CAMBRIAN BRACHIOPODA WITH DESCRIPTIONS OF NEWGENERA AND SPECIES.
By Charles D. Walcott,Honorary Curator, Division of Stratigraphic Paleontology.
The following genera and subgenera are referred to in this paper,either in describing them or in referring new species to them: *Protremata: BillingseUa; BllUng-selhi {(Hus/a); Nisa-sia; JVisusia{Jamesella); StropJioniena {EostropKomena); Ovtlih {Plectorthls)
;
Orthis (Orusia); OrtJiis {Finkelnhurgia); Protorthh; Protorthis{Loperia); Syntrophia; Polytcochia; Swantonia.Neotremata: Oholella; Acrotreta; Acrothyra; Acrothele.Atremata: Tphidella,' Kutorgina; Ru>^tdl(i; P/ceUonius; Cartlcea;Quehecia; Elhmia; ScJmchertma; Oholas; Oholnx {LlngnleUa); Oho-lus {Lingtdepis); Oholm ( Westonia).This is the sixth paper resulting from the pi-eliminary studies forthe monograph on the Cambrian Brachiopoda. These notes/' likethose that have preceded, are published in the hope that they may beof service to students prior to the appearance of the monograph.Genus BILLINGSELLA Hall and Clarke.1857. Orthis Billings, Report (leologit-al Survey of Canada, \k 297.1860. Orfhlx SituMARD, Trans. 8t. Louis Aead. Sci., I, p. (527.
?Note on the genus Lingulepis, Anier. Jour. Sci., 4th ser., Ill, 1897, pp. 404, 405.Cambrian Brachiopoda: Genera Iphidea and Yorkia, with descriptions of new-species of each, and of the genus Acrothele, Proc. U. S. Nat. Mus., XIX, 1897, pp.707-718.Note on the brachiopod fauna of the cpiartzitic pebbles of the Carboniferous con-glomerates of the Narragansett Basin, Rhode Island, Amer. Jour. Sci., 4th ser., VI,1898, pp. 327, 328.Cambrian Brachiopoda: Obolus and Lingulella, with descriptions of new species,Proc. U. S. Nat. Mus., XXI, 1898, pp. .385-420.Cambrian Brachiopoda: Obolella, subgenus Glyptias; Bicia; Obolus, subgenusWestonia; with descriptions of new species, Proc. U. S. Nat. Mus., XXIII, 1901, pp.669-695.Cam/)rian Brachiopoda: Acrotreta; Linnarssonella; Obolus; with descriptions ofnew species, Proc. U. S. Nat. Mus., XXV, 1902, pp. 577-612.Proceedings U. S. National Museum, Vol. XXVIII?No. 1395. 227
228 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
18fil. Otililfiiufc BiLLiNcis, (Jeology of Vernioiit, II, p. 94i), figs. 3r)0-;!5L*.1S()1. Ov7///'.s/;/a Bn;i,iN(is, Paleozoic Fo^^nil^, I, p. 10, figs. II, 12.1862. (>/7/(/,s'//wf Hillings, Paleozoic Fossils, I, p. ^'M, lig. 115.1863. OrthlK Hall, 16t,h Kept. N. Y. State Cab. Nat. Hist., p. 134, pi. vi, figs. 23-27.1863. Orthisina Billings, Geology of Canada, p. 284, fig. 289.1867. Orthisina Hall, Trans. Albany Institute, V, p. 113.1868. Orthis Hartt, Dawson's Acadian Geology, Second Edition, p. 644,fig. 233.1882. Orthis Whitfield, Geology of Wisconsin, IV, p. 170, pi. i, figs. 4, 5.1883. Orthis {Orthisina f) Hall, Report of State Geologist, N. Y., pi. xxxvii,figs. 16-19.1884. Orthinina Whitfield, Bull. Am. Mus. Nat. Hist., I, p. 144, pi. xiv, fig. 6.1884. Orthis Walcott, Bull. No. 10, U. S. Geol. Survey, p. 17, pi. i, figs. 1, la-d.?1884. Orthis Walcott, Mongr. U. S. Geol. Survey, VIII, p. 22, pi. ix, figs. 8, 8a.1886. Orthisina Walcott, Bull. No. 30, U. S. Geol. Survey, pp. 120-122, pi. vii,figs. 5-7.1886. Orthis Matthew, Trans. Roy. Soc. of Canada, Sec. IV, p. 43, pi. v, figs.20a-c; (?) p. 42, pi. v, figs. 18a-c.1892. BiUingsella Hall and Clarke, Pal. New York, VIII, Pt. 1, p. 230.1896. Orthis {BiUingsella) Sardeson, Bull. Minnesota Acad. Nat. Sci., IV,p. 96.1897. Eillingsella Schuchert, Bull. U. S. Geol. Survey, No. 87, p. 158.Diagnosis.?Shell subqimdrate or subsemicircular in outline. Con-tour unequally biconvex or plano-convex. Shell punctate. (?) Surfacestriate or plicate. Ventral valve with the greatest convexity; cardinalarea moderately high, slightly inclined outward; delthyrium coveredby a convex plate which in the type species B. coloradoerisis has aminute perforation near the apex; teeth well developed, with dentalplates extending to the bottom of the umbonal cavity and forming thesides of a small area opposite the delthyrium, where the pedicle mus-cle was probably attached. In the dorsal valve the cardinal area isstrongly inclined, but less than 90? to the plane of the valve. Thedelthyrium is partially covered by a convex chilidium, or it may bealtogether absent. Cardinal process single.Type.? OrtJds coloradoensis Shumard.OhseTvations.?Messrs. Hall and Clarke founded the genus on Orthispepina Hall, which is a synonym of Ortliis coloradoenslx Shumard.The material from the limestones of Texas in the collections of theSurvey show the form of the teeth in the ventral valve, also the delti-dium and the minute perforation near its apex. Messrs. Hall andClarke state in their diagnosis that "in rare instances [it] may beminutely perforated at the apex," but do not name the species inwhich the perforation occurs or where the specimens showing it areto be found. All the species known to me are biconvex or plano-convex; none are concavo-convex as defined by Messrs. Hall andClarke.The genus is essentially orthoid, but it differs in the presence of thearched deltidium and its general aspect.
NO. 1395. CAMBRIAN BRACHIORODA?WALCOTT. 229The species may be o-r<>uped on surface characters into four sectionsas follows:1. Costate:B. f appalachia.B. coloradoensis.B. dice.B. exporreda.B. hicksi.B. lindstromi.B. major.B. obscura.B. orientalis.B. pumpeUyi.B. 1'ichtJiofeni.B. romingeri.B. striata.2. Smooth costate:B. plicatella.3. Smooth striate:B. highlandi'usis.4. Smooth:B. f anomala.B. harlanensis.B. saffordi.B. salemenm.B. ivhitfieldi.Of the species referred to the genus, BiJl/7igsella exporreda is onethat departs from the t3^pical species in the absence of a convex delti-dium; whether this is owing to the absence of a deltidium originallyor to its accidental removal from the specimens studied, is undecided.The species referred to Bllliiujsella are:
Name. Cambrian. Ord.
i anomala, new species? appai:^^hia, new species ,cn'.jradoensis Shumarddice, new speciesexpm-rectaexporrecta var. rugosicostata, new variety .harlanensis, ;iew specieshicksi (Salter) Davidsonhighlandensis Walcottlindstromi Linnarsson ,major, new speciesobscura, new species ,orientalis Whitfieldplicatella, new speciespumpellyi, new speciesrichthofeni, new speciesromingeri Barr. (Sp.)saffordi, new speciessaleme7isis Walcottstriata, new specieswMtfieldi WalcottOtusia, new subgenus of Billingsella.( Otusia) sandbergi Winchell
230 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.xxviii.BILLINGSELLA ? ANOMALA, new species.Shell sul)([uadrilateral, with the dorsal valve transvei'se. On theventral valve the cardinal line slopes toward the beak at an angle offrom 15? to 20?, while in the dorsal valve it is nearly straight. Thegreatest width of the valves is about the middle of the shell. Owingto compression and consequent distortion there is considerable varia-tion in the relative proportions of length and breadth. The cardinalangle is acute, in some instances extending out some distance bej^ondthe widest portion of the shell, resembling in this respect the cardinalangles of some of the Stromphomenida?. All of the specimens are socompressed in the shale that little is preserved of their natural con-vexit3\ A low, broad, mesial sinus occurs on the dorsal valve, andthere is a slight flattening of the anterior central portion of the ven-tral valve.The surface is marked by tine, radiating stri;e that are increased innumber toward the front by the addition of interstitial stria?, givinga fasciculate appearance to the surface. The radiating striie arecrossed by concentric lines of growth and tine striw. The surface asdescribed occurs in one specimen, all other specimens being nearlysmooth. This, however, may arise from maceration and flatteningout of the surface characters by compression. The interior of theshell appears to have been covered b}" minute punctffi.The largest specimen of the collection has a transverse diameter of14 mm. " The average size of the ventral valve is about 8 mm. inheight by 8 mm. in width.Cardinal area about one-fifth the height of the shell. It is markedby transverse stri* of growth that cross it parallel to its base.Delthyrium rather broad. No traces of the deltidium have beenobserved. Cardinal area of the dorsal valve short. It is dividedmidway by a strong delthyrium. Nothing is known of the interiorcharacters except the presence of short crura in the dorsal valve.Observations.?This shell occurs quite abundantly in the' very fine,buff-colored, argillaceous shales of the Coosa Valley Cambrian section.There is doubt as to its surface characters, as only one specimen foundin the same beds has radiating stride. All others appear to be nearlysmooth. Its strongest character is the extension of the cardinal angle.Owing to the imperfection of the material the generic reference isdoubtful.Formation and locality.-?Middle Cambrian, Coosa Valley shales.Cowan Creek section. Edwards farm, near Craigs Mountain, Cherokee County, Alabama.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 231BILLINGSELLA? APPALACHIA, new species.The outline of the dorsal valve is rounded subquadi'ate. The heightand width of the venti'al valve are about the same. Dorsal valveslightly transverse.The surface is marked by round, very fine, radiating costse, andlines of growth, with very fine interstitial concentric stri^.The average size of the ventral valve is about 10 mm. in heightwith an equal width. The largest shell observed was a ventral valvewith a width of 14 mm.Cardinal area of the ventral valve rather low. It is divided midwayby a rather strong delthyrium.Ohservatimis.?This shell in form and size is much like that of Bfanomala. It differs in strongly marked surface characters. All thespecimens are flattened in the shale by compression, and nothing isknown of the interior characters.Formation and locality.?Upper Cambrian. Rogersville shales.Four miles northeast of Rogersville, on roadside just east of Harlan'sKnob, Tennessee.BILLINGESLLA COLORADOENSIS Shumard.OrtMs coloradoensis Shumard, Trans. St. Louis Acad. Sci., I, 1860, p. 627.Orthis pepina Hall, 16th Kept. N. Y. State Cab. Nat. Hist., 1863, p. 134, pi. vi,figs. 23-27.Orthis pepina Hall, Trans. Albany Institute, V, 1867, j). 113.Orthis pepina Whitfield, Geol. Wisconsin, IV, 1882, p. 170, pi. i, figs. 4, 5.Orthis f (Orthisinaf) pepina Hall, 2d Ann. Rpt. N. Y. State Geologist, 1883,pi. XXXVII, figs. 16-19.BiUingsella pepina Hall and Clarke, Pal. New York, VIII, 1892, Pt. 1, pi.VII, figs. 18-19; pi. viiA, figs. 7-9.Orthis (BiUingsella) pepina Sardesox, Bull. Minnesota Acad. Nat. Sci., IV,1896, p. 96.BiUingsella coloradoensis Schuchert, Bull. U. S. Geol. Sur., No. 87, 1897, p. 158.BiUingsella coloradoensis Walcott, Mongr. XXXII, U. S. Geol. Survey, Pt. 2,1899, p. 450, pi. Lxi, tigs. 1, 1 a-d.Shell usually transverse, but in many examples the ventral valve islonger than wide. The general outline is irregularly subquadrate tosubsemicircular. On the ventral valve the hinge line slopes towardthe beak at a low angle, while in the dorsal valve it is nearly straight.In some individuals the greatest width is at the hinge line. In othersit is at about the middle. There is considerable variation in the rela-tive proportions of length and breadth.The ventral valve is slightly more convex than the dorsal. Thedegree of convexity of the two valves varies considerably in specimensfrom different localities. Some of the ventral valves from the Hudsonbeds at Franconia, Minnesota and the young shells from Trempealeau,Wisconsin are strongly convex.
232 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.A low, broad, inosiul sinus oecui's on nearl}" all specimens of thedorsal valve, being strongest in the young shells, and occasionally ashallow sinus is clearly defined on the ventral valve. It is quite rareto tind a well-marked median fold on the ventral valve.The surface is marked by sharply rounded, line, radiating costse,crossed by tine, concentric lines of growth, and very fine, slightlyundulating concentric strite. The size and sharpness of the radiatingcostaj vary greatly in specimens from the same bed at the typicallocality in Texas. Shells occur with strong, rounded costse, and notraces of fine, elevated lines between, while others show from one tofour or more lines that start at varying distances from the beak. Theimbricating lines of growth give a concentrically ridged aspect tosome shells, while others are nearly smooth from beak to frontalmargin. The increase in the num])er of costs? is by interpolation, notby bifurcation.There is considerable variation in the size of the shell. The largestspecimens from Texas have a transverse diameter of 19 mm., with aheighthof 14 mm. for the dorsal valve, and about 18 mm. for the ven-tral valve. Specimens of the ventral valve from the YellowstoneNational Park have a height of 14 mm. with a width of 15 mm.Cardinal area of ventral valve moderately high. It is marked bytransverse stride of growth that cross it parallel to its base and archover the convex deltidium. The plane of the area extends backwardat an angle of about 10*^ to the plane of the margin of the shell. Thedelthyrium is strong and covered by a convex deltidium, the frontmargin of which arches back about one-fifth the length of the del-th3a"ium; the deltidium is marked by concentric striae of growth andfine radiating lines and a minute perforation near its apex. The cardi-nal area of the dorsal valve is short as comj)ared with the ventralvalve. It extends backward at an angle of about 45? to the plane ofthe margin of the valve. It is divided midway by a strong delthyrium,which is covered about half its distance by a convex chilidium.In the interior of the ventral valve the hinge teeth appear to be sup-ported by dental plates that extend down to the bottom of the valveand bound the tripartite umbonal space opposite the delthyrium, intowhich the vascular sinuses extend on each side of the diductor muscleimpressions, or their path of advance. The traces of the vascular S3^s-tem are confined to the main vascular trunks, which extend forwardnearly to the front margin, where in some examples they are bifur-cated. The inner branch extends in toward the median line, disap-pearing in the numerous radiating depressions near the margin. Thelateral branches appear to connect with the peripheral canal, that archesabout the space, probably occupied by the ovarian areas, betweenitself and the main vascular trunks. The spaces for the attachment ofthe muscles between the main vascular trunks appear to have been
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 233quite large, extending forward to the anterior fifth of the length of thevalve, but no subdivisions indicating the points of attachment of the dif-ferent muscles have been detected. The pedicle nuiscles were prob-jibly attached to the elevated posterior portion of this central area. Insome casts this posterior area is scarcely elevated above the planeof the interior. In others it is quite prominent.In the interior of the dorsal valve the interior of the deltidial cavitysupports a small, well-developed cardinal process or callosity, and aslight, narrow, median ridge occurs just in advance of the deltidialcavity. The crura are short and well dehned, with relatively shallowdental sockets beside them. The cardinal process and crura vary insize and length in shells from the same locality. The only traces ofthe muscle scars observed show the anterior adductor impressions.The vascular trunks of the dorsal valve diverge from the central lineabout the center of the shell after passing around the adductor muscleimpressions.Observations.?The average size of the typical specimens from Texasis from 10 to l-I mm. in height for the ventral valve, the width beingabout the same. At one locality on Morgan's Creek several dorsalvalves were found that have a width of 18 mm., with a height of12 mm. This ma}" possibly indicate a variety or distinct species, butwith the material in the collection it is impossible to determine itdefinitely. The shells from the upper Mississippi Valley in Wisconsinand Minnesota average about the same size as the typical forms fromTexas. The young shells are much more convex. The material fromthe Gallatin Range, Yellowstone National Park, is also much like thatfrom Texas, but that from the limestone near Malad City, Idaho,while containing typical shells, also has specimens as large as thosefrom Morgan's Creek, Texas.BiUlngsella major differs from B. coloradoensis in the character ofthe surface striation, also in its larger size. B. plicatella is a unformlysmaller and more convex shell, and also has distinct surface characters.The same is true of B. striata.This species has a wide geographic range that extends from Texasto Missouri, Minnesota, and Wisconsin, and westward into Montana,Wyoming, and Idaho. Its vertical range in Texas is limited to theupper portion of the Middle Cambrian, and in Wisconsin and Minne-sota to the St. Croix sandstone from the upper portion of the zone ofthe Middle Cambrian horizon nearly through the zone of the UpperCambrian fauna; in Idaho to the Middle Cambrian; in the upper Gal-latin Valley of Wyoming to the Upper Cambrian; and probably thesame horizon in the Gallatin Valley below in Montana. There doesnot appear to be any specific variation in the shells from Texas, theupper Mississippi Valley, and the Upper Cambrian of Wyoming.FoTination and locality.?Middle and Upper Cambrian.
234 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii,In Texas abundant in the limestones of the Middle Cambrian, atPacksaddle Mountain, Llano Count}'; at Morgan's Creek, HoneyCreek, and Coal Creek Canyon in Burnett County.In Wisconsin, Middle Caml)rian at Trempealeau, below the lifth trilo-])itc bed; also in the upperiuost horizon of the Upper Cambi'ian atthat locality; Middle Cambrian zone at Hudson, at bluff near city and4 miles from Readsburg; Osceola Mills quarry in suburbs of villagenear St. Croix River; Berlin; Winona; Alma; and Menominee.In Minnesota, 4 miles southeast of Lake City; River Junction,Houston, 20 miles below Dresbach; Red Wing; Reads Landing, foot ofLake Pepin; Minneiska.In Missouri, casts of this shell occur in the thin-!)edded magnesianlimestones 50 feet above the conglomerate series in St. Francois County,collected b}' Dr. Frank Nason; at about the same horizon in IronCounty, in sec. 22, T. 8.5, R. IE., collected by Mr. D. K. Gregor.In Montana, Spring Hill Canyon, west side of Bridger Range; eastand west sides of Dr}- Creek above Pass Creek, Gallatin Valley; northand east Gallatin River, near Hillsdale.In Idaho, Gallatin limestone 3 miles southeast of Malad City; also,2 miles southeast of Malad City in limestone resting on the Flatheadsandstones.In Wyoming, Gallatin limestone on the divide at the head of SheepCreek, Teton Range; Crowfoot section, Gallatin Range; also on thenorth slope of the Crowfoot Ridge on the south side of the GallatinValley, and on the divide between Panther Creek and the GallatinRiver.As far as known the species occurs in association with the MiddleCambrian fauna in Texas, Wisconsin, Minnesota, and Idaho. In theTeton and Gallatin Ranges, Wyoming, however, it occurs at the upperlimit of the Cambrian.BILLINGSELLA DICE, new species.In general form and surface this shell is related to B. romingeri. Itdiffers from the latter in its strong dental plates.Formation and locality.?Lower Ordovician (?) The specimens ofthis shell are from a drift bowlder found near St. Albans, Vermont.The lithological characters of the matrix point to the arenaceous lime-stones of the Phillipsburgh formation just north of the United Statesand Canadian boundary as the source of the bowlder.BILLINGSELLA EXPORRECTA Linnarsson.Ortlxu expon-ecta Linnarsson, Bihang till K. Svenska Vet. Acad. Handlingar,III, 1876, No. 12; Brach. Paradoxides Beds of Sweden, p. 12, pi. ii, figs.18-19; pi. Ill, figs. 20, 21.OHhis cxporrcrtd Kaysek, ('ainbrisihe Brach. von IJan Tung, China, Richthofen,IV, 1893, p. 35.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 235Shell transversely siibsemicircular; with the hinge line usuali}^ alittle shorter than the greatest width. In a few examples it is a triflelonger; the cardinal angles are obtusely angular. The proportionsbetween the length and breadth vary. The ventral valve is consider-ably more convex than the dorsal. It is evenly rounded while the dorsal\'a\\q usually has a flattening of the median area, and sometimes a slight,l)road sinus. The surface is marked by numerous radiating costiv andvery flne concentric striae between the costa% and a few visible lines ofgrowth. The cost* are rounded, usually, but not always, broader thanthe interspaces and continuous from the umbo to the front and lateralmargins; they appear to be quite regular, although varying much insize, and increasing somewhat irregularly by interpolation of newcostge; this usually occurs near the umbo, but may occur near the middleof the valve. The largest ventral valve in the collection has a lengthof 9 mm. and breadth of 11 mm. Dorsal valve, length 7 mm., breadth10 mm. Cardinal area of ventral valve high and overhanging theposterior margin. The delthyrium is large and appears to have justa trace of a deltidium about its sides. Cardinal area of dorsal valveshort and slightly inclined forward; it is divided midway by a broaddelthyrium, which is divided by a strong cardinal process.In the interior of the ventral valve, strong, main, vascular sinu.sesextend well forward toward the front margin; the cast of the umbonalcavit}^ opposite the delthyrium shows a tripartite division, the center ofwhich is the area of the path of advance of the diductor muscle impres-sions, and those on each side appear to be the posterior portion of themain vascular sinuses. The anterior edge of the cavity is marked by asharp, elevated, forward arching ridge that extends to the teeth on eitherside; the dental plates appear to have extended to the bottom of thevalve, and to have bounded the sides of the triangular umbonal cavityopposite the delthyrium.The interiors of the dorsal valves are beautifully preserved. Thecardinal process, crura, crural plates, area, anterior and posterioradductor nmscle scars and vascular sinuses are very distinct; the dentalsockets are shallow, but clearly shown. In one specimen there appearto be two lateral supporting septa to the thickening before the cruralplates that bound the spaces occupied by the point of attachment ofthe diductor muscles. Doctor Linnarsson describes the cardinal proc-ess as triangular. 1 find it both straight, subtriangular, and triangular.A short median septum is shown in some shells, but usually the strong,slightly rounded, flattened, median ridge does not carry it.Ohse)"vatio)is.?This is one of the most variable species of the genusboth in external, and, as far as known, internal characters. It is veryabundant but interiors of the ventral valve are rarely met with in goodcondition.
236 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.Doctor Linnarsson compares O. expovrecta with Orthis hicksi whichappeared to be the most nearly related, pointing out that it differedin having fewer and coarser ribs, less pointed beak and lower area.Foriuation and locality
.
?Middle Caml)rian. Zone of Paradoxidesforch/iaiiinierl. I^innarsson's localities are Kinnehiille, Lovened andGudhem in Westrogothia; also at several places in Nesike; at SodraMockleby in Oland; and in loose stones at Lillviken in Jemtland. Instrata with Agnostus laevigatus at Carlsfors in Westrogothia, Sweden.The specimens I have illustrated were collected by M. Schmalenseein Westrogothia.BILLINGSELLA EXPORRECTA, var. RUGOSICOSTATA, new variety.Orthis Mcksi Linnarsson, Bihang till K. Svenska Yet. Acad. Handlingar, III,1876, No 12; Brach. Paradoxides Beds of Sweden, p. 13, pi. in, figs. 22, 23.Doctor Linnarsson recognized that this shell was not the same as hisOrthis exporrecta and placed it provisionally under Orthis hicksi, call-ing attention to the fact that it was nearlj^ related to 0. exporrecta.With a tine series of specimens for comparison I place the shell as avariet}^ of B. exporrecta. It is characterized by its strong irregularcost*. Doctor Linnarsson indicated as the most important differences;
"ventral valve less convex; cast of diductor muscle scars less distinct;dorsal valve more convex and muscle scars more strongh^ marked;radiating ribs in the casts fewer, stronger, and more angular." Allof the differences exist when we compare the extreme forms, but witha good series of specimens most of them pass graduall}^ into forms thatare tj'^pical of J^. exporrecta.Fonnatioii and locality.?Middle Cambrian. Zone of Paridoxidesfordihainmeri. Doctor Linnarsson found this shell at Kinnekulle andLovened in Westrogothia and at Sodra Mockleby in the island ofOland, Sweden. The specimens I have illustrated were collected byM. Schmalensee in Westrogothia.BILLINGSELLA HARLANENSIS, new species.The general form and convexity of this shell is similar to that of B.plicatella. It differs in having a nearly smooth surface marked onlyby fine concentric striae and a few traces of sharp radiating costse.The interior of the ventral valve has very strong main vascular sin-uses and a deep, sharply defined, tripartite umboral area opposite thedelthyrium; the tripartite area is much like that in B. coloradoensisand B. exporrecta. The main vascular sinuses pass directly back acrossthe ridge in front of the tripartite area and occupy the two lateraldivisions of the area. The interior of a dorsal valve, shows an abnor-mal arrangement of the vascular markings and muscle scars.Foniiatlo)) and locality.?Middle Cambrian. Limestone layers inKogersville shale, 4 miles northeast of Rogei'sville and 11 miles north-west of Knoxville, Tennessee.
NO. 1395. CAMBRIAN BRACHIOFODA?WALCOTT. 237BILLINGSELLA HICKSI (Saitcr^^Davidson.^OrlMs liicksi (Salter MS.) Davidson, Geol. Mag., V, 1868, p. ol4, pi. xvi, figs.17-19.(Mills hicksi Davidson, Brit. Foss. Bracli., Ill, 1871, p. 230, ])1. xxxiii, figs.13-16.Ortlilx liicksi Kayskk, Cambrische Brach. v. Lian Tung, China, Kiclitliofen, IV,1893, p. 35.Origltial description.?Shell small, transversely oval; hinge-line shorter than thegreatest breadth of the shell; cardinal angles rounded. Dorsal valve semicircular,moderately convex, slightly longitudinally depressed along the middle. Ventralvalve convex, deeper than the opposite one. Area triangular, moderately wide; sur-face of valves ornamented by about ten principal, narrow, radiating ribs, with wideinterspaces between each pair, in the middle of which is situated a shorter rib.Length about 4, width 5 lines.Obs.? Orthis hicksi is a scarce fossil, and very rarely found, even in a passably com-plete condition. It was discovered by Mr. Hicks in the middle (sandstone) beds ofthe Menevian group at Ninewells and Porth-y-rhaw, near St. Davids, and is the oldestspecies of the genus on record. It has not been hitherto found in North Wales, nor,to my knowledge, in any other locality.This shell is most nearly related to ?. exjporrecta. It differs in itsmore rounded form, fewer radiating ribs and muscle area of ventralvalve.Formation and locality.?Middle Cambrian. Menevian sandstone,as stated above.BILLINGSELLA HIGHLANDENSIS Walcott.Orthis ' highlandensis Walcott, Bull. U. S. Geol. Sur. No. 30, 1886, p. 119, pi.viii, figs. 3, 3a, 3b.Orthis highlandensis Walcott, Tenth Ann. Rept. U. S. Geol. Sur., 1891, p. 612,pi. Lxxii, figs. 5, 5a, 5b.Shell transversely oval or subrotund. Front broadly rounded andnearly straight in the dorsal valve. On the ventral valve the cardinalline slopes toward the beak at an angle of about 20^, while in the dor-sal valve it is less than 10?. The greatest width is about the middle ofthe shell. The ventral valve is moderately convex, being most ele-vated toward the beak, which is slightly arched over to the cardinalmargin.A dorsal valve associated in the same hand specimen of limestone ismore convex than the ventral valve. The cardinal line is shorter atthe greatest width of the shell. The median fold is but slightly raisedabove the general surface, although the front margin has a low, broadarch for the reception of the fold of the ventral valve.There is a slight flattening in the central portion of the ventral valvethat in some specimens forms a low, broad, mesial sinus toward thefront margin.The surface is marked by concentric lines of growth; otherwise itappears to be smooth. Interior casts of the valves show fine, radiat-Proc. N. M. vol. xxviii?04 16
288 rROCEEDINdS OF THE NATIONAL MUSEUM. vol. xxviii.
iiig- stria^ toward the front. In a number of partially exfoliated shellsthe shell is shown to be thick and apparently solid, having been replacedby calcite.The average sized ventral valve has a heighth of 13 mm. with awidth of 16 mm. One dorsal valve is IT nun. in width.Cardinal area of the ventral valve unknown except that its planeextends backward at an angle of about 10" or 15" to the plane of themargin of the shell.Casts of the interior of the xentral valve show that the dental platesextend down to the })ottom of the valve, supporting distinctly definedhinge teeth. The traces of a vascular system are limited to the mainvascular trunks, which extend forward well toward the front margin,very much as in B. coloradoenHU. In one cast there is a strong fur-row extending from a median furrow obliquely outward to each mainvascular sinus. The median furrow extends backward to the apex ofthe cast that tilled the space beneath the umbo and the deltidium.This portion of the cast is also marked by line vertical venation. Inanother cast there is a very narrow median furrow\ These medianfurrows probably indicate the beginning of a septum that in laterforms connected the deltidium with the shell. Nothing is known ofthe interior of the dorsal valve.OhserviUlons.?The original description of this species was basedupon material from which the preceding description is taken, also aspecimen now referred to another species in which the area is nearlyperpendicular.This species is strongly characterized by its nearly smooth surface,in having the dorsal valve more convex than the ventral, and thepresence in the ventral valve of a sharp ridge beneath the umbo,indicating the beginning of the growth of a median septum.Formation and locality.?Middle Cambrian. In the limestone withOlenelhis gilherti. Olenoides levis, etc., at Pioche, and also on the westside of the Highland Range, 11 miles north of Beimett's Springs, andat the south end of the Timpahute Range, Groome District, Nevada.BILLINGSELLA LINDSTROMI Linnarsson.Orthis lindstroml Linnarsson, Biliang till K. Svenska Vet. Acad. Handlingar,III, 1876, No. 12; Brach. Paradoxides Beds of Sweden, p. 10, pi. i, figs. 1-8;pi. II, figs. 9-12.The general description of B. colomdoensis applies to this species.The casts of the interior have the same general flatness of appearanceand the exterior surface.>5 are not unlike. In detail the two differmaterially. The radiating costa^ of B. l/ndstrorni are usuallj^ stronger;the umbo of the ventral valve is more prominent and the beak moreincurved. The interior of the ventral valve shows shorter main vascular sinuses and njore limited ovarian areas.
NO. 1395. CAMBRIAN BRArillOPODA?WALCOTT. 239Doctor Linnarsson gives a fine series of illustrations of the interiorof the ventral valve, which shows that there is considerable variationin the position of tlic vascular markings. He states that the smallcardinal process appears to be bifid. 1 find it single in a natural castin the limestone from Alunbruk. There is also a narrow median sep-tum as in the dorsal valve of B. coloradoensis.Doctor Linnarsson writes:
I do not know any species witli which this can be confonnded. At. least the aduh.specimens are always easily recognized. In the young ones the characters are lessmarked, especially in the dorsal valves. The interior and the internal cast of theventral valve is in all stages of growth easily recognized.Formation and locality.?Middle Cambrian. Zone of Paradoxidesforchhamineri. Kinnekulle and Lovened in Westrogothia, Island ofOland, at Sodra Mocklebv and Alanbruk, Sweden. Doctor Linnars-son also found it in loose stones at Lillviken Jemtland. The speci-mens I have illustrated were collected by M. Schmalensee at Alanbruk.BILLINGSELLA MAJOR, new species.In general form andconvcxit}- this shell is related to B. coloradoensis.It differs from it in being larger and in having coarser radiating ribs.It is the Upper Caml)rian representative of the latter species.FoTinatlon and locality.?Upper Cambrian. Fine grained, l)uli'colored sandstone in excavation on Wells' farm, 2 miles west of Bar-aboo, Wisconsin.BILLINGSELLA OBSCURA. new species.This species is founded on a single dorsal valve that occurs in theform of a cast in sandstone. It is transverse, width 18 mm., height13 mm. ; moderately convex with a slightly defined mesial flatteningthat broadens out nearly to three-fifths the width of the shell at thefront margin. The surface of the cast is marked by a few faintlydefined, rather broad costse.The shell is much like the large dorsal valves of B. cohyradoensh.It differs in its broader frontal margin and median flattening.Forniation and locality.?Middle Cambrian. Thin bedded sand-stones just above the massive Tonto sandstone near the head of Nun-koweap Valley, Grand Canyon of the Colorado, Arizona.BILLINGSELLA ORIENTALIS Whitfield.
Ch'thisina orientalis Whitfield, Bull. Amer. Mus. Nat. Hist., I. 1884, p. 144,pi. XIV, tig. 6.Orthisina orientalis Walcott, Bull. U. S. Geol. Sur.. No. 30, 1886, p. 120,pi. VII, fig. 6; Tenth Ann. Rept. U. S. Geol. Sur., 1891, p. 613, pi. lxxii, fig. 8.BillingseUa orientalis Hall and Clarke, Pal. New York, VIII, 1892, Pt. 1, p. 230.Original description.?Shell quadrangular in outline, somewhat higher than wide,with vertical and subparallel lateral margins and broadly rounded base. Cardinal
240 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.line rapi<ily slopinjj from the apex to the extremities, which are slightly rounded.Hinge line straight, as long as the greatest width of the shell. Cardinal area broadand high, divided in the middle by a triangular foramen, which is about as high aswide. Surface of the venti'al valve nioileiately convex, marked by very fine radiat-ing stri;c and also by several concentric lines of growth. Filling of the rostral cavityand foramen large and prominent. Specimen, a cast in shale, of the ventral valveonly.()h,<<('rn(itl<))i.s.?The type specimen as descri])ed above is flattened inthe shale, and also appears to be compressed laterally. Uncompressedspecimens referred to this species from the siliceous limestones east ofSwanton show the ventral valve to have been rather stron^^ly convex,and the dorsal valve moderately so. The outer surface as shown inthe cast, indicates that it was somewhat like that of B. coloradoensis.,but that it differs in having tiner and more numerous thread-likecostas. A few traces of concentric stria? and lines of growth are pre-served. The material is very unsatisfactory, but it is sufficient toindicate that the genus occurs in association with Olenellus thompsoniin the upper beds of the Lower Cambrian section.Foruiation and locality.?Lower Cambrian. Georgia terrane.Silico-argillaceous shales: Parker's quarr}^, town of Georgia; and ina gray siliceous limestone lentile, 2 miles east of Swanton, Vermont.BILLINGSELLA PLICATELLA, new species.Shell irregularly sulxjuadrate in outline. In the ventral valve thecardinal line slopes toward the beak at an angle of from .5? to 10?,while in the dorsal valve it is usually about 1? to 3?. The greatestwidth of the shell is about the middle. There is some variation in therelative proportions of length and breadth. Usually, however, theventral valve is fully as high as wide, while in the dorsal valve it isslightly transverse. The ventral valve is rather strongly convex, thedorsal valve being less so. A low, broad, mesial sinus occurs on nearlyall specimens of the dorsal valve, and sometimes a distinct sinus on theventral valve.The surface is marked by costai that gives it a plicated appearancein many specimens; also concentric lines of growth and very fine,slightly undulating strife. On some shells the costae and surfacemarkings have been almost entirely removed by abrasion, while inothers they are clear and distinct. There is quite a wide range ofvariation in the strength and form of the surface markings.When the shell is exfoliated, fine, radiating lines occur toward thefront margins. The average size of the shell gives a width of about8 mm., and in the ventral valve a nearly equal height. One specimenhas a width of 11 mm.Cardinal area well defined. It is marked by transverse stria? ofgrowth parallel to the base. The plane of the area extends backwardover the cardinal line at an angle of 10-^ to the plane of the margin of
NO. 1395. CAMBJU. I .V BRA CFTTOPODA? WALCOTT. 241the shell. The deltli\ liiiiii is well dctined mikI covered by a convexdeltidium, the extent of which, however, is unknown. The cardintdarea of the dorsal valve is short. No details of the structure havebeen observed.The cast of the interior of the ventral valve indicates short hingeteeth supported b}' dental plates. The markings left on the shell bj^the vascular system, as shown in casts, are two main vascular trunkswhich extend nearly in a straight line from the side of the cast of thedeltidial cavity obliquely outward to the anterior fourth of the valve,where they bifurcate. The inner branch extends in toward the medianline, while the lateral branches extend outward, appearing to unitewith the peripheral canal. The latter arches about the space that wasprobably occupied by the ovarian areas, between itself and the mainvascular trunks. The spaces for the attachment of the muscles betweenthe main vascular trunks appear to have been large. No subdivisionindicating the points of attachment of the different muscles have beendetected. At the posterior portion of the central area there is anarrow, elevated space that posteriorly passes into the deltidial cavity.The pedicle muscles were probably attached to the front part of thiselevated space. Short, radiating striae near the margin indicate the])resence of minute vascular canals.In the interior of the dorsal valve the interior of the deltidial cavitysupports a small, well-developed cardinal process or callosity. Thecrura are short and small, with rounded dental sockets beside them.Nothing is definitely shown of the vascular trunks or mesial impres-sions in the dorsal valve.Ohservationx.?This very pretty little species occurs in large num-bers in the Gallatin limestone, Montana. In form it is not unlike theconvex forms that have been referred to B. coloradoensis from Trem-pealeau, Wisconsin. It differs from the latter in having stronglj"marked surface plications and a narrower deltidium. From B. striatait differs in surface characters; also in having a more convex dorsalvalve.Formation and localities.?Upper Cambrian. Gallatin limestone,east side of Dry Creek, above Pass Creek, Gallatin Valley; west sideof Dry Creek not far from mouth of Pass Creek; north of East Gal-latin River near Hillsdale; on ridge between Churn and Cottonwoodcanyons, west side of Bridger Range, Montana.All representatives of this species were collected by Dr. A. C. Peale,of the Hayden survey, except some obscure specimens 1 found at thebase of the limestone above the Flathead shales G miles north of York,in the Big Belt Mountains, Montana.
