to add the two connate genital seg- ments to the preabdomen, calling postabdomen all the other apodous segments; this view concurring also with the developmental history. According to the latter view we have seven apodous segments in Branchipus and six in Artemia. D.—CONTRIBUTION TO A KNOWLEDGE OF THE INFLUENCE OF EXTERNAL CONDITIONS OF LIFE UPON TLE OR- GANIZATION OF ANIMALS. By WLADIMIR SCHMANKEWITSCH.! {Translated by Dr. C. F. Gissler.] I published in 1875 in the Russian language, in the Transactions of the Neo-Russian Society of Naturalists (Vol. III, 2d part), a paper under the title “‘Some Crustaceans of the salt and fresh waters, and their rela- tion to the surrounding elements.” ? After the further elaboration of the material, I shall publish the entire contents of my labors, at present submitting only the part which I re- gard as the more complete. I.—Some instances illustrating the influence of salt-lake surroundings upon the life and develupment of several crustaceans. 1 Zeitschrift fiir Wissenschaftliche Zoologie, XXIX, 429-494, 1877. 2 The contents of the paper are the following: Chapter I. The genus Cyclops (€. bicus- pidatus Cls. and C. odessanus n. sp.. C. brevicaudatus Cls., C. brericornis Cls., C. serrulatus Fischer. C. tenuiformis Cls., C. minutus Cls.). Enumeration of the species and races of this genus from the neighborhoou of Odessa. Diagnosis of the undescribed forms of Cyclops. The indication of forms necessary to compare the characters of the known species of this genus. General remarks on Cyclops brevicornis and C. brevicaudatus. Effect of the surrounding element upon the forms of Cyclops under artificial domesti- cation. Chapter II. Cletocamptus genus noyum (family of Harpactidée), Cl. strémii and Cl. retrogressus, and domestication of the latter in changed surroundings. Chap- ter III. Transfuga gen. novumn (fam. Harpactide), Tr. salinus n. sp., and Zr. lacustris n.sp. Chapter lV. The relations between marine forms and fresh-water forms in the family of Harpactide. Chapter V. The genus Daphnia. D. magna Leyd. varietas, D. rectirostris Leydig ( Moina reclirosiris Baird) of salt and fresh waters. Daphnia degenerata n. sp. and D. rudisn. sp., both marine forms. Chapter VI. The genera Artemia and Branchipus. Artemia salina Milne-Edwards. The gencrations of Artemia salina receiv- ing the characters of Art. Milhausenti. Branchipus ferox Chyzer varietas. Branchipus spinosus Milne-Edw. Branchipus medius mihi. The characters of the genera Artemia and Branchipns. The transformations of the branchial sacs and posterior gill-lobes in Artemia and Branchipus under the influence of the surroundings. ATA GEOLOGICAL SURVEY OF THE TERRITORIES. For the purpose of illustrating this, 1 have chosen Daphnia rectirostris Leydig (Moina rectirostris Baird) and Branchipus ferow Chyzer. Daphnia rectirostris occurs here in large numbers in fresh-water basins, brine ditches, and also in the Chadschibaisky Salt Lake. In the latter they occurred at a concentration of from five to eight degrees of Beaumé’s areometer. Two characters are seen in the Daphnia rectiros- tris living in so diversified elements, the former depending on the latter. It appears firstly, that in salt water, and especially in the more saline Chadschibai Lake the middle temperature is lower, #. e.. the temperature more favorable for the life of Daphnia rectirostris than the temperature favoring the life of the same Daphnia in fresh water, so that the Daph- nia, being in reality a summer form of the fresh waters, changes in salt water into a fall form, occurring till the beginning of winter in the salt lake at a concentration of 7° to S° Beaumé in immense quantities, even remaining viviparous at 2 temperature at which the individuals of the fresh-water generations of the same species could live no longer. Sec- ondly, the individuals of the salt-lake generations of Daphnia rectirostris represent a degraded or retrograde form of the fresh-water generations of the same species, differing from the latter the more the higher the concentration of the salt-water basins in which they occur increases, so that the individuals of the salt lake differ more from the fresh-water forms than the individuals living in salt ditches. So much do the forms of Daphnia rectirostris from the salt lake differ from these of the fresh waters that they could be regarded as a separate variety of Daphnia rectirostris, although it is but a transformed gener- ation retarded in its development, and changed under the influence of the su rroundings of Daphnia rectirostris inhabiting the fresh waters. On account of various observations and experiments, I presume that the peculiarities of the salt-lake form of Daphnia rectirostris are entirely dependent on the properties of the salt water which they inhabit. Daphnia rectirostris cannot stand in summer a density of the water of the salt lake of 6° B., while it lives in great quantities in the same salt lake at a density of 8° B. in the fall, toward the end of October and in November, being than viviparous, that is, at such a season in which the fresh-water form of our Daphnia has already ceased to live. This is not an extraordinary phenomenon, considering that a certain aeration of the water is unconditionally necessary to sustain the life of Daphnia rectirostris, and that it is unimportant by which means the aeration of the water is regulated. Agreeing with the physical law the less the aeration of the salt water, the higher its density becomes, which results that fresh water must contain more air than any salt water of the same temperature. It consequently follows that also in a salt water of certain concentration at a corresponding lower tem- perature the same quantity of air as in fresh water could be contained. It is obvious that the quantity of air in the water of the Chadschibai Lake toward the end of October and at a density of 8° B. could approxi- mately be the same as that in fresh water during the summer, and therefore the processes of nutrition in the organism of Daphnia rectiros- tris could in reality be as favorable in both the fresh and salt water. Though analogous in general, they differ singly from each other, as, for instance, by the higher pressure of the more dense water, which density again depends on the quantity of salt and the lower temperature of the water. Dependant on such differences between salt and fresh water are also partly some differences in the organization of the salt and fresh water forms of Daphnia rectirostris. In the females of the Chadschibai Lake, the penicilli or fascicles of PACKARD. ] TRANSFORMATION OF ARTEMIA. AT5 knobbed setz (Tast-borsten) are but little developed, being scarcely fifty times shorter than the antennz themselves, while in the females of the fresh water the same sensitive penicilli are moderately long, and only six times shorter than the entire antenna. In the males, the sen- sitive bacilli are also shorter than in those males inhabiting fresh water. The small hooks situated near the sensitive bacilli on the tips of the male antenne of fresh water are strongly curved with pointed tips, while in the males of the Chadschibai Lake those hooks are shorter, less curved, and with blunt tips. Of the two pointed pale sensory threads situated on geniculated protuberances of the first posterior third section of the male antenne, the posterior one is a little shorter than the anterior thread, the latter coming out a little more in front. These threads are in the males of Daphnia rectirostris of the Chadschi- bai Lake, not in a straight, but in a screw-like line. The distance between one thread and the other is considerable, which character in the fresh-water males is much less prominent. The fresh-water individ- uals of this species have in their earlier stages a period during which they resemble in this, as well as in other respects, the mature forms of the salt lake. Besides the differences observed in the antenne of the salt-water generations of Daphnia rectirostris, our attention is called to the num- ber of slender “ gefiederten,” or, better, finely toothed spines, which occur on the lateral surface of the postabdomen of Daphnia rectirostris, running laterally seriatim and nearly parallel with the direction of the rectum. Leydig! called them finely feathered spines, which I would have called triangular, laterally finely dentate plates. However this may be, we observe in our fresh-water forms of D. rectirostris on each side 11 to 13 of these spines or plates, only 7 to 9 in the salt-lake form, meaning here, aS a matter of course, mature individuals only. In younger specimens there are less spines than in the adults of the same surroundings, and therefore the young fresh-water forms have the same number of spincs at a certain age as the adult forms of the Chadschibai Lake, which demonstrates the retarded development of the latter. Furthermore, our fresh-water Daphniz (D. rectirostris) are nearly color- less, or of a slight yellowish color, while the same species in the salt lake are of a reddish color. The so-called winter eggs of the former have an ochreous or orange-colored yolk. Those of the latter are red throughout. The bristles in general are less aumerous in the salt-lake form of the Daphnia than in the fresh-water form, and the average size of body in the latter is also less than in the former, although the differ- ence is but slight. The generations of D. rectirostris inhabiting our salt ditches repre- sent in every respect a transitory form between the fresh-water form and the salt-lake form, which lake has a higher density of the salt water than the water in the salt ditches, where it fluctuates between 1° and 5° Beaumé. In domesticating Daphnia rectirostris I also convinced myself that the salt-lake form can also live at a lower concentration of the salt water, only requiring herein a higher temperature, than that fit for them in the very saline lake; that is, it wants a summer but no fall temperature. In this less concentrated salt water the degradation of individuals is considerably diminished with the generations, so that they finally resemble the individuals of this species from salt ditches, i. €., they approximate the fresh-water form. In so domesticating, 1 Naturgeschichte der Daphniden, Leipzig, 1860, p. 175, Tab. X, 76. 476 GEOLOGICAL SURVEY OF THE TERRITORIES. during a rather brief duration the sensory threads on the tips of the antenne become nearly three times longer than before the beginning of domestication. We now find in comparing the fresh-water generations with the salt- water generations of Daphnia rectirostris that the latter generations not only changed in consequence of the immediate effect of the surrounding elements, but also in consequence of retarded development under their influence; and, furthermore, that the sexual maturity shows itself earlier in the salt-water generations than the complete typical development of the body parts. The termination of the sensory antenne, the color of the body, the lesser pinnulation of the bristles in the salt-water genera- tions are principally dependent upon the immediate effect of the sur- rounding elements. The smaller number of the above-mentioned spines on the postabdomen principally depends upon the retarded develop- ment under the influence of changed surroundings. In the latter case the individuals commence, without awaiting the development of their body parts, to augment, and are in that state a complete animal form. Branchipus ferox attords a still more characteristic example of the in- fluence of the salt-lake element. Milne-Edwards,! whose words Grube? repeated in his diagnosis of this species, gives a brief description of Branchipus ferox from the neighborhood of Odessa. Chyzer?