SMITHSONIAN MISCELLANEOUS COLLECTIONSVOLUME 57, NUMBER ii
CAMBRIANGEOLOGY AND PALEONTOLOGY
IINo. IL-NEW LOWER CAMBRIAN SLBEAUNA(With Plates 50 to 54)
BYCHARLES D. WALCOTT
(Publication 2185)
CITY OF WASHINGTONPUBLISHED BY THE SMITHSONIAN INSTITUTIONJULY 21, 1913
BALTIMORE, MD., U. S. A.
CAMBRIAN GEOLOGY AND PALEONTOLOGYIINo. II.—NEW LOWER CA^IBRIAN SUBFAUNABy CHARLES D. WALCOTT(With Plates 50 to 54)CONTENTS p:^GEIntroduction 309Description of species 310Mickisjitzia muralciisis, new species (pi. 50, rtgs. 10, 11; pi. 51, tigs.1-6; pi. 52, fig. I) 310Lillian!ella chapa, new species ( pi. 50, figs. 4-g) 311LbigitlcUa Iiitka. new species (pi. 50. figs. 1-3) 312Obolella uiida. new species ( pi. 52, figs, yj) 312Obolella cf. cliromatica Billings ( pi. 52, fig. 2) 313Holniia ? macer, new species (pi. 54, fig. i) 313JJ'aniicria occidens, new species (pi. 53, fig. 2) 314Callavia eucharis, new species (pi. 53, fig. i ) 315Callaz'ia perfect a, new species ( pi. 53, figs. 3-5) 315Olenellus tniciiiani. new species (pi. 54, figs. 2-10) 316ILLUSTRATIONSPL.\TES P.\(,E50. Liiigiilclla Iiitka, Lingulclla chapa, and Mickzi'itzia muralciisis 31851. Mickwitzia muralensis 32052. Mickwitzia muralensis, Obolella cf. cliromatica, and Obolella inida. .. . 2--^53. Callavia eucharis, Wanneria occidens. and Callaiia pcrfccta 32454. Hohnia ? macer and Olenelhis trucmani 326INTRODUCTIONDuring the season of 1912. while making- a reconnoissance of aportion of the Robson Peak District north of the Peak I found a blockof (lark siliceous sh.ale on the surface of Mural Glacier that containeda fine species of Olcnellus and numerous specimens of a species ofMickivitzia and Lingulclla. The source from which the block camewas found in a cliff two miles up the glacier at the foot of MummSmithsonian Miscellaneous Collections, Vol. 57, No. 11. 309
3IO SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/Peak, which is a high point (9,740 feet = 2,968 m.) directly north ofRobson Peak. The blocks of shale falling- from the cliff had beencarried out and down the ice of Mural Glacier. The glacier alsopasses over the cliff of shale for half a mile to the west. We reachedthe glacier by climbing up over the cliffs of Mural Brook, whichenters Smoky River about a mile (1.6 km.) below the mouth of Calu-met Creek. From the foot of the glacier it is about two miles(3.2 km.) up to the base of Mumm Peak. A better way to go is toclimb up the mountain side 2,000 feet and cross Hitka Pass, a dividebetween Mumm Peak and Hitka Mountain. The locality is high upwhere rain, fog, and snow squalls may be expected nearly every dayof the year.The fauna includes the species described in this paper, also a speciesof PlanoUtcs (annelid trail), Cystid ? sp. undt., Hyolithes sp. undt..and Hymcuocaris sp. undt. These, with the new species, make up asubfauna in the upper portion of the Lower Cambrian that has notbeen found elsewhere. It is marked by the absence of Olcnelliiscanadensis Walcott and Protypns fieldensis Walcott, the typical formsof the upper part of the Lower Cambrian section along Kicking HorsePass.There is undoubtedly a larger fauna to be obtained from theOleiiellus trucmani zone, but to find it will require a camp near thelocality on Hitka Pass and thorough collecting under adverseconditions. DESCRIPTION OF SPECIESMICKWITZIA MURALENSIS, new speciesPlate 50, figs. 10, II ; plate 51, figs. 1-6; plate 52, fig. iThis species differs from Mickzvitzia monilifera Linnarsson ^ inhaving a less elevated apex on the ventral valve, a varying positionof the apex, and in being in general more transverse.The shell is built up of several layers or lamellae that give it thick-ness and strength. The outer surface is fairly well shown by figure 6,plate 51. It is formed of fine, concentric, minutely undulating andinosculating ridges that are crossed by low, irregular radiatingridges. There is also a pitted appearance resulting from the hollowsbetween the ridges. On many shells there appear to be true punctjethat penetrate through the outer layer of the shell. The inner layersare marked by fine concentric and radiating lines.Monogr. U. S. Geol. Survej^ Vol. 51, 1912. pi. 6, figs, i, la-n.