242 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvni.BILLINGSELLA PUMPELLYI, new species.General outline subsemicircnlar, greatest width at the hinge line ora little in advance of it; considerable variation exists in the relativeproportions of length and width; a ventral valve 8 nun. long has awidth of 9 mm.; the dorsal valve is more transverse, length 5.5 mm.,width 8 mm. The ventral valve is strongly convex with the umboarching over to the apex, which is a little above the plane of the mar-gins of the valve; a very slight median fold occurs near the front mar-gin; dorsal valve slightly convex and with a shallow median sinus.The surface is marked by low, sharp ribs with wide interspaces, onwhich fine radiating stria) occur. Concentric lines and stripe of growthcross the radiating striw and ribs.The characters of the cardinal areas of the valves are almostunknown; that of the ventral valve appears to have been of moderateheight and inclined but a little from the plane of the valve; one inte-rior of the dorsal valve shows a low cardinal process. The cast of theinterior of the ventral valve shows the presence of a tripartite elevatedumbonal space into which the strong main vascular siiuises extend, asin BhllingtieUa, coloradoensls,' the sinuses extend forward nearly to thefront margin of the valve. Of the interior of the dorsal valve onlythe presence of a strong median ridge is known.Ohservations. ?This, species is one of the costate forms of the typeof B. coloradoensis and B. Tomingeri. It differs fi'om them in surfacecharacters. It may be considered the trans-Pacitic representative ofB. coloradoensls.The specific name is given in recognition of the work of RaphaelPumpelly upon the geology of China.Formatkm and locality.?Middle Cambrian. Chao Mi Tien lime-stone. Three miles southwest of Yen Chuang, also Chao Mi Tien,Shantung, China. Collected by Eliot Blackwelder and Bailey Willis,of the Carnegie Institution Expedition, 1903.BILLINGSELLA RICHTHOFENI, new species.This species is represented by two specimens of the exterior of theventral valve. They vary from 4 to 5 mm. in length and width, thelength and width being about the same. The outer surface is markedby fine, obscure, radiating ribs and very fine concentric stria;. Thegeneral form is much like that of the ventral valve of BiUIngsellapumpellyL It difi'ers from the latter in having a shorter hinge linein proportion to the width, the more uniform and stronger convexityof the surface, and the more elevated apex.The species is named after Dr. Ferdinand von Richthofen.
NO. 1395. CAMBRIAN BRA OHIOPODA? WALCO TT. 243Foriuaflo)) (ind Jocrillfi/.?Middle Cambrian. Chang H.sia liniestonc.Two and one-half miles south of Yen Chuang, Shantung-, China.Collection of Mr. Eliot Blackwelder, Carnegie Institution P]xpedi-tion to China. BILLINGSELLA ROMINGERI Barr.Orthh romingeriBARR, Ueber die Brachiopoden der Sil. Schi. Bohmen, II, Abth.Haidingers Naturw. Abhandl., II, 1848, pp. 203, pi. xvii, fig. 8.Orthis romingeri Barr, Syst. 811. BiJheme., V, 1879, pi. lxii, figs. 1-4.fhihis romingeri Pompeck.i, Die Fauna des Cambrium von Tejfovic und Skrej inBohmen, Jahrbuch der k. k. geolog. Reichsanstalt, 1895, XLV, 1896, Pts.2 and 3, pp. 513, pi. xv, figs. l-5a.Shell transverse, the general outline being irregularly subquadrateto subsemicircular. On the ventral valve the cardinal line slopestoward the beak at a low angle, while in the dorsal valve it is approxi-mately straight. In some shells the greatest width is at the hingeline, while in others it is about the middle of the valve. There is con-siderable variation in length and breadth.The ventral valve is rather strongly convex and the dorsal valvemoderately so. The dorsal valve is slightl}^ flattened from the umbo tothe frontal margin, the flattening sometimes taking the form of a shal-low depression. A low, })road, mesial sinus occurs on the dorsal valvethat is strongly marked in the young shells. The surface is markedby rounded, bifurcating, radiating costse, crossed bj^ concentric lines ofgrowth and undulating concentric striae. The radiating costse vary insize and character in specimens from the same locality. In some speci-mens they are very regular, while in others there will be wider inter-spaces or a variation in the manner of interpolation. The ridges ofgrowth also vary in strength and elevation in diflerent shells.The largest shell in quite a large quantity of material has a heightin the ventral valve of 13 mm. and in the dorsal valve of 10 mm., witha width of 15 mm. Cardinal area of ventral valve rather high andslightly incurved; it is marked by transverse stria? of growth thatcross it parallel to its base; the plane of the area extends backward atan angle of about 10'-' to the plane of the margin of the shell; thedelthyrium is rather large; a deltidium is indicated in some of thecasts, but none of the specimens show it clearly. The cardinal areaof the dorsal valve is about one-half the length of that of the ventralvalve. It extends backward at an angle of more than 45? to the planeof the margin of the valve, and is divided midway by a strong delthy-rium, which is covered, for a part of its distance at least, by a convexchilidium.The traces of the vascular system in the ventral valves are seen inthe main vascular trunks which extend well forward toward the frontmargin, where they appear to bifurcate, the inner branch extendingtoward the median line, and the lateral branches api)arently connect-
244 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.
iiio- with the ])oriphcral canal tliat aiches ])ackvvar(l jiliout the ovarianareas between it and the main vascular trunks. No points of attach-ment of the various muscles in the ventral valve have been observed.Th(?, area in whicih the diductor muscles are attached is well marked insome specimens, and the cardinal process of the dorsal valve in others.There are also shown in the dorsal valve the anterior adductor impres-sions. In the interior of the dorsal valve the deltidial cavity separatesa small cardinal process or callosity, which is straight or subtriangular.The crura are relatively" long- and \'ery pi'ominent, with distinctlydefined dental sockets beside them.Oh^iervations.? This species was well illustrated by M. Barrand.In the material of the collections of the Museum of ComparativeZoology, Cambridge, Massachusetts, there is a fine series illustrating-the interior of the ventral and dorsal valves, that through the kindnessof Dr. Alexander Agassiz I was enabled to study.The species in its external and internal shape varies so decidedlyfrom all described forms that it is not necessary to point out difi'er-ences between them.Formation and locality.?Middle Cambrian. Argillites and fine-grained sandstone near Skrej, Bohemia.BILLINGSELLA SAFFORDI, new species.General outline of ventral valve subsemicircular and of dorsal valvetransversely broad oval; greatest width of valves at about the center;hinge line straight and a little shorter than the greatest width of theshell. A typical ventral valve has a length of 9 mm., width 9 mm.Dorsal valve, length 10 mm., Avidth 12 mm. Biconvex, the ventralvalve being- more elevated at the umbo than the dorsal. Surface asfar as known smooth or marked bj" concentric strise and lines ofgrowth.Ventral valve with umbo curving- over and terminating in the smallapex that incurves a little over the area; area about one-half the ele-vation of the valve, a broad delthyrium is partially covered by aconvex deltidium; casts of the interior indicate a low, tripartitepseudospondylium, and one cast shows strong main vascular sinusesextending from the lateral divisions of the pseudospondylium nearlyto the front margin. Dorsal valve with low area and small pseudo-cruralium; th(> casts are too imperfect to show any other details.Ohservatvmx.?This species occurs in the same region as B. liarlan-ensin and also has a smooth shell; it differs in being of equal lengthand ])readtli and in having- less strongly marked interior characters.The species is named after Prof. James M. Safi'ord, former Stategeologist of Tennessee.Foi'iitutioii andlocality.?Middle Cambrian. Rome sandstone, alongFirst Creek Cap, 4 miles north-northc^ast of Knoxville, Tennessee.
CAMBRIAN BRA CHIOPODA? WA LCOTT. 245BILLINGSELLA SALEMENSIS Walcott.
OrfJiis saletnen^ifi Wau'oit, Aiiier. Jour. Sci., 3d ser., XXXIV, 1887, p. 190,pi. I, figs. 17, 17a; Tenth Ann. Eept. U. S. Geol. Sur., p. 612, pi. lxxii; figs^.6, 6a.Shell about the average size of the Cambrian specii's of the genus.Transversely subquadrilateral; front broadly rounded and slightlysinuate midway; hinge line as long as the greatest width of the shell.Ventral valve convex, most elevated about one-fourth the distancefrom the beak to the anterior margin; beak small and incurved to themargin of the medium-sized area; the surface of the area and theforamen have not been observed; mesial sinus broad and shallow,marked b}^ a low median rib and laterally by two costfe on each side,a third appearing just outside the sinus.The dorsal valve, associated in the same hand specimen of limestone,is slightly more convex; frontal margin with a rather deep sinuosityto receive the projection of the ventral valve; median fold broad andl)ut slightly elevated, marked by two or three low costse; the beakappears in the broken specimen in the collection to be scarcelv elevatedabove the surface of the shell, and to terminate at the cardinal margin;area unknown.The surface of both valves is marked by fine concentric lines ofgrowth, and low, rounded costee, varying in number from six to seven.In the broad costaj and the general aspect of the shell this species isunlike any known to me from the Cambrian, with the exception ofB. inhitfieldi^ from which, however, it differs in strength and characterof costse and outline of valves.Formation and localities.?Lower Cambrian; limestone interbeddedin the shal}^ slates li miles south of Salem; 1 mile south of Shushan,and near Rock Hill school house (No. 8), Greenwich, WashingtonCounty; bedded limestone of Olenellus zone on north side of BemanPark, Troy, New York. It is also present in limestone bowlders of theCambrian conglomerate at Metis, on the St. Lawrence, below Quebec.Olenellus sp. HyolitheUus inicans., etc., occur in association with it.Cat. U. S. Nat. Mus., No. 17443.BILLINGSELLA STRIATA, new species.The form of the ventral valve of this species is much like that ofB. jdicatella. It differs in having a finely striated outer surface, andin the strong development of the main vascular sinuses and the broader(leltidial cavity. The only two specimens of the dorsal valve areiiearl}^ flat.Formation and locality.?Middle Cambrian? The character of thematrix indicates that the specimen came from the Flathead formation.Forks of Pole Creek above Cherry Creek Valley, Madison County,Montana.
246 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvni.BILLINGSELLA WHITFIELDI Walcott.Kulorgind whitfidili Waiaott, INIong. U. S. Geol. Sur., \'1II, 1884, p. 18, \A. ix,fifj;s. 4, 4a.Bil/hKjscllo whiljiddi SrnucHERT, Bull. U. >S. Geol. Sur. No. 87, 1897, \). 159.Shell convex, hinge line straight and a little less than the greatestwidth of the shell, sides rounding regularly into the slightly convexfrontal margin.Ventral valve quite convex, elevated along the center to form a flatdepressed fold, and sloping quite rapidly from this to the lateral andcardinal margins; median elevation with about five rather faintlydefined, simple plications, that reach up to the higher portion of thevalve; beak small, a little depressed, and rising alwve the area; cardinalmargins straight and diverging from the beak at an obtuse angle;character of area unknown.Dorsal valve depressed convex, with a rather wide, shallow, mediandepression, and two short plications on each side of it toward thefront, which are obsolete in some of the specimens; the area betweenthe cardinal edges and the elevation of the sides of the mesial depres-sion is depressed and corresponds to the flattened lateral slope of theventral valve.Surface marked by fine, very clearly defined concentric stride thatare crowded together into narrow ridges and are subparallel to thefront and lateral margins of the shell.I>. wh/tjleldi belongs with the group of species including B. sale-wte7isis or shells with coarse plications and very fine concentric stride.The latter species occurs with the Olenellus fauna in eastern New York,and B. whitfieldl in the Middle Cambrian of Central Nevada.Formation and locality.?Lower Cambrian. Prospect Mountaingroup, beneath the Secret Canyon shah?, on the west side of SecretCanyon, Eureka District, Nevada.OTUSIA, new subgenus of BILLINGSELLA.This name is proposed to include Ort/ds sandhergl of N. H. Winchell,which is the only species known at present. The subgeneric and spe-cies characters are included in the description of the species,BILLINGSELLA (OTUSIA) SANDBERGI Winchell.Ortliis sandhergi N. H. Winchell, Fourteenth Ann. Rep. Geol. Nat. Hist. Sur.Minnesota, 1886, p. 318, pi. ii, figs. 8, 9.Orthis f sandhergl Walcott, INIong. XXXII, U. S. Geol. Sur., 1899, p. 452, pi.Lxi, figs. 2, 2a-(l.Shell small, transverse, subquadrate in outline, exclusive of theacute cardinal extremities. Valves slightly convex, with a straighthinge line longer than the greatest width of the shell; cardinal areanarrow but well developed on each valve and divided by a rather largeopen delthyrium.
NO. 1395. CAMBRIAN BRACIIIOPODA?WALCOTT. 247The ventral valve slijihtly flattened at the cardinal extremities, risingtoward the center with a convex triangular swelling, broadening fioiuthe narrow beak to the front; beak small, rounded, and extendingslightly beyond the hinge line. Dor.sal valve flattened at the cardinalextremities, with well-marked rounded ridges rising between them,and a rather broad, well-defined median sinus; beak very small, slightlyencroaching upon the hinge line.Surface marked by flne, regular, radiating striae, between whichone or more faint intermediate strige are sometimes visible; underfavorable conditions very fine concentric stride can be seen, and thereare also usually present more or less distinctly marked lines of growth.Very little is known of the interior of the ventral valve. Two frag-ments of the posterior portion show a broad delthyrium, strong teeth,and a broad umbonal cavity opposite the delthyrium. In the ventralvalve the area is narrow and divided by a broad delthyrium, whichhas a strong cardinal process that extends forward nearly three timesthe length of the area. Anteriorlv, it rests on a broad ridge thatextends forward, gradually broadening out and disappearing at theanterior margin of the shell.In my former description ? I stated that "the generic character ofthis species has not been fully ascertained, but the material from theYellowstone National Park and specimens from the typical locality atRed Wing, Minnesota, lead me to think that this can not be referredto the genus Blllingnella. It appears to be an Orthis of the Plector-this group of Hall and Clarke." A more thorough study of this spe-cies and the forms referred to BiUhigseIJa leads me to place it in asubgenus of Billingsella on account of its surface character, the char-acter of the delthyrium in the two valves, and the strong cardinalprocess and median ridge in the dorsal valve.A comparison of the specimens of this species from a typical localityat Red Wing, Minnesota, with those from the Yellowstone NationalPark, shows the two shells to l^e speciflcally identical as far as thecomparison of casts in sandstone can be made with well-preservedshells on the surface of limestone. This is the only species of this typeknown to me in the Cambi'ian fauna.Formation and locality.?Vp-pev Cambrian. St. Croix sandstone,Red Wing, Minnesota. Upper Gallatin limestone, north side of ElkPass, between Buffalo and Slough Creeks, Yellowstone National Park,Montana. NISUSIA, new genus.Form subquadrate to transversely semioval. Shell substance fibrous;surface with narrow, radiating ribs that support irregularly distributedspines on their crests.
?Mong. XXXII, U. S. Geol. Siir., p. 453.
248 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvui,Ventral valve elevated and usually much more convex than thedorsal, tuid in most species a mesial sinus appears on it. Area high,vertical, or inclined backward; delthyrium large and partially closedwith a convex deltidium; teeth strong and supported by dental platesthat extend outward, also inward forming on the inside a shallow spon-dylium. Dorsal valve moderately convex with onl}' a trace of a medianelevation; usually the surface is convex, but it may be slightly concavefrom the umbo to the margins; crura well developed with the cruralplates extended so as to form a shallow cruralium. No traces of acardinal process have been observed in the dorsal valve.Type ofgenus.? Orthis festinata Billings. Lower Cambrian. Onlyone other species is now known, JV-lsusia alberta from the MiddleCambrian horizon.The species referred to JV-isusia and the subgenus Jamesella are:
Name.
1. alberta, new species2. festinata Billingsfestinata var. trdiisversa WalcottJamesella, new Mil),!,'i_-nus of Nisusia.1. {Jamesella) aiirii, new species2. (J.
)
anjenta, new .tpecies3. ( J. er'ecta, new species4. ( J. kuthani Pompeckj5. (J. perpasta Pompeckjperpasta var. macia Pompeckjperpasta var. subquadrata Pompeckj6. ( J . utakensis, new species7. (J.) species undetermined
Cambrian.M. U,
NISUSIA ALBERTA Walcott.Orthisina alberta Walcott, Proc. TJ. S. Nat. Museum, XI, 1888, p. 442.BilMngsella alberta Schuchert, Bull. U. S. Geol. Sur. No. 87, 1897, p. 158.Orthisina alberta Matthew, Trans. Roy. Soc. Canada (ser. 2), VII, 1902, Sec. 4,p. 109.Shell transversely suboval, front broadly rounded; the straight hingeline is shorter than the full width of the valves. Surface of shell withnumerous radiating ribs that increase by interpolation; on a shell19 mm. in width there are four ribs near the front margin in a distanceof 3 mm. ; the ribs are rather narrow and sharp crested, the inter-spaces being wider than the ribs.. A cast of the outer surface of ashell in silicious shales shows numerous strong spines irregularly dis-tributed on the ribs very much as in iV^. festifiata.Ventral valve elevated at the umbo and apex in some shells, convexand rounded over toward the area in others; area varying in heightin different shells, usually elevated and overhanging the hinge line, itis divided by a strong delthyrium that is covered by a convex deltidiumof varying length, arched at its front margin and divided by longi-tudinal lines into three parts.
No.i3y5. CAMBRIAN BRACHIOrODA?WALCOTT. 249Dorsal valve gently convex; area low and a little inclined over thehinge line; delthyriuni broad with a narrow chilidiuni. Casts of theinterior show a broad, well defined pscudocriiraliuni, and just inadvance of it the adductor muscle scars.Ohservation.s.?This species recalls at once N. fe-sthxitahy \i>^ ele-vated ventral valve and spinose surface; it differs from it by its trans-versely suboval outline, large umbonal muscle cavity (pseudocruralium)in the dorsal valve, and sharp-crested ribs. N'. {Jamesella) perpantahas the general form and surface characters of this species. Amarked difference in appearance is caused by N. alberta occurringin a silicious shaly matrix and H. {Jamesella) perpada as casts in a(juartzitic sandstone and the strong- surface spines of iV! alherta aresparingly represented on the latter.Formation avd locaUty.?W\^d\Q Cambrian. Mount Stephen shale,2,000 feet above Olenellus zone, Mount Stephen section. BritishColumbia.The original specimens were from the collection of Dr. Karl Romin-ger. I now have material lielonging to the Geological Survey of Can-ada, United States National Museum, and Mr. Byron E. Walker, ofToronto, Canada. NISUSIA FESTINATA Billings.Orthisina festinata Billings, Geol. Sur. Canada, Pal. Foss., I, 1861, p. 10, tigs.11, 12; Geol. Vermont, II, 1862, p. 949, figs. 350-352; American Jour. Sci.,2d ser., XXXIII, 1863, p. 105; Geol. Canada, p. 284, fig. 289.Orthisina festinata Walcott, Bull. U. S. Geol. Sur. No. 30, 1886, p. 120, pi. vii,figs. 7, 7a, 7b; Tenth Ann. Kept. U. S. Geol. Sur. 1891, p. 613, pi. lxxii,figs. 7, 7a, 7b.BiUingsellafestinata Hall and Clarke, Pal. N. Y., VIII, 1892, Pt. 1, p. 230.General form subquadrate to transversely semioval, with the cardi-nal extremities subacute to obtusely angular. Hinge line straight,usually equal to or greater in length than the width of the body of theshell. Shell substance fibrous.Surface with narrow, rounded, radiating ribs, that increase by bothbifurcation and interpolation; the ribs are roughened by concentriclines and ridges of growth that arch about the base of strong, acutespines; the spines are located on the ribs, usually just back of a ridgeof growth; they are in more or less irregular, concentric rowstoward the front of the shell, but on the central portions they may bescattered without any system of arrangement; each spine is larger atthe base, tapering rapidly, and curving gradually backward at aboutone-half its length.The ventral valve is more or less elevated at the umbo and apex; insome examples it is subpyramidal, where the height is to the length as3 to 6, and width 9 mm.; in other shells the proportion is 4 to 11, andwidth 17 mm.; the slopes from the apex to the margins are nearly"straight or slightly convex; the form of the umbo and apex varies from
250 rUOCKEDlNGS OF THE NATIONAL MUSEUM. voi. xxviii.a broad rounded umbo, terminating- in a minute beak curving over thearea, to an erect, vertical, more or less rounded a[)ex, with a broadbase rising abruptly from the elevated umbo; a shallow, rounded,median sinus occurs on most individuals, but it is sometimes absent.Area high, and crossed by transverse lines of growth; it is usuallyinclined over the hinge line, but it may be vertical or inclined for-ward; it is divided by a strong delthyrium, which is covered ])y a con-vex deltidium that the author of the species. Doctor Billings, describesas perforate at the apex."I have not been able to verify this in a large collection of material fromvarious localities; casts of the interior of the extended beak indicatebut do not prove that there was a perforation; the front edge of thedeltidium is arched so as to leave a space of variable height between itand the plane of the hinge line; in three examples the area is dividedinto three parts 1)}^ longitudinal lines, two of the lines ])ound the del-thyrium, and one on each side corresponds in position to the "' flexure ""lines in (JhoJiiK and Ilippariony.r. A cast of the interior of a low ven-tral valve shows a broad delthvrium, strong teeth, and supporting den-tal plates, which are produced on the inside, so as to form a short,elevated base (pseudospondylium), pi-obably for the adductor nuiscles,and on the outside the plates are continued partially about the spaceoccupied by the points of attachment of the diductor muscles.The dorsal valve is moderately convex at the uml^o, sloping gentlyfrom there to the margins; usually the slope is (convex, but in oneexample it is slightly concave; area narrow and vertical or slightlvinclined over the hinge line; casts of the interior show the crura,points of attachment of posterior adductor scars, and area of attach-ment of diductor scars. Vascular and ovarian markings unknown.Observations.?This shell has a wide geographic distribution. I havecollected it at the type locality in the township of Georgia, Vermont;at Bic on the lower St. Lawrence River, and near the city of York atEmigsville, in central Pennsylvania. The matrix at Bic is a finelygranular, slightly arenaceous limestone, in which the outer form ofthe shell is well preserved, but the spines are rarely seen; at Swantonand Georgia, Vermont, the shell occurs in siliceous limestone and are-naceous shale, and a cast of the outer surface shows the spines; thematerial from the tinely arenaceous limestone at the Emigsville locali-ties, discovered by Mr. E. Wanner, of York, is the best preserved,and affords excellent casts of the interior and exterior of the valves.In all of the localities the variation in the form and elevation of the
? Through the courtesy of Dr. J. F. Whiteaves, of the Geological Survey of Canada,I had the opportunity of examining the types of Orthisina festinata. None of thempreserve the apex of the deltidium, so it is impossible to determine upon what Mr.Billings based his statement that the deltidium is perforate.
NO- i^w"^- CA MBL'L [X nh'A ('HIOPODA? WA LCO TT. 251
ventral valve occurs, specimens of the ventral valve from Bic show ashorter deltidium than is usually present.A num]>er of exfoliated shells occur in the collection from the dark
^n-ay compact limestone of eastern New York that are womewhatdouhtfully referred to this species.\ii<H!:<la festhiata is a strongly marked species that appears to havehut one near representative in N. {Jautesella) perjMsta. The latter(litters in the absence of spines and form of the ventral valve.Formation and locality.?Lower Cambrian. Upper portion ofOlenellus zone, Georgia formation. In limestone 'Mentile" a))out 2miles east of Swanton; in silico-argillaceous shales, with Olenellusthomjysoni, Parker's quarry, town of Georgia; and in arenaceousmagnesian limestone about 2 miles east of Highgate Springs, FranklinCounty, Vermont. Also in dark gray limestone interbedded in siliceous shales 2 miles south of Middle Granville, Washington County,New York.In limestone bowlder of the conglomerate on the east side of theentrance to Bic Harbor. Province of Quebec. Fragments of Olenelhisand Mlcrodiscus occurred in association with A\ festinata in the lime-stone bowlders.Emigsville limestone, on left })ank of Codorus Creek, below MeyersMill, near Emigsville, 4 miles from York, Pennsylvania.NISUSIA FESTINATA TRANSVERSA Walcott.Orthisina ? transversa Walcott, Bull. U. S. Geol. Sur. No. 30, 1886, p. 121, pi. vii,figa. 5, 5a.Original description.?Shell small, transversely eubquadrangular in outline, frontbroadly rounded, angle formed by the union of the cardinal slopes of the ventralvalve 155? to 165?, hinge line straight and as long as the width of the shell. Area ofthe ventral valve of moderate height, bent back from the hinge line, divided by atriangular foramen that is higher than wide, and covered by a convex deltidium; thearea of the dorsal valve is bent back at more than aright angle to the hinge line;foramen higher than wide, covered by a deltidium.Surface marked by numerous radiating, fine, even costse, eight in a distance of3 mm., on the frontal margin of the ventral valve; a few concentric lines of growthcross the radiating c'ostae, but not so as to give them a nodose character.Interior characters unknown. The fine radiating strias and transverse form dis-tinguish this from other described species known to me.Since 1886 I have obtained a much larger series of specimens, anddo not think that this form should be considered more' than a variety-of iV. festinata.Formation and locality.?Lowei' Cambrian, Georgia formation.Silico-argillaceous shales of Parker's quarry, town of Georgia, Frank-lin County, Vermont.
252 rnOCEEDlNGS of the national museum. vol,. XXVIII.JAMESELLA, new subgenus of NISUSIA.There are several .species of Lower Cambrian V)rachiopods that differfrom Alsu.siafei<:trnata in the absence of the strong- spines on the radi-atini;- ribs. This character is so marked that I separate the specieswithout it as a siibgeneric j^roup. Tlie subgeneric name is in memoryof Dr. Joseph F. .Tames.Type of subgenus, OrtJih perpasta Pompeckj.NISUSIA (JAMESELLA) AMII, new species.Ventral valve convex, elevated at the umbo, with the beak slightlyincurved; area high, vertical, slightly incurved; delthyrium triangular,higher than its greatest width and covered by a convex deltidium,which is imperforate. Surface of shell marked by numerous tine,rounded, equidistant ribs that increase by interpolation; about 8 ribsin a distance of 2 mm. at frontal margin. Size: Length, 8 mm,;width, 10 mm.; elevation at umbo, 4 mm.The front margin of the deltidium broken so that it is impossible tostate whether it was arched as is the deltidium of Nhusia festlnata.There is no trace of a foramial aperture in the deltidium. The line,regular ribs and high area serve to distinguish this from other speciesof the genus. Dorsal valve unknown.The specific name is that of Dr. H. M. Ami, of the CanadianGeological Survey.Formation and locality.?\jOwqv Cambrian. I found this shell in alimestone bowlder of the Sillery conglomerate in association with frag-ments of Olenellus, 4 miles below Quebec, on south shore of St. Law-rence River, Canada.NISUSIA (JAMESELLA) ARGENTA, new species.OnW the ventral valve is known of this species. Its outline is sub-rectangular with hinge line a little shorter than the greatest width.Strongly convex with a keel-like median elevation extending from theincurved beak over the elevated umbo to the front margin, with gradu-ally increasing width. Surface marked b}" fine, concentric stride ofgrowth and about five sharp, elevated radiating ribs on each side ofthe two ribs on the median ridge. Area low, wdth the minute beakcurving down to and possibly slightly over it.This shell is represented by two specimens that have such strongcharacters that 1 unhesitatingly give them a specific name. The onlyform known to me that resembles them is N. (./.) kuthani of Bohemia.Formation and locality.?Lower Cambrian. In shaly limestonecontaining fragments of Olenellus. Three miles southeast of BarrelSpring, one-half mile east of road. Silver Peak District, Nevada.
CAMBRIAN BRACHIOPODA? WALCO TT. 253NISUSIA (JAMESELLA) ERECTA, new species.General form transverselj semioval; hinge line a little shorter thanthe greatest width; valves sabequally convex. Surface marked bystrong, broad, sharply rounded ril)s, three at the frontal margin in adistance of 2 mm. ; the ribs appear to be simple and un))ifurcated fromthe umbo to the margin, but owing to the small size of the shell thisstatement may be modified by discovery of other specimens.Ventral valve convex; elevated at the umbo, apex worn by attrition,but marginal. Area high, very slightl}' inclined backward; delthy-rium large, triangular, length and width equal: deltidium convex,imperforate, and nearly covering the delthyrium. Dorsal valve regu-larly convex, most elevated at the umbo and curving over to the ratherlow area.This species is distinguished by its strong, regular ribs and theregular convexity of the dorsal valve.Fonnatio}! and locality.?Middle Cambrian. Limestone at thesouth end of Timpapute Range, Groomc District, Nevada.NISUSIA (JAMESELLA) KUTHANI Pompeckj.Orthis kuthani Pompeckj, Jahrbuch k. k. Geol. Reichsanstalt, XLV, 1896, p. 514,pi. XV, figs. 8-13.{Orthis romingeri Krejci, Novak, K. Feistmantel, Knsta, Katzer, Wentzel, Jahn.
)
Original description.?Outline subrectangular, hinge edge straight with angles pro-tracted but a short distance; length to breadth as 3 : 4, often less.Ventral valve highly arched. Apex drawn forward, but not curved toward thedorsal valve at all, or in rare cases but slightly. Area high, steep, with sharp arealedges and high, triangular foramen. Owing to the state of preservation, the detailsof the inside of the valves can not be well observed.Dorsal valve flatter, with rather decided arching on side edge and frontal edge, withsinus always distinct, which corresponds to a faint swelling at the frontal edge of theventral valve. The area is very low with a small triangular foramen. Crural proc-esses narrow, considerably divergent.The surface is ornamented with narrow sharp ribs, increasing by interpolation.The ribs are divided by interspaces which are considerably broader than the ribs.In the interspaces there is frequently seen a lower, thread-like rib. The number ofribs is 30 to 36. The ribs are mostly very distinct on the internal casts also. Some-times internal casts are found which show remarkal)ly few ribs, and which in thisrespect and also by their greater breadth approach Orthis perpasta var. macra.The present species has thus far been called, after Kusta's example, Orthis romin-geri, but it differs from that species (?) in the ventral valve, its apex never being sostrongly curved as in Orthis romingeri, and in most cases not curved at all; (h) inthe dorsal valve, which in the present species is more strongly arched with a moredecided sinus; (c) in the sculptiare, inasmuch as the ribs are narrower, sharper,fewer in number, and separated by wider interspaces than in Orthis romingeri Barr.This species, eminently characteristic of the lower conglomerate zone of theKamenna hurka near Teji^ovic, was found in thousands of specimens (impressionsand internal casts) at the locality mentioned, in conglomerate-like, quartzitic sand-stone and in the greywacke intercalations. I vsaw the species in similar rock fromGross Lohovic southwest of Skrej. (Collection of the Bohemian University atPrague.