® completed his description from Hungarian specimens. The diagnosis by Chyzer of this species differs so much from that of Milne-Edwards that both authors could not possibly have had one and the same form of Branchi- pus, as we shall see later on. It is difficult to understand why Milne- Edwards does not mention the two so important characters of this species, which ought to rank with the principal characters which Chyzer enumerates. This is the conspicuous length of the egg-sac, and espe- cially the tact that the abdominal appendages or fureal lobes are bristled only on their inner edge. To this latter peculiarity Chyzer especially points out the characteristics of Branchipus ferox. It is evident that Milne-Edwards had a very closely allied form to that of Chyzer’s, since in the neighborhood of Odessa, wherefrom Milne-Edwards’s form came, generations of this species occur in salt, brackish, and fresh water, which, owing to their dependence of the density of the water basins, consider- ably differ in their characters. The generations inhabiting salt-water ditches of about 5° Beaumé differ as much from the individuals inhab- iting fresh water, especially the Hungarian forms described by Chyzer, as any Species will differ from another one. Had I not found all pos- sible transitory forms between fresh-water and salt-ditch forms, had I not convineed myself of the variability by domestication of this form, I should have regarded the salt-lake specimens as a new form. For some time I really took them for a variety of Branchipus ferox Chyzer. At present, and after so many convincing results, I can only condition- ally regard this form as a variety. To demonstrate how much the salt-lake generations of Branchipus Jerox (from the salt-water ditches) differ from the Hungarian fresh- water specimens, compare the following characters: The egg-sac of the salt-lake Branchipus jerox reaches in its length only to the beginning, or to the middle, of the fifth apodous segments, but as the following sixth, seventh and eighth segments are longer than the anterior seg- ments, the egg-sac reaches scarcely to the middle of the postabdomen, e 1H: stoire naturelle des Crustacées, III p. 369. 2Bemerkungen tiber die Phyllopoden, Archiv f. Naturg p. 142, 1853. 3Fauna Ungarns Crustaceen. Verhandl. der zoologisch-botanischen Gesellschaft in Wien, 1858, p. 516. PACKARD. ] TRANSFORMATION OF ARTEMIA. ATT counting in all apodous segments, while in the Hungarian forms the length of the egg-sac equals the whole postabdomen, excluding the ab- dominal appendages. Besides, in Branchipus ferox of the salt-water ditches the egg-sac is not spindle-shaped, only elongate, often entirely oval, 7. e., not only shorter, but also broader, as in the form diagnosed by Chyzer. In our salt-water ditch forms the furcal lobes average in length the eighth part of the body length, inclusive of the furcal lobes; in Chyzer’s Hungarian form, as shown by the measurements, the fureal lobes average the fourth and a half part of the whole body length in- cluding them, that is, they are much longer in the Hungarian form. The most important difference consists in that while in Branchipus ferox of our salt ditches the furcal lobes have both edges bristled, in the form described by Chyzer only the inner edges of the lobes are bristled. Lastly, our salt-water ditch form measures, inclusive of the abdominal lobes, seventeen to twenty-two millimeters, the Hungarian form twenty- nine to thirty-four millimeters. Our salt-water form approaches in all other respects the diagnosis of Chyzer, and does not disagree with the determinations of Milne-Edwards and Grube. Besides the difference between the specimens of our salt-lake-water and the Hungarian fresh-water forms of Branchipus ferox, we find, after strict examination of the matter, that the bristles of the furcal lobes in our Salt-water-ditch forms, only in young animals shortly before becom- ing sexually mature, commence at the base of the lobes in one height, and that on getting older the number of bristles is lessened along the exterior edge, and that in the adult, and especially in old individuals, the bristles on the exterior edge of the furcal lobes will be seen to com- mence more than twice lower than on the inner edge of the same. At ' a length of the furcal lobes of 2.5™™, in the adult form, the bristles be- gin on the inner edge at a distance of 0.24"™ from the base of each lobe, but on the exterior edge they begin at a distance of 0.52™™ from the base of each lobe. The bristles on the exterior edge of the lobes are in adults of this form more than twice shorter than those on the opposite inner edge, especially on the first half of the furcal lobes. The younger the individuals are the more trifling is the difference between the bristles of the inner and outer edge of the lobes. Yurthermore, in the salt-water ditches of low density such generations of Branchipus ferox live, whose individ- uals have an average size of about 22™, In these larger specimens the exterior edge of this or that abdominal appendage in the adult state has no bristles from base to the middle of the lobes. The bristles of the exterior edge are also shorter and more sparsely distributed than in the preceding form. Their egg-sac usually reaches down to the middle of the fifth apodous segment, and is a little longer than the egg- sac of the preceding form. The ditches with nearly fresh, scarcely saline-tasting, water harbor also still Jarger specimens of Branchipus Jerox, measuring some 25" in average length. In these large individ- uals in mature age the exterior edge of either furcal lobe is without bristles from base down to over the middle of each lobe. The remain- ing bristles are again still more sparsely placed, and also shorter than in the preceding form; the egg-sac is also a little longer. Specimens of Branchipus ferox, collected by me in ditches on Taman Island, in the neighborhood of the city of Kertsch, represent another link in the series of transitory forms between the extreme generations of the salt-lake and Hungarian fresh-water specimens. In the Taman specimens, which have a length of 30", the egg-sac reaches to the middle or to the end of the fifth apodous segment of the abdomen, the furcal lobes having nearly the same length as those of the Hungarian 478 GEOLOGICAL SURVEY OF THE TERRITORIES. specimens; but in the adult state, on their exterior terminus of the lobes, remain more or less short, sparsely placed bristles, the less the older the specimens are. As the smallest number of bristies, 1 found seven; so that at 6.97" length of a lobe its exterior margin was bristled only up to a distance of 1.5". As the highest number of bristles in mature specimens, I counted fifteen; so that at 6.87" length of a lobe its exterior margin was bristled up to a distance of 3.4™" from the tip of the lobe. To explain the formation of such a remarkable character as the miss- ing of bristles on the exterior margin of the furcal lobes in generations of Branchipus ferox inhabiting fresh-water ditches, we need only be reminded that these lobes are the longer the less dense the water is in which they live, and that in the real fresh-water generations of this species the furcal lobes are the largest. I have also observed that these lobes distend at a wide angle in swimming; the wider they distend the longer they are. In addition, the exterior margin of these lobes contin- ually cut the water, being therefore in a higher degree, subject to the mechanical influence of the water. Even if the pressure of the salt- water be higher then are the furcal lobes of the salt-water forms of this species much shorter, and, besides, we may say that the salt-lake gen- erations do not fully grow up; therefore, remaining provided with the principal characters of the young fresh-water forms. The fresh-water generations of Branchipus ferox have, amongst all European_species of Branchipus, the longest furcal lobes. The domestication ot several generations of this species in sait water of various concentration verifies also the effect of the surroundings. I therefore can see no necessity of admitting here an influence of nat- ural selection and to add new unknown factors to solve this problem. One of the most remarkable phenomena is the fact that in our shallow marine district so rich in salt-water basins (closed lakes and salt-water ditches), even in pure fresh water the typical fresh-water form of Bran- chipus ferox Chyzer does not occur, but only a form approximating in a certain degree those of the lowest generations of this species, inhabiting our salt-water ditches, connecting it with the Artemia; above all with the extreme race of Artemia salina (varietas a), which also lives in our salt-water ditches. This is not the only example of such an abberration of form. In the fresh waters of the neighborhood of Odessa we do not find the real Daphnia magna Leydig; however, one of its races occurs, representing an abberration toward Daphnia pulex Leydig! of a lower grade. The generations of our fresh-water Daphnia magna variety, distribute themselves also in a few salt ditches, where they form a still greater deviation from the typical form. In more saline ditches (ofabout 3° Beaumé) occur such forms of Daphnia, bearing the characters of another, simultaneously reminding one of Daphnia magna varietas, D. pulex, and partly also of Daphnia reticulata and D. quadrangulata Leydig. I described this form under the name of Daphnia degeneraia? Regarding it as a degraded form of those ancestors, which gave origin to the existence of Daphnia magna and D. pulex, I actually convinced niyself in examining generations of Daphnia degenerata at ditterent seasons of the year and at various densities of the salt water, and also, by domesticating them, that it is a changed and degraded form of our 1See my reports in the ‘‘Schriften” of the Neorussian Society of Naturalists, Vol. III, Part 2, pp. 196-216. 2 Opus citatum, pp. 228-232. I have to add the following: The sensory antenna of the female of D. degenerata i is provided on its upper surface with the same bristle as occurs in D. magna. PACKARD. ] TRANSFORMATION OF ARTEMIA. 479 variety of Daphnia magna, the latter variety being itself again an inter mediate form between the typical Daphnia magna and D. pulex. If we would restore the middle radical form, which gave origin to Daphnia magna and D. pulex, we would receive a form most similar to our Daph- nia magna varietas, in the production of a still farther allied, a prototype for the largest number of Daphniz, we would arrive at a form most similar to Daphnia degenerata from the salt-water ditches. Such ex- amples show that, owing to the neighborhood of salt waters in which the generations of the fresh-water species distribute themselves and in which they change under retardation of development, the species them- selves in fresh waters of such districts deviate to a certain degree jrom the typical form, 1. e., they change toward the direction of the next lowest species of their genus. In consequence of the existence of such an ele- ment in these districts the area of distribution of the species changes; but as the center of this area will be found somewhere between the fresh-water and the salt-lake e‘ement, the aberration of the fresh-water generations in the neighborhood of salt-lake waters, in which the gene- rations of the fresh-waters pecies already considerably changed them- selves and become retarded in their development, is easily understood. The salt ditches, which distribute themselves on saline soil near Odessa between the sea and the two salt lakes, the Chadschibaisky and the Ku- jalnitzky, become fresh-water ditches after gradual elevation, and sim- ultaneously begin to become populated with fresh-water generations, whereby these generations form, to a certain degree, changeable transi- tions toward the more changed salt-lake forms. Some of the ditches six years ago containing salt water of about 5° to 4° Beaumé, and inhabited by the salt-water species, Branchipus spinosus Milne Hdw., now contain nearly fresh water, and are populated this year (1876) with the fresh- water forms Daphnia magna Leydig varietas and Cyclops brevicaudatus Claus, slightly changed in the direction toward the lower forms. In re- lation to the latter, a transitory form of Cyclops brevicaudatus varietas b' and Cyclops brevicaudatus Claus, was to me of great interest. In the real fresh-water Cyclops brevicaudatus the extreme inner one of the four farcal bristles is twice as long as the extreme outer, or actually the twenty- fifth part shorter than the double length of the last outer bristle; in gener- ations inhabiting less saline ditches the extreme inner bristle is, on an average, the sixth part shorter than the double length of the extreme outer. In Cyclops brevicaudatus varictas b. the extreme inner furcal bristle is but little (one-quarter) longer than the extreme outer. The adult forms of the changed generations of Cyclops brevicaudatus in the less salty ditches exhibit nearly the same relution of body parts, as seen in the young, immature, pure fresh-water forms of the same species ; but the ma- ture individuals of said variety correspond in this point with the younger individuals of the species:= To this I have to refer also the interesting influence of the surround- ings upon the development of specimens of