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Les diagrammes suivants iliustrent la m^thode. errata I to t i pelure, on d i 13 1 2 3 4 5 6 32X I'iy s c '/ ..J )"vr GEOLOGICAL SURVEY r \u . m STATE OF WISCONSIN, -^ir 1859-1863. PALEONTOLOGY. ^# , PART THIRD. * "f '■*«» / / ► . t r sen •' wo or kn( as "I cor r as ■ • ■ pel Ra of th€ pre Le des nu th( ore of . roc pr( ■ •• ex ' by wl *- an *.■- # '■ on Pri - i -" ■ -!;; - i^ \ 1 ( 1 « I < « S ' ' ' , t ^ B r c 6 e « « = - * 4 V ■ ^-^i^' -.-: ' ' If 4- 1 --■ ^ '. ,.. -.*-.'. •-i/'V'*', "}''\ *«^ "" ■ 'i *»■ ', The Report upon the Geology of Wisconsin, already published * pre- sents, in an introductory chapter, a concise history of the origin and working of the Survey, to the time of the publication of the volume, or to the close of the year 1801, The name of the writer, without his knowledge or solicitation, was incorporated in the original Act of 1857, as one of the Geologists, and by a subsequent Act of 1860, he was made " Principal of the Geological Connnission," and directed to make certain contracts, etc. The work of the Survey, in its several departments, was carried on as rapidly and as successfully as the organization, required by law, would permit. The volume already published, was communicated to Governor Randall in December, 1861, and copies were distributed to the members of the Legislature, in February following. At that time the work on the Palaeontology was well advanced, and required only the means for providing illustrations, as then stated, to be ready for presentation to the Legislature, preliminary to publication. Many of the new or little known species of fossils had already been described in one of the Annual Reports. Drawings of a considerable number of species had been tuade, and two plates illustrating fossils of the Trenton Limestone, had been engraved at the writer's expense, in order to show the character of the work contemplated. Large collections of soils, rocks, minerals and fossils had been made and deposited in the rooms of the University buildings. The want of suitable cases only, prevented these collections from being arranged, thus presenting an exhibition of the mineral and agricultural resources of the State, and by this means laying the foundation of a scientific and practical museum, which might have been of great utility to the students of the University, and the people of Wisconsin generally. ♦Report on the Geological Survey of the State op Wisconsin. Volume I. James Hp,ll, on general Geology and Palseontology, and J. D. Whitney, on the Upper Mississippi Lead region. Printed by authority of the Legislature of Wisconsin, January, 18G2. I s^ ■"^' Notwithstanding all this evidence of progress, and with copies of the lirst volume in its hands, the Legislature of 1862, in violation of the provisions of the Act of 1857, and in violation of contract stipulations, made expressly under the provisions of the Act« of 1857 and 1860, repealed the laws and suspended all appropriations for the work. Since that time, repeated applications to successive Legislatures have met with a steady refusal to refund to the writer the money actually expended by him for the purposes of the Survey, or to pay for his own services per- formed according to the conditions of his contract with the Governor of THE State of Wisconsin, under the laws already cited. Under these circumstances the " Sup3rinteHdent of the Geological Survey " has been compelled to seek a publication of the results of his labors elsewhere. The investigations upon the Potsdam Sandstone, with descriptions and illustrations of the fossils of that formation in Wiscon- sin and adjacent parts of Iowa, have already been published. The work upon the fossils of the Trenton and Galena Limestones ; of the Hudson B^ver Group, and of the Devonian Rocks of the State, is in prcnrress, and the results will appear in due time. The present, is the third in order, of a series of papers resulting from the study of the fossils of the Geological formations of Wisconsin. J. H. JamMry, 1871. opies of the ation of the stipulatioiiH, and 1860, rork. Since ive met with expended by lervices per- GrOVERNOR OF e Geological esults of his idstone, with n in Wiscon- . The work ' the Hudson in prc,i;re8S, the third in fossils of the ORGANIC REMAINS OF THE NIAGARA GROUP AND ASSOCIATED LIMESTONES. liy JAMES HALL. 1. RELATIONS OF TH7. NIAGARA GROUP WITH THE LECLAIRE, RACINE AND GUELPH LIMESTONES. J. H. In the study of the fossils of the Niagara group and associated strata, previous to the publication of the final Report on the Fourth Geoloyicul District, and also to the publication of the second volume of the Palwoiitology of New York, I separated a few species found in the impure drab-colored limestone from Wayne county, New York. The limestone containing these fossils became exposed only in the bed of the canal during its excavation ; and the low country, or deeply drift- cuvered surface m the vicinity, did not admit of any exposure of the rock in place. The materials were thrown out of the excavation in connection with the soft marls of the Onondaga salt group, and the specimens of rock containing the ibssils preserved the peculiar cellu- liferous structure and characteristic color of the argillaceous limestone of that formation. Differing so essentially from any known beds in the Niagara group, I did not hesitate to refer them to the Onondaga salt group, since there was no evidence of any other formation in the neighborhood.* ♦The same reference of the specie ■; had, in fact, been made during the Geological Survey, and thej were thus published in the Report on the Fourth Geological District, in 1843. ■'3 -i-. Tliiou-lmut tl.e State of New York, the country aloiig the jimctM.n of the Nhiguni an.l Ono.ula^a silt lorinatioUM is low ami level, or covered by drift accuMudatious ; and no opportunity olVered of d.sc.vern.j-- any exposure ..f si.iilar h^'d. along- the course of the out..'op. In some places \n Monroe county we have heen al.ic to trace the two forniat..m« to within a few feet of their contact with each .,ther ; hut no fossd.lerous beds similar to those of Wayne county, have heen found. Subse.iuently after'a considerable portion of Vol. ii of the Pakvnntnhyj of New i orh had been printed, my attention was called to some peu ll>e,dn,o induoe.l to hcli-v. tin,! to- Innc.toue ,„ „,„a,u., tl,o nm»» ut UrUir. an,l .xtculing tlu.,,,.. ioto lowu, a« w.U „« thu (i.K.ll,h lonnution in Cumdn Hn,! tl... lW.|,lc ropre.cnt^t.on ol the .„„e in New York, arc really Icnli.ular n,a«e« of greater or L.s extent, „|,icl, have accnnulated u,on the nne.,ual .urli.ee ..f th,. ..eean he, n, a .hallow .e,. .Inring the latter pa.t of the Niaga.'a ,,er,od lhe.e ,.„ t, „,a,ses of Ihoestone h.ue cl„«o reh.tions with ea,l, other, wh.le the,, ..elations with the Onon.laff. .alt grou,,, tl,o„gh ve,y ,nt„„ate >„ the .ingle h,eality in Central New York, l,eeo„,o le.» ,«,a le«» con.i„en,.,.s >n a westerly direction. , , ,. . In .l,e'G.W«,./ r, /., U„l>li.ln.d in 18««. tY\ ^ ' W I'C" a,.e ,leseril,ea a» constituting a Uistinet lorn,at,o>, ; h„t b,r. W . h. Lo,.an remarks : .It has nhva.b l....n sla...l tl.al tla- strata s...u .uar tlu- "'^'"^iM-ni. It l,a,s am a ^ i,,ol,al.ly strike along the coast l.y Lyi'U IJivi.-re aux N.hK'^, at C ill 1 . 1 oiiu j lonnation, whose r -. 1 1 K- 1... il.<. form of a -real eiiticiilar mass, the limit ,.iwl 111 C'lU'idait i)rol>ah V lla^3 llie loiui oi .ij^iv , vl e h t„, Kiaga,a a„.l ..a-l,.!, i^ "-c.ai,,, ,l,o,„l. i. •'W-- " ^ ^f ,' „„d A„ea,.e,-. In tl,e ,„l,e,- ,li,ve,i..„, it .ee,„., ,.; ,1.„. out n. Lake ll,no„, l,er.>,e rcaeliiag ll,e uorlliern peniusala ol Michlga.,. I should not omit to «,y here, that .,o liir a« n.y i„ve.tigat,o„» have extended on the islands of Lake nu,-on and Lake Michigan, w,th the pen,n- ,ula between the hitter and Green Bay, 1 have found the presence ol he l^werportior^of the Niagara group, with the general absence of the h,ghcr Ueds At the s.r,ne ti.ne, along this great extent few fossds occur excei^ V.Uumerus oUon,.,s, m,A. cutc.Mus,.^ two spec.es of i vvoshes^ with some other corals ; and it is only on continuing the o"^; ™' "- «« e southward in Wisconsin, that we llnd a larger mnnber ofthe N agau. «c es proper This indication of beds of passage, pointed out by S,r Te Loi:, will, I presume, be found in all or .rearly all localities where a junction of the two formations can be seen. )eH not mtpi'ar :hi8 limestono luwii, ar< vvL'll utiitionol' tlio jr l«'Hs exU'nt, ict'iin bi'd in a riu'se ifiolati'd r, while their itiiiiiite in the eon^ipicuous in \[)\\ liincstonert . \V. E. LOOAN If nidiilh of till! coast l)y L>»'U oniiiitioii, whose 11' slioi'i', Tlii'sc r.s of the Uuc'li»li uiusuNiA have ii uratomaria huvo- Lslaiul iissoi'iiiU'd I'C'ii'S ; so thai it may constitute a .te of New Yoik; IV mass, the limit iippeais to extend 1 ill Lake Huron, estigations have 1, with the penin- 3 presence of the iiiceoi" the higher isils occur except cs of Favosites, ,e observations to )er of the Niagara )inted out by Sir arly all localities II. DKsnni'TioNS or kossils hf tiik mai;\|{a uKori'. ECHINODERMATA. In the Report of VroyirHS of the Oi'ntoijh'nl Siinrij of W'iseoii.siii for 18(11),* I (les(M"i))ed several species of Crinoidea, two Cystidean^, several species of lirac.hiopoila, (rasteropoda and (Jephalopoda, from the limestones of Racine and Waukesha; leaving a considerable numbor of species unde- scribed for want of satisfactory material. It has not been in my power to make such collei'ti(ms as I then anticipated ; and the Ibllowing descrip- tions reliite almost exclusively to species that have been in my cabinet for several years, and which were studied, and many of them determined, at the time of making the report a))ove cited. Some of the Crinoidea are very interesting ; but the Cystideans possess a peculiar interest, as olVering formes which, so far as I know, have not been discovered in any other localities. The specimens, with few excep- tions, are casts of the interior of the test, or impressions of the exterior left in the matrix. A few of the species retain the plates to such an extent that the structure can be determined. Since it appears probalde that we shall, for some time at least, be dependent upon similar imperfect materials for our knowledge of these tbssils, I shall endeavor to give stich descriptions as will enable the student to recognize the species, with the hope that some of them at least will be illustrated at a future period. GENUS GOMPHOCYSTITES, N.G. [yo/iijioo, ciffDUs; Kvaioa, vesica.'} Body elongate pyriform, very narrow at the liase, gradually enlarging above, and inflated near the upper extremity. Surface composed of numerous series of polygonal plates which have a spiral arrange- ment. Apertures upon the upper surface, one of them l)eing subcentral, and the other a little eccentric. Arms sessile, lying in grooves excavated in the surfixce of the plates, originating near the • Report of the Superintendent of the Geological Survey, Legislative Documents, 1861. „,„utl,, .ml curving sim-ally outwards nnJ ,Unvn»ardH over the body, rcachina to or even below the point of it.s greatest d.ame er The een'ral aperture appears to have been closed by a pyraund of (ivc or six small plates. The li,«ilsof this genus are re.narUable for their elongate form, attenuate base and swelling upper extre.nity ; they were prol,ably supported upon a short pedieel, hut we do not know its eharacter. The body .s eon.posed of numerous ranges of short hexagonal or polygonal plates the spn-al unangeuient of whieh eau be traeed in their marking upon the east. In a fragn.ent of one of these fron, the Niagara shale ol New \orK, there is but a single subeentral opening visible, the arn.s all or.gn.a Ung „„ one side of this. In the easts of other species fro.n \\ .seonsn,. there is evidence of a sn.aller aperture near the round subeenti-al one. A large proportion "f the specimens observed are unsymme neal m greater or less degree, and this leature is apparently very variable .n the same species. In a view of the sunnnit, the position of the apertures^ „ud disposition of the arms resemble Auelacuinus, but the plates are of diifereut eharacter, being str, ,gly granuloso, and the sutures of the plates ;u-e so close as to make it diltleult to distinguish them. GoMrnOOTSTlTES TEXA.\, s. s. PLATE XII. I'la. 13; ri.ATi.; xii ... iios. i. 2. Upper part of body ventricose, somewhat rapidly attemiated below , principal aperture round, subeentral; the pyramid of plates whieh probably closed the orifice are unknown, leaving a margm of small unequal plates. The plates forming the svmniut of the body are small, polygonal, with surface strongly gratudose. The arm-plates appear to have been furnished with tentacula, as in Apiocystites and other genera. - Fonualion and Xoc'«%.-This species occurs in the Niagara group at Lockport, New York. Collection of Col. E. Jewett.* GoMPIIOCYSTITlv"' GLANS, N. S. PLATE XII, FIG. 11 ; PLATE XII a, FIGS. 4, 5. Body elongate, clavate, with the upper extremity extremely ventricose, often more or less unsymmetrical, and the summit unequally convex on the upper side, somewhat abruptly contracted below, and thence * Now in the collection of the Coruell University. 1 9 "i? I'ds over the est diameter, a pyramid of rm, attenuate ported upon a Y is composed ^es, the spiral m the cast, of New York, ill originating isconsin, there I one. ymmetrical in variable in the the apertures e plates are of es of the plates muated l)elow ; of plates which nargin of small if the body are The arm-plates in Al'IOCYSTlTES fiagara group at gradually attenuate. Principal aperture subcentral ; arms originating close to the aperture, and curving in a, spiral direction over the sununit and along the sides to the point of [greatest expansion, or sometimes a little below. The specimens of this species n from one to three inches in length, with a diameter in the greatest expansion of i'vn less than half an mch to an inch and a hall'. The illustrations are of a large unsymmetrical specimen, and one of symmetrical fovm somewhat smaller. Fonnation '.ml Lomlii//.— In the limestone at Racine, Wisconsin. GoMrilOCYSTITKS CLAVUS, X. S. rLATlC XII («, FKi. :i. Body clavate, gradually expanding to the upper part which is elongate ovate, nearly or quite symmetrical, summit regularly convex; prin- cipal aperture at the apex, and essentially central. Arms originating from one side of the central aperture, curving a little spirally down- wards, and reaching below the apex a distance about equal to the greatest diameter of the body. Below the expanded portion, the body becomes obtusely pentagonal, a feature but obscurely shown in the cast ; base unknown. This species is very nearly symmetrical, and nuich more gradually expanding from below^ to the greatest diameter, and less abruptly rounded above ; while the arms have a more nearly vertical direction. It i!5 possible that this may be only a modification in form of the 0. glans; but among a considerable number of specimens of that species, I have not observed gradations to this form ; and 1 therefore designate it as a distinct species until it can be proved identical, or until its relations with the preceding species can be more satisfactorily determined. Fonnation and Local Uf.— In the limestone at Racine, Wisconsin. mely ventricose, inequally convex elow, and thence GENUS HOLOCYSTITES, x. g. I' oM tolas; Kvaro^, vesica} Body elongate, sub-cylindrical, elliptical or sub-ovate, composed of numerous (six or more) ranges of comparatively large plates, or of alternating series of large and small hexagonal or polygonal G. \V. S.iV 10 plates; apertures at or near the sunnnit, one of them central or Hubcentral, the other eccentrie. Supported on a ^hort ped..el Sessile arms none ; Iree arn^s unknown ; no evidence ot pectnutted rhombs. The specimens relerred to this genus are generally composed of large plates in pretty regular alternatiug series, or sometimes a range ot }arody from the summit, and at tlie point ot greatest diameter. In the sixth range a,l>ove the basal, the plates are ,nuch smaller than the others, and narrower at the upper end. Alteruating with these last, is a seventh range of smaller plates, surrounding those of the summit, and enclosing the summit openings. Column small, round, rapidly Uvpering below the point of attach- ment. Surface of plates granulose. . ^ ,„l aeolo,ical I<,>oriof msconsin for 1800, published 1801 ; and GeoU>,y of msconsin, Vol. i.p.Cy. 1802. glV evi in grii ha' Wi Be ti rti re B T I ccntr.il or ort ped'uel. f pectinated »sed of large a range of re no indica- ly have l)een urface of the s and central to the genus IS shown that genus, and I 800, p. 23. 1801. and abruptly 1 ; basal plates [o-e consists of id a half their i\o\\ upwards ; fifth range of il, their length )urth range is one-third the int of greatest the plates are ;he upper end. smaller plates, imuiit openings. )oint of attach- 'eoloiryof Wisconsin, 11 .•*,v?' Several specimens, more or less entire, exliihit the characters here given. While the surface of the plates is coarsely granulose, thei'e is no evidence of ridges or nodes. Some of the specimens show irregularities in the form and proporticms of the plates, indicating the possihility of a gradati« nore of the ir riuij^os of oe iind CM[ual iigiini group mit a])i'uptly is unknown. The form is late, perhaps the aperture eight ranges lating series; lie arcuation, on, which are rom becoming upper straiglit leding ones by as ranges and icession. The resemble those s impossible to upwards, since teen or sixteen :ie side. ength of aljout more than half ^ing its greatest ameter a little iigara group The two following species, l)oth on account of their form nnd the great numl)er of small polygonal plates, may prove distiuct froiu the typical forms of this genus : * HoLOCYSTITKS ()\ VTUS, N. H. rr-ATK XII, I'lo.a. Body from the summit to near the base symmetrically ovoid ; a little depressed at the central aperture, and elevated at the eccentric one ; sides regularly curving; composed of more than ten ranges ol alter- nating polyg(mal plates, which are as wide as long, or wider, elevated in the centre, and coarsely granulose. A specimen of one inch and three-fourths in length, and perfect at the base, shows ten ranges of plates between the broken lower margin and the sunnnit aperture. The greatest diameter of the same individual is one inch and a half, while it is about half an inch in diameter where broken oil', and there have probably been two or three ranges of plates below that point. A section below the sunnnit is very broadly elliptical, and this has probably been the original form. This species dillers from 11. scutellatm in l)eing a more robust form, with less elongate base, and with plates larger, more equal in size, and prominent in the middle ; while the larger plates in that species have central nodes from a nearly ilat sm-face. Formation and Locaidi). — In the limestone of the Niagara group at Waukesha, Wisc(msin. HOLOCYSTITES SCUTELLATUS, N. 8. 