)
Proc. N. M. vol. xxviii?04 17
254 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.Ohseriyiflo'iis.?In the material of this species Doctor Pompeckjsent me, there is one cast of a ventral valve that shows that a convexdeltidium covered about two-thirds of the delthyrium; its front mar-gin was arched so as to leave considerable space open between it andthe place of the hinge line.There is a decided mesial sinus in most specimens of the dorsal valve,but in some it is flattened so as to scarcely break the uniform low con-vexity of the valve; the strength of the mesial elevation of the ventralvalve also varies from a marked ridge to a flattened median space.The species appears to l)e quite distinct from any described Cam-brian form.Form atlov and local Itie.s.?Lower Cambrian sandstone of lower con-glomerate zone. Localities in Bohemia as mentioned above.NISUSIA (JAMESELLA) PERPASTA Pompeckj.Orthis perpasta Pompei'K.j, Jahrliuch k. k. geol. Reichsanstalt, XLV, 1896, p.515, pi. XV, figs. 15-18.Original description.?Outline subrectangular, with straight hinge line and slightlybent frontal margin; cardinal angles slightly drawn in; the length is little more thanhalf the breadth, the greatest breadth being in the middle of the valves. Both valvesare very strongly arched.The ventral valve has a high, steep area, with a large, triangular foramen, and theareal edges are rather sharp. The apex is not drawn forward beyond the hingeline. From the apex to the frontal edge there is a sinus which gradually increasesto a considerable breadth. The dorsal valve, which is also strongly arched, has avery low and indistinct area, with a low, broadly triangular foramen. On thefrontal margin a strong, broad swelling of the edge of the valve corresponds to thesinus of the ventral valve.Judging by some internal casts and impressions, the shell is ornamented withsome 40 broad ribs, of which about half are inserted between the primary ribs atvarious distances from the apex. Concentric lines of growth cross the ribs. On thetop of the shells, along some of those lines of growth (1 or 2) the sections of theshell are found to be imbricated; near the frontal edge such imbrication is presentmore frequently in very short intervals.Orthis perpasta differs from Orthis Kuthani by its greater breadth, by the almostuniform and much stronger arching of both valves, and also by the fact that in theformer species the ventral valve bears a sinus, while in Orthis Kuthani the sinus is onthe dorsal valve.About 30 internal casts and impressions of dorsal and ventral valves were found inthe conglomerate-like, quartzitic sandstone, and more rarely in the greywacke sand-stone of the lower conglomerate zone on the "Kamennd hurka" near Tejfovic.Ohservations.?Doctor Pompeckj very kindly sent me several frag-ments of sandstone containing casts of the interior and exterior of thevalves. The specimens illustrated by Doctor Pompeckj are smootherthan most of those sent to me, but the description corresponds to theribbed specimens, and a few nearly smooth interior casts occur in asso-ciation with the more strongly ril)})ed shells. The convexity of theventral valve is quite variable but is usually considerable. One of the
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 255marked charactei's of the dorsal valve is the hirge transverse space
?
pseiidocruraliuni?beneath the umbo. In one example it is crossed ver-tically by the main vascular sinuses. What may be a trace of a low,simple, rounded cardinal process is shown in one cast. The crura werestrong, with small dental sockets beside them.X. {J. ) perpasta resembles Nisuxki alherta in form and convexity,but it does not have a spinose surface.Formation and locality.? \jO\iQY Cambrian. Quartzitic sandstoneof the "Skrejband." Kamenna hurka near Tejfovic; also Skrej(Slapnicky) Bohemia.NISUSIA (JAMESELLA) PERPASTA MACRA Pompeckj.Orihis perpasta macra Pompeck.f, Jahrbuch k. k. geoly^eichsanstalt, XLV, 1896,p. 516, pi. XV, fig. 14. y^Original description.?Some internal toasts and iijtpressions of dorsal valves agree inoutline perfectly with the dorsal valves of OrtJiis perpasta, but differ from the typeform by much less arching and ribs farther apart.Occurs in the same localities as Orthis perpasta.Oh.^crvatkms.?The gradual increase in the width of the interspacesbetween the ribs, from a very narrow space to several times the widthof the rib, makes this variety of doubtful value.NISUSIA (JAMESELLA) PERPASTA SUBQUADRATA Pompeckj.Orthis perpasta var. subquadrata Pompeck.i, Jahrbuch k. k. geol. Reichsanstalt,XLV, 1896, p. 516, pi. xv, figs. 19, 20.Original description.?As compared with the type form, this variety is distinguishedby less breadth, the length being to the breadth as 3 to 4. The anterior angles ofthe straight hinge edge are drawn in somewhat more than in Orthis perpasta f. typ.The ventral valve is higher, with higher and steep area, pierced by a large triangularforamen. The sinus, which extends from the high vertical apex to the frontal edge,is bordered by obtusely rounded edges. Dorsal valve proportionally more bulgedthan in the type form. Sculpture as in Orthis perpasta i. typ.The outer form strikingly recalls Orthisinae; but the pseudodeltidium, the medianseptum, and the spondylium of the ventral valve are lacking.Orthis perpasta var. subquadrata was found in several internal casts and impressions,together with Orthis perpasta f. typ., more rarely in greywacke sandstone than inthe conglomerate-like, quartzitic sandstone.Obser'oations.?This variety apparently is not constant, as ventralvalves occur in the material before me that have the subquadrate formwith relatively less convexity than the convex forms of the speciesper])a8ta. NISUSIA (JAMESELLA) UTAHENSIS, new species.Ventral valve transverse, strongly convex; most elevated at theumbo, which is surmounted by the upward pointing apex at the edgeof the area; area slightly inclined forward from the hinge line; delthy-rium large and covered by a convex deltidium. Surface marked by
25() PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
several strong-, rounded ribs irregularly alternating with smaller ribs;fine, radiating strife occur on the ribs and interspaces.Only two specimens of somewhat imperfect ventral valves are knownof this species. The description is of the best preserved specimen.The second specimen has a greater lumiber of more regular rilis thatincrease by interpolation of short rilxs. One specimen has a width of8 nmi. and a length of -1.5 mm. from the apex to the front margin,which is about the distance from hinge line to front margin.The nearest related species is Wlsusla alherta^ from which it differsin surface ribs, forward inclination of the area, and prominent convexdeltidium.Formation and locality.?Middle Cambrian. Limestone about 50feet above top of upper greenish shales, Rock Canyon, back of Provo,Utah. NISUSIA (JAMESELLA), species undeterminedThisdoul)tful species is l)ased on an interior cast of a liroken ventralvalve. The width of the shell is 15 mm., and length 8 mm., with apexbroken off'. A broad, shallow sinus arches the frontal margin, andnarrows toward the umbo. Radiating ribs narrow, about 5 in a spaceof 2 mm.Formation and locality.?Lower Cambrian. Pinkish-colored lime-stone of Olenellus zone, coast of Labrador on Straits of Belle Isle.EOSTROPHOMENA, new subgenus of STROPHOMENA.The description of the type species gives all that is known of thesubgenus. It differs from Strophomena in having the cardinal processin the dorsal valve merged into a ridge formed by the extension of thecrural plates along the posterior margin, so as to cover the delthyriumand unite at the median line.Type.? Strojdioinena {Fontrophomen a) elegantala.^ new species.Ohscrvations.?The cardinal process is more like that of Orthothetesthan that of Strophomena; it differs from both in being more simplein its construction. It is probable that there is a group of shells hav-ing the characters of *S'. [E.) elcyantula., but owing to the difficulty ofobtaining interiors of the valves, it is impossible to designate them.Strojdwniena auro7'a Billings" is one of these; also Leptxna decipiens.^STROPHOMENA (EOSTROPHOMENA) ELEGANTULA, new species.(xeneral form transversely sul)semicircular or subelliptical, greatestwidth at the straight hinge line. Surface concavo-convex, and markedt)V tin(% radiating, even stria% separated into flat bands b}^ strongerand mor(^ prominent stria> oi- ribs; fine concentric strife, and more orless prominent lines of growth cross the radiating strire. The ventral
"Pal. Foss., I, p. 218. ''Idem., p. 74.
NO. 1395. CAMBRIAN BRACHIOPOBA? WALCOTT. 257
valve is .slightly convex, with h>\v umbo iuul small, incurved apex. Thedorsal valve is tiatteiicd in th<' uinbonal region and concave toward themargins; the interior shows a narrow, rounded median furrow, alsorounded crural plates that unite with the cardinal process to form acontiiuious ridge covering the anterior portion of the delthjn-ium; thedental sockets appear to have been relatively large and deep: theadductor muscle scars are a little to the front.A ventral valve 6 mm. wide has a length of -i mm., and a dorsalvalve 5.5 mm. wide is 3 mm. in length.Ohse7'vatio))i<.?The concavo-convex valves and the ridge represent-ing the cardinal process place this little shell with the Strophomenoidforms, but as no described genus possesses the characters shown, asubgenus of Sirophoinenn is made to receive it.Fortiiation and locality.?Upper Cambrian. Ceratopyge limestoneassociated with Plectorthix daunu^, Oland, Borgholm, Sweden.ORTHIS DalmanSubgenus PLECTORTHIS Hall and Clarke.Plectorilm Hall and Clarke, Pal. N. Y., VIII, 1892, Pt. 1, p. 194.In their subdivision of the genus OrtJiis Dalman, Messrs. Hall andClarke restricted the genus Ortliis to the group of which Orthis cal-lactis Dalman is the type, and, among American forms, Ortliis trice-nar'ta of the Trenton and Hudson faunas. These forms show theexistence of a transverse apical plate in the delthyrium of the pediclevalve. A second group was placed under the name of Plectorthisand called the group of Orthis plicatella^ and of this the authors sav:This i.s a persistent form, which in American faunas, so far as known, is limitedto the Trenton and Hudson River formations. While it retains the strong externalribs of the typical Orthis, these are not invariably simple ( O. fisslcosla, Hall; 0. irip-llcatelld, Meek; 0. xquivalvis, Hall, not Davidson; 0. JamesI, Hall); the cardinal areaof the pedical-valve is comparatively low and the valves are subequally convex. Inthe interior the character of the muscular scars, dental lamellae and cardinal procesais essentially the same as in Group 1 (Orthis), and the minute structure of the shellappears to be in precise agreement with that of 0. caUigramma, though no evidenceof tubulose costae has been observed. In Orithis Jamesi, which is placed in thisassociation, there is occasionally a deviation toward the resupinate contour exempli-fied in the Oroups IV {Orthis subquadrata) and V {Orthis sinuata).In the Cambrian faunas 1 find a group of species intermediatebetween the typical forms of B/'llmgsella and of Orthis, as limited byHall and Clarke, which appear to belong to the subgenus Plectorthis.This Cambrian group of shells may be defined as follows, the type ofthe subgenus being OrtJiis j^licatella^?i\\., audits Cambrian represent-ative, Orthis 7'emnicha Winchell:Diagnosis.?Shells subquadrate to transversely elongate; with orwithout median fold and sinus; valves subequally convex. Hingeline straight, usually forming nearly the greatest diameter of the
258 PROCEEDINflS OF THE NATIONAL MUSEUM. vol. xxviii.
shell. (-ardiiKil oxtreniitios broadly ano-ular, rarely acuminate. Sui-face with radiatiiii;' ribs iitid stria' which may be crossed by concentricj,^rowth lines and stria-. The ribs increase as the shell grows, byinterpolation.The ventral valve has the umbo more or less elevated over the hingeline, the apex acute and usually incurved. The area is rather broad,tiat or incurved and transversely striated. Teeth short and supportedby dental plates that extend to the ])ottom of the valve, bounding aspace (pseudospondylium) including the main vascular sinuses andarea of attachment of the adductor muscle scars. Delthyrium open orpartially closed by a convex deltidium. The adductor muscle scarsare included within a narrow median area beneath the umbo on eachside of the median line, and the diductors in a more or less iiabelliformarea outside of the main vascular sinuses. Pedicle scars unknown.Dorsal valve with low umbo and slightly incurved apex; area welldeveloped with a broad delthyrium. Deltidial cavity with a straight,simple cardinal process. Dental sockets small with short crura. Theadductor muscle scars are small, the anterior being nearer the medianridge, which usually extends forward from the base of the cardinalprocess. Shell structure impunctate, and fibrous as far as known.Tyi)e of sahyeims.? OrtJih 'plicatella Hall.Ohservatioiis.?The Cambrian species referred to Plectoi'tliis haverelatively thin shells that retain on the interior surfaces but slighttraces of the muscle scars and vascular markings, except in theumbonal cavity.The geological range of this subgenus in the Cambrian rocks is fromthe upper portion of the Middle Cambrian through the Upper Cam-brian, and into the Ordovician, where it terminates in the HudsonRiver formation.Two of the species from strata referred to the Middle Cambrian arerepresented by material too imperfect for specific description; theyoccur with Paradoxides in Bohemia, and it is not improbable that theywill be found to belong to some other genus. P. retvojlexa Matthewoccurs in strata referred tentatively by Matthew to his Division E2 ofthe Cape Breton Cambrian section. He first referred the strata to theOrdovician. Of the remaining six species referred to Middle Cam-brian strata /"*. wlc/iitaensis occurs in the upper portion of the MiddleCambrian and base of the Upper Cambrian, and P. indianola alsooccurs in both Middle and Upper Cambrian.From the above statements it will be seen that the first representa-tives of Plectorthis in the Candjrian appear in the Middle Cambrian,and that the greater number of species, 14 out of 21, are Upper Cam-brian forms.
NO. 1395. CAMBRIAN BRACHTOPODA? WALCOTT. 259The species referred to the .subgenus are as follows:
Cambrian.M.
f atava Matthewvhrislianix KjerulfdauniDs, new speciesdesmopleitra Meekdesmopleura nympha, new varietydiablo, new speciesdoris, new speciesfiastingsensis, new speciesiddingsi, new speciesindianola, new speciesjohannensis Matthewkayseri, new speciesUrinarssoni, new speciesnewtonensis Wellerpagoda, new speciespapias, new speciesremnicha Winchellremnicha sulcata, new varietyremnicha texana, new varietyremnicha winfieldensis, new varietyretroflexa Matthewsaltensis Kaysertidlbergi, new species 1 iurichitaensis, new species ! j xivichitaensis laeviusculus, new variety - xwimani, new species !2 species undeterminedPLECTORTHIS? ATAVA Matthew.Slrnphomena atava Matthew, Trans. Roy. Soc. Canada, X, 1898, p. 102, pi.VII, fig. 8a-f.Rafinesquina ? akiva Schuchert, Bull. U. S. Geol. Sur. No. 87, 1897, p. 338.Description by Doctor Matthew.?Narrowly semicircular. Valves slightly arched,rather wider than the hinge line, compressed at the cardinal angles; sides of thevalves nearly straight behind, regularly rounded in front.Ventral valve moderately convex, highest and somewhat angulated at the middleof its length; umbo inconspicuous and appressed to the very narrow area.Dorsal valve somewhat concave, especially toward the umbo, which is depressedto the general level of the valve.The interior of the ventral valve has characters intermediate between those ofOrthis and Strophomena. The ridges inclosing the cardinal muscles are shorter andcloser at their extremities than in Strophomena, and the scar of the adductor muscleis broader and shorter, but extends half way to the front of the valve. There is alow sharp ridge at the umbo, between the branches of the posterior cardinal nmscle,and the ventral cavity is faintly outlined in front. Another cast of the ventral valveof a larger individual, perhaps of this species, shows the impressions of the musclesmore distinctly; in this the impression of the adductor muscle is much nearer to thehinge, being about two-thirds from the front of the valve; there is a low callus infront of the imprint of the adductor muscle.A partly decorticated example of the dorsal valve exhibits a small bifid scar at thehinge line, due to the adductor muscle. There is no median ridge, such as is foundin Orthis, the median sinus being almost obsolete. In front of the impression of theadductor muscle is a small, low callus.Sculpture.?This consists of sharply raised, rounded, radiating ridges, slightlycrenulated by obscure, transverse lines. These ribs are of varying size, every thirdor fifth rib being larger than the others; these large ribs extend outward from theumbo, and the smaller ones are intercalated between them, or spring from them.On the dorsal valve there are two main ribs in the sinus of the valve and three others
260 PROCEEDING'S OF THE NATIONAL MUSEUM. vol. xxvin.extending to the luteral niar<riiis; .-lualler ribs are intercalated l^etwecn these. Oneach wide of tiic jinmii of ril)s on tlie niiddle third of the i^hell are four fainter, hntmore strongly an:hed groups of ridges, wiiicii throw off minor ridges at the l)ack,directed toward tiie lateral margins. On the ventral valve the small ribs are almostall inter<'alated and ilo not spring from the back of the i^rimary ribs, as in those ofthe dorsal valve.Size: Length, 12 mm.; width, 14 mm.; height of area of dorsal valve, 2 mm., ofventral valve, 1 mm. A valve sujiposed to be of this species is 15 mm. long and 19mm. wide.Horizon and lucaUty.?In dark shales of division ;^a, at Navy Island.Obseroptions.?With the available data this species appears to bequite as near to Plectorthis as to an}' described genus. It does notappear to belong with tlie typical forms of Stropliomena or Rafines-quhui. The surface ribs, increasing by interpolation, and possiblyl>ifurcation, and form of the pseudospondylium in the ventral valve,strongly suggest relationship with PUctorthis. It will probablyrequire better preserved material to satisfactorily determine the cor-rect generic reference for the species.Foriiiation and locality.?Upper Cambrian. Division 3a of Matthewsection, St. John terrane, Navy Island, St. John Har))or, New Bruns-wick. PLECTORTHIS CHRISTIANIiE Kjerulf.
Ortltis cJiristianiir K.ieri'lf, Veiviser ved. geol. Exk, i Christiania, 1865, pp. 1,.3,tigs. 8a, b, c.Ortlus cJiristiaiiiir Brogger, Die Sil. Etagen 2 nnd H, 1882, p. 4S, pi. x, figs. 14a,b, c.OrtJm christianiir Gagel, Physik. Oekon, Gesellschaft-Konigsberg. Brach. Camb.und Sil. Diluvium Ost uud Westpreussen, 1890, p. 84, pi. 11, figs. 22a, 22b.Ortlm chrislkmix Pompeckj, Neues Jahrbuch, Min. Geol. und Pal., I, 1902,Tremadoc der Mont. Noire, p. 7.This shell appears to differ from an}^ described species by the pecul-iarity of the bifurcation of the radiating ribs. In all the species Ihave referred to Plectortlds the increase in the number of ribs is byinterpolation and not by true bifurcation. In O. christianim theincrease is by both methods. The reference to Plectorthh is some-what doubtful, as there is not sufficient data to base a reference on thecharacters of the interior, cardinal areas, or convexity of the valves.I have received a large number of specimens from Norway andSweden lal^eled (Jrthis cJiristianice. After a study of all availablematerial only the shells from the argillaceous shale of Russelokken,Norwa3\ and Oiand, Borgholm, Sweden, appear to belong to thespecies. The shells in the Ceratopyge limestone {O. daunua) haveribs that incirease in number by interpolation of ribs in the interspacesbetween the older ribs, and a second species {P. wiinani) that occursin both the shale and limestone has simple ribs with few interpolatedbeyond the umbo. Another transverse form has simple strong ribsthat increase in numlxM- by interpolation of a few new ribs.
NO. 1395. CAMBRTAN BRACHTOPODA?WALCOTT. 261Doctor Bro^ger's illustration of this species suiigests (). (hnniu.smore than the typical form of <K chriMUiuin'^ as 1 understand undinterpret it. "C/yVA/.s 7>^^/vvr' Dsdman, has sometimes been referredto O. cliristlaniice.Dr. Curt Gagel described the form usual 1}^ found in the limestone,stating that the surface is covered with strong dichotomous ribs. Hefound it in drift blocks of the Ceratop\'ge limestone near Belschwitz,also in glauconitic limestone near Preussinch, Holland, and Weblau.'*Dr. Ferdinand Roemer calls attention in his description of the driftin the North German plain to the fact that Remele was the first toidentify with certainty blocks of the Ceratopyge limestone of Swedenin the drift, the presence of a form like OHhis christianlm being partof the evidence.^ This shell was probably Pledortlik dwrnms. DoctorRoemer states in his description of the Ceratopyge limestone that asmall Orthis {lOrthis christianize) predominates.Foviiiatlon and locality.?Upper Cambrian. Ceratopyge shale,Russelokken, Christiania, Norway. Borgholm, Oland, Sweden.PLECTORTHIS DAUNUS, new species.This species differs from (J. r/wistianlse by having simple ribs thatincrease in number toward the front and lateral margins of the shellby interpolation of new ribs; no true bifurcation of the ribs wasobserved, A strong median sinus occurs on specimens of the dorsalvalve in both shale and limestone. The shell is fibrous and impunctate.No traces have been seen of the fine, rounded, radiating striaj thatoccur on the broader ribs and interspaces of P. cJuidlanise. Thisspecies differs from P. wvinanl by its more transverse form and lesssimple ribbing of the shell.Formation and locality.?Upper Cambrian. Ceratopyge limestone,Toren, Christiania; Slemenestad west of Christiania, Norwa^^ Oland,Borgholm, Sweden.PLECTORTHIS DESMOPLEURA Meek.Orthis coloradoensis Meek (not Shumard), Proc. Amer. Phil. Soc, fl, 1870,p. 425.Orthis desmopleura Meek, U. S. Geol. Sur. Wyoming, Hayden, 1872, p. 295.This shell has the general form and external characters of O. wichi-taensis. It differs in being less convex and in the details of the radi-ating ribs. 0. desmopleura differs from O. remnicha in its uniformlysmaller size, less convexity, and in the details of the radiating ribs.The ribs have a wide range of variation, but when from the samecharacter of matrix they are all of the same type, and the shells gradefrom one to the other.
"Bracfi. Camb. nnd Sil. Geschiebe in Diluvium Prov. Ostund Westpreussen, p. 34.t>Lethea Erratica in Pal. Abbordl., II, Pt. 5, 1885, p. 36.
262 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.Nothino- is known of the intciior of the valves beyond an imperfectcast of the area, of a dorsal valve. Ortliis /i(niil>fi)'gh<ni<l!< Walcott" isa closel}' rehited species and it may be identical.Formation and locality.?Upper Cambi-ian to Lower Ordovician.The Upper C-amln-ian locality is on Wolf Creek, 15 miles west-south-west of Sheridan, Wyoming-, on the eastern slope of the Big- HornMountains.The type specimens are from near the base of the Ordovician rocksat Glen Eyre, canyon of Camp Creek, near Colorado City. The specieshas also been found on west side of Front Creek, below Beyer Park,Colorado.PLECTORTHIS DESMOPLEURA NYMPHA, new variety.This variety is based on sti'onj^l}^ convex ventral valves in which thesurface is marked by tine, radiating striae, separated into bands of 3 to6 striae by stronger and more elevated stria?; concentric lines and oftenridges of growth occur that on some shells give an imbricated appear-ance to the shell beyond the umbo.Formation and locality.?In passage beds between the Upper Cam-brian and Ordovician, on north side of Tepee Creek, Big HornMountains, Wyoming.PLECTORTHIS DIABLO, new species.This species is founded on a small, transverse shell that is markedby a few prominent radiating cost;? that extend from the umbo to themargin of the shell. In the cast the costa? have a sharp smimiit andslope evenly to a narrow space between them.A ventral valve 9 mm. in height has a width of 14 mm., which isabout the average proportion of the specimens in the collection. Thecasts of the ventral valve show a rather low area divided by a delthy-rium, the inner angles of which have a rather strong tooth on eachside. The dental plates extend backward farther than in most speciesof the genus, becoming attached to the bottom of the valve only nearthe teeth, and not extending forward as in P. remnicha to form apseudospondylium. None of the specimens in the half dozen shells inthe collection show the muscular or vascular markings. There mayor may not be a mesial depression on either valve.Formation and locality.-?Upper Cambrian. St. Croix sandstone ofTrempealeau, Wisconsin.PLECTORTHIS DORIS, new species.Of this species a ventral and dorsal valve occur in the collection.The general form is rounded subquadrangular. The ventral valve isstrongly convex with the greatest height at the umbo, from which the
?Mong. VIII, U. 8. Oeol. Surv., 1884, p. 73, pi ii, figs. 5, 5a.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 263beak arches over a hio-h, ))ackward inolinini^- area. Tho dorsal valve ismuch like the ventral iu form, except that it is h^s.s convex and lesselevated at the area. Surface of both valves with numerous radiating-ribs that have an angular summit and an angular depression betweenthem. The ribs increase in number toward the front by interpola-tion. The ventral valve has a length of 7 mm. ; width S mm. Thedorsal valve is a little shorter than the ventral.This shell is not unlike FltcioTthk indimiola in form and surfacecharacters. It difters in being more convex and in the absence of asinus or median fold on either valve.Formation and locality.?Middle Cambrian. Chang Hsia limestone.Two and three-quarters miles southwest of Yen Chuang, Shantung,China.Collection of Mr. Eliot Blackwelder, Carnegie Institution Expedi-tion to China.PLECTORTHIS HASTINGSENSIS, new species.Shell transversely subelliptical. Surface with numerous strong,rounded, radiating ribs increasing in number by interpolation. Theribs appear to be broader and with narrower interspaces on the ventralvalve; concentric ridges and tine strise of growth are a marked featureof the surface. A ventral valve 4 mm. in length has a width of mm.;a dorsal valve 6 mm. long is 10 mm. in width.Ventral valve strongly convex, most elevated on the umbo, andwithout mesial fold; apex incurved slightly over the delthyrium areawell defined, and divided midway by a large delthyrium, it is inclinedbut little from the vertical.Dorsal valve slightly convex in young shell-^, and becoming more soas they increase iu size; area low and inclined backward over the hingeline.Ohservations.?This species is unlike other described forms in thecharacter of its ribs, with the exception of Plectorthis johaiuiensis^which it resembles very closely. Doctor Matthew describes the latterspecies as having a very thin shell, and it is found in the Upper Cam-brian at St. John. No interior features have been seen. Dr. G. F.Matthew mentions having found fragments of Protorthis or Orthis inthe phosphate nodules at Hastings Cove, too imperfect for description.^'Formation and locality.?Middle Cambrian. Upper Paradoxideszone. Hastings Cove, Kennebecasis River, at base of Paradoxideszone, Hanford Brook, in limestone and superjacent shale, St. JohnCounty, New Brunswick.
"Trans. Roy. Soc. Canada, 2d ser., Ill, 1897, p. 180.
'2(>4 VUOCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.PLECTORTHIS IDDINGSI, new species.General form and convexity much like that of yome varieties of P.ifullanola. Its surface characters also approach those of the moreregularly ribbed shells of the latter species. The principal diti'erenceis in the less convi'xit}', lower um])o, and lower area of /*. nldrngs'i.
'I'he interior of the ventral valve shows a short, well-defined umbonalcavitv, with a strong- vascular sinus on each side of it that extends wellforward into the valve.The species is named after Prof. Joseph P. Iddings of the University of Chicago, formerly of the U. S. Geological Survey, who col-lected the specimen.Fo I'Illation and locality.?Upper Cam))rian. Gallatin terrane, southside of Gallatin Valley, Yellowstone National Park, Wyoming.PLECTORTHIS INDIANOLA, new species.
vShell small, transverse, with the cardinal extremities rounded, angu-lar, and in some specimens almost alate. Valves moderatel} convex,the ventral nearly twice as much so as the dorsal; the hinge line Aariesin length from slightly less than the greatest width of the shell towhere, in the shells with extended cardinal extremities, it is one-tifthgreater than the width of the shell across the center.The ventral valve may or may not have a mesial depression. Insome examples the depression is broad and rounded, and in others itis shallow with stronger ribs at each margin; umbo somewhat elevated,and curving over toward the hinge line, beyond which it projects, ter-minating in a small, incurved beak; dorsal valve considerably lessconvex than the ventral; beak small and projecting slightl3^ over thehinge line. The median sinus in the dorsal valve varies from a broad,shallow depression to a narrow, rather deep furrow that gives abilobed appearance to the valve.The surface is quite variable in the strength and arrangement of thestrong and minor radiating elevated ribs and striae. On some shellsthe}^ are very tine and of nearly equal size, separated by grooves ofabout the same width as the ribs or striae. In other examples everythird or more widtdy separated rib is stronger and elevated above amore or less broad interspace marked by line ribs or costte.Almost nothing is known of the interior of the valves. A fewspecimens show a well-marked umbonal cavity beneath the umbo thatis nmch like that of O. renin icha. The area of the ventral valve isinclined backward at an angle of about 65? to the plane of the marginof the valve. It is rather low and broken midway by a strong delthy-rium. The area of the dorsal valve is low and inclined well out overthe hinge line.Ohservations.?Plectorthis indianola is almost as variable in its formand surface markings as P. wichitaensis^ with which it is associated ata luuiibcr of localities. It differs from the latter in the bilobed dor-
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 265
sul valve, more strongly incurved umbo and apex of the ventral valve,and the general appearance of convexity and rotundity of the ventralvalve. When the specimens of the two species are imperfect, or theyoiuig shells of /?*. luicJutaensis occur in association with the shells ofP. indianola it is difficult to determine positively to which species the}'belong.Formation and locality.?Upper Cam})rian. Top of Reagan forma-tion, west side of Honey Creek, near SE. corner sec. ;^5, T. 1 S.,R. IE., Ardmore quadrangle, , northwest extremity of ArbucklcMountains, al)Out 4 miles east of Homer. Indian Territory, Reagangveensand, two-thirds of a mile east of Canyon Creek, 15 miles north-west of Fort Sill, SE. i NE. i sec. 2, T. 4 N., R. 13 AV., WichitaMountains, Oklahoma Territory.Middle Cambrian. Reagan Formation, SW. i sec. 17, T. 4 N., R.12 W., Wichita Mountains, 11 miles northwest of Fort Sill, Okla-homa Territor3^ Potosi limestone, near Potosi, Missouri. Limestoneon Cold Creek, north end of gorge, opposite north end of SpongeMountain, Llano County, Texas.PLECTORTHIS JOHANNENSIS Matthew.Orthmna (?) johannenm Matthew, 1891, Trans. Roy. Soc. Can., IX, 1891, p.49, pi. XXII, figs. i;^a-c.Origwal description.?Shell subquadrate, doubly convex, rather flat, very thin.Dorsal valve depressed at the sides and front, and having a broad, shallow mediansinus. The valve is about one-quarter wider than long, and the hinge line is nearlyas long as the length of the shell. Umbo slightly elevated, hinge plate weak and thin.Ventral valve depressed at the sides, and having a few median ridges running fromthe umbo to the front of the shell. This valve is somewhat geniculated at two-fifthsof its length from the umbo, and from the bend faintly raised ridges diverge to theanterior angles of the shell; behind the geniculation the surface of the shell is markedl?y faint undulations similar to those of Strophb)i)ena rJinmboidalis.The umbo is not prominent, but the back of the valve is regularly curved and thearea rather low.Sculpture.?Closely set strife radiating fr(nii tiie umbo and faint concentric stripemark the shell.Size.?Length of the ventral valve, 9 mm. ; width, 10 mm. Length of dorsal, 8mm. ; width, 10 mm.Horizon and locality.?[Upper Cambrian C. D. W.] Limestone lentilles in theblack shales of division .'^a, Germaine street, St. John.This species has a low umbo for an fh'thisina, and in its form recalls the genusSlrophoiuena, as also do the concentric undulations that are found on the back of theventral valve. The dorsal valve, however, is convex, and the area of this and theventral valve too high for a Strophomena. It does not appear to agree with anydescribed species of Orthisina. It resembles 0. orientalis White, somewhat in form,t)ut is not so long nor so wide at the hinge. From 0. pepina Hall, it differs in itslower umbo and area, shorter hinge, and smoother surface. It approaches moreclosely to the form from the Potsdam sandstone of the West, figured by ProfessorHall, l)ut not named, except as a Strophoinnia or StropJiodonta." <(
"Preliminary Notice of the Fauna of the Potsdam Sandstone. Sixteenth Rep.N. Y. State Cab. Nat. Hist., pi. vi, fig. 22.
266 I'ROCEEDINaS OF THE NATIONAL MUSEUM. vol. xxviii.Doctor Matthew very kindly sent me the types of this species.There is little that can he added to his very complete description. Asfar as known, the characters of the shell are those of the group ofspecies referred to, Plectorthix.PLECTORTHIS KAYSERI, new species.This is a larger shell than PlectortluH Ihiiiwrsmiu^ with which it isassociated. Its surface is marked by numerous line radiating stria?, 4to 5 in a distan(;e of 1 mm., and the inner layers of the shell appear tobe minutely punctate. The ventral valve is more convex than thedorsal, the latter being nearly flat in young- shells. Nothing is knownof the interior except one cast of the pseudospondylium of the dorsalvalve, which is larger in proportion than that of P. Unnarmoni.The largest ventral valve has a length of 14 mm.; width, 20 mm.This species belongs in the group of Plectorthis represented byP. desniojjleura and P. UnnarssonLThe species is named after Dr. Emanuel Kayser.Formation and locality.?Upper Cambrian. Lower part of ChaoMi Tien (?) limestone, 2.7 miles southwest of Yen Chuang, andChao Mi Tien, Province of Shantung, China. Collected by EliotBlackwelder and Bailey Willis of the Carnegie Institution Expedi-tion, 1903. PLECTORTHIS LINNARSSONI Kayser.Orthls Ihvnarxsoiii Kayser, Cambrische Brach., von Liau-Tung, China, Rich-thofen, IV, 1883, p. 34, pi. iii, fig. 1.Original description.?Shell seniielliptic in outline, broader than long, with hingeedge straight, corresponding to the greatest breadth of the shell. Large [ventral]valve moderately convex. Small [dorsal] valve slightly arched, with a sinus devel-oping already at the umbo, and growing quite broad and deep toward the edge.Umbo of ventral valve small, area very low. Surface of shell covered with rathersharp ribs, very variable in strength, separated by narrow furrows. By reason ofrepeated splitting, beginning close to the umbo, the ribs appear rather as bundles ofribs. On the matrix these bundles appear as broad, obtuse-angled folds, which,owing to repeated marginal splitting in even a higher degree than on the shellitself, appear as bundles of ribs of very unlike strength. When the surface is wellpreserved, a delicate concentric growth striation is perceptible.Doctor Kayser compares this shell with Orthh hicksi Salter, and(). exporecta Linnar.^son, on account of the surface characters. It doesnot appear to be very closely related to either species, but it is inmany respects allied to Plectorthis desmople^ira2indL P. wicldtaensls. P.Unnarssoni differs from both in being more transverse.Formation and locaUty.?Middle Cambrian. Lower part of Chao MiTien (?) limestone, 2.7 miles southwest of Yen Chuang, Province ofShantung, China. Collected by Eliot Blackwelder and Bailey Willis,of the Carnegie Institution Expedition, 1903.