NO. II NEW UnVER CAMBRIAN SUBFAUNA 3IIThe largest shell in the collection has a diameter of 46 mm. ( pi. 5 1,fig- 4)-Specimens of the shell are abundant as casts and impressions in thesiliceous shale. The original shell has disappeared, but from what weknow of the shell of Mickivit::.ia inonUifcra, it was probably formed ofcalcivun phosphate.One other American species of Alickzvitcia is known, il/. occidcnsWalcott.^ The punctate surface is much like that of M. muralciisis,but the form as far as known is not similiar.Formation and locality.—Lower Cambrian : (6ik) Mahto forma-tion ; dark, hard siliceous shale ; northeast base of Mumm Peak above]\Iural Glacier on west side of Hitka.Pass, 6 miles (9.6 km.) in adirect line north of the summit of Robson Peak and northwest ofYellowhead Pass, in western Alberta, Canada.LINGULELLA CHAPA, new .speciesPlate 50, figs. 4-9In form this species is not unlike Lingulella schuchcrti (Walcott)"^from the Lower Cambrian of New York. It differs in having a moreacuminate ventral valve, and possibly in other details not shown bythe rather poor specimens of L. schucherti. Several species ofLingulella from the Upper Cambrian have nearly the same outlineof the valves as those of L. chapa, notably L. randomensis f Walcott)^and L. mosia osceola (Walcott).'* Comparison may also be made withthe broader forms of L. perattenuata (Whitfield).' Linguella chapais distinguished by the very strong vascular canals of the ventral valve(fig. 6) and the shallow median sinus of the dorsal valve (figs. 4, 8,and 9)
.
The average length of the ventral valve is from 6 to 7 mm. Thedorsal valve is about one-sixth shorter than the ventral.Specimens of this species occur in such large numbers on partingsin the shale as nearly to cover the surface, or they may be scatteredabout among other brachiopods and fragments of trilobites.The specific name is taken from Chapa (beaver), the name of thehigh point at the foot of Mural Glacier where the first specimens ofthis species were found in a block of shale lying on the glacier.
^ Alonogr. U. S. Geol. Survey, Vol. 51, 1912, p. 3JI, pi. 6, fig. 4.
'Idem, pi. 21, fig. 6.
''Idem, pi. 21, figs. 5, Sa.
* Idem, pi. iS, figs. 2, 2a-c.^Idem, pi. 21, figs. ic-d.
312 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5/Formation and locality.—Lower Cambrian (6ik) Mahto forma-tion ; dark, hard siliceous shale ; northeast base of Mumm Peak aboveMural Glacier on west side of Hitka Pass, 6 miles (9.6 km.) in adirect line north of summit of Robson Peak and northwest of Yellow-head Pass, in western Alberta, Canada.LINGULELLA HITICA, new speciesPlate 50, figs. 1-3This species is represented by a number of compressed valves partlyflattened in the shale. The outer surface has concentric strise andlines of growth, and the shell is built up of several layers of what wasprobably calcareo-corneous material arranged as in typical Obolinse.''The average size and appearance of the valves are shown by fig-ure I, plate 50. A few ventral valves have a length of 13 mm., butthe average is about 10 mm.In outline of valves and general appearance, this species is similarto Lingulclla hella (Walcott).^ It is so highly improbable that aLower Cambrian species of the Cordilleran sea could persist untilthe close of Cambrian time in the Atlantic Province that I do not thinkit advisable to identify the two widely separated forms as belongingto the same species.There are no Lower Cambrian forms that seem to be similar toL. hitka.The specific name is taken from the Indian name Hitka (brown),a name applied to the mountain that rises on the east side of the ravinein which the specimens of L. hitka were found.Formation and locality.—Lower Cambrian : (6ik) Mahto forma-tion ; dark, hard siliceous shale ; northeast base of Mumm Peak aboveMural Glacier on west side of Hitka Pass, 6 miles (9.6 km.) in a directline north of summit of Robson Peak and northwest of YellowheadPass, in western Alberta, Canada.OBOLELLA NUDA, new speciesPlate 52, figs. T,-7The first impression given by the shells of this species is that theyare closely allied to Oholella atlaiiiica Walcott.' They have about thesame size and form. They differ in having a flattened median space,
^ Monogr. U. S. Geol. Survey, Vol. 51, 1912, p. 371.
