SMITHSONIAN MISCELLANEOUS COLLECTIONSPART OF VOLUME LIIICAMBRIANGEOLOGY AND PALEONTOLOGY No. 2.—CAMBRIAN TRILOBITESWith Six Plates BYCHARLES D. WALCOTT No. 1805 CITY OF WASHINGTONPUBLISHED BY THE SMITHSONIAN INSTITUTIONApril 25, 1908 CAMBRIAN GEOLOGY AND PALEONTOLOGYNo. 2.—CAMBRIAN TRILOBITESBy CHARLES D. WALCOTT(With Six Plates)CONTEXTS PageBurlingidce, new family 14Burlingia, new genus 14Burlingia hectori, new species 15Alhertella, new genus ,. 18 " helenct, new species 19 " boszvorthi, new species 22Oryctocara, new genus 23 " geikiei, new species 23Zacanthoides idahocnsis, new species 26Neoleniis iniJatus, new species 30 " inteniicdiiis, new species 34 " ' pugio, new variety 35" supcrhus, new species 36Bathynriscus ornattis, new species 39 The monograph on the Cambrian Brachiopoda,^ upon which I havebeen working- for so long, is about ready for the press, and attentionis now being given to the preliminary study of some of the AmericanCambrian trilobites. If students and collectors in any country knowof interesting or new forms of Cambrian or Lower Ordovician trilo-bites, or of more perfect specimens representing previously describedforms, I should very much like to have their cooperation in makingthis investigation as thorough and complete as possible.This is the first of a series of brief papers that will be publishedas new' material of interest is worked up. The classification of Dr.Charles E. Beecher" will be followed, in the preliminar}- studies atleast, with such modifications as may appear necessary during thecourse of the investigations. ^ To be published as Monograph LI of the U. S. Geological Survey.'American Jour. Sci., 4th ser., vol. iii, 1897. pp. 89-106, 181-207. 13 14 SMITHSOXIAX MISCELLAXEOUS COLLECTIOXS VOL. 53Order PROPARIA BeecherBuRLixGiD.15, new familyDorsal shield small, elongate, broad oval in outline. Cephalonabout one-fourth the length, transversely semicircular : genal angleacute or spinose ; glabella with transverse lobes. Free cheeks small,separate. Facial sutures cut the margin in' front of the genal angles,extend in to the posterior portion of the eye lobe and outward fromthe anterior portion to the antero-lateral margin of the cephalon.Eyes of medium size, clearly defined.Thorax with fourteen segments in the one species preserving them ;pleura; with flat, straight furrows.Pygidium large, with strong axis and pleural lobes, or small andwith medium axis and pleural lobes.Stratigraphic Raxge.—Central portion of the Middle Cambrianto the Agiiosfiis pisifonnis zone of the Swedish Upper Cambrian.ObsErvatioxs.—This family includes the genera Biirlingia andSchmalcnsceia} The first is represented by entire specimens and thelatter by the cephalon, fragments of the thorax, and entire pygidia.The facial sutures and free cheeks relate Biirlingia to some forms ofthe Cheirurid?e, while the pygidium of Biirlingia recalls the simplepygidium of Paradoxidcs, and the pygidium of Schnuilcnsccia recallsthat of Aiuphioii. The flat, straight furrowed pleurae of the thoraxof Biirlingia recall the pleurse of Olenoidcs. The assemblage ofcharacters in Biirlingia and Schnialcnsccia clearly indicate a distinctfamily of the Proparia, more primitive than any other forms of thatorder. BURLINGIA, new genusDorsal shield small, elongate, broadly oval. Cephalon semicir-cular; one-fourth the length of the entire shield; genal angles withspines ; cranidium- with anterior and posterior limbs that extend out-ward from the glabella to the outer margin ; glabella slightly convex,with indications of lobes. Free cheeks subquadrangular, small.Facial sutures extend from in front of the genal angles inward tothe eyes and then obliquely outward and forward, cutting the antero-lateral margin. Eyes of medium size.Thorax with fourteen segments ; pleurae with a flat, direct furrow ; pleurae extended into backward-curving, falcate extremities. ' Moberg, 1903, Meddelande fran Lunds CtCoI. Mineral. Inst. No. 5 (Geol.Foren. i Stockholm Forhandlingar, Bd. xxv. Haft 2, 1903, No. 219), p. 96. " The cranidium includes all portions of the cephalon except the free checksand eye lobes. CAMBRIAN TRILOBITES WALCOTT 1 5 Pygidium small, elongate, without defined segments.Genotype.—Burlingia hcctori, new species.(Observations.—This genus is represented by a single species fromthe central portion of the Middle Cambrian fauna. The only formwith which it can be directly compared is Schiiialeiisceia ^loberg,^which is represented by specimens of the cranidium, pygidium. andfragments of the thoracic segments belonging to a single species.The cranidium of Schuialenseeia differs in having a convex glabelladivided into four lobes by four transverse furrows, and in thepresence of a defined occipital segment. The fragments of thethorax illustrated by Dr. Moberg (1903, pi. iv) and his description ofthem indicate that the pleurae were flattened and marked by shallow,direct furrows similar to those on the pleurae of Burlingia. With thepresent information, it is in the pygidium that the great difference inthe two genera is found. The pygidium of Schuialenseeia is largeand it has a strong axial lobe divided into a number of segments ; thepleural lobes are broad and marked by numerous backward-curving,fiat furrows much like those of the thoracic segments of Burlingia.The pygidium of Burlingia is small and apparently without segmentsor pleural lobes; it is a simple plate as in Paradoxides.Dr. Moberg ( 1903, p. 100) has noted the resemblance between thedirection of the facial sutures of Schuialenseeia and those of somegenera of the Cheirurid^e and Encrinuridse, while the broad anteriormargin of the head suggests some of the Conocoryphidas ; he con-cludes that these resemblances have little value, as the other parts ofthe shield differ so largely from the representatives of these genera.In this I agree with him. The two genera are unlike all other trilo-bites and form a family type by themselves.The genus is named after Mr. Lancaster D. Burling, of the UnitedStates National ^luseum. who found the only three nearly entirespecimens of this interesting trilobite.BURLINGIA HECTORI, new speciesPlate i, Fiai-RE 8Dorsal shield small; longitudinally broad oval; slightlv convex.Cephalon one-fourth the length of the complete dorsal shield, semi-circular in outline, with genal angles prolonged into short slenderspines that scarcel\- extend beyond the extremity of the first or ante-rior thoracic segment ; the posterior margin of the cephalon is nearly ' Moberg. 1903, Meddelande fran Lunds Geol. Mineral. Inst. No. 5 ( Geol.Koren. i Stockiiolm Forhandlingar, Bd. xxv. Haft 2. 1903, No. 2ig), pp. 93-102,pi. IV. l6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53transverse except at the axial lobe, where it arches slightly forward ; the slope from the central portion of the cephalon to the margin isunbroken by any furrow and there is no clearly defined or raised rim.Cranidium with a broad campanulate frontal limb that extends fromthe anterior base of the eyes obliquely outward and forward anddirectly forward from the glabella to the outer margin of the cepha-lon ; the posterior limbs, on their inner side, occupy the space betweenthe posterior base of the eye and the posterior margin of thecephalon and extend outward to the lateral margin with a graduallyincreasing width ; there is no fixed cheek between the palpebral lobeand the glabella; palpebral lobe about one-third the length of thecephalon and situated a little back of the center ; it is slightly elevatedalong the outer margin and slopes toward the dorsal furrow nextto the glabella. Glabella about three-fifths the length of the cepha-lon; it has subparallel sides up to the front of the eyes, where thesides curve inward and unite to form an obtusely rounded outline;in front the glabella merges into the frontal limb, so as to make itdifficult to indicate a line of division between them; the glabella isgently convex and more or less clearly marked by a narrow medianridge, and, on each side of the ridge, two pits that indicate transversefurrows, very much as do the pits on the glabella of Oryctoccplialiis^;there is no trace of an occipital furrow or segment. Free cheekssubquadrangular in outline; on their inner margin they support thevisual surface of the eye and from there slope gently to the outermargin. The facial sutures cut the lateral margin of the cephalonsome distance in front of the genal angle and extend wth a littlebackward curvature to the posterior base of the eye; after curvingover the eye lobe they extend obliquely forward at an angle of about50° to the margin.Thorax with fourteen segments ; the first is nearly transverse, buteach succeeding pleural lobe bends back a little more than the onepreceding it, so that the pleural lobe of the posterior segment is bentback parallel to the side of the pygidium ; the central axis of thethorax is gently convex, with a low median ridge that rises into aminute node on the two anterior segments ; it gradually widens fromthe first to the seventh segment, and then narrows a little at eachsegment back to the pygidium ; the pleural lobes are flattened betweenthe axial lobe and the angle where the pleurse bend more or lessbackward ; each pleura has a broad, shallow, direct furrow thatextends from the inner end out to the backward curving portion ofthe pleur?e ; the edge of the furrow and of the segment is marked byMValcott, 1886, Bull. U. S. Geol. Survey, No. 30. p. 210. CAMBRIAN TRILOBITHS—WALCOTT I7 a narrow thread-like ridge ; the pleiine terminate in falcate extremi-ties, some of which, on the two anterior segments, appear to have averv short, fine spine at the posterior termination of each pleura.Pygidium a narrow, elongate, moderately convex, central platewithout defined segments or pleural lobes ; it has a small node at theanterior third of its length. None of the specimens show the pos-terior margin ; it may have been a single, broad spine or it may haveterminated with a slightl\" arched posterior margin.The outer surface of the dorsal shield appears to have beenminutely granular or smooth.Dimensions.