NO. 1395. CAMBRIAN BRACHIOPODA-WALCOTT. 267PLECTORTHIS NEWTONENSIS Weller.Orthix iiewtonenm WEhhER, Geol. Sur. New Jersey, Pal., Ill, l!t03. Pal. Faunas,p. 113, pi. I, figs. 3-5.This little shell occurs in the form of casts in a sandstone that is toocoarse to preserve the details of the outer surface. The cast of theinterior shows tine, simple, radiating ribs that increase by interpola-tion and that are coarser on the ventral than on the dorsal valve.Ventral valve slightly flattened at the front; dorsal valve with a broadmesial sinus. The shell appears to have been thin. The cast of thepseudospondylium of the ventral valve shows it to have been clearlydefined; the area is low and not sharply defined from the curve of thecardinal margin; it is nearly vertical to the plane of the margin of thevalve. The cast of the area beneath the umbo in the dorsal valve ismore triangular and less transverse than usually occurs; unfortunatelythe material is too imperfect to determine any details.This species is the eastern representative in the Upper Cam])rian ofPlectorthis indianola and Iddingsi. As far as can be determined bythe material available for comparison, it is closely related to them, butit is not probable that they are specifically identical.Ffyrmation and locality.?Upper Cambrian sandstone, Hardyston(|uartzite of Weller, Newton, New Jersey.PLECTORTHIS PAGODA, new species.Shell transverse, subsemicircular; a ventral valve 11 mm. in lengthhas a width of 15 mm., and a dorsal valve 8 mm. in length has awidth of 13 mm. ; hinge line a little shorter than the greatest width ofthe shell; cardinal angles vary from 75? to 111*^; valves moderatelyconvex. Cardinal area narrow in both valves and inclined backwardfrom the hinge line. Surface marked by equidistant, narrow, lowribs, 3 in a space of 2 mm. near the front margin of a shell 1(1 mm.long, with fine, radiating stria? between them; the radiating ribs andstriffi are crossed by fine, concentric stria?, and lines of growth.Ventral valve with a strong, somewhat angular, median fold, risingfrom a well defined depression on each side of it, or it might bedesignated as a very sti"ong rib rising above the general surface ofthe valve from a broad, median depression: the lateral slopes aregently convex. Dorsal valve with a strong, angular, median depres-sion, beginning at the posterior margin and gradually widening to thefront; the sides of the depression rise above the general surface of thevalve, and form with the outer sloyje a well defined, low ridge on eachside that extends a little forward on the front margin to fit into thedepressions on each side of the median fold of the ventral valve.The interior of a small dorsal valve has a broad, strong median ridgecorresponding to the depression on the exterior surface; a main vascular
268 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
.sinus starts on each side of the base of the median ridge and archesoutward and then forward al)out a depressed oval space on each side oftiie ridg-e; Uiteral l)ranches extend from the main sinus toward thesides; the impressions of the anterior and posterior adductor musclescars occur on the slopes of the median ridge and the oval depressions;somewhat obscure radiating lines mark the anterior portion of thesurface.<)hs.i'riHitioni<.?This shell is distinguished by its strongly markedmedian ridge on the ventral valve and sinus on the dorsal valve. Ingeneral form and surface markings it is not unlike Plectorthls desiuop-leura and Plectortlila vnchitaensts.Fwrnation <m(l locality.?Upper Cambrian. Chao Mi Tien lime-stone, two-thirds miles west and Pagoda Hill, one mile west-southwestof Tai An Fu, Shantung, China.Collection of Elliot Blackwelder, Carnegie Institution Expedition toChina. PLECTORTHIS PAPIAS, new species.This species is founded to receive a form represented by two smalldorsal valves from the Paradoxides zone of Newfoundland. They arcmoderately convex, with a low area divided by a broad delthyrium;surface marked by numerous, rounded, depressed ribs, crossed by con-centric strife and ridges of growth. Length of shell 4 mm. ; width,5 imn.Formation and locality.?Middle Cambrian. Paradoxides zone.Shales with Paradoxides davisi and 40 feet lower in the section.Manuels river. Conception Bay, Newfoundland.PLECTORTHIS REMNICHA Winchell.Orthis remnlclm N. H. \VI^x^ELL, Fourteenth Ann. Keii. Geol. Nat. Hist. Sur-vey Minnesota, 1886, \,. 317, pi. ii, fig. 7.Orthis f reiiinielia Walcott, Mong. XXXII, U. S. (leol. Survey, 1899, pp. 451,452, pi. Lxi, figp. 3, .Sa; pi. lxii, figs. 1, la-d.Shell of medium size, usually slightly transverse, with an ol^long,oval outline for the ventral valve, and a subquadrate to semicircularoutline for the dorsal valve. Valves moderately convex, with analmost straight hinge line that varies in length from nearly the great-est width of the shell to two-thirds the greatest width; cardinal anglesvarying from !H>-' or less in the extreme forms, with extremities some-what angular, to the other extreme, where they are very obtuse andhave the appearance of being almost rounded, their angle being notless than 120^, Cardinal area narrow, but well developed on eachvalve, and divided by a rather large delthj^rium.The ventral valve has in some specimens a shallow mesial depres-sion, and in some examples it is flattened toward the cardinal angles;beak small and curviiig down toward the hinge line, beyond which it
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 269projects slightly. Dorsal valve slightly less convex than the ventral;beak small, scarcely projecting beyond the hinge line.Surface marked b}'^ bifurcating, radiating costa?, that vary on shellsof similar size from 16 in the space of 5 mm. to 3 in the same space.This variation is shown in the specimens from Texas, Wisconsin, andWyoming. In well preserved specimens very fine, radiating, raisedstrise occur both on the costai and on the intervening depressions.These are shown on the casts of the shells from the St. Croix sand-stone of Winfield, Wisconsin, and on the larger shells from the lime-stones of Indian Territory and the Yellowstone National Park.The interior of the ventral valve shows a slightly raised, rathersmall tripartite umbonal cavity beneath the umbo, which is the onlytrace of interior markings of this valve observed. The interior of thedorsal valve has a slightly elevated area upon which occurs a narrow,short median septum. The crural plates are also well shown. Incasts of the interior from the St. Croix sandstone of Wisconsin thedental lamella? of the ventral valve are finely shown, and in the dorsalvalve the median septum and crural plates.This is one of the most variable shells that occur in the Cambrianfauna. Its range of variation is such in all of the widely separatedlocalites in which it occurs that one would scarcely hesitate, if in pos-session only of the extremes, to identify two well-marked species.The variation is not only in the radiating costse, but also in the gen-eral form of the shell. This variation is expressed in three varietiesthat receive names, and others might be designated if more minutevariations were given consideration.Formation and locality.?Upper Cambrian. St. Croix sandstone,Red Wing, Minnesota. Four miles north of Reedsburg and at Win-field, Wisconsin.Near base of Upper Cambrian, on ridge eight miles east of Yellow-stone River, three miles north-northeast of Mount Delano, Park County;Gallatin terrane. Crowfoot section, Gallatin Range, YellowstoneNational Park. It also occurs at a slightly lower horizon on the southside of the Gallatin Valley, and specimens were collected farther tothe north by Dr. A. C. Peale, opposite the mouth of Pass Creek, inthe Gallatin Valley, Montana.Upper division of Reagan formation, NW. i sec. 1, T. 2 S., R. 1 E.West side of Honey Creek, near SE. corner sec. 35, T. 1 S., R. 1 E.Ardmore quadrangle; northwest extremity of Arbuckle Mountains,about 4 miles east of Homer, Indian Territory.PLECTORTHIS REMNICHA SULCATA, new variety.This variety is founded on the strongly sulcate dorsal valve. Theventral valve shows only a slight flattening of the median portion.Formation and locality.?Upper Cambrian. St. Croix sandstone,Winfield, Taylors Falls, and four miles north of Reedsburg, Wisconsin.Proc. N. M. vol. xxviii?04 18
270 rROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.PLECTORTHIS REMNICHA TEXANA, new variety.The rounded, subquadrate form, and the arrangement of the radi-ating costs? servew to differentiate this variet}'. This costal vary con-siderably on different shells, but the tendency of the larger numberis toward a surface characterized by narrow, evenly spaced, radiatingribs; tine radiating striae occur on the ribs and interspaces. A shellthat is doubtfully referred to this variety occurs in the silicious MiddleCambrian limestones, 50 feet above the conglomerate series, St. FrancisCounty; also in section 22, township 35 of Iron County, Missouri.Forniation and locality.?Upper Cambrian. Cold Creek Canyon,Burnett County; on Cold Creek, north end of Sponge Mountain, 2miles south of San Saba County line in Llano county, Texas. Arbucklelimestone, NE. \ sec. 2, T. 2. S., R. 1 E., Ardmore quadrangle,Indian Territory.PLECTORTHIS REMNICHA WINFIELDENSIS, new variety.This variety is characterized by having tiner and more uniformcostte than any of the shells referred to /*. rcDinicJia. The costa?increase by interpolation rather than Infurcation in the true sense ofthe word. The shorter costa? begin as very narrow, sharp ridges,merging into the sides of the larger costte below the summit of thelatter, or they ma}' arise entirely on the interspaces between the costje.The pseudospondylium is less strongly developed than in P. remni-cha. The young shells are usually narrower at the hinge line than theadult; but this feature is sometimes present in large shells.Forniation and locality.?Upper Cambrian. St. Croix sandstone,Winiield, Pilot Knol), and doubtfully Trempealeau, Wisconsin.PLECTORTHIS RETROFLEXA Matthew.Oonambomtes -plana var. retroflexa de Verxeuil, Beitrage zur Geognosie desRussischen Reiches, 1830, p. 77, pi. xxv, figs. 1, 2.Clitambonites {Gonamhonites) plana var. retroflexa Matthew, Trans. Roy. Soc.Canada, 2d ser., I, 1896, p. 268, pi. ii, figs. la-c.Clitambonites planuK ntroflexns Schuchekt, Bull. U. 8. (Teol. Survey No. 87,1897, p. 184.Billingsella retroflexa iNIatthew, (ieol. .Sur. Canada, Rep. Cambrian Rocks, CapeBreton, 1903, p. 148, pi. x, ligs. 2a-e.This species is distinguished by the tine radiating costa? on the ven-tral valve and coarser cost;? on the dorsal. The tine, longitudinalstrife are similar to those of P. re/nnicha. In a specimen of the ven-tral valve, the pseud<)spond3dium, area, and base of the main vascularsinuses are shown. Specimens of the dorsal valve show the cast ofthe strong cardinal process, dental sockets, and crura, and the ovarianareas and visceral area between. Doctor Matthew describes otherfeatures of the interior of the valves.
N0.1395. CAMBRIAN BRACHIOPODA?WALCOTT. 271The character of the costpe and general features of this shell, as faras known, appear to class it with P. remniehd and allied forms.Formation and loeality.?Middle Cambrian. Sandstone and sandyshales, McFees Point, near George River station, Cape Breton, NovaScotia. PLECTORTHIS SALTENSIS Kayser.Ortkis saltensis Kayser, Pal?eontographica, Primord, and Sil. Foss. Argentinischen.Rep., 1876, p. 8, pi. i, fig. 16.Doctor Kayser\s description of the ligures lead me to refer this spe-cies to the genus Plectortlih. The general form of the valves, thecasts of the interior of the ventral valve,with the strong umbonal cavityand the radiating ribs, increasing in number by intercalation of newribs, appear to sustain the reference.Formation and locality.?Upper Cambrian. Sandstone of Salta andNevado de Castillo, and at Tilcuya, Argentine Repidjlic.Doctor Kayser also described and illustrated the dorsal valve of ashell that he referred to Ortlds sp. It suggests Ort/ii.s {(/rusia)lenticular Is. PLECTORTHIS TULLBERGI, new species.This shell occurs in the passage beds to th(? OrdoA'ician at the top ofthe Ceratopyge zone. Its transverse outline and simple, strong ribsserve to distinguish it from P. cliristianiw and P. daunus.The specific name is given in memory of Sven Axel Tullberg.Formation and locality.?Upper Cambrian. Ceratopyge zone,Olands, Borgholm, Sweden.PLECTORTHIS WICHITAENSIS, new species.In general form and outline this shell is related to P. desmopleuraand P. remnicha. It is more convex and ditl'erences in the radial rib-bing and striation separate it from the former species, and it occurs inan older geological formation. Its convexity and surface charactersdistinguish it from P. niimir/ui.A considerable number of relatively smooth shells occuis in the col-lections that may be designated as a variety, })ut it is often difficultto separate them from the more tinely ribbed specimens that arctypical of the species.Formation, and locality.?Upper part of Middle Cambrian and )jascof Upper Cambrian.Middle Cambrian, Reagan formation. A little soutli of W. \ of sec.2, T. 4 N., R. 13 W. One-quarter mile soutb of Canyon Creek Camp.15 miles northwest of Fort Sill, Wichita Mountains. Also in samearea near middle of west half of sec. 13, T. 4: N., R. 13 W.; 2 milessouth and 1 mile east of (knyon C!reek Camp; also in SW. \ sec. 17,4miles east of Canyon Creek Canip, 11 miles northwest of Fort Sill,
272 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvin.Oklahoma Territory. Cold Creek, north end of gorge opposite northend of Sponge Mountain, Llano Count3% Texas, Conglomerate seriesand 50 feet above, St. Francis County, Missouri. Upper Cambrian.Lower part of Arbuckle limestone. At small hill 2 miles southwest ofSignal Mountain, Wichita Mountains, Oklahoma Territory. Reaganformation, top beds, west side of Honey Creek near SE. corner sec.
;:55, T. 1 S. , R. 1 E. ; NW. i sec. 1, T. 2 S., R. 1 E., Ardmore quadrangle.Northwest extremity of Arbuckle Mountain, about 4 miles east ofHomer, Indian Territory.PLECTORTHIS WICHITAENSIS LAEVIUSCULUS, new variety.A variety with small, narrow, numerous ribs is given the abovename. Many graduations exist between it and the typical forms ofP. wichitae7iKlf<.Foniiafioii and lucaUty.?Same as P. iincldtaensli< in Oklahoma andIndian Territories.PLECTORTHIS WIMANI, new species.This shell is distinguished from /*. <-hri'<tl<uil^ >xn6. P. dmunis by therounded, narrow, simple ribs, less transverse and more rounded out-line. A ventral valve shows a well-defined pseudospondyliuni withthe tripartite division as seen in Plectortlih reinnifha. Two strongmain vascular sinuses extend forward from the lateral divisions of theumbonal cavity nearly to the front of the valve, corresponding inposition to those of the dorsal valve. The cast of the dorsal valveindicates the presence of rather strong crura, crural plates, teethsockets, and delthyrium.The ventral valve is rather strongly convex and dorsal valve aboutone-half as much so. The average size is 6 mm. to 7 mm. in diameter,the ventral valve being about 1..5 mm. larger than the dorsal. Thelargest ventral valve in the material available for study has a lengthof 9 mm.The species is named after Dr. Carl Winian in recognition of hisexcellent work on the cambrian faunas of Sweden.Forynation and locality.?Upper Cambrian. Ceratopyge zone.Limestone at Oland, Borgholm, Sweden. Limestone at Slemenstadwest of Christiania; black argilaceous shale, Christiania, Norway.PLECTORTHIS 2 Sp. ?Dr. J. F. Pompeckj" mentions two species of Orthis from theMiddle Cambrian green Paradox ides shales of Bohemia which appear,from the illustration, to belong to the genus Plectorthis. The mater-
''Jahrbiich k. k. geol. Reichsanstalt, XLV, p. 514, pi. xv, fig. 6 and fig. 7.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 273ial is too imperfect to base .specific determinations upon. DoctorPompcckj describes them as follows:(Plate XV, tig. ?.
)
Orlhh sp.?In the green Paradoxides slate of the Dlouha hora above the brook ofZbirov near Skrej there were found some impressions oi dorsal valves, which dei)artfrom Orth'i>i romingerl. The ribs are remarkably broad, Hat, and separated bynarrow intersjiaces; ribs may be observed to be split .several times.(Plate XV, fig. 7.)Orthissp.?The impression of a dorsal valve from green Paradoxides slate in thegorge above Luh near Skrej also departs from Orthis romingeri by its greater breadthand less distinct ribbing. ORTJSIA, new subgenus of OBTHIS.Ortliis lenticulark of authors is not an Orthis as restricted by Halland Clarke. ^ It appears to belong more nearly to the group of speciesassembled under Plectorthis. It departs from Plectorthis in its verythin shell, subequally convex valves, small umbonal cavity, and widevariation in form and surface characters, and is here placed under anew subgenus.The only species of the subgenus Orv-na is O. (O.) lenticidariHwhich occurs in the Upper Cambrian. Another species that is doubt-fully referred to the subgenus is O. ( (>. 'i) eurehensis a Middle Cambrianform that appears to be nearer (). {().) Jentioularis than to other knownspecies of the genus Orthis.The species referred to Orusia are:
Name.
274 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
Orthi^t lenticalarisf Kayseh, Pala'ontograpliica, Priuiordiale und untersil. Foes.Argentinischen Rei)ublik, J I, 1876, j). 9, pi. i, figs. 11, 12.Orthis lenticularis Brogger 1882, Die Sil. Etagen, 2 und 3, p. 48.Orthh lenficularifi Matthew, Trans. Roy. Soc. Canada, IX, 1891, p. 46, pi. xii,figs. 9a-d.Orthis lenticularIk var. slrophomenoidea Matthew, Trans. Roy. Soc. Canada, IX,1841, p. 49, pi. XII, figs. 12a, 12b.Dr. George F. Matthew in his excellent review of the descriptionsof this species gives a translation of Wahlenberg's original description,together with the Latin; also Dahnan's, Leopold von Buch's, andSalter's descriptions.He calls attention to the fact that if the reader will compare the sev-eral descriptions of this species by the authorities named he will besurprised at the diversity they exhibit. This diversity, DoctorMatthew thinks, is due partly to the imperfect descriptions of theearlier writers, but chiefly to the remarkal)le variability of the species."Doctor Matthew recognized the species in the Upper Cambrian, St.John, New Brunswick, and he also distinguished three varieties.Through Doctor Matthew's kindness I had the opportunity of studjdngthe types of the varieties.Through M. Schmalensee, collector of the geological survey ofSweden, I secured a large and hue series of this species from thinbands of limestone in the Olenus and alum shales at Olands and Nunne-burg. I also collected a quantity of the shells from the Upper Cam-brian of Manuels E-iver, Newfoundland. From this material anattempt has been made to select a series illustrating the great range ofvariation in form and surface markings; first, from Sweden; second,Newfoundland, and third, New Brunswick, I was not able to obtainsatisfactory material from Wales, but Mr. Davidson's figures illustratefully the peculiarities of the species as it occurs there. These illustra-tions will appear in the completed monogi-aph on the Cambrianbrachiopoda.Only one specimen was found in which the two valves were united.The convexity of the two valves is subequal, the ventral being a triflegreater.A very careful search has been made of casts of the interior to illus-trate the muscle scars and vascular markings. In a few instancestraces have been found. One of these shows the area (pseudospondy-lium) beneath the umbo of the ventral valve; also the main vascularsinuses. Doctor Matthew illustrates some traces of the vascularmarkings and muscle scars, l)ut they are almost too indefinite to be ofvalue.In a single specimen of the ventral valve from Olands, the cast ofthe umbonal cavity is nearly as sharp as in some specimens of Plee-torthis remnicha. The cavity is tripartite, the central division being
"Trans. Roy. Soc. Can., IX, 1891, pp. 46-47.
NO. 1395. CAMBRIAN BRACHIOPODA? WALCO TT. 275occupied by the diductor iniiscle scars, and the two hiteral divisions arccontinuous with the ridges representing the casts of the main vascularsinuses. I have been unable to determine positively whether there isa deltidium present or not. The delthyrium is clearly shown in sev-eral specimens. Casts of the interior of the dorsal valve from New-foimdland show the presence of crural plates that extend to the bottomof the valve; also short, but very definite, crura and small depressionsbeside the latter for the reception of the teeth of the ventral valve. Acast of the ventral valve shows that the ventral plates extend to thebottom of the valve, and specimens from Sweden show that the dentalplates and a transverse arching ridge sharply define, in certain indi-vidual ventral valves, the umbonal cavity.The average size of the specimens from Olands is about 5 by 6 mm.One dorsal valve is 7 by 1> mm. 1'hose from Nunneberg average from5 to () mm., with occasional shells 7 by 8. In Newfoundland greatnumbers occur 4 by 5 nmi., but there are also examples having aheight of 10 mm., with a width of 12 mm. Doctor Matthew states thatthe medium size of the shell is about 5 b}^ 6 mm. in the Acadian rocks.Doctor Brogger mentioned an example from Toien, Vestfossen, 10.5by 12.5 mm.I have noi attempted any detailed description of the species, asit is so variable in form and surface markings. An attempt wasmade to discriminate varieties in the material from Sweden andNewfoundland, but there was such a gradation in all of the charactersupon which such differentiation might rest that it was finally aban-doned. Doctor Matthew considers that he has reason for establishingvarieties among the New Brunswick forms. Whether these would beof value if a large amount of material w^ere available for comparisonis doubtful.Dr. E. Kaj^ser^' illustrates a shell that is apparently identical withO. (O.) lenticularis, which occurs in the sandstone at Tilcuya, Argen-tine Republic, in association with Olenus, AgnosUm^ etc. He alsoillustrates on Plate I, fig. 13, a dorsal valve of a small Ort?tis that inmany respects looks more like (). lenticularis than figs, 11 and 12. Ivery much doubt if they represent this species; in fact Doctor Kayserquestions his identification by an interrogation mark. He says of theshell:Another much smaller Orthis species occurs in the fine-grained sandstones of Til-cuya, associated with Olenus, Agnostus, Arionellus, Theca, and Orthis saltensis,which has just been described. The smaller Orthis species is transversely oval inoutline, with straight hinge edge, corre.sponding to the greatest breadth of the shell.The ventral valve is moderately arched, the dorsal somewhat less. The surface ofboth valves is covered with comparatively strong ribs, arranged in bundles. On themiddle of the ventral valve there is an especially well-marked rib or bundle of ribs.
? Paleontographica, Primordiale und untersil. Foss. Argentenischen Kep'b., p. 9,pi. I, figs. 11, 12.
276 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.To it eorre.spoiiclH on Mie doi>;al valve a well-marked .sinus, limited on each side by astrong bundle of ribs.The form just described agrees in the main so well with the tigures given by Salterand Davidson of the small English form identified with Wahlenberg's lenticularis,that I can hardly doubt its specific identity with the latter.Of Orthls sp, he remarks:Before me lies a cast from Tilcuya, representing a third Orthis species. It is almostequal in size to 0. saUensis, but differs from it by its outline, which is greatly pro-longed transversely, the greatest breadth at the hinge edge, and the feebly wing-likeprojection of the hinge corners. This last-named characteristic and the much largerdimensions distinguish this fossil also from 0. lenticularis. The surface of the shellhas been covered with very strong bundles of ribs.Formation and localities.?Upper Cambrian. Olenus schists, Nuniie-burg; Olands; alum shales, Andrarum; many localities in West Got-land, Sweden.In Norway Doctor Brogger describes it from Vestfossen in associa-tion with Peltura scarahseoides.In Wales it occurs at the following localities, according to Davidson.'*Orthis lenticularis seems to be confined to the LTpper Lingulaflags (Dolgelly groupsof Belt, or upper portion of the Ffestiniog group of Sedgwick), and occurs at Pen-morfa Church, near Tremadoc; near Criccieth, at Ogof-ddn Cliff, Swerny-y-Barcud,Rhiwfelyn, and in several other Welsh localities. 'In New Brunswick Dr. G. F. Matthew states that it occurs in greatnumbers and all sizes in limestone lentiles, inclosed in the black shaleof division 3a, at Germaine street, St. John.In Newfoundland I found the separated valves covering the surfacesof shaly limestone, also in the body of the thin limestone layers, about300 feet higher in the section than the zone of Paradoxides hicksi,Manuels River, Conception Bay.The following varieties of OrtJiis lenticidariH have been named byDoctor Matthew. I find essentially the same forms present in the col-lections from Sweden and Newfoundland. The variet}' strophomenoidesdoes not appear to be of varietal vahie. Many such occur in the Swe-dish material.ORTHIS (ORUSIA) LENTICULARIS ATRYPOIDES Matthew.Orthis lenticularis var. atri/poides Matthew, Trans. Roy. Soc. Canada, IX, 1891,p. 48, pi. XII, figs. 11a, 111).Original description. ?This form is comparatively smooth, though the ventral valveis sometimes concentrically wrinkled. This valve is distinguished by a median ridgeand somewhat flattened sides, and the dorsal valve has an unusually deep sinus.Size of the known examples, 6 by 6 mm. and 5 by 6 mm. for the two valves.Formation and locality
.
?Same as O. lenticularis in New Brunswick.
?Brit. Foss. Brach., Ill, p. 232.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 277ORTHIS (ORUSIA) LENTICULARIS LYNCIOIDES Matthew.Orthk lenticidaris lyncioides Matthew, Trans. Koy. Soc. Caiuula, IX, 1891, p. 49,pi. XII, iigs. lOa-c.Original description.?Distinguished by its sharp, strong, radiating ribs, large umbo,and high cardinal area. In some of the larger examples the radaiting ribs becomesubordinate to and are replaced on the newer part of the shell by concentric strife,reversing the usual position of the ribbed and the smooth parts of the shells of thisspecies. Size of tlie valves, about 6 by 8 mm.Formation and locality.?Same as O. lenticularis in New Brunswick.ORTHIS (ORUSIA ?) EUREKENSIS Walcott.Orthis eureJcensis Walcott, Mong. U. S. Geol. Survey, VIII, 1884, p. 22, pi. ix,fig. 8.Protorthis? eurekensis Hall and Clarke, Pal. N. Y., VIII, 1892, Pt. 1, p. 232.Orthis f eurekensis Schuchert, Bull. U. S. Geol. Sur. No. 87, 1897, p. 286.General form rounded .subquadrate; strongly convex. Surfacemarked by line, rounded, radiating ribs, live in the distance of a mil-limeter. Length of ventral valve, -t mm., width, 4.5; dorsal valve atrifle shorter.Ventral valve with a high median fold over the umbo, that widensand flattens toward the front margin, which is arched to I'eceive theprojecting median depression of the dorsal valve. The umbo curvesover to the apex, which overhangs the hinge line. Area low, andstrongly inclined backward. The interior cast shows that there was athick pseudospondylium, but no details of it are preserved. Dorsalvalve with a deep, gently curved, median sinus or depression, thatextends from the umbo to the front margin. In the cast strong ante-rior adductor muscle scars are shown on the sides of the mediandepression, and just back of them in the sinus what may be the smallerposterior adductor scars.OhservatioTis.?This strongly-marked shell suggests some of the moreconvex shells of O. {O.) lenticularis; it differs in its fine ribs; deepmedian sinus of dorsal valve and sharp fold of ventral valve; also inthe presence of a thickened shelf beneath the umbo of the ventralvalve that suggests a spondylium; this character, however, is some-times indicated in O. {().) lenticularis.Form.atu/n and locality.?^Middle Cambrian. Prospect Mountainlimestone just beneath Secret Canyon shale. East slope of ProspectMountain, Eureka District, Nevada.FINKELNBTIRGIA, new subgenus of, ORTHIS.This subgenus is based upon two species that difl'er from Plectorthisin having thick shells and strongly marked vascular trunks in theventral valve. The type of the subgenus, F. finkelnhurgi, with itsacuminate and sometimes alate cardinal extremities and subequallyconvex valves, is a very strongly marked type; the second species,
278 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.O. {F.) oaceola^ has o})tuso cardiiiiil extremities, and most of the exam-ples closely resemble in form Phctoi'thiH rermiicha. It is only whenthe specimens from the fine-grained sandstone of Trempealeau arestudied that one finds the thick shell and sti'ong- interior markings thatare unknown in species of Plectoi'thh.This subgenus is named after Mr. VV. A. Finkelnburg, of Winona,Minnesota, who has been one of the most intelligent and enthusiasticcollectors of Cambrian and Ordovician fossils in Minnesota in recentyears.The species referred to Frnl-elnhurgla are
?
Name.
1. O. ( Fhikdnbiirfila) flnkrinbui-f/i. new species2. O. ( Finkdntnirijia) 'ottrenltt, new speciesO. (Fitik-rlnhur</ia) o-frio/afurniriatd. new variety
Cambrian.
ORTHIS (FINKELNBURGIA) FINKELNBURGI, new species.Shell transverse with the cardinal angle extremities acuminate andin some examples almost alate. In the ventral valve the hinge lineslopes toward the beak at a low angle; in the dorsal valve it is nearlystraight. There is considerable variation in the height and width ofthe shell, this feature depending upon the extension of the cardinalangles. The convexity of the valves is subequal. In some examplesthe ventral valve is much more elevated and convex than in others,and the same is true of the dorsal valve. A low, clearly defined,mesial sinus occurs on the dorsal valve, being strongest in .young shells,and there is frequentl}^ a flattening of the mesial area on the ventral valve.The surface is marked by fine, rounded, radiating costse, crossed byconcentric lines, and, occasionally ridges of growth. In a ventralvalve 7 mm. in height, 11 nun. in width, there are two costa? in a dis-tance of 1 mm.The largest specimen of a ventral valve in the collection has a heightof 10 mm. with a width of 18 mm. The average shell is less than 8mm. in height.The cardinal area of the ventral valve is relatively high. It extendsbackward over the hinge line at an angle varying from 15'^ to 45? fromthe plane of the valve. The delthyrium is of moderate wddth andapparently partially covered by a deltidium. The cardinal area of thedorsal valve averages about one-half the height of that of the ventralvalve, although in some shells it is fully two-thirds as high. It extendsbackward at an angle of about 70? to the plane of the valve. It isdivided midway by a strong delthyrium. None of the specimens inthe collections show whether there was a chilidium present or not.In the interior of the ventral valve the strong teeth are supported
N0.1395. CAMBRIAN BRACHIOPODA?WALCOTT. 279by dental plates that extend to the bottom of the valve and bound theumbonal cavity (pseudospondyliinn). The only traces of the vascularsystem are the bases of strong vascular trunks. The adductor musclescars appear to have been carried into a very narrow space on an ele-vated ridge between the deep impressions made by the main vasculartrunks; in another specimen the points of attachment of the musclesare well advanced into the valve.In the interior of the dorsal valve a cast of the pseudocruraliumappears to have a small, cardinal process, or callosity, but it is toodoubtful to serve as basis for a statement that the cardinal process ispresent; there are traces of a median septum shown on the centralridge toward the center of the valve. The cardinal process occursin the anterior half of the umbonal cavity. The casts of the interiorshow that the crura are short and well defined, with relatively strong-dental sockets beside them. The only traces of the muscle scarsobserved are those of the adductor.OhservationH.?The exterior surface and size of this shell recalls O.{Fiiikslnhurgia) osceola. It difi'ers, however, in the accuminate ventralangles and strongly convex dorsal valve. In form the elongate cardi-nal angles relate this species to BlUingseUa {Otn.sla) sandheryi., but insurface and interior markings it materially differs from the latter.Formation and locality.?Upper Cambrian. St. Croix sandstone atTrempealeau, Devils Lake, Osceola Mills, Wisconsin. Minneiska,Minnesota.ORTHIS (FINKELNBURGIA) OSCEOLA, new species.The general form of this species is similar to that of P. remnicha.,except that it is usually more transverse. It is a smaller shell, aver-aging for the ventral valve a height of 8 mm. and width of 11 mm.,while P, remnicha averages 12 mm. in height and 14 to 16 mm. in widthin the adult shell. The radiating cost* are more uniformly roundedand regular and more numerous, except when compared with thevariety texana. The shell of O. (P.) osceola is thick like other formsof the genus with a result that the vascular markings are definitelyoutlined. In one specimen the anterior and posterior diductor scarsare beautifuUj'^ shown; also the large main vascular sinuses so charac-teristic of man}^ species of Billmgsella. The adductor scars, cardinalprocess and median septum are well brought out in a cast. Some ofthe dorsal valves approach quite closely to those of P. retntuchasidcata.J^ormation and locality.?Upper Cambrian. St. Croix sandstone,Trempealeau; Menomonie, one-half mile southeast of court-house;Mazomanie; Osceola Mills; Lodi, about one-third of a mile west ofrailroad station, Wisconsin. Just below fJiceUocephalus minnesotensisbed, Winona, Minnesota.
280 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.ORTHIS (FINKELNBURGIA) OSCEOLA CORRUGATA, new variety.At two localities of <A (I'Z) osceola a few specimens occur whichhave strong concentric ridg-es formed by the piling up of lines ofgrowth. The shell has a corrugated appearance that is very distinc-tive and it is designated as a variety.Formation and locality.?Upper Cambrian. St. Croix sandstone,Osceola Mills, Wisconsin. Just below DiceUocej^halus minnesotensisbeds, Winona, Minnesota.PROTORTHIS Hall and Clarke.Protorthis Hall and Clarke, Pal. N. Y., VIII, 1892, Pt. 1, p. 231, pi. vii a,figs. 14-21; Eleventh Ann. Rep. State Geologist New York, p. 273, pi. viii,figs. 3-7.Billmgsella Schuchert, Bull. U. S. Geol. Sur. No. 87, 1897, p. 334.Original diagnosis.?Shells small, transversely subquadrate or semicircular. Hinge-line straight, its length being equal to the greatest width of the valves. Valvesunequally biconvex, or subplanoconvex, the pedicle-valve being the larger. Thecardinal area is narrow on both valves, but is higher on the [ventral] pedicle-valve,and is transected by a broad delthyrium, which is closed below by a concave plateapparently produced by the union of the dental lamelUe, which are not continued tothe bottom of the valve; teeth distinctly developed. In the [dorsal] brachial valvethe cardinal area also bears an open delthyrium; the dental sockets are obscure andthe crural plates small; the latter appear to unite and forma low elevation acrossthe base of the delthyrium. Cardinal process absent or rudimentary in all the speci-mens examined. Muscular markings in both valves extremely obscure.Surface marked by distinct plications, with interstitial finer radii, which are crossedby delicate concentric strife; these are usually accompanied by a low sinus and foldon the brachial and pedicle-valves, respectively; interior very finely papillose.Shell-substance fibrous and apparently punctate.Type.? Ofthis Billingsi Hartt. St. John group.The characters of the St. John species are eminently comprehensive; first, theform of the shell is one more frequently met with among the strophomenidsthan among the orthids; the concave plate formed by the union of the dentallamellae is never found in Orthis proper, though occurring in Scenidium. In Orthisinaor (Mtamhonites this plate is always present, but always supported by a medianseptum and invarial)ly accompanied by the convex deltidium, which, so far asknown, does not exist in Protortlils; while in the group typified by (frthis Pepina,Hall (here designated by the term BiUingseUa), the convex deltidium of Clitam-honites is present and the concave or dental ]>late absent. The apparent absence ofa cardinal process in Protorthis may be due to tbe imperfections of tlie fragile shellsstudied. The specimens of the St. John shells are preserved as external and inter-nal casts, and from some of these there is reason to infer that the substance of theshell was punctate.Ohservatio7i.s.?A study of the various species here described underthe genus Protorthis. has not given data that will add to the abovegeneric description. All of the species have evidence of punctfe ofgreater or less depth on the inner and outer surfaces of the shell, butin none of them have punctse been found that penetrated through theshell; this ma}" be owing to the fact that all of the species are pre-
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 281served as casts in the sandstone or shale, and none of them have theoriginal shell substance, or a calcareous or siliceous replacement of it.A careful examination of a large number of specimens of the dorsalvalve fails to reveal a true cardinal process.The genus ranges from the Middle Cambrian well up into the UpperCambrian. The Middle Cambrian species are: Protorthis hlllmgsl^Protorthis latourensis, Protorthis 7iautes, Protorthis quacoensis^ Pro-torthis spencei. Upper Cambrian: Protorthis? mmnehergeiisis^ Pro-torthis wingi^ Protorthis^ species undetermined.The subgenus Lojperia has one species P. (Z. ) dougaldensis from theMiddle Cambrian. PROTORTHIS BILLINGSI Hartt.