Artemia. The growth of the specimens of Artemia salina in salt water of high density and at the same temperature proceeds at least twice as slow as the growth of speci- mens of Branchipus ferox in less saline water. Abstractedly from the fact that the growth of specimens of Artemia salina requires much time, sexual maturity appears much earlier in proportion to the full de- velopment of body-paris, than in Branchipus. At a high concentration ‘Consult my paper in the “Schriiten” of the Neoruss. Soc. of Naturalists, vol. iii. part 2, pp. 32 to-36, and 74 to 77. Also on the domestication of Cyclopidi, ibiden, pp. 84 to 95. A8() GEOLOGICAL SURVEY OF THE TERRITORIES. of the salt water, only inhabitable by Artemia, and especially at suffi cient warmth, the mature sexual products show themselves already at a time when the provisional parts of the second, lower antennz were scarcely dropped, @. e., when they have not yet left the last larval stage. Artemia lives a much longer time in the larval state than Branchipus, indeed the longer, the higher the concentration of the water for Artemia and the lower for Branchipus. Between the fresh-water Branchipide and those Artemie which can still live in a salt-lake self-depositing salt, there is a relative great difference. Accordingly we must allow that we can produce, by corresponding domestication of generations of Arte- mice, already in their larval stage, but in any case in the last period of the latter, before the sécond antenne have dropped their provisional parts, sexual maturity. Carl Vogt’s observations have shown that the eyes appear much later in Artemia than in Branchipus,! and I presume that this is applicable to those Artemiz which are in relation to Bran- chipides, degraded forms of the latter. I have to mention the circumstance that the concentration of the salt water vigorously stimulates the multiplication of Artemia. The highest increase of a given species of Artemia is brought about by a density of the salt water which is a little higher than that generally assumed as the mean for this species; therefore under such conditions which hin- der, to a certain degree, the growth of the individuals and the develop- ment of their body-parts. On the other hand the most rapid growth and the progressive development of body- -parts happen to appear at such a concentration of the salt water, which is a little below the mean for a given species, and at which density the propagation of the indi- viduals decreases. In Artemia salina I observed the highest multipli- cation in a state of nature at a density of the salt water of 10° to 129° Beaumé’s areometer and with summer temperature; the highest devel- opments of bedy-parts I noted at 5° to 7° Beaumé, and at the same tem- perature. Between these limits must be the mean density of the salt water for our Artemia salina; I have also to remark, that the density of the salt water, together with the temperature, and independently of the same, influences the growth and the propagation of these animals. It appears that the parthenogenetic reproduction in Artemia does not only depend upon the temperature, as in Daphnia, but also upon the density of the salt water. I observed at least viviparous reproduction in Ar- temia salina in stronger saline water at such a low temperature at which viviparturition in the same species does not occur in less saline water, although it does not hinder viviparturition at a comparatively higher temperature. In all such cases the quantity of air contained in the water and dependent upon temperature, as well as upon concentration of the salt water, plays an important role, regulating many of the func- tions of life. Perhaps the variability of the concentration of the salt water yields, in Artemia, one of the main causes of parthenogenesis, the latter not ‘being yet known to occur in Branchipodide, inhabiting prin- cipally fresh water. Density and temperature of the salt water in their influence upon Artemia are combined in such a manner that, when the existence of an Artemia-like form in fresh water is possible, the same can only exist at a nearly summer and possibly high temperature. The lower the density of the salt water the higher a temperature is re- quired, if Artemia shall preserve its form at least in its principal char- acters. In this sense, Branchipus stagnalis, which, according to the 1**Revue scientifique de la France et de l’étrang.,” 2. series, 1873, No. 27, pp. 632 to 633. Also in ‘‘Meeting of Swiss Naturalists” in Freiburg i 1. 8., 1872. PACKARD.] TRANSFORMATION OF ARTEMIA. 481 statements of the authors (Leydig, Claus, Spangenberg) has eight apo- dous segments of the abdomen, represents in its principal characters an Artemia-like form; however, it remains to be determined whether this species is peculiar to Summer temperature, of which we have a few inti- mations. It seems that the dependence of the quantity of air in the salt water upon its density, beside the mechanical effect of such a water, forms one of the main factors of the sexual and specific characters of Artemia, whose forms are distributed according to the various densities of the salt water, as the species of a known genus are dispersed ac- cording to geographical latitudes, or also after their appearance at dif- ferent seasons (annual species). Moreover, a certain concentration of the salt water 1s, probably again in consequence of a certain quantity of air, in accordance with the physiological processes in Artemia. I here omit the respiration and the changing of the gill-saes of Artemia with the changing of the concentration of the salt water, simply men- tioning the circumstance, that we most rarely find males with those lowest degraded forms of our Artemia, bearing the characters of Arte- mia Milhausenit, living at the highest density for Artemia, and that, as we will see, the males of that race of Artemia salina (varietas b.) in salt ditches occur, which are most progressively developed and which live, in comparison with our other forms, at the lowest density of the salt water, as will be explained later on. IIl._—On THE GILL-SACS AND THE POSTERIOR BRANCHIAL LOBES IN ARTEMIA AND BRANCHIPUS. I shall speak in this section of the relation of these appendages in Artemia and Branchipus to their external life conditions. First we have to agree as to the determination of these parts. The gill-sac in these forms is called by C. Claus (in his paper on Branchipus stagnalis and Apus cancriformis) ‘‘ Kiemensaickchen”! (gill-sacklet). Grube calls it “unterer Branchialanhang”’ (lower branchial append- age). 8. Fischer called it “‘unterer Branchialsack” (lower branchial sac). The posterior branchial lobes are called by Claus (ibidem) “‘hinteres Branchialblatt” (posterior branchial leaf); by Grube, ‘“‘oberer Branch- ialanhang” (upper branchial appendage); by S. Fischer, “oberer Branch- ialsack” (upper branchial sac). The first which demands our attention is that the gill-sacs and poste- rior branchial lobes in Artemia and the salt-lake Branchipus enlarge in length and more so in width during the domestication of specimens, or still more of generations of these forms in salt water of increased density. Specimens of Artemia salina taken from the Chadschibai Lake, show- ing a density of 9° Eeaumé, I divided into two equal vessels, gradually diluting the salt water in one of them, but increasing the density of the salt water in the other. I kept the water in both vessels at equal height. In both vessels were old and young growing specimens. Both jars stood near to each other and were, with the exception of differently- concentrated water, as regards temperature and all other influences, under the same circumstances. The experiment lasted for four weeks, ‘during which time I daily measured the length and width of the gill- '“Abhandlungen der kéniglichen Gesellschait der Wissenschaften zu Géttingen,” vo]. xviii, 1873. san Bemerkungen iiber die Phyllopoden” in ‘‘Archiv fiir Naturgeschichte,” 1653, p. 3 Middendorf’s Sibirische Reise, St. Petersburg, 1851, vol. ii, part 1, p. 151. ol H 482 GEOLOGICAL SURVEY OF THE TERRITORIES. saes and the posterior branchial lobes of the domesticated mature speci- mens of both vessels, measuring also the length of the body, finding also the ratio between the length and width of these appendages to the length ~ of the body, inclusive of the furca. ‘The resulting figures gradually in- creased with the strength of concentration of the salt water in one or the other vessel in two different directions, the animals showing in the fourth week of domestication a very considerable difference, which plainly illustrated the increase of the length, and more so of the width, of said appendages at a heightened density of the salt water, and also the de- crease of those parts at a reduction of density of the water. Toward the end of the fourth week the salt water in both jars attained a difference of 10° Beaumé, the gradually-diluted salt water showing then 3° Beaumé; the salt water of gradually-increased density indicated 13° Beaumé. To compare the size of the gill-sacs and posterior branchial lobes of Ar- temia salina at decreasing and increasing density of the salt water, in measuring I searched for figures which indicated which part of the body- length the length and width of these or those appendages in these or those specimens formed. During the fourth week of the above-men- tioned period of domestication I obtained the following figures as aver- age results in two diverging directions: At a decreased density At an increased density of the salt water the gill-sacs yielded in length the 24, 3, . in length the 22, 4, in width the 46, 5 in width the 40, 6 part of the entire body-length; the posterior branchial lobes yielded in length the 17, 6, in length the 16, 8, in width the 38, 9 in width the 34, 9 part of the entire body-length. I have to remark that toward the end of the period of domestication the resulting figures in the measurements showed considerable oscilla- tions. The cause of it is that in salt water of extremely decreased or -extremely increased density the animals soon became so short-lived that the older individuals, as well as the younger just before or soon after becoming sexually mature, died. The relation of the body-parts in such young, though sexually mature individuals, resembles in some degree the relation of the body-parts in young immature individuals in another surrounding element, then normal for the species; for we observe also a slight retardation of growth in a suddenly produced ex- treme decrease of the density of the salt water the same as in the in- crease of the density of the salt water. In insufficiently gradually diluting the salt water the individuals of Artemia salina die, as it were, of debility, which cause lies probably in the heightened oxidation in the organism dependent on the increased quantity of air in diluted salt water. The highest development of the furca and the greatest number of its bristles are not incongruous with the lowest density of the salt water which this species can endure for a longer or shorter time, but it is congruous with a concentration not much lower than that peculiar to the species. The more gradual the concentration of the salt water ir the domestication of successive generations of Artemia salina is changed the more deviates the mean (for this species) favorable concentration from that concentration which is the mean for it in free nature. In comparing Artemia salina with those degraded forms and genera of this species exhibiting the characters of Artemia milhausenw, living PACKARD.] TRANSFORMATION OF ARTEMIA. 