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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 67
CAMBRIAN GEOLOGY AND PALEONTOLOGY
IV
BY GHARLES D. WALCOTT
“*BVERY MAN 1S A VALUABLE MEMBER OF SOCIETY WHO, BY HIS OBSERVATIONS, RESEARCHES,
AND EXPERIMENTS, PROCURES KNOWLEDGE FOR MEN’’—SMITHSON
(PUBLICATION 2790)
CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION 1924
< °
The Lord Baltimore (Press BALTIMORE, MD., U. S. Ae
ADVERTISEMENT
The present series, entitled ‘ Smithsonian Miscellaneous. Collec- tions,” is intended to embrace all the octavo publications of the Institution, except the Annual Report. Its scope is not limited, and the volumes thus far issued relate to nearly every branch of science. Among these various subjects zoology, bibliography, geology, mineralogy, and anthropology have predominated.
The Institution also publishes a quarto series entitled ‘‘ Smith- sonian Contributions to Knowledge.” It consists of memoirs based on extended original investigations, which have resulted in important additions to knowledge.
CHAREES: D: WALCOTT, Secretary of the Smithsonian Institution. ~
(iii)
CONTENTS
. WatcotT, CHARLES D. Nomenclature of Some Cambrian Waramlaran, Mortimat wore occurs o.oo sb csdels aes wis whee wk Published May 9, 1917. Pp. [Title] + 1-8. (Publ. No. 2444.)
. Watcott, CHarLtes D. The Albertella Fauna in British (alumina anid. Mioitamysina sets, oso sleds x eos ead o's as May 9, 1917. Pp. [Title] + 9-59, pls. 1-7. (Publ. No. 2445.)
. Waccort, CuHarLtEs D. Fauna of the Mount Whyte For- ES ETC) EG aa eR len Os a A rr
September 26, 1917. Pp. [Title] + 61-114, pls. 8-13. (Publ. No. 2480.)
PevaLcorr Cranes 1D). Appendases of Trilobites::....... December, 1918. Pp. [Title] + 115-216, pls. 14-42, text figs. 1-3. (Publ. No. 2523.)
. Watcortt, Cuartes D. Middle Cambrian Algae...........
December 26, 1919. Pp. [Title] + 217-260, pls. 43-59. (Publ. No. 2542.)
. WatcotT, CHarLes D. Middle Cambrian Spongiae........
April 2, 1920. Pp. [Title] + 261-364, pls. 60-90, text figs. 4-10. (Publ. No. 2580.)
. Watcotrt, CHARLES D. Notes on the Structure of Neolenus.
December 20, 1921. Pp. [Title] + 365-456, pls. 91-105, text figs. 11-23. (Publ. No. 2584.)
. Watcott, CHARLES D. Nomenclature of Some Post Cam- brian and Cambrian Cordilleran Formations (2).....
March 5, 1923. Pp. [Title] + 457-476, text fig. 24. (Publ. No. 2673.)
. Watcort, CHarLes D. Cambrian and Ozarkian Brachiopoda, Ozarkian Cephalopoda and Notostraca..............
June 3, 1924. Pp. [Title] + 477-554, pls. 106-126. (Publ. No. 2753.)
(v)
PAGE
115
217
261
365
457
477
ILLUSTRATIONS
PLATES
FACE PAGE i; Fanoramic: view of Mount..Bosworth.:. 0... 5.....6...4% 12 peivoss, Wace cirque and. ropes; Peden ci. '. 22%. dss fee tected, 14 3. Profile view of north cliff of Ross Lake Mountain........ 15
4-7. Illustrations of fauna of Ross Lake and Gordon shales
and of the limestones of the Ptarmigan and Chetang OULIO BAC Rap Pe Recital 52-58 SOME FA LAF CIUCOCY OLN UER sie arse ire io elvan. oe 6 wae vi @ 104 aconumenoonus and, VMesonacis 22 2... 2c vnc este es ak sss 106
10. Corynexochus, Micromitra, Acrothele, Wuimanella, and OME ee os Sw 2 Cae Pines Meas tists sen s/ei8 108
11. Crepicephalus, Ptychoparia, Olenopsis, Dorypyge, and ONAL AC oP RE gee Cac oe ea ot ae 110 C8, PSR 2007017 ot rs i822 112 ie Agraulas, Olenopsis, and’ PiyChoparia f.. wie wee eb eee ss 114 MEM NICOLERITS ANG IK UOLC NIMs? a cara iene Glade Siarkce cd ale, Seid vind oial sie» 180 Dyevecienus serratus (RoOmmMPer ies. oe 3... oe os i i 181 16. Cephalic appendages of Neolenus serratus (Rominger)... 182 i7. Nealenus serratus (Romingen) 7 sci ..c a sos 0. i votes a 183 ie. WVeoienus serratus (ROMINgEr)).a..o oe ese ss ots, Soe 184 Boe eal eniis serratus (ROMINA Ei ec. Evie oc wis%s Ghee ayepere s,s sis 0) 185 20. Branchiae—Neolenus serratus (Rominger)............. 186 Peaivesaparia. and -N Cole se ams seksy othe tins reins one'de sees © 187 22. Neolenus serratus (Rominger), illustrating exopodites.... 188 BPP OLEIIES SONPOLUS | INOMMINSETY miso soe as 'g a 0s .n since acs’s os 189 AME OIC UE Siecle lcd, ssc: x ¢ia' bo ge Rap Des 8 PIE eka ie sor teoe alae ate 190 AG ae SOreUs MAINS LOCKE jae kk tee sfa\s «x Morereiar Joana's: IQI 26. Sections of trilobites, Calymene and Ceraurus........... 193 27. Sections of trilobites, Ceraurus, Calymene, wire spirals... 195 Boum Ordawician. tilopilesmipen a ce eee el SES a ke ee ea 197 ao; Appendases of 7 riarivrus decks Gre@is: se... ee cee we 199 30. Triarthrus becki Green..... ithe Een Ole Seas Oe ne ae 201
31. Restoration of ventral surface of Neolenus serratus STEIN) 1 2Cy ys Sue Do oe ae 203 32. Restoration of ventral side of Triarthrus becki Green..... 204 33. Restoration of ventral side of Calymene senaria Conrad... 205
(vii)
Vill ILLUSTRATIONS
FACE PAGE
34. Cambrian and Ordovician trilobites with ventral appen- dages. Transverse diagrammatic sections............. 206
35. Diagrammatic sketches of thoracic limbs, trilobites and FECEHE CHUISHe COANIS st Sr Bovaate Wie vai atale cet) eae is fe revat alata ne 207 36.’ Crustacean! limb, Neolenussand: Abus. : os. .oun eee 208 a7. Trilobite tracks and stralsos > to52' 2s 2.2 tae ae og epee ee 209 38. ‘Teilobite*tracks and trails. 2 sexs 5 ote. ce eee 212 39. *Frilabite*tracks andatralls -. 30-06 sce rac Sere ae eee 213 40, Tilobite tracksfand: trails< 2.2 sca. ieee eee 214 41. ‘Inlobite;tracks*and trails... <a) ccletreiaite eo toi oe 215 42. Trilobite tracks. and annelid: trails 21.4. s.r 216 43, 44,45. Morania continens Walcott.............. 244, 245, 246
46. Nostoc commune Vaucher, N. verrucosum (Linn.) Vaucher, N. parmelioides Kutzing, and Anabaena varia- Dilts IR Ui zine s,s <2 ahh tele iote eee eee eee 247 47. Morania costellifera Walcott and M. elongata Walcott.... 248 48. Morania fragmenta Walcott and M. ? globosa Walcott.... 249 49. Morania frondosa Walcott and Morania species anderae! mined
bots a ee EMR
50, Worama parasitica Walcott 02 See ae ee 251
51. Cladophora gracilis (Griffiths) Kutzing and Dumontia ilsformis:.(ciuds,)) Greville 2 eerie aerate a ee nites 252
52. Marpolia spissa Walcott and Moramia reticulata Walcott.. 253 53. Nostoc sphaericum Vaucher, N. pruniforme (Linn.)
Agardh, and Dasya gibbesn: Harvey... ..-. 0 eee 254 54. Yuknessia simplex Walcott and Waputikia ramosa Walcott 255 55. Marpolia aequalis Walcott, Wahpia mimica Walcott, Dalyia
mitens Walcott, and D. racemata Walcott............. 256 So: Dalya racemata Walcott. +... 2<2 4 sae 257 57. Wahpia insolens Walcott, W. virgata Walcott, and Bos- worthia svmulans” Walcott, avin. 0es eee poe ee 258 58. Bosworthia simulans Walcott, B. gyges Walcott, Morania confluens Walcott, and Morania and trilobites........ 259 59. Sphaerocodium ? praecursor Walcott and S. ? cambria Wane 05 6 Gi atvesatobsg ei es sheeted seats isis Sole eee 260 60, 61. Halichondrites: elassa..Waltott')..224 7. <a ees 334, 335 62, 63.) \Tupomaciimenta Waleott? \)... 4s. nit. se eee 336, 337 64. Tuponia flexilis intermedia Walcott and Tupoma belli- lineata. Walcot® ooo oe ic. ee de VLG ghee eee ea 338
65: TFuponia fers \WValeatts (Reka. te eee eee 339
ILLUSTRATIONS ix
F FACE PAGE
66, 67,.48.. Wapita grandis Walcott... ... 60. 05. eee 340, 341, 342
SOE ORIOL CRA EN (Glo, 7 Dee ea a 343
Wah iL Gaels WCLICAbula> WV AlCOE? tis ies tet See ete eas be eae 344 71. Hazelia obscura Walcott, Hazelia ? grandis Walcott, and
arena noauljerd: VWaAlcOtt.)5.% uc tidy tne ess ss 345
72. Sentinelia draco Walcott, and Corralia undulata Walcott, Hazelia conferta Walcott, and Choia carteri Walcott... 346
73. Choia carteri Walcott and Choia ridleyt Walcott......... 347 Pape mommerialent: WW AlCOLEs 214 cy) cele a oo. 2e vy odo = Case tere 348 75. Choia utahensis Walcott and Choia carteri Walcott....... 349 76. Choia hinder (Dawson), Hagelia palmata Walcott, and iigmpronia bowerbankis Walcott: «i> < 0:6. << ese sss 350 77,78 Hamptoma bowerbankt Walcott.............006- 351, 352
79. Pirania muricata Walcott and Protospongia erixo Walcott. 353 80. Protospongia fenestrata Salter and Protospongia hicksi Maer ass) 4,22": AR MER Sie ala we alte a iw aS 354 81. Diagoniella hindei Walcott and Vauxia dignata Walcott.. 355 82. Vausxia bellula Walcott and Vausxia gracilenta Walcott.... 356
ea euaunormciionta \WalcOtioamascsie swiss ss sls Sinsise Se aie os 357 Pa metarden sar Walcott.!.-s sess acces k Paw oes REE a 358 Boe aamerio Gs CONG VWalcOttretaict v-\orcicts occiels iy sweet viele s 359
86. Eiffelia globosa Walcott and Chancelloria eros Walcott.... 360 87. Chancelloria libo Walcott, Chancelloria drusilla Walcott, Chancelloria yorkensis Walcott, and Takakkawia lineata
Me G EM ses) = $5: « /<.c x Shenae MRNMEnS SNR Girajoheieis = Slave ayes +0» 361 omcnanarilora crs, VWalcOtiawew sie «civ stzj-) se 018 oie te locos 362 89. Kiwetinokia utahensis Walcott and Kiwetinokia spiralis
WIE OLE: eis oc «0 5.x PON no os SER aN A RE oe 363 90. Tuponia lineata Walcott, Hazelia delicatula Walcott, and
EAOselianmamimularg NV AIC OLE nas wero eid ew ae nies bes we 364 g1. Limbs of Neolenus, Ceraurus, and Calymene............ 434 G2, Mxepadites and eptpadites.Of W20lenus .. ss cs se eens 435 poop ental IN COUCHES! SCHTIUN Sita. 6 sleie%s tra) ths-siwie's sle)F ac oes 436 94. Restoration of ventral surface of Neolenus serratus
(Rominger) ne Hy Ai GG cic a: ate ce eae 437 Ge ee PeiiONS 1 O MiClODLEES, - accie: cies orice la ciate wie 6 sls Sas 438, 440 Dre secuons: of trilobites (Exopodites) 02.66. c sce ea ene 442 Pee TOS SeeHOTS Oki TOMILeESs Sits e clarete ale eal x ate «eels 444-452 104. Sections of trilobites. Appendages of Triarthrus......... 454
Me ECHONSOT PIMODILES (2 ai.4 x... bi anle a en's ob 'e lo See Se ose o\6 456
x ILLUSTRATIONS FACE PAGE 106. Brachiopoda:, MicramitrarOboluscc. 2.62 a2 ee eee 534 107. e ODGUS 75 5) os che Rae Che TEAC ee ee 535 108. . Obalus, Linguleila.- 32522750, dae 536 109. ‘: Lingulella, Lingulepsis, Acrotreta, Nisusia .. 537 TIO. NESS I - i= ate g o9 hen Rn eg = ee 538 ip ps Nisusia, Wimanella, Billingsella, Protorthis. 539 112. 3 Billingsella-E oortlis” =. 8.2.4 <a dee eee 540 Li. 4 Provortiis EL Oorthis.=... won ee eee 541 II4. if FLOOTWMES Ue Ten Share Soa ee ee 542 LLG * EOorthis, -Finkelmbargia nets ccl tens ae ee 543 116. ci BOOrts © ov siaeie Bead, Da oat ee 544 iv Eoorthts.SVnuropna..sccae ants eecle ere 545 - LTO LEO Syntroplua, Huenclla,.... 2. 22<s eee ee 546, 547 120: ‘i Finenela 0020 cae ine aici eee 548 T20: 3 Balhingsella, Obolus 2-3 125 eee eee 549 122. # Lingulella, Acrothyra >. 2.5 550 123: 4 Lingulella, Billingsella. Novaya Zemlya Bra- chiopods® 4.2.) Spates. 3 ee 551 124. x Billingsella-Eoorthis. Novaya Zemlya Bra- ChiOpOds . <:<.ser. Sresteet A Se Ect ate ane 552 125. ve Huenella. Novaya Zemlya Brachiopods.... 553 126. Cephalopoda, Notostraca. Ozomia, Endoceras, Ellesmero- COVES’ WSs ciicaye is A Gin says asta gee Te ee ee 554 TEXT FIGURES PAGE Fic. 1. Anaspides tasmanie G. M. Thomson................ 171 2. Koonunga cursor Sayce.... feck jo whale te anda abe rege ae 171 2. Paranaspideslacusiris Smith... 225 0s eee 172 4, 4a. Piramia -muricata Walcott - 2 sc ccs 2 ats ore wre 299 5,6. Protospongia mononema Dawson..............-.. 303 7. Diagomella cyaithiforms Dawson... ..c vest ae ee 309 8, 8a. Kiwetinokia metissica (Dawson)................ 316 9, Vauaia gracilenia Walcott... Me Duc face ee 319 10; Eriteha. globosa-W aleottxc)s 58. citer ee oe 324 II, 12,13, 14. Diagrammatic views of structure of Neolenus serratus ( Rominget): 3c: << see. eee 371-375 ES. Lambs Of W.olenuss « tetecs0/ ons «eee eee ee 383
16. Outline of transverse section of thorax of Ceraurus... 384 17, 17a. Outlines of portion of exopodite of Calymene.... 410 18, .Photogtaph of wire. spiralse. 2 ...02..Gk 22 ae ee 411 19, 19a. Outlines of portion of exopodite of Triarthrus... 411
20.
Zils
22.
23) 24.
ILLUSTRATIONS Xi
FACE PAGE
Outline of restoration of fimbriated epipodite of NOTES a FIN ik AN to a ale seine «6 clabun ss os 419
Thoracic limb of Neolenus, Ceraurus, Calymene, and DG ARCHOS Ue ante RO le rene oth ake Gee d Sis aiacs Ud oa) «oye 421
Diagrammatic outline of a coxopodite with cross sec- tions sndicated:> ac vaunn-s Bint aD Oye ee 422 Exopodite of Triarthrus becki Conrad............... 423 Cambrian-Ozarkian-Ordovician correlation Table..... 470
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 67, NUMBER 1
CAMBRKIAN GEOLOGY AND PALEONTOLOGY
IV
No. 1. NOMENCLATURE OF SOME CAMBRIAN CORDILLERAN FORMATIONS
BY CHARLES D. WALCOTT
(PUBLICATION 2444)
CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION MAY 9, 1917
aff
The Lord Baltimore Dress
BALTIMORE, MD., U. S. A.
CAMBRIAN GEOLOGY AND PALEONTOLOGY
IV
No. 1—NOMENCLATURE OF SOME CAMBRIAN CORDILLERAN FORMATIONS
By CHARLES: D. WALCOTT
CONTENTS ne EAE E OCT TO MMMM Rote c > sess aratios cat an cro ee RE Meee TS aya Slave ayes GelSlalen ave ale algveis I Sem EL EcUtaecttln ROLMALION 4:2 5 acie.clePtieesare vere Oise cet isis. bisvalsteleis ol cvaiece siadavets g I Sechionsat ctarmican Pass ands Reales. oo cieccis ccc sews meres ceen 2 The Ross Lake shale member of the Ptarmigan formation (Albertella AEC MMe Poe Tere ras ais. s es oh 0, Rina A Eee Pa em orate a Rie cia sis Sonn Seaa ee 4 ch tatamVNOSIN TEIN OLMTAGLOM acs «ys a)s, cc esis cree rete eo wel e viel ce ol ayeaye Wels) one 4 eer iad ert SECON 5 (ora: ¢ sce eRe wees 6 ol ob oe ove sige ash whe 5 ateviewar Vo thitaltt SECCION. .. <mc nee sic sianars crave sis sia cela ciele wes’ a 5 Gre MELO HITE OMEN cree cas: sso hae ie ARERR eee re tterete cle clever Sine cies oe Acts 6 DinGenperesonmation.. Walcott. & Y.eeeee eens s Galoc ceo e selec bs ciee nes elele 7 USGI SUNK SOR a eS RAE bo, So ert ee ne eT One ar eee ae 7 Changi) ian’ Slaclley ARSe es eee eee een» 2 UR ty oe a 8 INTRODUCTION
This is the second title on this subject, the first having appeared in 1908.’ Since that date a few new names for formations of Cam- brian age in the Cordilleran area have been proposed, and I now have two new ones and a definition of one used by me in 1912.”
THE PTARMIGAN FORMATION
The name Ptarmigan formation is proposed for a series of lime- stones and interbedded shales that occur above the Mount Whyte formation.of the Lower Cambrian and beneath the Cathedral forma- tion of the Middle Cambrian in Alberta and British Columbia, Canada.
Type locality—Southeast slope of Ptarmigan Peak above Ptar- migan Lake 4.75 miles (7.6 km.) northeast of Lake Louise Station on the Canadian Pacific Railroad, Alberta.
* Smithsonian: Misc. Coll., Vol. 53, 1908; No. 1, pp. I-12. * Fort Mountain. Monogr. U. S. Geol. Surv., No. 51, p. 131, footnote a.
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 1
2 SMITHSONIAN MISCELLANEOUS COLLECTION VOL, 67
Derivation—From Ptarmigan Peak and Lake, the type locality.
Character.—Arenaceous gray limestones with interbedded bands of thinner bedded, dark bluish-black limestones and some interbedded bands of shale.
Thickness —At Ptarmigan Peak 516 feet (157.3 m.). At Ross Lake, 8.5 miles (13.6 km.) west-southwest of Ptarmigan Lake, 664 feet (202.4 m.).
Organic remains.—Middle Cambrian fauna (lower) including the Albertella fauna of Alberta and British Columbia.
SECTION AT PTARMIGAN Pass AND PEAK
The typical section was measured on the east and northeast face of Ptarmigan Peak above the Pass and Lake. It is 5.5 miles (8.8 km.) northeast of Lake Louise Station on the Canadian Pacific Railroad, Alberta, Canada. The summit of Ptarmigan Peak is formed from the Cathedral limestone, and a fine section is exposed from the summit down to the lake and on the northeast slope down to the pre- Cambrian.”
CATHEDRAL FORMATION : MIDDLE CAMBRIAN Teer
1. Massive-bedded, arenaceous, cliff-forming limestone, mostly of a light gray color but with a few dark, lead-colored bands of more or less irregular boundaries above and below. The dark bands are usually formed of more thinly bedded and a finer arenaceous limestone........ 2,100 No fossils except traces of annelid borings. The thickness of 2,100 feet is an estimate based on the height of the mountain and the height of the base of the light gray arenaceous lime- stone above Ptarmigan Lake.
PTARMIGAN FORMATION
1a. Thin-bedded, fine-grained, hard, dark gray to grayish-black arena- CEOUS TIMESEONE 2.2 hac casos oa Ne Rirals ceo pe eee ceTe ee eee 46
Fauna: (63b) Zacanthoides cimon Walcott
Neolenus constans Walcott
This bed usually breaks down to form a slope beneath the massive Cathedral limestone, but in places it forms a steep, low escarpment.
1b. Finely arenaceous limestone in thick alternating bands of a light gray and dark lead gray color. The lower 20 feet is a light gray, finely arenaceous laminated limestone, the lamella showing finely on the jveathered 4surface Vos s)h osc Ce slek ree oa hana Deoehslos neo es eae bones 270
Fauna: Traces of annelid borings occur abundantly within the layers and on their surface. The Ross Lake shale member of the Ptarmigan formation, if present, should occur about 100 feet down in this section.
Smithsonian Misc. Coll., Vol. 53, 1910, p. 420.
NO. I CAMBRIAN CORDILLERAN FORMATIONS 3
1c. Massive-bedded, bluish-gray and light gray more or less finely arenaceous limestone with many dark layers of oolitic limestone, the oolites varying from 5 to 25 mm. in diameter.............cceeeceseeee 110
Fauna: A few minute fragments of trilobite tests were seen.
1d. Thin-bedded, dark, bluish-gray limestone that may or may not
Retarnea ORtIOMe OLotMerClILL sts nttetnetetere atts ater otis ccs tehes cheatin AL melee « 28 Fauna: (63d) Lingulella sp. undt. Wimanella?
Ptychoparia (granulated species) Ptychoparia ? cilles Walcott Crepicephalus chares Walcott 1e. Finely laminated and shaly bluish-gray limestone with a few inter- eee EE U eet) 1OUVELS)..f5). > skrha terete sei ateeE Gurl Ob Beale aiele # no's Laine oes <ua'y 62 This band of almost fissile limestone and shale is a marked feature in the section. It is crossed diagonally by joint planes that cause it to weather into projecting points that give the effect of the irregular sur- face of dogtooth spar. This may be seen on the face of the cliffs of Ptarmigan Mountain for a long distance, also on Fort Mountain on the southeast side of the Pass.
Poa tmekness of Ptarmigan fOrmarion. c.¢..-4.0. eos ee coe ete re oe 516
Observations —The Ptarmigan formation is indicated in the Ross Lake section by 664 feet (202.4 m.) of hard, thin layers of more or less arenaceous limestones above the Mount Whyte formation and beneath the massive Cathedral limestones. Owing to the rapid change in character of many of the limestones within a short distance in many instances it is difficult to trace the upper and lower bounda- ries of a series of beds, like those of the Ptarmigan formation. Fre- quently a modified alteration resulting from compression or mag- nesian infiltration will completely change the appearance of the beds, and often what appears to be a solid, massive-bedded limestone, when seen in a cliff, may be a thin-bedded fossiliferous limestone where broken down by erosion. On Mount Stephen I measured the horizon of the Ptarmigan formation in the great eastern cliffs of the mountain and there all the beds appeared to form one great series of massive layers 1,560 feet (475.6 m.) in thickness.» To determine the distribution and thickness of the Ptarmigan formation in the Cordilleran area will require the extensive and thorough examination of most if not all of the accessible sections of the Middle Cambrian strata of the Canadian Rocky Mountains. It is possible that the formation is only a broad local lentile that was deposited in a depression of the Lower Cambrian sea bed. My first field impres- sion was that the Ptarmigan limestone was deposited locally in a
* Canadian Alpine Club Journal, Vol. I, 1908, p. 2309.
4 SMITHSONIAN MISCELLANEOUS COLLECTION VOL. 67
shallow basin largely as oolites before the coming of the physical change that produced the great Cathedral limestones.
It may be that it is an error to include the Ross Lake shale with its Albertella fauna in the Ptarmigan formation. That is one of the problems for the future worker in this field to determine.
THE ROSS LAKE SHALE MEMBER OF THE PTARMIGAN FORMATION (ALBERTELLA ZONE)
A name proposed for the fine siliceous shale carrying the Albertella fauna in the Ptarmigan ? formation.
Type locality.—In cliffs above Ross Lake, 1 mile (1.6 km.) south- southwest of Stephen Station on the Continental Divide and south of the Canadian Pacific Railroad. .
Deriwation——From Ross Lake where the shale is finely exposed in the cliffs above the Lake.
Character.—Dark gray, fine siliceous shale with local fillets and thin layers of gray limestone.
Thickness.—From 7 to 11 feet (2 to 3.3 m.).
Organic remains.—The known fauna includes the following:
Sponge spicules
Eocystites ? sp. undt. Micromuitra (Paterina) wapta Walcott Obolus parvus Walcott
Acrothele collenit Walcott Wimanella simplex Walcott Hyolithellus flagellum (Matthew) Hyolithellus hectori Walcott Hyolithes cecrops Walcott Agraulos stator Walcott Olenopsis cf. americanus Walcott Albertella boswortht Walcott Albertella helena Walcott Vanuxemella nortia Walcott Bathyuriscus rossensis Walcott
FORT MOUNTAIN FORMATION
In 1908 the quartzitic sandstones of this formation were described as the “ Fairview formation.”* As that name, however, was pre- occupied in American geologic nomenclature, and as the lower part of the formation was subsequently found exposed at several places on the east side of the Bow River Valley, it was decided to apply the name Fort Mountain sandstone to the whole, from the typical
* Smithsonian Misc. Coll., Vol. 53, 1908, p. 5.
NO. I CAMBRIAN CORDILLERAN FORMATIONS
cn
exposures on Fort Mountain,’ which is situated on the northeastern side of Bow Valley about 5 miles (8 km.) northeast of Lake Louise Station on the Canadian Pacific Railroad, Alberta, Canada. Here the basal conglomerate is seen in contact with the pre-Cambrian and above it there is a band of shale 44 feet (13.4 m.) thick. This basal conglomerate has a thickness of 360 feet (109.7 m.) and is much coarser than on Saddle Mountain or Mount Temple.