Ortliis MUingsi Hartt, Acadian Geology, Dawson, 1868, 2(1 ed., p. 644, fig. 223.Orthis Ullingd Walcott, Bull. U. S. Geol. Survey No. 10, 1884, p. 17, pi. i, fig.1, la-d.Orthis hilUngai Matthew, Trans. Roy. Soc. Canada, III, 1886, p. 43.(Jrthis ? billingsi Matthew, Trans. Roy. Soc. Canada, VIII, 1891, p. 131.Protorthis billingsi Hall and Clakke, Pal. N. Y., VIII, Pt. 1, pp. 219, 232, pi.VII a, figs. 14-20; Eleventh Ann. Rep. State Geologist, New York, 1892,p. 273, pi. VIII, figs. 3-7.Billingsella billingsi Schuchert, Bull. U. S. Geol. Sur., No, 87, 1897, p. 158.The generic description follows very closely that of the type speciesP. hiUingsl in its main features. All of the specimens are compressedin the embedding shale, which renders it difficult to get a true concep-tion of the convexity and forms of the valves. The outlines may betransversely quadrilateral or subsemicircular or subquadrate. Usuallythe area is inclined backward over the hinge line, but it may be distortedby pressure so as to appear to incline forward. Young shells have awell-defined median sinus on the ventral valve that shows as a flattenedspace on the larger shells. A slight sinus sometimes appears on thedorsal valve. The surface of the shell varies in the number and sizeof the radiating ribs; sometimes they are scarcely visible toward thecardinal margin, and in other shells they are clearly defined all overthe surface; the increase in number is by bifurcation and interpola-tion ; fine, thread-like concentric stride and strong squamose lines ofgrowth cross the ribs.Ventral valve moderately convex, with the umbo and apex slightlycurved over the area or erect above the area. Area appears to beslightly concave, divided midway by a triangular delthyrium, whichis more or less closed by a concave plate that Hall and Clarke considerto be formed by the uniting of an extension of the dental plates orlamellte; from the casts it appears that the teeth were well developedand supported by dental plates that united at the center opposite thedelthyrium, but did not reach the bottom of the valve or a medianseptum; the free spondylium varied in length from a narrow rim
282 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.opposite the head of the delthyrium to a plate two-thirds or more ofthe length of the delthyrium.Dorsal valve uniformly and moderately convex, with the apexcurved over to the edge of the low area; area divided by a broaddelthyrium; casts of the interior show that the crura were strong,dental sockets shallow, and that the crural plates extended acrossthe umbonal cavity, uniting to define what may be called a pseudo-curalium. No trace of a cardinal process has been seen in a largenumber of casts of the interior, and Messrs Hall and Clarke did notfind any in a large amount of material.The casts of the interior show that the sliell was minutely punctate,and a shell preserving some of the inner layers has every appearanceof punctate structure,Ohservations.?This species ditfprs from all recognized species ofthe genus by its surface ribs and stria?.For)nation and locality.?Middle Cambrian. Paradoxides zone.Dark argillaceous shales of division Ic, Seeley street, St. John, Port-land Brook and Ratclifl's Millstream, New Brunswick.PROTORTHIS HELENA, new species.This species is founded on the cast of a ventral valve associated withProtosijyhon kenvpanimi. The form of the spondylium and area islike that of Protorthis latourensif<.^ but the smooth shell with a broad,rounded mesial sinus is unlike that species and also other speciesof the genus. The shell appears to have been thicker than that ofP. latoiirensl.^. Only traces of growth lines are preserved on the cast.The ventral valve is 10 mm. long with a width of 14 mm. The castshows that the teeth and dental plates were unusually strong.This species difi'ers from all others of the genus by its smooth ornearly smooth surface and strong median sinus. It suggests Syntro-phia hiTobuensm at first sight, but there is no evidence of a medianseptum supporting the spond^dium.The specific name is that of Mrs. Walcott who collected the specimen.Formation and locality.?Middle Cambrian, St. John formation,Kennebecasis River, St. John County, New Brunswick.PROTORTHIS LATOURENSIS Matthew.Kuionfma kitoureiisis Matthew, Trans. Roy. Snc. Canada, III, 1886, p. 42, pi. v.figs. 18, 18a-c.Kuiorglna latoarensis Hall and Clarke, Pal. N. Y., VIII, 1892, Pt. 1, pp. 93, 95,238, pi. IV, figs. 18, 19, 20.Original description.?^Valves narrowly semicircular, broader than long, flat; umboneslow; greatest thickness in the posterior third; hinge line shorter than the width ofthe shell.Dorsal valve with a distinct median der)ression extending from the umbo to thefront margin, and with low ridges diverging from the Ijeak toward the lateral thirdof the front of the valve. (Jmbo not elevated above the hinge area, which is exceed-
NO. 1395. CAMBRIAN BRACHIOPODA? WALCOTT. 283ingly narrow or absent. Hinge line with two sharp, slightly projecting teeth nearthe umbo [crura?].Ventral valve with a narrow median ridge extending two thirds of the length ofthe valve toward the front margin; also with a fainter ridge on each side divergingtoward the lateral third of the border of the valve; umbo very low; hinge area per-ceptible but very narrow, longitudinally striated, and having a minute tooth on eachside of the very narrow and small foraminal opening.Surface ornamented with about forty or fifty line, faint, radiating strite; those ofthe middle fifth are close, continuous, and straight; a few on each side of these aremore divergent, wliile those near the beak of the shell are fainter, closer than thelast, and moderately arched outward toward the lateral borders. The surface of thevalves is also marked by very fine but distinct concentric striae; and at somewhatregular intervals by about twelve more distinct lines of growth. The concentricstritB are usually as distinct as the radiating. Casts of the interior of the valvesexhibit a smooth surface with some irregular, sinous, radiating stri;e.Length 7 mm., width 11 mm. Length of hinge line, 8 mm.Observations.?Doctor Matthew kindly sent me the types and cotypesof this species, and from them and collections in the United StatesNational Museum, sufficient data was obtained to clearly show that hisopinion that tlie species belong to Protorthls and not Kukm/inayf^^correct. As far as known the characters of the area, teeth and freespondylium are the same as in P. InlllmjsL The smooth casts suggestKutorgma^' but the ribbed shells recall P. quacoensis and the area withopen delthyrium and free spondylium place the species in Protorthis.Its Aery tine surface riljs diflerentiate P. latourensis from all otherdescribed species.Format loth and locality.?'MXA&Xo, Cambrian. St. John shales, divi-sion Ic, Portland, New Brunswick.PROTORTHIS 'LIE.VIS, new species.Ventral valve transversely semicircular, moderately convex; surfaceof cast smooth; area overhanging the hinge line at about 30? from theplane of the margin of the valve. The cast shows a very clearly definedfree spondylimn. Shell about 6 mm. in width and 4 mm. in length.This is the only representative of the genus known outside of theAtlantic basin Cambrian fauna. All other species occur in NewBrunswick and Cape Breton. Its smooth surface and inclined areadistinguish it from other species of the genus.Formation and locality.?Middle Cambrian. St. Croix sandstone,one-half mile southeast of county court-house, Menominee, Wisconsin.PROTORTHIS NAUTES, new species.This species has the same type of punctate interior surface as P.hillingsi, and casts of the exterior are marked by minute, closely setpapillffi that are casts of the punctfe in the shell. Traces of the shellshow the same type of papilla. It is highly probable that the shell
a See figures 18-20, Pal. N. Y., VIII, Pt. 1, pi. iv.
284 PROCEEDINGS OF THE NATIONAL MUSEVM. vol. xxviii.was punctate. The exterior form is like that of P. hUlingsi, but inthe surface ribs it differs from the latter and other described speciesof the genus.A ventral valve has a length of 5 mm. ; width, 8 mm, A dorsal valve,length, 7 mm.; width, 10 mm. There is considerable variation in therelative proportions between length and width.Formation and locality.?Middle Cambrian. Dark argillaceousshales, Wasatch Range, near Montpelier, Idaho.A similar shell occurs in the shaly limestone of the Middle Cambrian,3 miles east of Antelope Springs, Utah.PROTORTHIS (?) NUNNEBERGENSIS, new species.Shell transversely semielliptical, plano-convex. Surface with veryline ribs tiiat increase by interpolation and bifurcation; on some shellsbands of slender ribs are delimited by stronger ribs, usually 2 to .5between 2 more prominent ribs; tine concentric strire give a crenulatedaspect to the radiating ribs. Casts of the interior and exterior appearto be minutely papillose, indicating puncttw in the shell.Ventral valve moderately convex, with the apex curved down to themargin of the area; area and interior unknown. Dorsal valve flat orvery slightly concave between the umbo and margins; apex slightlyelevated above the plane of the surface and cardinal line; a mediansinus is present in some shells.Ohservations.?It is a little hazardous to refer this species to Protor-this, as only the general form and surface are known. The nearlyplano-convex valves and surface relate it moi'e nearly to Protorthisthan Plectorthis^ and it does not appear to fall within Leptsena,Rajinesquina,, or Strojyhomena. The specimens were collected by Mr.Von Schmalensee in a dark, argillaceous shale above the Ceratopygelimestone and below the lower graptalite shale.Format)on and locality.?Upper Cambrian. Mossebo, Nunneberg,Vestergotland, Sweden.PROTORTHIS QUACOENSIS Matthew.Orlfm (juacoensis Matthew, Trana. Roy. Soc. Canada, III, 1886, p. 43, pi. v,figs. 20, 20a-c.Orthis'! quacoemh Matthew, Trans. Roy. Soc. Canada, VIII, 1891, p. 131.Protorthis quacoensk Hall and Clarke, Pal. N. Y., VIII, Pt. 1, p. 232, pi. viiA, fig. 21.BillmgseUa (juacoensis ^cnvGHEKT, Bull. U. S. Geol. Sur., No. 87, 1897, p. 159.Original description.?A small species. Subquadrate to semielliptical in outline,broader than long, widest near or at the hinge line, which is not produced; moder-ately convex, highest in the posterior third, flattened toward the front and sides.Umbones not prominent.The dorsal valve rises rapidly from the hinge line, and has but a narrow, flattenedspace at the angles. It is about one-third as high as it is long. The hipge plate hasa narrow area, which is striated lengthwise, and bears two tooth-like processes closeto the umbo, the point of which is bent down to the hinge line.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCO TT. 285The ventral valve is somewhat more elevated than the dorsal. Hinge area trian-gular, sloping backward to the umbo, and bearing fine striae parallel to the hingeline. Umbo elevated above the hinge line to a height fully equal to one-third of thelength of the valve. Foramen [delthyrium] large, truncate-pyramidal in outline.Surface of the valves ornamented by about twenty rounded plicse, radiating [inthe ventral valve] from the edge of the hinge area, opposite the foramen [delthyrium]and not from the beak alone; those on the middle fifth of each valve are crowdedtogether, those outside of these are more prominent, and are continuous from theumbo; those toward the hinge line are faintly marked and widely separated. Theradiating plicae do not [or rarely] increase by bifurcation. Both valves bear numer-ous concentric striae, and are also marked by a few distinct squamose lines of growth.The mold or cast of the interior of the valves of this species is nearly smoothor is marked by faint radiating stria^; the margin of the mold, however, oftenexhibits a crenulated appearance corresponding to the plicae of the outer surface.There is a wide, smooth median depression at the top of the mold of the dorsal valvenear the umbo.Length of the valve in 0. qaacoeiisis, 5 mm. ; width, 8 mm.Observations.?Doctor Matthew very kindly sent me his types of thisspecies. A comparison of them with P. hilUngsi shows that the twospecies are quite distinct, and P. quacoensis is unlike any other shellreferred to the genus.As far as seen the free spondyliumof the ventral valve is short; theteeth are clearly shown in the cast. The pseudo-cruralium of the dor-sal valve is much more clearly defined than in P. Mllingsi, the area ishigher, and traces of the adductor muscle scars are preserved.Formation and locality.?Middle Cambrian. Paradoxides zone,division Ic, Portland and at Porter's Brook, St. Martins, New Bruns-wick. PROTORTHIS SPENCEI, new species.This is a strongly marked species despite the fact that only a fewspecimens have been found, and these are flattened in the shale. It isdistinguished by its rounded, subquadrate outlines and narrow, sharpribs with strong interspaces?six ribs in a distance of 5 mm. at the frontmargin. The area of the ventral valve has a broad delthyrium witha concave plate or free spondylium, covering the greater part of it.The interior surface of the shell is finely punctate. A flattened ven-tral valve has a length of 17 mm. ; width, 18 mm.This shell is associated with P. nautes. It diflers from it in itslarger size, sharper ribs, and broader interspaces between the ribs.The species is named for Mr. R. S. Spence, of Montpelier, Idaho, agentleman who made large collections from the Middle Cambrian shalesof Idaho.Formation and locality.?Ma&^q, Cambrian. Argillaceous shales,Wasatch Range, near Montpelier, Idaho. Shaly limestones, 3 mileseast of Antelope Springs, House Range, Utah.Proc. N. M. vol. xxviii?04 19
286 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.PROTORTHIS WINGI, new species.General form traiisvers(>ly suhelliptical. Surface marked l)v about20 sharply ridged ril)s with interspaces equal and usually greater thanthe width of the rib; shell with numerous small and many larger andscattered punctie on the inner and outer surfaces. The largest ventralvalve has a length of 6 mm. ; width, nnu.Ventral valve convex, elevated at the umbo and beak; area highand divided midway by a strong delthyrium which is partially closedby a concave free spondylium as in JR. hiJlhir/.'^i, teeth strong, dentalplates extended toward the center to unite and form the free spon-dylium.Dorsal valve slightly convex, with a broad median sinus that isusually bounded by one or two large ribs; casts of the interior show anarrow area, broad delthyrium, and the cast of a siuall, l)roadly trian-gular, elevated area opposite the umbo that probal?l\" served as thecardinal process for the attachment of the diductor muscles.Ohisercatio)is.?This species is most nearly related to Protorthls
'lumtes; it differs, as far as known, in the character of the interior ofthe dorsal valve, the large puncta^ scattered among the tine punctii?,and the sharp ridged ribs. One cast of an interior of a ventral valveappears to indicate that that shell Avas without the free spond^dium.It not infrequently occurs in Protoi thU IvUhuj.si that the free spondyl-ium is reduced to a narrow rim aV)out the margin of the delthyrium,and it may ))e that in this shell it was al)sent.The specific name is given in memory of Rev. Augustus Wing, whodid so much excellent work in the vicinity of Swanton, Vermont,which was utilized by Mr. Billings and Sir William E. Logan.Forviation and Jocdh'fif.?Upper Cam)>rian. Dark argillaceousshales, about one-half mile south of llighgate Falls, Vermont.PROTORTHIS, species undetermined.Ventral valve convex, elevated at the undio, apex incurved. Thecast of the umbonal cavitv (pseudospondylium) indicates well devel-oped teeth and dental plates. On the cast 6 radiating ribs occur inthe distance of i nun.: area aV)out vertical. The surface of the castindicates that the interior layer of the shell was lineh' pimctate.Length of valve 4.5 nun., width 5.5 mm.Only one specimen of a cast of a ventral valve of this shell wasfound. It suggests by its convexity and surface some of the moreconvex forms of Protarthis qnacoensis.Formation and locality. ? Vr\^^^^x Cambrian. Tonto terrane. Thinbedded siliceous limestone at mouth of Kanab Canyon, Grand Canyon,Arizona.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 287LOPERIA, new subgenus of PROTORTHIS.This subg'enus is characterized by the form of the valves. The ven-tral valve is elevated at the umbo and flat or slightly concave from theumbo to the margins; the dorsal valve is strongly and regularly convex.The description of the type species, ProtortJds {Loperia) dougaldensia^is that of the subgenus and species, as it is the only species thus farknown of the subgenus.PROTORTHIS (LOPERIA) DOUGALDENSIS, new species.General form rounded subquadrate. Hinge line straight andshorter than the greatest width of the shell; cardinal extremitiesobtusel}" angular. Relati\e convexity of the valves reversed, as inDinoi'thiH pectinella of the Ordovician fauna. Surface of the dorsalvalves with strong, simple, rounded ribs that increase by interpola-tion; fine concentric stria^ and lines of growth that sometimes formridges, cross the ribs, curving in the interspaces and over the ribs;these ribs are more prominent and numerous (30 to 40) on the dorsalthan on the ventral valve; on the latter the ribs are broad, with nar-row interspaces, and about 20 to 25 in number; casts of the exteriorand interior surfaces have numerous fine, thickly set, elevated papilla?that appear as the casts of the punctte in the layers of the shell; onsome specimens the papillw are cylindrical and elevated, which indi-cates that they penetrated deep into the shell substance. All indica-tions point to a punctate, shell; in all the material representing thespecies the shell has been removed ])y solution, only the casts of theinner and outer surfaces remaining.The largest xentral valve in the collection has a length of IS nun.,width 25 mm.; dorsal valve, length 22 nun., width 27 mm.Ventral valve elevated at the umbo and gently concave from theumbo to the front margin and flat to the cardinal extremities. Arearelatively low and overhanging the hinge line at an angle of about 45";it is divided midway by a broad delthyrium that is more or less closedby a deeply concave plate, across which the transverse stria? of growthof the area pass. The concave plate appears to be identical in formand position with the free spondylium of t^he genus Protorthls. A castof the interior shows very strong teeth and supporting dental plates;the edges of the dental plates appear to lie continuous with the concaveplate or free spondylium.Dorsal valve strongly and regularly convex, with a slight flatteningof the median line and sometimes a shallow sinus. Casts of theinterior show a strong area with a triangular delth3a'ium; the umbonalcavit)' is strongly /)utlined by the crural plates so as to form a pseu-docruralium; crura well developed, with clearly defined teeth socketsback of them. No traces of a cardinal process have been seen in ten
288 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
?pecimens .showing- tine casts of the area, delth3'riuni, and unibonalcavity.Ohi^ervatloiis.?This tine species is unique amonj*; Cambrian brachi-opods in having a depressed, flat, or convex ventral valve and stronglyconvex dorsal valve. In its^ punctate shell, free spondyliuni, andabsence of cardinal process, it is allied closely to Protorthis; thedepressed ventral valve and convex dorsal valve serve to distinguishit as a subgenus of Protorthi^^ which 1 have called Lcyperia in recog-nition of the effective work of Mr. S. Ward Loper, who collectedthe material representing this and many other Cambrian fossils inCape Breton and New Brunswick.Foriiiation and locality.?Middle Cambrian. Division 2?probably2b?of Matthew's section. Dougald Brook, tributary to Indian River;one-fourth mile from lower bridge, P^scasonia, Cape Breton, NovaScotia. SYNTROPHIA Hall and Clarke.Syntrophia Hall and Clarke, Pal. N. Y., VIII, 1892, Pt. 1, p. 270; 1893, Pt. 2,p. 216; Thirteenth Ann. Rep. State Geol. N. Y., 1895, p. 836.Original description.?Shell transversely elongate, biconvex, with straight hinge-line, whose length nearly equals the greatest diameter of the valves; each valvemedially divided by an open delthyrium. External surface smooth, with fine con-centric lines visible only about the margins; the inner shell-layers show a stronglyfibrous radiating structure without punctation. The pedicle valve bears a more orless clearly developed median sinus and the brachial valve a Inroad, indistinct fold.On the interior the teeth are very small, lying at the extremities of the delthyrialmargins and supported by dental plates, which converge and unite before reachingthe bottom of the valve. Thus is formed a deep but short spondyliuni, which is sup-ported, near its apical jwrtion, by a median septum, but is free for fully one-half itslength.In the brachial valve there are also two convergent plates bounding the deltidialcavity, larger and stronger than those of the opposite valve. These plates may restupon the bottom of the valve and, toward the posterior extremity, probably alwaysdo; but anteriorly they become free, forming a spondyliuni, which is sujiported liy amedian sejitum extending beyond the anterior edge of the plate. Thus these twovalves, which are very similar in exterior, the pedicle-valve being only slightly themore convex and with a low median sinus, are also closely alike on the interior, eachbeing furnished with a spondyliuni.Type.?Syntrophia lateralis, Whitfield (sp. ).Ohsewations.?Messrs. Hall and Clarke referred Orthh harabuensisand Triplesia primordialis among Cambrian species to Synthrophiaand of Ordovician species, Trij^le^la lateralis., StricMandtnla ? arethum,S. ? arachne and (Jauiardla, ealclfera.Orthis ? arvuKla Billings, of the Lower Ordovician, certainly has aclose resemblance in the spondyliuni of the ventral valve to this genus,and it may represent a radially striated form, as suggested b}" Messrs.Hall and Clarke." Of the relations of the shells referred to Syn-
"I'al. N. Y., VIII, Pt. 2, p. 218.
NO. 1395. CAMBRIAN BRACHTOPODA?WALCOTT. 289frojyhia^ to SfyricMandinla^ they consider that the points of structuremay represent the strnctui'e which is represented l)y the Sti'liMand!'iiias of the hiter Sihirian and Devonian. Mr. Billings noted the rela-tionship existing between his Gamarella calolfera and Stricklandinia/'-It is probable that S. nrachne^ S. arethnsa, and similar forms shouldbe referred to a distinct genus. They are not typical Stri('khitidiii!ai<^and they differ in surface and shape from Synirophla late>'alis.The Cambrian type of Syntrophia is 8. rotundatus of the UpperCambrian. It has a spondylium in each valve supported by a medianseptum, and a short area divided by a large open delthyrium.The Middle Cambrian species, S. texana^ and Upper Cambrianspecies, 8. ahnormis differ from the type species in having the greaterportion of the bottom of the spondylium of each valve attached to thebottom of the valve, no evidence of median septum having been foundexcept in a cast of a dorsal valve. 8. primordialh has no medianseptum in the dorsal valve, in this respect resembling the dorsal valveof CamareUa voJhorthl. There is considerable variation of form in thedifferent species, but this is not much greater than the varieties of thetype species, 8. lateralw.The species referred to the genus ma}^ be divided into two groups,the plicate and nonplicate. The plicate species begin with aS". te.vmia^and includes 8. abnormiH^ 8. orientalis, and 8. MlUngsi, all of theUpper Cambrian. The nonplicate or smooth species are 8. alata^ 8.rotiindata^ 8. Ijarabuensis, and 8. prim,ordialis, of the Uppei- Cam-brian, and 8. adcifeni., 8. lateralis, 8. mmdma and allied forms, ofthe Ordovician. SYNTROPHIA ABNORMIS, new species.CamereUa calcifera Meek, .Sixth Ann. Rept. U. S. Geol. Sur. Terr., 1873, p. 464.The general form varies from transverse to elongate. Valves bicon-vex, with dorsal very convex in some specimens. Hinge line straight.Surface marked by concentric stria^ and imbricating lines of growthcrossed by fine, rounded, radiating stria? and a variable number ofrounded ribs; specimens occur with four ribs in the sinus of the ven-tral valve and four on each slope outside the sinus; in other ventralvalves only a trace of ribs can be seen. On the dorsal valve there areshells without a sign of ribs, and others with a trace of rib on themedian fold to three ribs on the fold and traces on the lateral slopes.The largest shell has a length of 7 mm. ; width 9 nun. ; there is greatvariation in the proportion of the length to the width.The ventral valve has a broad, strong sinus that depresses the frontof the valve; area well defined, with a large, open delthyrium. Castsof the interior of the ventral valve show a well-marked spondylium
?Pal. Foss., I, p. 84.
290 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.and very stroiiii main \ asciilar .sinuses; l)()tli spondyliuin and sinusesrocall those of liiUiiKjHcJla pliattdla. Sortions of the ventral valvecut across the umbo show the spondylium attached to the bottom ofthe valve. The tiabelliform diductor and adductor muscle scars areclearly- shown outside of the vascular sinuses.Dorsal valve with an elevated median fold that gives a strong con-vexity to the valve; area low, with a strong, open delthj^rium; theinterior of the valve shows a shallow spondylium attached to the bot-tom of the valve posteriorly, and prol)ably supported by a low medianseptum toward the front, and well defined anterior and posterioradductor muscle scars; narrow main vascular sinuses occur, and slendervascular lines radiate forward from the muscle scars.Ohservatloux.?This species differs from all allied forms by its vari-ation in outline, convexity, ribs and internal markings. Some shellsapproach closely to those of S. texaiKi^ but each species has a majorityof shells that are <|uite unlike those of the other. Another point ofresemldance is the form of the spondylium as shown by cross sections.A variety of S. te.rdna from CV)ld Creek Canyon, Texas, has someshells that approach those of S. <(hri<>i'mis in the extravagant develop-ment of the fold on the dorsal valve and sinus on the ventral valve,but in other respects the}- diff'ei- from it. The form of the spond^diumand plications or ribs, suggests the genus Pnr<ixtro'p}da Hall.Foi'in(di(ni and locality.?Upper Cambrian. Head of Deep CreekYellowstone National Park, Wyoming. North of East GallatinRiver, near Hillsdale, Dry Creek, Gallatin Valley, Montana.SYNTROPHIA ALATA, new species.This species is characterized l)y its transverse form and extendedcardinal angles. P^xterior surface marked by concentric striw andlines of growth and interior surface by tine, radiating strite. A trans-verse section of the ventral valve at the umbo shows the spondyliumwith a strong median septum supporting it. The interior of the ven-tral vahe was marked by two strong main vascular sinuses startingfrom the sides of the spondylium.Foraiatlon and locality.?Upper Cambrian. Honey Creek, BurnettCounty, Texas.SYNTROPHIA BARABUENSIS A. Winchell.OrUih hiralmeimx A. Winchell, Am. Jour. 8ci., 2(1 ser., XXXVII, 1864, p. 228.Leptu'int Ixtralnicuah WiiiTFiKLi), Ann. Rep. Geol. Survey Wisconsin, 1877, p. 60.Leptivna Ixvrahueims WiiiTKrRLi), (Jeology of Wisconsin, IV, 18S2, pp. 171, 195,pi. I, ti<is. 6, 7; pi. HI, lig. 6.Sy'niroj)hiaharabue)iiih?{\\ArAi\dCi,\RViv., Pal. New York, VIII, 1893, Pt. 2, p. 216.J>c.scnj)ll()ii {1)1/ Mr. Wltitfiehl).?Shell of medium size or smaller, measuring abouthalf an inch or less than half an inch along the hinge line; form semielliptical, long-e.st on tJie hinge and more than half as wide again as long; extremities of the hinge
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 291
often submucrunate; front of the valveK rounded or slightly eniarginate in the mid-dle. Ventral valve the most convex, and marked by a strong, angular mesial eleva-tion, nearly one- fourth as wide on the front of the valve as the width of the shell;area moderately high and nearly in the plane of the valve; cardinal borders verygradually sloping from the center to the extremities of the cardinal line. Dorsalvalve less convex than the opposite, and marked by a subangular mesial depression,corresponding to the fold of the opposite valve; area linear. Surface of the shellapparently smooth, or at least so far as can be determined from either the internalcasts or from the matrix.I had some doubt regarding the positive identity of this species with that describedby Professor Winchell in c-onsequence of the following remarks which occur in his?description: "Surface with 16 or 18 ribs visible on the casts, the strongest of whichlimit the mesial sinus," and again, " apparently of the type of Orthis hiforta." Inexamining a number of specimens I had not been able to detect any stria^ or ribs,and felt somewhat inclined to regard it as a distinct species from that one. I have,however, through the kindness of Professor Winchell, been able to make a directcomparison with one of his original specimens, and should consider them as identi-cal. The specimen sent me has the mesial fold (of the ventral valve) remarkablystrongly defined by a depressed line on each margin, the center aj^pearing tumid,which I think is in part due to accident. The specimen corresponds closely with theventral valve we have figured, exc^ept in the strongly defined mesial fold.Ohservations.?This is the same type of Syntrophia as 8. primordl-alis. It differs in its more rounded outlines, shallow, rounded sinusin ventral valve, and usually a less pronounced fold on the dorsalvalve. Evidence of a short median septiun at the end of a very shortspondylium in the dorsal valve is shown l)y one cast.Formation cmd locality.?St. Croix sandstone, north end of DevilsLake near Baraboo and Trempealeau, Wisconsin.SYNTROPHIA BILLINGSI, new species.General form transversely subquadrate; rounded; biconvex, withthe dorsal valve elevated on the median fold. Surface marked by afew imperfectlv developed ribs on some shells, while others have onlyconcentric stria? and lines of growth. Ventral valve with a relativelyshallow median sinus, in which obscure, narrow ribs sometimes occur;none of the specimens in the collection show the area, but from theprofile of the valve it must have been of moderate height, with therather sharp apex curving slightl}^ over it; a single poor cast of theinterior shows the outline of a spondylium much like that of S. pri-niordialls; the evidence of the presence of a median septum is a darkline in front of the end of the cast of the spondylium, which indicatesthat the shell sulxstanco extends down into the limestone and that it isthe median septum. Dorsal valve with a small umbo and apex thatextends forward into a prominent median fold that may be plicated orsmooth; one partially exfoliated shell shows three plications on tliefold and three or four on each lateral slope of the valve.Oh)<ervations.?This species belongs to the plicate group of thegenus represented b}' S. texana and S. ahioniii.s. It differs from S.
292 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.texana in being less convex and in having a shallower ventral sinus,less prominent dorsal fold, and more obscure plications.The specific name is given in memory of Elkana Billings.Forvmtion and locality.?Upper Cambrian. In lentile of limestoneinterbedded in silicious shales above the Olenellus shales, 1 mile eastof Parker's quarry, Georgia Township, St. Albans County, Vermont.SYNTROPHIA NUNDINA, new species.Triplesia cafc(/em Walcott, Mong. U. S. Geol. Sur., VIII, 1886, p. 75, pi. ii,figs. 7, 8.The nonplicate, convex species that is found in the Lower Ordo-vician of the western United States has usually been referred toCameTella or Triplesia caldfera. It is much like the latter, but dif-fers in being less convex, with apex of valves less pointed and incurved.Formation and locality.?Lower Ordovician. Pogonip formation.Spur on ridge extending out southwest from Wood Cave; lower east-ern slope of ridge, east of Hamburg Ridge, facing Secret Canyonroad; west side of Goodwin Canyon; base of Pogonip limestone north-east of Adams Hill, Eureka District, Nevada.Pinkish colored limestone 80 to 75 feet above Algonkian rocks,Williams Canyon, above Manitou, Colorado.SYNTROPHIA ORIENTALIS, new species.This species is closely related in form and surface characters toSyntrophia texana and some forms of 8. ahnormis. It differs fromthem in details of surface ribs. On the dorsal valve there are two orthree faintly defined radiating ribs on each side of the median fold,which has obscure ribs upon it. Corresponding ribs occur upon themesial depression of the ventral valve and the side slopes adjoining thedepression. The material representing it is too limited to warrant anidentification with an}^ described species. S. orientalis is the trans-Pacific representative of S. texana.Formation, and locality.?Upper Cambrian. Lower part of ChaoMi Tien (?) limestone, 2.7 miles southwest of Yen Chuang, Provinceof Shantung, China. Collected by Eliot Blackwelder and Bailey Wil-lis of the Carnegie Institution Expedition, 1903.Syntroj^hia, sp.?Three specimens of a ventral valve, very much likethat of S. primordialis Whitfield, occur at the same locality as /S.orientalis. SYNTROPHIA PRIMORDIALIS Whitfield.Triplesia priynordiaiis WniTFiEhB, Ann. Rep. Geol. Surv., Wisconsin, 1877, p. 51.Triplesia primordialis Whitfield, Geology of Wisconsin, IV, 1882, p. 172, pi. x, figs.1, 2.Triplesia primordialis Hall, Pal. New York, YIII, 1892, Pt. 1, p. 271.Syntrophia primordialis Hall and Clarke, Pal. New Y^ork, VIII, 1892, Pt. 2, p. 218.Original description..?Shell small, measuring less than half an inch in width; trans-versely oval in outline, and (juite ventricose in i>rofile; hinge line straight and about
NO. 1395. CAMBRIAN BRACHIOPODA? WALCOTT. 293half as long as the width of the shell below; area narrow. Ventral valve with astrongly deiiressed, rather narrow and rounded mesial sinus. Dorsal valve with anarrow, sharply elevated fold not extending quite to the l)eak; side of the valverounded. Surface smooth in the casts, but jiresenting the ai>pearan<;e of liaving beenexternally striate. Processes in the interior of the dorsal valve apparently forminga small spoon shaped pit at the beak.OhseriKiUons.?Casts of the interior show the form of the spondy-lium and supportino- median septum in the ventral valve; also thesmall, short spondyliimi in the ventral valve, which appears to beattached to the bottom of the valve without a median septum.This species differs from S. harahuensis in its smaller size, less trans-verse outline, and more pronounced mesial depression on the ventralvalve. Examples occur of the dorsal valves of the two species thatare very similar. Some of the shells approach certain forms of 8. cal-cifera^ but the larger number are less convex and more transverse andwith more obtuse cardinal angles. A shell closely allied to S. primor-dialis, and apparently identical, occurs in the Reagan limestone. Onlythe exterior is known.Formation and locality.?Upper Cambrian. St. Croix sandstone,Taylors Falls, Adams County, Wisconsin. Abundantly at Minneiska,and more rarely at River Junction, Houston County, and near Winona,Minnesota.Numerous examples of a closely related shell occur in the upper partof the Reagan limestone in the SE. corner, NE. i sec. 2,T. 4 N., R.13 W., 15 miles northwest of Fort Sill, Wichita Mountains, OklahomaTerritory.A single ventral valve of the nonplicate shell with a deep sinuscomes from the Upper Cambrian, Reagan limestone, Indian Territory,NW. i sec. 1, T. 2 S., R. 1 E. Specimens of the ventral valve of ashell apparently identical with S. i>r!inordlalis occur in the limestonepassage beds between the Upper Cambrian and Ordovician on the northside of Tepee Creek, east side of Big Horn Mountains, Wyoming.SYNTROPHIA PRIMORDIALIS ARGIA, new variety.This specimen is separated as a variety of S-iyriinordialis on accountof its less convexity and more shallow median sinus which has threerudimentary plications in it.Fonnatlon and loadity.?Upper Cambrian. St. Croix sandstone,Reeds Landing, foot of Lake Pepin, Minnesota.SYNTROPHIA ROTUNDATA, new species.General form rotund, unequally biconvex; hinge line short. Sur-face marked by fine, concentric striae and low, imbricating varices ofgrowth. The longest shell observed has a width of 18 mm. ; length11 mm. Ventral valve convex at the umbo and beak, but depressedtoward the front by a strong, broad, and deep median sinus. Area low,
294 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.
short, and divided midway by a relatively" larye triangular delthyrium.Transverse sections ot" the umbo near the beak show the cross sectionof a well developed spondylium supported on a medium septum. Dorsalvalve about as convex as the venti'al on the umbo but the strong,})road median fold makes it more strongly convex anteriorly. Crosssections at the umbo show a spondylium and supporting septum verymuch like that in the ventral valve.Ohservatloufi.?This species is taken as the Cambrian type of thegenus 8yntroj)hia, It has a spondylium in each valve supported bya median septum in the same manner as in the Ordovician type of thegenus *S'. lateralis. Its rotiuid form, deep ventral sinus, and strong-dorsal fold serve to distinguish S. rotundata from other species of thegenus.Formation and locality.?Upper Cambrian. Limestone on WolfCreek, Big Horn Mountains, 14 miles west-southwest of Sheridan,Wyoming. SYNTROPHIA TEXANA, new species.CamereUa sp.? IShumard, Am. Jour. Sci., 2d ser., XXXII, 1861, p. 221.This ma}^ be called the plicate species of the group of forms referredto Sy/d)'op/iia. It is intimatel}^ connected with the smooth forms b}'a series of shells that vary from 1(1 ribs on a valve to 1. In formS. texana is much like S. ahnormis; also in the cross section of itsspondylium. The}' dift'er in the extravagant development of the pli-cations of ,6'. ahnonnis, a feature characteristic of a large series ofspecimens.S. texana occurs in great numbers in one of the upper limestonebeds of Packsaddle Mountain.The average size of the larger shell is, width, S mm., length6 to 7 mm.It is probable that this is the shell referred to by Doctor Shumardas CamereUa sp. 'i He said of it
?
There are several .specimens of small brachiopod in the Texas State collecfion fromthe Potsdam sandstf)ne of Morgan's Creek, Burnet County, which appear to belongto the genus Camerdld recently created by Mr. E. Billings. Unfortunately, however,they consist merely of detached and imperfect valves, too much weathered for satis-factory determination and description.'^'Formation and JocaJlty.?Upper Cambrian. Packsaddle Mountain,Llano C/Ounty, Texas.SYNTROPHIA TEXANA LAEVIUSCULUS, new variety.A variety occurs in Texas with few traces of plication in the sinus;with one, two or three strong plications on the dorsal fold, or none atall; it approaches S. ahnm'mis in some of its extreme forms where the
"The Primoi'dial Zone of Texas, with descriptions of New Fossils, American Jour.Sci., 2d ser., XXXII, 1861, p. 221.