483 at a very great density of the salt water, approaching the natural deposition of salt, or having attained the latter already, we find a great difference in the size of the gill-sacs and the posterior branchial lobes, since the appendages mentioned are considerably larger in the latter than in Artemia salina. To see this, we compare specimens of Artemia salina from the Chadschibai Lake at 9° Beaumé in the first half of Sep- tember with the degraded genera of this species! taken from the Kujal- netzki salt lake at 24° Beaumé, also in the first half of September of the same year, that is, at very different density of the salt water and at nearly the same temperature. Hereby we receive in middle average, and omitting fractions, the following figures: In Artemia salina in Septem- In degraded specimens of Ar- ber at 9° Beaumé— temia salina with the char- . acter of Art. milhausenii at 24° Beaumé— the gill-saes yielded in length the 23, in length the 18, in width the 44 in width the 28 part of their body-length; the posterior branchial lobes yielded in length the 17, in length the 15, in width the 36, in width the 24 part of their body-length. The length of the body of Artemia salina was here taken together with the furcal lobes, exclusive of their terminal bristles, in the same manner as in the above stated experiment; the body-length of the specimens with the characters of A. milhausenti to the end of the abdo- men, as they have no abdominal furca. Since the furcal lobes form a part of the body of Artemia salina and partake of the nutrition like the other body-parts, I have not excluded them in my calculations, although, too, the relations without this furca, which is of inconsiderable length, in comparing the specimens of this or that species, scarcely vary. I also add that I took here, as well as in the above stated experiment, the gill- sacs and posterior branchial lobes of the eighth pair of legs, thouzh they are not the largest in this leg. These appendages in mature specimens increase in size from the first to the sixth pair of legs, on the following legs becoming somewhat smaller, without, however, there being much difference between the sixth and eighth pair of legs. The comparison in any case loses nothing, as the specimens have been compared after one and the same pair of legs. I took these appendages from the eighth pair of legs, coming nearer the mean figure, which would express their size in all pairs of legs. Not less different is also the form of the gill-sacs in the degraded generations with the character of Artemia milhausenit and in Artemia salina. For comparison it is better to take the gill-sacs from the mid- dle pair of legs, as they are of smaller size on the first two or three pairs of legs, and as if not fully developed, having a somewhat deviat- ing form in the last pair of legs, gradually broadening towards the end, becoming in Artemia salina, as well as in specimens with the characters of A. milhausenii, nearly uniformly rounded. In comparing the gill-sacs of the middle pairs of legs of Artemia salina and Art. milhausenii we see that these sacs in Artemia salina are of an elongated form and that 1Compare my report in the Zeitschrift f. wiss. Zoologie, 1875, vol. xxv, 1st supple- mental part. 484 GEOLOGICAL SURVEY OF THE TERRITORIES. the width of the sac nearly amounts to the halfof its length, while they have an oval form in Art. milhausenii, the width of the bag nearly amount- ing to two-thirds of its length.' In ‘long continued domestication in salt water of gradually increased density I obtained, after several successive generations of Artemia salina, speciinens in which the gill-sacs and posterior branchial lobes had the same form and size as those of the specimens with the characters of A. milhauseniti, out of the Kujalniker Lake at 24° Beaumé, and in which still other characters appeared peculiar to them in free nature. It is important that in young individuals of A. salina in a certain age the gill-sacs and posterior branchial lobes have nearly the same size and form as in the mature individuals, with the characters of Artemia milhausenit, with the difference that in young individuals directly after quitting their larval state, and even, also, until they liberate themselves from the provisional parts of the second antenne, the largest of these appendages are not on the sixth pair of legs as in the mature forms, but on the fourth pair. Under the same circumstances under which in mature specimens of Artemia salina the gill-sacs on the fourth pair of legs amount in their length to the twenty-eighth and in their width the fifty-sixth part of the whole body-length, the gill-sacs in the young specimens (in the above-mentioned age) of the same pair of legs measure the seventeenth part of the body-length in length and the twenty- seventh part in their width; but at the time at which in mature speci- mens (at low temperature) of A. salina each gill-sac measured, on the sixth pair of legs, in its length the twenty-fourth, in its width the forty- eighth part of the body-length, in young specimens of the above-men- tioned age each gill-sac of the same pair of legs measured in its length the nineteenth and in its width the thirtieth part of the entire body- length. In young individuals of Artemia satina of this age the gill-saes of the eighth pair of legs corresponded, together with the posterior branchial lobes, in form and size with the same appendages of the same pair of legs in the mature individuals, which have the characters of A. milhausenit, inhabiting most saline water (about 24° Beaumé). In any case, on the whole, these appendages are, in the young specimens of A. salina of the stated age, considerably larger than in mature speci- mens of the same species, being, also, as it must be in the course of de- velopment, larger on the anterior pair of legs to the sixth than on the following pairs. In the young individuals of the age stated the gill-sacs measure on the third, fourth, and sixth pairs of legs in their mean length together the eighteenth and in their middle width the twenty-ninth part of the whole body-length, but in mature specimens of this species and under the same conditions the gill-saes of the third, fourth, and sixth pairs of legs measure in their middle length together only the twenty. eighth and in their middle width the fifty-sixth part.of the body-length- From the fact that the gill-sacs and posterior branchial lobes of the young individuals of Artemia salina of the stated age correspond in form and size with the same appendages in the mature individuals bearing the characters of A. milhausenit, we can infer that the latter is a gener- ation of A. salina retarded in its development in consequence of the ap- pearance of sexual maturity before the full development of the parts of the body. However, such an inference would be but partially true. The individuals with the characters of A. milhausenii not only exhibit retarded development under the influence of their surroundings, but they are also the result of the demand of the same element—the result ‘Consult my report in Zeitschrift f. w. Zoologie, 1875, vol. xxv, Ist eae part, Tab. VI, figs. 7 and 8. PACKARD. | TRANSFORMATION OF ARTEMIA. 485 of the influence of the organism upon the surrounding element. The hightening of the density of the salt water is naturally accompanied by a decrease of aeration in such a water, but this decrease again must produce in Artemia an enlargement of the breathing surface, i. ¢., the surtace of the gill-sacs. Concerning the posterior branchial lobes, they (partly also the gill-sacs) have to enlarge themselves in water of high density as auxilliary organs of locomotion, perhaps they also serve as auxilliary organs in respiration, especially in Artemia, wherein the pos- terior branchial lobes are marked out for their greater tenderness, than generally in Branchipus, in which they often are margined with tooth- like spines or lttle-developed bristles, being, as it were, the beginning ot bristles and spines developed on the other branchipeds. According to Leydig’s view the gill-sacs of Artemia and Branchipus do not serve as special respiration organs; but the investigation of Claus! and Spangenberg? make it in the highest degree probable that the inference that the gill-sacs, but not the posterior branchial lobes, are not special respiration organs, is a proper one. Such a conclusion will also be made by the consideration of these appendages in their re- lation to the surrounding element, under which latter I not only mean the density of the salt water, but also the temperature; toward the latter the gill-sacs are especially sensitive in a high degree, as we shall see further on. From such a great sensibility of these appendages toward the sur- rounding element, we must assume that they have a considerable size in specimens with the characters of Artemia milhausenii, not only owing to retained growth of A. salina, whose younger specimens have larger appendages, but also in consequence of their accession, owing to aug- mentation of their mass, due to the surrounding element, owing to the high density of the salt water. The fact serves as a proof that, in com- paring young individuals of Art. milhausenit with individuals of Art. salina of the same age, we find the appendages in the former of con- siderably larger size. Only a much earlier state of growth of Art. salina relatively agrees with the later state of age of those individuals, bearing the characters of Art. milhausenti, inhabiting salt water of much higher density than Artemia salina. Beside the interesting changes occurring during the course of development of generations influenced in a known manner by the surrounding element, we here observe an accession and, as it were, an accumulation of mass in the known parts reacting upon the element and developing according to the demands of this element. I call this a direct influence of the surrounding element, and moreover such an influence, toward which the organism keeps active, and I dis- tinguish it from another likewise direct influence of the same element, toward which the organism, so to speak, passively submits. As an ex- ample of this latter influence, I mention the retrograde development of the abdominal furca of Art. salina in salt water of high density, whereby the furca becomes as if atrophied, and, indeed, independently of the sexual maturity in specimens, appearing earlier than the full develop- ment of the body-parts. That influence of the element upon which de- pends the change of form, owing to the changed point of appearance of sexual maturity, I call the immediate influence oft the surrounding element upon the organism. In Artemia, and also to some degree in 1 “Zur Kenntniss des Baues und der Entwicklung von Branchipus stagnalis und Apus cancriformis.” In the ‘‘Abhandlungen K. Ges. der Wissensch. zu Gottingen.” Vol. XVIII, 1873, p. 19. 2 “Zur Kenutniss von Branchipus stagnalis.” Zeitschrift f. w. Z., vol. xxv, 1st supplemental part, pp. 23 and 37, 486 GEOLOGICAL SURVEY OF THE TERRITORIES. other species of crustaceans examined by me, we can observe all these modifications of the influence of the surroundings upon the organism. The formation and full development of the gill-sacs and posterior branchial lobes depend in Artemia and Branchipus not only on the salt-quantity of the water, but also on its temperature; since by a low- ering of temperature the size of the gill-sacs decreases, by a heightening of the temperature they enlarge. Ido not possess sufficient measure- ments concerning the posterier branchial lobes by which I could attest with correct figures the change of these appendages by temperature, although I obtained unmistakeable results, according to which they, contrary to the gill-sacs, but in a less degree, enlarge by lowering the temperature. Putting temporarily the posterior branchial lobes aside, I shall treat of the gill-saes only. In measuring the gill-sacs in specimens of Artemia salina, gathered in the first half of September out of the Chadschibai Lake, I was sur- prised at the figures obtained by the relation of their size to the length of the body, deviating far from the figures received in measuring the summer-forms, although the density of the salt water in the lake was but little lessened. Later in the fall, the specimens of Art. salina collected out of the Kujalniker Lake, at a density of the salt water of 139 Beaumé, had even a little smaller gill-sacs than the specimens collected in sum- mer at 9° Beaumé, from the Chadschibai Lake. Subsequently, I di- vided the young and old specimens taken from the Kujalniker Lake at a density of 13° Beaumué into two sections and domesticated one section at an average temperature of 14° [Réaumur?] the other section at an average of temperature of 7°+ Réaumur. A considerable differ- ence showed itself after two weeks, those individuals living at a lower temperature, but kept by me at a uniform concentration in both jars, had their gill-saes, especially in width, considerably smaller. In indi- viduals Jiving in higher temperature, each gill-sac on the eighth pair of legs on the average amounted to the twenty-second part in length and the forty-second part in width of the whole body-length; in individuals living at a lower temperature the gill-sac of the same pair of legs gave the twenty-fifth in length and the fiftieth part in width of the body-length. It seems that temperature has upon the gill-sacs a more vigorous effect than the concentration of the salt water; on the other hand, the density of the salt water has a stronger influence on the posterior branchial lobes. ‘The circumstance is hereby illustrated, that in the first, red variety of A. salina (varietas a, description farther on), the gill-saes are smaller, but the posterior branchial lobes are larger than in A. salina. Not to mention so many figures, I point to the width of these append- ages, since in these forms they differ in length little from each other. In measuring the specimens of A. salina at a density of 13° Beaumé, and the specimens of the first, red variety at a density of 16° Beaumé, at one and the same (moderately low) temperature, I found that the width of the gill-sacs of the eighth pair of legs in A. salina was the thirteenth, but in the stated variety it was the forty-ninth part of the body length, and that in A. salina the width of the posterior branchial lobes was the thirty-fifth, but in the red variety it amounted to the thirty-second part of the whole body-length. In this manner, besides the fact that the specimens of this variety were collected at a higher density of salt water than the specimens of A. salina, their gill-sacs are nevertheless smaller than in the latter; but the posterior branchial lobes are larger in the variety than in its species, this corresponding already with the larger quantity of salt contained in the water. Such. PACKARD.] TRANSFORMATION OF ARTEMIA. 