—The most perfect specimen of the dorsal shield hasa length of 7 mm. ; greatest width, 5 mm. The other dimensions areas follows : Cephalon : nii;iLength 2 . 25Width at posterior margin 4-74Thorax : Length 1 . 75Greatest width 5 . 00Axial lobe, greatest width i . 50Pleural lobe, greatest width i . 75Pj'gidium : Length to line of contour of dorsal shield i .50Width at anterior end 75Observations.—This interesting trilobite has a cephalon muchlike that of Schiiwloisecia amphiomira Moberg,^ but it dififers in de-tails, and the pygidium is quite unlike that of Dr. Moberg's species ; the furrows and ridges on the pygidium of the latter are very similarto those of the thorax of Bitrlingia.The stratigraphic horizon of this species is 2,400 feet above theLower Cambrian or Olenellus fauna and 2,600 feet below the UpperCambrian fauna. It is associated with Zacanthoidcs spiiwsus, Ogy-gopsis klotzi, Oryctocephalus rcynoklsi, Bathyuriscus rotundatns,Bathyiiriscus oniatus, and other species of the Ogygopsis kJotzifauna of ]\Iount Stephen.The specific name is given in recognition of Sir James Hector, theCanadian geologist and explorer who discovered the Hector orKicking Horse Pass in 1858.Formation and Locality.—Middle Cambrian: Ogygopsis shaleof the Stephen formation, 2,400 feet (731.5 m.) above the Lower ^ Moberg, 1903, Meddelande fran Lunds Geol. Mineral. Inst. No. 5 (Geol.Foren. i Stockholm Forhandlingar, Bd. xx\^ Haft 2, 1903, No. 219), pi. iv, figs.I and 2. l8 SMITHSOXIAX MISCiy,LAXKOUS COLLECTIONS \0L. 53Cambrian and 2,600 feet (792.5 m.) below tbe Upper Cambrian;northwest slope of Alount Stephen, 3,000 feet (914.4 m.) above theKicking Horse River, above Field, on the Canadian Pacific Railway.British Columbia, Canada.Order OPISTHOPARIA BeecherFamily Paradoxid.eALBERTELLA, new genusDorsal shield elongate-ovate. Cephalon large, semicircular in out-line, about one-fourth the length of the dorsal shield ; genal anglesextended into spines : cranidium subcjuadrangular in outline, withlong palpebral lobes and narrow fixed cheeks ; palpebral lobes elon-gate, with outer rims continued across the fixed cheeks as narrowocular ridges ; glabella subquadrilateral in outline, with short lateralfurrows ; strong occipital ring. The facial sutures cut the posteriorborder within the genal angles and pass inward and slightly forwardto the base of the eyes, thence about the palpebral lobe, and forwardwith slight curvature to the front margin.Thorax with seven segments ; pleurae terminating in short spines,those of the third or fourth segment in longer spines ; pleural furrowwith broad inner end largely filled in by an elongated tubercle.P3'^gidium large, with central axis divided into several rings, andwith the first, or first and second combined, anterior, anchylosed seg-ments extended across the border into a long spine on each side.Genotype.—AlhcvtcUa hclciia, new species.Stratigraphic Range.—Upper beds of Lower Cambrian.Geographic Distribution.—Western Alberta, near the line of theCanadian Pacific Railway, Canada, and northern ]\Iontana, in theLewis and Clark Forest Reserve.Observations.—AlbcrtcUa is a most interesting type of the orderOpisthoparia and family ParadoxidcC. It should first be com.pared withthe genus Zacanthoidcs Walcott,^ which, in the British Columbiasection, is first met with in strata 2,000 feet above the beds in whichAlhertcUa occurs. The cephalons of the tw^o genera are genericallythe same. The thoracic segments are of the same type, but the thirdor fourth segment of the thorax of AlbcrtcUa is extended into longpleural spines, and the thorax has seven instead of nine segments, asin Zacanthoidcs. The pygidium of AlhertcUa has a long, strongspine extending from the pleural lobes of the first, or first and secondcombined, anterior segments, and a smooth border otherwise ; the * Walcott, 1888, American Jour. Sci., 3d ser.. vol. xx.wi, p. 1(15. CAMBRIAN TKILOBITES WALCOTT I9pygidium of Zacanthoidcs has ^11 the pleural segments extended asspines directly across the border.The prominent differences between the two genera, then, are theextension in adult individuals of the third or fourth segment of thethorax in AlhcrtcUa, and the presence on the pygidium of one pair ofspines instead of many spines, as in Zacanthoidcs.The extension of the third segment of the thorax occurs in thegenera Oloicllus Hall and Mcsonacis Walcott,^ and the spinoseextension of the pleural elements of the pygidium occurs in Para-boliiia Salter,- Hysfcrolcinis Moberg,^ and other genera, but theseother genera differ in so many other characters that it is unnecessaryto make comparisons between them and AlbcrtcUa.ALBERTELLA HELENA, new speciesPr.ATE 2. Figures i-yDorsal shield of niedium size ; with the exception of spines, longi-tudinally elongate-ovate ; moderately convex. Cephalon semicircularin outline, one-third the length of the dorsal shield ; marginal borderof medium width, slightly convex, delimited from the cheeks by asharp, shallow furrorw, and continued at the genal angles directlyinto long, slender spines that extend outward and backward to a lineback of the union of the thorax and pygidium ; posterior bordernarrow at the inner end next to the dorsal furrow, a little wider atthe facial sutures, and arching a little forward before merging intothe outer border at the genal spine ; the posterior border is delimitedfrom the cheeks by a narrow, shallow furrow that begins oppositethe center of the occipital segment, and, arching forward a very little,passes into the furrow within the outer border. Cranidium convex,subquadrangular in outline exclusive of the extension of its postero-lateral limbs ; the latter are of medium width, with nearly one-half oftheir area occupied by the posterior furrow and border. Fixedcheeks at the palpebral lobe one-third the width of the glabella ; posteriorly they merge into the postero-lateral limbs ; anteriorly thevpass directly forward to the interborder furrow ; palpebral lobenarrow, elongate, about three-fifths the length of the cephalon. M'Valcott, 1891, Tenth Ann. Kept. U. S. Geo!. Survey, pis. i.xx.xii, i,.\.\.\ni,Lwxiv. L.xxxv, and i.xxxvii. - Moberg and Moller, i8g8, Meddelande fran Lunds Geo!. Faltklubb, No. 3(Geol. Foren. i Stockholm Forhandlingar, Bd. xx, Haft 5, 1898, No. 187), pis.xn and xni.^Moberg, 1898, INIeddelande fran Lunds Geol. Faltklubb, No. 5 (Geol. Foren.i Stockholm Forhandlingar, Bd. xx, Haft 6, 1898, No. 188), pi. xvii, figs. 1-9. 20 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53bordered by a narrow, rounded rgii that is continued obliquelyinward and forward, as an ocular ridge, across the fixed cheekto the dorsal furrow opposite the anterior pair of glabellar fur-rows. Glabella, including occipital ring, subquadrilateral, withsides slightly curved inward and front broadly rounded, moderatelyconvex ; the average sized glabella is marked by a pair of short,shallow- furrows that extend obliquely inward and backward aboutone-third the distance across the glabella, and a pair of nearly trans-verse, short furrows that divide it into a short lobe on each side and alarge anterior frontal lobe ; the latter has a short, shallow furrowon each side about midway of its length that extends directly in-ward toward the central third of the width of the glabella ; theglabella of a crandidilim 23 mm. in length has a pair of deep,oblique, posterior furrows, and, in advance of them, four pairs offaint, short, nearly transverse furrows, the posterior pair of whichare between the strong, oblique, posterior furrows and the longitu-dinal, median third of the glabella ; a small dorsal shield with acephalon 1.3 mm. in length, shows the oblique, posterior glabellarfurrow and two pairs of the anterior furrows ; occipital furrowstrong, sharply defined, and curving forward at its ends ; occipitalring strong, rounded, arching slightly backward with its antero-lateral angle extending forward. Free cheeks slightly convex, withthe body rising from the inter-border furrow to the base of theelongate, low eye lobe. The facial sutures cut the posterior marginwithin the middle third of the distance from the dorsal furrow tothe outer margin ; they curve gently outward and then inwardacross the border, and thence with a slight sigmoid curve to thebase of the eye lobe; arching over the latter, they extend forwardwith a slight outward arching to and across the frontal border, soas to cut the frontal margin within a longitudinal line drawn for-ward from the outer margin of the palpebral lobe.Thorax with seven nearly transverse segments ; axial lobe convexand arching slightly backward ; a small, low node occurs at thecenter near the posterior margin, and a transverse, rounded, lowridge at each end next to the dorsal furrow ; the pleura is nearlystraight, somewhat flattened, and terminated by a sharp spine thatextends obliquely outward and backward a short distance, excepton the third segment, which has a strong spine extending back-ward nearly to a hue opposite the posterior third of the pygidium ; pleural furrow broad at the dorsal furrow and narrowing to itsend at the base of the terminal spine ; a rounded, elongate, subtri-angular tubercle occupies its inner half ; the anterior border of thepleura next to the dorsal furrow is a narrow, rounded ridge, which CAMBRIAN TRILOBITES—WALCOTT 21 widens gradually and passes directly into the terminal spine ; theposterior border is a narrow, rounded ridge that merges into thebase of the terminal spine.Pygidium moderately convex, about one-fourth of the length ofthe dorsal shield, elongate, semicircular in outline; axial lobe con-vex, divided by five shallow, narrow, transverse furrows into fiverings and a terminal section that is within the border ; pleural lobesmarked by the pleural furrows of four anchylosed segments thatmerge into the smooth border ; a slender but strong, long spine ex-tends from a strong base on each side of the p3^gidium; this spineappears to be the extension of the anterior anchylosed segment.Surface finely granulose, with scattered larger granules on smallspecimens.Dimensions.