NO. 1395. CAMBRIAN BRACHIOPODA-WALCOTT. 295
ribs are large on a prominent mesial fold; in most young- shells thesinus and fold are inconspicuous, the convexity is ver}' moderate andthe shell smooth; nearly all the characters of the adult are missing.A group of young shells from Honej^ Creek shows only the smooth,slightly convex forms with onl\^ slight ventral sinus and dorsal fold.One larger shell associated with the young shells has a relatively deepsinus and a trace of a plication.Formation and locality.?Upper Cambrian. Cold Creek Canyonand Honey Creek. Burnet County. Texas.Genus POLYTOECHIA Hall and Clarke.Polytoechia Hall and Clarke, Pal. N. Y., VIII, 1892, Pt. 1, p. 239, pi. vii a,figs. 26-30.Original diagnosis.? Shell small, t^ubtrihedral in contour. Hinge line straight,about equaling the diameter of the shell. Pedicle [ventral] valve with a high,nearly vertical cardinal area marked with oblique striations parallel to the lateralmargins. Delthyrium covered bj' a narrow, convex plate; the presence of a foramennot determined. On the interior the <lental lamellfe are widely separated anddescend along the umbonal cavity for a short distance vertically, thence bendingsharply inward and meeting at a low angle in the median line, thus forming, withthe deltidium, a conspicuous subrostral vault. This inner spoon-shaped plate,spondylium, is supported by a stout median septum, and two smaller lateral septa,which meet at the lines of angulation; the former of these extends for the entirelength of the plate, while the latter is free from the accessory septa near its anterioredge. The umbonal cavity of the valve is thus divided into five chambers, and inthe lateral chambers there is still another septum, lower than the rest and notextending to the spondylium. The brachial [dorsal] valve is shallow and depressed-convex, with a narrow cardinal area. The delthyrium is very broad, with a par-tially developed covering, the dental sockets are widely separated, the crural platesnarrow and nearly parallel to the hinge line. The cardinal process is simple, linearand quite prominent, and at its union with the crural plates is a subtriangular thick-ening which is supported by a low median septum. Surface covered witli fine, ele-vated radiating stria?, without evidence of median fold and sinus.Type.?Hemipronites apicalis, Whitfield.Ohservations.?This genus is known only in the Lower Ordovicianstrata of Vermont and Montana. The tj^pe species is described ashaving a convex deltidium covering the delthyrium of the ventTal valve;this character and the additional septa supporting the spondjdium andcruralium are the distinguishing characters between it and Syntrojjhia.There is still less difference from Clitariihonites^ as in the latter theconvex deltidium is present. It is quite probable that representativesof the genus will be found in the Upper Caml^rian formations whenthey are searched more thoroughly.POLYTOECHIA ? MONTANENSIS, new species.This shell was placed with Camerella calcifera until sections weremade showing the numerous septa supporting the spondylium andcruraliimi. In general form it is close to Syntrophia rotundata^ dif-fering in the numerous supporting septa of the spondylium which
296 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvni.divide the umbonal cavity into fine chambers. The material availablefor .study does not show the area in very g-ood preservation; a delthy-rium exists in the area of the ventral valve which is all that can be said.This species appears to be a direct descendant of the smooth, convexforms of Si/7itropMa like ^S'. rotundata.Formation and locality.?Lower Ordovician. Limestone east sideof Gallatin River a))ove Gallatin City, Montana.SWANTONIA, ne\^^ genus.The description of the type species includes that of the genus, asthere is only one other species now referred to the genus and that isvery imperfectly known.Type.? Camarella antiqua., Billings.SWANTONIA ANTIQUATA, Billings.CamereUa antigiiata BihhiyiCiS, Pal. Fogs., I, 1861, p. 10, iig. 13.Camerella antujuata Billings, Geol. Vermont, II, 1861, p. 949, tig. 353.Camarella antiquata Billings, Geol. Canada, 1863, p. 284, fig. 290.Camarella antiquata Walcott, Bull. U. S. Geol. Survey, No. 30, 1886, p. 122,pi. VII, fig. 8.Camarella. antiquata Walcott, Tenth Ann. Kept. U. S. Geol. Survey, 1891,p. 613, pi. Lxxii, fig. 3.Camarella? aidiquata Hall and Clarke, Pal. New York, VIII, 1893, Pt. 2,p. 220.Protorliyncha ? antiquata. Schuciiert, Bull. I". S. Geol. Survey, 1897, No. 87,p. 334.Ventral valve ovate, moderateh" convex ; apex pointed and incurvedover the area nearly to the plane of the margins of the valve; surfacemarked by from 8 to 12 or more rounded ribs that extend back welltoward the apex; a slight flattening of the median portion suggeststhat a shallow median sinus may be found on old shells. The shellillustrated has a length and width of 11 mm.A cast of the interior of a ventral valve shows no traces of musclescars or vascular markings ; two strong teeth are indicated, also anarrow, strong, concave shelf or area ; the area shelf is free from con-tact with the bottom of the valve, a recess or chamber existingbeneath it.()hserv(ttion.'<.?The area or shelf may ])e considered a short, freespondylium, corresponding to the short spondylium of Camarella vol-horthi as illustrated by Hall and Clarke.*^ It differs from the latter inthe absence of a supporting median septum.Swantonia is closely related to CariiareUa., but it differs in theabsence of a supporting median septum beneath the spond3dium of theventral valve. No specimens of the dorsal valve have been observed.
"Pal. New York, VIII, Pt. 2, pi. lxii, fig. 18.
NO. 1396. CAMBRIAN BRACHIOPODA?WALCOTT. 297Formation and locality.?Lower Cambrian, in sandy shales withOlenellus thompsoni, Kutorgina ci.ugidata, and IpJildea lahrado7'ica.One and a half to 2 miles east of Swanton, Vermont.SWANTONIA WEEKSI, new species.This shell has the g-eneral form of Sioantonla aidupuita^ but the ribsare finer, more numerous, and crossed b}^ line, sharp concentric stria?.Only the exterior of the ventral valv^e appears to ])e represented in thecollection made by Mr. F. B. Weeks.Formation and locality.?Lower Caml)rian. In an arg-illaceousshale with fragments of Olenellus, Kutorgina ,'<j)mosa., etc. Threemiles north of Volcaldi Spring, or 4 miles northwest of Drinkwatermine, Silver Peak Distric^t, Nevada.OBOLELLA ASIATICA, new species.General form broad, oval, with the ventral valve showing- a tend-ency to become bluntly acuminate. Valves gently convex. Surfaceof shell marked by concentric, raised lines of growth that formthe front edge of narrow lamella? of varying width; the raised linesare highest on their front side, which gives an imbricated appearanceto the surface; fine concentric stride occur on the interspaces betweenthe raised lines. Shell strong, calcareous.The specimens occur in a compact, bluish-gray oolitic limestone.None of them show the area or interior of the valves. The referenceto Obolella is based on the general form and calcareous shell. Theshells vary in size from 3 mm. to .5 mm.Oholella asiatlca may be compared with young shells of (). cras.m.Its broadl}^ elliptical form and slight convexity distinguish it fromother species of the genus.It may be that if material is found showing the interior of the valvesthe generic reference will be changed; but with the data now avail-able the reference is to Obolella.The geological horizon is in some doubt as the specimens werefound in a block of river drift limestone. The associated fragmentsof trilobites are two indefinite for determination. Obolella is a LowerCambrian genus as far as known, and other blocks of river drift lime-stone at the same locality contained fragments of Olefiellu,s., so thereference of the species is made to the Lower Cambrian.Formation and locality.?Lower Cambrian. River drift on the LanHo River, 1 mile south of Chen Ping Hsien, Southern Shensi, China.Collection of Bailey Willis and Eliot T. Blackwelder, Carnegie Insti-tution of Washington, expedition to China.
298 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.ACROTRETA ATTENUATA Meek.Acrotreta atleimata Meek, Sixth Ann. Rep. U. S. Geol. Hur. Terr., 1873, p. 463.A'Tofrt'ta gemma Walcott, Monog. U. S. Geol. 8nr. VIII, 1884, p. 17; Bull.V. S. Geol. Sur. No. 30, 1886, p. 98; Monog. U. S. Geol. Sur., XXXII, 1899.rt. 2, p. 449.The species is cliai'acterizod by its elevated ventral valve and narrow,incurved false area. Some of the forms of A. idahoenms alta looklike A. ((tte)ti((ita, but the false area is different. ^1. l-utorgal has asomewhat similar false area and elevation, but it is a less robust shelland the apex of the ventral valve is nearer the posterior margin. Thereference to .1. (/etm/taiH explained under the description of the genus.A shell with a distinctly marked false pedicle groove in the ventralvalve, occurs in the Bathynrli^cim >i^heelerl zone of the Middle Cambrianof Utah that shows tine interiors of both valves. The interiors of theventral valve are nuich like those of A. hutoryal.Formation and loadlty.?Middle Cambrian. Flathead terrane.Valley of East Gallatin River near Hillsdale. North of GallatinRiver. Base of limestone series resting on Flathead shales, BeaverCreek, miles north of York, Big Belt Mountains, Montana, Ondivide at head of Sheep Creek near the north end of Teton range,Wyoming. South slopes of Marjum Pass, west of divide, Houserange, Utah. Above Bathyiiriscus tnheelert zone 2i miles east ofAntelope Springs, House range, Utah.Upper Cambrian. In the Hamburg shale, a little south of theHamburg mine. Eureka district, Nevada.ACROTRETA ATTENUATA, variety.'A shell with a distinctly marked false area is separated as a varietyof .1. atti'iniafa. It is associated Avith the type specimens in the eastGallatin Valley. ACROTRETA BISECTA Matthew.Acrohria halleyl Matthew? Trans. Roy. Soc. Canada, IX, 1892, j). 43, pi. xn,lig. 7(1.Acrofreta Insecia Matthew, Bull. Nat. Hist. Soc. New Brunswick. IV, 1901, p.275, pi. V, figs. 5a-g; IV, 1902, pi, v, p. 394; pi. xvi, figs. 2, 2a-g.Acrotirta xlpo Matthew, Bull. Nat. Hist. Soc. New Brunswick, IV, 1902, Ft. 5,]). 406, pi. XVIII, figs. 1 and 2.Acrofrctu mpo Matthew, Geol. Sur. Canada, Rep. C'ambrian rocks. Cape Breton,1903, p. 185, pi. XVIII, figs. 1 and 2.Acruhrt(( hi>feci(( Matthew, Geol. Sur. Canada, Rep. Cambrian rocks, CapeBreton, 1903, \>. 186, ])1. \i, figs. 5a-g.Nearly all the ventral valves of this species arfe more or less com-j)ressed in the shale, thus decreasing the true elevation. Mr. Matthewillustrates a pointed, high ventral valve, but does not state whethertlie tio-ure is diaii'ramatic. Some of the casts in the shale indicate a
NO. 1395. CAMBEIAy BRACHIOPODA?WALCOTT. 299
.sharph' conical ventral valve. When the apex is broken off the castof a median apical callosity is seeiip/with the base of the cast of amedium-sized foraminal tube. Th^ardinal scars are small and nearlyconcealed by the cast of the strong- main vascular sinuses. There isconsiderable range of variation in the size and lenglh of the medianridg-e of the dorsal valve. One specimen shows a strong median ridge,cardinal and central scars, and deeply excavated false deltidium. Sur-face marked by tine concentric striie and lines of growth and very fineundulating striae, that give the concentric stride a fretted appearancewhen examined l)y a strong lens.The most nearly related species appears to be A. sahrinm of theShineton shales. Dr. Cr. F. Matthew has described a shell as Acrotretaslpo that occurs with the ^Vsaphellus fauna, I am unable to detect anyspecifi(; difi'erences l>etween it and A. hisecta from the same area.Formation and localifij.?ITpper Cambrian. Barrachois Glen, 4miles south of Little Bras D'Or Lake, Cape Breton. Mr. Matthew'stypes came from McLeod Brook, Cape Breton, Nova Scotia, and healso identifies it from division C, 3c., at Navy Island, St. John Harbor,New Brunswick. Mr. S. Ward Loper found many specimens at sev-eral horizons in the shales on both sides of the Barrachois River nearthe Boisdale road and for some distance north, also on the east branchof the Barrachois River, (kpe Breton, Nova Scotia. On the westbank it is associated with AmpJtellv.s honiphrayi var. as identified byDr. (t. F. Matthew.ACROTRETA? CANCELLATA, new species.The only specimen of this species in the collection has more theform of Iphidea than Acrotreta. In its overhanging false area it sug-gests Aet'othi/ra. Whatever the genus may be to which it belongs,its cancellated surface serves to distinguish it from forms to which itmight otherwise be compared. This surface is formed by very fine,raised, concentric lines or ridges of growth, crossed b}' sharp radiat-ing lines which are seen only between the concentric lines.Formation and locality.?Ordovician Pogonip limestone, RoundTop Mountain, Eureka District, Nevada.ACROTRETA EGGEGRUNDENSIS Wiman.Acrotreta eggegrundeni^iii Wimax, Bull. Ueol. Institute, Upsala, No. 2, VI, 1903,Pt. 1; Studien Nordljaltisohe Silurgebiet, p. 55, pi. ii, figs. 23-29.This species is of a characteristic Middle Cambrian type of Acro-treta, represented in America by A. Idahoensh and A. hutorgal. Thesurface is marked l)v unusually strong lines and ridges of growth andthe false area is well defined. It is quite distinct from other speciesof the genus in European formations.
300 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.Fovhiiition and locality.?Middle ? Cambrian, Coarse grained, some-what friable, glauconitic sandstone. Drift bowlder No. 3 on Egge-grund Island, North Baltic region, Sweden.For note on the geological horizon se(^ description of O. ( Westonia)bottnlaa. ACROTRETA EMMONSI, new species.Only the interiors of the two valves are known of this species. Oneof them shows the distinct character of the vascular markings andmuscle scars. The only shell with which it can be compared is thedorsal valve of Acrotreta idahoensis. At first sight I was inclined torefei' this shell to Oholella, but its corneous test, cardinal muscle scars,and absence of area of the Oholella tj^pe, prevented. Fragments ofOlendlax occur in the layer of limestone from which the specimenswere obtained.The specific name is given in memory of Dr. Ebenezer Emmons,who studied and wrote of the Bald Mountain section.Formation and locality.-?Lower Cambrian. Limestone interbeddedin shales on upper part of the west slope of Bald Mountain, townshipof Greenwich, Washington County, New York,ACROTRETA LIANI, new species.Shell small, about 1.5 nun, in diameter; outline of aperature sub-circular, the posterior side being- slightly transverse. Ventral valveconical with the apex a little in advance of the posterior margin;false area indefinite, except for a rather strong, flat furrow thatextends from the apex to the margin; the elevation of the valve isabout two-thirds its diameter at its aperature. Dorsal valve slightlyconvex, apex marginal. Surface of shell marked by fine, concentricstriie and lines of growth that on the dorsal valve tend to form lowridges toward the outer margins.Observations.?This species is the representative of the AmericanAcrotreta idahoensis sulcata. It has the same type of false area, andthe ventral valve is of average height. The specific name is given inrecognition of Lian, Mr. Willis's faithful Chinese interpreter.Formation and locality.?Middle Cambrian. Chang Hsia limestonein upper oolitic portion, Chang Hsia, Shantung, China.Collections of Mr. Eliot Blackwelder, Carnegie Institution of Wash-ington, expedition to China.ACROTRETA NEBOENSIS, new species.This is one of the Acrotrda. idahoensis forms of the genus. Theventral valve is moderately elevated, the apex projecting slightly overthe nearly vertical false area. The latter is marked midway by a verynari'ow false pedicle furrow.
NO. 1395. CAMBRIAN BRACHTOPODA?WALCOTT. 301The transverse dorsal valve has a strong median depression, w hichstarts on the umbo and widens out rapidly toward the front. The sur-face of the shell is marked by concentric ridges and lines of growthand very line concentric strife.This species differs from other described forms in the strong mediandepression of the dorsal valve.Form at!on and locality.?Middle Cambrian. Limestone above <:\ iiart-zite, Mount Nebo Canyon, 8 miles southeast of Mona, Utah.ACROTRETA NOX, new species.This minute shell, 1 mm. in length, is characterized bv its low ven-tral valve, nipple- like apex, and apparentl}^ smooth surface.Formation and locality.?Upper Cambrian. Argillaceous shales inSt. Croix sandstone, 8 miles east of Baraboo, Wisconsin.ACROTRETA PACIFICA, new species.Ventral valve a high cone, with the apex a little in advance of theposterior margin: l)ase circular, with the exception of a slight flatten-ing on the posterior side; apex acute and pointing upward; false areaonly a slight flattening of the shell from the apex to the margin. Thelargest ventral valve has a diameter and height of about 1.5 mm. Sur-face marked b}' tine concentric stria? that continue without noticeabledeflection across the false area.Ohservations.?Onl}^ two specimens of the ventral valve of thisspecies occur in the collection. One of these has a slightly transverse,broadh" oval base, and a more definite false area. The species is closelyrelated to Acrotreta idahoensis <dta^ except that the ventral valve is notquite as elevated.Formation and locality.?Middle Cambrian. Chang Hsia limestoneat Yen Chuang and 3^ miles southwest of Yen Chuang; 3 miles south-west of Yen Chuang in limestone nodules at base of green shale phaseof the Chang llsia oolitic formation; Shantung, China.Collections of Mr. Eliot Blackwelder, Carnegie Institution of Wash-ington, expedition to China.ACROTRETA SHANTUNGENSIS, new species.Shell small. Ventral valve a low cone with the apex a little forwardof the posterior margin, Avhich is slightly flattened; apex minute,directed backward and projecting slightly over the faintly definedfalse area. The cast of the interior shows that the apical callosit}^ wasrather large and the main vascular sinuses well defined on each side ofit; the cardinal scars ai"e small and not prominent.Dorsal valve slightly convex; apex marginal; surface marked by arather broad shallow median depression that begins on the umbo andgradually widens toward the front margin. The interior of the dorsalProc. N. il. vol. xxviii?04-. 20
302 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.valve has a strong median ridge extending from the posterior margintwo-thirds the distance toward the front. A small elev^ated cardinalscar occurs on each side of the median ridge a little in advance of theposterior margin. Main vascular sinuses rather strong; they startbeneath the apex and extend forward a short distance from the outerlateral margin of the shell. Surface marked V)v hue concentric striaeand lines of growth.Ohservations,?This shell in size and general form is closely relatedto Acrotreta rat cvo.hcopica of the Middle Cambrian fauna of the UnitedStates. It occurs quite abundantly in a chocolate-colored limestoneassociated with Oholnn {Llngnlella) rhlnriiHis.Fonnation and locality.?Middle Cambrian. Chang Hsia limestone.Yen Chuang and 2^ miles south of Yen Chuang, Shantung, China.A shell apparently identical with ^1. !^hantungens!s was collectedfrom a line-grained ])luish-black limestone river drift block 1 milesouth of Chen Ping Hsien, on the Lan Ho River.Collections of Mr. Bailey Willis and Mr. Eliot Blackwelder, CarnegieInstitution of Washington, expedition to China.ACROTRETA SPINOSA, new species.The general form of this shell is much like that of Acrotreta idaho-ohsin. It differs in having a straighter posterior margin. The maincharacter of the species is the spinose outer surface. The surface ismarked by tine concentric lines of growth at irregular intervals, withnumerous, very tine, thread-like stria3 between. On some shellsradiating, more or less irregular, tine, rounded ridges occur that areformed by the elevated elongate spine bases. When these elongatebases are irregularly arranged, the radiating ridges are not present.Owing to their minute size the spinules are rarely seen.Formation and locaUii/.?Upper Cambrian, Hamburgh shale. Ham-burgh Ridge; east side of Sierra Canyon opposite Pinnacle Peak andalso opposite the Jackson Mine, Eureka District. Nevada.ACROTRETA UPLANDENSIS Wiman.Acrotreta Hplandensig Wimas, Bull. Geol. Institute, Upsala, No. 2, YI, 1903-Pt. 1 ; Studien Nordbaltische Silurgebiet, p. 54, pi. ii. figs. 15-18.This species recalls at once A. idaJioensis sulcata. It differs fromit in having a broader false area. The surface is marked b}^ tinethread-like stria? that cross the false area and false pedicle groove.Formation and localitii.?Middle ? Cambrian. Gray bituminoussandstone in drift bowlder No. 2 on Biludden Island. Also in glau-conitic sandstone, bowlder No. 1, at Hoganas Commune of Borstil,Sweden.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 303ACROTRETA UPLANDICA LIMONENSIS Wiman.Acrotrela uplandka Umoneni^ia Wi.max, Bull. Geol. Institute, U]>sala, No. 2, YI,1903, Pt. 1; Studien Nordbaltische Silurgebiet, p. 54, pi. ii, tigs. 19-22.Doctor Wiman states that this species is quite like A. uplandlca^hut lower, as the heio-ht is only one-third of the diameter. It is soclose in all other respects that I do not think that more than a varietalvalue should be given to the ditierences mentioned.Forinatwn and Jocrdity.?Middle ? Cambrian. Bluish calcaneoussandstone. Drift bowlder, Limon Island, Gefle Bay, Sweden.ACROTHYRA MINOR, new species.This species diti'ers from others referred to the genus by its broadform and very strong- vascular sinuses. The elevated callus betweenthe sinuses is high and oval in outline, somewhat like that of Acrotretainflata. It ma}" be that this species l)elongs to a different genus, butwith the material available for study it is referred to Acrothyra onaccount of its low, overhanging false area and elongate visceral area.Foi'inatlon (Old locality.?Middle Cambrian. Two miles southeastof Malad City, Idaho.ACROTHELE (?) MINUTA, new species.Shell minute, 1.5 mm. in diameter, subcinadar in outline, gentlyconvex, with a slight median depression from the uml)o to the anteriormargin; back of the uml)0 there is a sharp median depression betweenminute ridges, on each of wdiich there are two points or nipples.Surface marked by line concentric stride. Substance of shell appar-ently phosphatic.This interesting little species is represented by a single specimen.The generic reference is somew^hat doubtful.Fonnathni aad locality.?Middle Cambrian. Chang' Hsia limestone.Two and one-half miles southwest of Yen Chuang, Shantung, China.Collection of Eliot Blackwelder, Carnegie Institution of Washing-ton, expedition to China.ACROTHELE RARUS, new species.Of this shell only the interiors of the valves are known. Shells ofaverage size are about 3.5 mm. in diameter. The outline of the valveis subcircular, the transverse diameter being slightly more than thelength of the valve. The interior of the ventral valve shows that thevalve was moderately convex with a perforated apex about one-half amillimeter from the posteric r margin. A short, broad median ridgeextends for a short distance in front of the foramina! opening andshort, narrow ridges extend obliquely forward from each side of theopening. What may be lateral muscle scars occur close to the postero-lateral margins. In the dorsal valve a strong median ridge extends
304 rBOCEEDINOS OF THE NATIONAL MUSEUM. vol. xxviii.from the posterior niarg-iii to the center of the valve; this ridge isanguhir at the summit and broadest toward its anterior end. A vascu-lar sinus starts on each side of the base of the median ridge andextends obli(|ueh' forward.The dark interior surface of the valves is marked by concentric linesthat give a somewhat laminated appearance to the surface. From themanner in which the shell adheres to the limestone matrix, it is prob-able that its outer surface is roughened hy raised lines, somewhat ason Acrof/u'h' auhsldna.The data for comparison of this species with described species fromAmerica and Europe are too limited to bo of value. A comparison withAcrothele {inohergid) (jrani(J(d((^ Rodlich, of the Salt Range, India,shows a strong similarity in the interiors of the dorsal valves; but 1do not think it is probable that the two forms arc specitically identical,as the interiors of the valves of several species of Acrothele appearvery uuich alike.Formation and locality.?Middle Cambrian, Chang Hsia limestone.Three miles south of Kao Chia Pu, Shantung, China.Collected by Mr. Eliot Blackwelder, of the Carnegie Institution ofWashington, expedition to China.IPHIDELLA, new genus.Iplddea Billings, Can. Nat., new ser., YI, 1872, j). 477, lig. 13, and of Authors.?Not Iphldea Bayley, 1865.For synonomy and description of Iphidea=lphidella, see Proc. U. S.Nat. Mus., XIX. 1897, p. 707.IPHIDELLA MAJOR, new species.Ventral valve subconical, with the apex slightl}- in front of theposterior margin. A minute beak appears to incurve over the pseu-dodeltidium. Cardinal slope rather abruptly rounded so as to indi-cate a rather narrow area. Pseudodeltidium l)road, convex, with itslower margin arched so as to leave a space between it and the hingeline of the shell. Dorsal valve slightly convex, with a narrow areaand broad, apparenth' open delthyrium.Surface, as far as can be determined from the badly preservedmaterial, marked by very tine concentric striie.The material representing this SY)ecies is more or less compressedand distorted in the argillaceous shales in which it occurs. In generalform it is not unlike that of /. lahradorlca, but it differs in its nearlysmooth surface and the y^osition of the apex. From /. .^oij^erha itdiffers in its much greater size, although resembling it in the narrowand perfectly deiined area of the ventral valve, and the large, broad,convex pseudodeltidium.Formation and locality.?Lower Cambrian. Argillaceous shales, 4miles south of Helena. Slielbv Countv. Alabama.
NO. 1395. CAMBRIAN BRACniOPODA?WALCOTT. 305IPHIDELLA NISUS, new species.Ventral valve rather low, with the apex overhanging' the posteriormargin. Surface marked by very fine lines of growth with still linerbands of stria^ between them. About 10 very tine, radiating i4dgesextend from near the apex to the front and lateral margins.This little shell is represented by a single specimen of the ventralvalve from the conglomerate limestones near Bic. The associated faunaincluded fragments of Olenellus.I was at first inclined to refer this shell to /. sculpt'dh or I. jjeall; butthe overhanging apex and strongly marked surface, and the fact thatthere is an interval of :?,000 miles between the species, led me to sepa-rate them. Stratigraphically the two latter species occur in the MiddleCambrian and nhm in the Lower Cambrian. I think the two formsforms should not be included in one species.Forriiation and locality.?Lower Cambrian. In a bowlder of thelimestone, 2 miles w^est of Bic Station, Province of Quebec, Canada.IPHIDELLA, species undetermined. ^ , ,< -^ ', 3^^Iphidea, sp. undet. Walcott, Mong. U. S. Geol. 8ur., XXXII, 1899, p. 449, pi.LX, fig. 6.Dorsal valve, semicircular, slightly convex. Hinge line somewhatshorter than the wndth of the shell below; nearly straight, the rostralangle about 180?. Beak small, not elevated. Surface ornamentationconsists of extremely tine radiating and undulating concentric stria?that can be seen in detail only with a strong magnifying glass. Shellsubstance horny.This form is associated with /. sculj^>t!lls and, judging from externalcharacters, is closely related to it. The surface ornamention is of thesame character, and in the absence of the ventral valve it is difficult todistingiash an}- specitic characters on which to base a new species,although the shell is much larger than that of typical I. sculptilis.Forination and locality.?Middle Cambrian. Flathead terrane (low-est fossiliferous bed); Crowfoot section, (xallatin range, YellowstoneNational Park, Wyoming.IPHIDELLA LABRADORICA ORIENTALIS, new variety.Only one dorsal valve of this shell occurs in the collection. Its gen-eral form and surface characters are very much like those of I_phideHalahradorica swantonensis. The varietal name is given more on accountof the fact that this shell occurs in China and the variety mcantonensison the eastern side of the North American continent than from anymarked differences between the shells from the two localities. It maybe that with a good series of shells from China differences would befound that are not to be determined with only the single shell forcomparison.
306 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.Formation mid locality.?Middle ('and)riaii. Chang" Hsia ooliticlimestone, Yen Chuang-, Shantung, China.Collections of Mr. Eliot Blackwelder, Carnegie Institution of Wash-ington, Expedition to China.IPHIDELLA LABRADORICA UTAHENSIS, new variety.The general form of this variety is nuich like that of IpludeUa lahra-dorlea. It differs from it in the tine thread-like concentric striae ofthe outer sui-face, in this I'espect approaching L aJahonaevsls and/. KaperlKi.Foniudioa and loc<d!ty.?^liddle Cambrian. Concretionary lime-stone above ({uartzitic sandstone, Ophir (!ity, 0(iuirrh Range, Utah.IPHIDELLA PANNULA MALADENSIS, new variety.IPHIDELLA PANNULA OPHIRENSIS, new variety.In collections from the Middle Caml)rian limestones of northernUtah and southern Idaho, material has been selected for illustrationwhich represents variety of form and surface markings of IjyJiideUapannula that might be given specific names were it not for the inter-mediate phases which occur at the same locality with the varieties.The specimens from near Maiad Cit}'. Idaho, show a wide variationin outline and surface. Another series from near Ophir Cit}', Utah,illustrate the entire evolution of the ''pannula'"' type of surface, fromthe concentric striic to the tine network of oblique, raised linesdividing the surface into minute, diamond-shaped depressions. Insome examples the ridg-es are so sharp iuid clear that the surface hasa honeycomb-like appearance.For convenience of reference the species might be subdivided intothree varieties :Vdvh'iij A.?Surface with pore-like pits, formed l>y oblitjuely crossing, elevatedHues.Variety B.?Surface with elevated, sharj) ridges that give it an irregular honeycouib-like appearance.Varietij <_'.?Surface formed by raised, concentric lines and ridges that inosculateand become more and more irregular until a tyjiical surface rejjivsented l)y varietyA is developed.The first variety. A, is typical of the species. For the secondvariety the name ni(d<idenKls is proposed, and for the third variet}"the term ophirensis.Genus KUTORGINA Billings.Kutorgrna Billings, l*amphlet; and Geol. Vermont, II, 1S61, p. 948, footnote,figs. 347-349; (leol. Surv. Canada, Pal. Foss., I, 1865, p. 9, figs. 8-10.?David-son, Brit. Foss. Brach., Ill, 1871, p. 342.?Dall, Bull. U. S. Nat. Museum,VIII, 1877, p. 40.?Walcott, Bull. U. S. Geol. Survey, No. 30, 1886, p. 101.?Beecher, Am. Jour. Sci., 3d ser., XLI, 1891, p. 345.
?
Hall and Clarke,Pal. New York, VIII, 1892, Pt. 1. pp. 90, 1()6, 183; Eleventh Ann. Kept.New York State Geologist, 1894, i>. 247, i)l. iv, figs. 11-13.
NO. 1395. CAMBRIAN BRACHIOFODA?WALCOTT. 307Mr. l?illiiigs proposed the genus Kutonjiixi in a footnote acconi-pan34ng the description of the type species K. clmjuhitd. He says:Since the above was written I have examined many cast.s of the interior of thisspecies, and am inclined to the opinion that it is generically distinct from OboleUachwiixitJca. From the very considerable elevation of- the beak the dorsal valve musthave an area and probably a foramen. In one specimen there are two large ovalimpressions faintly impresse<l, but still distinctly visible. There is no trace of thelateral scars; and tlie form, notwithstanding the characters of the surface, conveysthe idea of an Orthisina. Should, upon further examination, my suspicions turn outto be well founded, I shall call the genus Kulorgimi, after the celebrated Europeannaturalist, Kutorga.From our present information of the genus the following diagnosisis prepared:Shells inequivalve, transverse or elongated. Ventral valve convex,with apex marginal or incurved over the pseudoarea. Cardinal arearudimentary, without delthyrium or well-detined pseudodeltidium.The latter usually extends one-half the distance from the apex to theplane of the posterior margins of the valve. Interior of the ventralvalve with well-detined main vascular sinuses, with a visceral area])etween the sinuses. Dorsal valve flat or slightly convex, rising to asmall, elevated um])o; apex marginal and usually pointing upward;cardinal area short, rudimentary, and without well-defined pseudodel-tidium. Interior of ventral Naive with median septum between thecentral and posterior lateral muscle scars.Ohservationa.?The short cardinal areas of the valves leave a broadopen space between them for the passage of the pedicle. The areasare more than the i-eflected posterior margins of the valves, as theyhave transverse lines of g*rowth and a suggestion of a pseudodeltidium.These features are more rudimentary than in Iphidella. Kutorginaincludes the larger calcareous shells, and Tphidella the somewhat morespecialized, smaller, corneous shells. The exterior form of the valvesof Kutorgina suggest NtHitsia festinata^ with which the type species,K. cmgiiJafa^ is associated in Vermont and at Bic Harbor.The following species are now referred to Kutorgina:K cingidata Billings, K. j>enigata Walcott, K. mrdiniaensis Wal-cott, and K. sp. luidet. All the species are from the lower Cambrianhorizon, with the possible exception of K. sardmiaensis.Of species heretofore referred to the genus the following dispositionis made:I\. Jidjradorlca BiW'mgs= Ip/i Idella.K labradorica siaantonensii<= Tphidella.K. latourensis Matthew= P/v^/cr;'////,9.K. oninutisHima. Hall and V^l^hW^Ad^ IpJddella sculptilis.K. pannula White= Iphidella.K. 'prospecteni<is Waleott= Ijdu'della.
808 PROCEEDINGS OF THE NATIONAL MUSEUM. voi.. xxvm.IC srulptilis Meek= I/>///'</d/((.K. Htissingensls D vv ight= Tphidella.K. lohitfieldi W'A\co{i? BUUngseUa.KUTORGINA CINGULATA Billings.Oholella {KnlorgliKi) cliigulata Billincs, Geol. Vermont, H, ISfil, p. 94S, figs.347-349; Pal. Fohs., I, p. 8, figs. 8-10.Oholelld. chrKjnlaia Bi lungs, Geol. Canada, 1S()3, ji. 284, fig. 287.OholeUaf phUlipd Holl, Quart. Jour. Geol. Sor., XXI, 18(54, i>i?. 101, 102, figs.10a, 1).Kntorii'iiKi cingulata D.widson, (reel. Mag., V, 1868, p. 312, ])1. xvi, tig. 10;Brit. Hil. Brachiopoda, 1871, p. 342, i)l. l, fig. 25.KuUmjina cliK/vlatd Walcott, Bull. V. S. Geol. Survey, 1886, p. 102, pi. ix,fig. 1. ^Kutorg'ma eingnlafa Beectier, Anier. Jour. Rei., 3d ser. , XLI, 1891, p. 345.Kntorgina cingulata W.vlcott, Tenth A.nn. Rept. U. S. Geol. Survey, 1891, p.609, pi. Lxix, fig. 1.Kutorg'ma cingulata II.vll and Clarke, Pal. Xew York, VIII, 1892, Pt. 1, p. 92,figs. 47-49; pi. iv, figs. 10-17.Kutorg'ma cingulata von Toll, Mem. de I'Acad. Imp. des Sci. de St. Peters-burg, VIII ser., 1899. I, Beit, zur Kenntniss des Siberischen Cambrium, p.26, pi. I, fig. 28.General form transversely or lonoitudinally oval; biconvex, with theventral much more convex than the dorsal valve. Surface marked byconcentric lines and ridges of growth and the edges by imbricatinglamella^ of growth. Shell substance calcareous and fibrous. The shellis formed of a thin, dark, compact outer layer and a thick, fibrous,calcareous inner layer. It is possible that the thin outer layer is chi-tinous, but it does not appear to be so. The L'Anse au Loup and BicHarbor shells average about 15 mm. long by 17 mm. in width. Atthe Swanton locality, in Vermont, ventral valves occur 24 mm. inheight and with a width of 30 mm., and one large dorsal valve is 20mm, in length with a width of 30 mm.Ventral valve in young shells moderately convex, becoming moreand more convex with increase in size and age. In young shells theslope from the front margin to the apex is nearly straight, and theapex terminates at the posterior edge of the valve above the more orless elevated pseudodeltidium. In old shells the curvature from thefront to the apex is nearly a semicircle, and the apex terminates ina pointed beak overhanging the pseudodeltidium. A mesial sinus ofvarying strength occurs on many shells, and in others it is entirelyabsent. The pseudo area is concave on the outer parts. Toward thecenter it becomes slightly flattened or convex and thus forms a veryrudimentary pseudodeltidium. It extends beneath the apex at anangle of about 4.5? to the plane of the margins of the valve. Thecentral portion of the pseudo area extends about one-half the distancefrom the apex to the plane of the valve and forms a gentle arch.A partially exfoliated shell shows four dark lines radiating forward
-NO. 1395. CAMBRIAN BRACHIOPODA? WALCOTT. 309from the umbo and two near the sides that may have sometliing- to dowith the muscle scars or vascular sinuses. 1 thought so in ISSG," butam not sufficiently confident of it now to state it as a settled conclu-sion. Fine punct* occur on the inner layer of the shell; also numer-ous radiating lines about one-half a millimeter apart.Dorsal valve gently convex in young shells. With increase in sizethe umbo becomes more elevated and the apex })oints upward or termi-nates at the union of the pseudo area and the upward slope of the shellon the umbo. In some shells there is a tendency for the valve tobecome slightly concave in the space between the margins and theelevated umbo. The pseudo area of the valve is narrow and with littlecharacter; on some shells it slopes beneath the apex, and on others itslopes backw^ard, forming a low angle with the surface oi the valve.The interior of the dorsal valve shows a median septum, with twocentral scars, and the anterior lateral scars. Numerous small vascularcanals radiate from central concave area toward the tiattened anteriorand lateral half of the valve. A cast of the interior shows two vascularcanals radiating forward from near the apex. Radiating lines occuron the interior of the same character as those of the ventral valve.Ohservations.?Since writing on this species in 188(3 I have collectedipecimens showing the character of the pseudo areas of the valves, andalso obtained further information relative to the interior of the dorsalvalve. The rudimentary or pseudo areas are less advanced in develop-ment than those of Iphidella^ and the muscle scars of the dorsal valveare much like those of OholeUa and Oholns.The specimens from Bic Harbor and east of Swanton, Vermont, arebetter than those from the type locality at L'Anse au Loup. Many ofthe V^ermont shells are larger and more fully developed, l)ut specimensof the same size as those from L'Anse au Loup and Bic Harbor areidentical in the characters available for comparison.Formation and locality.?Lower Cambrian. L'Anse au Loup lime-stone with OlenelluH thoiupsonlvit L'Anse au Loup, on the north shoreof the straits of Belle Isle, Labrador. In bowlders of limestone con-taining fragments of Olenellus, in Cambrian conglomerate, at EastPoint, Bic Harbor, Province of Quebec, Canada. The species isabundant in lenticular masses of limestone intercalated in argillaceousand arenaceous shales carrying OleneUuH tliom,j>soni on the Bullardfarm, about two miles east of Swan ton, Vermont.Dr. Eduard von ToU^^ identities and illustrates as Kntorgina cin-(juhda Billings a dorsal valve that occurs with other forms that may bereferred to the Lower Cambrian fauna of the Cambrian of Siberia.Locality.?Near the Tschurskaja Station, on the Lena.