^ Idem, pi. 19, figs. 2, 2a-q; pi. 36, fig. 4.
" Idem, pi. 55, figs. I, la-i.
NO. II NEW LOWER CAMBRIAN SUBFAUNA 313
occupying- a little more than one-third of the surface that extendsfrom the apex of the valves to the front margin. The casts of theinterior of the valves show the cardinal area, main vascular sinuses,and the form of the visceral area.The average size of the valves is from 4 to 6 mm. in diameter.As far as can be determined from the casts of the valves which arecompressed in the shale the shells were thinner than those of Oholellachromatica Billings,' and had a somewhat different arrangement ofthe various features of the interior of the valves. The mode of oc-currence is much like that of O. chromatica and O. atlantica, as thevalves occur in large numbers on partings of the shale. If specimenscan be found in a calcareous deposit, much closer comparison may bemade with other species.Formation and locality.—Lower Cambrian : (6ik) Mahto forma-tion ; dark, hard siliceous shale ; northeast base of Mumm Peak aboveMural Glacier on west side of Hitka Pass, 6 miles (9.6 km.) in a directline north of summit of Robson Peak and northwest of YellowheadPass, in western Alberta, Canada.OBOLELLA cf. CHROMATICA BillingsPlate 52, fig. 2Obolella chromatica Billings. 1861. For synonymy see Monogr. U. S. Geol.Survey, Vol. 51, 1912, p. 591.This form is represented by casts of the exterior and partialinteriors of several valves of a shell that is very much like what O.chromatica might be if preserved in the same siliceous, shaly matrix.The shell is larger than that of Obolella niida (p. 312) as it averages8 mm. in diameter, and the valves are evenly convex and not flattenedas is the case with 0. niida.Formation and locality.—Lower Cambrian : (6ik) Mahto forma-tion ; dark, hard siliceous shale ; northeast base of Alumm Peak aboveMural Glacier on west side of Hitka Pass, 6 miles (9.6 km.) in adirect line north of summit of Robson Peak and northwest of Yellow-head Pass, in western Alberta, Canada. ^HOLMIA ? MACER, new speciesPlate 54, fig. IThis species is characterized by its proportionally large cephalon*and narrow thorax, in these respects resembling Holmia kjcntlfi.'
^ Monogr. U. S. Geol. Survey, Vol. 51, 1912, p. 591, pi. 54, figs, i, ui-i.
- Smithsonian Misc. Coll., Vol. 53, No. 6, 1910, pi. 27, fig. 7.
314 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57
It differs, however, from the latter in many details of the cephalon andthorax. The cephalon more closely resembles that of Holmia roivci 'in its glabella and strong, rounded marginal border, but it does nothave the strong occipital spine of the latter. There are 13 segmenfsof the thorax preserved in the type specimen. The ends of the plurallobe terminate rather abruptly in sharp, backward-pointing spines, inthis respect resembling Holmia kjerulft.Nothing is known of the posterior segments of the thorax or thepygidium.The type and only specimen of this species was discovered byProfessor H. Justin Roddy of the State Normal School, Millersville,Pennsylvania, who presented it to the United States NationalMuseum.Formation and locality.—Lower Cambrian: (i2v) Upper portionof York formation, 2 miles (3.2 km.) north of the citv of Lancaster,near Fruitville, Lancaster County, Pennsylvania.WANNERIA OCCIDENS, new speciesPlate S3, fig. 2Of this species only a single cephalon occurs in the collection.This has the characteristic short palpebral lobe and elongate bossbetween the latter and the dorsal furrow adjoining the glabella. Thesides of the glabella are subparallel opposite the two posterior pairsof glabellar furrows. The margin of the cephalon is broad and slightlyrourided. A short occipital spine that is about one-fourth the length ofthe cephalon projects backward from the center of the occipital ring.The cephalon differs from that of Jl'anneria zvalcottanus' in beingproportionally more elongate, and in the presence of an occipital spineinstead of an occipital node or tubercle.It differs from Olcnellus gilbcrti" in its small, short palpebral lobeand strong marginal rim, also in the presence of an occipital spine.The small palpebral lobe and tubercle back of it suggest Olcnelluscanadensis* but the other parts of the cephalon differ.Formation and locality.—Lower Cambrian: (6ik) ]\Iahto forma-tion ; dark, hard siliceous shale ; northeast base of Alumm Peak aboveMural Glacier on west side of Hitka Pass, 6 miles (9.6 km.) in a
^ Smithsonian Alisc. Coll., Vol. 53, No. 6, igio, pi. 29.