1>LATK XII. FIG. 1. General form of body ovoid ventricose, abruptly attenuate below, and swelling above into an ovate outline; composed of twelve or more ranges of plates, which are somewhat irregularly disposed, there being in the upper part a distinct arrangement of one large polyg al plate surrounded by smaller ones, this large plate having a node in the centre. The sunnnit is broadly rounded, with evidence of one large subcentral aperture, and a depression indicating a second aperture. Surface of plates strongly granulose. The ventricose ovate form and abruptly attenuate base are distin- guishing features of this species. Though the //. cijlindrkus sometimes T ii* 14 assumes an ovate lorm witli attenuate base, yet the speeiuH hero tloscrihed has a uuieli larger number ol' plates, whieh are dilVerenth disposed. Fanmthn ,tm/ Locum//.— In limestone of the age of the Niagara group at Waukesha, Wisconsin. GENUS APIOCVSTITES, Fokhes. Ai'iocYSTrrKS imauo, n. s. 1*1, ATI-: XII, KUi. IJ; I'l.ATK XIlo, llti.il. Body irregularly elliptical, about three-iifths as wide as long, a little larger above than l)clow the middle. Basal plates occupying more than one-lburth oi" the entire height of the ])ody. Second range consisting of live large plates. In the thud range the plates are about bait' the size of those of the second range. The fourth range consists of at least six plates ; the two over the ovarian aperture are smaller than the others. The lifth range consists of six plates of smaller size than the others, and of a pentagonal form, the upper margins being determined by the number of apicial plates, which are unknown. The ovarian aperture is situated over the right superior angle of the hexagonal basal plate, and the space is exca- vated from the upper margin of the plates of the third range and the lower margin of one of the fourth range. The pectinated rhombs upon the right side of the ovarian aperture occupy the adjacent margins of two plates, and are on the same parallel with the aperture. The other pectinated rhombs are not preserved in the specimen. The plates of the four lower ranges are longitudinally ridged in the middle, and in their perfect condition have probably had a central node. The circa-ovarian plates, and those of the centre of the summit or apex, have not been determined. The specimen described is a cast, but so well preserved as to indicate very satisiactorily its most important characters. It is a more elongate form than any cystidean of this group (i^seudocrixites, Apiocystites, etc.) that I have seen from American rocks. Formation and Localitu .—In the Racine limestone of the Niagara group at Racine, Wisconsin. I T" * herode.sci'ihed y diispc^-iod. IS long, a little occupying more Second range I the plates are 'he fourth range ian aperture are of six plates of Ibrni, the upper 111 plates, which over the right le space is exca- third range and The pectinated ture occupy the ne parallel with preserved in the re longitudinally 1 have probably lose of the centre ed as to indicate a more elongate 5S, Apiocystites, tie Niagara group I 16 CJKM'S IIIvMKJOSMITKS, VonBi.ii. This genus was establislu-d l)v \'()x Bvni for a Ibssi' Hy;ured bv I'am.kij under the n;nne of /'Jc/iinn-sji/Kvn'ffs Dixhiiii. The body consists of four series of plates ; the basal series containing lour plates, of which two are hexagonal and broad, and two narrower and pentagonal, similar to tliost' of C.vuyocui.ms. The second or subradial series consists of six plates, which are likewise very- similar to those of Cauyocuinus, except that three, instead of two, are truncated at their upper margins; and two of them are exca- vated on their upper adja(;ent lateral angles lor the ovarian aperture which lies between these and the base of one of the plates of the succeeding range. In the third range of jjlates this genus dilfers from Cauyockixcs in having nine instead of eight plates; the ninth comes in by a truncation of a plate of the second range, which corresponds to the plate directly opposite the ovarian aperture of the other genus. The mouth is represented by Von Bucn as central. It is not known to possess arms or tentacula. Among the fossils of the Niagara group in New York are some sepa- rated plates which I have supposed may belong to this genus ; but their relations have not been fully established ; though I have little doubt that further examinations in some of the more prolific localities will show the occurrence of this genus. Among the cystideans of the same group in Wisconsin there are several 'specimens which preserve the structure and general features of this genus ; l)ut they are for ilie most part obscure. Hemicosmites subglobosus, n, s. PLATE XII, FKJ. 13. General form subglobose, a little longer than wide, somewhat narrower above than below ; the ovariaxi aperture above the middle of the length; scarcely produced at the base, which is sometimes sub- ti-uncate or even a little depressed. [This latter feature is probably due to accident.] In the lower range the plates are short, and the second range consists of comparatively wide plates, giving it a greater proportional width than the typical species of the genus. The mouth is at the summit, but it cannot be determined whether it is or is not 1« prul)osei(lil()im. The ovariiin aperture is situated above the second range of plates, and is apparently more nearly at the sununit of the Platte on the vi^dit, wliieii has a soniewliat dillerent lorni from the corresponding ->l<'*e in Uruncnsmites pi/iijhrmis. The plates oi" the body are granulose and marked by stria3 parallel to the margins, having the centre elevated in a low node iVom which there are radiating ridges to the angles of the plate. /■'unmilioii m<1 Localif//.— In the Racine limestone of the Niagara group, llacine, Wisconsin. Among the collections from llacine, and associated with the preceding mpecies, there are several specimens of a peculi^ii form, apparently cysti- deans, but of dillerent structure from any (]escril)ed genus, which, from the nodes or spines upon the surlivce of tho species known, 1 propose to name Eciiinocystites. GENUS ECIIINOCYSTITES, n. o. Body subspheroidal, composed of four ranges of plates. The l)asal plates are probably four, and are succeeded by two ranges of live plates each and a "series of dome plates. The mouth is central, with an eccentric or lateral ovarian aperture. EcHINOCYSTrrES NODOSUS, N. s. I'LATK XII, FIG8. 10, 11. Body subglobose, base slightly protuberant in the centre ; Dasal plates short. The live plates of the second range are large, fornnng part of the basal curve, and extending up the sides; they are furnished with strong nodes which are directed obliquely downwards. In the third range the plates are of equal size with the second range, and nodose in like manner; the sides of the body between the nodes being nearly straight in the vertical direction ; the nodes of the lower range project a little beyond those above. Number and form of the sunnnit plates not determined. There is evidenc^^ of a central aperture, which is probably the mouth; while at the upper lateral angles of two adjacent plates of the third series, and succeeded by a plate of the fourth series, is situated the ovarian aperture. The specimens examined are casts of the interior, some of which retain parts of the test, and preserve, in a greater or less degree, marks of the structure. 17 ,1X/ K)ve the second L' .suininitor tlie , lurm troiu tlif 10 plates ul" the ;o the luiirgins, Audi tliere ure iNiiigiirti^Toup, ;h the preceding ipparentl} cjsti- lus, which, I'roni svn, 1 propose to Tlie basal plates ;es of five plates central, with an tre ; uasal plates rge, forming part tiey are furnished vvnwards. In the econd range, and jtween the nodes the nodes of the Number and form idence of a central the upper lateral and succeeded by 1 aperture. me of which retain ;ree, marks of the Fnnnation ami Lnaditij, — In the Kat-ne limestone of the Niagara group, IJacine, Wisconsin. The tw<' (bllowing spocie^* I place among the Cy«tida3 wilh some iicsita- tion, notwithstanding the unsynnnetrical form and peculiar character of OIK' of them, which closely resembles in its general features the IIoi.o- t.'YSTrnos. In many of the Crinoidea proper, we find the [)lates arranged in suc- cessive order of one, two or three toUowing each other directly in what are termed the radial series ; while between these rays are interradial plates in the usual order of a larger one below, which supports two plates in the second range, followed by a like or greater numl)er in the third range. In the Cystideans of the described genera the plates do not follow this order of arriingement, and cannot be separate] into radial and interiadial sei-ies, according to the usual mode in Crinoidea. In the Cystideans, where there are a considerable number of |)lates, tiiey are arranged in alternating order, so that each succeeding range above the second have their lower margins more or less pointed and inserted partially between and resting upon the sloping upper faces of those of the preceding i-ange. This feature is seen conspicuously in IIolooystites, where the plates are ni iverous. It sometimes happens, that owing to a curving f()rm the plates follow each other in direct order. Among the specimens which I had provisionally placed among the IloLouYSTiTEsisasmall species of unsynmietrical, sub-clavateform, havin<-' the two lower ranges of plates alternating as in that genus, while above these the plates are arranged in consecutive order, until we reach the last range, where every alternate one is omitted, thus producing a con- traction of this part. '^hice this form cannot be consistently referred to an}' described genus I propose the name Crinocystites. GENUS CRINOCYSTITES, N. G. Body elongate, composed of plates of sub-equal size. The number of basal plates undetermined. These support five hexagonal or Iiep- tagonal plates in the second range, and upon thu upper edges of these, three plates of similar form follow in direct succession; and upon the third is a fourth plate supporting one or two arms. Between the upper sloping faces of the plates of the second rano-e, G. w. 3 .u^ .18 tlu'ir is insiTt.Ml ii |u-Mta;inniil plate, winch supports a r.xw^c in diroot succession of two or tluve licNnj^oniil pi. tes. The summit is unsym- nu'trical, and in one specimen there is an apparent central aperture or mouth, and an eccentric or ( • aperture; and the mar;-in is marked hy what api)eurs to he tne ..uses of slend»'r arms or tentacula. Such a structure, in the ordinary nonu nclature of the Crinoidea, would )„. dcscrihed as a range of l)asal plates, succeeded hy a radial series of Hiur or live plates. The distinctly unsymmetrical form of one of the species having this structure, together with the peculiar character and i)arts of the sunnuit, give it a decidedly cystidean aspect ; while it cannot he allied with the crinoidean genera at present known. CUINOCYSTITES CHRYSALIS, N. S. 1M,.\TK XII rt. KKIM. 10, 11. Body small, daviform, unsymmetrical, gradually enlarging from the haae for half its length and then swelling a little more rapidly, and again contracting more abruply towards the sunnuit. The expansion being greater on one side, while the other is nearly straight or a little concave, gives an unsymmetrical form. There are about six ranges of plates ; the lower i-ange being comparatively long, the number unknown; the second range consists of elongate heptagonal plates which, on their upper truncate faces, support in direct series three smaller hexagonal plates, and above the last one there is apparently a small arm-l)cai-ing plate. Between these direct series of plates there is an intermediate or interradial series of three plates alter- nating with the others, the upper ones of which are pointed al)ove, allowing the fourth plate of each of the adjacent radial series to join at their lateral margins, giving but live plates in the range immediately below the summit. The summit is unsymmetrical, showing evidence of two apertures and five slender arms or tenta- cula. Surface of plates striate. Formation and Localif/j.— In limestone of the age of the Niagara group at Racine, Wisconsin. inj:;e in diroot init IS imsyin- iitiiil aportiiro tlio miirj;in is s or tcntaeiila. noidea, would iidial HcvivH of s having this [' the BUiniuit, Hied with tlio from the base dly, and again ^pansion ))eing ^ht or a little )()ut six ranges U', the number )tagonal plates ct series three e is apparently ■series of plates ee plates alter- pointed above, adial series to ^ in the range jnsynimetrical, arms or tenta- Niagara group 10 x.i GENUS KIICALYPTOCIUNUS, C.ii.ii sh. TIds gcmis has usually been descriluMl as having live liasal plates; but I)i-. TitoosT, in his Memoir on the Crinoidea, has desei'ibed the genus as having four liasal or pelvie plates. In the study of the collections IVoni W'aldion, Indiana, in ISOl (12, this featui-e was fully ascertained, thus confirming the original observa- tions of Dr. TitooHT.* The basal plates of the species of this gemis are usually small, and cither concealed in the depression or covered by the column. The ibrni and relations of these plates are shown in fig. 1, which I Id. 1. represciits the ba.sil and lii'st radial plates ol" /uini////ifucr/iiii-s tu'lafun as seen i'rom the in- side, and showing more con- spicuously than on the exte- rior. In the original specimen both these ^^v^_^ r^^' and the lower part of the (irst radial plates /^rC/ are covered by the column. In the dia- gram, fig. 2, the basal plates of IJ. iielatuK are given of the natural size, and in their relation with the first radial plates ; the plates are s* )wn from the exte- rior, the ring indicating the extent of the column. This determination of the ba.sal plates will remove the Genus Euca- LYi'TocKiNUS froui its present position among the Crinoidea which have live basal plates, and bring it into association with Melocrinus. EUCALYPTOCRIXUS CORNUTUS, X. 8. ri.ATL a, KKIS. S, !(, 11). Body (without the arms) .somewhat turbinate, distinctly angular, with the base broadly truncate and more or less concave. Basal plates comparatively large, extending from the centre nearly one half the distance to the edge of the truncation. First radial plates large, forming the circumference of the base, and abruptly bending upwards they extend nearly one-third the height of the calyx ; second radial plates small ; third radials nuich larger than the * 1 Md not at that time publish an account of this structure in my jiii]R'r on tho AViiMron fossils, wisliinjr that it might first appear in the pulilieation of Dr. Tuoost's Memoir; hut .since that Im.s been delayed, I notice it in this place, giving Dr. Tkoost the credit of the original discovery. 20 HiMumtl, snppoitiii;; the lirst .siipranidiiils, whicli uiv of tn(.(U'iatc Hizu. The llrst iiitornuliiil plate is conipunitively large, coiimieniiMj; just above the e(lj,'e of the hasal trmu-ation, and siii.porting two smaller [.lates above. Kavii of the lirst radial plateH, on the part just above the basal truncation, bearn a HtroiiK central spine, with a proniinent rounded ridge on each side, extending to the ui)per lateral nuirgin and joining a similar ridge on the interradial plate, and another ridge extends from the upper side of the central spine, and joins a similar rie in :nown. Arms t has heen dis- f the exterior the form and 4 stronj^ nodes [all. ase deeply and and nearly the are marked by second radial ;ed to a mere first and third d the arms and ;ated above by a )lates separated lie character of teen larger, and me of EuoALYP- } Niagara group EutJAI.YI'TOCIllMKS CUAHSUH, HaII,. I'l.ATi: XI, I'Ids. ■.>, ;i. Eiicnlyplocrinua crai»ua, IIm.i, ; in TransiictioiiM of thy Allmny Institute, IV, p. 1<)7. 1802. Specimens which are eastrt of the interior and impressions o|" (be exterior, present the genenil aspect of this species. It is extremeK variable in form. Sometimes it is ri'gidarly turl»inate and convex on the sides; other specimens are extremely elongate and sometimes abnormal in their development, hiiving the supraradial plates mnted at their lateral margins, and the second interradials with the first axillary plate resting nptm their upper sloping sides, instead of the truncated upper liice of the interradial and third radial plates. Tliis variation sometimes extends only to one or two of the rays, and sometimes, as liir as can be seen, to all tlu- plates of these series. Formation and Locnlit/j.—hx limestone of the Niagara group at Racine, Wisconsin. EuOALYl'TOOIlINUrt OUCO.VFCUB, N. 8. PLATK XI, KKl. 1. Body small, reversed conical; base narrowly rounded or obtusely pointed ; basal plates small and curving upwards. First radial plates com- paratively large ; the second and third smaller. The two supraradial plates join at the lateral margins, and the narrow interbrachial rests upon them, and does not truncate the third radial. First interradial plate large, narrowly truncate above. This species occurring in several specimens is a remarkable form of EucALYPTocRiNUS, being much more slender than any other species of the genus known to me ; and presenting the peculiar relations of the inter- brachial plates, which are elevated to a higher position than they occupy in tlie normal structure of the genus. The position of the interbrachial plates, which appear to be uniform in this species, is sometimes observed in specimens of E. cnmus. Formation and Locality.— In limestone of the Niagara group at Riicine, Wisconsin. .i X ft 22 EuCALYlTOCUIXUa ORNATUS, II ALL. i'l,ATK XI, I'HiS. 1, '). ,: ,„„„„. ".-- -- '•- -»•■ -"■-• "•'""™'" "" ''°"' '■■ "■'■ ''"■ .rui» specios i» couunon .t lUcino und Waukesha. It occurs as c.»ts „,■ the interior l.ut rCaiui.-s the nuu-ks of its structure n, a greate, o, s de le r periection. The impres..„„s of the exterior ,„ the co„. ;m uLtone .re very well marked and characterist.c ol the spec.es. ''1 ;: :1s :/the ^sts ..ve a so.uewhat ohtusely p.utago.. !■„,; with a broad spreading hase, and a constricted upper n,argn, n ^•rcludition they much resend.le in lorn, and i^oporfons the A/,»,fo- ,,,•„,« „dma of the Niagara shale at Waldrou, Indama. EUCALYI'TOCKINUS CiKLATUS, HaLL. // Hat, PalffiontolosyofNewYork,ll,r-21U,Plate47,iig.4. I' t rvi- tliP iiitprior and iiui)ression!