—A dorsal shield 40 mm. in length has the followingdimensions : Cephalon : mm.Length 13 • 5Width at posterior margin 31.5Thorax : Length 17 -oWidth at first segment 22 .Pygidium : Length 9-5Width 15-0Observations.—A dorsal shield 2.7 mm. in length, with a cepha-lon 2.3 mm. long, has a fixed cheek nearly as wide as the glabella,an eye lobe fully one-half the length of the cephalon, and the glabellaslightly expanded toward the front. A large cranidium, 23 mm.in length, has a glabella proportionally wider in front, and verystrong, posterior, oblique furrows.This species was first found in 1904, on Gordon Creek, OvandoQuadrangle, Montana, in argillaceous shales, a short distance abovethe supposed Flathead sandstones, in association wuthAcrothele colleni, new species,Wimanella simplex, new genus and new species,Olenopsis,Ptyclioparia. andBathynriscus, sp. a.The stratigraphic position of this subfauna was not determinedin Montana, owing to the break in the continuity of the section onGordon IMountain.The specific name is given in recognition of the discovery by Mrs. 22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53W'alcott, in 1907, of this species and the accompanying- subfaunaon Mount Bosvvorth, in the Canadian Rockies. Its position wasdetermined to be at the summit of the Lower Cambrian portion ofthe section. 2.450 feet below the Ogygopsis klotci fauna of MountStephen.The subfauna at the Blount Bosworth locaHt}' includesMicromitra {IphidcUa) zcapta, new f^pecies,Oboliis parz'its, new species,Acrothcle collcni, new species,JViinanclla simplex, new genus and new species,Albcrtclla boszy.'orthi, new species.Alhcrtella lielcna, new species, andB'athyuriscHS. sp. a.Formation and Locality.—Lower Cambrian: (i) Drift blockof siliceous shale on the south slope of Mount Bosworth. on the "Continental Divide," one mile east of Hector, on the CanadianPacific Railway, British Columbia, Canada; and (2) Wolsey argil-laceous shale, on Gordon Creek, 4 miles (2.5 km.) above its unionwith Danaher Creek, at the southeast foot of Gordon Mountain,Lewis and Clark Forest Reserve. Montana. U. S. A.ALBERTELLA BOSWORTHI, new speciesPlate t, Fig t -res 4-7This species diiiers from the associated Alhcrtella helciia in itscephalon, thorax, and pygidium. In the cephalon the eye and pal-pebral lobe are more elongate and nearer proportionally to the outermargin. In the thorax the pleurae of the fourth segment areextended into long spines instead of those of the third, as in A.hclena; the pleural lobes and the entire thorax are narrower in pro-portion to the length. In the pygidium there are six rings in theaxis instead of three or four, and two anchylosed pleural segmentspass into the large lateral spines instead of one. Both species haveseven thoracic segments and a finely granulated surface and areassociated in the sahie layers of shale at the ^^lount Bosworthlocality.Formation' axd Locality.—Lower Can:brian : Drift block ofsiliceous shale on south slope of Mount llosworth. on the "Conti-nental Divide ;"' one mile east of Hector, on the Canadian PacificRailwav, British Columbia. Canada. CAMIiKlAX TRlLor.ITES—\\'AI,COTT 23Family OLKxtD.^v SalterORYCTOCARA, new genusDorsal shield small, elliptical. Cephalon semicircular in outline,from one-third to one-fourth the length of the dorsal shield ; genalangles and free cheeks unknown ; cranidium subquadrangular inoutline exclusive of the narrow postero-lateral limbs ; glabella sub-quadrangular in outline, with three lobes and an occipital ring; thelobes are separated by very slightly defined, transverse furrowsterminating in round pits within the lateral margin of the glabella.The facial sutures cut the posterior margin of the head within thegenal angles and pass inward and slightly forward to the base ofthe eye and thence about the palpebral lobe and forward with aslightly outward curvature to the frontal rim. Fixed cheeks broad.Eyes long, with the margin of the palpebral lobe extending acrossthe fixed cheeks as an ocular ridge.Thorax with eleven segments ; pleurae with straight furrows andabrupt, truncated ends.Pygidium large, with central axis divided into several rings bytransverse furrows, all of which extend across the pleural lobes tothe outer margin.Genotype.—Oryctocara gcikici, new species.Observations.—The cranidium of the cephalon of this genus is-much like that of Orycioccphalns Walcott,^ but the thorax andpygidium are unlike. The pleurfe are of the Olcmis Salter type inhaving a straight median furrow, while the pygidium is broad andof the Bathyitriscus- type. (See pi. i, fig. 2, of this paper.)The genus is referred to the order Opisthoparia Beecher and tothe famil}' Olenidse Salter.Only one species from the central portion of the Middle Cambrianis now known.ORYCTOCARA GEIKIEI, new speciesPlate i. Figures 9, 10Dorsal shield small, longitudinally elliptical in outline, moderatelyconvex. Cephalon semicircular in outline, a little less than one-third the length of the dorsal shield ; free cheeks and genal anglesunknown ; a narrow, rounded rim extends across the front of thecranidium and it is probable that it continued along the free cheeksand terminated in a small genal spine. Cranidium subquadrangular ' Walcott, 1886, Bull. U. S. Geol. Survey, No. 30, p. 210. ' Meek, 187.3, Sixth Ann. Rept. U. S. Geol. Survey Territories for 1872, p. 484. 24 S.MITHSOXIAX MISCELLAXHOUS COLLECTIONS VOL. 53in outline exclusive of the postero-lateral limbs ; the latter areelong'ate, subtriangular in outline, and with a narrow, transversefurrow \vithin a rounded rim of medium width. Fixed cheek abouttwo-thirds the w^dth of the glabella and merging posteriorly into thepostero-lateral limb and anteriorly extending to the frontal rim ; there is no defined frontal limb, owing to the glabella extending tothe furrow within the frontal rim ; palpebral lobe narrow, rounded,about one-half the length of the cranidium, and with its outer rimextending across the fixed cheek as a narrow ocular ridge nearlyparallel to the frontal rim of the cranidium ; the palpebral lobeterminates a short distance back of the frontal margin of the gla-bella. Glabella subquadrangular ; slightly narrower at the broadlyrounded front than at the occipital ring, moderately convex ; dividedb}- four faint, transverse furrows into three transverse lobes, ananterior, terminal lobe and an occipital ring ; the faint, transversefurrows terminate on each side in round pits a short distance fromand within the margin ; occipital ring narrow and rounded. Freecheeks unknown. The facial sutures cut the posterior margin oneach side a short distance from the genal angle and extend inwardand slightly forward to the base of the eyes ; curving over the eyesthey extend forward with a slight outward direction, so as to cutthe front margin on a line with the outer edge of the palpebrallobe.Thorax with eleven nearly transverse segments ; the axial lobeis convex and one-half the width of the pleural lobes ; the segmentsof the axial lobe have a deep transverse furrow with the marginselevated ; the doublure on the front margin of each segment curvesdownward, so as to pass beneath the downward slope of the pos-terior half of the next segment in advance of it ; the extremity ofeach segment curves slightly forw-ard. so that the furrow passes(Xit upon the pleura a little in advance of its position at the centerof the axial lobe and in front of the pleural furrow ; the pleura isstraight, nearly flat, and terminating in a blunt, straight marginwithout spine or backward curvature ; the most careful examinationfails to reveal spine or falcate extremity ; the entire side of thethorax appears as though a sharp knife had cut ofif the ends of allthe pleura from the cephalon to the pygidium : the pleural furrowsof each segment originate on a low swelling between the axial andpleural lobes of each segment and extend directly outward to nearlythe end of the segment, where they fade away, so as to leave theend of the segment flat ; the ]ileural furrows are about one-third ofthe width of the segment and arch forward a very little betweenits two extremities. CAMBRIAN TRILOBITES WALCOTT 25Pvgidium large, mocleratel}' convex ; anterior margin slig^htlyarched, so as to join with the posterior segment of the thorax ; ] posterior outline semicircular; axial lobe convex and about two-thirds the length of the pygidium; it is divided into seven transverserings and a terminal section by trans\'«rse furrows ; the pleurallobes slope gently from the axial lobe to the lateral and posteriormargins ; their entire surface is marked by the anchylosed seg-ments, which are similar in appearance to the thoracic segments.excejDt that their backward curvature increases until the ])leurge ofthe posterior segments are nearly parallel to the axis of thepygidium ; the furrows and narrow ridges from the terminal seg-ment of the axis extend backward with a slight inward curvatureall furrows and ridges terminate just within the outer margin in thesame manner as those of the thoracic pleura.Surface with relativel}' large granules on all parts of the dorsalshield.Dimensions.