PTARMIGAN PEAK SECTION
Two miles (3.2 km.) to the north, on the northeast side of Ptar- migan Peak, the Fort Mountain formation is much thinner. A measured section gave:
Feet 1. Thick-bedded, light gray, occasionally cross-bedded, quartzitic sandstone with a little trace of purple color in a few layers............ 260 2. Light gray to brownish gray sandstone in thin layers.............. 22 3. Massive-bedded conglomerate, with white quartz pebbles and frag- ments of dark and greenish fine, arenaceous shale in a coarse sandstone HMGINAES 6.5 SWE BOO oe aotes BOIERGS ore On do Oot ea Dat or ees eras meet 170 “SEE ia 24,2 oS Oe IE ISIE Dee ares 2S Ar ics) i 452
[ UNCoNFoRMITY |
PRE-CAMBRIAN ARENACEOUS SHALES
The impression given by the above section is that the sediments _ were deposited on the slopes of a pre-Cambrian shore line and did not accumulate to the thickness of the deposits seen 3 miles (4.8 km.) to the south-southwest at Fort Mountain.
FarrvIEW MounrtTAIN SECTION
On the north face of Fairview Mountain above Lake Louise, 6 miles (9.6 km.) southwest of Fort Mountain, the Lake Louise shale forms a slight break in the cliffs that affords a foothold for small coniferous trees and there is usually a quantity of green mosses or lichens. Below the green vegetation the Fort Mountain formation forms a wall of hard quartzitic sandstones. This same feature is also present on the north face of the adjoining Saddle Mountain and eastward on the cliffs of Mount Temple and in the Valley of the Ten Peaks, above Moraine Lake. At Fairview Mountain the section below the Lake Louise shale is as follows:
*See Monogr. U. S. Geol. Surv., No. 51, 1912, p. 131 footnote a.
6 SMITHSONIAN MISCELLANEOUS COLLECTION VOL. 67
Fort MountTAIn ForMATION Feet
1. Massive-bedded, purplish, hard cliff-forming fine-grained, quartzitic sandstone in layers 6 inches to 3 feet thick, forming a vertical cliff in its upper 150 feet (45.7 m.). Color gray in upper layers and gradually becoming purplish colored with gray bands. Some layers are slightly CFoss-Beddedice. Scie sietelas te wie «a ‘sfc State net ME naR Ie ane ereT eT rare ee eee a 350
On Mount Temple this sandstone has a strong purple color and in the lower portion bands of arenaceous purple shale.
2. Hard gray, rather coarse-grained sandstone in the upper 200 feet (60.9 m.) with bands of shaly beds from a few inches to a foot or more in thickness. Below the sandstone becomes coarser and passes into a fine quartz conglomerate forming massive layers..............00.ee00- 570
3- wiliceous: gray and greenish gray shale. <2. 4..5 «osccoe eee 20-++
Slope covered with débris.
On the north slope of Saddle Mountain a mile (1.6 km.) southeast this shale has a thickness of 28 feet (8.5 m.) and below it about 100 feet (30.4 m.) in thickness of coarse gray sandstone to fine conglomerate is exposed. On the north slope of Mount Temple 2.5 miles (4 km.) northeast of Saddle Mountain the basal beds of the lower portion of the sandstone and fine conglomerate beds of the Fort Mountain formation rest on the dark, pre-Cambrian arena- ceous shales. The section above is not accessible for measurement.
Ten miles (16 km.) further southeast on Little Vermilion Creek the basal conglomerate is in massive layers, but the contact with the pre-Cambrian is obscured by débris.
Summary.—The Fort Mountain formation consists of four members in its greatest development:
; Feet
a.. Ouastzitie “sandstone yw snes thee a hee nee eee 350 b;, Coarse Waand stone. s5 2:25) tela tesco eae eee eter ee eae 570 ey Siliceoustsiale yc sist . 4 oS heels Greiner as aie eee 44 d. Arenaceous, quartzitic conglomerate ..............:...-- 360 Alec) bgt cs EPO eo CRT EP clininltnes beMRINr rate DE aan 1,324
It is delimited above by the Lake Louise shale and below by the basal con- glomerate resting on various beds of the arenaceous pre-Cambrian shales.
ELDORADO FORMATION
Type locality.—Prospect Peak, Eureka District, Nevada.
Derivation —From Eldorado Mine on east slope of Prospect Peak.
Character.—Gray compact limestone in massive layers.
Thickness.—3,050 feet (929.8 m.) in the Eureka District, Nevada.
Organic remains.—Middle Cambrian fauna.
This formation is described in detail by Arnold Hague as the Prospect Mountain limestone,’ but as the term Prospect Mountain quartzite preceded it the term Eldorado was proposed by Walcott,’ and the term Prospect Mountain restricted to include only the quart- zitic sandstone beneath.”
*Third Ann. Rept., U.S. Geol. Surv., 1883, p. 254. ° * Smithsonian Misc. Coll., Vol. 53, 1908, p. 184 (footnote). °Idem, p. 12.
NOI CAMBRIAN CORDILLERAN FORMATIONS
SI
DUNDERBERG FORMATION, WALCOTT *
Type locality Hamburg Ridge, Eureka Mining District, Nevada.
Its distribution is shown on the geological map of the Eureka District accompanying the Third Annual Report of the United States Geological Survey (1883, pl. XXIV).
Derivation —Dunderberg Mine, on Hamburg Ridge.
Character.—Arenaceous and calcareous shale with cherty nodules.
Thickness.—350 feet (106.7 m.) on Hamburg Ridge.
Organic remains——Upper Cambrian.
This formation is described by Arnold Hague as the Hamburg shale, but as the Hamburg limestone preceded it the term Dunder- berg was proposed by Walcott.’
GORDON SHALE
A name proposed for the fine. argillaceous shales carrying the Albertella fauna in Montana.
Type locality—On Gordon Creek 6 miles (9.6 km.) from South Fork of Flathead River, Ovando quadrangle (U. S. G. S.), Powell County, Montana. The shale extends across the ridge between Gordon and Youngs Creeks, about half-way between Gordon Mount- ain and Cardinal Peak.
Derivation—From Gordon Creek and Mountain.
Character.—Greenish and purplish fine argillaceous shale.
Thickness.—284 feet (86.3 m.) on ridge between Gordon and Youngs Creeks.
Organic remains.—The known fauna includes the following:
Alge (4v)
Hyolithes cecrops Walcott (4v)
Micromitra (Iphidella) nyssa Walcott (4q) Micromitra (Iphidella) pannula (White) (4v, 4q) Obolus (Westonia) ella (Hall and Whitfield) (4v) Lingulella sp. undt. (4v)
Acrothele colleni Walcott (4v, 4q)
Acrothele panderi Walcott (4v, 5) )
Wimanella simplex Walcott (4v, 4q, 4w) Ptychoparia candace Walcott (4v, 4q)
Ptychoparia charax Walcott (4v, 4q)
Ptychoparia pylas Walcott (4q)
Zacanthoides cnopus Walcott (4v, 4q, 4w) Olenopsis ? americanus Walcott (4v)
Albertella helena Walcott (4v, 5j)
Vanuxemella contracta Walcott (4v, 5j) Bathyuriscus belesis Walcott (4v, 4q) Bathyuriscus belus Walcott (4w)
* Smithsonian Misc. Coll., Vol. 53, 1908, p. 184 (footnote).
oO
SMITHSONIAN MISCELLANEOUS COLLECTION VOL. 67
Locality 4q=about 315 feet (96 m.) above the unconformable base of the Cambrian and 190 feet (57.9 m.) above the top of the quartzitic sandstones, on the ridge between Gordon and Youngs Creeks, about half-way between Gordon Mountain and Cardinal Peak.
Locality 4v=about 200 feet (61 m.) above the unconformable base of the Cambrian and 75 feet (22.9 m.) above the top of the quartzitic sandstones, Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River.
Locality 4w=same horizon as 4q above, on Youngs Creek, about 5 miles (8 km.) from its junction with Danaher Creek.
Locality 5j=above the quartzitic sandstones, about 6 miles (9.6 km.) west-northwest of Scapegoat Mountain, on the Conti- nental Divide between Bar Creek and the headwaters of the south fork of North Fork of Sun River, Coopers Lake quadrangle CUS Gas):
The first three localities are in Ovando quadrangle (U. S. G. S.); all four in Powell County, Montana.
CHISHOLM SHALE See Smithsonian Miscellaneous Collections, Vol. 64, 1916, p. 409.
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOLUME 67, NUMBER 2
CAMBRIAN GEOLOGY AND PALEONTOLOGY
IV No; 2;—1HE ALBERTELEA FAUNA IN BRITISH COLUMBIA AND MONTANA
(WirtH PtatTEs 1 TO 7)
BY CHARLES D. WALCOTT
(PUBLICATION 2445)
CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION MAY 9, 1917
The Lord Galtimore Press
BALTIMORE, MD., U. 8. 4.
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CAMBRIAN GEOLOGY AND PALEONTOLOGY
IV
No. 2—THE ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA
By CHARLES D. WALCOTT
(WitH PLATES I TO 7)
CONTENTS PAGE UTES SD a salt ae eR RS Re 9 ldentiication of tle eenus Albertella. 1.25.65. c eerie cee s see cee 10 ear Mata CM EISIEIOLT Pac. 3).' a's ape eee mae eee Lite ok Abe ailaeeveg od ds ined dae IT IRGRS, ILA RE Qe ee tO ns Cina cet hs Ore eee oa ee are eee 13 eR See RT = 5.62.2 PPI ns Ae ot ns Daa ho Sitio a nies Gee Ses 14 emer TT aSECIION. < ©5 oe eiiee pees aes tee cee s ek we eels eS ae ees ses 15, Faunal characteristics .......... - its 22s SE ENGI AIR aD a aL PTE IO MEI AECONISHCONSH DI ACEIt Talia, eee cee Meets ce cae bec. bine ve oles sees wiele Ig eS IMeMEO) SHPCLI ACE AUMA sh. oak eels Wow tie sn Dietde a Maclile tle die onic eee ees 20 OU S80 Scr ie EVE 2 Se Se oe ie 22 WescriptionPoimeenecan anid :SPeClESs cir a ciac Haat ders vce ve edie sd dials ele toe sie 24 ILLUSTRATIONS PLATES FACING PAGE Pee anieaume view Gb MLOUNt- DOSWOLED, oc .c.. cas each ks oie eds cow eae eee es 12 Be VoOssmeakcerctrgterand POpes mealens seeisicss one geist «vine coeelde grees bau I4 3. Profile view of north cliff of Ross Lake Mountain..................00: 5. 4-7. Illustrations of fauna of Ross Lake and Gordon shales and of the limestones of the Ptarmigan and Chetang formations........... 52-58 INTRODUCTION Hived wn
When discussing the Dearborn River section in 1908* I stated: that the Albertella fauna of the Montana sections was placed in the Lower Cambrian as the fauna was strikingly similar to that occurring in the drift blocks which were believed to have come from the lower portion of the Mount Whyte formation of the Mount Bosworth section of British Columbia; that the Mount Whyte formation was
* Smithsonian Misc. Coll., Vol. 53, 1908, pp. 202, 203.
SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No.
Io SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
placed in the Lower Cambrian owing to the presence of trilobites of the genus Olenellus; that the presence of Albertella in the Mount Whyte formation was based on the occurrence of numerous trilobitic cranidia that appeared to be generically identical with the cranidia of Albertella.
The genus Albertella was subsequently identified in the Robson Peak District in a drift block supposed to have been derived from the - Middle Cambrian Chetang formation limestone about 350 feet above the Hota formation which was referred to the Lower Cambrian.’
In 1914 Mr. L. D. Burling concluded after a thorough and admir- able study that on paleontological evidence the Albertella fauna was of Middle Cambrian age and that the specimens of Olenellus found in the Mount Whyte formation were examples of recurrence. On the basis of this conclusion Burling placed the Mount Whyte forma- tion in the Middle Cambrian.
A notice of the discovery of the genus Albertella near the line of the North Kootenay Pass by Dr. Frank D. Adams and Mr. W. J. Dick,’ when looking for deposits of phosphate of lime, escaped my attention until Dr. Adams mentioned it tome. There is nothing in the section, however, to indicate the stratigraphic position of the fossils in relation to a known Lower Cambrian fauna.
Recently (January, 1917) through the courtesy of Dr. Adams I have had the opportunity of looking over the fossils. They are not well preserved on the surface of the shaly limestone, but it is possible to tentatively determine the following genera and species:
Agraulos stator Walcott
Vanusxemella nortia Walcott Albertella bosworthi Walcott Asaphiscus rossensis Walcott
In 1916 Burling described a locality of the Albertella fauna in situ on Mount Bosworth and stated that the fauna was of Middle Cam- brian age.”
IDENTIFICATION OF THE GENUS ALBERTELLA
At the time of the preliminary identifications of the faunas, in connection with the publication of “ Cambrian Sections of the Cordil-
1 Smithsonian Misc. Coll., Vol. 57, 1913, p. 338. ? Canadian Geol. Surv., Museum Bull., No. 2, Geol. Ser., No. 17, 1914, p. 36. ® Commission of Conservation, Canada, Discovery of Phosphate of Lime in the Rocky Mountains. 8vo pamphlet. Ottawa, 1915, p. 13. ‘ *Summed up in article in American Journal Science, Dec., 1916, 4th Ser., Vol. 42, pp. 460-472.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA II leran Area,” in 1908,’ I did not fully appreciate that trilobites with almost identical cranidia might have a dissimilar thorax and pygidium and belong to quite distinct genera. This conclusion came later, when studying groups of Cambrian trilobites retaining their entire dorsal shield so that the cephalon, thorax, and pygidium of many genera might be compared.”
During the winter of 1915-16 I studied all the material available of the genus Bathyuriscus, and found that my previous conception of that genus was inaccurate,’ and that species from the Mount Whyte formation I had referred to a new genus, Bornemannia,’ were to be included under a subgenus of Bathyuriscus. Another result was to question the identification and presence of the genus Albertella in the Mount Whyte formation as it was based only on specimens of the cranidium. This was not carried further before I left for the field in June, 1916, but was taken up on my return in October. This review has now led'to the elimination of the genus Albertella from the lists of the fauna of the Mount Whyte formation and this includes the lists from localities 35e and 57e as published in the description of Bathyu- riscus (Poliella) primus.
The available field notes and fossils of the Mount Whyte formation are now being studied, but it may be necessary for me to visit some of the typical localities before expressing an opinion as to the desira- bility of including a portion of the Mount Whyte formation in the Middle Cambrian as so strongly urged by Burling.’
STRATIGRAPHIC POSITION
The exact stratigraphic position of the typical Albertella fauna was unknown to me when I went to the field in June, 1916, although Burling had stated in a general way that he had found it on Mount Bosworth in the Cathedral formation and I had a specimen from the Cathedral limestone of Castle Mountain. The fauna was originally referred to the Lower Cambrian,’ but neither in British Columbia nor Montana was there at that time a known occurrence of the fauna
* Smithsonian Misc. Coll., Vol. 53, 1908, pp. 167-220.
* See Asaphiscus. Smithsonian Misc. Coll., Vol. 64, 1916, pp. 382, 383.
* Smithsonian Misc. Coll., Vol. 64, 1916, p. 332.
*Tdem, p. 352.
*Idem, p. 353. “
*Geol. Surv. Canada, Museum Bull. No. 2, Geol. Ser., No. 17, 1914, pp. II2-115.
* Smithsonian Misc. Coll., Vol. 53, 1908, p. 202.
.
12 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 607
as a whole in situ in a section that proved to me beyond question its stratigraphic relation.
The position of the fauna found in drift blocks in British Columbia was assumed from the identification of cranidia in the Mount Whyte formation, and this was also extended to a similar fauna found in broken and isolated sections in Montana. During several field seasons in Alberta and British Columbia a general outlook was kept for traces of the Albertella fauna, but at no time was it convenient for me to go back to Mount Bosworth to systematically search for it, but in July, 1916, I began a search for the fauna in the Mount Whyte formation and the superjacent Cathedral limestones. The latter were included as in 1907 the cranidium and pygidium of a species of Albertella were found in the limestones of the Cathedral formation 275 feet (84.6 m.) above the top of the Lower Cambrian on the east shoulder of Castle Mountain, Alberta, which is 19.5 miles (31.2 km.) east-southeast of the Ross Lake section of 1915 and I had also noted the presence of the cranidium and pygidium of Albertella bosworth in débris of the Chetang formation which was referred to the Middle Cambrian.’
We knew from the collection of 1907 at Castle Mountain and from Burling’s find on Mount Bosworth that the genus was present in the Middle Cambrian Cathedral limestone, but I did not know that the genus Albertella was not present in the Mount Whyte formation. I have not discussed the finds in the Middle Cambrian heretofore as I was waiting for the time when the Albertella fauna of Mount Bosworth should be accurately located in the section.
The first section examined was that of the eastern ridge of Mount Assiniboine 18 miles (28.8 km.) southwest of Banff, Alberta, but without finding any trace of the fauna. Section after section was then studied on the main range to the north and northwest, but it was not until August 24 that the Albertella fauna was located im situ in a hanging glacier cirque above Ross Lake and 1 mile (1.6 km.) south-southwest of Stephen on the Canadian Pacific Railway. After locating the stratigraphic horizon of the siliceous shale and included Albertella fauna I crossed to the north side of the broad Kicking Horse Pass and found it after a day’s search in situ on the southern slope of Mount Bosworth west of Burling’s locality. The band of shale is from 7 to 11 feet (2 to 3.3 m.) in thickness, and the little terrace formed by it is almost always covered by dirt, broken rock,
* Smithsonian Misc. Coll., Voi. 57, 1913, p. 338.
SMITHSONIAN Je VOL. 67, NO. 2, PL. 1
Cathedral
Panoramicte best exposed Cambrian sections in the Rocky Mountains.’ Including # ™.) in thickness of strata are exposed. The approximate posi- tion of the iqot Burling is on the right toward or near A. (Photograph by
Walcott, 1916.)
_—T— «©.
~~ =
SMITHSONIAN MISCELLANEOUS COLLECTIONS
VOL. 67, NO. 2, PL. 1
“)
ia,»
-
Sherbrook
Cathedral oo
“A. Ptarmigan
si: \— Mt.Whyte t.Piran
Panoramic view of Mount Bosworth, on the Continental Divide, from Ross Lake cirque, looking north across the Kicking Horse Pass.
_ Including the Lower Cambrian sandstones on the right (east) and the Upper Cambrian Sherbrook limestones on the left (west) over 12,000 feet (3,657.4 m.) in thickness of strata are exposed. tion of the formation is indicated and the Albertella zone by A. A. Walcott, 1916.)
1 Smithsonian Misc. Coll., Vol. 53, 1908, pp. 204-217.
This is one of the best exposed Cambrian sections in the Rocky Mountains.’
The approximate posi- We found the latter fauna in situ on the left at 4, and I suppose that the locality of Burling is on the right toward or near A Photograph by p y g
NO. 2 . ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 13
trees, and brush. This so effectually conceals the band of shale that unless one knows just where to look there is little chance of finding it except in some such favorable locality as that above Ross Lake or the two known places on Mount Bosworth. The Albertella fauna is probably present all the way from Mount Assiniboine to Ross Lake, but conditions were not favorable for its discovery either in shale or limestone.
Stratigraphically the fauna as now known has a limited vertical range and a rather wide geographic distribution. The Ross Lake shale has a thickness of 7 feet (2 m.) in the Ross Lake section and about 10 feet (3 m.) on Mount Bosworth. Albertella also occurs in the adjoining limestone, but its vertical range there is unknown. :
The genus is known from the Robson Peak District about 200 miles (320 km.) north-northwest of Mount Bosworth, also about 285 miles (456 km.) to the south in the vicinity of Gordon Mountain in the state of Montana."
Albertella helena occurs in Montana and at Mount Bosworth, and Albertella bosworthi in the Robson Peak District.
Ross LAKE SECTION
Ross Lake is situated on the south side of the Canadian Pacific Railway 1 mile (1.6 km.) south-southwest of Stephen Station on the Continental Divide. The section was measured on the northeast and northwest sides of the amphitheater above Ross Lake on the north -end of the northern spurs qf Popes Peak. The base of the Mount Whyte formation rests on the purplish-colored massive quartzites of the St. Piran formation on the west slope of the east spur and about 500 feet (152 m.) above Ross Lake ; the summit of the section as given here is on the east face of the west spur.
MrippLtE CAMBRIAN CATHEDRAL FoRMATION
Cliffs of massive-bedded rough arenaceous limestone rise one above the other to the summit of the ridge. At Mount Bosworth on the north side of the Kicking Horse Pass the Cathedral limestones have a thickness of 1,086 feet (334 m.) exclusive of a lower division of 509 feet? (156.6 m.), which I have now included in a recently recognized formation named Ptarmigan from its typical section on Ptarmigan Mountain above Ptarmigan Pass, 8 miles (12.8 km.) east- northeast of Ross Lake.
* Smithsonian Misc. Coll., Vol. 53, 1908, pp. 18-22. * This is 1c-f of the Cathedral formation section of 1908 (Smithsonian Misc. Coll., Vol. 53, 1908, p. 212).
14
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.
PTARMIGAN FORMATION 1. Thin-bedded, more or less arenaceous and mottled limestone... 1a. Bluish-gray limestone in thin irregular layers interbedded in a steenish siliceous shale... Jo)... 02% 2. we ee amas one ns oe ene 2. Greenish and dark gray, compact siliceous shale weathering to a light gray color when long exposed. The shale forms compact, solid, hard layers from 2 to 3 feet (0.6 to 0.9 m.) thick that break first into blocks on joint planes and then split up into shale on long exposure to frost and watef.. s,s. 25 ec eso cele vere « eet This is the Ross Lake shale member of the Ptarmigan formation which is characterized by the Albertella fauna which is most abun- dant in many places in it. At the Ross Lake section the fauna includes (Loc. 63j): . Siliceous sponge spicules Eocystites ? sp. ? Micromitra (Paterina) wapta Walcott Obolus parvus Walcott Acrothele colleni Walcott Wimanella simplex Walcott Hyolithellus flagellum (Matthew) Hyolithes cecrops Walcott Agraulos stator Walcott Olenopsis cf. americanus Walcott Vanuxemella nortia Walcott Albertella bosworthi Walcott Albertella helena Walcott Bathyuriscus rossensis Walcott On the slope of Mount Bosworth the shale is a little thicker and we collected from it in situ (Loc. 63m.) : Acrothele colient Walcott Wimanella simplex Walcott Hyolithes cecrops Walcott Agraulos stator Walcott Vanuxemella nortia Walcott Ptychoparia sp. undt. Olenopsis cf. americanus Walcott Albertella boswortht Walcott Albertella helena Walcott Bathyuriscus rossensis Walcott From the boulders (Loc. 35c) found below the outcrop on the south slope of Mount Bosworth in earlier years there have been collected: Micromitra (Paterina) wapta Walcott Obolus parvus Walcott Acrothele collent Walcott Wimanella simplex Walcott Hyolithellus fagellum (Matthew) Hyolithellus hectori Walcott
67
Feet 155
(‘1001 “af ‘xneA as8100r5 Aq ydeisojoyg) “€ 9}e][d YIM UOTJDaUUOD UT PaIpNys aq pyhoys MIA sIyT ‘pod WeII}S IY} UL SYOTG asny UL M990 9UOZ Y]JAJ4aq] 7 IY} JO sayeys Yep dy} PJD ey} JOAO sanod wessjs dy} stoYyM aAoqe Jsn{ “PpawI1OF SI ISpo] MOJIeU B IIOYM JYSII oY} UO OSTR puke UMOYsS ATIRaII SI UOZ DJIJAIG] P MOIIVU ‘Yep dy} Ie] 94} UO P JY ‘Ffe] VY} UO aSphy oye] ssoy pure ‘jys Je Yeog ovsieN ‘Jojusd ul yvog sodog ‘epeuey) ‘eIquinjoD ystig ‘Aemyiey oylorg ueIpeuey) 9Y} UO ‘aplAIq [eJUeUTJUOD ‘uayda}g JO YNos pue sseq IsIOT]Z SUIYI YS JO opis YINOs dy} UO aNbAIO ayRT] ssoY fo Mor
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Z@ ‘Id ‘@ “ON ‘29 “10A SNOIL9031109 SNOANVIISOSIN NVINOSHLIWS
SMITHSCNIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 2, PL. 3
CATHEDRAL
PTARM/GAN
MT. WHYTE
ST PIRAN,
North profile of ridge above and southeast of Ross Lake, 1 mile (1.6 km.) south of Stephen Station on the Canadian Pacific Railway.
The position of the Albertella zone is shown at A where the thin band of shale forms a dark, narrow band that may be seen from the Kicking Horse Pass.
The relative positions of the Cathedral, Ptarmigan, Mount Whyte, and St. Piran formations are indicated on the plate.
This view should be studied in connection with plate 2. (Photograph by Walcott, 1916.)
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 15
Hyolithes cecrops Walcott Agraulos stator Walcott Ptychoparia sp. undt. Olenopsis cf. americanus Walcott Vanuxemella nortia Walcott Albertella bosworthi Walcott Albertella helena Walcott Bathyuriscus rossensis Walcott Feet 3. Massive-bedded, gray and mottled, rough weathering arena- Ee TIS MIILES [OME et. tel Sorel ie anes estan saree ore oes ous Lo Siaca-o Bao wie evar 160
5. Massive-bedded, dirty gray colored, rough weathering calca- GEOUSMSAGSHOM Chea soi. cand eR ae scihevele alas wale 6 eve ee wed 275 6. Alternating layers of bluish-black and steel-gray hard limestone 52
Hotalareterted to etapimicam mOGMAtMOM. 4.06 0..te 00+ 100 de oe - 664 Lower CAMERIAN Mount WHuyte ForMaAtion 1. Gray to grayish-black thin-bedded oolitic limestone............ 43 Fossils: Many small fragments of trilobites.
At this horizon 5.5 miles (8.8 km.) to the south at the west foot of Mount Shaffer, British Columbia (Loc. 61d), the following fauna has been collected :
Acrotreta sagittalis taconica Walcott Nisusia (Jamesella) lowi Walcott Scenella varians Walcott
Pelagiclla sp. undt.
Micronutra (Paterina) labradorica (Billings) Micromitra (Iphidella) pannula (White) Corynexochus senectus (Billings) Agraulos unca Walcott
Zacanthoides
“Ptychoparia (Emmrichella) lux Walcott Ptychoparia sp.
Mesonacis gilberti (Meek)
2. Finely banded gray sandstone and hard arenaceous limestone... 5
3. Gray, finely oolitic limestone in thick beds that break down CMT Ie OU at lay LSet ee vole ia oe ales Socisid swe velscessss 18
Fauna: At 15 feet from summit (Loc. 63k) : Nisusia (Jamesella) lowi Walcott Pelagiella sp. undt.
Helcionella elongata (Walcott) Scenella varians Walcott Hyolithes billingsi Walcott Ptychoparia cercops Walcott Ptychoparia pia Walcott Olenopsis agnesensis Walcott
16 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
Feet 4. Banded sandstone and finely arenaceous shale in massive beds that break down on weathering into shaly arenaceous layers usually covered more or less thickly with annelid trails and more rarely
tracks of trilobites? 2... ccccscte i actecticreeia tien eh ee ae Chee ee 70 5. Greenish, drab and buff-colored very fine siliceous shale with pattings of thin layers of Ccompact,sandstone.... .....- es -eeeeeee 85
Fossils: Noted a valve of Micromitra and cranidium of Ptychoparia. 6. Calcareous sandstone with dirty brown and rusty layers and shaly sandstone parting@s. «2... cc. s<cksfincs's ss soa oe eee 27 Fossils: Corynexochus fieldensis Walcott Olenellus (many fragments ) — Total thickness of Mount Whyte formation................. 248 St. Prran ForMATION
Massive-bedded purplish quartzitic sandstones that form cliffs above Ross Lake.