< of the exterior Some sueciinens ot casts oi the lutenoi auu u i J" rof a species of Eucalyptocrinus, iron. Waukesha, appear to me iiot to be disthiguishable from the New York species. GENUS CYATHOCRINUS, Miller. CYxVriiocuiNUS pusiLLUS, Hall. Coiuparo i'o/«ri..criH./s pmfonms, KohMKii. LUt suu Plate iv, lig. "• , , Specimens of a small species of CYAxnocRiNns or Poteriocrinu^ resemble bpccunen ,,resentini? characters somewhat mterme- the one described l)y Ivolmi-r, prcsi.uL.nfe ri;.,h. between that species and C. jmsillus. ';;,«;;:: ..„„ il^-I- «n,estone or tl. age of the N,agara group at Racine, Wisconsin. CyATHOCRINUS CORA, N. s. PLATE XI, KIGS. 13, H. Body rotund. Bon,e«hat hroadly turhinate. rounded >«'";.;»f S^''^' I lactLd a little Mow the n.iddle of the ^" -^^ J » ^ ™ swelling out above; having the upper n.arg.ns of the ad.al pUU> inTurved and pronnnent in the n.iddle. There is a smgle small amd I The bsal plates are con.paratively large, r.smg above the r 18C0, p. 20. 1861. [t occurs as casts ! in a greater or irior in the com- of the species, usely pentagonal ppor margin. In rtions the Rhodo- 21U, Plate 47, iig. 4. ,ns oi' the exterior ha, appear to me 200. 18(V2. itliclieu Tennessee, p. 54, RiocBiNUS, resemble ion\ewhat interme- :'the Niagara group below, and gently ubradial plates and of the radial plates is a single small anal ge, rising above the 23 ■< f'. curve of the l)asc to nearlv one-tliird the heiinate, roun.led at the l.se, with the urn. bases pronmu.,^t. Basal plates (?) concealed heneath the column attaclnnent. M.b- nulials lou^-, hepta^onal. First radials ^vider than Ion,', hepta^onal. Second radials nuich smaller than the first, somewhat (puid. angular in .eneral form, but having the upper or lateral angles more or less widelv truncated. Third radials broad and short, nnich sn.vl er than "the second, and supporting on each of the upper slopn^^ sules two or three supraradials ; giving two arms for each ray. Ihe n-st interradial plates are hexagonal or heptagonal , supporting two or t^u^ee smaller plates in the seccmd range, with several smaller phit^s . .vl,ove The arms, as far as known, are two from each ray. 1 he don.e is depressed convex, with a son.ewhat large prol>osc.s on the anal side (the spaces between the aruxs being a little g^atcn- on hat .ide) The surfaces of the plates are marked by node-like ridges nvdiatin.- iVom the centre, and the sutures between the plates are deeply marked and apparently nearly Hat in the bottom. The specimens vary irom three-iburths of an inch to one inch in hei..ht with a diameter of one-half to three-fourths of an mch. Ihey oeJur as casts of the interior, and the characters of the exterior have been derived from the natural mould in the limestone. _ Fonnolion an, /..%.-In limestone of the age of the Niagara group ;xt Waukesha, Wisconsin. Rhodocrinus'? rectus, n. s.* I'hATH XI. FIG. 10. Boav sul.cyli„a,lcal, rounde-l below; l.a«.l plates ,.f .nodiun, size; those '„ the second .^ge „u,eh large,, and suppovting thvee ot .f plates i„ dhect superposition, the last one or ibnrth plate o, the ser.es -nsU,ining two small arm plates. The intermediate range consists of four plates in direct succession, the last one narrowed above and i„ ,l„. ..kl«U«, 1«E0 :>'■!. «' ^»»»; u „o,«.s*., liv. l»«.l l.l.a^,. .hid, ,,n. sl,.>«„ « l.o „( tl,» .1».'« 1 "'"'■*" J" ^';;„,'„,l,,..,li,,l.. »,ul s„piK,„ing t,v„ i,.U.n,.l»l lJ.t=», ises proniiiient^ uchment. Sub- mg, heptjij:on;il. ivt <[uad. -angular jles more or less D, uuu'h smaller [)er sloping sides L ray. The lirst •ting two or three il smaller plates each ray. The proboscis on the e gi niter on that node-like ridges en the plates are jttom. to one inch in ' an inch. They he exterior have he Niagara gronp ;icdium size ; those three other plates )late of the series iate range consists ir rowed above and es ? rectus, ami corrcctcrl liniitions of the stnu-ture s, which arc shown to he ig two internulial i)hites, ec radial plates. w.> lying between the arm-bearing plates. The position ol" the aperture has not })ecn determined. The specimen described has a length of one inch and a diameter of (ive-eighths of an inch. Fonnation (Oid J^ncnUhj, — In the Racine limestone of the Niagara group at Racine, Wisconsin. Among the collections from which the preceding species have been described, there are some other obscure oi" inqjcrfect fragments which appiirently beU)ng to eystidean forms, but they are not in a condition to be designated. These localities in Wisconsin have proved more prolific in species of this family of fossils than any others known to mc, and some of the forms are more remarkable than any heretofore described from rocks of this age. In nearly every locality where these cystideans occur, the Car/joninus oruitltts has been found. The specimeiis, however, are for the most part small or of medium size, and usually more elongated than the same species in the Niagara group of New York ov in Teimessee. GENUS GLYPTASTER, Hall. Glyi'taster ocuidkxtalis. Hall. PLATE X, I'Ki. :i. Glyplnster occidentals, IIaij, ; u\ Transactions of the Albany Institute, TV, p. 204. 1SG2. The original specimens of this species were derived from the Niagara shales and shaly limestones at Waldron, Indiana. Among the collections from Racine, are some casts which are undistinguishable from those of Waldron, and I have thus referred them. There are, however, some casts of a less rotund form, which is appa- rently a distinct specie.s. Glyftastkr i'p:xtangulauis, x. s. I'LATK X, KKi. 1. Body reversed pyramidal, pentangular, regularly expanding to the bases of the arms. Basal plates five, small; subradial plates short, show- in"- the commencement of ridges which unite on the first radial plates. First and second radials marked by a central longitudinal ridge, which divides on the third radial plate, as in other species of the genus. Interradial spaces quite flat. G. W'. 4 Tliis species is nmch more slender in form than G. occidenfa/k. In its casts which is the usual ctmdition of the specimens, the smaller indi- viduals resemble the Sfcpkamrhms amjulatus, with which it corresponds in size and proportions. The larger specimens have a length of an inch and a half, with a diameter of one inch at the summit. Fonmdim and localWj.— In limestone of the Niagara group at Raoine, Wisconsin. GENUS ACTINOCRINUS, iMillku. ACTIXOOHIXUS (SaOOOCIU.VUS) wniTFIELDI. ^^Lr^^H•^■/^^s mnrcmmmis, AV. .t M.; in Mem. Hos. Soc. N. II., 1, p. 87, IMiite ii, fig. 5. injelix, W. \- M. ; in Mom. Hos. Soc. N. II., 1, p. llt», I'latf ii, li;;. 7. Jcli,H>c.ri,WH christyt, II am. ; in Transactions of the Alb.iny Institute IV. 1S(12. Not Jdinocrinns chrislyi, Siiumaiu.. del. Rep. oC Mussoun, p. l'.»l, 1 1. A, tig. i. 18o,>. This fine species resembles the Adinocrmus {Saccocnnm) speciosus, ll.M.L {Pal. N. Y., II, p. 205, PI. 4(5, lig. 1); dillering however in the size and propt)rtions of the plates, and the more prominent ridges upon the plates of the radial series ; but principally dillering in having a second bifurcation of the ray before the arms become free. This species from Waldron soinetimes attains a length of nearly three inches, and having a diameter at the sunmiit ol" one inch and a half. Some specimens of casts from Wisconsin have the form and arrangement „f parts corresponding with the Waldron specimens. Most of these are small, scarcely exceeding an inch in height, but a single specimen from Waukesha is nearly three inches in length ; and a fragment of another irom Uacine indicates an individual of still larger dimensions. The casts of the smaller specimens have the arm — bases more prominent than is usual in the Indiana specimens. Fomation and Locality .—Th^ original specimens are from a calcareous shale of the Niagara group at Waldron, Indiana. It occurs in limestone of the Niagara group at Racine and Waukesha, Wisconsin. ACTINOCBINUS (SaCCOCIUNUS) SKMIIIADIATUS, N. 8. I'l.ATK X, FIG. 1. Body elongate, urn-shaped, slightly constricted near the top of the first radial plates, the sides above Ijeing sub-parallel; base obtusely rounded. Basal plates rather large, forming about one-fifth the height of the calyx. First radial plates very large, nearly equalling half the entire height of the calyx, nmch higher than wide ; second r 27 3,-/ 'dcntidk. Ill its le smaller inJi- 1 it corresponds iiy;th of ail inch ;roup at Raoine, , I'liitu ii, iij:. 5. !itu ii, lig. 7. ,'. 1S()2. M.A, lig. 3. 1855. 'i'linus) speciosus, however in the iient ridges upon I having a second I of nearly three inch and a half, and arrangement Most of these are le ispecimen from ;;ment of another linionsions. The 'e prominent than from a calcareous x'urs in limestone isin. N. 8. lie top of the lirst al ; base obtusely )out one-fifth the e, nearly equalling than wide ; second radials small, elongate, hexagonal ; third radial; smaller t'lan t!ic second, wider than high, and variable in form, being laostly licpta- gonal, supporting on tiieir upper sloping faces supraradials, tlif niim))er and extent of which are unkiu)wn. First interradial plates large, hexagonal, succeeded by two vertical ranges of smaller [)()ly- gonal plates. Anal area unknown. The spe(!imen from which the above description is taken is an internal cast, imperfect cm one side, so that the entire charac^tcrs are not seen ; but the large size of the first radial plates, and the constriction of the sides above the middle of these plates, is very remarkable. From the characters on the cast it would appear that the plates were marked by rather strong radiating ridges, which rising from a point above the centres of the first radials, pass to the interradial plates above, while the lirst radials are smooth below, and in their upper part are marked b}' sharp rounded ridges, rising from the same point as the oblique ridges, extend- ing upwards and bifurcating with the divisions of the ray as far as pre- served in the specimen. This feature of narrow rounded ridges, following the divisions of the rays, is approached in some specimens of Succocriimn christiji = A. (aS'.) ivhil- Jielili ; but the oblique ridges have not been observed, while the entire calyx is much less expanded than in that species. Formation and Localitij. — In limestones of the age of the Niagara group, at Ilacine, Wisconsin. GENUS MACROSTYLOCRINUS,* Hall. CYTOCIlINUS,t EoEMKH. Macuostylocuinus striatus. Hall. I'LATK X, FIGS. 7, S. MacrosUilocrinus striatus. Hall; in Transactions Albany Institute, IV, p. 207. 18G2. The originals of this species are from Waldron, Indiana. A cast of a species of this genus from Racine is similar in form and proportions, and is probably identical with those from Waldron. * Pal^7, I'lalf u, I.-. 4. lbG5. '/'((W»nM)tTi?ii7M «t'r//(ui i, TiioosT, MS. xNot y/ctinocrunis v,'neuilianu», Siu maiu.. (ieol. Hq.. "•" Mis.-^'X'n, p. 193, 1 late A, lig. 1. Body turbinate, sti'ongly lobed at the arm-lmses. Basal plates (bur ; suc- ceeded by live radial series of three plates each, and subdividing upon the last one. Interradial series composed oi' one, two and three plates in the successive ranges. Anal area scarcely dilVering irom the other interradial spaces. This species has the structure of Meloorinus, and though dilfering in form from the typical species of the genus, I see no sulUcient reason for separating it at the present time. Foi-mation and Localiti/.— In limestone of the age of the Niagara group at Racine, Wisconsin. Dr. Troost's specimens are from Decatur county, Tennessee. GENUS GLYPTOCllINUS,* Hall. GlYFTOCRINUS NOB1LI8, HaLL. PL.VTK X, KKiS. 1», II). aiyptocrinus iwbilis, IIall- Hep. Progress Geol. Survey Wisconsin lor 18G0, p. 21. 18G1. Body large, robust ; from base to the first bifurcation of the ray sub-hemi- spherical ; arm-])ases above this point prominent, giving a strongly lobed form; dome highly elevated, the dist^ince from the base of the free arms to the base of the prol)oscis being once and a half as great as the distance below. Proboscis strong, subcentral, entire length unknown. Basal plates of moderate size, spreading almost horizon- »Ina paper upon some Niag.ir.a fossils from Indiana, published in the Transactions of the Albany Institute in 18G0, I made some observations upon the tienera Glyi'TOCKINUS, Glyptas- TKU Balanochinus and Lamptehocuinus. At that tin.e I had overlooked the fact, that the .enc'ric name Balaxocu.xus had been proposed by I'rof. Agass.z, h. 1840, m Jiulkhn Soc. des Scimcen Nuturelks, A'euchattl ; and therefore the same name proposed by Dr. Ikoost n. Ins Catalogue of 184'J, for a very diilerent fossil, cannot be sustained. In IStJO, Dr. Febdinaxu KuKMi. 11 proposed the name Lamptkuocuinus in Die Silurhche Fauna des Uesthchm renucssee, for the same fossil to which Dr. Thoost had given the name Balaxocuixus, and this later generic designation will necessarily be adopted. ,. , .. „ It nviy however, on the linal revision of the crinoidcan genera, become a (piestion, whether those forms now distinguished as Glvptocrixls, Glyptastkk and Lamptekocuinus should not con- stitute a single genus. 20 ;(). is-io. •liitu ii, tig. 4. 18G5. ., I'late A, lig. 1. plates (bur ; .suc- uid subdividing e, two and three y differing I'rom jugli dill'ering in icient reason for le Niagara group Decatur county, tally from tiie ccjlunni. First radial plates large, second radials hexagonal, nnicb wider than high; third radials broadly [lentangular, siip[)orting on each upper sloping side a sei'ies of four su[)raradials ; the upper one of which is a bifurcating plate, and supi)orts on the upper oblong sloping edges a series of arm plates; giving eight anus to each ray, so far as determined. First interradial plate large, six or seven sided, with two smaller [)lates in the second range, three in the third, and several small polygonal plates above, (lUing the interbrachial spaces and ccnmecting with the dome plates. Anal series unknown. Doui" near the base, conqxwed of small [udygonal plates, gradually increasing in size towards the proboscis; the dome is strongly lobed, and the depressions correspond with the inter- brachial spaces, Surface of calyx plates marked by a single set of strong radiating ridges, which connect at the sutures with those of the adjoining plates ; the interspaces occupied by one or more small round nodes, which are sometimes confluent. The ridge along the radial series is nnich the strongest, and ibrms a node on the centre of each plate, Tlie dome plates are marked hy similar, but less distinct lines, and a small round node on the cei re of each plate. ' I860, p. 21. 1801. he ray sub-hemi- giving a strongly m the base of the id a half as great ral, entire length ii' almost horizon- le Transactions of the Yl'TOOKlNUS, GLYPTAS- okeil the fstct, that the :0, in Bulletin Soc. des i by Dr. Tkoost in his 1800, Dr. Fekpinand i If'estlichen Tennessee, ;s, and this later generic question, whether those L'uiNLS should not con- This species differs from (J, decadactijlm {Pakeontolotjn JVeiv Fork, Vol. i, p. 281, Plates Ixxvii and Ixxviii) in the larger size; the shortness of the base; the very large dome, and strong proboscis; as well as in the surface marking and greater number of arms. Geological Formation and Localitij. — In limestone of the age of the Niagara group, Racine, Wisconsin. Glyitocrinus au.mosus (McChesnhy). I'LATK X, KKJ. H. G'lyptocrinus siphonatiis, Hall. Rep. Progress Geol. Survey Wiscoii.sin for 1800, p. 22. 1801. G. sijiliunaliis, 20tli Report St. Cab., first edition ; roctilied in description of plates. EucahjplocTinus armosus, McChksnkv. New I'aht'ozoic Fossils, etc., p. Do. Feb., ISOl. Body large, broadly obovate, the greatest width being above the origin of the arms; calyx narrow below, spreading gradually to the bases of the arms; dome inflated on the anterior (?) side. Arms rising from the body in pairs with deep constrictions between ; arrangement and forms of plates of calyx not fully determined ; those of the dome are small and polygonal. Tlie above description is drawn IVoni internal casts. This snecies dilVers from d. mUlis in the nn.ch greater length of calyx which is not contraete,rcss (ieol. Survey Wisconsin for 1800, p. 22. ISGl. Body below the arms subturbinate, with sides somewhat inllated in the lower part ; arm-bases prominent, leaving deep interl)rachial spaces ; dome low, strongly inllated on the anal side, surmounted by a slender subcentral proboscis. Basal plates small, pentagonal. Subradial plates proportionally large, hexagonal. First radials heptiigonal, a little larger than the subradials; the firm of the second and third radials undetermined; the second are as large as the subradials; the third very small. Interradial plates, six ; the lirst hexagonal, as large as the second radials, with two in the second range, and three in the third range, miiting with the dome plates. Anal plates numerous ; form and arrangement unknown. The above description hai^ been drawn from the internal casts of several specimens, which exhibit the divisicm of the plates. This species differs from B. sculptus, Tuoost; Lampterocnnus tenncsseen- m.Uomm {SUurian Fauna of Western Tennessee), in being more distinctly turbinate or obconical; in the deeper interbrachial spaces ; the iutlation of the dome on the anal side ; and in its uniformly smaller size. 31 ts. This suecu's lyx which is not t)r()iid iind spread- he ciists there is mit of the dome idly, as if "t had perture w of the Niagara Kli. I for 1800, p. 22. ISGl. lat inllated in the terbrachial spaces ; lunted by a slender ijional. Su))radial lials heptiigonal, a ! second and third as the subradials ; lirst hexagonal, as id range, and three iites. Anal plates e internal casts of plates. lerocrinus tenncsseen- ing more distinctly jaces ; the iutlation nailer size. BRACHIOPODA. OKNUS OBOLl'S, Kk ii\vam>. Compare T1U.MKHI:I,I,A, Hiimmis. Oholuh conu.vdi, n. a. rt.ATK XIII, I-'ICS. I, i; IM.ATK XXV, KMiS. I, J, .1. Siiell depressed orbicular or subdiscoid ; width usually greater than the length, gibbous in the middle and conqiressed towards the margins. Dorsal valve more convex than the ventral. Surface unknown. The rostral porticm of the valves is extremely thit^kened, lor nuiscular attachments ; and this area extends in an (elevated plate or transverse septum which becomes free at its anterior margin, except where it is supported in the middle by a vertical septum. The iutei-ior sur- liice (jf this plate, towards the antero-lateral margins, is marked on each side by a rhomboidal muscular scar, varying somewhat in the two valves, and in dilferent individuals. On each side and just without the up[)er or posterior lateral margins of this plate, there is a depressed oval or reniform nuiscular scar, varying in character and area in the two valves. In the dorsal valve, and probably in the ventral valve also, there is an ehmgate ovate imprint, extending Ironi a narrow point, at what may be i-egarded as the extremities of the hinge line, close to the cardino-lateral margins, and gradually expanding below, reaching nearly half way to the anterior margin of the shell. This transverse plate in the ventral valve sometimes shows muscular markings just below the rostral area as well as anteriorly. The cast of the rostral cavity is small and neatly defined, witli marks similar to those of dented lamellaj (?) along the car- dinal slopes. The cast of the dorsal valve shows the impression of a broad, shallow, spoon-shaped plate, with the median septum extending nearly to the base of the shell. The figures on Plate xiii are given from casts of the dorsal and ventral valve. The impressions from these are given on Plate xxv of this edition of the Report. Some ten years since, having these fossils under consideration, I pro- posed a new generic name for them ; but sending drawings to Mr. Davidson, he gave me the opinion of himself and Mr. Woouvvard that 3.6 82 tliey 1h«1()ii<;i'(1 to the Genus Oholith. There are certaiii pcii'ts cf dilVer- eiice, however, which I have heen inelined to helieve are of j^euerie importanee, and I an. not entirely s.tislie.l in referrin- them to that uenus, as ilhistrated, thonjih (dosely uUied to it. In the mean time, Mr. Hh.mncs has pnhlished a(ienus TuiMi:ui;i.i,\, ilhistratin^' it hy a specimen Irom the (Jiielpli hmestone. Now the lossils nnder c(msi(U'ration, in the earUer stages of j^nnvth, have the transverse phite hut partially attached at the sides; and the processes shown in Mr. lJiLLiN<;s' figures are sometimes slightly simulated l»y the casts »)f the spaces on each side of the median septum, which extend hetween this transverse plate and the exterior shell. There are, however, no evidences of tlnee longitudinal septa. The exterior of the shell is unknown, lait prohahly is essentially >mooth, or with only lines of growth. From the liu't that in numerous specimens collected from these rocks there is no shell preserved, I infer that it was calcareous and not phosphatic as in l.iN(iri,.v and Disiina, which usually preserve the shell in all the dolomitic limestones. Formi> m,/ Loctdiff/.