?Bull. U. S. Geol. Survey, No. 30, p. 103.^Beitrage zu Kenntniss des Sibiriseheii Cambrium, I. M^m. de I'Acad. Imp. deaSci. de St. Petersbourg, VIII ser., 1899, pp. 26-27.
310 PllOCEKDlNGS OF THE NATIONAL MUSEUM. vol. xxviii.KUTORGINA PERUGATA, new species.GenGrul t'(jnn ovate, biconvex. Surface marked by concentric linesof growth and more or less strong* concentric corrugations; the outersurface is ornamented by a tine network of ol)lique, depressed lines,that leave minute rhomboidal elevations ))etween them that look likefine i)apillie under a moderately strong magnifier, and the cast of thesurface has much the same appearance in a transverse light. Shellsul)stance calcareous.A large ventral valve has a length of li mm. ; width. 16 mm. Adorsal valve 11 mm. in length has a width of 11 mm.The ventral valve is strongly convex in adult shells, with the highestpoint near the umlx) or at the apex. The apex terminates at or over-hangs a rudimentary pseudo area that slopes beneath the shell at anangle of la to 60 to the plane of the margins of the \alve. Thepseudo area is concave and about half the length of the space betweenthe apex and the plane of the valve. Casts of the interior show well-delined main vascular sinuses, with the outline of the visceral areabetween them.The dorsal \alve is transverse, nearly Hat in some examples, andslightly convex in others. The surface slopes gradually from themargins to near the umbo, where the slope increases and extends tothe upward-pointing apex. A rudimentary pseudo area slopes back-ward from the apex. In some examples the pseudo ai"ea appears to])e little more than a bending over of the posterior margins of the shell;in others it has the outline of a slightly convex pseudodeltidium.Olm-ri'afionH.?This species, in its reticidate surface ornamentation,recalls [plikhAla pwiiinda "and Mlckwltzia monilifevd. In form theyoung shells are not unlike Kutorgiva cingulata. A large, imperfectventral valve, 21 mm. by 21 mm., of this genus, was collected by Mr.
,]. E. Clayton from the Cambrian limestone of the Silver Peak dis-trict. It ma}" belong to K. 2>eragata^ and it is so referred for thepresent. From the shales of the Olenellus zone in Silver C^anyon,White Mountain range, a series of compressed specimens were col-lected. Some of these show a concave pseudo area on the ventralvalve, also strong main vascular sinuses. Some of the shells fromthe shales north of Red ^Mountain have lost all traces of surface char-acters, only a faint, smooth impression remaining.Formation and locality.?Lower Cambrian. Calcareous shalesbeneath Archceocyathus limestone, 8 miles north of Valcadi Spring or1 miles northwest of Drinkwater Mine; summit on road 10 milessouthwest of town of Silver Peak; also on divide between Claytonand Fish Creek valleys, north of Red Mountain, Silver Peak Range;Silver Peak District, Esmeralda County, Nevada. About 1,000 feetabov(^ quartzite, Silver Can3^on, White Mountain Range, Nevada.
NO. 1395. CAMBRIAN BRACBIOPODA? WALCOTT. 311KUTORGINA SARDINIAENSIS, new species.Kuiorgina cingulataBoMNEMANy:, Nova Acta der Ksl. Leop-Carol. DeutHch. Acad.Naturf., LVI, 1891, No. 3, p. 440, pi. xix, figs. 22, 23.Lhigula rouaulti Bornemann, Nova Acta der Ksl. Leop-Carol. Deutsch. Acad.Naturf., LVI, 1891, No. 3, p. 439, pi. xix, fig. 21.Transversely oval, more or less arched, with straight margin whichis a little shorter than the greatest breadth of the shell. Surface showsstrong concentric lines of growth.Found quite connnonly in the slates with OJenopsis and Metado.r-iileii near Canalgrande, solitary also in sandstone with Archmocyatltuson Punta Pintau. The specimens in slate are always pressed veryfiat, and are imperfect; in the sandstone are found impressions of theouter surface.Here belongs perhaps also the shell designated above as Linguhirouaulti (?).The specimens of this species are all more or less flattened in theargillaceous shale. It appears to be congeneric with Kutorcjhiu cin-guhita^ but not specifically identical with it.Formatwn and locality.?Middle? Cambrian shales near Canal-grande, and in sandstone on Punta Pintau, Island of Sardinia.KUTORGINA, species undetermined.Ventral valve transverse, moderately convex; length 6 mm., width8 mm. ; pseudo area short and sloping beneath the apex at an angle ofabout 45^.A single cast from a coarse sandstone is all that is known of thisspecies. It may be a young shell of K. cinguJata., but the means ofcomparison do not justify such a reference.Formation and locality.?Lower Cambrian sandstone of SoilingsMountain, 2 miles east of Natural Bridge, Virginia.RUSTELLA, new genusAll that is known of this genus is the type species, Rustella cdxoni.It appears to l)e the most primitive form of brachiopod known.The generic name is given in memory of William P. Kust, of Tren-ton Falls, New York, whose collections from the Lower Cambrianstrata of Georgia, Vermont, were most extensive and the material thefinest obtained there.RUSTELLA EDSONI, new species.General form, subcircular, biconvex. Ventral valve moderatel}'convex, with the apex at the posterior margin immediately al)ove alow arch in the posterior margin. Surface smooth except for concen-tric growth lines and low ridges that in some shells are quite prominent.A shallow, broad, rudimentary pedicle groove occurs beneath the apex
312 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvni.and on a slightly flattened space adjoining the posterior margin. Dor-sal valve a])out as convex as the ventral and with the apex marginal.The interior of the valve shows two rounded depressions beneath theumbo with a slight, narrow groove between them; a little in advancethe outlines of the central muscle scars occur; originally strong butfaintly indicated radiating lines occur toward the front.()])xerrat!(>n!<.?This shell was identihed as the dorsal valve of Kutor-(jlna ring 111(tt((. by Mr. Billings'^ and myself.* They were consideredas distorted, flattened shells. Better material shows them to representone of the simplest forms of brachiopod known; with the exception ofthe rudimentary pedicle furrow and the area there is nothing morethan the gaping valve, a form near to Dr. Charles PI Beecher's idealPatei'iiia.The specific name is given in recognition of the excellent work Mr.George Edson, of St. Albans, Vermont, is doing iu collecting theLower Paleozoic fossils of his region.Fonimtlon and locality.?Swanton shales, justabove Parker's quarry,Georgia, associated with Olenellus fhoaip.wnl,, and also two miles eastof Swanton, Vermont.Genus DICELLOMUS Hall.DiceUomus Hall, Twenty-third Ann. Rep. N. Y. State Cab. Nat. Hist., p. 246.Dicellomnx Hall and Clarke, Pal. New York, VHI, 1892, Pt. 1, p. 72.DiceUomus Walcott, Mon. U. S. Geol. Survey, XXXII, 1899, Pt. 2, p. 446.Shell small; general form ovate to subsemicircular, biconvex, withapices marginal. Surface of outer shell tinely punctate in all specieswhere it is preserved uninjured. Interior or middle lamellae markedby radiating striaj and minute punctee; inner surface finely punctate.The shell is thick in all the species now known, and is built up of athin, outer, scabrous layer, numerous inner layers or lamelke, and athin inner layer. Shell substance apparently calcareo-corneous.The interior of the ventral valve shows a short area with a medianpedicle groove; an elongate visceral area; well-marked main v^ascularsinuses; large, composite scars where the posterior muscles, i. e.,transmedian and anterior laterals, were attached; and a short shelf orembryo spondylium that extended into the valve from each side of thepedicle groove. This plate corresponds to the dental plate in thearticulate brachiopods, and it has a thickness at the antero-lateralmargin that suggests a short tooth.The interior of the dorsal valve has a well-defined but very narrowarea in one species, J), polltus.^ that is hollowed out so as to form ashallow groove on each side, apparently for the reception of the shorttooth of the ventral valve. No good posterior margins of the valveffPal. Fos., I, p. 9.^-Tenth Ann. Rept. U. S. Geol. Survey, p. 609, pi. lxix, figs. 1, la-h.
NO. 1395. CAMBRIAN BRACHIOPODA? WALCOTT. 313could be found of the other species of the genus. The composite scaris hirg-e, and in one shell it is subdivided into three small scars thatwere the points of attachment of the transmedian, outside, and middlelaterals. The central and anterior lateral scars are arranged as in(>hoh(s\ the centrals are large and located on the sides of the visceralarea; the anterior laterals are small and located at the arterial end ofthe visceral cavity.Oheervattons.?When referring to DiceUomus.^ in 1809, I said:"When proposing that the genus Dicellomus^ include OboleUa poliia, Professor Hallstated that the grooving or einargination of the apices of both valves and thethickening of the edges of the shell on each side below the apex, together with theform and character of the muscular impressions, would separate the species fromOboleUa. Again in 1892 Messrs. Hall and Clarke '' gave a fuller description ofDkelknnus politus, but owing to the poor character of the material they did not feelconfident that it should ])e recognized as generically distinct from OboleUa chromaiica.Material now in the collections of the Geological Survey clearly shows that ProfessorHall's provisional conclusion was correct, and that Dkellomus politus is genericallydistinct from OboleUa chroniatica.The ])resencc of the large, composite, cardinal muscle scars in eachvalve suggests that a search be made for a foramina! opening, as inOhohjllii, Lhindrsmudla., and Acrotreta. No trace has been foundexternally, and the interior of the ventral valve does not show evi-dence of it. D'lceUom uh appears to include characteristics of Oholusand OhoJelJa., and on the presence of the incipient dental plates, teeth,and dental grooves an articulate shell is suggested. In Meehina 'primaa step further is taken in the development of the spondylium and inthe approach toward articulating brachiopods.The stratigraphic range of DlceUoinns is from the Middle Cambrianto the latter part of the Upper Cambrian. Its geographic distribu-tion includes the Appalachian area in Tennessee and Alabama, theMississippi basin from Wisconsin and Minnesota on the north toOklahoma on the south and South Dokota, Montana, and Utah onthe west. The Arizona locality appears to be an extension to thesouthwest of the upper Mississippi Valley species, D. iJoUtus. Theonly form from Europe is suggested by the unidentified shell from theParadoxides forch.liainerl zone of Anduarum, Sweden.The species now referred to the genus are:Dicellomus appalaclila^ Middle Cambrian.D. jyarvus^ Middle Cambrian.I), jyectenoides, Middle Cambrian.D. politus^ Middle Cambrian.D. species undetermined. Middle Cambrian.D. nanu.^^ Upper Cambrian.
?Mon. U. S. Geol. Survey, XXXII, Pt. 2, 1899, p. 446.
''Twenty-third Ann. Kept. New York State Cab. Nat. Hist., p. 246.<'Pal. New York, VIII, Pt. 1, p. 72.
314 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.DICELLOMUS APPALACHIA, new species.Tliis .shell hiis heon identitied with I). poUtux in the preliminarystudies of the genus Dicellomus. I find that while it has the sametype of shell structure and g"eneral form, it differs in being less elon-gate proportionally, and in the details of the form and positions of themuscle scars and vascular markings of the interior of the valve; itdiffers in the latter respect from D. na)mi<. The outer thin layer hasa dull, slightly roughened surface that is minutely punctate. Whenthe outer layer is exfoliated the surface of the layer beneath is highlypolished and marked by exceedingly fine radiating strife and concen-tric stria* and lines of growth. The interior of the dorsal valve showsthe larger central muscle scars with the minute antero-lateral scarsalmost in contact with them. A composite scar shows the separatepoints of attachment of the transmedian, outside, and middle lateralscars. The variation in the length of the visceral cavity of the dorsalvalve is very great.This species occurs in great aljundancc in both limestones and shales.It is the representative of the widely distributed I). })olitu8 of theinterior of the continent. ' 'Foriii(it!(i/i and locality.?Middle Cambrian. Limestones beneaththe upper shale of the Cambrian section at many localities in Jeffersonand Hawkins counties; limestone layers in Conasauga shale, 2 milessouth of Coal Creek, Anderson County; in shale on road from Rogers-ville to Dodson Ford; limestone at Bull Run, Copper Ridge, 11 milesnorthwest of Knoxville, southwest of Maynardsville, and 5 milessoutheast of (xreenville. Tennessee.Coosa shale. CoAvan Creek and Cedar Bluff', Cherokee County, Mur-phees Valley, and Blountsville Valley, Alabama.DICELLOMUS NANUS Meek and Hayden.Oboh'/la nana jMeek and Hayden, Proc. Acad. Nat. Sci. Philadelphia, 2d ser.,V, 1861, p. 435.?Billings, Pal. Foss., I, 1862, p. 67.?Hayden, Am. Jour.Sci., 2d ser., XXXIII, 1863, p. 73.
?
Meek and Hayden, Pal. Upper Mis-souri, Pt. 1, 1864, p. 4, pi. I, figs. r>(i-d.?Whitfield, U. S. Geog. and Geol.Surv. Eocky Mountain Region, 1880, p. 340, pi. ii, figs. 14-17.?Hall andClarke, Pal. New York, VIII, 1892, Pt. 1, p. 69.Dicellomus nanus Walcott, Mon. U. S. Geol. Survey, XXXII, 1899, p. 447, pi.lx, figs 3, 3?-d.The principal characters of this species are the same as Dicellomuspolifm. The two forms diff'er exteriorly in D. nanus being more con-vex on the umbones and less elongate. The interior of the ventralvalve shows a less elongate visceral area, a relatively larger compositemuscle scar. The interior of the dorsal valve of D. nanus has a muchlarger composite muscle scar, a broader visceral area with the centralmuscle scar farther from the median line.
CAMBRIAN BRACHIOPODA? WALCOTT. 315One of the types of D. narniK is the interior of a ventral valve, onwhich there is a subtriangular depression that appears to have beenthe path of advance of the area, on each side of the median space, inAvhich the central muscle, middle, and outside lateral nuiscles wereattached. Another shell from the Big- Horn Mountains shows some-thing of the same character.The area of the ventral valve is short, and divided midway by ashallow pedicle furrow; area of dorsal valve unknown.The exterior of the shell appears to be smooth and slig-htl}' polished,except for tine concentric strite and lines of growth and what appearto be scattered puncta^.The average size of the adult shells is from 3 mm. to -l mm., thelength and width usually ])eing nearly the same.The exact horizon of the type specimens is unknown. The}' occurin a somewhat friable, purplish sandstone, unlike any beds of theMiddle Cambrian Deadwood sandstone that I met with. The speci-mens from the limestones of the Big Horn Mountains, etc., appearto belong to the Uppper Cambrian terrane.Fonnathm andlocality.?Upper Cambrian, Shal}' sandstone, BlackHills, North Dakota. Limestone above shales, about 10 miles south-southeast of Bald Mountain, Big Horn Mountains; Gallatin limestone.Crowfoot section, Gallatin Range, YelloM'stone National Park, W3^o-ming. Limestone of the Little Rocky Mountains, west side of DryvCreek, below Pass Creek, Gallatin Valley.Two specimens of a shell apparently identical with D. nanus werebroken from a diamond drill core, taken from a fine sandstone 20 feetabove the La Motte sandstone, St. Francois County, Missouri.\ DICELLOMUS PARVUS, new species.General form ovate, with the ventral valve subacuminate and dorsalvalve broad oval to sul)circular. Valves moderately convex. Surfaceof outer shell dai'k and polished; it is marked, when not abi'aded, bytine, clearly defined, concentric strite and occasional lines of growth.The largest ventral valve has a length of 2.5 nun. and a width of2 mm. The shell is strong but not thick. Shell substance apparentlycalcareo-corneouft.Ventral valve uniform!}' convex, except that the slopes toward thecardinal margins are more abrupt than elsewhere; apex appears to bemarginal. The interior of the valve shows a short, low, median ridgein the center of the visceral cavity; on each side, and a little in frontof the end of the median ridge are the trapezoidal areas for the attach-ment of muscle scars; rather small, composite cardinal muscle scarsoccur close to the cardinal margins.Dorsal valve somewhat less convex than the ventral; apex marginal.The interior of the valve shows well defined composite cardinal muscle
81() I'llOVEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
scars, a narrow nu>diau septum, and faintly impressed main vascularsinus that curves outward and forward at al)out one-third the distancefrom the out(n- margin to the median septum; the central nuiscle scarsare small and situated l)ack of the center of the valve on each side of alow median swelling on which the median septum oocurs; the positionof the anterior lateral umscle scars is indicated at the end of the medianseptum a little in advance of the center of the valve.OIm;rvatl<ms.?This minute shell has the generic characters of D!cel-loriixs pol/txK, but it differs specifically in minute size and the positionsof the muscle scars in the dorsal valve.Formation and locality.?Middle Caml)rian. Chang Hsia limestone.Two and oiu>-half miles southwest of Yen Chuang, Shantung, China.Also from a river di'ift block one mile south of Chen Ping Hsien, onthe Lan llo liiver, southern Shensi.Collections of Bailey Willis and Eliot T. Blackwelder, CarnegieInstitution Expedition to China.DICELLOMUS PECTENOIDES Whitfield.
OholiiH iHcUiioidcx WiiiTiaELi), Ludlow's Kept. KeconnaiHSixiice Black Hills ofDakota, 1.S75, p. 103, figs. 1, 3.Ohulus? pecteiioUh's Whitfield, Geo!, aiul (Tei),g. Surv. Kocky IMountain region,Powell, 1880, p. 328, pi. ii, figs. 18, 19.Oholelld. ])frtrii(>t(li'ff Schuchert, Bull. U. S. Geol. Survey, No. 87, 1897, p. 275.This is the largest shell of the several species of the genus. Aventral valve 1> nmi. long has a width of 11 nun. All that is known ofthe structure of the shell indicates that it was like D. politiis. Thisspecies differs from all the other species by the anterior iDosition ofthe central nmscle scars of the dorsal valve, and its larger size.Foriiaitloii and Joixdity.?Middle Cambi'ian. Deadwood sandstone,Castle County, on west side of the Black Hills; also at Deadwood, inthe cliffs on the east side of the valley. South Dakota.DICELLOMUS POLITUS Hall.Oholus appolinm Owen (not Eichwald), Geol. Surv. Wisconsin, Iowa, andMinnesota, 1852, ]il. i u, figs. 9, 11, 15, 20.Lingula ! jyolita Hall, Ann. Kept. Geol. Surv. Wisconsin, 1861, p. 24; Geol.Kept, Wisconsin, I, 1862, pp. 21, 435.OlxiJrIld ? polUa Hall, Sixteenth Ann. Kept. New York State Cab. Nat. Hist.,1863, p. 133, pi. VI, figs. 17-21; Trans. Albany Institute, V, 1867, p. 112.Liugalepii^ prrima Meek and Havden, Smithsonian Contrb. to Knowl., XIV,1864, No. 172, p. 3, pi. i, fig. 2.Diccllorims j'olila Hall, Twenty-third Ann. Kept. New York State Cab. Nat.Hist., 1873, p. 246.Oholdla politit Whitfield, Geol. and Geog. Surv. Kocky Mountain Region, 1880,p. 339, jil. II, figs. 12, 13.OboJdla poUla Walcott, Bull. U. S. Geol. Survey No. 30, 1886, p. 111.
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 317OboleUa pulita Hall and Clarke, Pal. New York, VIII, 1893, Pt. 1, pp. 72, 73,pi. II, fig?. 37-41.DiceUomus polUns Walcott, Mon. U. 8. Geol. Survey, XXXII, 1899, Pt. 2,p. 446, pi. L.>;, figs. 4, 4a.General form ovate, with the ventral valve subacuniinate; biconvex,the ventral valve usuallly more convex than the dorsal. Surfacesmooth as the specimens usually occur, but a few examples show thatthere is a thin outer layer covered with fine papilte and punctge thatappear to be placed on very tine, more or less inosculating ridges.Concentric lines of growth of varying strength show on the outer sur-face, also on the various inner layers or lamella?. When the outerlayer is exfoliated or worn off by attrition of the sand, the surface ofthe inner layer is marked by radiating strite and concentric lines ofgrowth that are a marked feature of the species. The radiating striaemay be uniform in size, or with from 4 to 6 very fine striae betweentwo stronger elevated stria?. Inner surface smooth to the eye, but astrong lens shows that it is finely punctate, with exceedingly fine,irregular, raised lines all over the surface. The intermediate layeris more coarsely and irregularl}^ punctate.The shell is thick and is built up of a thin, scabrous, outer layer, amiddle kwer made up of several highly polished lamellfe, and a thininner layer. The numerous inner lamellae are oblique to the outersui-face over much of the shell, and thus give it thickness. Shellsubstance calcareo-corneous. The usual size of the Wisconsin shellsis about 6 mm. long, width 5 mm., for ventral valve, and same widthand length for dorsal valve. Specimens from the Black Hills averagea trifle larger than those from Wisconsin.Ventral valve with a uniform convexity over the central portions,from which the surface slopes gently to the margins. Apex nearly,if not quite, marginal. Casts of the interior indicate a short cardinalarea that extends out on the cardinal margins of the shell, and thatappears to merge into the margins. On each side of the pedicle fur-row a thin plate or shelf extended into the vah^e on the plane of themargins of the shell. Some of the casts indicate that these plates hada projecting boss or tooth that articulated in a rude manner with thedepressions on the posterior, flattened, inner margin of the dorsalvalve. If this interpretation is correct, the teeth and plates corre-spond to the teeth and dental plates of the articulate brachiopods, andthe plates mark the beginning of a spondylium. The posterior mus-cles, transmedian and anterior laterals were undoulUedly attachedwithin the area of the composite scar. The visceral area and poste-rior portions of the main vascular sinuses are well outlined, but nonmscle scars or details of the vascular S3^stem have been preserved inthe material studied.Dorsal valve most convex back of the center. Apex marginal. TheProc. N. M. vol. xxviii?04 21
318 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvm.interior of the valve shows shallow depressions in the flattened pos-terior margin that sug'gest dental cavities for the reception of the den-tal projections of the ventral valve. The composite muscle scar prob-ably formed the point of attachment of the posterior muscles, trans-median, outside, and middle laterals. The central muscle scars areshown a little back of the center of the valve, where a low medianridge bifurcates. In some shells a sharp median septum is shown; alsonarrow main vascular sinuses.Ohscrvations.?The specimens of this shell from Wisconsin, Minne-sota, and North Dakota occur in fine-grained, more or less friablesandstone; those from Montana in a compact limestone in the GallatinValley and a siliceous shale at Helena. The reference of the speci-mens from Helena is rather doubtful, as the shells are compressed anddistorted.The ])eds in which the specimens are found at Taylors Falls, Minne-sota, are said to be Upper Cambrian. If this is correct D. politusranges from the Middle to the Upper Cambrian. Shells agreeing withD. j)<dit/(.'< in all points available for comparison occur in the basal,probably Middle Cambrian, sandstone beneath the great limestoneseries of Arizona. The material is abundant and preserved very muchin the same condition as that from the Deadwood sandstone of theBlack Hills of South Dakota.In the sandstones at the base of the Middle Caml>rian Reagan forma-tion a few shells were found that appear to be identical with D. politus.They have the elongate form of that species, which is unknown in anyother species of the genus.In the collections made b}' the fortieth parallel survey there arespecimens so closel}^ resembling I). polltuH that they are identified assuch, although the dorsal valve is rather transverse.DlcelJohnis 2>ol/ti(!< differs from Ij. nanns and D. pectenoldes in beingmore elongate; also in the details of the interior markings of the valves.From D. appahiclihi it differs in interior markings and, as specimensaverage, in ])eing more elongate.ForiHdt'ion und locality.?Middle Cambrian. St. Croix sandstone,middle ))eds of the sandstone, at Eau Claire, Wisconsin. Deadwoodsandstone, 9 miles west of Custer City; head of Red Water Canyonand several other localities in the Deadwood standstone of the BlackHills, South Dakota. (lallatin limestone, near Gallatin, and also inSilurian shales with (Jholns {Lingulell(() helena and 0. ( Westo'ria) ella.,on the southern slope of Mount Helena at Helena, Montana. Basalsandstone. Ash Creek, Pinal Count}^ Arizona. Basal sandstone of theReagan formation, Wichita Mountains, 11 miles northwest of FortSill in the SW. i sec. 17, T. -t N., R. 12 W., Oklahoma Territory.Upper {'.) Candjrian. Up|)er beds of St. Croix sandstone at TaylorsFalls, Minnesota.
NO. 1395. CAMBRIAN BRACEIOPODA?WALCOTT. 319DICELLOMUS, species undetermined.A single specimen of a ^?^MltnlI valve verv nuich like that of 7>i<rl-loinu.s appalaclud occurs with material from the J\ir<i<J<),i'lde>< forcli-iHUiwri zone at Andrarum. A series of specimens would probablyprove that it is the representative of an undescribed species.Formati07h and locality.?Middle Cambrian. Andrarum, Sweden.CURTICIA, new genus.The description of the type species, Cnrtlcla elegatdvla, includes allthat is known of this genus.The generic name is given in recognition of the excellent work ofDr. Cooper Curtice, of Moravia, New York, ])oth as a field collectorand laboratory assistant for se^'eral years.CURTICIA ELEGANTULA, new species.General form, subcircular, biconvex. Surface of exterior of shellmarked by fine concentric, slightly undulating stritB, and lines andvarices of grow^th. When the thin, exterior layer is exfoliated, theinner lavers are ornamented bj' numerous tine, radiating lines, verymuch as in Dicellomus and Obolus, also more or less imbricating con-centric lines. The inner surface shows radiating and concentric lineswithout the visceral area. Shell substance corneous and probabl}^ cal-careous. The shell is built up of a thin, outer surface layer and sev-eral inner layers or lamella?, slighth' oblique to the outer surface onthe laiibo and central parts of the valves. The lamella are moreoblique and numerous toward the front and sides, and thus thicken theshell over those parts. The average ventral valve has a length of5 mm., width 6 mm.; dorsal valve, 5 mm. by 5 nmi.Ventral valve strongly convex, most elevated at the umbo, andarching over to a minute, slighth" incurved apex; area rudimentary,with a high, triangular, open delthyrium occupying most of it. Acast of the interior of the valve shows that a narrow elevated ridgeoccurs just in advance of the apex.Dorsal valve evenly convex, apex marginal. The interior shows amedian ridge and septum, with small rounded depressions beneath theumbo on each side of the median ridge and a little in advance of theapex. Ventral nmscle scars small and clearl}^ defined. Anterior lat-eral scars small, and situated in advance of the central scars close tothe median ridge and at its anterior extremity. Main vascular sinusesbroad and slightly defined.Ohsenmtions.?This shell was \ahe\ed Dlcello))ms 2)oUtus. In exter-nal form it resembles it, but the open delthyrium of the ventral valveand the absence of area on dorsal valve distinguish it. It appearsto be a form intermediate in development between Mustella and Dicel-
320 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
loiiiths. It occurs in laro'o nunil)er.s and i,s a very striking- object, withits dark, smooth shell in the burt'-o'ray sandstone.Forniafioii and Ayrr///Vy. ?Upper Cambrian. St. Croix sandstone,Taylors Falls, Minnesota.QUEBECIA, ne^w genus.The description of the species inchides that of the genus as there isonly one species now known.Type.? Oholdla dree Bi 1 1 i ng-s.QUEBECIA CIRCE Billings.
()},<ilill(i circc P>ii,T>ix(;s, Canadian Xat., ii. f^er., VI, 1872, p. 219; Am. Jour.Sci., .'id Her., Ill, 1<S72, p. ;!57.
?
AValcott, Bull. V. S. (ieol. Survey No.30, IKSH, p. lis, pi. x, iig. .Sa; Tenth Ann. Rej)!. IT. S. Geol. Survey, 1891,p. (il 1, ])1. i.x.xi, iig. 8a.General form broad ovate, with fi'ont and sides uniforndy rounded;planoconvex. Surface marked l)y tine concentric strii\? of growth.A ventral valve 8.5 umi. in length has a width of 4.5 mm. A dorsalvalve 4.5 mm. in length has the same width; a larger dorsal valve,11 lum. in length, has a width of 10.5 mm. Shell rather thick, andcomposed of calcite in its present condition.The ventral valve has an elevated umbo terminating in a sharp,upward pointing apex that may be perforate; from the umbo the sur-face, in young shells, slopes so rapidly that the central and outer por-tions of the shell are nearly Hat, l)ut in older shells moderately convex;area short and divided midway l)y a relatively broad delthyrium thatis nearly covered by a convex deltidium; the inner surface is markedby tine, elevated, rather widely separated, radiating strite and veryhue puncta^; a pair of very broad main vascular sinuses arch forwardfrom a point beneath the umbo and inclose a small, slightly elevatedvisceral area; a strong cardinal tul)ercle occurs on each side of thepseudo area, which was probably the point of attachment of theposterior muscle, i. e., transmedian and anterior laterals.Dorsal valve gently convex in young shells, l)ecoming strongly con-vex in old shells; no traces of an area have been ol)served?if presentit nmst have been short and very low, as the beak is nearly at theplane of the margins of the shell; casts of the interior show that thevalve was thickened beneath the umbo by a ridge that separated whatmay be called the umbonal cavity from the main cavity of the valve.On the cast of an old shell a rounded, narrow, longitudinal, medianridge divides the innl)onal cavity; on each side of the cavity and beyondit there is the strongly marked path of advance of the transmediannniscle scars; in front of the transverse ridge two strong ridges thatextend toward the center of the valve occupy the position of the mainvascidar trurdvs; in one specimen a narrow groove extends from thecentral nuiscle scar along the inside margin of the ridge.
NO. 1395. CA MBRI. 1 .Y BRA CHTOPOBA?WALCO TT. 821The muscle scars now known are the transniedian and central; theformer are situated close to the marg-in of the valve, and the s})aceassig-iied them may also include the posterior laterals; the central scarsare well indicated in several specimens, but no trace has been found ofthe antero-laterals. The cardinal tubercle includes the spuce that wasoccupied b_y the several points of attachment of the posterior muscles,i. e., transmedian, outside, and middle laterals; the east of the tubercleis an elong-ate depression just inside the maroin of the shell.Ohservatloiix.?By incorrect interpretation both Mr. Billings andmyself identified the dorsal valve of the species as the ventral, and Ifollowed him in illustrating a dorsal valve of Oholellacrami as the dor-sal valve of (J. Circe. When studying some material representing thespecies in the collections of the United States National Museum Inoticed the edge of a shell that, on working it free from the matrix,proved to be a ventral valve; two dorsal valves occur on the same ])itof rock. Subsequently Dr. .1. F. Whiteavessent me a tablet from thecollections of tlio (xeolog-ical Surve}^ of Canada, on which six specimenswere labeled OholeUa dree. No, 1 is a cast of the interior of the dor-sal valve of OholeUa crasi^a^ and No. 2 the exterior of same. Nos. 3 and6 are ventral valves of Qiieheda circe, and Nos. 4 and 5 dorsal valves.With the ventral valve identitied, it appears that the shell is not anOholeUa but is the type of an undescribed genus, in which the ventralvalve is elevated at the apex, and with strong cardinal tubercles for theattachment of the posterior nmscle scars, very nmch as in Acrotreta.This feature, and the presence of what appears to be the base of thecast of a foraminal tube, suggest that the ventral valve was perforate.Quehecia appears to be on the line of evolution from Oholdla to thecalcareous, perforate, inarticulate shells represented by Yorh'ia.OholeUa, Qiieheda, and Yorl'/a are all strong, calcareous, perforateshells of the older Cambrian fauna, and are evidently closely related.Formation aiiel locality.?Lower Cambrian. Limestone bowlders inconglomerate at Trois Pistoles, on the St. Lawrence River, belowQuebec, Canada. Genus ELKANIA Ford.BUlimjsia Ford (not de Koninck, 1876), Aiiier. Jour. Sci., 8d ser., XXXI, 1886,p. 466.Elkania Ford, Amer. Jour. Sci., 3d ser., XXXII, 1886, p. 325.Elkania Hall and Clarke, Pal. New York, VIII, 1892, Pt. 1, pp. 75, 165;Eleventh Ann. Rep. New York State Geologist, 1894, p. 241.General form ovate, biconvex; shell substance corneous and madeup of several thin layers or lamelhe that increase in number towardthe front and lateral margins. Surface marked by line concentricstria? of growth. Apex of both ventral and dorsal valves marginal.The interior of the ventral valve has a thickened posterior section whichhas a central pedicle furrow, and two tiexure lines running obliquely
3 2 '2 PROCEEDlNas OF THE NATIONAL MUSEUM. voi. xxvni.forward and outward from the apex, a little inside of the grooves ofthe main vascular ti'unks; this structure is apparently the result of theunion of the area with the bottom of the shell, so as to bring, as theshell grew, the path of advance of the pedicle groove, main vascularsinuses, and lateral muscle scars all on one surface instead of on thearea and the shell beneath it, as in OJxthis.The muscle scars are arranged as in (Jhohts. The transmedian andanterior laterals occur well out toward the margin, and the spaceinclosing the central scars, middle and outside laterals, is in the centralarea, on the front of the slope of the thickened posterior portion ofthe valve; the points of attachment of the individual muscles can notbe distinguished. In the doi'sal valve the central and anterior lateralscars are clearly shown in several specimens. The transmedian andoutside laterals are situated just outside the main vascular sinus. Ourknowledge of the vascular markings is limited to the main vascularsinuses, except in one ventral A^alve where the inner branches have beenpreserved. In l)oth valves the main trunk rises near the apex and itspath is outlined across the reversed area.The preceding description differs materially from that of Messrs.Ford and Hall and Clarke. I tind the muscle scars as described above,and am compelled to consider them as indicating the same muscles asin Ohol )is. That the genus is an advance on Oholus in the evolutionof the inarticulate brachiopods, I quite agree with Hall and Clarke;also that it is a stage in the transition from OhoJus to TrlriiereUa andits allies. The stage, however, is not far along, as nothing is seen ofthe platform in advance of the area, and the area is merged into thebody of the shell. Ell'iohla is an (>h<)lu><\\\\\\ the cardinal areas withinthe plane of the margins of the valves. In the type species, ^i^. desid-eratd^ the area of the ventral valve is entirely within the valve, whilethat of the dorsal valve has been nearly obliterated in the process ofchange from an open backward-facing area to an inclosed forward-facing area. A compaiison of the interiors of Oholus {L.) codatusand (Jholvs apolUnis with those of ElJainla desiderata and Elhanta,hdhda illustrates that little change is necessar}^ to convert the exteriorcardinal areas of Oholus into the inclosed reversed areas of Elkania.As the beaks of EJkania are marginal, the pedicle passed outthough an opening made by the gaping of the valves.The four kiiown species of the genus are the tvpe species, EJkanladesiderata^ E. ida, E. amhix/ua, in which the shell is very thick, andE. helhdu, a minute shell in which the form and tendency is towardsLhigidelJa rather than the thick oval forms of Oholus.hingidasina Ulrich, has an inclosed cardinal area, and is a moreadvanced stage than Elkania in the transition from Oholus ?indi its sub-genera to the true Trimerelloid forms."