The above sections of the Mount Whyte and Ptarmigan forma- tions show that the Albertella fauna is located in the Ross Lake section some 500 feet (153.8 m.) above the top of the Mount Whyte formation and the Olenellus fauna. In the section of Castle Moun- tain 15 miles (24 km.) southeast of Ross Lake a specimen of the pygidium of Albertella boswortht was found in 1907 260 feet (79.2 km.) above the Mount Whyte formation in a thin-bedded limestone that was then referred to the Cathedral formation, but which is now included in the Ptarmigan formation.
MONTANA AREA
In Montana the Albertella zone is weil developed in Powell County at localities about 285 miles (456 km.) south of Kicking Horse Pass, British Columbia, and 135 miles (216 km.) south of Dr. Frank D. Adams’ locality near North Kootenay Pass. The Cambrian section in this area, as I measured it in 1905, resembles that of Dearborn River and that of the Little Belt Mountains, but as the known fauna is different in the lower shale containing Albertella, I have named that shale the Gordon shale.
GORDON MOUNTAIN SECTION
The section is exposed along the ridge between Youngs Creek and Gordon Creek. The base of the section begins on the saddle beneath the limestone cliff half-way between Gordon Mountain summit and Cardinal Peak, and extends east-northeast along the ridge above- mentioned. Beginning with the top of the section we have the following succession. The section above ta of the Yogo limestone is cut off by a twist and a fault in the beds.
NO.2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 17
Yoco LIMESTONE Feet
1a. Light gray limestone in layers 3 to 8 inches thick. It is oolitic in some layers and has many annelid borings and trails.............. 430 ie Warkeray linestone similar to Ta: e222... .60. Fo. ec ae 190
Strike E. and W., dip 45° N. (Mag.). 1c. Thin-bedded, bluish-gray limestone with many annelid borings Suivdl - UEC on Bech a eka o cuceenG tacts caches CUCUCIER i aie, A 215
protalvor voroulimestonen meri vaclesce eek cette acces beak 835 Dry CrEEK SHALE 2. Green, argillaceous shale with a few thin layers of limestone inter- bedded. The thickest of these is a band 3 feet thick 20 feet from
PEERS et us 85. 27a. Xm warden a aT eda sie oe TS en sii ines erase leas es 64 Fauna Micromitra Hyolithes Asaphiscus (like wheelert) Ptychoparia
Pincrim LIMESTONE 3. Thin, irregular layers of bluish-gray limestone that form massive layers when not broken dowin’ bysweathering. .. 60.20 je. loccee ese cee 545 ‘Traces of fossils Dip reaches 80° near the top. PARK SHALE 4. Green and gray argillaceous and arenaceous shale............... 47 Fauna, locality 8): Micronutra (Paterina) superba Walcott Bathyuriscus sp. undt. Ptychoparia sp. Zacanthoides sp. MEAGHER LIMESTONE 5. Thin-bedded, gray, arenaceous limestone becoming purer a little SIONS HDS BSE TE Arete ee Pes tre cn he rr 145 At 45 feet above the base the beds become more massive but break down into thin layers on weathering. Fragments of fossils occur. GorDON FoRMATION 6a. Chocolate or purple argillaceous and sandy shales.............. 64 Fauna: Fragments of a fauna appear here which is well developed in 6b. 6b. Dark greenish argillaceous shales, weathering a lighter green... 35 Fauna, locality 4q: Micromitra (Iphidella) nyssa Walcott Micromitra (Iphidella) pannula (White) Acrothele collenit Walcott Wimanella simplex Walcott Ptychoparia candace Walcott Ptychoparia charax Walcott Ptychoparia pylas Walcott Bathyuriscus belesis ? Walcott (Pygidia) Zacanthoides cnopus Walcott
18 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
Feet 6c. Layers of impure, gray weathering, buff-colored limestone with bands of dark greenish shale between thee siete Magee e ieitks a ee ee eee 21 6d. Greenish and bluish-gray argillaceous shales mat irregularly interbedded sandy shales and thin layers of compact gray sandstone... 164 At 82 feet (25 m.) from the base a thin layer of sandstone contains fragments of Albertella and the shales above carry quite a fauna. Locality 4v at the foot of the ridge on Gordon Creek is con- sidered to come in at about this horizon. It is 75 feet (22.9 m.) to 90 feet (26.8 m.) above the sandstone of 7a. It includes— Alge Hyolithes cf. cecrops Walcott Micromitra (Iphidella) pannula (White) Obolus (Westonia) ella (Hall and Whitfield) Lingulella sp. undt. Acrothele colleni Walcott Acrothele panderi Walcott Wimanella simplex Walcott Ptychoparia candace Walcott Ptychoparia charax Walcott Olenopsis americanus Walcott Albertella helena Walcott Bathyuriscus belesis Walcott Vanuxemella contracta Walcott Zacanthoides cnopus Walcott Hyolithes and Ptychoparia occur below in several bands of greenish argillaceous shale between more sandy layers. — Rotaliot Gordons tonmationn. pee sso seat ee eee 284 FLATHEAD ? SANDSTONE 7a. Thin-bedded greenish and brown Shdetone with shaly sand- stone partings. Annelid borings and trails, mud cracks and ripple IMATICS OCCUN ere sabre oie o Sle AIH. ct cleo cele rae helehe ore cde ar oon oe ee 43 Strike E. and W. (magnetic), dip 48° N. Fauna: See footnote.’ 7b. Gray sandstone in thick beds, some of which are a fine quartz conglomerate with pebbles up to one-fourth of an inch in diameter.... 82 In a thin arenaceous layer 20 feet (6 m.) above the contact with the Algonkian strata numerous fragments of a species of Albertella were found. otal ofsblatheadmn sandstone yan sec eieei eet sane 125
* At locality 150d, on the Continental Divide, about 24 miles (48.6 km.) north- west of Scapegoat Mountain and 12 miles (19.2 km.) northeast of Gordon Mountain, the Albertella fauna occurs in a thin-bedded shaly, browish sand- stone. The following species were found:
Crusiana sp. undt.
Agraulos cf. stator Walcott Albertella cf. helena Walcott Vanuxemella contracta Walcott
This locality is of importance as it extends the stratigraphic range of the fauna to the sandstones beneath the horizon of the Gordon shale.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA I9Q
RESUME
Feet TARVOR TH UITESUONE (Cle. SeiacirMOE ie tek algae he ita ie eces 835 Pray Cte Shales woe ate tiees ts cella ts ode Gated «cles 64 Serb oni lime stOmes cp Mette: hicsaisiss ols crokeriare ora vaa/dera 6 545 dig JPBVEE SSS REAR lg CO OFS ei oe aOR SISOS ORIG aes Ce eee 47 Eee Vieaciren tittnlesStOnlen spaaeeiae cae sien. o o's bitrnks. oo c/s cxerarerere or 145 Pe OL OISHAG at oe Sn nee es Lae Sud ea sccee es 284 pet biathede © -Satidstonesktanet a ites es, cer dae is hones sais 125
Tove TR Rees cers Ook coe Ga SOE ICE a OIE Mio esere 2,045
The Cambrian section rests on gray and red shales and hard sandstones of the Camp Creek series (Walcott, 1906*) of the Algonkian. This section is, as far as known, on the western limit of the Cambrian strata in Montana. To the north the same series extends north up the valley of the South Fork of Flathead River.
FAUNAL CHARACTERISTICS
The fauna of the Ross Lake shale or Albertella zone is of interest both from its biological and stratigraphic aspects. Biologically, it represents a small subfauna of the Middle Cambrian that is rich in brachiopods and trilobites. The shale in which it occurs indicates very favorable conditions for the presence of a much more varied invertebrate life but as yet the fauna is limited to 14 known genera and 16 known species. .
RELATIONS TO SUBJACENT FAUNA
The fauna of the subjacent Mount Whyte formation has been misunderstood very largely through tentatively including in it the Albertella fauna of the superjacent Ptarmigan formation. With this eliminated we find the fauna at the base of the Mount Whyte forma- tion of a Lower Cambrian facies, and near the summit the Lower Cambrian fauna still predominating but with some genera that are much more developed in the Middle Cambrian fauna above, notably Crepicephalus, which is represented in the upper beds of the Mount Whyte formation.
I have already mentioned the difficulty met with in identifying the genus Albertella from fragments of the cephalon. The cranidium of Alberteila is similar in form to some species of Bathyuriscus, notably that of B. (P.) primus, which occurs in the Mount Whyte formation. This is best seen by comparing the cranidia of the two genera as
* Bull. Geol. Soc. America, Vol. 17, 1906, p. 3.
20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
illustrated for Albertella on plates 1 and 2, Vol. 53, Smithsonian Miscellaneous Collections, 1908, and for Bathyuriscus primus on plate 46, Idem, Vol. 64, 1916. Thinking that probably the specimens of Albertella helena and A. bosworthi found in loose blocks came from a siliceous shale of the Mount Whyte formation, I identified separate cranidia from that shale as Albertella, but now that I know that Albertella helena and A. bosworthi in the Canadian Rockies section occur in a siliceous shale 500 feet (152.4 m.) or more above the Mount Whyte formation and that no typical form of the pygidiwm or thorax of Albertella is known to have been found in the siliceous shales or limestones of the Mount Whyte formation I do not hesitate to refer the cranidia from the Mount Whyte formation to Bathyu- riscus (P.) primus. This removes Albertella from the Mount Whyte formation and restricts it to the Ross Lake shale and the Albertella zone, and the limestones of the Ptarmigan formation in which the Ross Lake shale occurs.
The remaining species of the Albertella shale: fauna that were
identified as occurring in the Mount Whyte formation are: Micromitra (Paterina) wapta Walcott Obolus parvus Walcott Acrothele collent Walcott
Another species that occurs higher up in the Middle Cambrian section, but not in the Albertella zone, is Micromitra (Iphidella) pannula (White).
A careful study of the specimens that were hastily identified when writing out the geologic sections in 1908" results as follows in rela- tion to the species assumed to be identical from the Albertella zone and the Lake Agnes shales of the Mount Whyte formation.
Micronmitra (Paterina) wapta Walcott—Fragments of larger specimens of Micromitra (P.) pannula White were identified as Micromitra (Paterina) wapta by me in 1908 and credited to (locality 35e) the Mount Whyte formation, where they occur with Acrothele n. sp. In the form of fragments and with the outer surface injured or exfoliated it is exceedingly difficult to recognize characters that with better material indicate specific differences.
Obolus parvus Walcott from (locality 35c) the Albertella zone is a small species nearly circular in outline. The species identified with it from (locality 58t) the Mount Whyte formation is represented by the interior of a ventral valve that is distinctly elongate and with
* Smithsonian Misc. Coll., Vol. 53, 1908, pp. 204-217. * Idem, p. 214, 3 of section.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND-MONTANA 2I
a very definite and nearly straight cardinal slope from the beak outward to the lateral margins of the valve, and it is not Obolus parvus. ‘The specimens identified as Obolus parvus from (locality 35e) the Mount Whyte formation * were probably dorsal valves of young shells of Acrothele n. sp., which is abundant but usually poorly preserved.
Acrothele colleni was identified from Mount Stephen in tc of section. The specimens differ from the types of A. colleni from the Albertella zone in uniformly smaller size and the presence in the dorsal valve of a very long and strong median ridge, in this respect resembling Acrothele bellula of the Middle Cambrian of Alabama.
By oversight Mesonacis gilberti is given as occurring in the fauna of the Lake Agnes locality (35e).* It occurs in the same stratigraphic section but at a lower horizon. On the opposite side of the Victoria Range at Mount Shaffer M. gilberti occurs above the horizon of the Lake Agnes shale fauna (35e) at locality 61d associated with a typical Lower Cambrian fauna (List, p. 15).
RELATION TO SUPERJACENT FAUNA
The Albertella fauna is a small subfauna that includes primitive forms usually found in the Lower Cambrian fauna, such as Micro- mitra (Paterina) wapta, Agraulos stator, along with typical Middle Cambrian forms. The next well-known superjacent fauna is the so-called Ogygopsis fauna of the Stephen formation and just above this the Burgess shale fauna, both of which are well-known Middle Cambrian subfaunas. Between the Albertella zone and the base of the Stephen formation there is a series of almost unfossiliferous limestones forming the upper 165 feet (50.3 m.) of the Ptarmigan formation and also the entire Cathedral formation of about 1,000 feet (304.8 m.) in thickness. That the period between the Albertella zone and the Ogygopsis zone was of considerable length is evidenced by the change in the faunas and by the appearance of a greater diversity of forms in the Ogygopsis zone. This latter statement is qualified by the possibility of the Ogygopsis fauna being an immi- grant fauna from outside of the area where it is now found.
One of the problems now is to find the subfauna or faunas that existed in early and late Ptarmigan time and throughout the period
* Smithsonian Misc. Coll. Vol. 53, 1908, p. 214, 3 of section. * Idem, listed on p. 213.
°U. S. Geol. Surv. Monogr., No. 51, 1912, pl. 58, figs. 5f, 5h: “Idem, p. 130.
. 22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
of deposition of the Cathedral formation. That this can be success- fully accomplished by a systematic search in the Robson Peak Dis- trict and to the north of it is quite possible as there are a number of interbedded bands of thin-bedded limestones in the Chetang forma- tion and bands of shale in the Hitka formation which appears to be below the horizon of the Ogygopsis shale zone of the Stephen formation. NOTES ON THE FAUNA
In order that the geologist and paleontologist may have before them what is known of the Ross Lake shale fauna as a whole, also the Albertella fauna of the Gordon shale and the limestone of the Ptar- migan formation and the Chetang formation, I have brought together on plates 4-7 illustrations of the species known to me as they have been found in the vicinity of Kicking Horse Pass, British Columbia ; in Montana, and the Robson Peak District, Alberta. The following references are simply for the purpose of indicating where the old species are described, also the plates on which illustrations may be found in this paper. J
The species from the Gordon shale have (Gordon) after the specific name; those from the Chetang limestone (Chetang) ; those from the Ptarmigan limestone (Ptarmigan), and those from the Ross Lake shale are without a designation.
Thohasterella ? hindei n. sp., pl. 4, figs. I, Ia
Eocystites ? sp. undt., pl. 4, fig. 2.
Micromitra (Paterina) wapta Walcott (Monogr. 51, U. S. Geol. Surv., 1912, p. 357), pl. 4, fig. 3
Micromitra (Iphidella) nyssa Walcott (Gordon) (Idem, p. 360, pl. 3, fig. 9)
Micromitra (Iphidella) pannula (White) (Gordon) (Idem, p. 361, pl. 4, fig. Ig) ;
Obolus parvus Walcott (Idem, p. 408), pl. 4, figs. 4, 4a
Obolus (Westonia) ella (Hall and Whitfield) (Gordon) (Idem, p. 455, pl. 47, fig. 1b)
Lingulella sp. undt. (Gordon)
Acrothele colleni Walcott (Idem, p. 640), pl. 4, figs. 5, 5a-f
Acrothele panderi Walcott (Gordon) (Idem, p. 651, pl. 50, fig. 5)
Wimanella simplex Walcott (Idem, p. 748), pl. 4, figs. 6, 6a-c, 7, 7a-c, 8, 8a-c
Nisusia cf. alberta Walcott (Chetang:), pl. 4, fig. 9
Hyolithellus flagellum (Matthew) (Canadian Alpine Journ., Vol. 1, 1908, pl. 1, figs. 8, 8a), pl. 5, figs. 2, 2a
Hyolithellus hectori n. sp., pl. 5, fig. 1
Hyolithes cecrops n. sp., pl. 5, figs. 3, 3a-c
Agraulos stator Walcott (Smithsonian Misc. Coll., Vol. 64, 1916, p. 173), pl. 6, fig. 6
Agraulos sp. undt. (fragment of a cranidium)
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 23
Ptychoparia candace n. sp. (Gordon), pl. 6, figs. 3, 3a
Ptycheparia charax n. sp. (Gordon), pl. 6, fig. 1
Ptychoparia ? cilles n. sp. (Ptarmigan), pl. 6, fig. 2
Ptychoparia pylas n. sp. (Gordon), pl. 6, figs. 4, 4a-c
Ptychoparia sp. undt. ;
Crepicephalus chares n. sp. (Ptarmigan), pl. 6, figs. 5, 5a-c
Vanuxemella contracta Walcott (Gordon) (Smithsonian Misc. Coll., Vol. 64, 1916, p. 221, pl. 36, figs. 4, 4a)
Vanusxemella nortia Walcott (Idem, p. 222), pl. 7, fig. 7
Olenopsis americanus Walcott (Gordon) (Idem, Vol. 57, p. 243, pl. 36, figs. 8-11) .
Olenopsis cf. americanus Walcott (Idem), pl. 6, figs. 8, 8a-b
Albertella boswortht Walcott (Idem, Vol. 53, 1908, p. 22), pl. 7, figs. 2, 2a-b, 3, 3a-d
Albertella helena Walcott (Idem, p. 19), pl. 7, figs. 4, 5, 5a
Albertella levis n. sp. (Chetang), pl. 7, figs. 1, 1a
Zacanthoides charilla n. sp. (Chetang), pl. 6, figs. 9, 9a
Zacanthoides ? cimon n. sp. (Ptarmigan), pl. 7, figs. 6, 6a
Zacanthoides cnopus n. sp. (Gordon), pl. 6, figs. 10, Toa
Neolenus constans n. sp. (Ptarmigan), pl. 6, figs. 7, 7a
Bathyuriscus belesis Walcott (Gordon) (Smithsonian Misc. Coll. Vol. 64, I916, p. 338, pl. 50, figs. 1, Ia-1)
Bathyuriscus belus Walcott (Gordon) (Idem, p. 339, pl. 50, figs. 2, 2a-d)
Bathyuriscus yossensis n. sp., pl. 5, figs. 5, 5a-d
Bathyuriscus cf. rossensis n. sp., pl. 5, figs. 6, 6a
Bathyuriscus (Poliella) chilo n. sp. (Ptarmigan), pl. 5, fig. 4
Bathyuriscus (Polhella) sylla Walcott (Chetang) (Smithsonian Misc. Coll. “Vol. 64, 1916, p. 354, pl. 48, figs. 3, 3a-f)
The fauna of the Gordon shale in Montana includes (4q, 4v):
Algze *Hyolithes cf. cecrops Walcott Micromitra (Iphidella) nyssa Walcott Micromitra (Iphidella) pannula (White) Obolus (Westoma) ella (Hall and Whitfield) Lingulella sp. undt. *Acrothele collent Walcott Acrothele pandert Walcott *Wimanella simplex Walcott Ptychoparia candace Walcott Ptychoparia charax Walcott Ptychoparia pylas Walcott *Olenopsis americanus Walcott *Albertella helena Walcott Bathyuriscus belesis Walcott *Vanuxemella contracta Walcott Zacanthoides cnopus Walcott
* The species common to the Gordon shale and the Ross Lake shale are marked by an asterisk.
A)
Nn
24 MITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
From the Chetang formation only six species were collected :
Nisusia cf. alberta Walcott
Albertella bosworthi Walcott
Albertella levis Walcott
Agraulos cf. stator Walcott
Zacanthoides charilla Walcott ; Bathyuriscus (Poliella) sylla Walcott
The Ptarmigan formation limestones have yielded but six species:
Ptychoparia cilles Walcott Crepicephalus chares Walcott Albertella bosworthi Walcott Zacanthoides ? cimon Walcott Neolenus constans Walcott Bathyuriscus (Poliella) chilo Walcott
DESCRIPTION OF GENERA AND SPECIES THOLIASTERELLA Hinde
Tholiasterella H1inbE, 1888, Monogr. British Fossil Sponges, Pal. Soc., Lon- don, Pt. II, p. 168. (Described and discussed. )
Dr. Hinde describes the sponge spicules referred to this genus as follows:
Form of Sponge unknown; the skeleton consists of spicules, which . . . bear a general resemblance to the handle and ribs of an umbrella. The handle or vertical ray of the spicule supports on its summit a variable number of rays which radiate from it in a generally horizontal direction. A central disc of variable proportions is formed by the union of the bases of the horizontal rays and the upper surface of this, and of the rays, may be either smooth or covered with tubercles or blunted vertical spines.
Dr. Zittel, in speaking of the genus, says: “As a rule, two of the rays lying in the same plane divide dichotomously from the nodes outward, so as to produce a six-armed instead of a four-armed cross.” *
Stratigraphic range—Carboniferous.
It is not probable that the Middle Cambrian species now described belongs in this genus, but with only the spicules flattened in the shale for comparison it does not seem best to found a new genus for them. The six-rayed spicule with a central nodule suggests some forms of the spicules referred to Tholiasterella. They appear to be more nearly related to the latter than to the spicules of Astre- ospongia Roemer from the Silurian.’
* Text-book Pal., edited by Eastman, Vol. 1, 1913, p. 62. * As defined by Hinde. Fossil Sponges, pp. 133-134, pl. 1, figs. 7, 7a-d.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 25
THOLIASTERELLA ? HINDEI, new species Plate 4, figs. I, Ia
Six-rayed spicules with a central canal in the rays, a tubercle where the ray merges into the central disc of the spicule, also a central tubercle which suggests that it may have been the base of a central ray or shaft.
There is a trace of longitudinal, raised lines on one of the arms. The type spicule measures 16 mm. from tip to tip of opposite rays.
The original substance of the spicule has been replaced by the dark siliceous sediment forming the shale.
The doubtful character of the generic reference is mentioned in the note on the genus.
Formation and locality—Middle Cambrian: (63}]) Ross Lake shale member of the Ptarmigan formation; cliffs above Ross Lake 1.5 miles (2.4 km.) south-southwest of Stephen on the Canadian Pacific Railway, British Columbia, Canada.
EOCYSTITES ? species undetermined Plate 4, fig. 2
A single crushed specimen of the calyx and arms of this species is all that is known of it. There is not sufficient evidence on which to base an accurate generic and much less a specific determination.
Formation and locality—Middle Cambrian: (63j) Ptarmigan formation, Ross Lake shale; outlet of cirque above and south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south- southwest of Stephen on Canadian Pacific Railway, British Columbia, Canada.
BRACHIOPODA
MICROMITRA (PATERINA) WAPTA Walcott Plate 4, fig. 3 Micromitra (Paterina) wapta Watcott, 1912. (See Monogr. 51, U. S. Geol. Surv., 1912, p. 357, text figs. 29, A, B.) OBOLUS PARVUS Walcott Plate 4, figs. 4, 4a Obolus parvus Watcortt, 1912. (See Monogr. 51, U. S. Geol. Surv., 1912, p. 408, text figs. 37, A, B.) ACROTHELE COLLENI Walcott Plate 4, figs. 5, 5a-f
Acrothele colleni Wavcort, 1912. (See Monogr. 51, U. S. Geol. Surv., 1912, p. 640, text figs. 55, A-E; pl. 63, figs. 6, 6a-b.)
26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
WIMANELLA SIMPLEX Walcott Plate 4, figs. 6, 6a-c, 7, 7a-c, 8, 8a-c
Wimanella simplex Watcott, 1912. (See Monogr. 51, U. S. Geol. Surv., 1912, p. 748, text fig. 64; pl. 80, figs. 2, 2a-e.)
NISUSIA cf. ALBERTA Walcott Plate 4, fig. 9 Nisusia alberta Wa.cott, 1889. (See Monogr. 51, U. S. Geol. Surv., 1912, p. 720, pl. 100, figs. 3, 3a-d.)
Only one small ventral valve of this type has been found in the Chetang limestone. It is strikingly similar to the small shells referred to Nisusia alberta as found in the shales and limestones of the central and lower portions of the Stephen formation at Mount Stephen, British Columbia.
The narrow, rather strong radiating ribs with nodes on them indi- cating spines and minute pores penetrating some of the layers of the shell indicate the genus Nisusia.
Formation and locality —Middle Cambrian: (610) Chetang for- mation ; gray shaly limestone in massive beds; on northeast slope of Chetang Cliffs above Coleman Glacier Creek, 7 miles (11.2 km.) north-northeast in direct line from summit of Robson Peak, north- west of Yellowhead Pass, western Alberta, Canada.
HYOLITHELLUS FLAGELLUM (Matthew) Plate 5, figs. 2, 2a
Urotheca flagellum Matruew, 1899, Trans. Roy. Soc. Can., 2d ser., Vol. 5 Sec. 4, p. 40, pl. 1, fig. 1. (Species described and figured.)
Hyolithellus fagellum WW aAucort, 1908, Canadian Alpine Journ., Vol. 1, No. 2, p. 14, pl. 31, figs. 8, 8a. (Changes generic reference and illustrates species. )
This species is represented in the collection by four small tubes that appear to have been attached to the dorsal valve of Wimanella simplex. The specimens are not very well preserved and it may be that they are the young or small tubes of H. annulatus (Matthew ).
Formation and locality—Middle Cambrian: (63j]) Ptarmigan formation; Ross Lake shale; outlet of cirque above and south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south- southwest of Stephen on Canadian Pacific Railway, British Columbia, Canada.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 27
HYOLITHELLUS HECTORI, new species Plate 5, fig. 1
This species is represented by a single specimen of a slender, rather thick tube, about 1 mm. in diameter, of which a portion 21 mm. in length is preserved. The tube has the form of the tube of Hyoli- thellus flagellum (pl. 5, fig. 4), but it is thicker and its surface is longitudinally ribbed by 24 or more narrow, sharp elevated lines or ribs ; exceedingly fine transverse striz of growth also occur between the crests of the ribs. A somewhat similar surface occurs on Hyolithes (Orthotheca) rosmarus Holm* and on Hyolithes cym- bium Holm.’
Formation and locality—Middle Cambrian: (35c) Ptarmigan formation ; Ross Lake shale, Albertella zone ; drift blocks of siliceous shale from the Ptarmigan formation, found on the south slope of Mount Bosworth, about 500 feet (152 m.) northwest of the Canadian Pacific Railway track between Stephen and Hector, eastern British Columbia, Canada.
HYOLITHES CECROPS, new species Plate 5, figs. 3, 3a-c
Shell nearly if not quite straight; the angle of divergence of the lateral borders from the median line is from 12 to 14 degrees. The dorsal side gently arched or nearly flat. Ventral side rising from the lateral borders to a rounded angle at the median line. The trans- verse section forms a triangle, with the base two or three times as great as the height. Surface of shell with very fine transverse strie and rather distinct lines of growth.
Dimensions.—A large shell has a length of 40 mm. with a breadth of the mouth of 16mm. Another has a length of 42 mm.; breadth at the mouth, 13 mm. A small shell, 15 mm. in length, has a breadth at the mouth of 8 mm., but it has been shortened and widened by distortion in the shale. The specimen 42 mm. long and 13 mm. wide at the mouth is probably the nearest to the original size of the shell.