487 a phenomenon is only explicable by the fact, that in a state of nature, on the average, a lower temperature is, together with a higher density of the salt water than with A. salina, peculiar to the first variety of A. salina (varietas a). The gill-saes, as special organs of respiration, must become smaller by a lower temperature, whilst the posterior branchial lobes, as the auxiliary organs of locomotion, must enlarge by the greater density of the water dependant on the lower temperature and the higher con- centration. But since the density of the salt water depends more on its concentration than on temperature, it is obvious why, by domestica- tion of Artemia, we observe more changes in the posterior branchial lobes by the concentration of the salt water than by temperature. The first of these varieties of A. salina (varietas a.) corresponds amongst our forms of Branchipus mostly with the species Branchipus spinosus Milne-Edw., according to the relation of the gill-sac and posterior branchial lobes and some other characters, together with the element which it inhabits. Brunchipus spinosus is characterized among our forms of Branchipus in a similar manner as the first variety of A. salina, and A. salina by small gill-sacs and large posterior branchial lobes, only herein Branchipus spinosus is the difference in size of these append- ages considerably larger. Such a phenomenon also fully corresponds with that element which Branchipus spinosus among our salt-water forms of Branchipus principally inhabits. It lives, in comparison with our other Branchipus forms, in a lower temperature, but at a higher con- centration of the water. Especially in younger age and at a certain time the gill-sacs and posterior branchial lobes much resemble the ap- pendages of the mature specimens of the stated variety of A. salina (varietas a.), aud altogether in younger age of the specimens of Branch- ipus there is a certain period when their leg-appendages in measure- ments more approach the appendages of the mature forms of Artemia than the appendages of mature forms of the same species of Branchipus. For comparison we take mature individuals of Branchipus spinosus and young individuals of this species, some time after they quitted their larval state, when the section between the eighth and ninth apodous segments of the abdomen has scarcely just been formed, and the furca is still two or two and a half times shorter than the section consisting of the two last segments of the abdomen, and which is homologous with the last (eighth apodous) segment of the abdomen in Artemia. In the mature Branchipus spinosus the furca equals the section consisting of the last two apodous segments. We obtain the following proportions: In the old specimens of In the young specimens of Branch. spinosus— Branch. spinosus— the gill-sacs amounted in length the 40, in length the 24, in width the 118 in width the 61st part of the whole body-length; the posterior branchial lobes amounted in length the 19, in length the 16, in width the 37 in width the 28th part of the whole body-length. The first variety of A. salina (varietas a.) is in relation to this, especially concerning the gill-sacs, between the species A. salina and the young specimens of Branchipus spinosus. I only kept the figure of the measurement of varietas a. of A. salina at such a salt capacity 488 GEOLOGICAL SURVEY OF THE TERRITORIES. of the water, at which it (the variety a.) forms the transition to the cor- responding variety of A. milhausenii, that is, at 15°, 16°, and 18° con- ~ centration after Beaumé’s instrument. In concluding, it results that at such a concentration of the salt water, at which the above stated meas- urements of A. salina showed themselves, 7. ¢., at 9° Beaumé, and the temperature of the month of September, we must obtain the following figures for this race: The gill-saes The posterior branchial lobes must amount in their length _ the 25th, the 16, 5th, in their width the 52d the 34th part of the whole body-length. The variety Branchipus ferox, hereabouts living in salt water ditches, and to which is peculiar a lesser concentration of the salt water, how- ever at a higher temperature than that peculiar to the species Branchipus spinosus, yields the following figures, in relation to the gill-sacs and posterior branchial lobes: The gill-sacs The posterior branchial lobes amount in length to the 24th, the 20th, in width ) the 56th the 43d part of the whole body-length. The variety Branchipus ferox (from salt-water ditches) is, in its leg- appendages and according to the element which it inhabits, in propor- tion to Artemia salina as Branchipus spinosus is to varietas a.of A. salina. Especially those generations of A. salina which live in salt-water ditches of about 4° Beaumé, or the generations of the second variety of A. sa- lina (varietas b.) are in relation to gill-sacs and posterior branchial lobes and some other characters, also in the element in which they live nearer the salt-lake generations (from salt-water ditches) of Branchipus ferox (varietas). I must add here that the legs themselves are longer in Branchipus ferox var. and in A. salina than in Branchipus spinosus and in A. salina varietas a., and that only on this account the posterior branchial lobes of the forms of the one or the other category relative to length have no great differences. But the length of the legs corre- sponds with that temperature and with that concentration of the salt water which is peculiar to each of these furms.! Concerning Branchipus medius mihi, we can nevertheless recognize abstractedly from the point that it forms a too isolated species in its characters and in the relation-figures of its gill-sacs and posterior bran- chial lobes, the result of the effect of the element in which it is dis- tributed, as I have mentioned in the description of this species.’ The knowledge of the effect of the surrounding element upon the gill- sacs and the posterior branchial lobes in these animals is important because the differences of size between these appendages, according to authors (Milne-Edwards, S. Fischer, Grube), represent no important species-characters. It is here the place to add a few remarks which show how far the life of A. salina depends on the air-capacity (actually the oxygen of the 1Consult any paper in the ‘‘Schriften der Neurussischen Gesellschaft der Natur- forscher,” 1875, vol. iii, 2d part, pp. 297 to £00. 2Ibidem, pp. 305 to 313 PACKARD.] TRANSFORMATION OF ARTEMIA. 489 air) of the salt water. By changing the air-capacity of the salt water by a changed concentration of the water, we can at least explain a num- ber of interesting phenomena in the life of Artemia. 1. If we in certain limits dilute the salt water too much in domesti- cating Artemia, then the animals become, by the too much reduced con- centration of the salt water, transparent, attenuated, their intestinal canal empties and becomes translucent, the gill-sacs often blacken, and the animals will die at the bottom of the jar, as it were, of debility. Butif we in time notice at the excessive dilution of the salt water the sickness of the animals, and if we, instead of augmenting the concentration of the salt water, heighten its temperature a few degrees, the diseased animals will become animated, the intestinal canal fills itself, the mo- tions become more rapid, the animals leave the bottom of the jar, doing well in such diluted salt water at a corresponding higher temperature. It seems tome that such a temperature supplants the superfluous air of the diluted salt water, which in the organism of the animals produced a too great oxidation, leading to weakness, during which the nutritive sub- stances could not replace the consumption. If by too strongly diluting the salt water the Artemia is consumptive, on account of want of nour- ishment, owing to the dying off of those microscopic organisms on which Artemia lives, these animals would not have revived so soon after a cor- responding increase of temperature. Moreover, microscopic organisms appear in the diluted salt water in great number, even Infusoria, while Joly! observed that Artemiz are omnivorous, and that they principally live on the lowest organisms of the vegetable kingdom peculiar to the salt lakes, such as various forms of Chlamidomonas, zoospores of Clado- phora, &c. 2. If we, in domesticating Artemia, excessively increase the concentra- tion of the salt water and not sufficiently gradually, its alimentary canal becomes solidly constipated, the animals keep nearer the surface of the water and die there, especially during exuviation, which is hereby just as difficult to overcome as in too much diluted salt water. However, if we in time in this case lower the temperature, instead of diluting the salt water, the animals, even at a too high concentration of the salt water, revive, doing well in such a water with, to a certain degree, low- ered temperature. It seems to me that in this case such a combination of high concentration and temperature is formed. bearing to the equi- librium of aération in the water, i. e., the quantity of air in the salt water is lessened by the increase of its concentration for just so much, as it is, according to physical laws, heightened by lowering the temperature. A - want of nourishment in very saline water is here out of question, since such a water is inhabited by immense numbers of simple organisms, and even at a concentration, allowing self-deposit of salt, great quanti- ties of a red Monad occur, whichis known under the name of Monas dunalit Joly (Diselmis dunalii Dujardin=Chlamidomonas dunalit Raben- horst). 3. If we gather out of a salt lake the adult Artemizx, together with their larve, and dilute the salt water to excess, then the larve will soon expire, while the adult individuals long after resist the dilution of the salt water. It appears that the larve of Artemia die faster in too strongly diluted salt water, because the small stock of material in the organism is not sufficient toward the intense oxydation in consequence of an excess of oxygen in such a water. 4, In a broad jar and at alow surface of water these animals also 1Joly, Sur ’Artemia salina, Annales des sciences naturelles, vol. xiii, Zoologie, pp. 246 and 255. 490 GEOLOGICAL SURVEY OF THE TERRITORIES. prosper in such non-diluted salt water, which was taken from the salt lake at a middle concentration peculiar for this species (Artemia salina), but they do not prosper so well in a narrower jar with higher water-sur- face, as they soon die in such a water. In the same narrow vessel and at the same high water-level these animals will still prosper if the salt water is proportionally diluted. In this latter case the animals are so - circumstanced, as in more saline water in the broader jar.with lower water-level. The diluted water contains more air, it being more pene- trable and better adapted for gas exchanges. 