— In the Leclaire liinestonci, upper part of the Niagara group, at Leclaire, Iowa, and in limestone of the same age at liacine, Wisconsin. GENUS STTU)PTI()I)ONTA, H.vll. STiiornonoNTA i-uoKiiNitA, Hall. PLATE XIM, I'KiS ,!, 1. /.„>la;m pn,f,,nda, IIau.. Pahv....tok.>ry N. Y., II, i-. (U. I'lut. xxi, il.irs. 4, 5. 1S,V2. Si'ophovuva niufrarcns^s, W. & M. ; m M-.n. l!..st,. So.. Nat. Ili.st., I, ,.. '.I-J, I'bUe n, l.«. '.I. iSC Shell large, the full grown individuals having a width ol more than two inches, with a length exceeding one inch and a half; deeply con- cavo-convex; the extremities sometimes angular or extended, but more often in the casts obtuse or rounded. Surface of young shells somewhat regularly marked by strong elevated strias, with four, five or more liner striae l)etween. In older shells the stria? become more irregularly fasciculate, and the stronger ones rise in unequal ridges upon the surface. This feature is, in greater or les.s degree, impressed upon the casts of the interior, which, combined with strong vascular markings, gives a distinguishing character to speci- mens in that condition. The hinge line is crenulate, with a broad tbramcn ; the muscular impression of the ventral valve is ovate or Habelliform, and extends for two-iifths the length of the shell. 33 •; :j poii'ts (if dilVor- » lire of j:;oiH'rio m tlii'm t(» that mis TUIMKHKI.LA, Now tlie lossils /e the tnuisverse ses shown in Mr. the casts of the nd hetween this ver, no evidences il\ is essentially :hat in nnnierons preserved, I infer •I, A and DisciNA, lestones. upper part of the the same age at . 4, 5. lHr)2. •J, IMiile ii, tig. '.I. iSGiJ. of more than two half; deeply Con- or extended, bnt ce of yonng shells striae, with four, the stria3 become es rise in unetpial ter or less degree, b, combined with Ljharacter to speci- date, with a broad I valve is ovate or ifftli of the shell. IMiere is a central longitudinal callosity extending from IIk' apex HometimcH for one-third of thf length of the muscular impression. The Sfriti>lii)iiinin iiini/iirnisis of Winciiki.i, <^' Maimy (loc. cit.), aj)pears to me to Ite identical with this. The specimens in my possession, tiniii western localities, show a consldi'ialilc \ai'iety of form and propoi linns, and yet preserving the essential character of the species. A sj)ecimen connnunicated by l*rof. \\ inciikm, nndi'r tlie nam<' .V. nt(U/(iirii,sis, has the divaricator scars [)ro[)«)rtionally a little more elongate than usual, but the same feature is preservi'd in nthei- specimens. The specimen figure 3 is of a yomig or nu'diiun si/e, presciving a j»art of the exterior surliice of the ventral valvi' on the lower mari-in, whiU' the other portion is the impression of the extt'rior of the dorsal valve. Fig. 4 is the cast of the interior of the ventral valve. Fonii(i/i»ii mill Lonilitij. — In limestone of the Niagara age, at liacine, Wisconsin; lJridgei)oit, Illinois, and Waldron, Indiana. GEM'8 SPIIJIKKKA. Sl'MMl-KliA KIIIOHA, JJAl.l,. I'l.ATK .Mil, FKiS. .-,, 7. Spirifer eudora, IIai.i.. Utp. l'io);iv,s.s (icnl. Survey Wisconsin lor iSOd, j,. ;2.'). IHGl. S. eiidiira, IIai.i,. 'I'liinsaciioiis of tlu' AIIkmiv Insliliili', 1 V, |.. -JI I. i,S(iJ. Shell of moderate size, transversely subovate, length and width as three to four, valves extremely gibbous; hinge-line less than the width of the shell below ; cardinal extremities rounded ; aiva moderatelv liioh • Ibramen triangular, a little higher than wide ; marked by three to lour simple, .strong, angular plications on each side of the mesial fohl and sinus. Dorsal valve regularly arcuate ; beak .somewhat incurved ; mesial Ibid of moderate width, llattened above and slightly depressed in the h)wer part. Ventral valve most i)rominent near the umbo; beak strongly incurved over the area ; mesial sinus broad and deep. The minute surface markings, as shown in specimens IVom Waldron, Indiana, are line nidiating striiD, prec.-isely like those of ,S'. manoplfum of the Lower Ilelderl)erg group of New York. The specimen.s from \\'is- consin ai'e all casts of the interior. This species licars some resemblance to S. mdrioplciim, but it is pro- portionally more gibboi.s, the fioiit more rounded, the area higher, and the plications not directed so oblicjuely outwards from the beak. G. w. 5 34 rnnmilinn „w/ l.»nilH;i. - In linu'st.)i»e of the aj^f of the Nia«;ini Krouj), lliciiit', Wisconsin, iind also in lockHof tho winiu agi' at Waldron, Imliami. (Una Si'lllll KIIA (WllltOS.V, II.M.I.. I'l.ATi: XIII, !• HIS. ,), M. Spirifer gibbosus, Mm,... \Uv. I'm^ciTss (Ifol. Survey Wisconsin i\.r Iscn, p. -5. iMll. SIr'11 suiniiwhat below the nicdinm si/.(',;^il>l.oiis ; beaks sli^ditly im-urved, area loss than tlie widtb of the shell below, about three tiiiu-s an wide as hi-h ; cardinal extremities nunuKMl ; foramen lar^c, hi-her tjiiui wide; valves marked by about four simi)le low rounded plica- tions on each side of the mesial elevatiim. Dorsal valve extremely gibbous on the ui-.bo, rej^ularly arcuate transversely ; mesial eleva- tion broad, tlattened above; plications not extendinj,^ to the beak. Ventral valve deeper than the dorsal, but less arc ite ; mesial dei)ression broad and deep, rounded at lH)ttom. Surtiice of l)otli valves (in well preserved specimens) show evidence of line radiatin-^- stria'. This species resend)les S. alsjnis of the Niagara group in Mow York, but is nuich larger, fre(iuently more than twice as wide as that species; the mesial elevation is wider and not so high. The specimens described are all internal casts, so that the external smla(;e characters cannot be fully given. Fomation and Uca/ih/.— In limestone of the age of the Niagara group, llacine, Wisconsin. i Sl'UUl'KKA I'LICATKI.LA, Var. IIADIATA, SoW. ri.ATK Xlll, l'l(iS. !)-ll; I'l.ATK XXV, PUIS. 1-li. Suir!fan pln-utdla, var. radUUa, Sou., Pdtliyrh lineatus (text), radiulus (index) : Sow. Min. ('on V I) 4'i;5 li"S. 1, 12. iS'iv. \wl Jnuinia lincdtim, Sl\\iri>i. Spiriler nuliatus^ a' \H:V , Sow. SUu.ian Sysl.u., I'lut. xii li;: <>. mO._ S,„rilW rndtatus, yWnx. Synopsis of th. Siluoan loss.ls ot Ire an. I, p. o< . 1848. Snirlf^r rlicaUUus, Sa..tk>. ; in Mon.oirs (loot. Survey of (..yat Hnlan., II, p ..-8 1848. Spirher a,rl,ena, l»Avn.soN ; i.. Hul. Soe. (leol. .le Fra,u:e, 2a senes N p ^24. .1848. JpiAfer radialus, Ham.. I'al. X. V., IF, PP. -U), 205, 'late xxn, 1., J ; Plate l.v. 1 ,. 0. 8o2. SiunlWjdicatclln., var. radiaU.s, Saltku. Siln.ia, Plate -x, ..,. 12; l«la e xxu, !.,.<. 8 J. Sphyen, pru-.aeUu, I.i.N..sTU..M ; in I'roc. Itoyul Aea.l. ul Science ol htoclii|), Idi'ou, liuliaitii. lid, p. 'Jl. iMil. jjjlitly incurved, throe times us 'II liiij^c, hi^liur ' rouiiilt'd plicii- ^alve extremely ' ; mesial elevii- ly; to the lu'ak. ire ite ; iiu'sinl Surface of both L)f line radiating p in New York, as that species ; imens described icters cannot l)e 3 Niagara group, IS (index) : Sow. Miu. .. 37. 184S. II,p. ;i-JS. 1848. , p. 324. .1848. I'lato liv, liv'. 0. 1852. liiU- xxii, iijr. 7. ISo'J. ;klu)liii, p. ;;.')S. IStJU. her synonym for Ljonsin specimens istics. The form jIjous. The car- nn dinid c'xtiernitiosare roimded nnd the aroa more (»r loss distinctly dofnu-d. Some riMUiiins of surliico stiia* are sonu'timcs distingiiishalilo on the cast, an/intff//ii propei' ; such specimens are very gilil)ous, with a high area and broad di'cp sinus in tlu> scutral valve, while they dill'er in form from the simply striated specimens. The peculiarity noticed in the smooth or liiiely striated species is the presence of distinct lamolho in the dorsal valve (as shown in fig. !) of Plate xiii) (liverging from the apex and presenting all the characters of the dental lamelUo of the ventral valve. These marks ui)on the cast are not simi)ly sharp cut depressions, but thi' edges of distinct thin plates, which are joined to the inside of the shell, sometimes for half its length. A siiecimen, fortunately broken, shows the interior of a shell witlu ut tilling, and those dor.sal lamolUiMiro seen extending downwards halfway to the base, and uniting with the shell precisely as the dental lamella' of the ventral valve. These lamelhu are divided near their origin, and "•ive oil* the crura from which the siiires have continued.* Specimens of this character are rhomboidal, gibbons, with distinct mesial sinus i.nd fold; small specimens like the one figured, are more common than larger Hi. 17. Spirifer nohilh, Bauuax,)k. Silurische R.ucl.ii.o.l. Bnlm.on ; in IIah.ix.ku's Xaturuisson .schaCtliche Abl.an.lUmgeu, Hand 2, Tab. xvui, lig:. 2, a, b. ipJfer inconstant, Hall. Ko,k P.-gres.s (icol. Survey W ..scons.n for l..,0, p. 2... 1801 . Shell transversely elliptical, the length a little more than half the width; hinge-line two-thirds as long as the greatest width of the shell; cardinal extremities romided ; both valves moderately con- vex, 'marked by strong angular dichotomizing plications. Dorsal Pen Shei: A ligs. 2s, 2t. ■amidnl ; liri^ht (1 lu-i-jiilit nearly ■ shell ; ventral 3n narrow ; del- iis l)r()a(l, nearly ■somewhat angu- the mesial told eirion ; the inte- dental lanielliB, ;erior snrCace of crowth. and (hie .MAN ; but diilers elevation of the m//iiia, BiLLiN(iS, ig of til hinge- L S. trapc^oiikdis Lch other might area, figured on S". nu/iiita, are of e Niagara group, lloehester, N. Y. iiNCKu's Xaturwissen 18G0, p. 2Ci. 18C)1. e than half the test width of the moderately con- ications. Dorsal 87 valve most prominent on the umbones ; mesial fold l)i'oad and simple on some speeimens, and on others divided into two, three or more plications in front; beak produced and moderately incurved. Neu- tral valve larger than the dorsal; beak very [jrominent, but little incurved ; area high ; deltidium large, height and width nearly ciiual ; sinus l)road and deep, simple or with two or more plications. Entire surliice marked by strong distinct radiating stri;e. The specimens are casts of the interior and exterior. Fro a the figures and descriptions of Baruande (loc. cit.), I am com- pelled to regard this American species as identical with the Bohemian lorm. Not only is the general form and dichotomizing of the plications similar, but the peculiar elevation and attenuation of the beak of the ventral valve represents very precisely the Racine specimens. This species may I)e readily distinguished from others by the strong angular l)ifurcating plications, the numl)er of which vary in different individuals; some being nearly simpio, having but lour or five on each side of the mesial fold, while others have nearlv double that number on the front margin. The ruunber of plications on the mesial told and sinus arc subject to the same variation. Formation and Localiti/. — In limestone of the ngc of the Niagara group, Racine, Wisconsin. GENUS PENTAMEUUS, Sowerhy. Pkntamehus .multicostatus, Hall. IT.ATK Xrrr, KKiS. !.« i!, Jl. Pcntamenis multicaslatus, l\.\i.h. Ivcp. Progres.s Geol. Survey Wisconsin for 18f)9, p. 1. ISfiO. Shell obtusely subcuneate, the valves nearly ecpially convex below the middle, ventricose on the umbones ; sides somewhat straight, and abruptly widening from the beaks ; greatest width in front, nearly equal to the length of the shell. Surface marked ])y luuncrous, even, rounded, little elevated strioe, which are [jreserved on the lower half of the cast. Both valves are often slightly impressed in the centre below the middle. Longitudinal septa of the dorsal valve reaching more than one-thii-d the length from the beak. The spoon- shaped cavity of the ventral valve is narrow and deep, and the septum reaches more than half way to the base of the shell. 38 This species of Pkntamkiujs is usimlly from one inch to an inch and a half in length. It is readily distingnished from other species in the rock bv its narrowness at the beaks, and ))y the nnmerous longitndinal stria; which mark the casts. Foi Illation aiul Lncali I n.—lw limestone of the age of the Niagara group, at Wauwatosa and Waukesha, Wisc(msin. PeNTAMKUUS (PKNTAJIEnKLLA) VKNTIIICOSUS. I'l.ATK XIII, KIGS. 1S-2I. Pei^tamerus veviricosus, IIat.i,. JUt. of Trog. Geol. Survey TMsconsin for ISr.^t, p. 2. 1800. Shell ventricose, subglobose, wider than long; hinge-line extended and al)ruptly rounded at the extremities. Ventral valve nuich the more convex, and broadly sinuate belo^v the middle of the shell ; the sinu- osity sometimes not reaching the beak, but prolonged into a broad lin<»uiform extension in front. The sinus of the ventral valve and the mesial fold of the dorsi»l valve are marked by thi-ee or four obscure, or sometimes conspicuous, rounded plications. The casts are marked by strong concentric lamina; of growth, and some faint, rather broad, radiating stritc: nmscular impression of the ventral valve Itroad, subcordiform, and radiatingly striated. The triangular pit beneath the l)eak small and shallow^, and the median septum short, reaching no more than one-fourth the length along the curve of the valve. Dorsal valve having the septa united at the base of junction with the shell, spreading very slightly above, and reaching nearly half way to the basal margin. This shell presents some variation from the strict characters of Penta- MEiws, and will probably fall under the proposed genus Pentameuella.* Fnnnation and Locality. — In limestone of the age of the Niagara group, at Waukesha, Saukville and elsewhere in Wisconsin, and at Bridgeport 1 Illinois. * See page 193 of this Report. 39 ) ail inch and a !cies in the rock iijtiliforiius of the grey sandstone of the Clinton group. Tliese species are probably not true Ambonychia, but in the condition in which they occur, we have not suiUcient characters remaining, to authorize their separation. Fonnalioii and Localit/i. — In limestone of the age of the Niagara group, near Milwaukee, and at Wauwatosa and Racine, Wisconsin. «■ SJf 40 GEM'S AVICULA, Ki-kin. AVICULA UM'ATA. ./,mVu/« nndnin. Ham,. I'ah.-.utulo.y of New York, II, p. -JS:',, Plat, tix, n^^ "J. A specimen from Kiu-ino, Wisconsin, iind another from Bri.l^erort, Illinois, rescmbk- this species from the Niagara group of New York. AVI'.'ULA KMACKKATA, C()NUA1>. A.icula evuuerala, Conuau; in Jour. Xr.u\. Nat. Sci. IM.ilu.. V!II ,-. Ii41, Plato xii, li^. 15. 11.U.L. (ii'ol. Ri'imit Kourth District N. \., p. HHt. llALL. Pal. N. v., II, pp. 83, 28-2, Plate lix, li-. hi-e. This species occurs at Racine, Wisconsin, and at Bridgeport, Illinois. GENUS PTEIUNEA, Goldiuss. Pteuinea niiiSA, n. s. IM .VTK XIV, I'Ui. 1. Compare Pterinea strirtcosta, McCnESNEY. New Pahro/.oic Fossils. Body of the shell ol)li(raeiy subovate, extremely inequilateral; anterior wing rather long, distinctly sinuate at its jimction witii the body of the^hell, posterior whig short, not extending so far as the posterior extremity of the shell; umbo prominent, rising a little above the hirge-line. Muscular impression large and nearly round, situated near the middle of the length of the shell. In the cast, beneath the be:vk or just anterior to it, there is one short curving dental pit, with a smaller nccessory one separated by a callosity. The surtiice c,f the shell is marked by strong radiating and concentric striiu, which, on the partial decomposition of the shell, present a cancella- ted texture resembling that of a bryozoan. In one specimen measured, the width from the two extremities along the hinge-line is nine-tenths of an inch; and from the umbo to the pos- tero-bas"d margin, in the directicm of the umbcmal slope, it has the san-^ extent; the length vertically from the hinge-line is six-tenths of tin nich. Fomation and LocaUt>j.—A.i Bridgeport, Illinois. 41 n-. 12 )iii Bri(l,!L;erort, New York. 1, I'lato xii, li,i:. 