Operculum.—The associated operculum is illustrated by figure 3c. Although the shells are abundant, only three specimens of the oper- culum have been found.
Observations —This species is uniformly larger than Hyolithes billingst of the Mount Whyte formation, and has a more triangular
*Sveriges Geol. Undersdkning, Ser. C, No. 112, 1893, Sv.-Kambrisk.- Siluriska Hyolithidz och Conularide, pl. 1, figs. 45, 46. * Idem, pl. 3, fig. 7.
28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
section. It differs from Hyolithes carinatus Matthew of the Stephen formation in absence of longitudinal ridges on the ventral side and also in its more triangular section.
Formation and locality—Middle Cambrian: Ross Lake shale member of Ptarmigan formation; (63j) outlet of cirque above and south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-southwest of Stephen on Canadian Pacific Railway; (63m) _ south slope of Mount Bosworth, about 500 feet (152.4 m.) above the Canadian Pacific Railway track, 1 mile (1.6 km.) east of Hector, 1.25 miles (2 km.) west of Stephen on the Continental Divide; (35c) drift boulder below locality 63m, all in British Columbia, Canada.
AGRAULOS STATOR Walcott Plate 6, fig. 6
Agraulos stator Watcott, 1916, Smithsonian Misc. Coll., Vol. 64, p. 173, pl. 36, fig. 6. (Described and illustrated.)
This very neat and fine species is quite abundant in some localities of the Ross Lake shale.
(63j]) Ptarmigan formation; Ross Lake shale; outlet of cirque above and south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south- southwest of Stephen on Canadian Pacific Railway; also (35c) drift blocks of siliceous shale from the Ptarmigan formation, found on the south slope of Mount Bosworth, about 500 feet (152 m.) northwest of the Canadian Pacific Railway track between Stephen and Hector, eastern British Columbia, Canada.
An apparently similar species as far as can be detenmniiel from the cranidium occurs in the limestone of the Chetang formation: (61w) gray, thin-bedded limestone; float rock in Terrace Creek, the head of which comes from Terrace Glacier, which joins Cole- man Glacier on the divide east of Chetang Cliffs. Terrace Creek enters Moose River about 6 miles (9.6 km.) below Moose Pass and 10 miles (16.1 km.) east-northeast of Robson Peak, northwest of Yellowhead Pass, eastern British Columbia, Canada.
PTYCHOPARIA CANDACE, new species Plate 6, figs. 3, 3a ¢
Dorsal shield —Dorsal shield rather small but strong. Axial lobe relatively broad, and doubtless strongly arched before compression ;
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 29 greatest width probably falling a little in front of the thorax and equal to a little less than two-thirds of the length.
Cephalon.—Cranidium only preserved. Glabella moderately large relatively, elongate trapezoidal; dorsal furrows moderately im- pressed, converging so rapidly that the width in front is but little more than half of that of the base; anterior extremity of the glabella broadly rounded or obscurely truncate ; glabellar furrows broadened or deepened by compression in the somewhat flattened cranidium figured ; posterior furrows oblique, posteriorly directed, medial pair somewhat cuneate, the anterior margin of the furrow at right angles to the axis of the shield, the posterior margin oblique ; anterior pair of furrows also cuneate but anteriorly directed, the lobe between the anterior and medial furrows with parallel sides at right angles to the axis; occipital furrow quite deeply impressed distally but almost obsolete upon the crest of the glabella; occipital ring expanded medially and bearing a rather large median node. Fixed cheeks low and quite broad, the distance from the palpebral lobe to the dorsal furrow more than half the width of the medial portion of the glabella ; postero-lateral lobe very broad, trigonal in outline, the distal extrem- ity tapering to an angle of about 45°; posterior groove broad but not very deep. Palpebral lobe very short, not very prominent, placed far forward opposite the anterior glabellar furrows. Palpe- bral ridge cordate, moderately elevated, cutting across the fixed cheeks almost at right angles to the shield, and intercepting the dorsal furrows about half-way between the anterior glabellar furrows and the anterior extremity. Frontal limb rather wide, probably evenly sloping before compression. Frontal border almost as wide medially as the medial portion of the limb and cut off from it by a shallow groove. Facial sutures angular, the posterior arm oblique, the anterior arm feebly convex; arc included between the facial sutures almost double the width of the base of the glabella. Free cheeks not preserved.
Thorax.—Thorax rather slender, tapering posteriorly. Thoracic segments 16 in number. Axial lobe flattened in the shale and rela- tively very broad, as a rule, decidedly more than half as wide as either of the pleural lobes; axial annulations conspicuously coarse. Pleural segments rather narrow, compactly arranged, obtusely angu- lated at the geniculation which falls about two-thirds of the distance from the axial furrow to the outer extremity ; pleural furrows broad and rather shallow for the most part, narrower and much deeper
30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
toward the distal extremity; ends of segments feebly inclined posteriorly and acutely falcate.
Pygidium.—Pygidium very short, only about one-eighth the length of the entire shield, rudely lenticular in outline. Axial lobe coarse, wider than either of the pleural segments, becoming increasingly lower posteriorly but persisting almost to the extremity ; axial annula- tions very obscure anteriorly, obsolete medially and posteriorly ; component segments probably 4 or 5 in number. ‘Pleural lobes trigonal, bearing traces anteriorly of an obscure grooving. Periph- eral rim not defined. Peripheral margin an arc of a little less than 180°.
Surface.—Surface ornamentation lost or undeveloped.
Dimensions.—Length of shield, 12.5 mm.; greatest width of shield, 8.0 mm.
Type locality —(4v) Gordon Creek, Powell County, Montana.
Observations—The elongate body, small pygidium and small palpebral lobe all suggest A graulos stator Walcott,’ but the cranidium is that of Ptychoparia and there are 16 thoracic segments, while A, stator has 22. P. candace appears to be a form that unites strong characters both of Agraulos and Ptychoparia.
It differs from Ptychoparia perola of the subjacent Mount Whyte formation of British Columbia in details of the cranidium and in its broader thoracic lobes; its glabella is more elongate, frontal limb deeper, palpebral lobe larger. The largest dorsal shield has a length of 20mm. A small dorsal shield 2.25 mm. in length has 1o thoracic segments and the cranidium indicates a narrowing of the elabellar lobe and widening of the fixed cheeks back of the palpebral lobes. The specimens occur in an argillaceous shale and do not retain the original surface characters. Ptychoparia candace is found in the Albertella fauna of Montana but not in that fauna in British Columbia. The genus is represented in the latter area by Ptycho- paria ? cilles, which is quite distinct.
Formation and locality—Middle Cambrian: (4v) Gordon shale; about 200 feet (61 m.) above the unconformable base of the Cambrian and 75 feet (22.9 m.) above the top of the quartzitic sandstones, Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River, Ovando quadrangle (U. S. G. S.), Powell County, Montana.
*Smithsonian Misc. Coll., Vol. 64, p. 173, pl. 36, fig. 6. See p. 28, and pl. 6, fig. 6, this paper.
NO.2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 31
PTYCHOPARIA ? CHARAX, new species Plate 6, fig. 1
Species known only from two cranidia.
Cephalon.—Glabella rather small relatively, not much more than - half as long as the cranidium, low, elongate, trapezoidal in outline, the front between one-half and two-thirds as wide as the base; dorsal furrows moderately impressed, evenly converging toward the broadly rounded anterior extremity; glabellar furrows rather broad and obscure, obsolete medially ; posterior pair somewhat oblique ; medial pair approximately horizontal; anterior pair indicated merely by very feeble depressions a little behind the anterior extremity ; occipital furrow rather broad but not very deep, approximately uniform in depth between the dorsal furrows; occipital ring not very wide, expanding medially, possibly bearing a small medial node. Fixed cheeks rather low, broad, the distance from the palpebral lobe to the dorsal furrow a little more than half as wide as the medial portion of the glabella ; postero-lateral lobe narrow, not very long, cuneate, acutely rounded at the distal extremity ; posterior groove broad and sharply defined excepting near the dorsal furrow, widest a little less than half-way from the inner to the outer extremity ; posterior margin of the lobe narrow, elevated, uniform in width; anterior margin of the groove acute, excepting along the inner third of its extent, rudely bisecting the outer cuneate portion of the lobe. Frontal limb and border not sharply differentiated from one another, upturned and slightly thickened along the outer rim; width of limb and border in front of the glabella about three-fifths the length of the glabella; profile gently concave medially, convexo-concave in front of the palpebral ridge. Palpebral lobe approximately one-half as long as the glabella, obliquely arcuate, quite prominently elevated, placed quite far back, so that the medial portion of the lobe is opposite the posterior glabellar furrows. Palpebral ridge not sharply differen- tiated from the lobe, cutting obliquely across the fixed cheeks from the anterior extremity of the lobe, and intercepting the dorsal furrows a little behind the anterior extremity of the glabella. Facial sutures irregular in outline, the posterior section oblique, the outer margin of the palpebral lobe asymmetrically arcuate and the anterior section conspicuously broad and evenly convex. Other characters not preserved.
Surface External surface shagreened with an exceedingly fine punctation.
32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
Dimensions—Length of cranidium, 9.6 mm. Length of glabella, 6.0mm. Width of anterior extremity of the glabella, 3.0mm. Width of base of the glabella, 5.0 mm.
Type locality—(4v) Gordon Creek, Montana.
Observations.—This is one of the Ptychoparia-like cranidia with a broad concave frontal border and rim that will undoubtedly be placed in a subgenus of Ptychoparia when the American species of the latter genus are clearly studied. The genus Agraulos is sug- gested, but that is forcing a form in that genus that apparently belongs elsewhere.
Formation and locality—Middle Cambrian: (4v) Gordon shale; about 200 feet (61 m.) above the unconformable base of the Cambrian and 75 feet (22.9 m.) above the top of the quartzitic sandstones, Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River ; and (4q) about 315 feet (96 m.) above the unconformable base of the Cambrian and 190 feet (57.9 m.) above the top of the quartzitic sandstones in a shale on the ridge between Gordon and Youngs Creeks, about half-way between Gordon Mountain and Cardinal Peak, both in Ovando quadrangle (U. S. G. S.), Powell me: Montana.
PTYCHOPARIA ? CILLES, new species Plate 6, fig. 2
Species known only from imperfect cranidia.
Cephalon.—Cranidium very strongly contoured. Glabella con- spicuously elevated, approximately two-thirds the length of the cranidium and as broad at the base as it is long ; medial section broad and obtuse, very gradually disappearing toward the anterior ex- tremity ; dorsal furrows very obscurely defined, converging so rapidly that the broadly rounded anterior extremity is only half as wide as the base; glabellar furrows sharply impressed upon the sides of the glabella but obsolete upon the crest; posterior pair cuneate, widening toward the crest, obliquely directed ; medial pair not quite so broad nor so oblique; anterior pair linear but deeply incised at right angles to the axis of the shield; occipital furrow rather broad, extending across the crest of the glabella but deepening toward the dorsal furrows; occipital ring imperfectly preserved, expanded medially, and probably of moderate width. Fixed cheeks rising abruptly to almost the level of the summit of the glabella, the slope from the dorsal furrow to the crest of the glabella very similar to the slope from the dorsal furrow to the palpebral lobe; postero-lateral
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 33
lobe almost if not quite as broad as it is long, obtuse at the outer extremity ; postero-lateral groove narrow toward the axis and in line with the occipital groove, broadening and deepening away from the axis. Palpebral lobe small but conspicuously high, arcuate, placed far forward opposite the lobe between the medial and anterior glabellar furrows. Palpebral ridge very narrow and rather obscure, forming an acute angle with the anterior extremity of the palpebral lobe, and slightly inclined posteriorly in crossing the fixed cheek so that it intercepts the dorsal furrows near the origin of the anterior glabellar furrows. Frontal limb narrow, feebly convex in front of the glabella and merging into the frontal border which is as wide or wider than the limb, and very strongly upturned so that the outline of the anterior portion of the cranidium is decidedly concave. Facial sutures following a sine curve from the genal angle along the anterior margin of the postero-lateral lobe to the eye lobe; anterior section of the suture more strongly convex than the posterior. A single imperfectly preserved free cheek, terminating in a rather short but acutely tapering spine, is associated with the cranidia.
Surface —External surface microscopically shagreened.
Dimensions.—Length of cephalon, 3.0 mm. Length of glabella, 2.0 mm.
Type locality—(63d) Ptarmigan formation; Ptarmigan Peak.
Observations —This small species is quite distinct from any other known to me. Its high eyes, concave frontal border and convex, strongly marked glabella distinguish it and also indicate a distinct subgenus or genus.
Formation and locality—Muiddle Cambrian: (63d) Ptarmigan formation ; dark, thin-bedded finely arenaceous limestone, east base of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line northeast of Lake Louise Station on the Canadian Pacific Railway, Alberta, Canada.
PTYCHOPARIA PYLAS, new species Plate 6, figs. 4, 4a-c
Dorsal shield—Dorsal shield rather small, elongate oval or cuneate in outline, doubtless quite strongly contoured before being com- pressed in the shale.
Cephalon.—Head shield exclusive of the genal spines approxi- mately one-third of the length of the dorsal shield, and a little less than twice as broad as it is long. Glabella angular, elongate- trapezodial in outline; only about half as wide at the anterior ex-
34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
tremity as it is at the base; dorsal furrows deeply impressed, inter- cepting the frontal furrow at an acute angle; glabellar furrows very obscure but persistent, in some individuals, across the crest of the glabella; posterior and medial pairs oblique and approximately parallel to one another, the anterior pair shorter, transverse to the axis, and in some individuals apparently undeveloped; occipital furrow broad and conspicuously deep, in most individuals, com- pletely isolating the occipital ring ; occipital ring similar in character to the anterior segments of the thorax, probably not spinose medially. Fixed cheeks quite wide and rather plump; postero-lateral lobe narrow, moderately produced, angulated at the outer extremity ; posterior groove narrow, deeply impressed, in line with the occipital furrow; posterior margin sharply elevated. Palpebral lobe large, conspicuously elevated, quite strongly crescentic. Palpebral ridge not sharply differentiated from the lobe as a rule, cutting across the fixed cheek almost at right angles to the axis and almost in line with the anterior furrow, and forming with the palpebral lobes and the anterior furrow of the glabella a rudely elliptical area. Frontal limb quite wide, evenly declining, or more frequently somewhat convex especially towards the sides. Frontal border moderately wide, not thickened, upturned, cut off from the limb by a shallow, ill-defined groove. Facial sutures roughly a spreading W with a broad arcuate base, a rather long, oblique, posterior limb and a rather short, convex, anterior limb. Free cheeks quite wide and smoothly inflated, the outer margin flattened and produced posteriorly into acutely tapering genal spines which terminate opposite the third thoracic segment. Thorax.—Thoracic segments probably 14 in number. Axial lobe quite prominent, moderately broad, cut off from the pleura by deep furrows. Pleural segments flexuous, even in the shale, obtusely angulated at the geniculation which falls, in the majority of indi- viduals, a little less than half-way from the proximal to the distal extremity ; pleural furrows very narrow and deeply incised, ‘sub- medial in position. Ends of segments cut away along the posterior margin, slightly inclined posteriorly, and acutely falcate. Pygidium.—Pygidium very small and very imperfectly known. Surface.—Character of external surface not preserved. Dimensions,—Length of dorsal shield, 4.7 mm. Greatest width of dorsal shield, 3.2 mm. Length of the cranidium of another indi- vidual, 6.5mm. Length of glabella, 4.0 mm. Type locality—(4q) Gordon Creek, Montana.
NO. 2 ALBERTELLA FAUNA IN. BRITISH COLUMBIA AND MONTANA 35
Observations.—This species is strongly characterized by its small pygidium, straight, deep pleural grooves on the thoracic segments, and broad frontal limb of the cranidium.
Formation of locality—Middle Cambrian: (4q) Gordon shale; about 315 feet (96 m.) above the unconformable base of the Cam- brian and 190 feet (57.9 m.) above the top of the quartzitic sand- stones in a shale on the ridge between Gordon and Youngs Creeks, about half-way between Gordon Mountain and Cardinal Peak, both in Ovando quadrangle (U.S. G.S.), Powell County, Montana.
CREPICEPHALUS CHARES, new species Plate 6, figs. 5, 5a-c
Species known only from a few imperfect cranidia and associated pygidia.
Cephalon.—Cephalon as restored from cranidium and free cheeks rather short and broad. Glabella a little less than two-thirds the length of the cranidium, low and moderately broad, rudely trape- zoidal in outline, elevated along an obscure medial ridge which gradually disappears toward the front; dorsal furrows not sharply defined, converging toward the squarely truncate anterior extremity with such rapidity that the front of the glabella is only half as wide as the base; glabellar furrows also rather obscure and, upon the crest of the glabella, entirely obsolete; posterior pair rather broad, obliquely directed ; medial and anterior pairs also rather broad and almost at right angles to the axis; occipital furrow of the same general character as the glabellar furrows, not very deep but mni- formly impressed throughout its extent; occipital ring of only moderate width, expanded medially and possibly obtusely angulated along the posterior margin. Fixed cheeks very low and broad, the distance from the palpebral lobe to the dorsal furrows more than half the width of the medial portion of the glabella; more strongly convex along the axis of the shield than at right angles to it ; postero- lateral lobe not preserved but necessarily narrow; groove in front of the posterior margin shallow toward the axis and in line with the occipital ring. Palpebral lobe imperfectly preserved, apparently short, crescentic, rather low and placed far back opposite the pos- terior lobe and furrow. Palpebral ridge cordate, moderately ele- vated, curving across the fixed cheek from the anterior extremity of the eye lobe and intercepting the dorsal furrows a little behind the anterior extremity of the glabella; palpebral ridges and lobes form- ing roughly a semi-ellipse interrupted by the glabella. Frontal limb
36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
moderately wide, gently convex. Frontal border almost as wide as the limb, gently concave. Facial sutures very imperfectly preserved. Associated free cheek rather narrow, smoothly convex; peripheral border very wide and flattened, terminating posteriorly in a rather short but acute spine.
Pygidium.—Associated pygidium rudely cordate in outline, exclu- sive of the posterior constriction, the length and breadth approxi- mately equal. Axial lobe not quite half as long as the caudal shield including the spines, but approximately two-thirds the length measured along the axis; limiting furrows not impressed, the lobe differentiated only by its low convexity and the rather obscure annula- tion; component segments apparently five in number including the terminal section. Pleural lobes somewhat flexuous, broadest a little in front of the median line, produced posteriorly into a pair of acute subspinose processes; margin between these tapering extremities sharply constricted. Pleural furrows ill defined; three or four shallow grooves usually developed parallel to the outer margin, least obscure anteriorly but on the posterior portion of the shield entirely obsolete. Peripheral margin very slightly raised anteriorly, not differentiated from the rest of the shield posteriorly.
Surface—Entire external surface crowded with a fine granula- tion; very sparse macroscopic granulation also developed on the cephalon and less so on the pygidium; granules most numerous and most regularly arranged upon the frontal border.
Dimensions.—Length of cephalon, 8.5 mm. Length of glabella, 5.0mm. Width of glabella at base, 4.6 mm. Length of pygidium, including spines, 5.6+ mm. Length of pygidium, excluding spines, 3.7mm. Breadth of pygidium, 5.6 mm.
Type locality —(63d) Ptarmigan formation; Ptarmigan Peak.
Observations—The most nearly related species appears to be Crepicephalus camiro Walcott.’ It differs from the latter in the details of form of the various parts of the cranidium and associated pygidium and in its granulated surface. C.camiro is from the Upper Cambrian of the southern Appalachian area and C. chares is from the Middle Cambrian of the Canadian Rocky Mountains.
The cranidium of C. cleora, a new species from the Mount Whyte formation, is much like that of C. camiro but differs in its wider frontal border and other details of the cranidium.
Formation and locality—Middle Cambrian: (63d) Ptarmigan formation; dark, thin-bedded finely arenaceous limestone, east base
* Smithsonian Misc. Coll., Vol. 64, 1916, p. 205, pl. 32, figs. 2, 2a.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 37
of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line northeast of Lake Louise Station on the Canadian Pacific Railway, Alberta, Canada. VANUXEMELLA NORTIA Walcott Plate 7, fig. 7
Vanuxemella nortia Wat.cott, 1916, Smithsonian Misc. Coll., Vol. 64, p. 222,
pl. 36, fig. 5. (Described and illustrated.)
Nothing has been added to our information of this species by recent collections.
Formation and locality—Middle Cambrian: (63j) Ptarmigan formation; Ross Lake shale; outlet of cirque above and south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south- southwest of Stephen on Canadian Pacific Railway, British Col- umbia ; and (35c) drift blocks of siliceous shale from the Ptarmigan formation, found on the south slope of Mount Bosworth, about 500 feet (152 m.) northwest of the Canadian Pacific Railway track between Stephen and Hector, eastern British Columbia, both in Canada.
OLENOPSIS cf. AMERICANUS Walcott
Plate 6, figs. 8, 8a-b
Olenopsis americanus WA.cottT, 1912, Smithsonian Misc. Coll., Vol. 57, p. 243,
pl. 36, figs. 8-11. (Description and illustration of species. )
Cranidia that appear to be identical with the cranidium of this species occur in association with Albertella helena in British Columbia, and the latter species is also associated with the type specimen of Olenopsis americanus in the Gordon shale of Montana.
Formation and locality —Middle Cambrian: (63j) Ptarmigan for- mation ; Ross Lake shale; outlet of cirque above and south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south- southwest of Stephen on Canadian Pacific Railway; also (35c) Albertella shale; drift blocks of siliceous shale from the Ptarmigan formation, found on the south slope of Mount Bosworth about 500 feet (152 m.) northwest of the Canadian Pacific Railway track between Stephen and Hector, eastern British Columbia, Canada.
The Montana locality of the type specimens of the species is (4v) Middle Cambrian ; Gordon shale; about 200 feet (61 m.) above the unconformable base of the Cambrian and 75 feet (22.9 m.) above the top of the quartzitic sandstones, in a shale which corresponds in stratigraphic position to shale No. 6 of the Dearborn River section,’
* Smithsonian Misc. Coll., Vol. 53, 1908, p. 202.
38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River, Ovando quadrangle (U.S. G. S.), Powell County, Montana.
ALBERTELLA BOSWORTHI Walcott Plate 7, figs. 2, 2a-b, 3, 3a-d
Albertella bosworthi WWaxcott, 1908, Smithsonian Misc. Coll., Vol. 53, p. 22, pl. 1, Ags. 4-7. (Description and illustration of the species.)
Albertella bosworthi Watcort, 1913, The Cambrian Faunas of China, Pub. No. 54, Carnegie Inst. of Washington, p. 105, pl. 12, fig. 2. (Figured on same plate with A. pacifica for purpose of comparison.)
The type specimen of this species was found in a drift boulder on the slopes of Mount Bosworth. Since 1908 entire specimens of the species have been found in situ on Mount Bosworth, also above Ross Lake south of Mount Bosworth and represented by fragments in the limestones of Castle Mountain, British Columbia, and in the Robson District of Alberta and British Columbia.
The specimens of the cranidium and pygidium from the limestones (figs. 3, 3b) are more convex and narrower than those from the shale in the Mount Bosworth area, owing to their not having been widened and distorted by compression as are the shale specimens.
Formation and locality—Middle Cambrian: Ptarmigan forma- — tion; Ross Lake shale; (63j) outlet of cirque above and south of © Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south- southwest of Stephen on Canadian Pacific Railway; (35¢) drift blocks of siliceous shale from the Ptarmigan formation, found on the south slope of Mount Bosworth, about 500 feet (152 m.) north- west of the Canadian Pacific Railway track between Stephen and Hector; also (63m) Ross Lake shale; south slope of Mount Bos- worth, about 500 feet (152 m.) above the Canadian Pacific Railway track, 1 mile (1.6 km.) east of Hector and 1.25 miles (2 km.) west of Stephen on Continental Divide, all in British Columbia, Canada.
At the locality 63m the species was found in thin layers of lime- stone interbedded in the shale: (58h) about 275 feet (85 m.) above the top of the Lower Cambrian in thin-bedded bluish-black limestone (272 feet=84 m.) forming 13 in Ptarmigan formation, Castle Mountain section ; just below the big cliff on the east shoulder of Castle Mountain, north of Canadian Pacific Railway, Alberta, Canada.
Also from (61p) Chetang formation; gray shaly limestone in massive beds; on northeast slope of Chetang Cliffs above Coleman Glacier Creek, 7 miles (11.2 km.) north-northeast in direct line from
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 39
summit of Robson Peak, northwest of Yellowhead Pass, western Alberta, Canada.
ALBERTELLA HELENA Walcott Plate 7, figs. 4, 5, 5a
Albertella helena Watcott, 1908, Smithsonian Misc. Coll., Vol. 53, p. 19, pl. 2, figs. 1-9. (Description and illustration of species.)
Albertella helena GraBau and SHIMER, 1910, North American Index Fos., Vol. 2, p. 274, fig. 1572c. (Characterized and figured.)
Albertella helena Waucott, 1913, The Cambrian Faunas of China, Pub. No. 54, Carnegie Inst. of Washington, p. 106, pl. 12, fig. 1. (Figured on same plate with A. pacifica for purpose of comparison.)
This species was described at length in 1908. Recent collections
have added very little to the information about it.
Formation and locality—-Middle Cambrian: (63j) Ptarmigan formation; Ross Lake shale; outlet of cirque above and south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south- southwest of Stephen on Canadian Pacific Railway; (35c) Drift blocks of siliceous shale from the Ptarmigan formation, found on the south slope of Mount Bosworth, about 500 feet (152 m.) north- west of the Canadian Pacific Railway track between Stephen and Hector; and (63m) Ross Lake shale; south slope of Mount Bos- worth, about 500 feet (152 m.) above the Canadian Pacific Railway track, I mile (1.6 km.) east of Hector and 1.25 miles (2 km.) west of Stephen on Continental Divide, all in British Columbia, Canada.
ALBERTELLA LEVIS, new species Plate 7, figs. 1, 1a
This species is represented by the cranidium and associated pygi- dium. The cranidium differs from that of A. bosworthi by its glabella being more expanded towards the front, much fainter glabellar furrows, relatively shorter palpebral lobes and almost smooth instead of finely granulated outer surface of the test. A minute median node occurs near the posterior margin of the occipital ring in both A. levis and A. bosworthi. .
The pygidium associated with the cranidia, also the cranidium and pygidium of A. bosworthi, in two blocks of limestone, are quite unlike the pygidia of typical Albertella, as the two spines emerge from the border at the postero-lateral margins and the pygidium is wider posteriorly and shorter. The axial lobe is narrow, strongly convex and with five segments and a terminal section; pleural lobes marked by three slightly impressed narrow furrows.
3
40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
Surface of cranidium and pygidium smooth except when a strong lens is used to bring out a very fine irregular, closely inosculating series of ridges.
The largest cranidium has a length of 7.5 mm.
Formation and locality—Middle Cambrian: (61p) Chetang for- mation ; gray shaly limestone in massive beds, on northeast slope of Chetang Cliffs above Coleman Glacier Creek, 7 miles (11.2 km.) north-northeast in direct line from summit of Robson Peak, north- west of Yellowhead Pass, western Alberta, Canada.