—A dorsal shield 7.25 mm. in length has the fol-lowing dimensions :Cepbalon : mm.Length 1 . 73Length of glabella i • 50Width 2 . 50Width of glabclhi i .coThorax : Length 3-75Width 4-00Width of axial lobe at sixth segment 8.00Width of pleural lobe i . fcoPygidium : Length i • 7?Width at anterior margin 3 • .-0Or.SF,RV.\TioNS.—This is a very rare species, as only one nearlyentire specimen is known : this has the pygidium displaced and thefree cheeks are missing. The combination of characters found inseveral genera is shown (a) in the cranidium, in which the glabellais like that of Oryctoccphalus Walcott ; (b) in the thorax, which isnot unlike that of Olcniis Salter; and (c) in the pygidium, whichsuggests in relative size and form the pygidium of BatliyurisciisJwzi'cUi Walcott.^ Among the associated fossils are Micromitra(Iphidclla) paiuiula (White), Ptychoparia piocJiciisis Walcott,Ptyclwparia cordillercc (Rominger), OryctoccpJiaUis rcynoldsiReed. ZacantJwidcs idaJwensis, new species, and BatliynriscusJimcclii A\'alcott. ' Walcrtt. t886. Bull. U. S. Geo]. Survey, Xo. 30. p. 2ifi. 26 SMITHSONIAN MISCEI.LAN KOUS C(JLLKCTIONS VOL. 53Formation and Locality.—Middle Cambrian : Spence shale ofthe Ute formation, 2,755 feet (839.7 m. ) below the Upper Cambrianin the Liberty Canyon section ; Spence Gulch, a ravine running upinto Danish Flat from Mill Canyon, about 15 miles (9.37 km.) westof Montpelier and 5 miles (3.12 km.) w^est-southwest of Libert\-,Bear Lake County. Idaho, U. S. A.Genus ZACANTHOIDES WalcottZACANTHOIDES IDAHOENSIS, new speciesPi.ATR 3, Figures i-i iDorsal shield large for a species of this genus, moderately convex,longitudinally elliptical in outline. Cephalon semicircular in out-line, one-third the length of the adult dorsal shield ; bordered bv arounded rim of medium width that is continued into strong, sharpgenal spines that extend backward about one-half the length of thethorax ; the posterior border is narrow next to the glabella, fromwhere it widens out to the intergenal spine within the line of thefacial suture ; beyond the facial suture it curves forward and mergesinto the lateral border at the base of the genal spine ; the posteriorintermarginal furrow is sharply defined, and occupies most of thespace between the border and the facial suture ; on the sides andfront of the cephalon the intermarginal furrow is narrow anddistinct. Cranidium with a large glabella, short, small antero-laterallimbs, and elongate, slender postero-lateral limbs that have a short,sharp, slender, intergenal spine extending outward and backwardfrom the outer posterior margin ; fixed cheeks scarcely more thanthe inner sides of the large palpebral lobes and a small, subtriaugulararea in front of the latter ; postero-lateral limbs formed of themarginal border and strong, intermarginal furrows ; a narrowfrontal limb extends across between the glabella and the interborderfurrow ; palpebral lobe about three-fifths the length of the cranidiumand bordered by a narrow, rounded rim that begins, posteriorly,near the median axis opposite the occipital ring, and. curving out-ward, forward, and then inward, terminates at the dorsal furrowbeside the glabella ; it is separated froni the body of the lobe by arounded, shallow furrow. Glabella elongate, subquadrilateral inoutline, moderately convex in front, sides nearly straight, broadlyrounded, and separated from the fixed cheeks and palpebral lobesby a narrow, distinct furrow ; surface marked by a pair of posteriorfurrows that extend obliquely inward, so as to outline two smallsubtriaugular lobes, and two pairs of short, more transverse fur-rows ; the anterior pair is nearly opposite the anterior end of the CAMBRIAN TRILOBITES—WALCOTT 2/palpebral lobe, and the second pair about half way between themand the outer ends of the posterior pair ; on some specimens a fourthpair is faintly defined on the large anterior lobe close to the dorsalfurrow opposite the rounded angle formed by the sides and roundedfront of the glabella. Occipital ring strong, rounded, broadest atthe center, and narrowing gradually toward the ends ; marked by asmall central node near the posterior margin and a rounded, small,depressed tubercle at about one-half the distance between the centralnode and the dorsal furrow ; occipital furrow distinct, narrow, andnearly transverse. Free cheeks large, body gently convex, andrising from the interborder furrow to the base of the elongate, loweye lobe. The facial sutures cut the posterior margin just outsideof the intergenal spine and, curving abruptly inward, extend to theposterior base of the eye lobe ; arching over the latter, they extendforward and slightly outward with a gentle sigmoid curve, so as tocut the outer margin at a distance from the median line of thecranidium equal to the width of the glabella.Thorax with nine segments ; axial lobe convex, a little wider thanthe pleural lobes exclusive of the spinose terminations of thepleurae ; a small elongate node occurs at the center on the posteriorhalf of each segment, except on the fifth, which has a long, slender,backward-extending spine ; on each side, about half way betweenthe center and the dorsal furrow and nearest the anterior margin,there is a rounded, low tubercle, and on the more perfectly preservedspecimens a low, rounded, transverse ridge on each side next to thedorsal furrow ; pleural lobes slightly convex ; each pleura has astrong furrow that is broad at the inner end next to the dorsalfurrow, from whence it narrows gradually to its sharp extremitynear the posterior outer end of the pleura just within the base ofthe terminal spine; a rovmded, elongate, subtriangular tubercleoccupies much of the broad inner end of the furrow ; the frontborder of each pleura is narrow next to the dorsal furrow ; it grad-ually widens toward the outer end and terminates in a strong, long,backward-extending spine ; the narrow posterior border merges intothe base of the terminal spine ; in most specimens the backwardcurvature of the anterior margin of the pleura is so abrupt that anobtuse angle is formed, while in some the margin curves graduallyinto the terminal spine.Pygidium of medium size ; axial lobe convex, narrow, broaderthan the pleural lobes, divided by narrow, transverse furrows intofour rings and a terminal section that, in large specimens, has aslight, transverse furrow that delimits a fifth narrow rins: ; on the 28 S-MITHSONIAX MISCELLANKOUS COLLECTIONS VOL. 53pleural lobes four anchylosed segments are outlined by narrow,deep furrows ; only the two anterior preserve any trace of the pleuralfurrow, and these are very short and obscure ; the pleural segmentsare mainh- made up of the thickened, broad, anterior border andthe strong, backward-extending, rounded spines ; the outer borderis usually obscured until after the fourth spine is passed, and eventhen in some specimens the short fifth and sixth pairs of spinesobscure it ; on other specimens the posterior spines are so slightlydeveloped that the outline of the border ;s preserved.Surface finely granular.Dimensions.—A dorsal shield 38 mm. in length has the follow-ing dimensions : Cephalon : mm.Length 13.0Width at base 30 .Length of eye lobe 7.0Length of glabella 10 . CWidth of glabella, base 6.0Width of glabella, front 6.5Thorax :Length 17.5Width 21.0Axial lobe, anterior segment 8.0Axial lobe, posterior segment 4.5Pleural lobe, anterior segment 6.5Pleural lobe, posterior segment 3.0Pygidium :Length 7.5Width 10. o Axial lobe, anterior segment 4.5Axial lobe, posterior segment 2.5The preceding description is based on adult specimens averaging38 to 45 mm. in length. A large number of young and small speci-mens were found in association with the larger adults, some ofwhich exhibit stages of growth. A specimen 1.9 mm. in length(fig. 5) preserves the cranidium and five segments of the thorax.The glabella widens out toward the front, and the occipital furrowis very faint ; the base of the palpebral lobe is farther out on theposterior margin than in the adult, and its anterior end is at thedorsal furrow and nearer the antero-lateral, rounded angle of theglabella. The pleural lobe has somewhat broader, more direct fur-rows on the pleura, and the spine of the fifth segment is very large ; another important character is the greater extension of the terminalspines of the third thoracic segment—a character unknown in the CAMBRIAN TRILOBITES—WALCOTT 29later stages of growth of this species and a character persistent inAlhertella helena, which occurs over 2,000 feet (609.6 m.) lowerthan the horizon of Zacanthoides spinosus (Rominger) in theCambrian section of the Canadian Rocky Mountains. It also occursin the adult forms of Mesonacis vermontana^ and other trilobites ofthe Olciicllus fauna. A specimen of the entire dorsal shield 3.2 mm.in length has the same widening of the glabella toward the frontas the smaller .specimen, but the base of the palpebral lobes havedrawn in toward the glabella, and the glabella has extended forwardbeyond the anterior extremities of the palpebral lobes ; the thoraxhas only adult characters, except that the third segment appears tohave on one side a stronger terminal spine, and there are but sevensegments ; the spines on the border of the pygidium are short, andbut four can be seen on each side. Specimens 8 mm. in length haveall adult characters in the cephalon and thorax, with the exceptionof the terminal spines of the pygidium, which are shorter and lessclearly defined at the crossing of the border.Observations.