15. geport, Illinois ateral; anterior k^itli the body of as the posterior little above the round, situated be cast, beneath rving dental pit, by. The surtiice L!oncentric striae, esent a cancella- xtremities along Lunl)0 to the pos- :, it has the sarr'i ;enths of an inch. GENUS CYPKICAKDINIA, Hall. Phouahi.v -SEDCaVlCKlA, M'Coy. Oyi'iucahdim.v arata, n. s. ri.ATi; xiv, I'Ui. (I. Shell subovate, varying from moderately to extivmely gibbous; body of the shell subovate, alate posteriorly; beaks near the anterioi' end, which is short and rounded. Surliice marked by strong eoncentriv liimellose ridges. The species resend)les in form the Alodiohpsis (^Vijpvlcarilinia) vrnhdoa- liiata ol" the Niagiira shale of New York; but the eoi- 'entric ridges are stronger, and the line undulating stria' are not visible in any of the western specimens. Fonnatlon and Locroadly subovate, moderately convex, becon\ing somewhat gibbous on the mnbo; beak about cme-fifth distant from the anterior extremity ; gradually expanding posteriorly so that half way between the beak and the posterior margin it is once and a half as wide as in the line just anterior to the benk. The straight hinge extends about half the length of the shell, and the cardinal margin is thence 6 42 Le MODIOLOPSIS RECTITS, \. S. IM.ATK XIV, I'lliS. I, :,. Shell clom^ute, nr.rrow, moaeratoly convex, Leaks sal .anterior ; hinge- line long- and straight; the greatest width ol' the shell is at the posterior end of the cardinal line, narrowed eiinally above and below towards the posterior extremity. The anterior niusenlar impressions large and strongly detined. The casts show that there hasl.een one strong sul.triangnlar tooth beneath the beak ol the right valve, with one or two smaller ones, with corresponding pits, in'the opposite valves. The lateral teeth are very slender. The surl-ace has been marked by concentric stria>, and a tew strong undu- lations which are preserved in the casts. The length is abont one inch with the greatest breadth hall' an inch. This species resembles Modlolopsis {TelUnomija) machwnifomk of the Clinton group of New York, irom which it dillers in having the beaks more nearly anterior and in being lesH narrowed posteriorly ; whde the greatest width is at the posterior extremity ^' the hinge-hne, nistead of at the beaks. Some specimens, which are scarcely specilically distinct trom those described, have proportionally a somewhat greater width, but ni other respects are identical. Foymation and Localtl^.-ln hmestone of the Niagara group, at Wau- kesha and llacine, Wisconsin, and at Bridgeport, Illinois. MODIOLOI'SIS SU15ALATUS, HaLL. Modiolopsls subulalu., Hall. Palaeontology x\. Y., 11, PP- 84, 285, I'lalos xxvii, lix. Some specimens from Racine, Wisconsin, and Bridgeport, Illinois, are apparently identical with this species of the Niagara group of New York. The specimens are casts and more or less crushed and imperfect. GENUS AMPIIIC(ELIA, n. o. The Acephala present great diiliculties in the way of satisfactory- generic reference ; and it is often scarcely possible to arrive at certainty with regard to their true relations. A single species from Wisconsin, which is somewhat numerous in individuals, has the general exterior aspect of the more elevated forms Th( The c iterlor; liiu^o- rior muscular low that there 10 beak of the espondiu^' i)its, slender. The w strong uudu- th is about t>ne u-a/ormis ol' the ving the 1)eaks jrly; while the •line, instead of inct from those li, but in other group, at Wau- 'lates xxvii, lix. )ort, Illinois, are up of New York, nperfeet. Y of satisfactory- •rive at certainty liat numerous in e elevated forms 1 43 of LiM'TonoMUS of McCoy; but it cauuot nevertheles.- l>e referred i)ro- perly to that genus. The lieneral form of the shell is subrhomboidal, with elevated beaks. The casts present evidence of a large tiiangular cartilage pit ])eneath the beaks; and just anterior to this, and separated by a Hiiu i)r<)(ess ou each valve, is an ai)parent second pit. No teeth have been discovered on the extension of the hinge-line. The nuiscular impressions ai'e faint iuid the shell thin. It is possible that there may have been a cartilage pit and adjacent tooth, as in Mactra and Amimudism \ — a leature whicii cannot be satis- factorily determined except from an examination of better specimens than we possess. There is a llattened external ligamental area not unlike that of the Arcacea. AmIMIIC(ELIA lkidyi, n. s. 1M,\TK XIV, FKiS. 1;(, II, 1.",. j/inbimijchia iwi^lfcta (.'), McCiiKsxi-.v. New I'alii'/.oic l'os>il.s, p. 88. 18(')1. j/miiliicwlia iieiilirla (r) McCiiksnky. Trans. V\\W!vj.o Acad. Sci., I,i>. 41, 'Mate ix, tijr. 'l. \X>n . Shell ecpiivalve, ine([uilateral, somewhat rhomiioidal, gibbous exce[)t upon the expanded posterior side ; height and width subequal ; umboncs gibbous ; beaks much elevated and incurved, pointed, fall- inu; from one-fourth to one-third the width within the anterior margin, which declines from the hinge-line at a very obtuse angle ; hinge-line equaling somewhat more than half the width of the shell. The casts show a large triangular pit beneath the beak, and sometimes there is evidence of a thin dividing septum. There are no visible lateral teeth. The surface of the casts is usually smooth, or showing only a few strong lines of growt' . In a single specimen preserving a portion of the shell, the surface is marked by line close radiating stria3. The height of the shell from beak to l)ase measures in dillerent speci- mens from two to two and a quarter inches, with a width almost precisely corresponding. The depth of the two valves is about one inch and (ive- eighths. Some smaller specimens, whicli niiiy l)e of this species, have a length and ))readth of half these measurements. Owing to pressure and other causes, the species exhibits great variation in form and proportions. Amcmg the specimens are two with less elevated and more approximate beaks, and less gibbous form, with a <\ r 44 .rreater extension in In.nt and greater width behind ; which may prove j^pecilically distinct. Fonuation and Uc/ih/. In the limestone at lltieine and Wanwatosa, Wisconsin, and at B.idgeport and another locality* (unknown) in Illinois. UENUS CYPllICArvDITES, Conuad. Cvi'UlCAlUtlTKS (!) QUADUILATKIIA, N. S. IM.ATK XIV, I'lOS. H, !l, 10. Shell somewhat quadrilateral, the angulated umbonal slope dividing the valve into nearly equal areas. Valves inllated, height and dei.th nearly e(iual ; beaks closely incurved and sharply angulated ; the angulation gradually becoming obtuse, and continuing along the um- bonal slope to the postero-basal margin. A cast of the right valve shows a conspicuous muscular prominence just anterior to the beak, with two strong lateral Iblds marking the cardinal line ; the entire surface is marked by low concentric undulations. On each side and parallel with the umbonal slope there is an extremely narrow groove and fold, indicating radiating lines upon the surface of the shell. Just posterior to the beak there conunences a distinct groove, with a slight ridge on the lower side, which continues about half way betw^een the hinge-lino and the umbonal angulation, but not parallel " with either, and extending to the posterior margin of the shell. This species is angulated like many of the extreme forms of Myalixa ; but the strong muscular marking, with lateral hinge-teeth, prohibit its reference to that genus. Fonmtion and Localitij.-ln limestone of the Niagara group, at Bridge- port, Illinois. ^ . Among the collections obtained from Wisconsin, there is a single shell which is not referable to any established genus, though well preserved in its general form and external characters. Although it would be very desirable to know more of its structure before giving a generic name, I shall nevertheless propose a designation. Its general form indicates that it belongs to the Cardiacea, and this is confirmed by all that can be learned of its structure. * Two spechnens ^vere received several years since from Prof. C. U. Shepa.u., >vhich were creilited to Illinois, but the record of the particular locality had been lost. 46 ■//• ich may prove lid Wiuiwiiiosii, nvn) in Illinois. >po dividing the ight and depth iingulated ; the <•• iilon};- the uni- the right valve nor to the beak, line ; the entire )n each side and y narrow groove ice of the shell, let groove, with about half way , but not parallel of the shell. rnis of Myalixa ; ieth, prohibit its ^roup, at Bridge- e is a single shell h well preserved it would be very , generic name, I )rm indicates that ' all that can be SiiEPAKi), which were GENUS PAL.EOCAllDIA, n. g. Pai„kocai{di.v cordhfohmi.-^, n. h. I'LATK XIV, KKiS. U, IJ. Shell cordiform ; valves ()])rKpiely subovate, ventricose ; umbones gibbous, with the beaks prominent, attenuate and incurved; hinge-line very short, extending a little in advance of the beaks, and showing the margins separated. The anterior end gradually rounding into the basal margin. In the partial cast the posterior slope shows a ridge on each side rising just behind the beak, and in a line slightly divergent from the cardinal margin, reaching about half way to the posterior extremity, where it becomes obsolete. The surface is marked l)y fine close radiating striie. This species has the general aspect of some of the more gibbous forms of Amhonychia, but the short hinge-line separates it from that genus, while the extreme prominence of the umbones and incurvation of the beaks give it the aspect of a true CAuniUM. The specimen was given to me by Dr. Day of Wauwatosa, who informed me that it was I'ound in a quarry a little east of that village. Formation and Localitij.—ln limestone of the Niagara group, near Wauwatosa, Wisconsin ; in beds which are probably a little below those of Racine and Waukesha. T n" 46 GASTEEOPODA. The lullowing species have l>eeu identilied with known Ibniis, or deter- mined a.s new : GENUS PLATYCERAS, Coxhap. Platyckiiah niacahknsis, IIai-l. yfcroailia niagarcims, IIai.l. Palrcontolopy, N. Y., II, p. '2HX, Plate (;0, (ifr. ?,. IWiiHi/ioii aiol Loadih/.—ln the limestones of Racine and Waukesha, Wisconsin. GENUS PLATYOSTOMA, Conrad. PlATYOSTOMA NIACiAUKXSIS, IIaLL. PlalyoKlomn iiia^rarennis, Hail. Palivontolo):y, N. Y., II, p. 12S7, Plalu W, li-. I. Formation and LocalWj.—ln the hmestones of Racine and Waukesha, "Wisconsin. GENUS STRAPAROLLUS, xMontfout. Strapauoli.us mopsus, n. s. l'I,.\TK XV, KIGS. '.Jl, -'-'• Shell discoid; whorls four or more, cylindrical, very gradually enlarging, the outer one sometimes a little llattened on the upper side for a part of its extent; suture line strongly marked; umbilicus very wide, and showing all the volutions. Spire depressed, rising little al)Ove the surface of the outer volution. The proportion of height and width is aliout as one to three. The individuals measure from half an inch to seven-eighths of an inch in diameter. A specimen having the latter measurement is three-tenths of an inch in height. Some fragments of outer volutions indicate specimens of larger size. Specimens of this species, when compared with the figures of >S'. (Upline, Billings, have a very similar aspect on the lower side ; but the eleva- tion of the spire, as given in the description, is much too great for our species. Fnnmdinu and Lncality.—lxv limestone of the Niagara group, at Racine and Waukesha, Wisconsin. Ti IbniiH, or dotoi ■ ntc CO, Up. ?,. ami Waukci^lia, MiiU'Od, fi-. 1. I and Waukesha, dually enlarging, upper jside lor a ; umbilicus very ssed, rising little portion of height liils measure Irom ter. A specimen m inch in height, ens of larger size. ^ures of aS'. daphne, e ; but the eleva- too great for our 1, group, at llacine 47 >•' GEM'S CYCI.ONKMA, 1 1 all. (Jyci.onkma ( i;li:\ ata, n. h. I'l.Ali; \V, I Ki. I. Shell conical; spire elevated, gradually Uqiering, embracing an angh' ol' about fortv-live degrees. Volutions rounded, ventricose, about five ; gradually enlarging to the aperture, which has been nearly circular. The cast from whiidi the species is descril)ed, possesses evidence of revolving sti-i;e, without indications of a central band. Height nine-tenths of an inch ; width six-tenths of an inch. Fonudtion (tnd Lwidllji. — In liaiestone of the Niagara group, at llacine, Wisconsin. GENUS HOLOi'KA, Uau.. IIOLOI'KA HAI{.\I()NIA ? BlI.LINtiH. Hulopea harmonia, HiLLiNiiS. Nuvv spccius of Siluriuu Fossils, p. 15s, lij,'. 142. ISC.G. There are several specimens in the collection, so nearly corresponding with the figure given by Mr. Billings, that 1 nmst regard them as the same species. In a specimen of the same size as the iigure cited, the middle of the last volution is subcarinate and Ihutened above. The spire is a little more elevated than the figure, and the hist volution a little more ventricose l)elow. It may prove to be a distinct species. Another specimen of similar form does not possess the flattened band, while the lower side of the last volution is llattened. Formation and Localilii. — In limestone of the Niagara group, at Racine, Wisconsin. HOLOrEA GUELPHKXSIS, BiLLIXUri. PLATE XV, FIG. 18. Ilo'.opea giidpbenBis, Billings. New species of Silurian FossiLs, p. 159, fig. 143. 1862. Several fragments of a species, differing from any other in the collce- tion, resemble the Canadian species; but being all quite imperfect, no full comparisons can be made. Formation and Localitij. — In limestone of the Niagara group, at Racine, Wisconsin. o-i 48 GKNl'S IM.KUUOTOMAHIA, Dk Kuan. k. PLKimOTOMAUlA (K'CIKKNH, N. H. ri.Aii; XV. i-itis. 11, !-•; I'l.ATi; XXV, riiis.il, m. PhuroUmmria lahnmi, var. occideni. Twt'iiticth Uej). N. Y. St. Cub., Ist e.lit., \>. :'.»:'-. IHCT. Shell somewhat rlioiiihoidiil-ovate ; 8i>iiv iiKuU'mtely clovated; vohitions uhout three, the hiHt one mpidly exiiiimliiiK, siihiuij^Mihir, and niaiked hy 11 spiral hand a little ahove the niidcUe; upper side somewhat llattened; lower side rounded, and in the last one heeomin^' ventri- cose. Suriiue marked hy strong revolving and transverse striic. An examination of other specimens of this sjiecies proves it to he dis- tinct IVom tlie r. labnm to which 1 had heretolWre referred it as a variety. ( I Plkuhotomahia uai.ki, IIai.i,. I'l.ATK XV, KKiS. 1.), U. Pleiirolomaria halei, IIai.i.. Ucport ol' J'rogicss (icol. Survey Wisconsin for 18G0, p. .'!4. 18C1 . Shell sul)orl)icular, the spire moderately ascending, the height eiiual to a little more than two-thirds the greatest diameter, consisting of tiiree or four volutions which are rounded on the top, and expanding somewhat rapidly in nize ; the last one quite ventricose, and hi the cast is suhangular on the periphery; the under side of the last volu- tion is rounded from the edge into the rather large umhilicus. The surface, as preserved in a mould of the exteiioi- in the stone, is marked on the upper side of the volution l>y ten or twelve mode- rately strong revolving ridges, which are smaller and more closely ai-ranged towards the suture, where there is a slightly depressed or llattened space. These are crossed hy numerous less strong, closely arranged transverse striae, which ))end hackwards from the suture, and have a strong retral curve on the narrow concave hand of the periphery. Surface characters of under side undetermined. This species is so entirely distinct in its form and surface characters from any other species yet known in our Silurian rocks, that it can he readily distinguished. It is more nearly allied with forms such as P. htcina of the Upper Helderhcrg and Hamilton groups of New York. Formation and Loealif>/.— In limestone of the age of the Niagara group at llacine, Wisconsin and Bridgeport, Illinois. 49 .''/ .< lit., p. :u:i. iHt;7. itod; volutions 111', iind iiiMi'Ucd ^ii(ie soinewliat ^coining ventri- svei'se Hti'ia'. vu.s it ti) l>e ilis- l it as 11 variety. r 18G0, p. .^4. 18G1. eight i'(|ual to u [isisting of tliree and expanding Ljose, and in the of the last volu- mubilieus. The in the stone, is ir twelve niode- nd more elosely tly depressed or •is strong, closely from the suture, ;oncave band of [idetermined. u'face characters :s, that it can be )rius such as P. New York, le Niagara group Pl,i;UIU)TO.M.VUI.\ ('ritOCIKtXKM \) HuYI, II.M.I-. I'l.ATK .W, Kill. Ill; I'l.ATK XXV, I H.-*. II, \i. I'leiiriilumariu hoyi, IIm.i.. IIi'IikiI of rnij^rosM (Icol. Survt'y Wwcoiwiu for iMIiO, p. ;t5. I Mil. Shell broadly dcpre.Hsed-conii-al, the spire modcrntely elevated, consisting of about four volutions whit'h are gradually enlarged from the apex, the last becoming slightly ventricose towards the iii)erture. Volutions tlattened ui>on tlu' iii)pt'r side, and the entire lu'ight of each one showing above the other; [)eriphery .somewhat llatti'iied, with a depressed band truncating the upper angle. Lower side of xolutions tlattened, excejit the outer hall" of the last one, which is I'ounded towards the aperture, and al)ru[)tly de.<IA, N'. s. l'l,ATK XV, ri(iH. 15, 1(1. PlnirnUmiaria idia, IIai.l. Hejiort of Progress Geol. Sur^-ey Wisconsin for 18(')0, p. 35. iMil. Shell depressed orbicular, moderately convex above, and broadly umbili- cate beneath, with four volutions which are moderately convex above, and gradually increase in size from the apex, the outer half of the last one being more ventricose and regularly rounded on the periphery, and curving into the broad uml)ilicus; aperture, or sec- tion of volution near it, broadly ovate. Surfiice characters unknown. This s[)ecies difl'ers from the last in being less elevated, in its more gradually increasing volutions, broader umbilicus and absence of angu- larity on the periphery. Fdinidtlon ami Lucalitij. — In limestone of the age of the Niagara group, at Racine, Wisconsin. G. W. WtitA 50 r« Pleuuotomaria AXIOX, X. s. I'l.ATK XV, mi. 17. Shell subconical, volutions about lour, the apicial one minute, the first three volutions small, rounded and gradually expanding, while the last one becon«es extremely ventricose and evenly rounded ; suture line deepb impressed and more than half of the preceding volution exposed above it. The aperti-re has been subcircular and very large. Surface marked by strong revolving striae, which are crossed by concentric strite of less strength, giving a cancellated structure. The middle of the volution is marked by a rather wide and little elevated band, upon which the stri« have a slight retral curve. The surface ( aarsicters are very similar to those of P. lucina of the Lower Helderberg and Hamilton groups of New York ; but the shell is more elevated and attenuate towards the apex, and the suture is more deeply marked. Its form is intermediate between the species just cited and F. Uneata* The species described is from a gutta percha cast and an impression in limestone. Formation an. LocalUy. — In limestone of the age of the Niagara group, at Bridgeport, Illin-is. GENUS TROCHONEMA, Salter. Trochoxelia (Eunema) FATUA, N. 8. plate xv, figs. 7, 8. Spire elevated; shell turritiform, consisting of about four or five volu- tions, which gradually increase to the last one which is moderately ventricose; volutions biangular, leaving a flattened space upon the back about equal to the flattened space between the upper angle and the suture line; lower side of the last volution rounded; aperture ovate-elongate. The specimens are casts of the interior, and in this condition are readily distinguished from any other species of similar form in these rocks. • See Fifhtnth Report m the State Cabinet of JVat. Hist., p. 165, Plate v. 51 imte, the first ing, while the unded; suture eding volution md very large. ;re crossed by ited structure, vide and little trai curve. f'. luchia of the jut the shell is suture is more ecies just cited I an impression Niagara group, A gutta percha cast shows the surface to be finely striated ; the flat- tened space on the back of the volution is margined on each side by a slender carina, and the strioe between are apparently coarser than those above or below. The height of the specimens varies from less than one inch, to one iii'-h and seven-eighths. The transverse diameter of the last volution is aboui one inch. This species has a more elevated spire than T. umUUmta of the Tren- ton limestone, and, so far as can be determined, has had no umbilicus. Formation and Locality. — In limestone of the Niagara group, at Racine and Greenfield, Wisconsin. TliOCliONEMA (CyCLONEMA \) I'AUl'EH, IIaLL. I'l.ATK XV, I'MCiS. ->, I), It; I'l-ATK XX.V, KKi. i:i. Plcurotomaria pauper, Hall ; in Twentieth Report X. Y. State Cabinet, 1st edit., \). ''A'.