ZACANTHOIDES CHARILLA, new species Plate 6, figs. 9, 9a
Species known only from an imperfect cranidium and from two pygidia.
Cephalon.—Glabella large relative to the size of the cranidium, broadest anteriorly, gradually contracting toward the rather slender base, slightly expanding at the occipital ring, broadly and feebly arched, the curvature greatest a little in front of the median line; dorsal furrows quite deeply impressed, slightly concave, most strongly constricted opposite the posterior lobe; anterior extremity broadly arcuate; posterior glabellar furrows linear, converging toward the occipital groove, obsolete upon the summit of the glabella; medial glabellar furrows suggested by a very shallow and obscure depression extending across the glabella at right angles to the axis, about half way between the anterior extremity and the occipital ring; anterior glabellar furrows even more obscure than the medial, directed for- ward, but entirely obsolete upon the summit of the glabella ; occipital groove moderately wide, uniform in depth between the dorsal fur- rows; occipital ring quite wide and flattened. Fixed cheeks very much reduced; the area between the eye lobe and the dorsal furrow not much greater than the lobe; postero-lateral lobe very narrow, deeply furrowed in front of the posterior margin; outer extremity of lobe not preserved. Anterior limb very narrow and merging into the antero-lateral margin of the glabella; frontal limb obsolete, frontal border a narrow wire-like rim. Palpebral lobe very large, approximately half as long as the glabella, feebly arcuate, quite prominently elevated, cut off from the fixed cheek by a shallow groove; posterior extremity of the eye lobe opposite the posterior lobe of the glabella, the anterior extremity of the eye lobe intercept-
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 4I
ing the dorsal furrows at the origin of the anterior glabellar furrows. Other characters of the cephalon not preserved.
Pygidium.—Associated pygidium rather large for the cephalon, trigonal in outline, exclusive of the peripheral fringe of spines. Axial lobe decidedly wider than the pleural exclusive of their spinose annulations rather coarse, obscure only near the posterior extremity, indicating three component segments and a large terminal section. Pleural lobes very narrow, only the two anterior retaining any semblance to anchylosed segments of the thorax; extremities of extremities, prominently elevated, acutely tapering posteriorly; segments attenuated and spinose, the spines drooping posteriorly and approximately parallel; second spine from the thorax the longest of all, the third nearly in line with it; four shorter subequal spines included between these two pairs.
Surface——External surface smooth under low magnification but minutely roughened by very fine, irregular anastomosing ridges when examined with a strong lens.
Dimensions.—Length of glabella, 3.5 mm. Breadth of glabella in front, 2.7mm. Breadth of glabella at base, 1.5 mm.
Type locality.—(610) Middle Cambrian: Chetang formation; Chetang Cliffs, 7 miles (11.2 km.) north-northeast of Robson Peak.
Observations.—This species recalls at once Zacanthoides idaho- ensis. It is closely allied to it but differs in its narrower antero- lateral limb of the fixed cheek, shorter palpebral lobe, and apparent absence of the frontal limb. The associated pygidium differs in the size and arrangement of the spines of the flattened border.
Formation and locality —Middle Cambrian: (610) Chetang for- mation ; gray shaly limestones in massive beds ; on northeast slope of Chetang Cliffs above Coleman Glacier Creek, 7 miles (11.2 km.) north-northeast in direct line from summit of Robson Peak, north- west of Yellowhead Pass, western Alberta, Canada.
ZACANTHOIDES ? CIMON, new species
Plate 7, figs. 6, 6a
Species known only from imperfect cranidia and fragments of a pygidium.
Cephalon.—Cranidium rather small. Glabella very long relatively, more than nine-tenths the length of the cranidium, but not quite twice as broad as its length, broadly and quite prominently elevated medi- ally, very feebly constricted laterally but expanding anteriorly, both in
42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
the direction of the axis and at right angles to it; glabellar furrows
_rather broad and shallow, cutting up the glabella into obscure annula-
tions which are perceptible even upon the crest of the glabella ; occipi- tal furrow moderately broad, uniform in depth between the dorsal furrow ; occipital ring rather low, broad, expanded medially and pos- sibly nodose. Fixed cheeks exclusive of the postero-lateral lobe appearing as semielliptical extensions on either side of the medial posterior portion of the glabella; greatest width of the fixed cheek, exclusive of the postero-lateral lobe which has not been preserved, rarely more than half the width of the medial portion of the glabella. Palpebral lobe and ridge not differentiated, the two together forming a cordate, strongly arcuate ridge with one extremity near the occipital ring, the other directly in front of the anterior glabellar furrows, the ridge cut off from the fixed cheek by a clearly defined groove ; medial portion of the palpebral arc nearly in line with the posterior glabellar furrows. Frontal limb obliterated medially. Frontal border very narrow, upturned, probably somewhat thickened. Facial sutures imperfectly preserved, the anterior section apparently . diverging rapidly from the anterior extremity of the palpebral arc. Free cheeks not preserved.
Pygidium—Pygidium known only from a couple of proximate, parallel, caudal spines attached to the peripheral rim and connected with a fragment of the axial lobe.
Surface —External surface microscopically shagreened.
Dimensions.—Length of cranidium, 6.2 mm. Length of glabella, 5.7mm. Width of medial portion of glabella, 3.2 mm.
Type locality —(63b) Ptarmigan Peak, Alberta, Canada.
Observations.—The two caudal spines which have been preserved were probably about 10 mm. long before the loss of their tips. They are exactly parallel to one another and separated by a space no greater than the width of one of the slender spines.
The cranidium and the fragment of the associated pygidium both suggest Zacanthoides, but as the cranidium might possibly belong to a species of Albertella the generic reference is tentative. I do not know of a similar described form of cranidium or pygidium.
Formation and locality—Middle Cambrian: (63b) Ptarmigan formation; bluish-black, more or less finely arenaceous limestone in layers 0.5 to 8 inches thick that form massive layers 450 feet (138 m.) thick beneath the great Cathedral limestone ; east base of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line northeast of Lake Louise station on the Canadian Pacific Railway, Alberta, Canada.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 43
_ZACANTHOIDES CNOPUS, new species Plate 6, figs. Io, Toa
Species known only from an imperfect cephalon and a portion of the thorax.
Dorsal shield.—Dorsal shield rather small for the group, elongate- oval in outline. Axial lobe convex, strong, as wide as the pleura exclusive of the spinose extremities and elevated high above them even in the shale.
Cephalon.—Cephalon apparently a little less than one-third of the length of the dorsal shield, and about twice as broad as it is long. Cranidium exclusive of the postero-lateral lobes somewhat pitcher- shaped, broadly convex medially and posteriorly, flaring anteriorly. Glabella rather low but relatively long, expanding slightly anteriorly both with the axis and at right angles to it, broadly and very feebly constricted medially ; dorsal furrows not very deeply impressed and, between the posterior glabellar furrows and the occipital ring, almost obsolete; anterior furrow also shallow, broadly arcuate; glabellar furrows quite pronounced; posterior pair oblique, quite deeply gouged toward the dorsal furrows but obsolete upon the subangular crest of the glabella; medial pair similar in general character to the posterior but shorter and less oblique; anterior pair reduced to very obscure, lateral depressions at some little distance behind the anterior extremity ; occipital furrow deeply incised distally but broad and shallow upon the summit of the glabella; occipital ring low and broad, expanded medially and bearing near the posterior margin traces of an occipital node. Fixed cheeks narrow, the distance from the palpebral lobe to the dorsal furrow less than half the width of the glabella, auriculate in outline, exclusive of the postero-lateral lobe ; postero-lateral lobe not preserved but doubtless very slender, and probably petaloid. Palpebral lobe and palpebral ridge not differentiated, the two together forming a cordate, sickle-shaped ridge with one extremity near the occipital ring, the other directly in front of the anterior glabellar furrows but at some little distance behind the anterior extremity of the glabella; palpebral lobe and ridge cut off from the cheek by a narrow deeply incised groove. Frontal limb narrow, flattened, but little wider than the cordate frontal border. Free cheeks wide and probably rather low, periph- eral bofder abruptly constricted and produced posteriorly into very slender, acutely tapering spines which apparently terminate opposite the fourth thoracic segment.
44 SMITHSONIAN MISCELLANEQUS COLLECTIONS VOL. 67
Thorax.—Thoracic segments eight or nine in number, probably nine. Axial lobe very coarse, wider than the pleural lobes and strongly convex; annulations sharply defined and bearing a medial node, probably indicating the former presence of a medial spine; the slender spine upon the seventh thoracic segment still preserved, prob- ably about 10 mm. long, or more than half the length of the dorsal shield. Pleural segments, exclusive of the attenuated spinose ex- tremities, very short; pleural furrows broad, almost as wide as the including segment and moderately deep; extremity of first thoracic segment apparently not spinose; extremity of second thoracic seg- ment attenuated, posteriorly inclined and produced into a slender spine a little longer than the unflexed portion of the segments; extremities of the medial and posterior thoracic segments between two and three times the length of the rest of the segment, strongly inclined posteriorly.
Pygidium.—Pygidium not very well preserved, short. Axial lobe relatively large and strong, obtusely truncate posteriorly; caudal annulations almost as prominent as those of the thorax, four in number with a terminal section. Pleural lobes of the pygidium not preserved except the spinose extensions of the pleura which extend backward approximately parallel to the axis of the shield, and almost twice the length of the axial lobe.
Surface.—Character of external surface not preserved ; surface of spines covered with a microscopically fine lacy venation.
Dimensions—Length of dorsal shield, 13.5+ mm. Length of cephalon, 4.0+ mm. Greatest width of thorax, including the spinose extremities, 11.0+ mm. Greatest width of thorax, excluding the spinose extremities, 6.0 mm.
Type locality—(4v) Gordon Creek, Montana.
Observations.—The cranidium of this species is much like that of Z. idahoensis, but the thorax has the great median spine on the eighth segment instead of the fifth and the spinose extensions of this pleura are relatively longer. The imperfection of the specimens prevents closer comparison. Zacanthoides cnopus differs from Z. typicalis and Z, spinosus very much as Z. idahoensis differs from them.’
Formation and locality—Middle Cambrian: Gordon shale; (4v) about 200 feet (61 m.) above the unconformable base of the Cam- brian and 75 feet (22.9 m.) above the top of the quartzitic sandstones,
*Smithsonian Misc. Coll., Vol. 53, 1908, pl. 3, figs. 1-11. * Tdem, p. 20.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 45
Gordon Creek, 6 miles (9.6 km.) from South Fork of Flathead River, Ovando quadrangle (U.S. G. S.), Powell County Montana.
NEOLENUS CONSTANS, new species Plate 6, figs. 7, 7a
Species known only from a single caudal shield.
Pygidium.—Pygidium large and coarse, roughly semielliptical in outline, about four-fifths as long as it is broad ; component segments five in number including the terminal section. Axial lobe elongate- conic in outline, almost as broad anteriorly as one of the pleural lobes, evenly tapering toward the sharply rounded posterior ex- tremity of the lobe; annulations distinct, becoming less prominent and more closely spaced posteriorly. Lateral lobes strongly convex ; segments feebly anchylosed especially toward the thorax; pleural furrows broad and, toward the posterior extremity, obscure, arcuate anteriorly, approximating more and more closely to the axis of the shield posteriorly ; outer extremities of segments discrete and falcate or even semispinose. Peripheral rim not very sharply defined, out- lined by the flattening of the shield and by a series of shallow pits which mark the terminations of the pleural furrows; outer margin serrated by four broad-based, rather short spines quite sharply con- cave opposite the extremity of the axial lobe.
Surface —External surface finely punctate, having the appearance under high magnification of having been very finely etched with acid.
Dimensions.—Length of caudal shield, 20+ mm. Greatest breadth of caudal shield, 25.0+ mm.
Type locality—(63b) Ptarmigan Peak, Alberta, Canada.
Observations —Although the extremity of the axial lobe is sharply defined, there is a very obscurely elevated cuneate area extending backward from the extremity and wedging out at the margin.
I do not usually like to found a species on a pygidium, but this form is so distinct and strong that it seems worthy of such recogni- tion. It differs from the pygidium of Neolenus serratus in having one less pair of border spines, one less pleural segment indicated on the pleural lobes, and a relatively shorter, broader axial lobe.
Formation and locality——Middle Cambrian: (63b) Ptarmigan formation ; bluish-black, more or less finely arenaceous limestone in layers 0.5 to 8 inches thick that form massive layers 450 feet (138 m.) thick beneath the great Cathedral limestone ; east base of Ptarmigan Peak 5.5 miles (8.8 km.) in an air line northeast of Lake Louise Station on the Canadian Pacific Railway, Alberta, Canada.
46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
BATHYURISCUS ROSSENSIS, new species Plate 5, figs. 5, 5a-d Bathyuriscus (Poliella) sp. undt. Watcort, 1916, Smithsonian Misc. Coll., Vol. 64, No. 5, p. 355, pl. 46, fig. 7. (Described and illustrated.)
Dorsal shield—Dorsal shield a very smooth elongated oval, the greatest breadth in the type less than two-thirds of the length. Axial lobe well differentiated, moderately convex ;. pleura flattened in the shale but retaining traces of rather a strong downward flexure at the genal angle.
Cephalon.—Cephalon, exclusive of the genal spines, about two- fifths as long as the entire dorsal shield, strongly contoured even in the shale. Glabella quite low, almost as long as the cephalon, strictly clavate in outline; dorsal furrows distinct, deepening anteriorly ; anterior extremity expanded and broadly arcuate; posterior lateral furrows rather broad and deeply intrenched, directed backward at an angle of approximately 45° but evanescing abruptly before reach- ing the medial line; other lateral furrows obsolete ; occipital ring distinct, trigonal ; occipital furrow deeply gouged toward the distal extremities but shallow and rather ill defined upon the crest of the glabella ; occipital ring posteriorly produced and sharply angulated, and bearing a short acute spine at the apex of the angle. Fixed cheeks lower than the glabella, rather wide relatively, the distance from the palpebral lobe across to the dorsal furrow a little more than half the width of the medial portion of the glabella; postero-lateral lobes very narrow and petaloid ; groove behind the posterior margin very broad, especially toward the outer extremity. Palpebral lobe narrow, strongly crescentic, about one-third as long as the glabella, set so far back that the posterior extremity of the lobe is almost in line with the occipital furrow. Palpebral ridge often rather obscure, arching obliquely across from the anterior extremity of the palpebral lobe and intercepting the dorsal furrow about half-way between the outer extremity of the posterior lateral furrow and the anterior extremity of the glabella. Facial sutures conspicuously sinuous, fol- lowing along the low arch of the postero-lateral lobes of the fixed cheeks, around the strongly convex palpebral lobe and the shorter but almost equally convex anterior lobe; arc included between the extremities of the facial sutures approximately one-third the peri- phery of the cephalon exclusive of the genal spines.
Free cheeks of about the same width as the fixed cheeks, but more plump, bearing short and rather broad infragenal spines and very long, slender acute, scimiter-like genal spines which lie close to the
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 47
outer extremities of the thoracic segments and are produced back- ward at least as far as the pygidium. Frontal border very narrow anteriorly, widening slightly laterally.
Thorax.—Thoracic segments moderately wide, eight in number. Axial lobe not quite so wide as the pleura and arched well above them ; distal extremities of the axial segments produced into falcate extremities about one-third as long as the pleural segments which they overlie; medial portion of the axial segment probably elevated into an obtuse node. Pleural segments doubtless rather strongly flexed at their falcate outer extremities ; pleural furrows broad and quite deep, much more steeply channeled along the anterior margin than along the posterior, gradually disappearing distally ; outer ex- tremities of the pleura acute and posteriorly directed, rounded aw ay along the underlapping anterior margin.
Pygidium.—Pygidium quite large, contained between three and four times in the length of the shield, sharply differentiated from the thorax ; axial lobe of the pygidium subcylindrical, relatively slender, abruptly evanescing at some little distance in front of the posterior extremities ; included segments probably five in number, annulations obsolete posteriorly but strongly defined anteriorly, that in front and often the next behind it bearing an acute spine. Lateral furrows broad and rather ill defined, approximately parallel, and inclined at an angle of about 45° to the axis of the shield. Anterior segment of the fused portion of the pygidium produced into a rather short, posteriorly directed spine. Periphery of pygidium indented at the caudal spine, squarely truncate or broadly constricted posteriorly.
Surface ——There is very little trace of an external sculpture except- ing upon the genal spines which are longitudinally striated with very fine anastomosing groovings. One cranidium, however, is sha- greened with rather a coarse granulation and on this same individual there are traces of three pairs of short, horizontal glabellar furrows in front of the oblique posterior pair.
Dimensions —Length, 49.5 mm. Maximum width, 35.0 mm. Length of cranidium, 21.0mm. Length of pygidium, 13.0 mm.
Type locality—(63}) Ptarmigan formation, Albertella shale zone ; above Ross Lake, British Columbia, Canada.
Observations.—B. rossensis Walcott is, perhaps, best characterized by the very much produced genal spines. They certainly extend as far back as the pygidium and their attenuated extremities may persist even to the posterior margin of the shield. There is a strong tendency in this species toward the development of spines and nodes.
48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
There are infragenal as well as genal spines developed, and the occi- pital ring and the axial ring both of the thorax and the pygidium are nodulated. The triangular axial extensions in the pleural grooves so characteristic of the genus are unusually well developed in this species. The glabella is broad relatively, and only the posterior lateral furrows are perceptible on the majority of the individuals. The caudal shield is moderately large but less strongly annulated and furrowed than in the majority of Bathyuriscus. The number of thoracic segments is the same in the half-dozen individuals in which the complete shields have been preserved.
The pygidium of B. adeus’* has a somewhat similar marginal spine on each side, but otherwise the pygidia differ in many details. The cranidium of B. belesis* is very similar but the associated pygidia are quite dissimilar.
The pygidium described and illustrated as Bathyuriscus (Poliella) sp. undt. I ° is now referred to this species. The two specimens then known of were broken along the outer border and did not show the spine on each side. By error the locality of the specimens was given as 35e. They came from 35c as defined below.
In the collection made by Dr. Frank D. Adams and Mr. W. J. Dick, 4 miles (6.4 km.) north of North Kootenay Pass, Alberta, there are specimens of large species of Bathyuriscus that are appar- ently identical with B. rossensis. They occur on the surface of very thin layers of bluish-gray limestone in association with a typical Albertella fauna as follows:
Agraulos stator Walcott Vanuxemella nortia Walcott
Albertella bosworthi Walcott Asaphiscus rossensis Walcott
Formation and locality—Middle Cambrian: (63j) Ross Lake shale member of the Ptarmigan formation ; outlet of cirque above and south of Ross Lake on north slope of Popes Peak, 1.5 miles (2.4 km.) south-southwest of Stephen on Canadian Pacific Railway; (63m) Albertella zone; south slope of Mount Bosworth, about 500 feet (152.4 m.) above the Canadian Pacific Railway track, 1 mile (1.6 km.) east of Hector and 1.25 miles (2 km.) west of Stephen on Conti- nental Divide; and (35c) also Albertella zone; drift blocks of silice-
* Smithsonian Misc. Coll., Vol. 64, 1916, pl. 47, figs. 3, 3b. ? Idem, p. 338, pl. 50, figs. 1, 1D. *Idem, p. 355, pl. 46, fig. 7.
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 49
ous shale from the Ptarmigan formation, found on the south slope of Mount Bosworth about 500 feet (152.4 m.) northwest of the Canadian Pacific Railway track between Stephen and Hector, all in British Columbia, Canada.
Also 4 miles (6.4 km.) north ef North Kootenay Pass, Alberta, Canada. Specimens in Museum of McGill University, Montreal.
BATHYURISCUS cf. ROSSENSIS, new species Plate 5, figs. 6, 6a
Cephalon.—Cranidium large and strongly contoured. Glabella long and relatively narrow, somewhat clavate in outline, slightly expanded anteriorly both along the transverse and the longitudinal axis, the maximum elevation falling in front of the transverse median line; glabellar furrows obscure in the majority of individuals, the posterior pair rather broad and very strongly oblique, the pair in front of them approximately horizontal or feebly inclined posteriorly, the two anterior pairs very slightly inclined anteriorly ; occipital fur- row broad but not very deep, persisting across the crest of the glabella; occipital ring rather wide, cuneate, the posterior margin produced, acutely ridged and angulated and bearing an obtuse spine at the apex of the angle; dorsal furrows moderately impressed, broad and feebly constricted medially, in the majority of individuals more strongly divergent anteriorly than posteriorly; anterior ex- tremity of the glabella broadly arched. Fixed cheeks low, rather broad relatively, the distance from the palpebral lobe across to the dorsal margin approximately half the width of the medial portion of the glabella; postero-lateral lobe narrow but produced laterally ; posterior furrow broad, oblique, its anterior margin in line with the oblique posterior margin of the occipital ring; palpebral lobe moderately wide, reniform, about three times the length of the glabella, the median transverse line of the lobe falling a little behind the median transverse line of the glabella; palpebral ridge obscure in the majority of individuals, arching across from the palpebral lobe and intercepting the dorsal furrows at or a little in front of the next to the anterior pair of lateral furrows. Facial sutures outlined as in figure, the anterior limb broadly arched. Character of free cheeks not known.
Surface—Smooth or slightly roughened by obscure granulation.
Dimensions.—Length of cranidium, 30.0mm. Length of glabella, 28.5 mm.
* Smithsonian Misc. Coll., Vol. 53, No. 5, 1908, p. 214.
50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
Type locality—(63m’) Mount Bosworth, British Columbia, Canada.
Observations.—This form is known only from cranidia and pygidia occurring in thin limestone lentiles in the shale with B. ros- sensis. The glabella is longer and more slender proportionally than that of rossensis. These differences are apparently too great to be due to individual variation, or to compression and distortion. The glabelle of Bathyuriscus sp. are strongly convex and on some speci- mens the median ridge is strongly defined, especially toward the anterior portion.
The associated pygidia are closely related if not identical with those of B. rossensis except that the limestone form is narrower and more elongate proportionally.
Formation and locality—Middle Cambrian: (63m’) Ptarmigan formation (Ross Lake shale) ; thin lentiles of limestone included in the shale ; south slope of Mount Bosworth, about 500 feet (152.4 m.) above the Canadian Pacific Railway track, 1 mile (1.6 km.) east of Hector and 1.25 miles (2 km.) west of Stephen on Continental Divide, British Columbia, Canada.
BATHYURISCUS (POLIELLA) CHILO, new species Plate) 5, fe. 4
Dorsal shield —Dorsal shield rather small, quite slender, elongate- — oval in outline, the greatest width, exclusive of the free cheeks which have not been preserved, a little more than half the length. Axial lobe relatively broad in all three divisions of the shield and con- spicuously elevated above the flattened pleura.
Cephalon.—Cephalon more than one-third the length of the dorsal shield. Glabella large relatively, rather tumid, subrectangular in outline, expanding very slightly near the front ; dorsal furrows feebly impressed, rudely parallel excepting near the anterior extremity where they tend to diverge ; front of glabella ill defined, very broadly
and very feebly arcuate; glabellar furrows obscure, the posterior
pair oblique, the medial and anterior pairs more nearly transverse ; occipital furrow shallow; occipital ring imperfectly preserved, ap- parently rather wide and similar in character to the anterior segments of the thorax. Fixed cheeks imperfectly known, apparently rather wide and broadly convex, the distance from the palpebral lobe to the dorsal furrow more than half the width of the medial portion of the elabella ; postero-lateral lobe narrow, short, obtusely petaloid at its extremity ; posterior groove not very deep, in line with the occipital
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 51
ring; margin behind the groove increasingly wide away from the axis. Palpebral lobe conspicuously elevated and not differentiated from the palpebral ridge which cuts obliquely across the fixed cheek and intercepts the dorsal furrows near the origin of the posterior -glabellar furrows; raised margin of the lobe probably cut off from the surface of the cheek by a broad and rather deep furrow. Other characters of the cephalon not preserved.
Thorax.—Thoracic segments nine in number. Axial lobe strongly convex, broader than the pleural lobes. Pleura short, the anterior medial segments the most produced ; pleural furrows rather shallow, almost as wide as the including segment ; extremities of the anterior and medial segments apparently obtuse ; last three segments in front of the caudal shield acutely falcate distally.
Pygidium.—Pygidium short, rudely lenticular in outline. Axial lobe, strongly convex, relatively broad, subcylindrical, tapering slightly toward the broadly rounded posterior extremity ; annulations distinct but not conspicuous, indicating two component segments and a terminal section. Pleural lobes somewhat flexuous, of approxi- mately the same width as the axial; pleural grooving very obscure, rudely parallel to the anterior margin. Peripheral rim narrow, smooth, flattened, broadly arcuate.
Surface —External surface microscopically shagreened.
Dimensions.—Length of dorsal shield, 12.5+ mm. Greatest width of dorsal shield, exclusive of the fixed cheek, 7.+ mm.
Type locality—(63n) Ptarmigan formation; Wonder Pass, west of Gog Lake, British Columbia, Canada.
Observations —When in the field I referred this species to B. (P.) sylla* of the Chetang formation, but comparison with the type specimen of the latter showed that they differed in the nearly straight sides of the glabella and narrower and shorter associated pygidium. The most ‘nearly related species appear to be B. (P.) primus and B. (P.) anteros* from which it differs in many details.
Formation and locality—Middle Cambrian: (63n) Ptarmigan ? formation; bluish thin-bedded limestone northwest side of Wonder Pass at east base of ridge west of Gog Lake, on Continental Divide, in British Columbia, 19 miles (30.4 km.) southwest of Banff, Canada.
1 Smithsonian Misc. Coll., Vol. 64, 1916, p. 354, pl. 48, figs. 3, 3a-e. * Idem, pl. 46, figs. 5, 6, 6a-c.
4
52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
DESCRIPTION OF PLATE 4
Tholsastercila ? Jrindet. Walcott. ov. .). «ce. sous oss oslo oe ee eee 25 Fic. 1. (X2.) <A six-rayed spicule showing a central nodule. U. S. National Museum, Catalogue No. 63711. (63i.) 1a. (X6.) Central portion of the disk of fig. 1 enlarged to show structure.
Bocystites’? sp*undt. 2.2. cde ete: os aoe oe ee Eee 25 Fic. 2. (Natural size.) The only specimen known to me of this form. U. S. National Museum, Catalogue No. 63712.
The specimens represented by figs. I, Ia, and 2 are from (Locality 63j) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake, British Columbia.
Micromstra (Patertma) wapta Walcott. .......0. 3s. ok eee oe 25 Fic. 3. (X2.) Exterior of ventral valve. The type specimen (U. S. National Museum, Catalogue No. 51402a). The figure 3 is copied from Walcott, Smithsonian Misc. Coll., Vol. 53, 1908, pl. 7, fig. 6. Also Monogr. 51, U. S. Geol. Surv., 1912, text fig. No. 29A, p. 357.
The specimen represented is from (Locality 35c) Middle Cam- brian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth, British Columbia.