^ Idem, pi. 30.
^ Idem. pi. 36.
* Idem, pi. 38, figs. 4-6.
NO. II NEW LOWER CAMBRIAN SUBFAUNA 315direct line north of summit of Robson Peak and northwest of Yellow-head Pass, in western Alberta. Canada.CALLAVIA EUCHARIS, new speciesPlate 53, fig. IThis fine species is represented by one entire specimen. It has 23segments in the thorax, and a very small and narrow pygidium. Thecephalon is very much like that of Callavia perfecta, but the thoracicsegments are proportionally narrower and there are six more ofthem.The dorsal shield has a length of 38 mm., with a width of 30 mm.at the back of the cephalon.Traces of the surface show it to have been ornamented with a finenetwork formed of low, sharp ridges such as is found on most speciesof the JNIesonacidas.Formation and locality.—Lower Cambrian : (6ik) Mahto forma-tion ; dark, hard siliceous shale ; northeast base of Mumm Peak aboveIMural Glacier on west side of Hitka Pass, 6 miles (9.6 km.) in adirect line north of summit of Robson Peak and northwest of Yellow-head Pass, in western Alberta, Canada.CALLAVIA PERFECTA, new speciesPlate 53, figs. 3-5This species recalls Callavia crosbyi Walcott.^ It differs in havinga more tapering glabella, smaller palpebral lobes, and in the absenceof a strong occipital spine. The cephalon of Callavia burri Walcott ^is very similar, but, as may be seen by comparing figures 9 and 10 ofthe latter with figure 5, plate 53, of Callaz'ia perfecta, the palpebrallobes are larger and farther out from glabella.Callavia perfecta has 17 thoracic segments and a very small, narrowpygidium. The exterior surface has a very minute fretwork of linesthat is difficult to be seen even with a strong lens, in this respectdiffering from the associated Callavia eucharis.Formation and locality.—Lower Cambrian : (6ik) Mahto forma-tion ; dark, hard siliceous shale ; northeast base of Mumm Peak above]\Iural Glacier on west side of Hitka Pass, 6 miles (9.6 km.) in adirect line north of summit of Robson Peak and northwest of Yellow-head Pass, in western Alberta, Canada.
' Smithsonian Misc. Coll., Vol. 53, No. 6, 1910, p. 284, pi. 28.
"Idem, pi. 28. figs. 9 and 10.
3l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57OLENELLUS TRUEMAKI, new speciesPlate 54, figs. 2-10This species differs from Olcnellus flwmpsoiii (Hall)* and 0. ,i^;7-bo'ti Meek ' in having shorter palpebral lobes and eyes, smaller andshorter plural lobes of the third thoracic segment, and in having amore coarsely reticulated outer surface of the test, in the latter char-acter resembling 0. reticulatus Peach.' It differs from the latter andO. lapzi'orthi Peach ^ in having a stronger rim about the cephalon, theanterior glabellar lobe closer to the frontal rim, and a broader thoraxand smaller, shorter pleural lobe on the third segment. The thirdthoracic segment is distinctly larger than the others in all specimens
;
proportionally it decreases in size from the young to the largest adults,as may be seen by comparing figure lo and figure 2, plate 54.The hypostoma has a denticulated posterior margin similar to thatof Pccdciimias transitans' and Wanneria liaUi." It appears to havebeen attached to the doublure by its anterior margin and not by aprocess as in Pccdemnias transitans.The specimens of this species are abundant and usually well pre-served. The largest cephalon collected has a width of 50 mm. and alength of 22 mm., and the entire dorsal shield has a length of 56 mm.exclusive of the spine-like telson.The specific name is given in memory of Dr. J. i\I. Trueman, of theGeological Survey of Canada, a most promising young geologist whowas drowned in a canoe accident that occurred (June 24, 1912) whilehe was showing me the Huronian fossil-bearing limestones of Steep-rock Lake, Ontario, Canada.Forwation and locality.—Lower Cambrian: (6ik) ]\Iahto forma-tion ; dark, hard siliceous shale ; northeast base of Alumm Peak aboveJMural Glacier on west side of Hitka Pass, 6 miles (9.6 km.) in adirect line north of summit of Robson Peak and northwest of Yellow-head Pass, in western Alberta, Canada.
^ Smithsonian Misc. Coll., Vol. 53, No. 6, igio, pi. 35.