—This species occurs abundantly in Idaho. Whencollecting it I thought it to be Zacanthoides typicaUs,' but on directcomparison with that species it was found to differ in having theposterior end of the palpebral lobe nearer the glabella ; the glabellaproportionally narrower in front,, and larger antero-lateral parts ofthe fixed cheek; a broader thoracic axis in proportion to the pleurallobes ; a long median spine on the fifth instead of seventh segment ; a larger pygidium, with broader pleural lobes, more rings on theaxis, and more terminal spines on the pygidium. It is found todiffer from Zacanthoides spinosus (Walcott)'' in having the gla-bella less expanded toward the front; palpebral lobes nearer theglabella at their posterior end ; smaller antero-lateral parts of thefixed cheek ; absence of a strong occipital spine ; in the thorax itdififers in having a long median spine on the central axis at the fifthsegment instead of the seventh, and the axial lobe is proportionallywider; the pygidium differs in having four rings on the axis in-stead of three ; the axial lobe is proportionally longer, and the spineson the pygidium differ in details of shape and number. The threespecies occur at the same relative geological horizon, but are widelyseparated. Z. typicalis occurs at Pioche, Nevada, 350 miles south-southwest of the locality of Z. idahoensis at Spence Gulch, 15 miles 'Walcott, 1891, Tenth Ann. Rept. U. S. Geol. Survey, pi. lxxxvii, fig. la;see also pis. lxxxiv and lxxxv. - Walcott 1886, Bull. U. S. Geol. Survey, No. 30, p. 183. 'Walcott, Mon. U. S. Geol. Survey, vol. viii, 1884, p. 63; and Bull. U. S.Geol. Survey, No. 30, 1886. p. 184. 30 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53west of Montpelier, Idaho; Z. spinosus is from Mount Stephen, inBritish Cokimbia, 685 miles north-northwest of Spence Gulch.Among the associated fossils are Bathyuriscus hoivelli Walcott,Oryctoccphaius reynoldsi Reed, Oryctocara geikiei Walcott, Micro-mitra (Iphidella) pannula (White).Formation and Locality.—Middle Cambrian : Spence shale ofthe Ute formation, 2,755 feet (839.7 m.) below the Upper Cambrianin the Liberty Can_von section ; Spence Gulch, a ravine running upinto Danish Flat from Mill Canyon, about 15 miles (9.37 km.) westof Montpelier, and 5 miles (3.12 km.) west-southwest of Iviberty,Bear Lake County, Idaho, U. S. A.Genus NEOLENUS MatthewNEOLENUS INFLATUS, new speciesPlate; 5, Figures 1-5Dorsal shield large, elongate-elliptical in outline ; axial lobestrongly convex. Cephalon semicircular in outline, with the genalangles produced into sharp spines about one-half the length of thecephalon ; a narrow, rounded rim extends across the front of thecranidium, and, widening a little, runs along the outer margins ofthe free cheeks to the genal angles. The facial sutures cut theposterior margin well within the genal angles with an outwarddirection to the posterior furrow, where they curve inward andforward to the base of the eye lobe ; arching over the eye lobes theycurve outward to about the line of the outer rim of the palpebrallobe, forward to the frontal rim, and then obliquely inward acrossthe rim to the front margin. Cranidium with a prominent, tumidglabella, narrow fixed cheeks, small antero-lateral limbs, and strongpostero-lateral limbs. Glabella large, convex ; the frontal lobe isinflated and, in all but young, small specimens, overhangs the frontalrim ; the sides gradually expand from the occipital ring to thebroadly rounded front, which extends forward to, and lies parallelwith, the furrow within the rounded frontal rim ; the anterior halfof the glabella is taken up by the expanded, anterior lobe and theposterior half is divided into four narrow lobes by shallow furrowsthat extend obliquely inward and slightly backward nearly to themedian line ; in some specimens, especially the young, the furrowsare very faintly defined ; occipital ring separated from the glabellaby a narrow, shallow furrow ; it is broad, moderately convex, andwith a strong, long, sharp, arching spine that extends back over thethorax nearly to the pygidium ; the base of the spine occupies nearlythe entire width of the occipital ring at its center. Fixed cheeks CAMBRIAN" TRILOBITES WALCOTT 3 1 about one-fourth the width of the glabella, gently convex and merg-ing into the anterior and posterior limbs; the posterior limb isabout twice as long as deep below the eye lobe and marked by astrong furrow within the broad, slightly convex posterior border ; palpebral lobe small, 7 mm. long in a cephalon having a length of35 mm. at the eye lobes ; it is bordered by a rounded rim that con-tinues obliquely forward across the fixed cheek and merges into theside of the glabella. Free cheeks large, gently convex ; bordered bya rounded rim that is continued posteriorly into a spine ; posteriormargin rather broad and about one-third the length of the marginbetween the genal angles and the occipital ring; eye lobe small andnot high. The genal spine is situated some distance out from thecentral axis, so that it clears the terminal spines of the thoracicpleurse.Thorax with seven nearly transverse segments ; axial lobe con-vex, with the segments slightly rounded and a small node at thecenter of each ; a low, narrow, transverse ridge occurs on each sidenear the union of the axial and pleural lobes ; pleural lobes a littlewider than the axial lobe and slightly convex ; the pleura is straight,out to the backward curving, terminal spine; the narrow pleuralfurrow originates at the inner end next to the axis and passesobliquely outward, terminating just back of the center of the pleuraat the base of the terminal spine; the latter has a strong base andnarrows rapidly to a sharp point as it extends outward and back-ward a short distance.Pygidium large, moderately convex ; anterior margin nearly trans-verse, posterior outline broadly semi-elliptical ; axial lobe convexand narrowing gradually from the anterior margin to the terminalring at the narrow posterior border; it is divided into ten strong,rounded, transverse rings and a terminal section by ten narrowfurrows ; the terminal section in large specimens has a transversepit on each side of its center that indicates an eleventh ring; a lownode is indicated at the center of each ring, and a low. narrow, trans-verse swelling occurs near the dorsal furrow on each side; in apygidium 8 mm. in length there are nine clearly defined, axial rings,a faint, tenth ring, and an elongate, rounded, terminal section ; pleurallobes slightly convex out to the spinose border, which is flattenedbetween the termination of the pleural grooves and its outer edge;the eight marginal spines on each side are similar to those of thepleural lobes of the thorax with the exception of the posterior ones,which extend directly backward; the space between the axial lobeand the margin is marked by the pleural furrows and the narrow 32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53furrows indicating seven anchylosed segments ; the posterior fur-rows are nearly parallel to the sides of the axial lobe ; the furrowsall terminate on the inner portion of the outer border, the pleuralfurrows with a slight, elongate pit just within the border.Surface with variously arranged, irregular, raised lines or narrow,sharp ridges ; on the glabella they are very slender and arranged ina somewhat concentric manner, although they are broken andirregular ; on the fixed and free cheeks the raised lines are muchstronger, irregular, and more or less anastomosing; on the thoracicsegments the short, irregular raised lines cross the segments of theaxis on each side between the central node and the dorsal furrow,and on the pleurae they extend obliquely across the raised spacesbetween the furrows ; the pygidium has about the same markings atthe thorax except on the flattened border, Avhere the short, elevated,irregular lines extend across the border.Dimensions.—There are two small, nearly entire dorsal shields.One, having a length of 24 mm. exclusive of the posterior spinesof the pygidium, has the following dimensions : Cephalon : mm.Length 9-5Width at posterior margin 11. 5 Thorax ; Length 8.0Width at first segment 14 .Pygidium : Length 7.5Width at anterior margin 10. o A large cranidium, 52 mm. in length, has the following dimen-sions :Glabella : mm.Length 42 . oWidth at posterior margin 88.0Width at occipital furrow 26.0Width just in front of ocular ridge 34.0Palpebral rim, length 7.0A large pygidium, 58 mm. in length, has the following dimen-sions : mm.Width at anterior margin 76.0Axial lobe, length 52 .Axial lobe, width at anterior margin 19.0Axial lobe, width at anterior segment 19.0Axial lobe, width at posterior section 10.Pleural lobe, width at anterior margin 28.5 CAMBRIAN TRILOBITKS—WAIXOTT 33Hypostoina strongly convex, elongate, strongly rounded at thebase, narrowing toward the broadly rounded posterior margin ; border slightly flattened, with a rounded edge; this edge is archedslightly upward on the sides at about the posterior third of thelength of the hypostoma ; a shallow furrow crosses the posterior endof the convex body a short distance in front of the posterior marginand subparallel to it ; the alate lateral limbs are subtriangular in out-line and slightly convex. The surface is marked by fine, irregular,elevated lines that are subparallel to the rim on the margin androughly concentric on the body. An hypostoma 26 mm. in lengthhas a width of 28 mm. at its base, 15 mm. at the arches in the marginor at the posterior third ; convexity at center, 5 mm.The above-described hypostoma is associated with this species,Neolenus superhus, and a less convex hypostoma which is referredto the latter species.Observations.