Obolus. paruus Walcott Ho2c5 fn ne ee ee ee 25 Fic. 4. (X 4.) Exterior of a ventral valve, the type specimen (U. S. National Museum, Catalogue No. 51400a). 4a. (X4.) Exterior of a dorsal valve. U. S. National Museum, Catalogue No. 51400b.
The specimens represented by figs. 4 and 4a are copied from Wal- cott, Smithsonian Misc. Coll., Vol. 53, 1908, pl. 7, figs. 10, toa. Also Monogr. 51, U. S. Geol. Surv., 1912, text figs. 37A and 37B, p. 408.
The specimens represented are from (Locality 35c) Middle Cam- brian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth, British Columbia.
Acrothele collenst Walcott \. 5 :oica% since Sols daciecichls melee eis ae ves Fic. 5. (X4.) A large ventral valve. U.S. National Museum, Cata-
logue No. 51410c.
5a. (X4.) Broken ventral valve showing false area. U. S. National Museum, Catalogue No. 51410b.
5b. (X4.) Cast of a ventral valve showing the incurving of the growth lines across the false area. U.S. National Museum, Catalogue No. 514104.
5c. (X4.) Exterior of a dorsal valve. U. S. National Museum, Catalogue No. 51410e.
The figures 5, 5a-c are copied from Walcott, Monogr. 51, U. S. Geol. Surv., 1912, text figs. 55, B, C, D, and E, p. 641.
The specimens represented are from (Locality 35c) Middle Cam- brian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth, British Columbia.
sd, sd’. (X 4.) Top and back views of the posterior portion of a ventral valve. U. S. National Museum, Catalogue No. 519730.
Se. (X4.) Side view of the type specimen, a ventral valve. U.S. National Museum, Catalogue No. 51973a.
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 2, PL. 4
SPONGE, CYSTID, AND BRACHIOPODS
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA
53
Acrothele colleni Walcott—Continued. PAGE
sf. (X 2.5.) Exterior of a dorsal valve with the cardinal slopes rounded in by pressure. An imperfect valve beside it has the outline of figure 5c. U. S. National Museum, Cata- logue No. 51973c.
The figures 5d, 5e, and 5f are copied from Walcott, Monogr. 51, U. S. Geol. Surv., 1912, pl. 63, figs. 6, 6a, 6b.
The specimens represented are from (Locality 4q) Middle Cam- brian: Gordon shale near Gordon Mountain, Ovando quadrangle (US: G: S.), Montana.
Dera emnies. Walcott’. 7 . Se 2a Aion aiid ea oa cies eels eo bee Fics. 6, 6a. (Natural size.) Ventral valves of varying outline owing to distortion in the shaie. U.S. National Museum, Cata- logue Nos. 52277a and 52277). 6b. (Natural size.) Cast of interior of a ventral valve. U. S. National Museum, Catalogue No. 52277d. 6c. (X2.) Ventral and dorsal valves compressed and resting against each other at the posterior margins. U.S. National Museum, Catalogue No. 52278b.
The figures 6, 6a-c are from Walcott, Monogr. 51, U. S. Geol. Surv., 1912, pl. 80, figs. 2a, 2b, 2c, 2e.
The specimens represented are from (Locality 4w) Middle Cam- brian: Gordon shale on Youngs Creek, Ovando quadrangle (U. S. G. S.), Montana.
7, 7a. (X2.) Ventral valves of varying outline owing to dis- tortion in the shale. U. S. National Museum, Catalogue Nos. 63713 and 63714. (63j.) 7b. (X2.) Cast of interior of a dorsal valve. U. S. National Museum, Catalogue No. 63715. (63i.) 7c. (X3.) Interior of a compressed dorsal valve. U.S. National Museum, Catalogue No. 51407. This figure is from Wal- cott, Monogr. 51, U. S. Geol. Surv., 1912, text fig. No. 64, p. 748. The specimen represented by 7c is from (Locality 35c) Middle Cambrian: Ptarmigan formation (Ross Lake shale): Mount Bos- worth, British Columbia.
8. (X2.) Cast of two ventral valves in limestone. U. S. National Museum, Catalogue No. 63716. (63m.)
8a. (X 3.) Exterior of a ventral valve. U.S. National Museum, Catalogue No. 63717. (63m.)
8b. (X3.) Area of a ventral valve. U. S. National Museum, Catalogue No. 63718. (63m.)
8c. (X2.) Exterior of a dorsal valve. U. S. National Museum, Catalogue No. 63719. (63m.)
The specimens represented by figs. 7, 7a-b are from siliceous shale (Locality 63j), Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake; and figs. 8, 8a-c from limestone interbedded in the shale of locality 63m, Middle Cambrian: Ptarmi- gan formation; Mount Bosworth, both in British Columbia.
NESTE SACERCHMICELU CAGE Ge NV AL COLE. <1 chard oeetmetetere o e IOE r re ot arin Sk ota soe Sielele otiee sts Fic. 9. (X 3.) Imperfect exterior of a small ventral valve. U. S. National Museum, Catalogue No. 63720.
The specimen represented by fig. 9 is from _ limestone (Locality 61.0), Middle Cambrian: Chetang formation; Robson District, Alberta.
26
26
54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
DESCRIPTION OF PLATE 5
AHyohthellus hectori, Walcott..a6 epic. . .coen coco ee ee eee oe eee Fic. 1. (X8.) Section of a tube enlarged to show surface charaniaee U. S. National Museum, Catalogue No. 63721.
The specimen represented is from (Locality 35c) Middle Cam- brian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth, British Columbia.
yivolthellus flagellum (Matthew) ........055-0 500 ce e0c cesses eee Fic. 2. (X 3.) A long curved tube. U. S. National Museum, Cata- logue No. 63722. The figure 2 is the same as fig. 8, pl. 1,
Walcott, Canadian Alpine Journ., Vol. 1, 1908.
From (Locality 14s) Middle Cambrian: Stephen formation; Mount Stephen, British Columbia.
2a. (X4.) A group of four small tubes attached to a valve of Wimanella simplex. U. S. National Museum, Catalogue No. 63723.
From (Locality 63)) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake, British Columbia.
Hyoltthes cecrops Walcott). 0% oc. 0 viele ss an pa eee Oo aa eee Fic. 3. (Natural size.) Dorsal view with shell broken away. The type specimen. U. S. National Museum, Catalogue No. 63724. 3a. (X4.) Ventral view of a small specimen that is only slightly compressed. U.S. National Museum, Catalogue No. 63725. 3b. (Natural size.) Dorsal view of a small wide specimen flattened in the shale. U.S. National Museum, Catalogue No. 63726. 3c. (X2.) Inner side of an operculum associated with the speci- men illustrated by figs. 3, 3a-b. U. S. National Museum, Catalogue No. 63727. The specimens represented by figs. 3, 3a-c are from (Locality 631) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake, British Columbia.
Bathyuriscus (Poltella) chilo. Walcott. ....: v.52. - one -e ee Fic. 4. (X 3.) Small dorsal shield a little injured by weathering. U. S. National Museum, Catalogue No. 63728.
From limestone (Locality 63n), Middle Cambrian: Ptarmigan formation: Wonder Pass, British Columbia.
Bathyuriscus rossensis Walcott............... hace pet ae Fic. 5. (X 1.5.) A nearly perfect cranidium. U.S. National Museum, Catalogue No. 63720. sa. (Natural size.) Interior of a large free cheek. U.S. National Museum, Catalogue No. 63730. 5b. (X2.) A pygidium somewhat crushed in the shale. U. S. National Museum, Catalogue No. 63731.
26
27
50
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SMITHSONIAN MISCELLANEOUS COLLECTIONS
ie dln ee
aN SS ss PUR RRR RY SARC EM ORME EET cs PLT AE OES FBR AE OEE bi
Pe ani une ro - LLL “ caine >: sae P ED HEM
etic OC ELEL ELLE OCH OE 2 RUE AEN NOIR Me
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i i
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aes
uy
ie
, AND TRILOBITES
, ANNELIDS
PTEROPODS
"el a , »
We ieee re oe
NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA
Bathyuriscus ressensis Walcott—Continued. PAGE
5c. (X2.) Asmall, fairly well-preserved pygidium. U.S. National Museum, Catalogue No. 63732.
sd. (Natural size.) A crushed dorsal shield, illustrating the general characters of the species. U. S. National Museum, Cata- logue No. 63733.
The specimens represented by figs. 5, 5a-d are from (Locality 631i) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake, British Columbia.
aryNItSeWS Cl: FOSSeNStS WAlGOtBiacavtagcenshe cece nscseav vet aees es cees - Fic. 6. (Natural size.) A large, partially exfoliated cranidium. U. S. National Museum, Catalogue No. 63734. 6’. Side outline of fig. 6. 6a. (X 3.) Pygidium associated with the cranidium represented by fig. 6. U. S. National Museum, Catalogue No. 63735. 6a’. Side outline of fig. 6a.
The specimens represented by figs. 6, 6a are from thin limestone layers interbedded in the Ross Lake shale (Locality 63m’), Middle Cambrian: Ptarmigan formation; Mount Bosworth, British Columbia.
49
on OV
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 07
DESCRIPTION OF PEATE 6
Ptychoparia~charaz, Walcott. .. 0 .niss oscrnes ieee abe sce eee 31 Fic. 1. (X2.) A cranidium, and the type specimen of the species. U.S. National Museum, Catalogue No. 63736.
From locality 4v, Middle Cambrian: Gordon shale; Gordon Creek, Montana.
Piycohoparta #2 ctlles Walcott... sccee te sh.s <6 hee eee Bn fy 32 Fic. 2. (X 5.) A small cranidium and the type specimen of the species. U. S. National Museum, Catalogue No. 63737.
From limestone of locality 63d, Middle Cambrian: Ptarmigan formation; Ptarmigan Mountain, Alberta.
Piychopatia’ candace Walcott. 1.0)... .0c0stseine Uae sae <b eee 28 Fic. 3. (X2.) A flattened dorsal shield with its pygidium broken and pressed down and free cheeks detached. They are out- lined from another cephalon which has one free cheek on which there appears to be the base of a postero-lateral spine. U.S. National Museum, Catalogue No. 63738. 3a. (X6.) Specimen of a dorsal shield with ten thoracic segments. U. S. National Museum, Catalogue No. 63739.
From locality 4v, Middle Cambrian: Gordon shale; Gordon Creek, Powell County, Montana.
Piychoparta: pylas Waleott. ox.0...0h..c05 00s ena siete ee eee 33 Fic. 4. (X6.) <A small dorsal shield. The palpebral lobes and some
details restored from other specimens. U. S. National Museum, Catalogue No. 63740.
4a. (X4.) A badly crushed dorsal shield well illustrating thoracic segments and parts of cranidium. U.S. National Museum, Catalogue No. 63741.
4b. (X2.) A small cranidium flattened in the shale. U. S. National Museum, Catalogue No. 63742.
4c. (X2.) The largest cranidium observed, illustrating the rapid increase in size of the frontal limb with increase in size of cranidium. U.S. National Museum, Catalogue No. 63743.
From locality 4q, Middle Cambrian: Gordon shale; on ridge between Gordon and Youngs Creeks, Powell County, Montana.
Crepicephalus chares Walcctt. o./.ccccus once ose Sess eee ee eee 35 Fic. 5. (X 3.) Broken cranidium showing surface characters. U. S.
National Museum, Catalogue No. 63744.
5a. (X 3.) Free cheek associated with fig. 5. U. S. National Museum, Catalogue No. 63745.
5b, 5c. (X3.) Pygidia associated with specimen represented by fig. 5. U.S. National Museum, Catalogue Nos. 63746 and 63747.
From locality 63d, Middle Cambrian: Limestone of Ptarmigan formation; Ptarmigan Peak, Alberta.
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NO. 2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA
ERNE See CPUL UPI VN IE GIUE 2 ceca crema nieiacio.s s'-)<.dclannie sc Slaleciics's sadain eee dees Fic. 6. (Natural size.) A nearly perfect dorsal shield, the type speci- men. U.S. National Museum, Catalogue No. 61729. After
Walcott, Smithsonian Misc. Coll., Vol. 64, pl. 36, fig. 6.
From locality 35c, Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth, British Columbia.
IMCOLEIUS A GONSLOMS EINVAL COLE: a. era xet era reaete ein eolioke SEES Iie oe 'ovevels'ova a's Fics. 7, 7a. (Natural size.) Top and side views of the type specimen of pygidium. U.S. National Museum, Catalogue No. 63748.
From locality 63b, Middle Cambrian: Limestone of Ptarmigan formation; Ptarmigan Peak.
Picnopsrs chwumericanus Walcott: . 2.21 acbtiite deste edd esse eeee cess Fics. 8, 8a, 8b. (X 1.5.) Broken cranidia that illustrate the form and details of the cranidium. U. S. National Museum, Cata-
logue Nos. 63749, 63750, 63751.
From locality 63j, Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake.
MrmCCNONIES. CAUFIIG NVALCOEE. . sc a coe Poe eee e Os ban date ede Sclecsoans Fic. 9. (X 4.) The type specimen of the cranidium, which is preserved in limestone and retains its original convexity. U. S. National Museum, Catalogue No. 63752. oa. (X4.) Pygidium associated with fig. 9. U. S. National Museum, Catalogue No. 63753.
From locality 610, Middle Cambrian: Limestone of Chetang formation; Robson Peak district, Alberta.
muLaminotacs cnopus WalcOlts...camisaatae Uitte <class cicdlv «eo islet odes ave Fic. 10. (X 3.) <A broken dorsal shield illustrating thorax. U. S. National Museum, Catalogue No. 63754. toa. (X2.) A cranidium associated with fig. 10. U. S. National Museum, Catalogue No. 63755.
From locality 4v, Middle Cambrian: Gordon shale; Gordon Creek, Montana.
ios) NI
40
43
58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67 DESCRIPTION OF PLATE 7
: PAGE
Alberiella. levis. Waleotti2.d ce cacesate esc as atone teeelaret hea Eee 39
Fic. 1. (X3.) The type specimen of cranidium. U. S. National Museum, Catalogue No. 63757. 1a. (X4.) . Pygidium associated with fig. 1. U. S. National Museum, Catalogue No. 63758.
From locality 61w, Middle Cambrian: Chetang formation lime- stone; Terrace Creek, Robson district, Alberta.
Albertella boswortht Walcott... +2 «sansa cecal. -aee eee eee 38 Fic. 2. (X 4.) <A cranidium preserving its natural convexity. U. S. National Museum, Catalogue No. 637509. 2a. (X3.) Asmall associated free cheek. U.S. National Museum, Catalogue No. 63760. 2b. (X4.) An associated pygidium preserving its convexity and narrow form. U.S. National Museum, Catalogue No. 63761.
From locality 6141p, Middle Cambrian: Chetang formation lime- stone; Coleman Creek, Robson district, Alberta.
3, 3a. (X1.5.) Almost entire dorsal shields somewhat flattened in the shale. U. S. National Museum, Catalogue Nos. 63762 and 63763.
The specimens represented are from (Locality 63)) Middle Cam- brian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake, British Columbia.
ab, 3c. (X 2.) Cranidium and pygidium for comparison with those of Albertella helena. U.S. National Museum, Catalogue Nos. 53413 and 53415. The figs. 3b, 3c are after Walcott, Smithsonian Misc. Coll., Vol. 53, 1908, pl. 1, figs. 4 and 6.
The specimens represented by figs. 3b and 3c are from (Locality 35c) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth, British Columbia. ,
ad. (xX 12.) Matrix of a minute cranidium impressed on the sur- face of a valve of Wimanella simplex. U. S. National Museum, Catalogue No. 63764.
From locality 63i, associated with figs. 3, 3a.
Albertelia: helena. WaleGtt.. 6.0 <.s\.% since el'd canna Sheen eee 30 Fic. 4. (Natural size.) A nearly entire dorsal shield, the type speci- men. U.S. National Museum, Catalogue No. 53410. The fig. 4 is after Walcott, Smithsonian Misc. Coll., Vol. 53, 1908, pl. 2, fig. I.
The specimen represented by fig. 4 is from (Locality 54) Middle Cambrian: Gordon shale; Scapegoat Mountain, Powell County, Montana.
7
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NO.2 ALBERTELLA FAUNA IN BRITISH COLUMBIA AND MONTANA 59
Albertella helena \Walcott—Continued. PAGE
5. (X2.) A dorsal shield with a more perfect cephalon than that . on fig. 5a. A matrix of a fine pygidium occurs just below on the same fragment of rock. U. S. National Museum, Catalogue No. 63765. 5a. (X3.) A nearly entire dorsal shield. U.S. National Museum, Catalogue No. 63766.
The specimens represented by figs. 5, 5a¢ are from the siliceous shales of (Locality 63j) Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; above Ross Lake, British Columbia.
Peer OMseNie “CMMOI NV AICOLE. sitttee nee case < Ce edactaddcesdasctvceces
Fic. 6. (X 3.) Cranidium preserved in limestone. U. S. National Museum, Catalogue No. 63767.
6a. (X 3.) Fragment of an associated pygidium. U. S. National Museum, Catalogue No. 63768.
From locality 63b, Middle Cambrian: Ptarmigan formation; Ptarmigan Peak, Alberta.
PEP ICHENNOTIGG WV AlCOtL<:cccicn carat dein wia visi: oan vvrelessereesacecsvedes Fic. 7. (X2.) A nearly entire dorsal shield somewhat crushed in the shale. The type specimen. U. S. National Museum, Cata- logue No. 61728. After Walcott, Smithsonian Misc. Coll.,
Vol. 64, pl. 36, fig. 5.
The specimen represented is from locality 35c, Middle Cambrian: Ptarmigan formation (Ross Lake shale) ; Mount Bosworth, British Columbia.
41
37
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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOLUME 67, NUMBER 3
CAMBRIAN GEOLOGY AND PALEONTOLOGY
IV No. 3.—FAUNA OF THE MOUNT WHYTE FORMATION
(WitTH PLatTEs 8 TO 13)
BY CHARLES D. WALCOTT
(PUBLICATION 2480)
CITY OF WASHINGTON PUBLISHED BY THE SMITHSONIAN INSTITUTION SEPTEMBER 26, 1917
BALTIMORE, MD., U. S. A.
ab ae
CAMBRIAN GEOLOGY AND PALEONTOLOGY
IV No. 3—FAUNA OF THE MOUNT WHYTE FORMATION
By CHARLES D. WALCOTT (With PLatEs 8 To 13)
CONTENTS PAGE
LN ROGHIELLIGIN. le pik Gao Che 6 DIR GOSIEOIESIn sc c's 0 CRG ICICI OIC er aon Re Rcaec 61
SEA rap IC sPOSIbIOM OL ter TAMA... semiarid sce «(elise we oes ses coe es 62
ROHS SMO MEL INCRE ALINI Arye cers ete ocays.<ie.a'o'cisuttitremere entree ereinicil sat sieiele 6 cio.ce efe.arcs 65
MesciapMonrop peneta and SPECIES... .. geese cust ween se wees ceeds cecesios 67 ILLUSTRATIONS
PLATES FACING PAGE
S, (Gogie ail Ae NAO CMON PLR OES. cols Doe oI SEER Tec SOIR 104
OMCOM NE TLOGMUSHANG cIVESONUCES «.. stmt eltteides sie be else © oldie tees elec 106
10. Corynexochus, Micromitra, Acrothele, Wimanella, and Obolus...... 108
11. Crepicephalus, Ptychoparia, Olenopsis, Dorypyge, and Shafferia...... 110
12. JPW DONO 3 Sout s Oe USS DOC AEE 6 0 ce ULM D Et GDC CCRC Cn mae 112
pa erauias Olenopsts, and) Piycho part. ooo .c.c0-0 ss once cece vec eens II4 INTRODUCTION
The name Mount Whyte formation was proposed in 1908* for a series of alternating bands of limestone and siliceous and calcareous shale found on the north slope of Mount Whyte with a total thickness of 386 feet (117.7 m.) ; on the south slope of Mount Bosworth 390 feet (118.9 m.) ; on the north slope of Mount Stephen above railroad tunnel 315 feet (96 m.), and on the southeast slope of Castle Moun- tain 248 feet (75.5 m.). The Mount Whyte and the Castle Mountain sections are on the eastern slope of the Continental Divide in Alberta, and the Mount Bosworth and Mount Stephen sections on the western slope in British Columbia, Canada.
The included fauna was referred to as of Lower Cambrian age and with it by inference a fauna of undetermined stratigraphic position,’ now known as the Albertella fauna of the Middle Cambrian.
* Smithsonian Misc. Coll., Vol. 53, 1908, p. 4. *For explanation of this reference see Smithsonian Misc. Coll., Vol. 67, pp. 9-12. SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL. 67, No. 3 61
62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
In 1914 Mr. L. D. Burling concluded after a thorough and admir- able study that on paleontological evidence the Albertella fauna was of Middle Cambrian age and that the specimens of Olenellus found in the Mount Whyte formation were examples of recurrence. On the basis of this conclusion Burling placed the Mount Whyte formation in the Middle Cambrian.
The discovery that the Albertella fauna occurs at an horizon 500 feet (152.4 m.) above the Mount Whyte formation materially affects this conclusion.”
Several stratigraphic sections that include the Mount Whyte formation have been published * and others will be after the conclu- sion of field work in 1917. The presentation and discussion of all sections studied will be given in a future paper on the stratigraphy of the formation.
STRATIGRAPHIC POSITION OF THE FAUNA
All of the stratigraphic sections in their upper portion have varying thicknesses of calcareo-arenaceous beds and bands of oolitic lime- stone. Inthe upper layers of limestone there is usually a well-marked fauna and at this horizon in three sections, at Mount Assiniboine, Ptarmigan Peak, and Mount Stephen, the fauna includes a represen- tation of the genus Crepicephalus, which attains its greatest develop- ment in the Middle and Upper Cambrian of America, where 16 species or more are known, the greater proportion being in the Upper Cambrian. The central portions of the sections include siliceous shales and finely arenaceous beds and relatively few fossils, while the beds toward the base are usually thin-bedded, more or less slightly calcareous sandstones, and contain a characteristic Lower Cambrian fauna with abundant fragments of ,.both Olenellus and Mesonacis, and without traces of forms usually considered characteristic of the Middle Cambrian fauna.
The fauna of the upper oolitic limestone in the Mount Stephen section at locality 58k, about 5 feet (1.5 m.) below the top of the Lower Cambrian in thin-bedded bluish-black and gray limestoné (3 feet) forming 1 of Mount Whyte formation, and the interbedded limestone at the top of 2, Mount Stephen section; just above the tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, British Columbia, includes:
2 Canadian Geol. Surv., Museum Bull., No. 2, Geol. Ser., No. 17, 1914, p. 36. 2 Smithsonian Misc. Coll., Vol. 67, 1917, pp. 12-18. ; ®Idem, Vol. 53, 1908, pp. 212-215.
Canadian Alpine Journal, Vol. 1, No. 2, 1908, pp. 240-242.
Smithsonian Misc. Coll., Vol. 67, 1917, pp. 15, 16. *Tdem, Vol. 64, 1916, pp. 203-204.
SNLOIS SS) FAUNA OF THE MOUNT WHYTE FORMATION 63
Acrotreta sagittalis taconica (Walcott) Helcionella elongata Walcott
Scenella varians Walcott Parmophorella sp.
Hyolithes billingsi Walcott Ptychoparia clusia Walcott Ptychoparia thia Walcott
Ptychoparia (pygidia)
Olenopsis agnesensis Walcott Crepicephalus celer Walcott Bathyuriscus (Poliella) primus Walcott
In the Ptarmigan Peak section the upper oolitic (acrece at locality 63a, east base of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line northeast of Lake Louise station on the Canadian Pacific Railway,
Alberta, includes: Nisusia (Jamesella) lowt Walcott
Wimanella catulus Walcott Hyolithes billingst Walcott Ptychoparia ? cercops Walcott Crepicephalus cecinna Walcott
At the Gog Lake section, locality 62w, No. 1 of section; oolitic limestone ; about 400 feet (123 m.) below summit of ridge above Gog Lake below Wonder Pass on Continental Divide, in British Columbia, 19 miles (30.4 km.) southwest of Banff, Alberta, the fauna has sev- eral species that occur at localities 58k, 63a above, and 61d (Foot- note, p. 64), and includes:
Archeocyathus (A.) pneu Walcott Kutorgina cf. cingulata Billings Micromitra (Paterina) labradorica (Billings) Nisusia (Jamesella) lowit Walcott Acrotreta sagittalis taconica (Walcott) Helcionella elongata Walcott
Scenella varians Walcott
Hyolithellus ? sp. undt.
Hyolithes billingsi Walcott Crepicephalus cecinna Walcott Ptychoparia cf. gogensis Walcott Ptychoparia skapta Walcott Ptychoparia thia Walcott
Olenopsis cleora Walcott
Dorypyge damia Walcott
The fauna listed from the three localities gives a general concep-
tion of the fauna associated with Crepicephalus in the upper portion.
of the formation. Its relations now appear to be more with the
1Tt must be recalled that all collections were obtained as incidental to stratigraphic work and are necessarily a very imperfect representation of the entire fauna at each locality and horizon; future thorough collections should yield much additional data.
64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
Mount Whyte than with the Ptarmigan fauna, but further field work may change this view.”
The fauna of the central and lower portions of the formation is given in the following table of genera and species:
Position in formation
Genera and species Lower | Middle | Upper
Archeocyathus (A.) atreus Walcott.............000. Aes ae S< G ORIG SrOMICa NW AlGOUE oem eens vs 3) RE Micromitra (Paterina) charon Walcott.............. Micromitra (Paterina) labradorica (Billings)........ Micromitra (Iphidella) pannula (White)............ Kutorgina cf. cingulata Billings .......4.......0.0605 Obolus Gamo Walcott. .t0-. eos ovsur. » « ookae tae eens Acrotreta sagittalis taconica (Walcott).............. Acrothelenciiitis: Walcott: »c.).6n ens - eee eee Nisusia (Jamesella) lowi Walcott............0.00000: ae Nisusta festinata (Billings). oe. ce. ss los ende keen Sx Wimanella icatulus Walcott. ©... ...../2oeieecss eee Flelcionelanclongata! Walcott. 00... ...ss bebe FS Hyotithes billings: Walcott 2...2. ..;.'. eek e lee x Hyoltthes cf. corinatus Matthew ..............--0..- Ei voleihesvso iat: o.2 soc eee ate ok ox s Hyolithellus cf. micans Billings...............++ecaees Fyolithellvs spa qindts acacstu ck. eonceee. neat Pelaciella) spatingts (a). aed tee nds ee eee eee Pelasiclla sincere cites cits.< = 36 oie sis od RR ee PORMOPROVENG SD sin. Ac ok tee akc ee ae wcenclla wartans Walcott). > cls c2 hs eee x Shaiierta cruswai Waleotts...0a..oo28. 5 oe aa eee Bradoria *(lareeispecies)).si. ute wasnt a eee FLV MenOCarts SMe TMs os & «sia. < G dc E Alutay (small species)... ce sc. «5 4 2h bee 0 eee at Apraulos charaps NValeott.«..\.2..0is2.. sae. ones ><
PR ON rn os
iy es aa ty REED AE tte eer
Se ae bt ete Gee
RAR A KK:
eX Eee
* Almost at the top of the oolitic limestone in the Mount Shaffer section at locality 61d, southwest slope of Mount Shaffer on Canyon side, on trail to Lake McArthur, 5.5 miles (8.8 km.) south of Hector Station, on Canadian Pacific Railroad, British Columbia, the fauna is Lower Cambrian in character and includes:
Micromitra (Paterina) labradorica Shafferia cisina Walcott
( Billings ) Corynexochus senectus (Billings ) Micromitra (Iphidella) pannula (White) Agraulos ? unca Walcott Acrotreta sagittalis taconica (Walcott) Zacanthoides Nisusia (Jamesella) lowi Walcott Ptychoparia lux Walcott Scenella varians Walcott Ptychoparia sp. undt.