" Idem, pi. 36.
^ Idem, pi. 39.* Idem, pi. 39.
' Idem, pi. 34, fig. 8.
" Idem, pi. 31, fig. 9.

3l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57
DESCRIPTION OF PLATE 50 PAGELingulella hitka Walcott 312Fig. I. (Natural size.) Group of shells flattened on surface of shale.(Locality 6ik.) U. S. National Museum, Catalogue No.60067.2. (X 2.) A ventral and a dorsal valve enlarged from fig. i.3. (X 2.) A dorsal valve that occurs on fig. i.Lingulella chapa Walcott 311Fig. 4. (X 3-) A group of shells on surface of shale. (Locality 6ik.)U. S. National Museum, Catalogue No. 60068.5. (X 4) A small uncompressed ventral valve. (Locality 6ik.)U. S. National Museum, Catalogue No. 60069.6. (X 4-) Natural matrix of the interior of a ventral valve.(Locality 6ik.) U. S. National Museum, Catalogue No.60070.7. (X 4-) A partly exfoliated ventral valve. (Locality 6ik.)U. S. National Museum, Catalogue No. 60071.8. (X 4-) A small, uncompressed dorsal valve. (Locality 6ik.)U. S. National Museum, Catalogue No. 60072.9. (X 4) A broader form of the dorsal valve than that repre-sented by fig. 8. (Locality 6ik.) LT. S. National Museum,Catalogue No. 60073.Mickwitzia muralensis Walcott. (See Plates 51 and 52) 310Fig. id. (X 3-) Flattened dorsal valve with excentric apex. (Locality6ik.) U. S. National Museum, Catalogue No. 60093.II. (X 6.) Area about apex and posterior margin enlarged toillustrate surface character. (Locality 6ik.) U. S. Na-tional Museum, Catalogue No. 60094.The specimens represented by figs, i-ii are from locality 6ik.Lower Cambrian : Mahto formation ; dark, hard siliceous shale,northeast base of Mumm Peak above Mural Glacier on the west sideof Hitka Pass, 6 miles (9.6 km.) in a direct line north of summit ofRobson Peak and northwest of Yellowhead Pass, in western Alberta,Canada.
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. It, PL. 60
11BRACHIOPODA


320 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57
DESCRIPTION OF PLATE 51 PAGEMickzvitsia muralcnsis Walcott. (See Plates 50 and 52) 310Fig. I. (X2.) Small ventral valve with submarginal apex. (Locality6ik.) U. S. National Museum, Catalogue No. 60095.2. (Natural size.) Small ventral valve vvnth apex nearly at itscenter. (Locality 6ik.) U. S. National Museum, Cata-logue No. 60096.3- (X 3-) Ventral valve preserving much of its original con-vexity. (Locality 6ik.). U. S. National Museum, Cata-logue No. 60097.4. (Natural size.) Large ventral valve with apex near its centerand small dorsal valve on same piece of shale. (Locality6ik.) U. S. National Museum, Catalogue No. 60098.5. (X -'•) Dorsal valve flattened in the shale. (Locality 6ik.)U. S. National Museum, Catalogue No. 60099.6. (X 8.) Enlargment of exterior surface of a ventral valve.(Locality 6ik.) U. S. National Museum, Catalogue No.60100.The specimens represented by figs. 1-6 are from locality 6ik.Lower Cambrian : Mahto formation ; dark, hard siliceous shale,northeast base of Mumm Peak above Mural Glacier on the west sideof Hitka Pass, 6 miles (9.6 km.) in a direct line north of summit ofRobson Peak and northwest of Yellowhead Pass, in western Alberta,Canada.
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. n, PL. 61
BRACHIOPODA


322 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57
DESCRIPTION OF PLATE 52 PAGEMickwitzia mitralcnsis Walcott. (See Plates 50 and 51) 310Fig. I. (Natural size.) Ventral and dorsal valves flattened in theshale. (Locality 6ik.) U. S. National Museum, CatalogueNo. 60101.Obolclla cf. chromatica Billings 313Fig. 2. (Natural size.) Natural cast of both ventral and dorsal valves.(Locality 6ik.) U. S. National Museum, Catalogue No.60073.Obolella nuda Walcott 312Fig. 3. (X4-) Ventral valve. (Locality 6ik.) U. S. National Mu-seum, Catalogue No. 60074.4. (X 4-) A ventral and a dorsal valve. (Locality 6ik.) U. S.National Museum, Catalogue No. 60075.5. (X 4-) Natural cast of the interior of a ventral valve.(Locality 6ik.) U. S. National Museum, Catalogue No.60076.6. (X 4-) Natural cast of the interior of a dorsal valve. (Locality6ik.) U. S. National Museum, Catalogue No. 60077.7. (X 4-) Natural casts of the interior of ventral and dorsalvalves. (Locality 6ik.) U. S. National Museum, CatalogueNo. 60078.The specimens represented by figs. 1-7 are from locality 6ik.Lower Cambrian : Mahto formation ; dark, hard siliceous shale,northeast base of Mumm Peak above Mural Glacier on the west sideof Hitka Pass, 6 miles (9.6 km.) in a direct line north of summit ofRobson Peak and northwest of Yellowhead Pass, in western Alberta,Canada.