—This large species and the associated Neolenussupcrbus appear to mark the extreme development in size of speciesof Neolenus and its latest occurrence in Cambrian time. Fragmentsof both species are abundant at one locality, and a few entire speci-mens have been found. It is the largest of the Cordilleran Cam-brian trilobites, some of the partially entire specimens indicating alength of 160 mm., width 83 mm.The most nearly related species is Neolenus superhus, from whichNeolenus iniiatus differs in having an inflated glabella, a longerpygidium, and in minor details of the pleurae of the thoracic seg-ments, pygidium, and cephalon. The inflated glabella, long pygi-dium with ten rings and spinose terminations of the thoracic pleurae,separate it from Neolenus serratus (Rominger),^ the type of thegenus. The latter also has a granular surface and falcate termina-tions to the pleurae of the thoracic segments, and the faunal horizonof A^ serratus is 1,900 to 2,125 feet below that of N. inflatus.Formation and Locauty.—Middle Cambrian: 1,895-2,140 feet(605-653.8 m.) below the Upper Cambrian and about 2,000 feet(609.6 m.) above the beds containing Zacantlwides typicalis Walcottand Bathyuriscus hozvelU Walcott, the horizon which is correlatedwith the horizon carrying Neolenus serratus (Rominger) in BritishColumbia," in thin-bedded limestones of the ]\Iarjum formation, inridge on east side of Wheeler Amphitheater, east of AntelopeSprings, House Range, Millard County, Utah, U. S. A. ^ Ogygia serrata Rominger, 1887, Proc. Acad. Nat. Sci. Philadelphia, p. 13.'This British Columbia horizon is given in detail in the Formation andlocality of Burlingia hectori. 34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53NEOLENUS INTERMEDIUS, new speciesPlate 6, Figures 1-7This species, as its name implies, is an intermediate form betweenN. superbus and A^ iniiatus. It differs from both of those species inthe absence of an occipital spine; and in having the sides of theglabella more nearly parallel and with the glabella less expanded infront, and somewhat more pointed or less abruptly rounded. Thepleural lobes of the thorax have a terminal spine on the pleurae ex-tending backward somewhat more abruptly than in either of theother species.The pygidium has five or six rings in the axial lobe and a terminalsegment. A'', iniiatus has ten or eleven rings in the axial lobe andN. superbus has eight rings; N. intermedins has the same numberof terminal spines as N. superbus, but the spines are curved back-ward much more than in the latter species.As far as known, this species does not attain the size of eitherN. superbus or N. iniiatus. The largest cephalon in the collectionhas a length of 35 mm. The proportions of the head and pygidiumare about the same as A^ superbus. The hypostoma referred to thisspecies is proportionally broader and with a larger body propor-tionally than that of A", iniiatus or A'', superbus. In other respectsit is very much like the hypostoma of N. -superbus.Dimensions.—A dorsal shield 74 mm. in length has the followingdimensions : Cephalon : mm.Length 26. 5 Length of glabella 21.0Length of QYQ lobe 4.4Width at posterior margin 44.0Width of glabella at posterior margin 13.5Width of glabella at anterior end 15.0Thorax : Length 27 .Width 41.0Width of axial lobe at first segment 13.0Width of pleural lobe at first segment 13.5Pygidium : Length 20.Width 35 . oWidth of axial lobe at anterior ring 10. o Width of axial lobe at posterior ring 7.5 CAMBRIAX TRILOBITES—WALCOTT 35The surface markings of this species are much like those of N.superhus and N. inflatus, but very much finer. On a cranidium iimm. in length the surface appears smooth, except under a stronglens.Formation and Locality.—Middle Cambrian: 1,895-2,140 feet(605-653.8 m.) below the Upper Cambrian and about 2,000 feet(609.6 m.) above the beds containing Zacaiithoides typicalis Walcottand Bathyuriscus howelli Walcott, the horizon which is correlatedwith the horizon carrying Neolenus serratus (Rominger) in BritishColumbia,^ in thin-bedded limestones of the Marjum formation, inridge on east side of Wheeler Amphitheater, east of AntelopeSprings, House Range, Millard County, Utah, U. S. A.NEOLENUS INTERMEDIUS PUGIO, new varietyPlate 6, Figures 8, 9This variety is founded on four specimens of a pygidium that hasfour rings and a terminal segment in the axial lobe, four marginalspines on each side and three clearly defined anchylosed pleuralsegments marked by oblique pleural furrows. A specimen 11 mm.in length has a width at the front of 36 mm. The axial lobe has awidth of 5 mm. at the first segment and 3 mm. at the terminalsegment.This variety differs from A^. intermedins in having four insteadof five marginal spines on each side of the pygidium, four axialrings instead of five and a shorter terminal section to the axial lobe.A fragment of the outer surface shows it to have been of the sametype as that of A^ superhus.Formation and Locality.—Middle Cambrian: 1,895-2,140 feet(605-653.8 m.) below the Upper Cambrian and about 2,000 feet(609.6 m.) above the beds containing Zacanthoides typicalisWalcott and Bathyuriscus howelli Walcott, the horizon which iscorrelated with the horizon carrying Neolenus serratus (Rominger)in British Columbia,^ in thin-bedded limestones of the Marjumformation, in ridge on east side of Wheeler Amphitheater, east ofAntelope Springs, House Range, Millard County, Utah, U. S. A. ^ This British Columbia horizon is given in detail in the Formation andlocality of Bnrlingia hectori. 36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 55.NEOLENUS SUPERBUS, new speciesPlate 4, Figures 1-5Dorsal shield large, longitudinally elliptical in outline, moderatelyconvex. Cephalon subsemicircular in outline, one-third of thelength of the dorsal shield ; bordered by a strong, slightly convexouter margin that is continued at the genal angles into strong, sharpspines that extend backward and slightly outward to about oppositethe fourth thoracic segment ; the posterior marginal border isnarrow next to the glabella, from where it gradually broadens tothe base of the genal spine ; between the facial suture and thegenal spine the margin arches abruptly forward, so as to throw thebase of the genal spine in front of the line of the posterior margin ; a well defined but narrow furrow separates it from the fixed cheek.Cranidium with a large glabella, narrow antero-lateral limbs, andlarge postero-lateral limbs ; fixed cheeks narrow opposite the palpe-bral lobes ; anteriorly they extend as a narrow, short section to thefront border, and posteriorly merge into the postero-lateral limb,which is nearly as deep from the eye lobe to the posterior marginas from the glabella to its postero-lateral angle ; palpebral lobenarrow, short, and with its outer rim extended diagonally from andacross the fixed cheek to the dorsal furrow, next to the glabella.Glabella elongate, moderately convex; sides nearly straight, andseparated from the fixed cheeks by a narrow, strong furrow, slightlywider where the sides touch the frontal border than at the occipitalfurrow; front broadly rounded and subparallel to the anteriormargin of the cranidium ; surface marked by three pairs of short,oblique furrows that extend inward and slightly backward aboutone-third the distance across the glabella ; a small pit occurs in thedorsal furrow at the antero-lateral angles, and from it a short,obscure furrow extends directly inward for a short distance ; theglabellar furrows are not at all prominent. Occipital ring narrow^ atthe ends, gradually becoming stronger and more convex toward thecenter, where a strong, backward arching spine has its base ; occipitalfurrow nearly transverse, shallow, and terminating in advance of thefurrows of the fixed cheeks. Free cheeks relatively small ; the bodyrises with very little convexity from within the strong outer borderto the base of the short, low eye lobe. The facial sutures cut theposterior margin a short distance wdthin the genal spine, curveslightly outward across the border, and then inward with a gentlesigmoid curve to the base of the eye lobe ; arching over the latter,they extend forward with a slight outward arching across theborder, so as to cut the front margin on a line with the center of theeve lobe. CAMBRIAN TRILOBITES-—WALCOTT 3/Thorax with seven segments ; axial lobe convex, and as wide asthe pleural lobes exclusive of the terminal spines ; a strong, short,sharp spine occurs at the center of each segment, and a narrow,transverse, low, rounded ridge on each side next to the dorsalfurrow ; the pleural lobes are slightly convex ; each pleura has astrong, diagonal furrow that originates near the front margin nextto the dorsal furrow and gradually widens toward the outer end,where it terminates nearly at the center of the pleura and withinthe base of the sharp, terminal spine ; a narrow, rounded ridge occurson each side of the pleural furrow that forms the margins of thepleur?e ; the terminal spines have a broad base and extend obliquelyoutward and slightly backward a short distance.Pygidium large, moderately convex; anterior margin nearlytransverse and posterior outline semicircular ; axial lobe convex, alittle shorter than the entire length ; it is divided into seven ringsand a terminal section by seven nearly transverse, narrow furrows ; a low, narrow median ridge is indicated by the termination of thedeeper portion of each transverse furrow just outside of the medianline ; five anchylosed pleural segments are outlined on the pleurallobes on each side of the axial lobe ; the furrows all terminatewithin the slightly flattened, rounded border, which has five straight,narrow spines extending out from it on each side ; the anteriorsegment of the pygidium is so much like the segments of the thoraxthat it is difiicult to distinguish it from the thorax.Hypostoma similar to that oi Neolenus inflatus, except that itsbody is less convex, and small specimens show an elongate tubercleon each side just back- of the line separating the convex body fromits posterior, Tess convex, and narrower portion.Surface with variously arranged, irregular, short, very fine,raised lines or minute ridges ; on the glabella they are arrangedin a concentric manner, although very irregular and interrupted bynumerous breaks in continuity and strength ; on the cheeks the linesare somewhat coarser ; on the thorax and pygidium the lines areexceedingly fine and inconspicuous ; where seen they have about thesame arrangement as those of the surface of Neolcnns inflatus.Dimensions.