Pelagiella sp. undt. (a) Mesonacis gilberti (Meek)
NOT 3 FAUNA OF THE MOUNT WHYTE FORMATION
Genera and species
65
Position in formation
Lower
Middle
Upper
Pieeuilosi Unco Walcott, v2. <2)... jee lewia tas ei! os o's Olenopsis agnesensis Walcott. ....scncane oes sse0ee: CEMON SES C1207 Walcott. asics. soo sta ages se sk a whens DITERGESESHELETO, NWAICOU 6 oc vec sss ORs ea aly wets Oilenopsis leuka Walcott .2...% 0... dadeesees oe een cee: Piychoparia adina Walcott. ........ canes cewiets tele n's e Pryehoparia coring Walcott. .:..... 2g net nastiness Ptychoparia cf. carina Walcott..... <a RRR Sie Piychoperia. 2 cercops. Walcott... cine. ssc se mse ss 5's iPivchoparia 7 cleadas Walcott. ....tecencn cs vce ncss ss iienoparia-cleow Walcott. 0.2... Seeawahiex oo 68 2 Ss miychoparsa cihisva: Walcotte. .(..: s+ seeeneccienenae oss cho pama cossts- Waleott...\...:./s tyamestsiee:s fois. e080 Piucheparia cuneds Walcott... << iguecaswis.« <cs0.0 08s Ptychoparia cf. cuneas Walcott............eeeeee eee | Pivenoparia gogensts Walcott. ..... dese ssc esc oases Picnopurma ina WalcGth. sss... ibamein sets oe owe She ts LUN GHOPOIVGN PICTOU NV AlCOLt ss os. cisateteyeleves aisles ete) stosee ivchoparias pia. Walcotts ii... . ibe se ices} see. ivehopariaeci. pra Walcott, . . ..sjasecs + dejo ee tee Dare IRIN GHOpaiG wSkOptan NV alCOtt..\.% .jebtaeats sic ares « Pijehoparia thia Walcott... .... Gass ne inna sees e's Pivchoparia sp. undt.............28 ete ie re Aa sce Grepicephalus cecinna Walcott. .i.c2ce. eevee ee ees Grepisepnatisnceler NNialGott.: : «5 aectetimiceiciee elci=t= ose 0 Morvryce amma. Walcott 260s «sige pace see ee eos Corynexochus senectus (Billings) ............6..0005 Corynexochus (Bonnia) fieldensis Walcott........... iexonacts eulberis. (Meek) s. ccsie ees eees cies eee ss Olenelius canadensis. Walcott. . «semen. ae - 2528s ee Over aiagce sire tin dtie sacctrs « slcvs evs Skoterert Neel sare eee siete aie Bathyuriscus (Poliella) primus Walcott.............. IBAA UDA ISICU RS AS Dee vi chinettaoies cadirastb oreo ha dO GH OO CeAD Ore
oe.
x XX
eK aa oe
Dae
SE ROD
UB Dr Soa
x x x
ee or
RO:
DK Oa OR DON TN OR a ee
NOTES ON THE FAUNA
One of the striking features of the 28 genera and 60 species of the Mount Whyte fauna is the presence of several species common to it and to the Lower Cambrian fauna of Newfoundland and the Cham- plain Valley of Vermont. In order to make this clear I have illustrated on plate 10, Corynexochus (Bonnia) parvulus (Billings ) from the Atlantic Province (figs. 1, Ia-c) and beside it C. (B.)
66 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
fieldensis (Walcott) (figs. 2, 2a-c) from British Columbia ; and on plate 9, Corynexochus senectus (Billings) from the Atlantic Province (figs. 1, ta-d) and beside it specimens considered identical from British Columbia (figs. 2, 2a-c). Mesonacis vermontana (Hall) (fig. 3) from the Atlantic Province is the representative of Mesonacis gilbertt (Meek) (fig. 4) from British Columbia. All of these species have about the same range of individual variation both in the Atlantic Province and British Columbia.”
Other species common to the Atlantic Province Lower Cambrian fauna and the Mount Whyte fauna are Micromitra (Paterina) labradorica (Billings), Kutorgina cf. cingulata (Billings), Acrotreta sagittalis taconica (Walcott), and Nisusia festinata (Billings).
There are several species of Ptychoparia from Lower Cambrian formations elsewhere that are very closely related to species from the _ Mount Whyte formation. These are now illustrated on plates 11 and 12, for the Mount Whyte species, and on plates 14 and 15, for the species of other formations. Ptychoparia cuneas and P. cossus (pl. 11) may be compared with P. crates and P. crantos (pl: 15) from Bic Harbor on the Lower St. Lawrence River, P. skapta (pl. 12, fig. 9) and P. deldon (pl. 15, fig. 2), P. thia (pl. 12, fig. 6) and P. adamsi (pl. 14, fig. 8a). With larger collections the allied species from the two sides of the continent would undoubtedly be much in- creased in number.
The presence of such a strong connecting series of forms at such widely separated localities and so far north on the continent indicates. a northern origin of the later phases of the Lower Cambrian or Olenellus fauna.
The trilobites, other than the Mesonacidz, indicate the rapid approach of the large series of genera and species that mark the Middle Cambrian fauna of North America. The Conocoryphide is represented by forms that range throughout the Cambrian although their range of variation may be sufficient to justify applying specific names to the varieties from the Lower, Middle and Upper Cambrian. Ptychoparia pia (pl. 12, fig. 8) is an illustration, also P. ? cleadas (pl pro ios 2)
*Comparisons of the eastern and western forms of Corynexochus senectus may be found in observations on the species made by me in 1916. Smithsonian Misc. Coll., Vol. 64, 1016, pp. 321-322.
* Plates 14 and 15 will accompany a paper on certain Lower Cambrian genera and species of trilobites which wil] be issued as Number 4 of this volume on Cambrian Geology and Paleontology.
NOs 3 FAUNA OF THE MOUNT WHYTE FORMATION 67
The generic relations of the Mount Whyte fauna to the superjacent Ptarmigan formation Albertella fauna is close despite the 500 feet (152.4 m.) of barren strata between the two faunas. Of the 28 genera of the Mount Whyte fauna 13 are represented in the Alber- tella fauna, and of the genera not present in the Albertella fauna 3 occur above it in the Stephen formation. More complete col- lections will undoubtedly increase the number of genera common to the two and at the same time may increase the number that are restricted to the Mount Whyte fauna.
Acknowledgments—tThe drafts of the descriptions of species of Ptychoparia for this and other papers to follow were drawn up by Dr. Julia Gardner, who studied the material with great care.
The profiles used in illustration are by Miss Frances Wieser, and where it was necessary to have the photographs retouched in order to bring out characters not readily photographed the work has been done by her.
DESCRIPTION OF GENERA AND .SPECIES ARCHAOCYATHUS (ARCHAOCYATHELLUS) ATREUS, new species Plate 8, figs. 2, 2a
This species is represented by two examples that are illustrated by figures 2,2a. The specimen represented by figure 2 varies in diameter from 2.2 mm. to 1.4 mm., and has a total length of 14 mm. A cross section shows a thick outer wall (fig. 2’) but no structural detail, as the calcite forming it is in a crystalline condition except in one place of the section where there is a trace of what may have been two septa. On the exterior surface in addition to the swelling of the wall there are concentric growth lines and slight depressions; no cells have been observed.
The nearest related species as indicated by exterior form is A. (A.) dwighti Walcott’ from the Lower Cambrian of eastern New York. Both are small undulating forms, but unfortunately no further comparison can be made as we do not know the structure of the wall OA.) atreus.
Formation and locality—Lower Cambrian: (62w) Mount Whyte formation ; oolitic limestone, about 400 feet (123 m.) below summit of ridge above Gog Lake, below Wonder Pass on Continental Divide, in British Columbia, 19 miles (30.4 km.) southwest of Banff, Alberta, Canada.
*Tenth Ann. Rept. U. S. Geol. Survey, 1891, pl. 54, figs. 4, 4a.
68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
Family Eocystipa Bather Eocystid@ BATHER, 1900, Treatise on Zodlogy, Lankester, Pt. 3, p. 48. GOGIA, new genus
All that is known of Gogia is included in the description of the genotype, Gogia prolifica. The form of the calyx and the character of the plates distinguish it from Eocystites as represented by the single plate described by Billings or by the species E. ? ? longidac- tylus Walcott,’ which is the only described species sufficiently well pre- served to indicate what Eocystites may possibly include.
Genotype—Gogia prolifica Walcott.
Stratigraphic range-——As far as known Gogza is confined to a massive band of calcareo-arenaceous shales 250 feet (76 m.) below the oolitic limestone at the summit of the Mount Whyte formation of the Lower Cambrian.
Geographic distribution—As far as known, it is confined to the vicinity of Wonder Pass southwest of Banff, Alberta.
GOGIA PROLIFICA, new species Plate 8, figs. 1, 1a-b
Calyx—Form: As seen flattened on the shale the outline is that of a narrow isosceles triangle pointing downward. The stem is attached to the apex of the triangle as inverted. A calyx 27 mm. in length has a width across the top of 12mm. The largest specimen has a length of 30mm. The plates of the calyx are polygonal, varying in size and form. The outer surface of the plates appears to have been roughened and the inner surface to have had a groove running from the central depressed area out to each angle on the margin of the plate ; the casts of these grooves are shown by figure 1a. The exterior of the plates is known only from the casts in the shale as the plates have usually been removed by solution of the calcite forming them.
The arms (eight on one specimen) are long, very slender, and formed of numerous plates in a biserial arrangement and with a narrow ambulacral furrow on the inner side.
The stem is slender, tapering gradually and formed of numerous elongate and round, thick, tumid plates varying in size. The elongate plates form the upper part of the stem to where it joins the calyx, and the round plates the lower portion out to near the end where a group of minute round plates occur. The round plates appear to have been smooth, and the oval elongate plates tuberculated.
* Bull. U. S. Geol. Surv., No. 30, 1886, p. 94.
NOS FAUNA OF THE MOUNT WHYTE FORMATION 69
Observations —This genus and species differ from described forms by the shape of the calyx and plates. The elongate arms and stem resemble the arms and stem of Eocystites ? ? longidactylus Walcott,’ but they differ in details.
So far as known to me, this is the oldest cystidian of this type. It occurs at an horizon 1,000 feet (304.8 m.) or more below the zone of Eocystites ?? longidactylus.
Formation and locality—Lower Cambrian: (62x) Mount Whyte formation ; Silici-caleareous shale, on ridge above Gog Lake, below Wonder Pass, on Continental Divide, in British Columbia, 19 miles (30.4 km.) southwest of Banff, Alberta, Canada.
MICROMITRA (PATERINA) CHARON, new species Plate 10, figs. 3, 3a-b
Some specimens of this species were confused with M. (P.) wapta Walcott * when collected in the field. It differs from the latter in form and in having a finely reticulated surface. It is more closely related to M. (J.) pannula,’ but it differs in having a much more finely reticulated surface and in the more elongate outline of the valves when they are undistorted (see figs. 1, 1b)... The largest valve observed has a length of 8 mm.
This shell is abundant on Mount Odaray at the type locality.
Formation and locality —Lower Cambrian: (61c) Mount Whyte formation; dark siliceous shale, east slope of southeast ridge of Mount Odaray, 7.5 miles (12 km.) south of Hector, on the Canadian Pacific Railway, British Columbia, Canada.
OBOLUS DAMO, new species Plate 10, figs. 6, 6a
This little shell is related to Obolus smithi from the Lower Cam- brian Montevallo shales of Alabama, from which it differs in its more circular outline. It also differs in the same manner from another Lower Cambrian species, O. prindlei’ from the Olenellus- bearing limestone of eastern New York.
The shells occur in a fine-grained, hard shaly arenaceous rock in which very little of the original shell is preserved. The interior cast
*Bull. U. S. Geol. Survey, No. 30, 1886, p. 94, pl. 6, figs. 1, 1a-c. Pack: Journ. Geol., Chicago, Vol. 14, 1906, p. 3, pl. 1, figs. I, Ia.
* Monogr. U. S. Geol. Survey, No. 51, 1912, p. 357.
*Tdem, p. 361, pl. 4.
*Tdem, p. 416.
*Idem, p. 409, pl. 27, figs. 3, 3a-e.
7O SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
of a ventral valve shows a broad visceral area of the type of that in Obolus apollinis Eichwald.*
Formation and locality—Lower Cambrian»: (63g) Mount Whyte formation; greenish arenaceous shale, southwest slope of Mount Temple, about 600 feet (184.6 m.) above base of Pinnacle Pass, and 1500 feet (461.5 m.) above upper portion of Paradise Valley, and south of Lake Louise, Alberta, Canada.
ACROTHELE CLITUS, new species Plate 10, figs. 4, 4a-c
This species differs from Acrothele colleni of the Ross Lake shale of the Ptarmigan formation, with which I had identified it in my field notes of 1908,” in having a uniformly smaller size and in the presence in the dorsal valve of a very long and strong median ridge, in this respect resembling Acrothele bellula of the Middle Cambrian of Alabama.?
The largest specimens in the collection have a diameter of 4 mm. and are very much flattened in the fine siliceous shale. The outer surface is marked by concentric striz and lines of growth and a few fine radiating lines.
Formation and locality Lower Cambrian: Mount Whyte forma- tion; (35e) Lake Agnes shale, amphitheater between Popes Peak and Mount Whyte, southwest of Lake Agnes and 3 miles (4.8 km.) west-southwest of Lake Louise station, on the Canadian Pacific Railroad, in western Alberta; also (57e) Mount Stephen section ; just above the tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, British Columbia, Canada.
WIMANELLA CATULUS, new species Plate Io, figs. 5, 5a-c
This is a more elongate form than Wimanella simplex Walcott of the Ptarmigan formation when specimens preserved in a similar matrix are compared. This is best shown by examining figure 8,* which illustrates a specimen of W. simplex from the limestone of the Ptarmigan formation, and figures 5, 5b, plate io, illustrating W. catulus in this paper. Several of the specimens from the two lime- stones have the same outline, but in such instances the convexity of
1 Monogr. U. S. Geol. Survey, Vol. 51, 1912, pl. 7, figs. 1-6.
? Smithsonian Misc. Coll., Vol. 53, p. 214, 3 of section.
°U. S. Geol. Survey, Monogr. No. 51, 1912, pl. 58, figs. 5f, 5h. * Smithsonian Misc. Coll., Vol. 67, 1917, pl. 4.
NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 7x
the specimens is quite different. Thus figure 5, plate 10 (this paper) is a strongly convex ventral valve and yet in outline it is much like the dorsal’ valve represented by figure 8a, plate 4 (Vol. 67, No. 2, Smithsonian Misc. Coll.).
The two species are closely related although there is about 500 feet (152.4 m.) of limestone between their respective positions in the section.
Of the known species of Wimanella three occur in strata referred to the Lower Cambrian and four to the Middle Cambrian.
Formation and locality—Lower Cambrian: (63a) Mount Whyte formation ; oolitic limestone about 130 feet (40 m.) above arenaceous shaly beds; east base of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line northeast of Lake Louise station on the Canadian Pacific Railway, Alberta, Canada.
SHAFFERIA, new genus
The species on which this genus is based does not appear to fall under any described genus. It has a carapace that suggests that of Burgessia,’ but it has a thick, strong, and ornamented carapace, while that of Burgessia is smooth and very delicate. It may be that I mis- interpret the species and that it is one of the Discinocarina and the notch is anterior and not posterior in position. The thick test and deep notch certainly suggest its belonging with the Discinocarina.
All that is known of the genus is given under the description of the type species.
Genotype.—Shafferia cisina Walcott.
Stratigraphic range.—This is limited to a thin layer of limestone near the summit of the Mount Whyte formation.
Geographic distribution.—Southwest slope of Mount Shaffer on trail to Lake McArthur, British Columbia, Canada.
The generic name is derived from Shaffer, the name of the moun- tain from which Shafferia cisina was collected.
SHAFFERIA CISINA, new species Plate 11, figs. 8, 8a
Of this species only a single carapace is known. This is bent over along the median line and strongly notched posteriorly. The general form is shown by figure 8 and a side view by figure 8a. The test is
* By misprint named ventral valve. * Smithsonian Misc. Coll., Vol. 57, 1912, p. 177, pl. 27, figs. 1, 3.
72 SMITHSONIAN MISCELLANEOUS CCLLECTIONS VOL. 67
rather thick and marked by flat, irregular ridges that are subparallel to the outer margin and almost transverse across the central portion.
The carapace is 3 mm. in length along the medial line and about 5 mm. in width.
Formation and locality—lLower Cambrian: (61d) Mount Whyte formation ; oolitic limestone, southwest slope of Mount Shaffer on Canyon side, on trail to Lake McArthur, 5.5 miles (8.8 km.) south of Hector Station, on Canadian Pacific Railroad, British Columbia, Canada.
AGRAULOS CHAROPS, new species Plate 13, figs. 2, 2a
Species known from an imperfect cranidium.
Cephalon.—Cranidium small, evenly convex. Glabella a little more than two-thirds the length of the cranidium, rather strongly elevated along the medial line which is highest near the occipital ring and slopes very gradually from the ring to the anterior extremity ; dorsal furrows linear, distinct, gradually converging to the broadly rounded anterior extremity which is about three-fourths as wide as the base ; anterior furrow narrow and shallow ; glabellar furrows very obscure; occipital groove rather broad, a little broader and more shallow medially than laterally; occipital ring narrow laterally, slightly expanded medially. Fixed cheeks low, wide and gently convex, the distance from the palpebral lobe to the dorsal furrow almost as great as the width of the glabella; postero-lateral lobe imperfectly preserved; posterior groove narrow and quite deep at the axial termination opposite the occipital ring, neither so narrow nor so deep away from the axis, and cutting off an increasingly wider posterior margin. Palpebral lobe small and inconspicuous, medial in position with respect to the glabella exclusive of the occipital ring. Palpebral ridge indicated only by the obtuse angulation of the cheek. Frontal limb and border not clearly differentiated, the two together forming a gently inclined frontal margin of approximately the same width as the fixed cheek, exclusive of the postero-lateral lobe. Facial sutures imperfectly preserved, the anterior section of the suture merging smoothly into the anterior extremity.
Surface—Exterior surface minutely shagreened.
Dimensions.—Length of cranidium, 4.3 mm.; length of glabella, 3.0 mm.; width of glabella in front, 1.5 mm.; width of glabella at base, 2.1 mm.
Type locality —(35£) Mount Stephen.
NOSa3 FAUNA OF THE MOUNT WHYTE FORMATION WS)
Observations —This species is unlike 4. (7) unca (fig. 1, pl. 13) and A. stator (Smithsonian Misc. Coll., Vol. 67, 1917, pl. 6, fig. 6) or any other species from the Lower Cambrian terrane.
Formation and locality—Lower Cambrian: (35f) Mount Whyte formation; about 300 feet (95 m.) below the top of the Lower Cambrian in bluish-black and gray limestone (18 feet=5.5 m.), forming 6 of Mount Whyte formation; just above the tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, British Columbia, Canada.
AGRAULOS (?) UNCA, new species Plate 13, figs. I, Ia
Species known from cranidia.
Cephalon.—Cranidium very simple in outline, broadly and evenly | rounded in front with two deltoid flanges at the base. Glabella three-quarters or more as long as the cranidium, subcylindrical, arcuate anteriorly; dorsal furrows linear, very faintly impressed, roughly parallel; glabellar furrows obsolete; occipital groove rela- tively broad but very shallow, uniform in depth between the dorsal furrows; occipital ring moderately broad, expanded medially, not nodose. Fixed cheeks and frontal limb and border not differentiated, together forming a rather broad and evenly declining brim around the glabella. Fixed cheeks rather narrow, the distance from the palpebral lobe to the dorsal furrow a little more than half the width of the medial portion of the glabella; postero-lateral lobe short and wide, obtusely cuneate at the distal extremity. Palpebral lobe very inconspicuous, defined merely by the outward arching in the facial sutures, very short and slightly anterior with respect to the glabella. Palpebral ridge faintly developed and not observable on most speci- mens. Frontal limb and border about one-third the length of the glabella, gently and evenly sloping, somewhat thickened toward the periphery. Facial sutures obtusely V-shaped, aS anterior section feebly arcuate. nes cheeks not preserved.
Bes on of cranidium, 2.5 mm.; width of cranidium at base, 3.0 mm.; length of glabella, 1.5 mm.; width of glabella in front, 1.9 mm. ; width of glabella at base, 2.0 mm.
Type locality—(61d) Mount Shaffer, British Columbia.
Observations —A graulos ? unca is exceedingly abundant at the type locality, but has been rarely observed elsewhere. The first comparison suggested is with Ptychoparia thia. It is a smoothed
74 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
out, rounded form, differing in the practical absence of glabellar furrows and palpebral ridges and in slight variations of the frontal! limb and border. The two species are associated at locality 35f. The generic reference is doubtful, but with only the cranidia for study nothing better seems possible.
Formation and locality —Lower Cambrian: Mount Whyte forma- tion; (61d) southwest slope of Mount Shaffer on Canyon side, on trail to Lake McArthur, 5.5 miles (8.8 km.) south of Hector Station, on Canadian Pacific Railroad; and (35f) Mount Stephen section ; about 300 feet (93.8 m.) below the top of the Lower Cambrian in bluish-black and gray limestone, just dbove the tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, both in British Columbia, Canada.
CLENOPSIS CLEORA, new species Plate 13, figs. 3, 3a
Species known from imperfect cranidia.
Cranidium.—Cranidium elongate. Glabella only about three-fifths as long as the cranidium, rather strong, elevated along a low but sub-acute ridge which becomes obsolete at some little distance behind the anterior extremity; dorsal furrows quite broad and not very deeply impressed, gradually converging so that the width at the truncate anterior extremity is only about two-thirds of that at the base ; glabellar furrows broad and shallow, obsolete upon the crest of the glabella, the posterior and medial pairs oblique, the anterior pair reduced to a couple of obscure lateral pits ; occipital furrow broad and shallow, deepening a little toward the dorsal furrows ; occipital ring low, flattened, moderately wide and carrying a small medial node. Fixed cheeks low and broad, the distance from the palpebral lobe to the dorsal furrow more than half the width of the medial portion of the glabella; postero-lateral lobe imperfectly preserved, narrow and probably petaloid at its extremity ; posterior furrow very shallow, in line with the occipital ring. Palpebral lobe moderately elevated, about one-third as long as the glabella, asymmetrically arcuate, sub- medial in position with respect to the glabella. Palpebral ridge nar- row, cordate, cutting somewhat obliquely across the fixed cheeks and intercepting the dorsal furrows at the origin of the anterior glabellar furrows. Frontal limb and border not sharply differentiated, the profile in front of the glabella gently concave. Frontal limb narrow, evenly declining medially, slightly convex laterally, cut off from the border by a shallow, ill-defined groove. Frontal border very wide,
NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 75
expanded medially, and broadly concave. Outline of facial sutures and fixed cheeks not well preserved ; anterior portion of facial suture apparently quite strongly arched.
Surface —Exterior surface shagreened with an exceedingly fine and close granulation.
Dimensions.—Length of cranidium, 16.0 mm.; length of glabella, 9.4 mm.; width of glabella in front, 4.6 mm.; width of glabella at base, 7.6 mm.
Type locality —(62w) Above Gog Lake, Wonder Pass. .
Observations.—There is a single pleural lobe of a thoracic segment associated with the cranidia which may perhaps be referable to this species. The segment is slender, not very deeply furrowed, and bent backward at an obtuse angle about halfway between the prox- imal and distal extremities.
The cranidium of this species recalls that of Olenopsis zoppi by its broad frontal border, narrow frontal limb, elongate glabella and strong palpebral ridge. It is quite distinct from any associated form or forms from the same geological formation. It differs from O. ? agnesensis* in shorter frontal limb and broad frontal border (see figs. 5, 5a, pl. 13).
Formation and locality —Lower Cambrian: Mount Whyte forma- tion ; (62w) oolitic limestone, about 400 feet (123 m.) below summit of ridge above Gog Lake, below Wonder Pass on Continental Divide, in British Columbia, 19 miles (30.4 km.) southwest of Banff ; (57S) about 160 feet (49 m.) below the Middle Cambrian, in gray oolitic limestone, on Mount Bosworth, north of the Canadian Pacific Railway between Hector and Stephen; and (63i) thin layer of sand- stone ; between two eastern gullies on southern slope of Mount Bos- worth, at about 6000-foot contour ; I mile (1.6 km.) west-northwest of Stephen on the Canadian Pacific Railway, British Columbia.
OLENOPSIS CRITO, new species Plate 11, figs. 6, 6a-b
Species known from detached portions of the cephalon.
Cephalon.—Cranidium large, and moderately convex. Glabella three-fifths as long as the cranidium, slender, subconical in outline, elevated along a rather prominent medial ridge which persists almost to the anterior extremity ; dorsal furrows shallow but distinct, rounding sharply into the more shallow anterior furrow; anterior
*Smithsonian Misc. Coll., Vol. 57, 1912, p. 242, pl. 36, fig. 2.
2
76 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
extremity broadly rounded and half as wide as the base; posterior and medial pairs of glabellar furrows broad, deeply impressed, sub- equal and parallel to one another, extending obliquely backward and disappearing abruptly a little more than halfway up the lateral slope ; third pair linear, transverse, shorter and much more shallow than those behind it ; and an anterior pair indicated by slight indentations close to the dorsal furrow; occipital groove very shallow medially, similar in character laterally to the posterior glabellar furrows; occipital ring slightly expanded medially and apparently bearing near the posterior margin a very inconspicuous medial node. Fixed cheeks low, flattened, and very wide, the distance from the palpebral lobe to the dorsal furrow almost as great as the width of the medial portion of the glabella; postero-lateral lobe slender and elongate, probably acutely angulated at its distal extremity. Palpebral lobe imperfectly preserved, crescentic, approximately one-third the length of the glabella, the posterior end of the lobe on a line with the base of the posterior glabellar furrows. Palpebral ridge obscure, narrow, cordate, arching obliquely across the cheek and intercepting the dorsal furrows directly in front of the third pair of glabellar furrows. Frontal limb wide, very gently declining in front of the glabella, but -rather steeply in front of the palpebral ridge. Frontal border also wide and gently concave, delimited from the limb by a low cord-like ridge. Facial sutures imperfectly preserved, posterior section ex- tended outward at from 10° or 15° off the transverse line ; anterior section also oblique and gently convex. Associated free cheek rather broad; inner portion of about the same width as the border, arching gently away from the palpebral lobe; border very wide, not conspicuously differentiated, produced posteriorly into moderately long, acutely tapering genal spines.