5. Accepting the fact that the water in a salt lake at a given time shows 10° Beaumé, and that it is populated with crustaceans of the genus Artemia, if we now take two equal vessels, placing in one of them water of this salt lake and a certain number of specimens of one genus of these crustaceans, and placing in the other jar specimens of the same animals out of the same salt lake, diluting the salt water to 7° or 6° Beaumé, a large number of animals will die in the first vessel under the same conditions, while keeping up the initial concentration of the water, but in the second vessel the majority of the animals will remain alive. In the second ease, that quantity of air is as if restored, which is wanting in the first, apparently by the influence of the vessel itself, as the water in the vessel is under different conditions from that in the salt lake. ‘This is all the more so the case with a summer-like tempera- ture. 6. The animals prosper also in a non-diluted ‘salt water better at a temperature lowered to a certain degree than at a higher temperature, yet they do much better in diluted salt water, when the concentration of the salt water has not been reduced above a certain degree. 7. Finally, the enlargement of the surface of the gill-sacs in Artemia with the increase of concentration of the salt water proves, as mentioned already above, apparently the dependence of Artemia in this relation principally on the reduction of air-capacity of such a water, even if the gill-sacs, accordiug to their location and formation, as it were, in these animals represent modified organs of locomotion. It remains for the physicists to determine how considerable is the solubility (the coefficient of assumption or of capacity) of the oxygen of the air in salt water when the variation of its concentration varies. In relation to this I can find no accurate data. II].—THE GENERA ARTEMIA AND BRANCHIPUS, AND THE RELATION OF SOME OF THEIR SPECIES TO THE SURROUNDING ELEMENTS. In the whole order of Phyllopoda the species of the genera Artemia and Branchipus are apparently those which are most sensitive to the influence of the surrounding element, in such a sense that a modifica- tion of the surrounding element is capable of producing in their genera- tions in a pretty short time visible mutations in their forms. A change of the surrounding element can even in one and the same generation produce such a variation of some parts of the body that it is difficult, in a State of nature, to immediately distinguish those forms which are most closely allied to each other. The species of these genera have been found by me mostly in salt lakes and salt ditches (Artemia exclu- sively), whereby they distribute themselves in such a manner that each species is peculiar to a certain concentration, and the change of this con-: centration in artificially domesticating their generations produces a change of form in the direction towards the next species or race which lives in another concentration of salt water, toward which side the PACKARD.] TRANSFORMATION OF ARTEMIA. A91 change of concentration in the artificial domestication yielded. The temperature hereby co-operates with the concentration of the water. Relating to this, the forms of the genus Artemia deserve special atten- tion. 1.—Artemia salina Milne-Edwards. This species occurs here in the closed Chadschibai and Kujalnitzki Lake and in the salt-water ditches. It sustains a fluctuation easily noted in the variation of body-parts, and in its growth at a fluctuation of the concentration of the salt water from 5° to 12° Beaumé, in which limits it was found by mein the water basins. Ataconcentration of the salt water which is higher than 12° (and still more than 15°) Beaumé, our Artemia salina commences in its generations to exhibit transitory forms towards Artemia milhausenit Milne-Edw., the latter living by a far greater concentration of the salt water than Artemia salina, that is, at self-deposition of salt or not far from it, 7. ¢., at 24° and 25° Beaumé, To the description of Artemia salina given by the authors we have to say, that the representation of characters of this species, as altogether of the whole genus Artemia in the present. time, is very inexact and vague. Firstly, we find mentioned that Artemia possesses but six terminal segments, while there are eight, since we have to count also these two first apodous segments of the posterior part of the body, on which, in the species of Artemia-genera, the external genitals occur. Grube,! in making of Artemia a section or a sub-genus of the genus Branchipus, repeats the mistake of his predecessors, saying, in the dia- gnosis of the group Artemia “‘segmentis apodibus sex.” Only in Artemia milhausenti, which lives at avery high concentration of the salt water, are the articulations between the segments, especially between the more pos- terior ones, Some what less distinct; but we can nevertheless, at least in specimens bearing the characters of this species from our districts (also from the Krimea), always distinguish them, especially in fresh material which has not. been preserved in weak alcohol for along time. In the lat- ter case, even in Artemia salina, only with difficulty can we see the articu- lations of the abdomen. If in any region Artemia milhausenti occurs with connate, apodous segments, be it in some or all specimens, then it is very likely that we, even in such an Artemia, cannot count six apo- dous segments. Secondly, it has been considered hitherto as the prin- cipal characters of the genus Artemia, that in the species of this genus the abdomen ends with a short furca, whose branches are bristles only on the end, and such a diagnosis of the genus Artemia we discover even in the very latest zoological hand-book. Grube’ repeats in the diagnosis of his group Artemia in the genus Branchipus the characteristics of the genus Artemia of his predecessors, in saying: Appendicibus caudalibus brevibus, apice tantum .setosis aut nullis. Our Artemia and two of its varieties, which I shall mention later on, have the bristles not only on the end but also on the sides of the furcal lobes, just as in the species of Branchipus, which usually only have more bristles. Besides the Arte- mia salina from the district of Odessa I have the same distribution of bristles on the furca in specimens of this species brought from the neigh- borhood of Astrachan and the Krimea. We have here dry years with @ hot summer where the concentration of the salt water in the Chad- schibai Lake is too high for Artemia salina. Then many specimens of this species have, especially in summer, bristles only on the end of the 1“‘Bemerkungen iiber die Phyllopoden” in “Archiv fiir Naturgeschichte,” 1853, p. 139. 2 Opus citatum, ibidem. 492 GEOLOGICAL SURVEY OF THE TERRITORIES. furca, the furca being at the same time shorter and less bristled, as un- der opposite physical conditions. If we compare the descriptions and — illustrations of Artemia salina of the various authors, we find that they agree less among themselves than they do compiled from specimens of Artemia salina, or taken from the descriptions of specimens gathered under various physical conditions, that is, at various concentrations in ‘combination with temperature. Milne-Edwards! says: That on each furcal lobe in Artenvia salina occur three or four bristles, while Grube? states, in his diagnosis, that 5 to 8 bristles occur on each furcal lobe. We find in Artemia salina from our district, under various behavior of the surroundings, on each lobe of the furca 4 to 12 bristles, seldom more. In the third form, living in salt ditches in the neighborhood of Odessa and the Krimea, we find 12 to 22 bristles on each lobe of the pretty- well developed furea. I take the latter form to be another variety or race of Artemia salina, though it obviously originated from generations of this species with progressive development under the influence of salt- water ditches, having a lower saline capacity than the salt lakes, popa- lated with Artemia salina. In those cases, where in our Artemia are more than five or six bristles on each lobe of the furca, the bristles are distributed not only near the end but also on the sides of the fureal lobes. The specimens of Artemia from the very saline Kujalnitzki Lake, having but three, two, one bristles on the end of the furcal lobes, or lacking them altogether, in the latter case having a very slightly de- veloped furea, with the other parts moditied ; those I take to be tran- sitory forms between Art. milhausenii and Art. salina; altogether the distribution of bristles on the furca, the number of bristles, and the shortness of the furca itself can not serve as an important distinctive character between the genera Artemia and Branchipus, and much less SO as a point of distinction between the species of Artemiz. In Artemia salina, as one of the most constant points of distinction, we observe the termination of the superior antenné or antenne of the first pair. The upper antenna here terminates with two protuberances or papille of the form of a truncated cone, one of which is somewhat stouter than the other. At the terminus of the stouter, broader cone, we notice three moderately short spines, only one of which can be seen on the terminus of the thinner cone. Each spine is a li tle curved, having at its base a quadrate, yellowish, light-refracting body. These four spines are the olfactory bristles of these animals. Immediately under the terminus of the upper antenna, near the end of its upper surface, arise three moderately long and usually curved bristles. Beside the mentioned terminations of the upper antenne we have to complete the description of Artemia salina by the following characters. In Artemia the posterior part of the body consists of eight apodous seg- ments, the first two of which bear the external genital organs, but the last eighth segment is twice as long as the preceding, being homo- logous to the two last apodous segments of the Branchipodes. The furca in Artemia salina is of very variable length. In our Odessa A. salina the furea is on the average six times shorter than the prolonged last abdominal segment. . The bristles of the furea are also of very variable number. We notice in our Artemia salina on each lobe of the fureca from four to twelve bristles, which are not only near the end of the lobes, but for the greater part distributed along their sides, at least if there are more than four or six bristles on each lobe. Toward autumn at a lowering of temperature and dilution of the salt water of the Chad- 1 Histoire naturelle des crustacées, Vol. III, p. 370. 2¢¢ Bemerkunken tiber die Phyllopoden,” Arch. f. Nat. 1853, p. 144. a eee Se wee ae ee ee EE eh ox re ee Foy Pires meek eo Sie oa nn pen ee PACKARD.] ' TRANSFORMATION OF ARTEMIA. 493 schibai Lake by rain, the furca becomes in the late generations longer and the number of bristles greater, since under these conditions the growth of Artemia salina is less retained and the sexual maturity ap- pears not so early, that is, not earlier than the complete development of the body-parts, which, however, is not so well defined in this species, being, as it were, but a relative matter. Also the termination of the upper antenne, being the most constant character of this species, modi- fies to a certain degree. For instance, I found in the autumn of one year, at low temperature and dilated salt water of the Chadschibai Lake, in many individuals of A. salina near the end of the upper an- tenne five olfactory bristles, instead ofthe normal number of four. In domesticated generations of this species in gradually diluted salt water we perceive also five olfactory bristles on the upper antenne. With the distinctive characters of A. salina we have also to include the form of the gill-sacs. They are in A. salina of an elongate form, their width being on the average twice less than their length. This character dis- tinguishes A. salina from A. milhausenii, in which the gill-saes are of oval or more rounded form, being on the average two-thirds as wide as long. As another important point of distinction of A. salina from the nearest allied races, [ mention the proportional size of the posterior part of the body constituting the apodous segments; the anterior part from the beginning of the head to the end of the last leg-bearing segment, i. ¢., to the beginning of the first apodous segment and the posterior part of the body, from the beginning of the first apodous segment to the end of the last seement before the beginning of the furca. The furca does not come into account, as its length is variable, being for instance in A. milhausenii, with which the other forms must relatively also be com- pared, entirely missing. We find that in A. salina the anterior part of the body is somewhat shorter than the posterior; proportionate to it as five to six oras five toseven. This relation of the parts also depends upon the concentration of the salt water in which these generations live. In reduced concentration the posterior part has an inferior size than in the higher concentration. Altogether the postabdomen of A. salina becomes longer and more slender with increased concentration. In many of our specimens with the character of A. milhausenit, which live at self-deposition of salt or nearly so, the anterior part of the body is twice shorter then the posterior part. To the most variable characters of A. salina we must reckon that reddish layer which lines the anterior part of the alimentary canal in the shape of a tube, which layer Joly' calls the liver, and Leydig? the stomach, as he separates it from the following part, the alimentary canal to the anal orifice. For better distinction I shall call the anterior part the stomach part of the tract, the second, the posterior part. The stomach part of the tract terminates in Artemia about in the middle of the seventh apodous segment, but the length of this part depends upon . the concentration of the salt water inhabited by the generations of this species, and partly also from the growth (age) of the specimens. At high salt eapacity of the water this part of the tract does not reach to the end of the sixth apodous segment of the abdomen; at lower salt 1 “Sur ’Artemia salina” in Annales des Sciences nat. 1840, pp. 238 to 239. 