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. n, PL. 62
^^.tv
r .*•"' ^-^
6
ii^sSS^'iftj
..•<-4'-
'• N'*^^^,
BRACHIOPODA


324 SMITHSONIAN IMISCELLANEOUS COLLECTIONS VOL. 57
DESCRIPTION OF PLATE 53 PAGECallavia eucharis Walcott 315Fig. I. (X 2.) Type specimen of the species. (Locality 6ik.) U. S.National Aluseum. Catalogue No. 60079.
JVauiieria occidcns Walcott 314Fig. 2. (Natural size.) Type specimen of the cephalon of the species.(Locality 6ik.) U. S. National Museum, Catalogue No.60080.Callavia perfecta Walcott 315Fig. 3. (X 2.) Type specimen of the species. (Locality 6ik.) U. S.National Museum, Catalogue No. 60081.4. (Natural size.) Specimens of the cephalon found in a partingof the shale. (Locality 6ik.) LI. S. National Museum,Catalogue No. 60082.5. (Natural size.) A large cephalon flattened in the shale.(Locality 6ik.) \]. S. National Museum, Catalogue No.60083.The specimens represented here by figs. 1-5 are from locality 6ik.Lower Cambrian : Mahto formation ; dark, hard siliceous shale,northeast base of Mumm Peak above Mural Glacier on the west sideof Hitka Pass, 6 miles (9.6 km.) in a direct line north of summit ofRobson Peak and northwest of Yellowhead Pass, in western Alberta,Canada.
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 57, NO. 11, PL. 53


326 SMITHSOXIAN MISCELLANEOUS COLLECTIONS VOL. 57
DESCRIPTION OF PLATE 54 PAGEHoliiiia ? niacer Walcott 313Fig. I. (X 3-) Type specimen of the species. (From locality i2v.)Lower Cambrian shale, Fruitville, Lancaster County, Penn-sylvania. U. S. National Museum, Catalogue No. 60092.Olenellus truemani Walcott 316Fig. 2. (X 2.) Surface of shale with two compressed, nearly entiredorsal shields and a small cephalon. (Locality 6ik.) \J. S.National Museum, Catalogue No. 60084.3. (X 2.) Compressed and slightly distorted hypostoma. (Local-ity 6ik.) U. S. National Museum, Catalogue No. 60085.4 and 5. (X S-) Two small hypostomas. (Locality 6ik.) U. S.National Museum, Catalogue No. 60086.6. (Natural size.) Cephalon with outer test of cheeks exfoliatedso as to show casts of radial canals. (Locality 6ik.) U. S.National Museum, Catalogue No. 60087.7. (Natural size.) Broad, flattened dorsal shield with enlargedthird thoracic segment. (Locality 61k.) LT. S. NationalMuseum, Catalogue No. 60088.8. (X 2.) A small, almost entire dorsal shield. (Locality 6ik.)U. S. National Museum, Catalogue No. 60089.g. (X 2.) A small cephalon preserving much of its original con-vexity. The attached thoracic segments are more or lessdisplaced. (Locality 6ik.) U. S. National Museum, Cata-logue No. 60090.10. (X 2.) Small, nearly entire, undistorted dorsal shield withlarge third thoracic segment. (Locality 6ik.) U. S.National Museum, Catalogue No. 6oogi.The specimens represented by figs. 2-10 are from locality 6ik.Lower Cambrian: Mahto formation; dark, hard siliceous shale,northeast base of Mumm Peak above Mural Glacier on the west sideof Hitka Pass, 6 miles (9.6 km.) in a direct line north of summit ofRobson Peak and northwest of Yellowhead Pass, in western All^erta,Canada.
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 67, NO. 11, PL. 54