Surface.—Character of exterior surface not preserved.
Dimensions.—Length of a large cranidium, 25.0 mm.; length of glabella, 15.0 mm.; width of glabella in front, 6.6 mm.; width of elabella at base, 13.0 mm.
Type locality —(6o0e) Ptarmigan Pass.
Observations.—This is the largest species of the genus Olenopsis from the Mount Whyte formation. It compares in size with O. americanus of the Gordon shale,’ but it differs from that species in the character of the frontal limb and border and elongate postero-lateral limb of the cranidium. It occurs about 700 feet (213 m.) lower in
1See Smithsonian Misc. Coll., Vol. 67, 1917, p. 37, pl. 6, figs. 8, 8a-b.
I GiGY 8 FAUNA OF THE MOUNT WHYTE FORMATION Ti
the section than O. americanus. O. crito is unlike either O. ? agnesensis, O. cleora, or O. leuka, of the Mount Whye formation.
Formation and locality —Lower Cambrian: (60e) Mount Whyte formation ; about 75 feet (22.8 m.) from the base of the formation ; Ptarmigan Lake Pass at head of Corral Creek, 6 miles (9.6 km.) northeast of Laggan, Alberta, Canada.
OLENOPSIS LEUKA, new species Plate 13, fig. 4
Species known from imperfect cranidia. Cranidium.—Glabella approximately two-thirds the length of the -cranidium, trapezoidal in outline, broadly convex ; anterior extremity broadly rounded and almost three-fourths the width of the base; dorsal furrows linear, deeply impressed, evenly converging ; glabellar furrows almost obsolete, owing probably to the absence of the outer test; traces of the posterior and medial pairs preserved in some individuals in the form of lateral pits, just within the dorsal furrows, the posterior pair somewhat elongated oblique to the axis; occipital groove rather narrow, partially dissecting the crest of the glabella and deepening toward the dorsal furrows; occipital ring of an elevation similar to that of the glabella, expanded medially; the median node if originally present has been destroyed. Fixed cheeks plump and wide, the distance from the palpebral lobe to the dorsal furrow approximately equal to the width of the medial portion of the glabella ; postero-lateral lobe imperfectly preserved, rather nar- row, moderately extended, obtusely tapering at the distal extremity ; posterior groove quite deep, broadening away from the axis and cutting off an increasingly wider posterior margin. Palpebral lobe also imperfectly preserved but apparently low, short and submedial with respect to the glabella. Palpebral ridge obscure. Frontal limb narrow, flattened medially, merging into the fixed cheeks laterally. Frontal border defined by a shallow groove, thickened, upturned, and slightly expanded medially so that the width in front of the glabella is greater than that of the limb. Free cheeks unknown but probably narrow and produced posteriorly into slender spines. Other characters not preserved.
Surface—Exterior surface unknown owing to the character of the matrix, a fine and very tough quartzitic sandstone.
Dimensions.—Length of cranidium, 7.5 mm.; length of glabella, 4.8 mm.; width of glabella in front, 2.3 mm.; width of glabella at base, 3.0 mm.
Type locality —(58g) Mount Bosworth.
73 SMITHSONIAN MISCEILLANEOUS COLLECTIONS VoL. 67
Observations.—The groove which separates the frontal limb from the border is obsolete medially, and the rim often has the appearance of being slightly produced posteriorly directly opposite the glabella. This character recalls P. lux, a smaller species with a more slender glabella, quite sharply rounded at the anterior extremity. The obscurity of the glabellar furrows is probably due in large measure to the character of the matrix, a rather firm quartzitic sandstone.
Formation and locality —Lower Cambrian: Mount Whyte forma- tion; (58g) about 200 feet (60 m.) below the top of the Olenellus zone in sandstones and shales, a few yards north of the Canadian Pacific Railroad track, midway between Stephen and Hector, on south slope of Mount Bosworth, British Columbia, Canada.
PTYCHOPARIA ADINA, new species Plate 12, figs. 3, 3a-b
Species known from the cranidia and associated free cheeks, pygidia and disjointed thoracic segments.
Cephalon.—Cranidium small and approximately twice as broad at the base as it is long. Glabella quite strongly elevated along an obtuse median ridge, about three-quarters of the length of the cranidium, elongate-trapezoidal in outline, the squarely truncate anterior extremity only a little more than two-thirds as wide as the base ; dorsal furrows linear, deeply impressed, evenly converging ; anterior furrow not quite so deep as the lateral furrows; glabellar furrows very obscure, in most individuals practically obsolete, indi- cated in others by very feeble depressions toward the dorsal furrows, the posterior pair oblique, the medial and anterior pairs at right angles to the axis of the shield; occipital furrow moderately broad and quite deep, especially toward the dorsal furrows; occipital ring rather broad, expanded medially and bearing, midway between the margins, a small node. Fixed cheeks rising obliquely from the dorsal furrows, moderately wide, the distance from the palpebral lobe to the dorsal furrow approximately half the width of the medial portion of the glabella; postero-lateral lobe rather wide, extended laterally and obtusely angulated at the distal extremity; posterior furrow deeply channeled, cutting off an increasingly wider posterior margin away from the axis. Palpebral lobe not greatly elevated, rather short, contained a little less than three times in the length of the glabella, quite strongly crescentic, slightly anterior in position. Palpebral ridge obscure, somewhat oblique to the axis, intercepting the dorsal furrows a little behind the anterior extremity. Frontal
NO 3 FAUNA OF THE MOUNT WHYTE FORMATION 79
limb of moderate width, moderately convex. Frontal border cut off from the limb by a shallow linear groove, not so wide as the limb, flattened but not thickened. Facial sutures imperfectly preserved, apparently a rather symmetric W, the posterior section oblique, the base convex, the anterior section broadly arcuate. The associated free cheeks moderately wide, rather plump, the peripheral margin a flattened band cut off from the rest of the cheek by an ill-defined groove; outer margin abruptly constricted posteriorly and produced into very slender acutely tapering genal spines.
Thorax.—Thoracic segments rather narrow, deeply sulcated medially, slender and acutely falcate at their distal extremities.
Pygidium.—Associated pygidium comparable in dimensions to the cephalon, rudely lenticular in outline. Axial lobe broad, strongly -convex, obtusely truncate at the posterior extremity ; axial annula- tions distinct anteriorly, obscure posteriorly, indicating 4 component segments and a terminal section. Pleural lobes of approximately the same width anteriorly as the axial, wedging out posteriorly ; pleural furrows rudely parallel to the anterior margin, increasingly shallow toward the posterior extremity. Peripheral rim narrow, smooth, defined only by the abrupt disappearance of the pleural grooving. Posterior extremity very broadly rounded or obtusely truncate.
Surface -—Exterior surface microscopically granulated.
Dimensions.—The largest cranidium in the collection has a length of 8 mm., but the average size is 4 mm. or less in length.
Type locality —(57q) Mount Bosworth, British Columbia.
Observations.—The limestone at the type locality is densely packed
with the cranidia, free cheeks, and less frequently the thoracic seg- ments and pygidia of this species. _ P. lux, of the Mount Whyte formation, has a more slender glabella, which tapers to a rounded anterior extremity instead of being squarely truncate as in P. adina; furthermore, the fixed cheeks are wider in Jux than in adina, the palpebral lobe is not placed so far forward, the frontal limb is narrower medially, and the frontal border is expanded and tends to be somewhat produced posteriorly directly opposite the anterior extremity of the glabella. P. adina is quite distinct from P. thia and Agraulos ? unca.
Formation and locality—lLower Cambrian: (57q) Mount Whyte formation ? (Mount Bosworth section) ; drift block supposed to be from about 200 feet (61.2 m.) below the top of the Lower Cambrian in bluish-gray limestone (60 feet) forming 16c in Mount Whyte
80 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
formation, slopes of Mount Bosworth, a little north of the Canadian Pacific Railway track, between Stephen and Hector, British Colum- bia, Canada. PTYCHOPARIA CARINA, new species Plate 13, figs. 6, 6a
Species known from a single imperfect cranidium.
Cranidium.—Cranidium apparently short and broad. Glabella not far from three-quarters the length of the cranidium, moderately broad and moderately elevated along an obtuse medial ridge which becomes obsolete at some little distance behind the anterior extremity ; dorsal furrows rather shallow; anterior extremity of the glabella more strongly rounded than the frontal border and only about two- thirds as wide as the base; glabellar furrows conspicuously deep, the posterior pair much more produced than the medial and more strongly oblique; medial pair short, but deeply gouged toward the dorsal furrows; anterior pair reduced to a couple of obscure lateral pits; character of occipital furrow and ring not preserved. Fixed cheeks low and broad, the distance from the palpebral lobe to the dorsal furrow more than half the width of the medial portion of the glabella; postero-lateral lobe imperfectly preserved but apparently slender and elongated ; posterior groove rather broad and moderately deep. Palpebral lobe not preserved but probably short, inconspicu- ous and placed far back, in line with either the posterior glabellar furrows or the posterior lobe of the glabella. Palpebral ridge narrow, cordate, arching obliquely across the fixed cheeks and intercepting the dorsal furrows at some little distance behind the anterior ex- tremity. Frontal limb flattened, very narrow medially. Frontal border a rather broad fillet, cut off from the limb by a sharply defined groove, and a little wider medially than the limb. Other characters not preserved.
Surface —Exterior surface shagreened with a fine and close granu- lation; a few coarser macroscopic granules scattered sparsely over the surface of the cranidium.
Dimensions —Length of cranidium, 13.2+ mm.; length of gla- bella, 9.5-+mm.; width of glabella in front, 4.5 mm.; width of gla- bella at base, 6.8mm.
Type locality—(35m) 3 miles (4.8 km.) southwest of head of Lake Louise, Alberta.
Observations —This species has such a thickly granulated and pustulose surface and such a strong frontal border that it is readily distinguished from other species of this horizon and fauna. The
NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 81
granulation recalls that of P. permulta, a species occurring in the Albertella shale about 700 feet (213.4 m.) higher in the section.
Formation and locality —Lower Cambrian: (35m) Mount Whyte formation ; 3 miles (4.8 km.) southwest of the head of Lake Louise, on east slope of Mount Whyte, Alberta, Canada.
PTYCHOPARIA (?) CERCOPS, new species Plate 12, figs. 1, 1a-d
Species known from imperfect cranidia, free cheeks, and pygidia.
Cephalon.—Cephalon not found entire. Cranidium large, feebly contoured. Glabella long relatively, almost four-fifths the length of the cranidium, slightly elevated along a narrow but rather distinct ridge which becomes obsolete at some little distance behind the anterior extremity; dorsal furrows shallow, gradually converging toward the broadly arcuate anterior extremity; glabellar furrows broad and exceedingly obscure, the posterior pair oblique, the medial pair transverse to the axis, the anterior pair probably very short, and parallel to the medial furrows, but in the majority of individuals entirely obsolete; occipital furrow very broad and very shallow especially upon the crest of the glabella; occipital ring low and flattened, expanded medially, bearing near the posterior margin a small but prominent node. Fixed cheeks low, narrow, the distance from the palpebral lobe to the dorsal furrow a little less than half the width of the medial portion of the glabella; postero-lateral lobe wide, cuneiform, obtusely angulated at the distal extremity, not quite twice as long as its greatest width; posterior groove broad and shal- low, narrowest and deepest toward the dorsal furrow, its proximal extremity in line with the occipital ring. Palpebral lobe very incon- spicuous, very short, only about one-fifth as long as the glabella, scarcely at all elevated, and placed far forward opposite the ante- rior glabellar furrows. Palpebral ridge not defined, obscurely suggested. Frontal limb and border slightly differentiated from one another, the profile between the anterior extremity of the glabella and the outer margin gently concave. Facial sutures rudely and asymmetrically V-shaped, the posterior arm oblique, the anterior arm broadly and quite strongly arched. Associated free cheeks low and broad, gently and smoothly convex, bordered by a wide and ill- defined band, and without traces of genal spines.
Thorax.—Associated thoracic segments of moderate width. Axial lobe not preserved. Pleural segments flexuous, posteriorly directed and acutely falcate at their distal extremities; pleural furrows
82 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
obsolete toward the axis, very deeply channeled medially, gradually wedging out distally; anterior margin a little narrower and more sharply elevated than the posterior.
Pygidium.—Associated pygidia twice as broad as long. Axial lobe broadly but not very strongly arched, subcylindrical, obtusely tapering posteriorly, rather sharply annulated even to the posterior extremity, including, apparently, 4 component segments. Pleural lobes differentiated from the axial merely by the contour, not cut off by incised furrows; annular ridges of the axial lobe persistent across the pleura, for the most part without change in direction or character, the posterior ridges, however, obsolete upon the pleura. Peripheral rim narrow, flattened, reduced to a mere thread pos- teriorly, widening gradually toward the thorax. Posterior extremity sharply rounded. .
Surface——Exterior surface shagreened but not distinctly gran- ulated.
Dimensions —Length of a cranidium, 20.4 mm. ; length of glabella, 16.1 mm.; width of base of glabella, 12.5 mm.; width of front of glabella, 6.3 mm.
Type locality — (63c) Ptarmigan Peak. /
Observations —The cranidium of P. cercops Walcott is relatively large and relatively long, and the relief upon the cranidium is con- spicuously low. It is quite abundant at the type locality, but is not found commonly elsewhere.
Formation and locality —Lower Cambrian: Mount Whyte forma- tion; (63c) 85 feet (26 m.) up in alternating oolitic limestone and thin-bedded compact sandstones forming 1 of section, and (63a) oolitic limestone about 130 feet (40 m.) above arenaceous shaly beds ; both from east base of Ptarmigan Peak, 5.5 miles (8.8 km.) in an air line northeast of Lake Louise station on the Canadian Pacific Railway, Alberta, Canada.
Small cranidia in a compact shaly sandstone matrix from the Mount Whyte horizon of Castle Mountain appear to be identical with cranidia of similar size of this species. Locality 58t, Lower Cambrian: Mount Whyte formation; sandy shale about 150 feet (45.7-m.) below the Middle Cambrian, just below the big cliff on the east shoulder of Castle Mountain, north of the Canadian Pacific Railway, Alberta.
Somewhat similar cranidia occur in the oolitic limestone of Ross Mountain, but they have a slightly more distinct glabellum and are
NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 83
not quite so much smoothed out. Locality 63k, Lower Cambrian: Mount Whyte formation; above and southeast of Ross Lake, 1 mile (1.6 km.) south of Stephen, Canadian Pacific Railway, on Con- tinental Divide, British Columbia, Canada.
PTYCHOPARIA (?) CLEADAS, new species Plate 12, fig. 2
Species known from cranidia.
Cephalon —Cranidium minute, angular in outline, narrow and truncate in front, relatively wide at the base. Glabella long, ap- proximately three-fourths the length of the cranidium, quite strongly elevated along the sharply rounded medial ridge, trapezoidal in out- line; dorsal furrows linear, incised, converging with a moderate degree of rapidity toward the squarely truncate anterior extremity ; glabellar furrows rather obscure, the posterior pair inclined to the median axis at an angle of about 45°, not persistent across the crest of the glabella, the medial pair a little shorter and less oblique, and the anterior pair much reduced and in some individuals entirely obsolete; occipital groove narrow and deep, uniform in character between the dorsal furrows; occipital ring flattened, constricted laterally, widely expanded medially and bearing near the posterior margin a small medial node. Fixed cheeks wide and evenly declining from the dorsal furrows; postero-lateral lobe very wide, deltoid in outline, probably obtusely angulated at its distal extremity ; posterior furrow narrow but deeply incised, cutting off an increasingly wider posterior margin away from the axis. Palpebral lobe imperfectly preserved but apparently very short, inconspicuous, and placed far forward opposite the medial glabellar furrows. Palpebral ridge very narrow but usually distinct, arching across the fixed cheeks and intercepting the dorsal furrows directly behind the anterior ex- tremity of the glabella. Frontal limb narrow, flattened. Frontal _border a little wider than the limb, thickened, cordate, and somewhat expanded medially. Facial sutures very imperfectly preserved, the posterior section very long relatively and probably oblique, the anterior arm short and probably arcuate. Other characters not preserved.
Surface —Exterior surface felt-like.
Dimensions.—Length of cranidium, 2.0 mm.; length of glabella, 1.5 mm. ; width of cranidium at base, 3.0+ mm. |
Type locality —(57s) Mount Bosworth.
84 SMITHSONIAN MISCELLANEOUS COLLECTIONS . VOL. 67
Observations —P. (?) cleadas Walcott may be readily separated from other species of the genus by its very small size and angular outline, its sharply defined trapezoidal glabella, its very small anterior eye placed far forward and the consequently very wide posterior lobe, its very narrow limb and almost equally narrow cordate border roughly parallel to the base of the cranidium.
These carbon-black cranidia, though so minute, show up quite well in the gray limestone of the type locality.
The specimens from the arenaceous shale at Ptarmigan Pass (Locality 60e) are in the form of casts and do not show the glabellar furrows, but this appears to result from the condition of preserva- tion. The glabella is also relatively shorter than that of the specimen illustrated but not shorter than some of those in the same hand specimen of limestone containing the type specimen.
Formation and locality —Lower Cambrian: Mount Whyte forma- tion; (578) about 160 feet (49 m.) below the Middle Cambrian, near the base of the gray oolitic limestone, on Mount Bosworth, north of the Canadian Pacific Railway between Hector and Stephen, on the Continental Divide between British Columbia and Alberta ; (58u) drift block supposed to have come from about 240 feet (73.8 m.) below the top of the Lower Cambrian in limestone inter- bedded in sandstone (31 feet) ; slopes of Mount Bosworth, a little north of the Canadian Pacific Railway track, between Stephen and Hector, British:Columbia; also (60e) about 75 feet (22.8 m.) from the base of the Mount Whyte formation; Ptarmigan Lake Pass at head of Corral Creek, 6 miles (9.6 km.) northeast of Laggan, Alberta, Canada.
PTYCHOPARIA CLEON, new species
Plate 12, fig. 10
Species known from an imperfect cranidium.
Cephalon—Cranidium small and moderately convex. Glabella low, elevated along an obscure median ridge which is moderately elevated posteriorly and increasingly lower anteriorly; dorsal fur- rows linear, rather shallow, converging so that the width of the truncate anterior extremity is about three-fifths of that at the base; elabellar furrows obscure, the posterior and medial pairs subparallel, disappearing about halfway up to the median line; anterior pair obsolete ; occipital groove rather shallow, deepening slightly toward the dorsal furrows; occipital ring imperfectly preserved. Fixed cheeks low, wide, the distance from the palpebral lobe to the dorsal furrow more than half the width of the medial portion of the
NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 85
glabella; postero-lateral lobe imperfectly preserved but probably strong and moderately extended; posterior groove very narrow toward the axis, terminating opposite the occipital ring, broader and more shallow away from the axis, and cutting off an increasingly wider posterior margin. Palpebral lobe narrow, crescentic, contained about three times in the length of the glabella, in line with the pos- terior glabellar furrows. Palpebral ridge oblique, defined only by the angulation of the cheek, not outlined by a raised cord or liration. Frontal limb rather narrow in front of the glabella and flattened, rather steeply declining in front of the palpebral ridge. Frontal border narrow, thickened, the medial portion posteriorly produced and acutely angulated. Facial sutures imperfectly preserved; an- terior section apparently very strongly convex.
Surface——Exterior surface microscopically shagreened. Vena- tion upon the frontal limb very fine.
Dimensions—Length of cranidium, 3.5 mm.; length of glabella, 2.5 mm.
Type locality.—(35f) Mount Stephen.
Observations —The cranidium of this species is much like that of Ptychoparia thia except that the frontal limb is longer in front of the glabella and there is a swelling or elongate tubercle on the frontal rim opposite the glabella. The species is known only by a single specimen of the cranidium from the limestone at the type locality (35f).
Formation and locality.—Lower Cambrian: (35f) Mount Whyte formation; about 300 feet (95 m.) below the top of the Lower Cambrian in bluish-black and gray limestone (18 feet=5.5 m.) form- ing 6 of Mount Whyte formation; just above the tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, British Columbia, Canada.
PTYCHOPARIA CLUSIA, new species Plate 11, figs. 3, 3a
Species known from imperfect cranidia.
Cephalon.—Glabella a little more than two-thirds as long as the cranidium, quite strongly elevated along a subacute medial ridge which disappears gradually toward the front; outline trapezoidal, the broadly rounded anterior extremity not more than half as broad as the base; dorsal furrows rather wide, deeply impressed, converg- ing quite rapidly anteriorly and rounding sharply into the more shallow, transverse anterior furrow; glabellar furrows also broad
86 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
and deep, though not persistent across the crest; posterior pair inclined to the axis of the shield at an angle of a little more than 45°, almost completely isolating the tumid posterior lobe; medial pair neither so broad nor so deep as the posterior and nearly at right | angles to the axis; anterior pair a little shorter than the medial, slightly inclined toward the front and placed nearer to the medial pair than to the anterior furrow; occipital groove broad and deep, completely dissecting the crest of the glabella, very slightly sinuous ; occipital ring rather narrow, expanded medially, obtusely angulated at the medial posterior margin, and bearing a rather prominent medial node. Fixed cheeks plump and quite wide, the distance from the palpebral lobe to the dorsal furrow a little more than half: the width of the medial- portion of the glabella; postero-lateral lobe narrow and probably extended laterally ; posterior furrow conspicu- ously broad and deep, its inner terminus in line with both the occipital furrow and ring; posterior margin narrow and sharply elevated. Palpebral lobe short, narrow, crescentic, set opposite the lobe between the posterior and medial furrows. Palpebral ridge rather prominent, cordate, arching across the fixed cheeks and intercepting the dorsal furrows directly in front of the anterior glabellar furrows. Frontal limb rather narrow, inflated laterally, gently declining medially. Frontal border wider medially than the limb, sharply upturned. Facial sutures imperfectly preserved.
Surface —Exterior surface very finely and closely granulated or roughened by an irregular pitting with broken, depressed ridges that give the effect of obscure granulation.
Dimensions —Length of cranidium, 7.5 mm.; length of glabella, 5.25 mm.; width of glabeila in front, 2.0 mm.; width of glabella at base, 4.2 mm.
Type locality—(58k) Mount Stephen.
Observations.—The glabella of this species recalls that of P. gogensis and less:‘so that of P. pia (pl. 12, figs. 4 and 8). ~The frontal border is quite unlike that of either of the two species.
Formation and locality—lLower Cambrian: (58k) Mount Whyte formation ; just above the tunnel, north shoulder of Mount Stephen, 3 miles (4.8 km.) east of Field, British Columbia, Canada.
PTYCHOPARIA COSSUS, new species Plate 11, figs. 5, 5a Species known from an imperfect cranidium. Cephalon—Cranidium small, moderately convex. Glabella a little more than ‘three-fourths as long as the cranidium, moderately
NO. 3 FAUNA OF THE MOUNT WHYTE FORMATION 87
elevated along an obtuse median ridge, relatively broad; dorsal fur- rows well rounded and quite deep, converging so that the rounded truncate anterior extremity is only a little more than two-thirds as wide as the base; anterior furrow shallow and not sharply defined ; elabellar furrows rather obscure and not persistent to the crest of the glabella, the posterior pair oblique, the medial pair more nearly horizontal, the anterior pair slightly inclined toward the anterior extremity ; occipital furrow sinuous, arched forward upon the crest, deepening toward the dorsal furrows; occipital ring not preserved. Fixed cheek low, flattened, the distance from the palpebral lobe to the dorsal furrow a little more than half the width of the glabella ; postero-lateral lobe imperfectly preserved, narrow and elongate ; pos- terior groove narrow but well rounded, in line with the occipital ring. Palpebral lobe very short, not very prominent, in line with the pos- terior glabellar furrows. Palpebral ridge low, cordate, cutting obliquely across from the palpebral lobe and intercepting the dorsal furrows at the origin of the anterior glabellar furrows. Frontal limb narrow and flattened in front of the glabella. Frontal border wide, slightly convex, somewhat thickened, the inner margin almost at right angles to the axis, the outer margin strongly arcuate. Facial sutures imperfectly preserved.
Surface —Exterior surface minutely shagreened.
Dimensions —Length of cranidium, 8.0 mm.; length of glabella, 5.5 mm.
Type locality—(61a) Yoho Canyon.
Observations—The glabella of this species recalls that of P. cuneas, but the frontal limb differs in being narrower and in having a gently convex surface.
Formation and locality Lower Cambrian: (61a) Mount Whyte formation ; gray oolitic siliceous limestone; Yoho Canyon, 1.5 miles (2.4 km.) above mouth of Yoho River and about 5.5 miles (8.8 km.) from Field on Canadian Pacific Railway, British Columbia, Canada.
PTYCHOPARIA CUNEAS, new species Plate 11, figs. 4, 4a
Species known from an imperfect cranidium.
Cephalon.—Glabella relatively short, only about two-thirds as long as the cranidium, moderately convex, trapezoidal in outline; dorsal furrows moderately deep, rounding rather sharply into the shallow ‘groove which outlines the truncated anterior extremity. Glabellar furrows imperfect; posterior pair rather broad, shallow and ex-
88 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67
tending obliquely inward to a low, strong medial ridge that continues nearly to the front of the glabella; the medial and anterior pairs transverse; occipital groove broad and. shallow upon the summit of the glabella, narrow and deep toward the dorsal furrows ; occipital ring moderately elevated and expanded medially, bearing a small but rather sharp medial node. Fixed cheeks slightly convex, the distance from the palpebral lobe to the dorsal furrow approximately half the width of the medial portion of the glabella ; postero-lateral lobe rather narrow, posterior groove narrow, deep, its axial terminus in line with the occipital ring. Palpebral lobe short, crescentic, not very prominent, placed rather far back opposite the posterior gla- bellar furrows. Palpebral ridge low and ill-defined, it arches ob- liquely across the fixed cheek and intercepts the dorsal furrow a little behind the anterior extremity. Frontal limb narrow, flattened in front and merging into the fixed cheeks laterally. Frontal border slightly elevated, flattened, and with a shallow, transverse median depression, slightly expanded both along the outer and the inner margin, wider than the frontal limb and cut off from it by a shallow sulcus. Facial sutures imperfectly preserved ; anterior section gently arcuate.
Surface—Exterior surface exhibiting a felt-like texture.
Dimensions —Length of cranidium, 8.0 mm.; length of glabella, 5.1 mm.; width of glabella in front, 2.7 mm.; width of glabella at base, 4.5 mm.
Type locality —(35£) Mount Stephen.
Observations.—The broad, short glabella and broad frontal border of this species serve to distinguish it from other species of Ptycho- paria from the Mount Whyte formation. The frontal border has a slight resemblance to that of P. gogensis (pl. 12, fig. 4). The short, broad glabella recalls