2¥. Leydig, ‘‘Ueber Artemia salina und Branchipus stagnalis,” Zeitschrift f. w. Z. 1851, pp. 283 to 204. 3 The first part of the tract Claus calls ‘‘ Magendarm,” the second part, the “ End- Darm” in his ‘‘Zur Kenntniss des Baues und der Entwicklung von Branchipus stag- nalis und Apus cancriformis,” 1. c., as above. 494 GEOLOGICAL SURVEY OF THE TERRITORIES. capacity of the water, but especially in autumn, it exceeds by far the beginning of the eighth abdominal segment. Likewise this part is longer in old individuals than in young, otherwise sexually mature speci- — mens. If we examine, relative to this, specimens on the extreme concen- tration-limits of the salt water, we find a great difference amongst them. In A. milhausenii the stomach part of the tract scarcely reaches to the beginning of the sixth apodous segment, but in our species of Branchi- pus this part terminates not far from the anal orifice. Finally, we must mention as a character of our A. salina the following: The claspers, or the lower antennez in the males, are much broadened on their second joint, having such a form as the male claspers of A. ari- etina, according to a drawing of 8S. Fischer.! On the anterior part of the male claspers, between the head and the protuberances, serving to clasp the female with, near the bent-down margin, there are two groups of ten-pin-shaped teeth or spines, in one group on each side. It appears that these denticulate groups corre- spond as rudiments of the well-known appendages, occurring on the claspers of many species of Branchipus, as for instance in Branchipus spinosus. Such bundles of teeth or spines occur also in that form of Artemia examined by Ulianin from Sebastopolis, and which was re- garded by him asa race of Branchipus arietinus Grube (= variety of Avt. artetina Fischer). Artemia salina Milne-Edw. varietas a.—This form, called by me Arte- mia salina var. a., approaches the species Artemia salina so much that, beside its larger size, no other distinct characters exist by which we, with the general variability of so many characteristic points of the Artemiz of this species, could distinguish ‘the same. However, if we have speci- mens before our eyes of this or that form, we must confess that we have to do with forms differing so much that we even could regard them as different species of the genus Artemia. A view of profound truth has been expressed already in 1871, by Professor C. Th. von Siebold, on the comparison of descriptions of "Ar- temia salina ot various authors. Siebold says:? ‘“¢*In comparing the vari- ous descriptions and illustrations given of Artemia salina, we become convinced that probably with this species-name entirely different species or races were marked out, and therefore a revision of the species of the genus Artemia by carcinologists would be recommendable, though this, however, would necessitate a comparison of vast material, especially as the hitherto insufficient diagnoses of the species of Artemiz, without reference to the characteristic formation of the male heads, have been _ compiled.” Further on Professor Siebold, in perusing the descriptions of the second antenne of the males in Artemia salina and that of the postabdomen of this species, foresaw what is now actually corrobo- rated. I find two principal races of Artemia salina, one of which is of smaller size, the Artemia salina, but the other is Artemia salina varietas _a., and there are, besides, still other changes of its generations depend- ing on various concentrations of the salt water, including also those degraded and modified generations of the two races of Artemia salina, which are, as I suppose, recorded in zoological literature under the name of the species of Artemia milhausenii. The main distinctions of the variety a. of the species Art. salina forms another mean length of it. Accepting as the mean length of Artemia salina six lines, we must accept eight lines of French foot for 1Middendorf’s sibirische Reise. St. Petersburg, 1851, Vol. II, Ist part. Table VII, fig. 32. 2“ Beitrige zur Parthenogenesis der Arthropoden.” Leipzig, 1871, p. 203. PACKARD. ] TRANSFORMATION OF ARTEMIA. 495 ’ the mean length of Artemia salina var. a. As a rule the specimens of this variety are two lines or nearly so larger than the specimens of the species.! With the mean size as a point of distinction, the fact may serve to show that the posterior part of the body in this variety from the begin- ning of the first apodous segment to the end is somewhat longer than in the normal species. The anterior part of the body in Artemia salina is in proportion to the posterior part in most cases as 5 to 6 (or 5 to7 in higher concentration of the water), but in this variety usually as 5 to 8, slightly fluctuating to this or that side in different salt capacity of the water. The postabdomen in this variety is not only longer, but also slenderer than in the normal species. The furea is longer in the variety than in the species, and the number of bristles on the furca is also greater in the variety. If the furca in the species is six times shorter than the last prolonged segment of the ab- domen, then it is but four times shorter than that segment in the race. But we also meet with specimens of the species with such a proportion of the furca to the last segment, as in this variety, and again we see tureal lobes in specimens of the variety with the same proportion to the last segment as in the normal] species. In Artemia salina occur from 4 to 12 bristles on each lobe of the furca, rarely more; in the variety a. of Artemia salina there are from 8 to 15, but seldom more. In this race, a8 well as in the species, we find however also less than four bristles on each furcal lobe; there occur three, two, and one bristle on each lobe, especially in more concentrated water; but such specimens and generations must, by modifications of other structures, be regarded as transitory forms between Art. salina and A. milhausenii. The claspers or second antenne of the males of the variety are less broad than in the males of the normal species. The groups of spines or teeth on the anterior part of the claspers, near their base, are some- what better developed in the males of the variety than in the males of the species A. salina. The second antenne of the females of this race are a little smaller and narrower than in the normal species, just as the mnale claspers are narrower than in the species. The specimens of the variety a. of Artemia salina are of a far darker red color than the specimens of the species, although there occur also specimens with the same color amongst the latter. The variety a. of A. salina is usually of a red color, and is found here in the Kujalnitzki salt lake, but Art. salina is usually of a grayish or reddish-gray color, occurring principally in the Chadschibai salt lake, in which occur also specimens of red color,’ which represent, as it were, the points of aber- ration of the species toward its race (var. a.). In the variety a. of Artemia salina the gill-sacs are a little smaller; the posterior branchial lobes, on the other hand, a little larger than in the normal species. According to the other structures, it does not differ from the species Artemia salina; and all that was said relative to the influence of the surrounding element about the species refers also to the variety a. of A. salina. All the characters of this variety correspond with the circumstance that specimens of them, in comparison with the specimens of the spe- cies, prosper better at a higher concentration of salt water, but at a lower temperature. , 1 The specimens of the species are about 14™™ length, the specimens of this variety 17 or 18™™, The summer generations are in one, as well as in the other form, a little smaller than the fall generations. 2The Kujalnitzki Lake has more saline water than the Chadschibai Lake. 496 ‘GEOLOGICAL SURVEY OF THE TERRITORIES. Important for my purposes is the following remark of Dr. Nitsche concerning Branchipus Grubit (von Dybowski) from the neighborhood of Leipzig: ‘Further on it exhibited the remarkable circumstance that two races of this species occurred: a larger one about 20 to 22™™ long and a smaller one about 15™™long. These lived in various ditches, and those inhabited by the larger race contained far less specimens than those inhabited by the smaller race.”!. The existence of two races of different sizes of Branchipus Grubti and the circumstance that the specimens of these races lived in different ditches is of importance. It would be interesting to learn? whether this ‘‘ratio quantitatis” between two races occurs at any time of the year (which I do not accept). In- formation about this latter point would especially be of value, whether the specimens of these two races occurred together in one and the same ditch. Artemia salina Milne-Edw. varietas b., like variety a., in reference to the species, represents, so to speak, another branch of the middle radi- cal form, from which it, together with the normal species, originated in the distribution of generations i in a modified element; this second variety (var. b.) represents in its distribution in an element of lesser concen- tration of the salt water the progressively developed generations of the species itself. Variety b. occurs in salt ditches near Odessa and Sebastopolis. In salt ditches near Odessa I found it at a concentration of 4° Beaumé, while at the same time in the other salt ditches of higher concentration specimens of A. salina occurred. The length of the specimens of variety b. scarcely differs from the length of specimens of the normal species; its postabdomen, however, is shorter and stouter than in the species; the furca is by far longer and more bristled than in the normal species. The postabdomen (exclusive of the fureca) is in this race also a little shorter than the anterior part of the body, at least in the young, though sexually mature specimens, while the same somewhat elongates with age. As the posterior part of the body elongates with the gtowth of the specimens to mature and old age, and likewise in heightening the concentration of the salt water, we can presume that it is in A. salina var. b. either shorter than the ante- rior part, or equals it, or is scarcely longer than the same, while in the species A. salina the posterior part of the body is considerably longer than the anterior.2 Only in the young specimens of the species itself, some time before becoming sexually mature, the posterior part of the body is still shorter than the anterior. In any case, such a character cannot sharply demarcate this variety from thenormal species. There are other characters by which we can distinguish them. The furca of the variety b. does not show any simple conical protuberances at the end of the abdomen like two prolongations of the same, but real—even if not segmented from the end of the abdomen, but only by a transverse, easily noticed ring, separated at the sides from its base—divided furcal lobes. They are rather large and more developed than in other forms of Artemiz. They have the shape of. lancet-like plates, tapering 1H. Nitsche: ‘‘Ueber die Geschlechtsorgane von Branchipus Grubii (von Dyb.).” Zeitschrift, f. w. Z., vol. xxv, p. 231. 