?See Pill. New York, VI II, I't. \,\^\^. 24-28, .'W-SS.
NO. 1395. CAMBRIAN BRACHIOPODA? WALCOTT. 323Authors have referred frequently to the resemblances betweenspeeies of Obolella and Elh((i}ia desiderata. These do not appear toexist except in a superficial manner. Obolella is a stage in the evolu-tion toward the Siphono-tretidte, while Elkania is toward the Tri-merellida'. ELKANIA BELLULA, new species.General form elongate oval; biconvex; beaks marginal. Surfacemarked by line concentric stritv of growth that occasionally formvaracies and small ridges near the umbo; the inner layers or lamallfehave radiating striae in addition to concentric stri^.The shell is relatively thin and small. It rarely exceeds 2.5 mm.in length and a little less in width; the dorsal valve is a somewhatshorter than the ventral.Ventral valve subacuminate, moderately convex; the interior showsa reversed cardinal area attached to the bottom of the valv^e and belowthe plane of the margins of the valve; the pedicle groove is strong;the line of demarcation between the cardinal area and the bottom ofthe valve is indefinite, as the margin of the area and the body of theshell have been merged into each other; the transmedian and antero-lateral muscle scars are outside the main vascular sinuses and nearthe margin of the valve; the central scars and middle and outsidelateral scars are supposed to have been attached within an area whichis largely on the front slope of the thickening of the umbonal portionof the valve.The dorsal valve has a short reversed area; the antero-lateral musclescars were probably well advanced toward the front, judging fromtraces of the length of the visceral cavity.The vascular markings include the main vascular sinuses in the ven-tral valve and traces of the \ isceral area in the dorsal valve.This pretty little shell is much like a small species of Lingtdella inits exterior appearance; the interior connects it with Elkania. I knowof no species closely related to it.Eorniation and locality.?Upper Cambrian. Limestone about 3miles south of Benders Pass, Silver Peak Range, Nevada.SCHUCHERTINA, new genus.The description of the type species is that of the genus and species,as but one species is known of the genus.Type.?ScliucheTtina camhria.The generic name is given in recognition of the admirable work thatProf. Charles Schuchert has done on the fossil brachiopods.SCHUCHERTINA CAMBRIA, new species.Shell subovate, with valves obtusely acuminate; biconvex. Sur-face marked by concentric lines and striae of growth and fine radiating
324 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
.striiK. The inner and outer .surfuces of theshells have very line punctse,but no traces of punctte penetrating- throug-h the shell have beenobserved.The largest venti'al valve has a lengtli of 22 mm., width 23 mm.;dorsal valve, length 17 mm., width 18 mm. Shell substance calcare-ous, rather thick on the umbonal region and thin towards the margins.Ventral valve subacuminate, moderatel}^ convex; on some of thelarger shells a broad mesial fold and arching of the frontal margin arepresent; apex terminates at the margin above a triangular opening ordelthyrium; area small and within the plane of the margins of thevalve; it is attached to the bottom of the valve and divided midway bya very slight pedicle groove; the margins of the delthyrium-like open-ing sustain an angle of about 45" to the plane of the valve, and thereversed area within is at its center nearly on the plane of the valve;the anterior margins of the area extend upward to meet the marginsof the shell, thus forming a reversed arched area. The interior of thevalve is marked l)y radiating, shallow, narrow furrows that vary innumber and strength in different shells; just in front of the area oneach side of the median line oval depressions occiu* which correspondin position and shape to the diductor muscle scars of the ventral valveof the Orthidffi, and they are so interpreted. Traces of the adductorscars are found on each side of the median line. Dorsal valve obtuselyacuminate, about as convex as the ventral valve; apex marginal onthe broad, low, median arch of the posterior margin; no traces of anarea have been observed. A broad, shallow mesial sinus and project-ing front margin occur on adult shells. The position of the anteriorand posterior adductor muscle scars is indicated, also the umbonalthickening in which the diductor muscles were probably attached, asthere is no trace of a cardinal process. Radiating furrows like thosein the ventral valve are strongly marked in adult shells.(>})Hei'vatUni!<,? ^eliuclievtina camhria is a shell that, as far as 1 know,is unique. In its exterior form it suggests a biconvex Orthoid genus,and this likeness is further increased by the ilabelliform scars of theventral valve; the smooth surface and reversed areas suggest Ellaivla.,while the interior imibonal portion of the ventral valve points toQaehecia. It may be said that Schuchertina is a type derived fromsome eai'ly Cambrian form allied to Quebecia and that its generalaspects affiliate it with the Orthida^.Formation, and locaJ/ity.?Middle Cambrian limestone. Thirteenmiles south of Neihart, 1 mile below divide on road to Woolsey post-office, Montana. OBOLUS ACADICA, new species.Only interiors of the dorsal valve of this species occur in the col-lections made by Mr. S. W. Loper on McNeils Brook in 1900. The
CAMBRIAN BRACHIOPODA?WALCOTT. 325
material was provisionally referred to 0. (Z) c(?i<-!ji/)hs^ l)ut thel)roa(llv rounded subquadrilateral form of the dorsal valve seems todistinguish it from that species and also from Oholns {Paleoho'x.s)hrefonmsis.The visceral area is narrow, extending a little in advance of thecenter of the valve. The main vascular trunks are narrow and widelyseparated. They belong to the submarginal group and are thus quiteunlike those of O. (7^,) hreioncnslx. The exterior surface and ventralvalve are unknown.Formnt'ton and londlty.?Upper Cambrian. Etage 3 of Matthew,McNeils Brook, 1^ miles east of Marion Bridge. Cape Breton, NovaScotia. OBOLUS ISMENE. new species.This species is characterized l)y its elevated umbo, flattened posterio-lateral margins, and relatively thin shell.All that is known of the exterior surface indicates that it was nearlysmooth, marked only by tine concentric striae of growth. The innerlayers of the shell are beautifully marked by tine concentric and radi-ating strife that give the surface a cancellated appearance. The shellis built up of several layers or lamellse that become more oblique tothe outer surface toward the front.Formation and locality.?Middle Cambrian. Fotosi limestone, FlatRiver, Missouri. OBOLUS MATINALIS Hall?Lingulepis matinalis Hall, Sixteenth Annual Report N. Y. State Cab. Nat. Hist.,1863, p. 130, pi. VI, figs. 12, 13.A form indistinguishable from this species occurs in a gray lime-stone of Upper Cambrian age. Only the general form of partiallyexfoliated shells is known.FoTmation and locality.?Upper Cambrian. Chao Mi Tien lime-stone. Two-thirds of a mile west of Tai An Fu, Shantung, China.Collection of Eliot T. Blackwelder, Carnegie Institution Expeditionto China. OBOLUS MINIMUS, new species.This is a small shell of the general form of Ohohts shenslensls. Theventral valve is obtusely accuminate and the dorsal nearly circular;valves gently convex. Surface marked by rather strong concentriclines of growth and numerous very line concentric stria?. The innerlayers of shell are shiny black and ornamented with numerous tine,radiating striae and concentric lines. Shell built up of several thinlayers or lamellae that form a thin shell over the lambonal region thatgradually' thickens as the short, oblique lamella? become more numer-ous toward the front and side margins. The three specimens in the
320 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.
collection average 3 nnn. in transverse diameter; the ventral is a littlelonger than the dorsal valve.A partiall}" exfoliated ventral valve shows a well-marked visceralarea, extending forward about one-third of the length of the shell;also narrow main vascular sinuses starting near the apex and extend-ing obli(piely forward well into the valve, about midway between themedian line of the valve and the lateral margins. This neat little shellis distinguislu^d by its nearly circular outline, low convexity, andsmall size.Formation (iiid localtty.?Middle Caml)rian. Chang Hsia limestone,Yen Chuang, Shantung, China.Collection of Eliot T. Blackwelder, Carnegie Institution Expeditionto China. OBOLUS NUNDINA, new species.This little shell difi'ers from (J. anceps^ to which it appears to bemost nearl}^ related, by its more nearly circular dorsal valve, and itsstrongly concentrically-ridged surface. Its surface is formed by ele-vated, rounded, concentric ridges that are somewhat irregular. Veryfine concentric striiB occur ])oth on the ridges and on the interspacesbetween.FoniKition and locality.?Middle Cambrian. (>old Creek, LlanoCounty, Texas. OBOLUS OBSCURUS, new species.This species is represented by one interior of a small dorsal valvewliich is very distinctive, the exterior of a crushed dorsal valve, andnumerous fragments of the shell scattered through the hard, darkgray, shaly sandstone. The large dorsal valve has a length of 9 nnn.,width T nnn. The shell is strong and marked on its inner la^^ers byradiating and concentric striae; the outer surface has numerous tine,elevated, slightly irregular concentric stride that, with a strong lens,give it a roughened appearance.An interior of a dorsal valve shows a well-developed area, thegreater portion of which is taken b}" the broad pedicle groove; a deepumbonal cavity with a narrow median septum and obscure main vas-cular sinuses on the outer margins of the oavit3^ Outside the sinuseson the postero-lateral slope, relatively large muscle scars are indicated.With the data available no satisfactory comparisons can be madewith other species. O. ohscurus is a large strong shell of the generaltype of Oholns rhca of the Middle Cambrian of Wisconsin.Formation, and locality.?Middle CJambrian. Ku San shale. Threeand one-half miles southwest of Yen Chuang, Shantung, China.Collection of Eliot T. Blackwelder, Carnegie Institution Expedition.
N0.1395. CAMBRIAN BRACHIOPODA?WALCOTT. 327OBOLUS SHENSIENSIS, new species.General form ovate, with the ventral valve Ijroadh' subacuniiiiateand dorsal valve obtusely rounded. Valves moderately convex in thespecimens embedded in a fine-grained, dark limestone. Surface markedl)y fine, sharp, concentric strias and traces of irregular, obscurelydefined, low, radiating ridges; the interior layers show tine radiatingstrife and concentric lines. The shell is strong and built up of numer-ous lamelke o])lique to the outer surface. The largest ventral valvehas a length of U mm., width 7 nun. Nothing is known of the interiorof the valves. The form, surface markings, and shell structure aremuch like those of Oholus inatinalm and O. tetonen,ns. In outline(>. shensiensis is more elongate than O. nudhutUx and less so than(K tetonensis.Formation und locality.?Upper Cam])rian. Chao Mi Tien lime-stone. Eight miles south of Ting Hsiang Hsien, and one mile southof Chen Ping Hsien, Shensi, China.Collections of Bailey Willis and Elliot T. Blackwelder, CarnegieInstitution Expedition to China.OBOLUS TETONENSIS, new species.The general form, convexity, and appearance of this species is somuch like that of Oholu/^ matlnalis that a general description isunnecessary. It varies from that species in the shorter, more trans-verse dorsal valve, and the narrower outline of the ventral valvetoward the beak.This species occurs in great abundance in the thin-l)edded limestonein the upper portion of the Cambrian section of the Teton Range,Wyoming, in association with B'dlliKjHdla pep'tna and Oholu-s {Liiuju-lepdn) acuminat'UH var. meekl. What appears to be the same speciesoccurs nearl}^ 700 feet lower in the section in a thin-bedded sandstone.The dorsal valve from this horizon is broader and more transverseposteriorly than the dorsal valve from the upper horizon.Formation and locality.?Middle Camln-ian, on the divide at thehead of Sheep Creek, near north end of the Teton Range, Wyoming.Thin-bedded limestones. Belt Park, 6 miles out from Neihart, Mon-tana. Three miles southeast of Malad City, Idaho, a smaller form,collected by Dr. A. C. Peale in Bostwick Canyon, Bridge r Range,Montana, ma}^ belong to this species. It occurs in a fine-grainedsandstone low down in the Paleozoic section.Dark gray limestone, Ophir City, Utah.
828 PROfEEDTXas OF THE NATTOXAL MFSEUM. vol. xxviii.OBOLUS TETONENSIS NINUS, new variety.This variet}^ differs t'l'om the })ar(nit species and from (/. inathialisby the more elongate form of the dorsal valve and the more acuminateform of the ventral valve, the cardinal slopes of the latter extendingmuch further forward in the variety ninas than in the two species.The advanced ]K)sition of tlie visceral area in the ventral valve mayhe compai'ed with the visceral area of Ohohis (L.) crax^ux.Fornuitlon <iud locality.?Middle Cam])rian. Reagan formation,one-half mile east of Canyon Creek, 15 miles northwest of Fort Sill,Oklahoma Territor}-; also on west side of Honey Creek, near SE.corner, sec. 86, T. 1 S., R. 1 E. NE. i sec. 2, T. 2 S., R. 1 E. Ard-more map, (ireological Survey, Indian Territory.OBOLUS PHERES, new species.Tliis is one of the smallest of the Oholus species known to me. Itrecalls at first sight 0. (Z.) 'wino/ta conve.tus,' but it dilfers in havinga thick, lamellated shell, and in being more rounded on the cardinalangles. The exterior surface is marked by concentric lines of growth.The shell is built up of thin layers or lamelhe, those toward the frontand sides being arranged obliquely to the surface, as in all of thethick-shelled species of Ohohix.Forniatloh and locality.?Uppei- Cambrian. Argillaceous shales,interbedded in sandstone at Fox Glen, 8 miles east of Baraboo,Wisconsin.OBOLUS (LINGULELLA) CHINENSIS, new species.General form ])roadly subovate with the ventral valve broadly sub-acuminate and the dorsal valve oval with the postero-lateral slopessomewhat straightened. There is some variation in the proportionsof width and length in different shells. Valves rather strongly convexfor so thin a shell, in this respect resembling species of Dicellohius.Surface marked by tine concentric stri^ and lines of growth and veryfine undulating concentric lines; this outer surface is usually a dullblack and adheres to the matrix; when the outer layer is exfoliatedthe surface is shin}'^ black and marked by numerous radiating striss inaddition to concentric strite; the inner surface shows a few scatteredpunctte in addition to radiating and concentric stri{? outside the vis-ceral area. The shell is of medium thickness and formed of a thinouter layer and several inner layers or lamellae that are slightly obliqueto the outer la3^er; the lamella? are more numerous and more obliqueto the outer layer over the anterior and antero-lateral portions of theshell. The ventral valves average 3 mm. in length, with width vary-ing from 2 nmi. to 2.6 mm. The dorsal valve is slightly shorter thanthe ventral when the two valves have the same width.
NO. 1395. CAMBRIAN BRACHIOPODA? WALCOTT. 329The interior of the ventral valve shows that the area is short anddivided midway by a narrow pedicle furrow that merges into the vis-ceral area, which extends forward about one-third the length of thevalve; on each side of the anterior central portion of the visceral areathere are two small trapezoidal areas within which the central scars andthe middle and outside lateral muscle scars were attached ; the small trans-median and antero-lateral muscle scars are situated close to the mainvascular sinus opposite the anterior portion of the central visceralarea. A partial cast of the interior of the dorsal valve shows a ratherwide visceral area with the antero-lateral scars about the center ofthe valve and the central scars about one-fourth of the distance backfrom the center to the posterior margin. Of the impressions left bythe vascular system only the main vascular sinuses of the ventral valvehave been seen; these are situated about midway between the centralvisceral area and the margins of the valve.Observations.?This species occurs abundantly in association withAcrotreta shantu/Kjensis. It is closely related in form to O. {Lmgii-lella) prlndell of the upper Olcnellus zone of eastern New York, andbelongs with a group of small shells that have a wide vertical andgeographical range, as is noted under the description of (>. L. prindeli.With the data availal)le for comparison it differs from O. L. prmdcUin its shorter cardinal area and visceral area in the dorsal valve.From 0. {L'mgaleUa) daniesi it differs in being broader in proportionto its length.Formation and locality.?Middle Cambrian. Chang llsia limestone.Two and one-half miles south of Yen Chuang, on NNE. spur of HuLu Shan, China.Collected by Mr. Eliot T. Blackwelder, of the Carnegie InstitutionExpedition to China.
' OBOLUS (LINGULELLA) DAMESI, new species.The general descriptions of O. L. ehinensis and <). L. pri/zn/s applyso closely to this species that it does not appear necessary to do morethan call attention to the points in which they differ. From 0. L.ehinensis this species varies in having a more elongate, acuminateventral valve and ovate dorsal valve; the valves are also less convex.From 0. L. primus it differs in the more gradual curvature of thesides from the apex to the front margin, in this respect resemblingsome varieties of O. L. ferrmjineous. The average size of the ventralvalve is about 5 mm. in length by 3.5 mm. in width.The species is named after Dr. Wilhelm Dames, who first describedthe Cambrian faunas of China.Formation and locality.?Middle Cambrian. Chang Hsia limestone.About 3 miles southwest of Yen Chuang, Shan Tung, China.Collected by Mr. Eliot T. Blackwelder, of the Carnegie InstitutionExpedition to China.
330 PHOCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.OBOLUS (LINGULELLA) ISSE, new species.
Ill form and size this .shell recalls 0. {L.) jxxjonlpensii^; it differsfrom it ill the form of the dorsal valve and the eharacter of the outersurface. The shell is rather strong- and made up of several thin layersor lamelUe. Its outer surface is marked hy concentric lines of growth,sometimes grouped in more or less elevated bands, and over all thereis a thin encrusting or scabrous layer that has a minutely granular,dull surface, somewhat like that of O. {L/tujnh'pis) gregwa but verymuch finer in its granulations or [loints. The inner layers of the shellare dark, shin}", and marked by concentric lines of growth and radiat-ing striaeForrnatlon and localitij.?Middle Cambrian. Near Cave Spring,Fish Creek Range, Utah.OBOLUS (LINGULELLA) ORUS, new species.This is a shell of the (). (Z.) iiumtlcaluti form, ))ut difi'ers from it inbeiii'^- more elongate; ventral valve more acuminate and dorsal valveproportionall}' larger. Its nearest allies in form are among the groupof narrow, elongate shells occurring across the continent at (^apeBreton. It difi'ers from all of them 0. (Z.) coUicia^ O. {L.)fiuiiiensis.^0. (Z.) caniw^^ etc: in having a thick, strong shell and usually moreacuminate dorsal valve. Tlie exterior surface bears ratlier strongconcentric lines of growth, and very fine, irregular, undulating, ele-vated strise that suggest the surface of O. ( Westonia) eUa^ when seenin a reflected light with a strong magnifier.This little shell occurs al)undantl' , l)ut good interiors have not beenfound. The main vascular sinuses appear to lie submarginal in bothvalves, and the visceral area of the dorsal valve narrow, extending alittle beyond the centre of the valve.Formation and local !ty.?Middle Cambrian. Limestones of theReagan formation, interliedded in the middle part of the Reagan green-sand, 15 miles north of Fort Sill, one-half mile east of Canyon Creek,Wichita Mountains, Oklahoma Territory.OBOLUS (LINGULELLA) PELIAS, new species.This shell most nearly resembles O. (Z.) deHideratun. It differs in thesquareness of the dorsal valve caused by the slightly curved sides andcardinal slopes. The ventral valve suggests the broader forms ofO. (Z.) desiderat us, and the dorsal valve those of 0. (Z.) /nosla and O.(Z.) ir'mona of the St. C^roix sandstone.The outer surface of the shell is marked by clearly defined con-centric lines that are slightly irregular, and narrow, fine radiatingundulations or costa? toward the frontal margins. When unusuallywell preserved, the surface also shows very fine, irregular concentric
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 331
striae between the concentric lines. The inner lamella of the shell aremarked by fine radiating- strite and the inner surface by more or lessnumerous punctse, ver}^ much as in 0. {L.) piinctatus. For its size theshell may be considered as relatively thin,A single specimen of a ventral valve that is doubtfully referred tothis species was collected 3 miles south of Antelope Springs, Utah, inlimestone forming- a spur of the House Range.Formation and locality.?Middle Cambrian limestones of FishSpring Range near north end; also a little south of the middle of therange, Utah.The exact stratigraphic horizon of the limestones carrying thisspecies is unknown. It is well up in the Middle Cambrian or in theUpper Cambrian.OBOLUS (LINGULELLA) QUADRILATERALIS, new species.General form rounded, quadrilateral; moderatelv convex. Surfacemarked by concentric lines and ridges of growth, with line stria?between. The surface of the inner layers of the shell is shiny andmarked by tine radiating strise in addition to the concentric lines.The shell is rather thin; it is built up of several layers.This species differs from other described species by its subquadri-lateral outline. In this respect it may be compared with (>. ( AYcstonki)chuaTen^u., from which it differs in having a thinner shell and differentsurface markings.Formation and locality.?Middle Cambrian. Coosa Valh\y shales.,Cedarbluff', Cherokee County, Alabama.OBOLUS (LINGULELLA) SEPTALIS, new species.The dorsal valve is all that is known of this little shell. There aretwo specimens in the collections of the United States National Museumand three in the collection of Mr. Bryan E. Walker, of Toronto,Canada.The general form of the valves is much like that of (). (Z.) rotanda-tus. It is distinguished from the latter and other described species bythe strong median ridge and septum of the dorsal valve. The outersurface is marked by concentric striee and lines of growth and veryfine irregular concentric striae that give a minutely rough surface.Formation and locality.?Middle Cambrian. Silicious shales, MountStephen, British Columl)ia.OBOLUS (LINGULELLA) UPIS, new species.This is a small, elongate shell of the group to which (>. (Z.) orasbelongs. It differs from the latter in being more elongate and in itsmarked surface characters, and from 0. (Z.) collicia, O. {L.)Jliimensis.^(). (Z.) canius., and allied forms, in having a thick, strong shell andhighly characteristic exterior surface.
332 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.The shell is thick, the anterior portions being made up of numerouslamella' oljlique to the exterior surface, in this respect resembling-some of the species of Olxdnx. having- thick shells. The exteriorsurface is mai-kecl by concentric lines of growth, with very line,somewhat irregular strije between them. These show very distinctlyon the anterior portion of the shell. Farther back they become veryirregular, giving a crenulated appearance to the stria3 and lines ofgrowth, and the surface looks as though it were formed of thin,imbricating scales or lamellae.The surface of O. (Z.) uph suggests that of <>. ( ^?estoni(l) euglypJms^but I have been unable to Und traces of the transverse lines character-istic of Wed<>ii/<t.Formation and locality.?Middle Cambrian. One mile west ofCherokee, San Saba County, Texas.OBOLUS fLINGULELLA) FUCHSI Redlich.Lmgidella fiichd Redijch, Pal. Indica, new ser. , I, 1899; Cam])riaii Fauna,Eastern Salt Range, p. 7, pi. i, tigs. lOa-e.In the collection received from Doctor Noetling 1 tind that thereoccurs in association with O. {L.)(rann!ecl'l a small, elongate form thatappears to be identical with L. fncJixl of Redlich, Doctor Redlichstates that his L. fucJisi occurs in hai"d clay a})ove the lower magnesiansandstones which rest on the shales containing (J. (Z.) iranniccl'l. Ifmy identification of the species is correct, 0. (Z. ) iranniecliho.^ '^igreater vertical range, or there may have been some error in identifi-cation and in the labeling of the zone from which the original speci-mens were obtained. The identification of the species in the materialbefore me is based on the form of the venti-al valve, as shown hyDoctor Redlich's figure 10c. Dorsal valves differ materially from hisillustration; but in another specimen a little pit mentioned l)y DoctorNoetling is shown, also two ridges that leave a concave hirrow in thecentral portion of the cast of the valve. These- are the lines of themain vascular sinuses.Format/on and locality.?Middle Cambrian. Zone of IJocferiajtoetling!, in dark argillaceous shales, Khussak, Salt Range, India.OBOLUS (LINGULELLA) WANNIECKI Redlich.lAmjulella icanniecki Redlich, Pal. Indica, new ser., I, 1899; Cambrian Fauna,Eastern Salt Range, p. 7, pi. i, figs. 9a-d.General form ])r()adly ovate, with the ventral valve obtusely accu-minate and the dorsal valve rounded subtriangular; convexit}" moderatein the specimens embedded in argillaceous shales. There is consider-able range of variation in the outline of the valves. The surface ofthe shell is marked by concenti-ic lines of growth and very fine, closelyundulating- raised striae that inosculate so as to give the surface a
NO. 1395. CAMBRIAN BRACHIOPQDA?WALCOTT. 333granulated appearance. This type of surface occurs on O. (Z.) isseand O. (Z.) upis. The anterior layers of the shell are marked by radi-ating and concentric striae, and the interior of the shell has scatteredpunctfe in addition to the radiating and concentric striaj. The shell isrelativel}" thick and formed of several layers or lamellaB in addition tothe very thin, outer, ornamented layer.The visceral area of the ventral valve is short, and the main vascularsinuses are about half way between the center of the shell and thelateral margins. In the dorsal valve the visceral area is well developedbeyond the center of the shell, and the vascular sinuses are fartherout proportionally than in the dorsal valve. The central and anteriorlateral muscle scars are placed on an elevated central ridge, on eachside of a sharp median septum.Observations.?This very pretty little shell occurs in great numbersin the dark argillaceous shales with Hoeferia noetUngi Redlich.Doctor Redlich states that it is the only species of the genus in thecollection sent to him. In the collections made by Dr. Fritz Noetling1 lind associated with Hoeferia noetUngi., O. (Z.) ivanniecki., O. (Z.)fuchsi, '' Mohergia-Acrothele ^m/??/^?/?" Redlich; also specimens of aspecies of Hyolithes undescribed.Among the American species of Lingulelki., O. (Z.) vmnnlechi maybe compared in form with 0. (Z.) zetus and O. (Z.) oioeni. Its surfaceis much like that of 0. (Z.) xijpis and 0. (Z.) ovus. It is distinct fromall described species when its form and surface are taken into consid-eration, as there is no species with its subtriangular form that has itsgranulated surface.Formation and locality.?Middle Cambrian. Zone of Hoeferia noet-Ungi. Dark argillaceous shales, Khussak. Salt Range, India. Theformations containing this fauna are referred to the Middle Cambrian,as there is no evidence that the Cambrian fauna of India above theupper Annelid sandstone, as described by Dr. Fritz Noetling and DoctorRedlich, is older.
. OBOLUS (LINGULEPIS) EROS, new species.Ventral valve elongate with rostral slopes gradually converging soas to form an accuminate beak. Surface marked l)y tine concentriclines of growth and very tine, somewhat irregular, concentric stri^.Rather large scattered puncta? occur on the interior surface.This species is represented by fragments and two broken ventralvalves; these indicate a length for the ventral valve of from 7 to 10 mm.It is allied to O. {Llngulepis) acurnlnafm v^eeksl of the Middle Cam-brian fauna of the Teton Mountains of Wyoming.Formation and loc<dlty.?Middle Cambrian. Chang Hsia limestone.Three miles southwest of Yen Chang, Shantung, China.Collected by Mr. Elliot Blackwelder of the Carnegie Institutionexpedition to China.Proc. N. M. vol. xxviii?04 22
334 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.OBOLUS (LINGULEPIS) ROWEI, new species.In outline and convexity the valves of this species are closely relatedto those of 0. {Luigulepis) acuminatum. It differs from the latterand other described species b}^ the strong, raised, concentric lines,Avith very imperfectly defined fine striae between them.The specific name is given in memory of Mr. R. B. Rowe, assistantgeologist, who collected the material representing this species a shorttime before his death.Formiition and locality.?Middle Cambrian. Reddish-brown sand-stone. Resting Springs, Inyo Countj^, California.OBOLUS (WESTONIA) ALANDENSIS, new species.Lingida.'' !^p. No. 2. LhiguleUa ? sp. Nos. 3 and 5. Wiman, Bull. Geol. Institute,Upsula, No. 2, VI, 1903, Pt. 1; Studien Nordbaltische Silurgebiet, p. 52,pi. II, figs. 33, 35, 39.This species is characterized by its l)road form when compared withO. { Weston m) hottiiica^ O. (Westonia) wimani, and O. ( Weston ia) hal-tica. Its surface is marked by fine concentric lines of growth, withvery fine, thread-like, concentric strijB between them. Under a strong,reflected light, almost microscopic, transverse, very irregular linescan be seen that give the surface somewhat the appearance of that ofO. ( Westonia) ella.Formation and locality.?Middled Cambrian. Gray, bituminoussandstone in drift bowlders on Aland and Biludden shores of GefleBay, Sweden.For reference to geological horizon, see description of O. ( Westonia)hottnJra. OBOLUS (WESTONIA) BALTICA, new species.LiiiguleUa f sp. No. 4 and 6. Wiman, Bull. Geol. Institute, Upsala, No. 2, VI,1903, Pt. 1; Studien Nordbaltische Silurgebiet, p. 52, pi. ii, figs. 34, 37, 38.This species is characterized by its elongate form, with the sides ofthe dorsal valves regularly rounded from the back to the roundedfrontal margin. The dorsal valves are also more regularly andstrongly convex than in other species occurring in the Cambriansandstones of Sweden. The outer surface is marked by concentricand radiating stria?, crossed obliquely by very fine, irregular trans-verse striffi. The latter are only to be seen with a strong magnifierand favorable light.Formation and locality.?Middled Cambrian. Gray, bituminoussandstone. Drift bowlders at Biludden, shore of Gefle Bay, andSkalstenarne. Also near Ofverb}' in the "Gemeinde of JomalaAland.''
NO. 1395. CAMBRIAN BRACHIOPODA?WALCOTT. 335OBOLUS (WESTONIA) BLACKWELDERI, new species.General form elongate, with the width about one-half the length;front margin broadly rounded; sides slightly arched up to the lateralslopes which are quite straight in the ventral valve and curved towardthe rounded posterior end of the dorsal valve; the beak of the ventralvalve is pointed and marginal. The convexity of the valves i*.s mod-erate, that of the dorsal apparently being the greater. Surfacemarked by concentric strife and lines of growth which are crossed byirregular, fine, imbricating, more or less transverse lines; the trans-verse lines trend slightl}' backward toward the sides of the valves.A dorsal valve 8 mm. in length has a width of 5 mm.Ohsei'i^ations.?Nothing is known of the interior of the valves.When the shell is broken from the limestone, the outer surface usu-ally adheres to the matrix. The best exteriors are those of shells onthe surface of the layers. Of the known species of Westonla^ 0.{W.)wimani and 0. ( ^Y.) haltica are most nearlj' related to O. ( W.) hlacJi-welderi. The latter is a larger shell and also less narrow proportion-ally where the gently arching sides pass into the postero-Iateral slopes.Formation and locality.?Middle Cambrian. Chang Hsia limestone.Two, and two and one-half miles south of Yen Chuang, Shantung,China.Collected by Mr. Eliot Blackwelder of the Carnegie Institutionexpedition to China.OBOLUS (WESTONIA) BOTTNICA Wiman.Lingula hottnica Wiman, Bull. Geol. Institute, Upsala, Xo. 2, VI, 1903, Pt. 1.Studien Nordbaltisehe Silurgebiet, p. 51, pi. ii, figs. 40-4-1.The description of O. {We-stonia) finlaiidends so closelv applies tothe description of this species that it is only necessary to point out thedifference between the two.The surface of 0. (Weston la) hottnica has the same concentric andradiating lines, with the irregular transverse lines terminating at rightangles to the margins, curving inward and backward in such a manneras to obliquely cross the radiating lines that extend from the umboforward to the anterior and antero-lateral margins. The central scarsof the dorsal valve are much further forward in 0. ( Westonla) hottnica.Formation and loccdlty.?Middle? Cambrian. Coarse grained,somewhat friable, glauconitic sandstone, drift bowlder No. 3 onEggegrund Island, North Baltic.Dr. Carl Wiman refers this species to the Olenellus sandstone series.The bowlder containing it also carried Aparchltesf andet^smni.^ Hip-jyonicTiarlor niattheivl, Acretreta eggegrundensls., Kvtorginaff U^relleUaIsevlgata, and fragments referred to Olenellxis. This fauna is essen-tially Middle Cambrian in its facies, and unless the fragments referred
336 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxviii.to Olenellus are indisputably of that genus, 1 am inclined to refer thebowlder and its contained fossils to the Middle Cambrian. The factthat O. ( Wesstonia) hottnica is nearly identical with 0. ( Westonia)Jinlandeni<is of the Paradoxides tessini series of Finland, also pointsto the Middle Cambrian age of the fauna.OBOLUS (WESTONIA) IPHIS, new species.This shell differs from all other species of Westonia in having a moreelongate and accuminate ventral valve, and in the presence of a markedmesial depression on the dorsal valve. The shell is rather thin andmade up of several very thin layers or lamellae. The outer surface ismarked by line radiating stride, concentric strife, and lines of growth,and fine more or less undulating, transverse lines that cross both theradiating and concentric lines. The transverse lines appear to be theedges of slightly elevated imbricating lamellae of the shell.Formation and locality.?Upper Cambrian and Ordovician. LowerOrdovician Pogonip formation, Hamburg Ridge; also near the BuU-wacker Mine, in the Upper Cambrian Eureka District, Nevada.OBOLUS (WESTONIA) THEMIS, new species.General form subsemieircular, with the ventral valve subaccuminateand the dorsal valve broadly ovate in outline. Valves rather stronglyconvex. Surface of the shell marked by strong concentric lines ofgrowth with finer intermediate striae; in addition there are ver}^ fine,irregular, raised, more or less transverse strife that inosculate, form-ing a minutel}^ papillose or granular surface much like that of O. ( IF.)ella. It often occurs that the outer surface has been removed by attri-tion in the sand, so that the shell has a smooth, polished surface.Owing to the condition of preservation, the markings of the innerlayers are not preserved. The shell is strong and thick in advance ofthe center. It is made up of the thin, outer surface laA^er and severalinner layers, as lamellas, in the posterior portions that are slightlyoblique to the outer surface. After the shell has attained a size of 2or 3 mm., the lamelhe are more oblique to the outer surface and forma thick, strong shell, the outer edges of which often produce a ratherrough surface.The largest ventral valve in the collection has a length and breadthof 10 mm.; a dorsal valve 10 mm. in length has a width of 11 mm.The onl}^ interior portion of the shell known is on a fragmentary^ ven-tral valve, in which the visceral area does not reach the center, andthe main vascular sinuses are about halfwa}^ between the center andthe lateral margins of the valve.Oh^ervations.?The general form and character of the shell is muchlike that of 0, lojperi. It differs from the latter in surface characters.
N0.1395. CAMBRIAN BRACHIOPODA?WALCOTT. 337Formation and locality.?Middle Cambrian. Solomon Formation,235 feet above Tonto sandstone, Grand View Trail, southern side ofGrand Canyon, Arizona.OBOLUS (WESTONIA) WIMANI, new species.Lingula f sp. Nos. 1 and 2. Llngulella f sp. No. 7, "Wimax, Bull. Geol. Institute,Upsala, No. 2, VI, 1903, Pt. 1; Studien Nordbaltische Silurgebiet, pp. 51,52; pi. II ; figs. 30, 31, 32, 36.The general form of this species is not unlike that of O. ( Westonia)hottnica. The cardinal slopes of the ventral valve are more rounded,which makes the valve broader near the center. All of the specimensare also smaller. The surface markings are of the same character asthose of (). {Llngulella) jTnlandensii< unA 0. (Westonia) Ijottnica.It is not improbable that with the discovery of a large series ofspecimens the three species may be combined, or O. {Westonia) hott-nica and O. { Westonia) wimani placed as varieties of O. { Westonia)Jinlandensis.The species is named after Dr. Carl \Mman.Formation and locality.?Middle 1 Cambrian. Fine gra}^ sandstone,drift bowlders at Biludden, shore of Getie Bay, Sweden. For referenceto geological horizon refer to description of O. { Westonia) hottnica.