\. iSCiT. Shell small, obtusely conical, the apicial angle from seventy to eighty degrees. Volutions three, four or more, rapidly increasing in size from the apex, rounded tibove and on the sides, a little flattened on the top below the suture line, the last one subangular below ; suture distinct, not channelled. Aperture rounded or slightly elongated, and scarcely sul)angular above on the inner side. Uml)ilical cavity rather large, marked by three or four revolving bands. Surface strongly striated ; the upper part of each volution marked by five or six revolving cariniform strioe above the stronger carina upon the angle of the outer volution. These are crossed by fine lines of growth, which are not always preserved in the fossil. ur or five volu- h is moderately space upon the upper angle and unded; aperture is condition are r form in these Owing to the thickness of the shell, the internal casts do not often preserve more than three or four l)ands indicating the exterior strios, and the apicial angle is usually less than that of the exterior shell. This species has been identified by Prof. Winchell as Pleurotomaria hulei ; and two specimens communicated by him under this name, are in all respects identical with the species described by me under the name Pleurotomaria paujier^ from which genus it must be separated on account of the exterior character of the shell which has since been discovered. Formation and Localitij. — In limestone of the age of the Niagara group, at Racine, Wisconsin, and Bridgeport, Illinois. 165, Plate v. if a 52 GENUS MUUCIIISONIA, Pihlui-b. MUKCmSONMA CONH.VDl, N. S. IM.A TK XV, 1-lli. 111. Shell turreteJ, somewhat rapidly ascending, consisting of about seven volutions which are distinctly carinated on the nuddle or scarcely above the middle. Above the carina the surlace is slightly concave, and below the carina very slightly rounded ; while the lower side of the last volution is regularly rounded and s.nnewhat ventrico-.e. The surliice has been linely striated with irregular undulations, cor- ren)omling with the lines of growth where the stria) have beco.ne crowded The entire length of shell to the base of the last volut.on .s one inch and nine-tenths, and the diameter near the base nine-tenths ot an inch. , ,• . j This species is descril)ed from an imprension ni the limestone and a . -utta percha cast from the same. It is a well marked species ; dillering from every other in these rocks in the sharply carinate volutions and elevated spire. In some characters it is allied to M. xantippe, Billings, but the spire is more elevated : the length of that one, from the carina of the last volution to the apex of the figure, is the same as the length from the same point to the carina of the second volution above, in our specimen ; while the diameters of the lower volutions in the two are about equal. Formation and Locality. -In limestone of the age of the Niagara group, at Kacine, Wisconsin. MURCHISONIA LAPHAMI, HaLL. 1 LATK XV, l-'l(i. '.ii'. Marchisoma laphami, IIai.l. Rei-ort of Prog. Geol. Survey Wisconsin for 18G0, p. 30. 18f.l. Shell turritiform, robust; volutions seven or eight, gradually increasing from the apex, rather ventricose on the exterior, with close sutures ; the upper half of the volutions very slightly flattened ; giving a perceptible angularity in the region of the revolving band. Section of volution iH-oadly ovate, the breadth equal to four-fifths of the height, and the greatest diameter on the lower third. Suriiice marked near the middle of the volution by a somewhat broad band, I r of about seven liddle or scarcely slij^htly concave, e the lower side ewhat ventricos, LOXONKMA LHDA, X. 8. 1M,.\TK XV, KKi. l'. Loxon.na — sp., lUu. ; in Twentieth Report of N. Y. State Cub., 1st edit., p. S4G. 18G7. Shell turretod. Spire rapidly ascending, composed of eight or more volutions, which are moderately convex on their surfaces, a little more abruptly rounded below the middle, and very gradually increasing in diamci- ; suture close, not vovy distinctly marked , apicial angle about twenty degrees; colunu lar side of aperture elongated or pointed. Other characters of aperture unknown. Surface characters ol)scure ; faint indications of transverse ridges crossing the larger volutions exist in the matrix. This species was originally compared by me (loc. cit.) with L.Jitchi, to which its imperfect cast bears some resemblance ; but a critical examina- tion shows it to be a very distinct species. The species referred by Prot. WiNCiiELL to L. mhulata is apparently identical with L. hla, judging Irom a cast of the upper volutions communicated by hiin. It is, at any rate, very distinct from L. subtdata, the spire being much less rapidly ascending. Fomation and Locality. -In limestone of the age of the Niagara group, at Wauwatosa, Wisconsin, and Bridgeport, Illinois. GENUS SUBULITES, Conrad. SUBULITES VENT1110OSU8, HaLL. PLATE XV, FIG. 1. SuMii... ventricosa, iUu. Paleontology of New York, II, P-^47 PL 83, fi«^7. Subulites brevis, W. & M. ; in Mem. Bos. Soc. Nat. H.s., I, p. 100, PI. n, fig. 19. 1865. This species occurs at Wauwatosa ; received from Dr. H. Day ; and also at Bridgeport, Illinois. < GENUS BUCANIA, Hall. BuCANIA ANGU8TATA, HaLL. Bncania angusMa, Hall. Palaeontology of New York. II, p. 349, PI. 84, fig. G. A specimen undistinguishable from the species occurring at Gait, Canada West, has been found at Kacine, in Wisconsin. 55 edit., p. 34G. 1807. eight or more surfaces, a little very gradually binctly marked , lide of aperture rture unknown, ransverse ridges with L. Jitchi, to critical e^amina- rel'erred hy Prof. t.v/«, judging from [t is, at any rate, apidly ascending, le Niagara group, >1. 83, fig. 7. Among the collections from Wauwatosa, Waukesha, Racine and other localities of the Niagara group, in Wisconsin, there are remains of other species of GASTKUoroDA than those here described; but their con- dition is such that, for the most, their description or illustration would add little to our positive knowledge of the subject. The doscriptiim of the interior casts of species of this class of fossils is usually even less satisfactory than that of other fossils in a similar condition ; but as it seems unlikely that we shall get them in any other form, we are coiai)elled to make such use of them as will aid in further comparisons of the fossils of these rocks from other localities. ii, fig. 19. 1865. Dr. H. Day ; and '1. 84, fig. f). occurring at Gait, .ii id 5G CEPHALOPODA. GENUS NAUTILUS, Buhyn. Nautilus occidentalts, Hall. SauMu. iLiinUcs) ocddentulis, Hall. Geolo;,.cal Uei-ort ol \N ..coumu, p. 441. Shell very largo, .ubdi.coidal. Volutions two or more, rapidly expand- in- contiguous, the outer portion of the last volution bcconnng tree and extending in a nearly straight line, while the earlier portions are compressed on the ventral side by the dorsum of the preceding volution; septa distant; section elliptical; siphuncle small, sub- central. Surface marked by regular equal liUet-like stria3 or ridges, ^vhichare curved backwards on the dorsum ; and in more perfect individuals, these are cancellated by liner longitudinal or revolving striae. Specimens sometimes measure twelve inches in the greatest diameter of the disc. . ,yp,. This fossil was published by me, under the name occulentahs, m 180U. The name pijanteum, given by M'Cii.sney, being preoccupied, the name cu^ceUakau was given a year later by that author. It appeal, to me t mt these forms are not true LrruiTES, and that they should be referred to the Genus Nautilus; therefore since there is already a Kautllus ffii/anteus, the name occidoitalis has precedence of cancellatus. Formation ami Zoc.^.-In limestone of the age of the Niagara group, near Milwaukee, Wisconsin, and at Joliet, Illinois. Nautilus capax. Hall. UUntes capa., Hall. Keport of Progress GcoL Survey Wisconsin for 1859, p. 3. 1800. This species differs from N. occUcnlalis in its more rotund form, the section of the outer volution being very broadly elliptical or nearly cir- cular, and showing rapid expansion towards the aperture. The materials possessed by me are fragmentary, but sufhcient to leave uo doul,t of specific distinction between it and the preceding species. % 57 Fonnaflou ami Lnro /if //.—In liniostcne of the age of the Niii<;iini j^ronp, iit Waukesha and Kacine, Wisconsin. I also have seen some large frag- ments of the same species in the collection ..f I'n.f. M.vu.Y from Bridge- port, Illinois. 67. Jan., 1800. 9, p. 31. Feb., ISGO. JO. 1801. I, p. 441. 180'J. rapidly expand- )n becoming free earlier portions of the preceding ncle small, sub- l; stria3 or ridges, in more perfect inal or revolving greatest diameter ndentulis, in 18GU. ;cupied, the name ppear.s to me that be referred to the Nautilus (/i(/unieus, he Niagara group, ar 1859, p. 3. 1800. 3 rotund form, the tical or nearly cir- ure. t sullicient to leave 3ceding species. GENUS TllOCllOCERAS, BAUUANni:, II.u.i.. TUOCHOCEKAH DESl'LAISENHK, M'ChESNEY. ri.ATK XVI, KKiS. \ 1>, 10. Trochoceras ,hs,Mnons!s, M'Chksnkv. Now Palu-./oic Fossils, p. OS, l>late viii, li;;. 1. 180(1. Shell dextral, trochiform, making a little mc.re than two volutions, the apex rising to about the .same plane with the top of the adjacent volution, gradually expanding, and the other chand)er continued in a more nearly direct line. Section of the volutions essentially circular; siplumcle small, central. The three outei- septa measure on the dorsum seven-eighths of an inch. Surface marked by strong obliiiue angular ridges, which are curved backward on the dorsum, gradually increasing in distance, and finally there is a considerable space below the aperture, marked only by lines of growth. The intervals ])etween the annulations are regularly concave. I have identilied this form with T. despkinense, WC] having before me a cast of the specimen described and ligured by that author, in which about two volutions can be distinguished. The original of the cast had apparently been a little llattened f'om pressure ; and I have a .speiiimen, not ligured, presenting a similar aspect. Another specimen, having its natural proportions preserved, is more rotund. It does not appear that there have ever been much more than two volutions in the full grown shell, and the section is essentially circular, though the lateral diameter may be a little greater when the dorso-ventral diameter is measured to the bottom of the depression between the annulations, ))ut not otherwise. The dift'erences indicated in the distiince of the septa do not seem to be important. This species l)ears considerable resemblance to Trochoceras troclioiifes of Bauuaxde, Plate xxix, ligs. 16-21. Formation and Localit//.— In limestone of the age of the Niagara group, Racine, Wisconsin. G. W. •/"< 58 TUOCHOOKUAH COSTATUM, ILvLL. IM.ATK XXV, KI(i. 1'). Trockurn;,s cosM II...... Kq""l l''-^-- < '-'"g- S"''^'^-^" "'" ^^■'^•^°"'^'" ^"'' ^"''''' ^""• Shell .Iq.ivsscl trochllbrni, sinistral, oreate.st diauictor about two an.l a ,l,unt.n- inches ; spire depressed convex ; volutions alumt one and a half to two,* gradually expanding h-oni the apex; section snh- cin-nlar; umbilicus broad and shallow. Siphuncle undeternnned. Surlace marked by stn.ng sharply elevated annulations, which in.M-ease in distance and regularity with the growth oC the shell, gradually diminishing on the last volution and beconnng more or less obsolete, or appearing as gentle undclined elevations towards the aperture. Near the apex of the shell there are about twelve of thes,> annulations in the space of half an inch, and on the outer volution, opposite the same point, there are barely six ni the same space. This species is a little less in si/e than the T. .ksplalncm ; the annula- tions are more nmnerous and more sharply elevated, not increasmg m si/e on the outer volution beyond the point opposite the apex ol the .hell Taking a single volution trom near the apex, there are nearly twice as many annulati.ms as in the species cited. The sinistral dn-eetmn of the volutions is, however, a conspicuously dis.inguishmg feature.? The species was originally described from imperfect material, and t.ie figure given is from a gutta-percha cast in a well preserved impression ot°the exterior of the lower or umbilical side of the shell. This species may be compared with T. imlchrum of Bauuande, Plate xvii li<^s 8-lG, but is more finely costate. Fomation ami LocalU,l.-ln limestone of the age of the Niagara group, at llacine and near Milwaukee, Wisconsin. *()ri"-iimlly stated as three or four by mistake. „„*>,„ ..nn^r i;i,lp t sh^e it so,netinK.s hai.,.en.s that the Trochuccras desplainense is qu.t. iiat upon the upper .s, le . tlv t th i Ir Ition are a l.tllc depressed helow the outer one, it might perhaps be suspec ed s Perhaps U.e lirst An^erican speries of this character that ),as been recogn .ed, but M. B.u ^vM,riS;=iyd scribes the twl Ibrn.s, and has .igured several species w.th sm.stral sp. . same in T. snntlbvrgen:' 69 •v .•• y II r.ir isnri, isci. out two and a out one and a ; section snb- undeterniined. latit»ns, which 1 of tlic shi'll, nn'wv^ more or iitions towards i1)0ut twelve of I on the outer ^ix in the same w ; the aunula- t increasing in he apex of the lere are nearly listral direction ng feature.t laterial, and the ■ved impression .1. 3AURANDE, Plate ! Niagara group, it upon the upper side, t perhaps be suspecteci ure, is an exaggerated ed. This, however, is heir natural relations, uognized, but M. Rui- i with sinistral spires, the sjnre or of a siii.dc et of symmetry. The pecies, but the dextral n individuals, and the Tl!0(Iincr,lt.\S .NOTl'M, N. S. I'l.A'ri'. XVI, i-iiis. I, '.'. The entire shell unknown; a fragment of the outer volution shows it to have heeu strongly annuliitcd, with the anmdations heuding ItiwU- wiird on the dorsal side. The trausversc diauieter is greater tliiiu the dorso-ventral diameter, and the direction of the volutions has been dextral. The siphuncle is suhcentral iiud small. It is distinguished from T. msfaliiin hy the dorso-ventral compressicm of the volutions, and hy the dextral direction of the spii-e. The volu- tions have been in contact, and their num!)er, though unknown, is pn.l.a- bly about two. It dillers from T. (/c,sj>laiiiense in the dorso-ventral couipression of the volutions, and less conspicuous ami more ch),sely arranged annulations. Funnnlmi and Lncalltj.—ln liuiestone of the age of the Niagara group, at Bridgeport, Illinois. TuocnocEUAS (Gi-uocKiiAs) ii.\NMSTi:ui, WiNcn. AND Mar. IM.ATK, XXV, KUi. IT. ai,roceras Imnnisteri, Winoikm. and Maiuy ; in Mem. IJost. .Soc. ..f Nat. lli.^t., 1, i.. Kl-J. Shell consisting of about one and a half volutions, which increase in si/e somewhat rapidly: spire gently ascending; umbilicus broad and comparatively deep, the hiteral diameter of the volutions being greater than the dorso-ventral diameter. Surface marked by U)W subangid'.ir annulations, which, turning gently backwards on the sides of the shell, are more abruptly bent into a shallow sinus on the dorsum. These annulations apparently become obsolete towards the aperture ; on the other parts of the shell, there are about six or seven in a space etiual to the dorso-ventral diameter. This species dillers from either of the species described, in its more rapid enlargement from the apex, and in the liner anrmlations. These observations are made upon a cast in gutta-percha, sent to me by Prof. WiNCUKLL, under the name of Gpvceras hanimteri The cast has the appearance of a very pretty species of Trochoceuah, of more delicate proportions than those described in this paper. Formation and Lomlity.—ln limestone of the age of the Niagara group, at Bridgeport, Illinois. .'v ()0 GENUS LlTl'lTKS, Bhkvx. LiTUlTES MAlWnil, X. S. 1'1,ATK XVI, KUiH. (1, 7. SlK.ll of nu.clium ni/e, consistinj^ of three or n.ore dosely enrolled volu- tions, which increase in si/e very gradually from the apex : section ,i,,ular or sul.circular ; slightly llattenc.l on the dorsum, and n,arkelique ridges, which in the outer part of the shell are a little more distant than the septa, while on the inner volutions they are nearer to each other, the increase in the distance of the annulations bein.^ a little more rapid than that of the septa. Owing to the retral curvhvr of the annulations, and the advancing curvature of the septa, the ricrges are cut by the latter near the dorso-lateral angle of the volu- tion, throughout the greater part of the extent of the shell The specimen preserves a little more than two volutions, and we have no portion of the chamber of habitation. Inferring from the prevailing characters of similar forms of this genus, there has probably been nearly or quite another volution at the apex, which is not preserved. Fomation and LoealitiJ.