2 From Dr. Nitsche we cannot expect to hear all the singularities referred to the race of Branchipus Grubei. Especially inquiring into the structures of the sexual organs of Branch. Grubii, which formed the topic of his dissertation, Nitsche sufficiently pointed out the existence of two races of Br. Grubii, calling it a remarkable circum- stance. ’The postabdomen is on the average longer and slenderer in the species of Aston than in those of Branchipus. 522 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE IV. KSTHERIA CALIFORNICA Packard, and details. 1. The male, much enlarged. 2. Second antenna of female, X about 30 diameters. Fig. 3. First antenna of female, >, > “ Nice: 2 SSS SP SAASSS > , A bak Fig.3. A.S. Packard. del. T Sinclair & Sn, lith. Phila, ua! Sp tetas Ps , a x ‘ pia ey f 530 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE VIII. ARTEMIA GRACILIS Verrill. (From Utah.) Fie. 1. A dorsal view of male head and claspers; oc, ocellus;.at, lst antennae; at’, 2d antenna or claspers. Fie. 2. An anterior leg. Fig. 3. A middle leg. Fie. 4. A last leg. Fig. 5. End of abdomen. Drawn and details filled in with camera lucida by the author. bal .S. Geological Survey. ee es ee ae A.S Packard, del. ya dain Sen Tn av MOM ans OME Tol Mees Mera RR Tec SG un aie RECA SECM cant 7 Oe catch ea 532 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE IX. BRANCHINECTA PALUDOSA with details. Fig. 1. Male, at, first antenne; at’, claspers, or second antennss: p, penis (gonopoda). Fig. 2. Female. This and Fig. 1 enlarged several times. Fia. 3. First foot of male, x 50 diameters. Fic. 4. Second foot of male, x 50 diameters. Fig. 5. Tenth foot of male, x 50 diameters. Fig, 6. End of abdomen, with the caudal appendages. Figs. 1 and 2 drawn by J. H. Emerton for Bessels’ report on the Voyage of the Polaris; kindly loaned by Dr, Emil Bessels. Figs. 3-6 drawn and filled in with the camera lucida by the author. Plate IX Y Survey. U.S. Geolo gical & Son ith Finches Thor JU finerton, and A.S Packard. del. ay a a Aa if 534 FIG. FIG. FIG. Fig. Fie. Fig. Fig. Au th VO? OV CO 0D d GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE X. BRANCHINECTA PALUDOSA and B. COLORADENSIS. . Branchinecta paludosa Miill. (arctica Verrill.), first foot of male. Branchinecta paludosa Miill. (arctica Verrill.), second foot of male. Branchinecta paludosa Miill. (arctica Verrill.), tenth foot of male. . Branchinecta paludosa Mill. (arctica Verrill.), eleventh foot of male. Branehinecta paludosa Miill. (arctica Verrill.), cercopoda. . Branchinecta coloradensis Packard, first foot of male. Branchinecta coloradensis Packard, eleventh foot of male. or, del. Plate A.S Packard, de} , Thos Binclair’& Son, Lith Bi 536 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE XI. BRANCHINECTA LINDAHLI and BRANCHIPUS VERNALIS Verrill, and details. Fie. 1. Branchinecta lindahli, 10th foot, x 14 B. Fic. 2. Branchipus vernalis Verrill. Enlarged 33 times; fg, frontal process; inf, intes- tine; p, penis (gonopoda). tie. 3. Branchipus vernalis, first foot of male, x 30 diameters. Fic. 4. Branchipus vernalis, first foot of female, x 30 diameters. Fic. 5. Branchipus vernalis, eleventh or last foot, male, x 30 diameters. Fic. 6. Branchipus vernalis, end of body (cercopoda) of male. Fic. 7. Branchinecta lindahli, end of body of female, x 30 diameters. Fig. 2 drawn by Mr. E. Burgess; the other figure by the author, with the camera lucida. Thos BSinclair& Son, lath: Y Sical Survey. > Pn Mast DS Sas SSS iS: Geelo - SEO x SS ASV PSX » ~ oS Mo ti a tat ‘ ‘. _ E.Rurgese and A.S.Paclcard, del. en \aean Nee j : Y 3 Rinees aul 538 FIG. Fig. Fig. Fig. Fig. Fig, Fig. 2 3. Sixth endite of 2d foot, from Texas, x 50. 4. 5 6 GEOLOGICAL SURVEY OF THE TERRITORIES. — EXPLANATION OF PLATE XII. STREPTOCEPHALUS TEXANUS Packard, details. First foot, male from Kansas, X 4 A. First foot, male from Texas, x 50 diameters. Sixth endite of 9th foot, from Texas, x 50. . Tenth foot of specimen from Kansas, xX 50. . Eleventh foot of specimen from Kansas, x 50. 7. End of body of specimen from Kansas, X 30. Drawn by the author, with the aid of the camera lucida. Plate XI Geolosical Survey. ckard del WES. Pescen es sae | / 7 fd "HSAs nay au es aye) 540 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE XIII. CHIROCEPHALUS HOLMANI Ryder, details. Tia, 1. Foot of the first pair, with the following one, from a female; the 1st slightly overlapping the 2d foot, x 4A. ria. 2. Tenth foot of a female; the sixth endite is turned down and the fifth turned up, X +A., the third and fourth endites not seen. Fig. 3. Third foot, showing the third and fourth endites, between the 1st and 2d, and the 5th, only the latter designated by the sign />. lig. 3a. Sixth endite from the third foot. Fie. 4. Frontal process of an old, large male. Fig. 5. Frontal process of younger, smaller male. Drawn by the author, with the aid of the camera lucida. Car, eae S Feral hye Thon Sincleir& Son, Lith) » - Oe Ae ana a Tae 542 Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fia. 6. FG. 7. GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE XIV. THAMNOCEPHALUS PLATYURUS Packard, details. An anterior leg. A middle leg. A posterior leg. ' Section through the body, showing the relation of the heart, intestine (int), and nervous cord (n g, a pair of nervous ganglia cut through) to the body walls and the appendages, /5, (6, the two last pair of endites, br, the gill. The male frontal appendage; 5a, end of a branch showing the twigs, and the wrinkles and spinules with which the appendage is armed. The female frontal appendage. Side view of the head of the female without the frontal appendage, at, first antenna ; at}, claspers or 2d antennze; eye,—the eye and eye stalk. Plate XIV U.S. Geological Survey. lath Hon, o inelair & Thos §& A-S Packard, del By ats . ailt Yo > Bele Th h 544 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE XV. Fic. 1. Apus equalis Packard, 9 enlarged twice. la, upper; 16, under side of the tel- son enlarged. Fig. 2. Lepidurus couesii Packard, nat. size. 2a, side view of the same. Fic. 3. Lepidurus bilobatus Packard, nat. size. rawn by J. H. Emerton. Une Geological Survey. ry einer ELDERLY JIL Pinerton, del. Plate XV. wlain& Son, Vath eh) ony 546 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE XVI. Fig. 1. Lepidurus glacialis, enlarged nearly 3 times. la, upper, 1b, under side of the telson enlarged. Fic. 2. Apus lucasanus Packard, nat, size. 2a, upper; 2b, under side of telson, en- larged. Fig. 3. Apus newberryi Packard, nat. size. 3a, upper; 3b (on right-hand.side), under side of telson, enlarged. Fic. 4. dpus longicaudatus Le Conte, upper, 4a, under side of telson. Fic. 5. Apus himalayanus Packard, telson. 5a, under side of telson, enlarged. Drawn by J. H. Emerton. a “4 ‘e ‘“ ihe EU. S. Geological Survey : Plate XVI. “tel Net eeere cod: Fi ‘i aah ia) enero ete rrtna i nite e Thozg Sinclair & Son, Lith Baia + Fe weg ie ais 548 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE XVII. Fig. 1. Lepidurus glacialis, first foot; cl, gnathobase or coxal lobe; cl', the same of the succeeding limb. : Fig. 2. Lepidurus couesti, first foot. Fic. 3. Lepidurus couesii, first foot of another (malformed?) individual. Fig. 4. Lepidurus bilobatus, 2, first foot. Fig. 5. Lepidurus glacialis 9 , second foot. Fig. 6. Lepidurus bilobatus, 2 , second foot. Fig. 7. Lepidurus couesii, second foot. All enlarged ; drawn by the author, with the aid of the camera lucia. Thos Binclairé Son, 14! TS ae PON ee S Ply ees 550 GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE XVIII. Fic. 1. Apus equalis, 2, tenth foot. Fig. 2. Apus newberryi, 9, tenth foot, x, ‘subapical lobe.” Fiag.,3. Apus lucasanus, tenth foot, «, asin Fig. 2. Fic. 4. Apus longicaudatus, tenth foot. Fig. 5. Apus lucasanus, eleventh foot of the female, with the ovisac, containing a few eggs. Fia. 6. vy ae longicaudatus, eleventh foot of female. Fig. 7. Apus newberryi, eleventh foot of female. All the figures on this and Plates XIX-XXI much enlarged, and drawn by the author with the camera lucida. WS Geological Survey. Plate XVIt oi gill pe F Si S ~ —_ a, Lae _— 3 m or =e TA - = _ = ‘ fee se itt 1 $ A X : : } wa ie NS me —" ~ = ) ine Fig. 3 ¢ ps } z Fig. phe ee Z ( r x Mut } Sire ee - NX aS ~ : ) \ y : SENOS ~ 4 t ® . i , ~ h A A X . hy ali \s \ lire innit . an Hy La ONS rp z ‘ \ af) \ { ~-modified gill we ; Peepers Os modified gill-sac fi} wey fo ma ¥ : ue Lops \ ~~ = | er — “ | ‘ ~ ‘7 z , = : 4 ; aeeeat f ) a | nite s ~ ) ALS. Packard, del. Thos. Sinclair’ Son, Lith Ne i Oe b oe it is iy b @ 552 Fig. 1. FIG. 2. Fig. 3. Fig. 4. F14. 5. GEOLOGICAL SURVEY OF THE TERRITORIES. EXPLANATION OF PLATE XIX. Apus lucasanus, first foot; cl, gnathobase ; cl, that of the following appendage. Apus equalis, second pair of feet. Apus newberryi, 2, second pair of feet. Apus longicaudatus, second pair of feet. Apus lucasanus, ; second pair of feet; differs from the female in having the filaments on the gill. U.S. Geological Survey. . $ hos 7 ‘ * A.S. Packard, del. et eo = x 2s 3 Plate XIX a Fig. 2 gill Bill-sac ies: Fig.3 3 / ~ > “~, a ot = i 5 f 2 | / ” § . / P => ‘coxal lobe b4 ES F : = & aa ude — = — Fig 4 ; = Bey SSNS MURA SW Sr bn See ee 4 0i/ 4 i Va, f Vf. tl Wo ALS. Vackard del. T Sinclair & Son, lith. Phila. 572 GEOLOGICAL SURVEY OF THE TERRITORIES, EXPLANATION OF PLATE XXIX. Via. 1. Estheria mexicana Claus, from Kansas (2. caldwelli); first antenna ; ol, olfac- ance HIG. FIG. F1aG. Fic. Fig. FIG. Fia. 7. Fig, Fia. Fie. tory lobes; at, n, antennal nerve. la. Terminal joints of the same, filled with olfactory cells; no papill# present. 1b. Olfactory lobes from near the middle of the antenna. 2. Estheria mexicana (caldwelli); three terminal joints of the second antennsy, showing the nerve-endings and the sense-cells at the base of the sete. 3. Estheria compleximanus, edge of sixth endite (of Pl. V, fig. 7), showing the ends of the tactile nerves leading to base of tactile sete and connecting with the marginal nerve; with the two series of independent nerve or ganglion cells, X 225 diameters. 4, Estheria compleximanus Pack.; end of the dorsal lobe or oviger of one of the anterior legs (figured on Pl. V, fig. 7), showing the tactile nerve (tr) with its ganglionic enlargement near and at the end of the lohe; with the gan- glion cells at the base of the sete. . Estheria compleximanus, end of 5th endite of ist leg (Pl. V, tig. 5), showing the very large crowded ganglionic tactile cells (gc). . Branchipus vernalis Verrill. End of 1st antenna, with the three tactile seta at the tip; , antennal nerve; gc, ganglion cells, X $A. Thamnocephalus platyurus Pack. The 3d or 4th endite of the 1st foot, with n the nerve to the endite, the large ganglion cells arranged in quite regular series, and tn the origin of a tactile nerve passing into the seta(s); each seta is about to moult, as the new setw with the fine setule are present. . Thamnocephalus platyurus Pack. Portion of the edge of 1st or innermost endite of 1st pair of feet; n, nerve-fibres; gc, ganglion cells; tm, tactile nerves pass- ing into the long, slender setz (s), near tn, the marginal row of fine seta. 8a. Thamnocepholus platyurus Pack. Cuticle of flabellum with nuclei (x) and fine tubercles. 8b. Thamnocephalus platyurus Pack. Cells at base of 5th endite containing fat granules. Mia. 9. Limnetis gouldit. One eye with the cornea removed, the same specimen as repre- sented on Pl. Il, fig. 5. Op. n, optic nerve; the upper op. n. should be op. g, optic ganglion. From the peripheral nucleolated cells the nerves with the rods (if the latter are present) converge towards the optic ganglion; tr. n, transverse nerves arising from peripheral cells and connecting the two eyes. All the figures drawn with the camera lucida by the author. - Fee ee ee ied ee i = See), Wg ME gis $ Sinclair & Son, Lith phe SAS ASS iE ssa 574 GEOLOGICAL SURVEY OF THE: TERRITORIES. EXPLANATION OF PLATE XXX. Fic. 1. Branchipus vernalis Verrill. Sixth endite of an anterior leg, showing the mus- cles and tactile nerves, which arise independently of the central nervous system near the margin of the lobe; nc!, inner series; nc*, marginal series of ganglion cells; on the left side the origin of the setal nerves are seen. Fic. 2. Streptocephalus tecanus Pack. The 6th endite of an anterior foot. Fig. 3. Streptocephalus tecanus Pack.