—A dorsal shield 65 mm. in length has the followingdimensions : Cephalon : mm.Length 23 . 00Length of glabella 17.00Length of eye lobe 2 . 75Width at base 38.00Width of glabella at posterior margin 12.00Width of glabella at anterior end 13.50 38 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53Thorax : mm.Length " 24 . ooWidth 30.00Width of axial lobe at first segment 10.00Width of pleural lobe at first segment 10.00Pygidium : Length 18.00Width 26 . 00Width of axial lobe at anterior ring 9.00Width of axial lobe at posterior ring 6.50Hypostonia : Length 29 . 00Length of body 26 . 00Width 18.00Width at base 23 . 00Width at junction with head 33.00Greatest width of body 19.00Observations.—This species attains a large size. A cephalon andsix thoracic segments has a length of 73 mm., a width of thorax of70 mm. ; with the seventh segment and the pygidium, exclusive ofspines, the entire shield would have had a length of 107 mm.Fragments occur that indicate even a larger size.Neolenus superhiis and the associated Neolenus inftatus havemany characters common to each ; both attain a large size, both havesmall eyes, subquadrilateral glabellas, spinose genal angles, seventhoracic segments, spinose terminations to pleural segments andborder of pygidium, occipital and thoracic median spines, linedsurfaces, and resemble each other in minor details. The two speciesdiffer in the glabella of N. siipcrhns being slightly convex withnearl}^ parallel sides, instead of being inflated and expanded towardthe front. The pygidium of A^ superbus has seven axial rings andfive spines on the border ; that of N. iniiatus has nine rings and eightspines. Neolemis serratns (Rominger)^ has a broader dorsal shield,falcate terminations to the pleural segments, four rings on the axisof the pygidium, a subquadrangular glabella and genal spines thatare formed by the union of the outer border and posterior border,instead of being a continuation of the outer border, as in A^. superbusand A^. infJatns. The surface of N. serratns is granular and notraised lines, as in N. superbus.Formation and Locality.—Middle Cambrian: 1,895-2,140 feet(605-653.8 m.) below the L^pper Cambrian and about 2,000 feet(609.6 m.) above the beds containing Zacanthoides typicalis Walcottand Bathynriscus hozveUi Walcott, the horizon which is correlated * Ogygia serrata Rominger, 1887, Proc. Acad. Nat. Sci. Philadelphia, p. 13. CAMBRIAN TRILOBITES—WAIXOTT 39 with the horizon carrying Neoleniis serratus (Rominger) in BritishCokimbia/ in thin-bedded limestones of the Marjuni formation, inridge on east side of Wheeler Amphitheater, east of AntelopeSprings, House Range, Millard County, Utah, U. S. A.Genus BATHYURISCUS. MeekBATHYURISCUS ORNATUS, new speciesPlate i, Figures 1-3Dorsal shield small for the genus, longitudinally oval in outline, •moderately convex. Cephalon semicircular in outline; a little lessthan one-third the length of the dorsal shield ; bordered by a narrow,rounded margin that passes, at the rounded genal angle, into thevery narrow posterior border ; the interborder furrow is sharplydefined all about the outer border, and within the posterior borderit is a straight, rather broad, shallow furrow. Cranidium large,with very small antero-lateral and large postero-lateral limbs ; theformer are nearly as long as broad and separated from the fixedcheeks by the strong ocular ridges ; the postero-lateral limbs andfixed cheeks merge into each other so as to form subtriangular areas,with the narrow palpebral lobes on their front outer margins forabout one-third of their length ; the palpebral lobes are small, aboutone-fourth to one-fifth the length of the cranidium and borderedby a strong, narrow, rounded rim that extends across the fixedcheeks to the dorsal furrow, beside the glabella.Glabella large, a little wider in front than at the occipital furrowand with slightly diverging sides ; front broadly rounded ; surfacemarked by four pairs of furrows, the posterior of which extendsobliquely inward across the posterior portion nearly to the center,so as to separate a small subtriangular lobe on each side ; the threeanterior pairs of furrows are short, close to the dorsal furrow, andabout equal distances from each other. Occipital ring very narrowat its ends, from where it broadens rapidly to its full width ; a short,oblique furrow occurs on each side that is subparallel to the posteriorpair of glabellar furrows, that serve to separate the central portionof the occipital ring from its end sections ; occipital furrow narrow,distinct, transverse, and terminating in advance of the posteriorintermarginal furrows of the fixed cheeks. Free cheeks small,elongate, and with rounded posterior angles ; eye lobes small. Thefacial sutures cut the posterior margin just within the genal angleand extend obliquely forward and inward with a slight sigmoid ^ This British CoUimbia horizon is given in detail in the Formation andlocality of Burlingia Jicctcri. 40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53curvature to the base of the eye lobes ; curving over and around theeye lobes, they pass forward and a little outward to the front margin ; the distance between the eye lobes and margin is about the lengthof the eye lobe.Thorax with eight segments; axial lobe moderately convex, aboutas wide as the pleural lobes in partially conipressed specimens ; onthe outer side of each segment a rounded, transverse node or ridgeis separated from the main body of the segment by a slightly obliquefurrow transverse to the segment ; the furrows are similar to thosecrossing the occipital ring; pleural lobes slightly convex and withthe extremities of the pleurae bending slightly downward ; eachpleura has very narrow, raised margins next to the axial lobe thatgradually broaden and slope inward out to the slight geniculation,v^rhere they form an elongated node with straight outer edge, which,touching against the nodes upon the adjoining pleura, forms anelongated, rounded node transversely divided by the line separatingthe pleurae; an elongated, tapering, rounded node, with its baseat the dorsal furrow, occupies the inner half of the pleura ; a narrowgroove on each side of the node united to form a shallow pleuralfurrow that terminates within the somewhat abruptly pointed outerextremity of each pleura.Pygidium of medium size, about one-fourth the length of thedorsal shield ; anterior margin nearly transverse, except where itbends backw^ard near the outer ends ; posterior outline semicircular ; axial lobe moderately convex and tapering gradually toward theposterior section ; it is divided by four transverse furrows into fourrings and a terminal segment ; four anch3^1osed pleural segments areoutlined on the pleural lobes on each side of the axial lobe by fur-rows that progressively curve backward from the first to the pos-terior adjoining the terminal segment; the furrows all terminatewithin the narrow, slightly flattened border.Surface finely granulose.Dimensions.—A dorsal shield 13.5 mm. in length has the follow-ing dimensions : Cephalon : mm.Length 50Length of eye lobe 0.9Width at posterior margin 9.0Width of glabella at posterior margin 2.4Thorax : Length 5-5Width 8.5Width of axial lobe at first segment 2.3Width of axial lobe at eighth segment 1. 9 CAMBRIAN TRILOBITES—WALCOTT 4IPygidium : mm.Length 2.9Width at union with thorax 6.0Observations.—This species is rather rare at Mount Stephen,although 18 specimens were found in the collections of 1907. Thelargest specimen of the dorsal shield has a length of 18 mm. Thestrong triangular nodes on the pleural portion of the segments nextto the axial lobe and the nodes at the geniculation, combined withthe clearly defined furrows about them, give the thorax a verystriking ornamental effect that leads to giving the specific nameoniatus. This type of thoracic segment serves to distinguish thespecies from all other species of the genus Bathyitriscns. Theassociated B. rotundatus (Rominger)^ has quite a dift'erent pleuralsegment, larger pygidium in proportion to the length of the dorsalshield, and nine thoracic segments instead of the eight, as in B.oniatiis.Another associated species, Bathyurisctts occidentalis (Matthew)."has nine segments with an open pleural furrow, relatively smallerpygidium, and larger free cheek.FoR.MATiON AND LOCALITY.—Middle Cambrian: Ogygopsis shaleof the Stephen formation, 2,400 feet (731.5 m.) above the LowerCambrian and 2,600 feet (792.5 m.) below the Upper Cambrian;northwest slope of Mount Stephen, 3,000 feet (914.4 m.) above theKicking Horse River, above Field, on the Canadian Pacific Railway,British Columbia, Canada. ^ Lliiiboliimis rotundatus Roniinger, 1887, Proc. Acad. Nat. Sci. Philadelphia,p. t6. " Dolichometopus occidentalis Matthew, 1899. Trans. Roy. Soc. Canada for1899, 2d ser., vol. V, sec. 4, No. 2, p. 49. 42 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 DESCRIPTION OF PLATE i PageBathynriscus oniatiis, new species 39Fig. I. A broken specimen, showing character of cephalon and thorax.U. S. National Museum, Catalogue No. 53420.2. A small nearly entire dorsal shield, with the exception of thefree cheeks. U. S. National Museum, Catalogue No. 53421.3. Two segments of the thorax enlarged to show the details of theaxial and pleural lobes. U. S. National Museum, CatalogueNo. 