-ln limestone of the Niagara group, at Kan- kakee, Illinois. A fra ventricc ing fro 11 than t\ betweei tral ape The 1 three-fc is two I arcuate the out dianiet( margin The lar vas( In fij a view 01 (• enrolled volu- i) apex : nection nn,iin(l iiiiuked with reguliirly DU the ventral 'OS8 the sides of a point opposite I- greatest eleva- lat abrupt retral apta moderately tubers regularly 1. The space of are equal to the »rsal margins of ral curvature on ;entral. Surface dender volutions, of the shell are a olutions they are f the annulations ini: to the retral ure of the septa, mgle of the volu- the shell. The and we have no m the prevailing bably been nearly 'served, ra group, at Kan- GENTS rilKACJMOCEHAS, liuoi.i.itii". PitHAUMOCKllAH NKHTOU, \. S. A Iragment preserving the outer ciiamber and several of the septa, i< viMitrieose, l)roadly expanded in the dorso-ventral direction, iind niciism- ing from the extreme limits of the apertures, wWwh are luiirginal, more than two and a half inches ; the length of the narrow constriction ))etween them being one inc^li and a (piarter. lioth the dorsal and ven- tral apertures are marginal and expanded. The length of the outer chamber along the middle is an inch and three-fourths, and the dorso-venti-al diameter in the middle of the length is two and a ([uarter inches. The septate portion has been abruptly arcuate, the length of the part remaining being four times as great on the outer as on the inner side of the curve. The greater and lesser diameters of the septa are about as seven to ten. The siphun(de is sul)- marginal. The cast of the outer chamber is marked by what appears to be regu- lar vascular impressions extending outwards from the first septum. In fig. 3 a lateral view is given of the specimen described, and in fig. 4, a view of the aperture. Fl(i. .!, Fki. 4. This species differs from the P. /lerfor, Bilunos, of the Guelph lime- stone of Canada, in being more narrowly elliptical in section, and much more expanded in the dorso-ventral direction at the aperture, as well a,-< «2 '■"T;:i:i:"!::ri,o. p,„...wi,„/. - '^' »" Wiitosa, WirtCDUsin. GENUS CYUTOCEUAS, Golwiuss. CyHTOCKUAS lAIClLLUM, N- »■ I'l.ATKXVIII, ll'i. ■• Shell a,™,ae. „.,U,„lb .xpanding .ow.,-,1. the upertu,., »»ti"'-^';i;^;_ ,,.1 „ littU. narn.wer .m the inn.,- xulu ol the cur.u , ^.pU u, .de ,,,t:.ly convex, vlosely un-anged; siphunolu .nmll, .ul.uuuyn.l nn ,1,0 outer »iclc of the uvch. SudLce n.arked 1>J- regular, e,i„al, „ea ly aelined amudation., «hicl, have a slight retral areh o„ ho extuua e.rve. i„diea.h,g a .nadar sinuo.it, in the ,aarg,n o, the aperture. The an„ulati,>n» are eh,»ely arranged ; on the entailer parts ol the .hell, they are in the proportion of twenty in the space ol an n,ch ; ,vhll on the inner side of the enrve they are nun. approxnnate „,„, „n the outer side n.ure distant. On the larger part o the shell the annulations .nnnher live or six in the space oeeup.ed l,y seven in the smaller parts. Fonnathn u„,l ta,,%.-In lin.estone of the Niagara group near Wan- Nvatosa, Wisconsin. GYHTOt'KltAri FOSTERI, HaLL. This species is known to n>e only in the Niagara lin.estone near Gnicago. Shell sn ing Fonm at Racii CyUTOCEIIAB DAIIDANU8, HaLL. PLATK XVII, KIOS. 3, 4, 5. Tin. species was originally described Iron, lrug,nents, which n, all the ° ^jl^^.j. „„perlect speci- snpc mens seen can he rcacmy laenuueu. 'I which have conre under my notice since the pui ,cat,„n ot the .hell n, ginal description, have induced me to suppose that the loss.l u.ay . ab, :Z^ n,ore properly to the Genus Gvuoe.a.s. The speces occurs at str, Waukesha and Wauwatosa, Wisconsin. IBI^*« In- intcnueiliate IK I I', itiruuluiit, groiil), at \\ iiu- e, section uUii>ti- rve; tsopta uinde- , Miliniiirj^iuiil on iliir, f(iU!il,uoiitly h on the exterior II of the aperture, aller parts of the si)ace of an inch ; iiore aj)proxiniate, r part of tlie shell occupied by seven 11 group near Wau- for 1860, p. 43. 1801. !.stone near Chicago. in for 1800, p. 43. 1801. its, which in all the her imperfect speci- 3 publication of the that the fossil may he species occurs at r.3 CyIIT«)(I;H.VS MIIKVICOUNK, .N. R. n.AiK will, I'His. >,!i; iM,\ri; x.w, rm. ii. Shell small, gently curving and very rapidly ex[)anding from the ai>ex, till' diameter of the outer chamber nearly equaling one hall' « cn-cnlar ^'>l>'-"»;^»' :L one-sixth the transverse diameter of the sh^dl mod,, d ^ concave their n>argin» directed slightly upwards on .he lat.ra ;:::^1 the shelUiving a broad shallow sinus on t.^^^^^^^^^^ ventral sides. Siphuncle sn.all, situated near the do. sal ma.gm C of the Ju .narked oy obscure longitudinal r,dges d,s,a„ frl Ih other from a sixteenth to a tenth of an ,nch ,n d.flere t M idnals and on difte,.ent part, of the shell. The unpress, ns Tf those ridges are distinctly seen on well-preserved casts of the interior. This species is readily distinguished fro.n the others of the genus . TTtb it bv the sli-ht curvature and the greater transverse associated with it, oy int, hHj," inre-er di.meter- the relative dia.neters of the specnnens hgured, .n .ts la.ger p "r e .Ig as lour to live. The relative dlsta,.ce of the septa ...ay v., !:^:wW in diiferent individuals, judgi.rg from other spec.men belore ZZ not ...ate,.ially affecting characteristic features of the spec e. T,,; outer two septa, ne.t the cha.nber of habitat.o.,, are often crowded "*t:„lX"::: W%.-In Ihuestone of the age of the Niagara group, at Racine, Wisconsin. CyRTOCERAS RIGIDUM, HaLL. PLATE XVI, FIGS. 3, 4, n. =;hell s,nall consisting of about one volntion, gradually expanding to a d '1 of thr;e-fou,.ths of an inch with a height of two .nches. sla unk..ow,. ; outer ehan.ber deep. Siphuncle apparently orsal. Surfi.ce of cast n,arked by strong obliquely transver.se annulat,o,s thich beco,„e gradually st.-onger from the concave s.de, a.«i arc Illy curved baekwa,-d on the .niddle of the dorsum. Spaces b tween the annulations eo..cave. without any ev.dence of .nte. ...ediate suraller ridges. E..terior s,.rfi.ce unknown, the spec,..,e„ being a cast of the interior. 05 ..■ d<} ned appearance, the last septum, lere it is nearly oval, and a little tion of the shell, •. Septti distant ihell, niod-jratel}' •A on the lati^ral on the dorsal and le dorsal margin, lal ridges, distant v inch in diflerent The impressions srved casts of the liers of the genus greater transverse rured, in its larger the septa may vary er specimen before u^es of the species. , are often crowded the Niagara group. i lally expanding to a eight of two inches, i ile apparently dorsal. \ ansverse annulations j mcave side, and are y the dorsum. Spaces |] ly evidence of inter- Is vnown, the specimen | The fi<>-ures referred to are the dorsal and lateral views of a fragment. with a transverse secticm. The accompanying outline, lig. 5, shows the form of the entire cast of the interior, as nearly as can be given with the materials in my possession. This specieS; in the external markings of the cast, is quite similar to Trochoccnis nohtm, and not very imlike T. costahuii ; but the enrollment of the shell in the same plane is a distinguishing feature. Formation and Localitij. — In limestone of the age of the Niagara group, at Bridgeport, Illinois. Cyrtoceras heuculks, Winch, and Mau. ri.AT?': XVII, I'lus. Y''' the he irst septun,, and is continued in a narrow constr.ct.on nearly to the apex, where it is united with the larger aperture; the margin of this is con- tracted into tuhular lolds, so narrow as to present the appearance of three small rounded lateral apertures, with —— - a similar one on the dorsal side. This peculiarity of the aperture is suilicient for specific determn>at.on, when compared with any species known to me. fTs. C is a lateral view of the outer cha.nber, and fig. 7 represents the ''7:!I?r;":;«.-In Hmestone of the Niagara group, at Wau- watosa, Wisconsin. Dr. H. Day. GoMPnOCERAS SCRINIUM, N. 8. PLATE XVIir, FIGS. 1, 2, 3. « \t A«rv • in I^Iemoirs Boston Society Nat. Hist., Vol. I, p. 100, Go«.p^ocera8 r,.arc!/ber and first septum .s of Werii^e, transversely suheircular, with a very shght angu.ar.ty on Klfi. li. heinji pori G7 , // t it presents an Nia<>;ara group, ,r If^fiO, p. 42. 18GI. US Oncoceras, of me in this t'ornia- I'-Ui. the ventral side. Outer chamber rapidly contraetinj,^ from near the last septum to the aperture, giving it a somewhat conieal Ibrm, the length heing less than the transverse diameter ol' the septum. Aperture trilohed, the ventral opening small ; dorsal opening moderately large and suhtriangular; the proportitms of the transverse and axial diameters are iis three^to four. Septa moderately deep, with a veiy regular convexity. Siphuncle situated at (me-third the distiince from the ventral margin to the centre. Surliiee marked only l)y irregular lines of growth. Fomation and LocaUtj.—ln limestone of the Niagara group, at Bridge- 1' the first septum, cal section. The j from the apex to j ition nearly to the \ ific determination, Ig. 7 represents the ara group, at Wau- ;y Nat. Hist., Vol.!, p. 100, Dort, lUinoit d first septum, is of \ slight angularity on ^ GENUS 0RT1I0CP]UAS, Bheyx. OiraiOUKKAS ANNULATUM, SoWKIllJY. ri.ATE XX, I'-lCiS. 1, 5, (i; I'l-ATK XXIV, FKIS. 2, :i, I. Orihonras annulaUun, Sou kui.v. Mineral Com'i.ology, W, p. 77, Tah. ^^>^^f ^^]^- mlZaiites un>lulatu., 11,s....k. Anteckn. V, Tab. iv, ii,.(i. Vet. Akad. lla„ai.n,ar, lab. Or^/IccrSite uMUus, lhsiN..iKU. Lethea Suecicu, p 2S Tab. x, %. 2. 1827. Ortln,cerasanaulatum,yUium,os. Silurian sysleu. ami S.luna. Orthoceras undalafun, Hal,.. I'al. New York II, p. 29,',, 'late.s Ix.v xv Ortkoceras nodocosHm, M'Ci.k.xkv. New PaU.o.o.c lo.ss.ls. p. ..)4, PI t 9 fig. ^J^' Orthocnas nodicostatum, M'Chksnky. Chicago Academy of hc.ouces, \ ol. ., p. oo, 1 l.Ut i.x, 1.^. 5. This species is of connnon occurrence in the shales of the Niagara ..•roup in New York. It is found in the lower beds exposed at Waukesha and near Wauwatosa, in Wisconsin. The specimens are casts, usually preserving only the marks of the strong annulations, which vary (con- siderably ''in their sharpness and degree of elevation; but there is no evidence of specific distinction among the forms of this character. The fine undulating transverse striiB are preserved in the impressions of the exterior surfiice, associated with the casts. Ortiioceras column are, Hall. pl.vte xix, figs. 4-0, 8. Orthoceras coluMnare, IIali.. Rep. Progress Geol. Survey Wisconsin for 1859. Feb., 18G0. ' Mnpare 0. canaliculalum, Sowehby, Silurian System, 1. U, fig. 20. The species described by me from Wisconsin is elongate cylindrical, , very .n-adually tapering. The siphuncle is central, of medium size, and not expanded between the septa. The septa are distant about one half the diameter. •/■' G8 T)ic- surface is longitudinally llutod hy low ridges which are about one- sixth of an inch distant IVoni each other. Tliis feature is of course varial.le upon specimens of different si/.e. The intermediate striiB are not preserved in the casts, in which condition the species is usually found. In the typical specimens, the septa are very distant, and in this respect it is conspicuously dilferent from 0. lo.nas, which has a very similar external character. This character may be subject to some variation. Fomation md Xo«<%.— This species occurs in strata below the Racine and Waukesha beds proper, and in the s..aie horizon with 0. uniutlatum.*' Ortuockras medullare. Hall. PLATE XX, rias. \, -1. Orlhoceras medullare, Hall. Rep. I'ro,^. GeoL Survey Wisconsin for 1859 p. 4 Feb., 1860. Ortlwcems slrirvlineatum, M'Ciiesney. xNevv Paleozoic tossils, p. 94. iub., 1801. Shell cylindrical, often a little compressed, gradually, and in some speci- mens more vapidly tapering. The septa are distant nearly half the diameter, but are subject to considerable variation in the same mdi- vidual, so that nearly three chambers are sometimes included in a length' equal to the diameter. The siphuncle is large and slightly expanded between the septa. The surface is marked by strong, sharp, subequal longitudinal stria^ which are ouicellated by fine transverse stride. The longitudinal stnoe are often alternated by finer sharp strijB in the same direction. Surface of the cast smooth, and by this character it is distinguished from the casts of 0. colummre and 0. angulatim. Fomation and Locality. -\xi limestone of the Niagara group, at \Yau- kesha and Wauwatosa, Wisconsin. ♦The Or. W. li<27. Orthocerus angiiliitum, Ihswuv.n. I^elhea Siiecica, p. "JS, Tub. .\, li;:. 1 . Orthocenis i-irnl.i;.;y N. Y., II, p. -i'.'l, I'lalc >.\iii, li^s. '_', ;'.. Compare O. canitiicululum, Suwkuhv ; in Mlucihso.n '.s Siiuiian System, p. 0:i2, Tal). .\mi. Hi: Specimens from Wisconsin are apparently identical with those of New York referred as above ; the former being casts of the interior, while the latter are preserved in a soft calcareous whale, and have the surface markings more or less obscured. The septa are distunt about one-fourth the diameter of the shell. The siphuncle is central or subcentral, with scarcely an apparent expansion between the septa. The longitudinal ridges are angular, and about one line distant when the shell is an inch in diameter. The finer surface striiie are but imper- fectly preserved on the cast, and it is only in the i«ipressions of the exterior that these markings become conspicuous. This is prol)a1)ly the species described by Mr. M'Chesney, in a paper published in 1801, under the names 0. scammoni, 0. hoyi, 0. lineolatum, O. irreffularo = 0. ivoodworthi. The Itxst one tigured in a fragment less than an inch in length. A gutta-percha cast sent by Prof. Winchell under the name 0. scammoni, corresponds very well with specimens referred by me to 0. aiigidutum. Should the species prove distinct from the European one, we may select a name from among those above cited. The com- parison of a considerable collection of specimens from Bridgeport and the various localities in Wisconsin has not convinced me that we have so large a number of species of a character so similar as those above cited. Formation and Locality . —In limestone of the age of the Niagara group, at Racine, Wisconsin, and Bridgeport, Illinois. Orthoceu^s crebescens, n. s. PLATE XIX, FIG8. 1, 2, X Shell large, rapidly tapering; transverse section circular; septa deeply concave, four and a half of the intervals being equal to the diamet'?r of the shell. Siphuncle moderately large, central or subcentral, 70 .>tr()iihell, caused by vith which it is circular section have not been ;roup, at Racine, nstriction of the deeply concave, i measured; the 1 the diameter of rcely constricted smooth ; exterior e interior, and is iual enlargement cted. The shell The siphunele is 3 junction of the 1 where the shell group, at Racine, 71 Ortiiockuas ahnohmr, n. s. IM.ATK XVm, FIO. Ill; I'l.ATK, XXV, Kit). IX. Shell large, gently carving and rapidly expanding from the apex; trans- verse section circular ; septa distant, the space of three nieasured on the convex side nearly equal to the diameter of the outer mar-in of the larger one measured, their distance gradually increasing with the diameter of the shell. Siphunele central or subcentral, very large, its diameter nearly Cfprnliug one-half the diameter of the shell, greatly constricted at its junction with the septa. The siphunele is partially occupied by a central core, or a replacement of organic deposition, with radiating ramifications which reach the outer walls^of the siphon, and are connected with the lilling between the septa. Surface characters, form of outer chamber and aperture unknown. The peculiar features of this species are the curving form, giving some- Avhiit the aspect of Cyrtoceuas with the character of septa and siphunele of OiiTiiocEUAS. The distant septa and extremely large siphunele, witli the partial lilling observed in numerous specimens, are distinguishing features. It is a large rapidly expanding form, the specimen (igured measuring about live inches in length with the outer chamber preserved, having a diameter of two inches and three-tenths, the greatest curvature l)eing in the lower part. Other fragments identified with this species, show the same curvature as the one hgured ; while as they increase in size towards the outer chamber, the curvature diminishes, and the extreme portion is prol)aldy quite straight. The organic deposition in the centre of the siphunele has the aspect of a shrunken flexil)le or sub-elastic tube, with slender tubular ramifica- tions which extend to the exterior walls, and appear as if they might have communicated to the chamber without, since the slender rami are now continuous with the matter filling these chambers. This central deposition of matter, with radiating rami, presents clmr- acters identical with those on which the Genus Actinoceuas of Broxn was founded. I have heretofore indicated their irregularity and want of symmetry as an argument against their^rganic structure. M. Baurani.e regards these features as due to an organic deposition within the siphunele. Such an origin would account for their generally characteristic features and their absence of structure, which would certainly be indicated in ,/6 72 some specimens, liiul the parts been at all shelly in texture. At least one other species in the same lormation preserves a similar feature in the siphuncle. Fonnation and Lnctdity— In limestone of the age of the Niagara group, at Racine, Wisconsin. OUTHOCERAS XIAGAitEXSK, X. S. 1>LATE XX, KKi. I!. Shell ehmgate, g.-duall- tapering; section broadly elliptical; septa deeply r-^cnve, depLh of cham})er about five lines where the diameter . nit nd a half inches ; siphuncle eccentric. Surface annulated ly low r < nded undulations which are from one to two lines dist^int, according to the size of the shell ; intermediate spaces regularly concave. In the larger parts of the shell there are abt)ut three annulations to each chamber. The finer surface markings unknown. This species in its young state is rather slender and very gently taper- ing, and, though attaining a pretty large size, is not as robust as niost of the associated forms. It bears considerable resemblance to the Niagara shale species which I have referred with doubt to the 0. imbrmihim, Waul.; but the annulations are not so sharply elevated, and the septa are comparatively more distant. The section, in all the specimens examined, is elliptical. It is possible that this may be the species described by Mr. Billings under the name 0. oberon, the principal differ- ence being in our specimens the prevailing elliptical form of the tube. The specimen figured is about nine inches in length, and is represented of the natural size. Fonnation and Localit>/.— In limestone of the age of the Niagara group, at Waukesha and Pewaukee, Wisconsin. cave fully the 11 obscu space obser condi The sir more rapii figured is The sp external i that it Wii specimen northwesi ascertaini stone has more rese bay. A ( filling of exterior i: me to ref G. 1 Orthoceras loxias, X. s. PLATE XIX, FIG. 7. Shell of medium size, elongate, somewhat rapidly enlarging from the apex; section circular; siphuncle central or subcentral, scarcely constricted at the junction of the septa; septa distant about one- fourth the diameter ; chamber of hal)itation unknown. Surface marked by sharply angular longitudinal carinjc with regularly con- 78 ''f'/ lire. At least liar leiiture in S'iagiira group, liptieal ; pepta les where the itrie. Surface oiu one to two ■mediate spaces there are about rl'ace markings ^y gently taper- )bust as most of to the Niagara ! 0. imhricaUim, , and the septa the specimens be the species principal differ- 1 of the tube. d is represented i Niagara group, cave interspaces, which, on the larger part of the shell, are distant fully three-sixteenths of an inch and gradually converge towards the apex. The shell is silicified so that the finer uiaikings are obscured, but there are indistinct transverse striie crossing the spaces between the lidges. No line longitudinal stna' have l)een observed, though they may have exi.