53423.The specimens represented by figures 1-3 are from the Mid-dle Cambrian Ogygopsis shale of the Stephen formation,2,400 feet (731.5 m.) above the Lower Cambrian, on the north-west slope of Mt. Stephen, near Field, British Columbia.Albertella bosivorthi, new genus and new species 22Fig. 4. Cephalon, showing character of the palpebral lobes. Comparethis with the cephalon of Albertella hclena on pi. 2, figs, i, 4,and 5. U. S. National Museum, Catalogue No. 53413.5. A specimen showing the character of the thorax and pygidium.U. S. National Museum, Catalogue No. 53416.6. Pygidium, which compare with pygidium of A. hclena pi. 2, fig.2. U. S. National Museum, Catalogue No. 53415.7. Inner side of a very small pj^gidium. U. S. National Museum,Catalogvie No. 53406.The specimens represented by figures 4-7 are from a driftblock of Lower Cambrian shales found on the slopes of Mt.Bosworth, just north of the Canadian Pacific Railway, onemile (0.62 km.) east of Hector, British Columbia.Buxlingia h'ectori, new genus and new species 15Fig. 8. A nearly entire specimen greatly enlarged. U. S. NationalMuseum, Catalogue No. 53418.The specimen represented by figure 8 is from the MiddleCambrian Ogygopsis shale of the Stephen formation, 2,400feet (731.5 m.) above the Lower Cambrian, on the northwestslope of Mt. Stephen, near Field, British Columbia.Oryctocara geikici. new genus and new species 23Fig. 9. A nearly entire dorsal shield with the exception of the freecheeks. U. S. National ]\Iu?eum, Catalogue No. 53426.10. Greatly enlarged matrix of a small pygidium. U. S. NationalMuseum, Catalogue No. 53427.The specimens represented by figures 9-10 are from theSpence shale of the Ute formation, near the base of the Mid-dle Cambrian, in a ravine running up into Danish Flat fromMill Canyon, about 15 miles (9.37 km.) west of Montpelier,and 5 miles (3.12 km.) west-southwest of Liberty, Bear LakeCountv, Idaho. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53, PL. 1 CAMBRIAN TRILOBITES 44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 DESCRIPTION OF PLATE 2 PageAlbertella hclcna, new genus and new species 19Fig. I. A nearly entire dorsal shield. U. S. National Museum, Cata-logue No. 53410.2. A pygidium retaining much of its natural form. The outer testis exfoliated about the margins. U. S. National Museum,Catalogue No. 53411.3. A very small dorsal shield. U. S. National Museum, CatalogueNo. 53409.4. A large, broken dorsal shield. U. S. National Museum, Cata-logue No. 53407-5. A large cranidium. U. S. National JMuseum, Catalogue No. ) 53408.6. Hypostoma associated with this species. U. S. National Mu-seum, Catalogue No. 53414.7. A pygidium which compare with the pygidium of A. bosivorthion pi. I, fig. 6. U. S. National Museum, Catalogue No. 53403.8. A broken dorsal shield, broadened by compression. U. S. Na-tional Museum, Catalogue No. 53402.9. A small dorsal shield. U. S. National Museum, Catalogue No.53404-The specimens represented by figures 1-5 are from LowerCambrian shales on Gordon Creek, Ovando Quadrangle, PowellCounty, Montana, and those represented by figures 6-9 arefrom a drift block of Lower Cambrian shales found on theslopes of Mt. Bosworth, just north of the Canadian PacificRailway, one mile (0.62 km.) east of Hector, British Columbia. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53, PL. 2 CAMBRIAN TRILOBITES 46 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.53 DESCRIPTION OF PLATE 3 PageZacanthoidcs idalwcnsis 26Fig. I. A large dorsal shield compressed in the shale. U. S. NationalMuseum, Catalogue No. 53434.2. A small dorsal shield with seven thoracic segments and threespines on each side of pygidium. U. S. National Museum,Catalogue No. 53437-3. Small dorsal shield with adult characters. U. S. National Mu-seum, Catalogue No. 53435.4. Small dorsal shield with adult characters. U. S. National Mu-seum, Catalogue No. 53436.5. Dorsal shield of a very young individual with a strong spineon the axial lobe of the fifth segment. U. S. National Mu-seum, Catalogue No. 53440.6. Large free cheek. U. S. National Museum, Catalogue No.53432.Figs. 7, 8, and 11. Pygidia illustrating variations in spinose border.U. S. National Museum, Catalogue Nos. 53429, 53430, and53431-Fig. 9. Fragment of a large adult dorsal shield showing interocularspine, free cheek in position, and the lateral position of thegenal spine on the free cheek. U. S. National Museum, Cata-logue No. 53433-10. Fifth thoracic segment with median spine. U. S. National Mu-seum, Catalogue No. 53438.The specimens represented by figures i-io are from theSpencc shale of the Ute formation, near the base of theMiddle Cambrian, in a ravine running up into Danish Flatfrom Mill Canyon, about 15 miles (9.37 km.) west of Mont-pelier, and 5 miles (3.12 km.) west-southwest of Liberty, BearLake County, Idaho. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53, PL. 3 CAMBRIAN TRILOBITES 48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 DESCRIPTION OF PLATE 4 PageNcoleniis supcrbus, new species 36Fig. I. A nearly entire dorsal shield with the occipital spine broken off.U. S. National Museum, Catalogue No. 53383.Figs. 2 and 2a. Hypostoma associated with this species. U. S. NationalMuseum, Catalogue No. 53381.Fig. 3. Large compressed cranidium. U. S. National Museum, Cata-logue No. 53384.4. Small convex cranidium. U. S. National Museum, CatalogueNo. 53382.5. Portion of a large dorsal shield with well preserved outline ofthe cephalon. U. S. National Museum, Catalogue No. 53380.The specimens represented by figures 1-5 are all from thin-bedded Middle Cambrian limestones of the Marjum forma-tion, 2,140 feet (652.3 m.) above the top of the Lower Cam-brian, in ridge on east side of Wheeler Amphitheater, east ofAntelope Springs, House Range. Millard County, Utah. Smithsoman miscellaneous collections VOL. 5?1, PL. 4 CAMBRIAN TRILOBITES 50 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 DESCRIPTION OF PLATE 5 PageNeolcnus iiiflatus. new species 30Fig. I. A small nearly entire dorsal shield with the exception of thefree cheeks. U. S. National Museum, Catalogue No. 53390-Figs. 2 and 20. A large cranidium. U. S. National Museum, CatalogueNo. 53389-Fig. 3. A characteristic pygidium. U. S. National Museum, CatalogueNo. 53388.Figs. 4 and 4a. Associated hypostoma. U. S. National Museum, Cata-logue No. 53386.5. Enlargement of the exterior ornamentation of the surface ofthe fixed cheek back of the palpebral lobe. U. S. NationalMuseum, Catalogue No. 53387.The specimen represented by figure i is from thin-beddedMiddle Cambrian limestones 2,300 feet (701 m.) above theLower Cambrian ; and the specimens represented by figures2-5 are from thin-bedded Middle Cambrian limestones 2,140feet (652.3 m.) above the top of the Lower Cambrian, both inthe Marjuni formation, in the ridge on east side of WheelerAmphitheater, east of Antelope Springs, Millard County,Utah. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53, PL. 5 CAMBRIAN TRILOBITES 52 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 DESCRIPTION OF PLATE 6 PageNeolenus intcnncdius, new species 34Fig. I. Cranidium and thorax; natural size. U. S. National Museum,Catalogue No. 53397.2. Cranidium; natural size. U. S. National Museum, CatalogueNo. 53394.3. A pygidium with five marginal spines. Compare this pygidiumwith that of Neolenus supcrbus on pi. 4, fig. i. U. S. Na-tional Museum, Catalogue No. 53398.4. A pygidium with six marginal spines that is doubtfully referredto this species. U. S. National Museum, Catalogue No. 53392.5. A small convex cranidium doubtfully referred to this species.U. S. National Museum, Catalogue No. 53395-6. A small cranidium with a strong occipital node. U. S. NationalMuseum. Catalogue No. 53396.7. Hypostoma associated with this species. U. S. National Mu-seum, Catalogue No. 53393-The specimen represented by figure 6 is from thin-beddedMiddle Cambrian liijiestones 2,075 feet (632.5 m.) above theLower Cambrian ; that represented by figure S is from thin-bedded Middle Cambrian limestones 2,140 feet (652.3 m.)above the Lower Cambrian ; and those represented by figures1-4, and 7 are from thin-bedded Middle Cambrian limestones2,300 feet (701m.) above the Lower Cambrian; all in theMarjum formation, in ridge on east side of Wheeler Amphi-theater, east of Antelope Springs, House Range, MillardCounty, Utah.Neolenus iittcniicdiiis piigio, new variety 35Fig. 8. Fragment of a large dorsal shield with missing parts restored inoutline. U. S. National Museum, Catalogue No. 53400.9. A broken pygidium. U. S. National Museum, Catalogue No.53401.The specimens represented by figures 8 and 9 are from thin-bedded Middle Cambrian limestones of the Marjum forma-tion, 2.300 feet (701 m.) above the Lower Cambrian, in ridgeon east side of Wheeler Amphitheater, east of AntelopeSprings, House Range, Millard County, Utah. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 63 PL. CAMBRIAN TRILOBITES CORRECTIONS TO BE INSERTED IN SMITHSONIAN MIS-CELLANEOUS COLLECTIONS, VOLUME LIIL Note.—This slip is so arranged that it may be torn apart and pasted inpapers Nos. i, 2, and 3. CAMBRLAN OEOLOCY AND PALKONTOLOCY. WAIXOTT.No. I.—NoMF;Ncr..ATt'Riv oi' SoMiv Cambrian CoRnri.i.TvRAN 1''orm ations.Page 2. Tiie Mount Wliyte formation which is place (605-653.8 m.) should read (577.6-652.3 m.) CAMBRIAN GEOLOGY AND PALEONTOL(K'.Y. \VALC< )TT.No. 3.—Cambrian Brachiohoda : Descriptions oi- Nkw Gknkra anh SrivCii's.Page 57. 32d line, "base of tlie Wolsey shale" should read "top of thequartzitic sandstones." " 101. 18th line, strike out "Wolsey." The shale mentioned on these pagesis not the equivalent of the Wolsey shale.