-ted on the shell in its oiiginal condition. The similarity of this species to 0. ealmnnare is ()])vious, but it tapers more rapidly, and the septa are less distant. The length of the specimen figured is about eight and a hall" inches. The species has been illustrated in this eonnexion from its general external similarity to figs. 4, G, 8 and 9, and from a belief, originally, that it was from the same horizon, or not far renK)ved ther Vom. The specimen has been a long time in my possession, and was obi..iri i in the northwestern lake region many years since, but I have no .noans of ascei'taining the particular locality. The weathered surface of the lime- stone has the aspect of the Niagara limestone; but the l.csh fracture more resembles some beds of the Clinton group, in the 'nnity of Green- bay. A critical examination of the rock, the nature of the crystalline lining of some of the cavities, together with the silicification of the exterior shell and the principal part of the interior, septa, &c., induces me to refer the species, with some hesitation, to the Lower Silurian age. G. w. 10 irging from the !entral, scarcely itant about one- vnown. Surface th regularly con- iff 74 CRUSTACEA. In the Anmnl Report m the Gcoloyu of Wisroitsin for 18«i() (pub- lished in ISC.l), 1 described two new species c.f Iix^nuh, a new Calymknk, and a species of Dauianitks,* an/? are more prominent. The more conspicuons dilVerence, h.>wever, is the prolongation of the posterior angle of the c-heek into a short strong spine, a feature which I have not observed in /. hitrriviMs. The pygidimii is also more nearly .semicircular, being broader in proportion to its length. FomnHon anr- tions of the thorax. It has sometimes attained a very large size, the head being two and a half inches in length; c(pialling in si/e the largest head ligured from the Niagara shale of New York. Ill.'exus cuniculus, n. s. Cr,.VTK X.Nll, I'lO. 1-'. Glabella sul^. ladrangular in outline, broadly rounded on the anterior margin, w th the edge sharply recurved; general surface regularly convex, a little more arcuate transversely than in a longitudinal direction; length and breadth very nearly equal. Palpebral lobes moderately elevated, somewhat triangidar in form, and laterally produced; situated very near the occipital border. Suture line reaching the posterior margin of the head, a little within the outer angle of the eye lo])e, and slightly indented in front of the eye; thence directed toward the anterior margin with a. slightly sigmoid 78 curve; the distance between the sutures on the anterior margin Imt little less than in front of the eyes. This species, in comparison with /. armatus, J. bamcmisand J. impenttor, has the glabella more elongated, while it is less convex than I. hmi/nis, with shorter, and laterally more produced, palpebral lobes. The posterior position of the eye lobe is likewise a distinguishing feature. Formation and LocalU>/.—ln lirueston,- of the Niagara group, at Wau- watosa; and a single specimen of doubtful locality, received from Mr. I. A. Laiuiam, has the aspect of the Bridgeport rock. GENUS BRONTEUS, Goldfuss. BUOXTEUS ACAMA8, N. S. ri>ATH XXI, FlUS. lit, '-M; I'LATE XXV, FIG. 21. Bronteus occasus, W.xcii. & Maucy. Men. Bost. Soc. of Nat. Hist., I, p. 104, Plate iii, fig. 12. A cast of the head is broad ; depressed convex ; the anterior portion plain ; dorsal furrow extending a little more than one-third the entire lcn<'th. A single glal)ellar furrow, with a distinct anterior lobe, are visi- l)lc° The palpebral lobe is comparatively l)road and moderately elevated. The pygidium is somewhat semi-elliptical or parabolic, wider than long ; the axis is short, somewhat semi-oval, with one or more transverse furrows near the anterior margin, while the terminal portion is marked by two faint longitudinal depressions, which are scarcely defined grooves. The median rib, at its origin, is about twice as wide as the lateral ones, increasing gradually, and below the middle of its length more rapidly, to the margin ; where it is four or live times as wide as at its origin, and entirely simple. There are seven lateral ribs on each side, which are very slightly elevated, and the four anterior ones curve gently forward. The si)ecimens are lor the most part casts of impressions, so that the entire surface characters cannot be ascertained. The head is imperfect, the occipital ring and cheeks being broken off; but there are several nearly entire pygidia in the collection. The pygidium of this species resembles the Bronteus planus of Co!U)a, as illustrated by Barranue {St/strme Silurien du centre de la JJo/ihie, PI. xlii, fig. 34, and PI. xxxviii, fig. 3), and it is difficult to point out dis- tinguisliing characters. The head associated with these pygidia is more neiu-ly like that o^ Bronteus tenellus (Barranue, ut sup., PL xlvii, figs. 30, 37); but it differs IVom that in some important particulars. This spe( York. {Fo Plate XXV, Winch ELL u Formatm Wisconsin. jicidaspis di A. it Head tram anteri spine^ in fro than slight with rise 1 a nea thef This sj illustratec in being i the straig whether i Avhich is specimen the crem him. Formal Bridgepo rior iniirgiu Imt ;and7. imperalor, than J. insii/nis, 1. The posterior ure. group, at Wau- lived troin Mr. I. J. 104, Plate iii, flg. 12. ! anterior portion -third the entire •ior lobe, are visi- Jerately elevated, jolic, wider than [• more transver.se portion is marked Y defined grooves. 5 the lateral ones, gth more rapidly, 1 at its origin, and h side, which are ; gently forward. ;sions, so that the lead is imperfect, there are several s planus of Coni)A, • de la Bo/lime, PI. to point out dis- se pygidia is more , PI. xlvii, figs. 30, liars. 79 This species has the pygidia more elongate than B. magamisis of New York. {Pal. N. Y., Vol. ii, p. 314, PI. Ixx, lig. 3.) The figure given .m Plate XXV, iig. 10, is made fnmi a specimen connnunicated by Piot. Winchell under the name of Brontcus occusus. Formation and Locality/.— In limestone of the Niagara group, at Racine, Wisconsin. GENUS ACIDASPIS, MuttcmsoN. AcmASPis uANAi, Hall. PLATE XXI, KUiS. K, !). Jcidaspis danai, Hall ; in Catalogue of Fossils, Geol. Wisconsin I p. 423. 18G2. J. ida, WiNcn., Mau. ; in Mom. Bost. Soo. N. II., I, p. lUO, Plate in, fig. 13. I8(.o. Head transverse, somewhat quadrangular, about twice as wide as long; anterior and antero-lateral border ornamented with nodes and short spines. Glal)ella strongly defined by the dorsal furrows, narrower in front than at the base; distmctly lobed, the middle lobe larger than the others, separated by deep, strong furrows. A strong, slightly diverging spine from each side of the base of the glabella, with a strong node or short spine in the centre. The ocular ridges rise a little in front and one side of the glabella, and continue in a nearly direct line to the base of the eyes which are in a line with the front of the anterior lobes of the glabella. This species more nearly resembles Acidaspis vesiculosus, Beyrioii, as illustrated by Bahuande (PI. xxxviii, fig. 13). It diflers from that one in being more transverse, in the narrower front of the glal'^Ua, and in the straight instead of curving ocular ridges. We have not ascertained whether this species has spines from the posterior borders of the cheeks, which is probable, as in the allied European species. Fig. 9 is from a specimen communicated by Prof. Winciiell, but I am not al)le to detect the crenulations on the anterior border, as shown in the figure given by him. Formafion and Locaby.— The original specimen is marked as from Bridgeport, near Chicago. 80 GENUS LICIIAS, Dalman. LiCHAS lUlKVlCEI's'? HaLL. I'l.ATK XXI, VU.S. IJ 1.1, 11. Lii-haa breviceps, Hall ; in Transactions Albany Institute, 1 V, p. 222. 18G2. The t^pociinens ligured are a head, whieli in all important characters corresponds with L. breviceps as described by me. Tiie pygidiiim, fi-'. 14, occurs on the same specimen oi' rock, and corresponds in size to the head, both ligures being enlarged two diameters. The pygidium diflers from the pygidia associated with the head of L. hret'icqm in the Waldron locality only in the central posterior indenta- tion, and in this respect corresponds with L. nemis, which it otherwise closely resembles. It is thereiore unnecessary to propose any other name until we have better material. Figs. 12 and 14 are irom Bridgeport, Illinois. The specimen lig. 13 is from Gral'ton, Wisconsin, and is repre- sented of the natural size, the terminal portion having been restored to correspor\d with lig. 14. LlCHAS (Sl>.). The pygidium of a species of this genus in limestone from Grafton, Illinois, has a strong rounded axis, with four rings besides the terminal one. The lateral lobes are somewhat convex, but the extremities are broken off, so that its entire form cannot be determined. LiCHAS PUGXAX, WlNCTI. AND MaR. PLATE XXV, FIG. 20. Lichas pugnax, Winch. & Marcy, Mom. Bost. Soc. Nat. Hist., I, p. 103, Plate iii, fig. 10. 18C5. The ligure given is of the pygidium of the original specimen in the collection of Prof. Marcy. Formation and Locality.— In the Niagara limestone at Bridgeport, Illinois. LiCIIAS OBViUS, N. s. PLATK XXV, Fia. 19. Glaljella gibbous, broad in front, length equal to the width between the eyes; occipital and dorsal furro^ ^i^'ply defmed; lateral lobes simple, of nearly equal width throughout, suddenly contracting near the base ; surface finely pustulose. Formation and Lomlitij.—ln limestone of the Niagara group, at Lyons, Iowa. From Dr. Farnsworth. Sphferexochns Sphcurexochui lSph(Brexochui This spec minis of Eu for compari of the head European s so abrupt, i are more fr part of the This Ibsi localities o Calymene m Calyinene bl This spc Wisconsin, exterior ci Pygidium eleva sion are r not t This sf in the gr( there are 562. taiit chiiiiicter.s {j;idiiuu, fi;^. 14, ;ize to the head, the head of L. Ulterior indenta- ch it otherwise any other name om Bridgeport, in, and is repre- been restored to 2 from Grafton, ies the terminal extremities are late iii, fig. 10. 18C5. speeimen in the ! at Bridgeport, dth between the ed; lateral lobes contracting near group, at Lyons, 81 ^-^ GENUS SPH.EBEXOCHUS, Bkyrich. Sl'lIiEREXOCHUS ROMINGEUI, IIaLL. I'LATK XXI, FIGS. 1-7. Svhftrexochm mirvs, of uuthor.s; not S. mirus of ISeyiucii. s'phcBrexochus romingeri, Hal... Ceological Ileporl of W iscons.n p. 4,U 1H(, _ ifphcBTcxochus vurv3, 11A,.L ; in Twentieth Rop- State Cab., Isl eU.t., p. m. Win . This species was at first supposed by me, to be identical with the S. mirus of Europe, but a farther careful study of it with larger collections for comparison, has shown certain dilVerences in the form and proportions of the head, size of the cheek, etc., warranting its separation from the European species. The annulations on the axis of the pygidium are not so abrupt, nor the posterioi- extension so great ; while the lateral lobes are more free at tlieir extremities, giving a very different aspect to this part of the fossil. This fossil is pretty widely distributed, occurring at nearly all the localities of the Niagara group in Wisconsin and Illinois. GENUS CALYMENE, Brongniart. CaLYMENE NIAGARENSI8, HaLL. Cabjmme magarensis, Hai.l. tieological Report, 4th District, N. Y., p.llOl, lig. 3. Culymene blumenbachii var. niagarensis, Palaeontology of New \or\<, vol. n, p. oO, . This species occurs in nearly all the localities of the Niagara group in Wisconsin. Its most comuum condition is that of impressions of the exterior crust, whil. casts of the interior tire less frequently obtained. GENUS ENCUINURUS, E.mmerich. Encrinurus nereus, n. s. IM.ATK XXI, KUi. I'l. Pygidium triangular; length and breadth abcjut equal. Axis sharply " elevated and marked by about eighteen rings, with a farther exten- sion upon which no markings are distinguishable. The lateral lobes are marked ))y eight or nine distinct costue, which, in the cast, are not tuberculated. This species dilVers from the one in the Clinton group of New York, in the greater number of ribs on the lateral lobes of the pygidium, while there are fewer annulations on the middle lobe. Q. W. 11 1801. lubes is f^pecies i Gcoloi Wiscon.s 82 "'Formation an.l L.caUtj.-An limestone of the age ol" the Niu^nra .roup, ,, ,„ , ;a Kaciue, Wisconsin. 1 ontology GENUS DALMANIA, Emmeuich. DaLMANIA VKilLANS, ILvLL. VLATK XXI, FICiS. 1«, 17, 18. W,„.,„to f,ga...., Il,,u,. llc-p. lT»Br.s. Clcl. S,„.v„, of NVi.c„„si„ for ISW, p. (51 (ieueral lb™ ol' body not deter.ninc-d. Cephalic shield convex «e,ni- elliptical, tlie breadth about twiee a» great as the length (exelu.ive „r tlie frontal projeetion) ; tlie border is extended in front mto a tn- angnlar Uattened process, the base of which is little less tha,. one- half as wide as the width of the anterior portion of the glabella. In older individuals this projection becon.es more obtuse and so.ne- tin.es rounded; the lateral borders are broad, Uattened, separated from the cheeks by a distinct groove, extended post,,norly n>to spines which are e,ual in length to the glabella C-l.beUa large, depressed convex, widening in front to twice rts w.dth at the poste- rior nmrgin, divided into lobes by three pairs of transverse lurrows exclusive of the oceipiha furrow, which is distinct and conUnuous The two posterior furrows are distinct at the sides, but do not extend ..nlirely across the glabella except in very faint depressions, ihe „„teri„r- furrows are deep, very distinct, situated ^ "<"-; find the eyes, extending eacL 't one-third across the glabella, and .,ivi,„, to the frontal lob,- . transversely elliptical outhne. ihe LioRal ring is narrow, ornan.ented on the nriddle by a su.gle short harp spine Eyes very pronrinent, short rendor.n, conta.nn.g 1Z thirty-hve vertical ranges o, lenses, the middle ones ol wh.ch tave nine each. Cheeks small, pronnnent on the anterior porUon, narked near the posterior margin by a deep groove the cont.nua- tion of the ocipital furrows. Thoracic segnients unknown. yg- dTum son,ewhat elongate triangul.-.r, extended posteriorly mto an ute spine ; central lobe or axis urarked by ten or twelve narrow r' the lateral lobes less prominently nrarked by ten tta tened ' il« which 'erminate in a narrow flattened margm. tight ol these I-ibs'are double throughout their entire length ; the posterior ones are rtirectcil obliquely Iv.ickwards. Conipar t'oiiiptir Coinpar Verauri Ceruun A cai given b glabella I am in another species In t] have di an imp (luge di anterio just an This by M. and Ai ; Beyuic 3 Niiii^iira sjroup, for 1800, p. 51. 18G1. aid convex, semi- length (exclusive in front into a tri- tle less than one- 11 of the glabella. oljtuse and souie- iittened, separated i posteriorly into L. Glabella large, vidtlt at the poste- t)'andverse furrows ct and continuous. , bat do not extend depressions. The a little anterior to s the glabella, and tical outline. The le by a single short niforni, containing iddle ones of which le anterior portion, 00 ve, the continua- ts unknown. Pygi- posteriorly into an 11 or twelve narrow ed by ten flattened fin. Eight of these he posterior ones are IK.. ' 83 This npecies somewhat rQ>>L'inhhH U.limdiiras {Piatoops /imi/unis, hviiv- ontology N. Y., II, Plate 07, lig. 1) i l>ut dill'ers in the proportionally l'"'.'A^'»- glabella, the larger ;iud more promi- nent cye^, and the extension of the anterior border. The pygidium is less rounded on the anterior margin, the s[)ine is more obtuse, the tlat- tened margin outside of the ribs is narrower, and the number of ribs on the lateral l„bes is greater. In ligs. 13 and U, the head and pygidium of this species are represented. Gcolok. Sy.sl. .^il. .lu C'citie de la liohnnc, p. , b2, 1 late 1 1 . Compare Cheirurus insigiiis, CouDA. Prod., p. 133, Plate vi, fig. ,0. Ceraurus insignis, Hai.l. Pah.ontology X. Y., II, pp. 300, 30li, Plate 67, hgs. 9, 10. Cemuru^ insignis. IIali. ; in Twentieth Rep. Stat- Cab., 1st edit., p. 335. ISO- . A careful comparison of our specimens with the ilgures of 0. insigim, given by BAUUANnE, shows certair aiilerences in the general form ol" the glabella, the direction of the furrows iind form of posterior lobes, which I am inclined to regard as of speciiic importance, and tlusrefore propose another specific name. The New York and Wisconsin specimens of this ; species preserve the same characteristics. In the collection loaned to me for examination by Prof. WixNUHKLl, I have discovered the hypostoma of a Ceraurus attacshed to the front of I an impertect glabella, which I infer belongs to this species. This appen- : dage diilers from the hypostoma of 6'. insiynis in l)eing more i-ounaed ; anU'riorly, and not so deeply notched at the sides, while the border ; just anterior to the notch is not expanded as in the European species. This species was, 1 believe, lirst identilied with the European C. in.si(/iii.^ \ by M. E. DeVeRxNEUIl, in his memoir on the parallelism of the European ' and American palajo/oic tbrmations.* A comparison with the ligmes of ; Beyricii then satisfied me that our species was identical with the Euro- * JiuUdin Soc. Gol.de France, 1847. .',,» 84 pean one, and I expressed this opinion in Vol. ii, Pal(eoniolo/ Natural llidurfj^ entitled "An Enumeration of Fossils collected in the Niagara Limestone at Chicago, Illinois." HOLOOYSTITES, HaLL. (Page ssa.) I had overlooked the fact that the name Holguystis had been proposed by Lonsdale for a genus of corals. The difference of the terminal syllable has in many cases been regarded as a sullicient distinction, and is perhaps preferable to adopting a new name. Should it be objected to, however, I propose the name Meuauystites. ICHTHYOCRINDS 8UBANGULARIS, HaLL. (Pat'f 307.) The following figure, from a specimen kindly loaned me by Prof Marcy, and which I suppose to have ))een used in the description of /. corbis, shows the form and arrangement of the plates of the base and and lower parts of the rays, diftering in no essentiiil particular from specimens I have identified with I. mbaniiularis* The suture lines of this specimen had been marked with pencil, previous to coming into my hands, and it shows distinctly the series of tlirce radial plates as well as subradials. The specimen from which my description and figure of L sabangularis was made (Plate xi, fig. 15, of this paper), is from Bridgeport. It preserves the substance of tbe plates, and is more fit for comparison of external characters thanintermil casts alone. Besides the specimen used for the diagram, there is, in the collection of Prof. Marcy, another one which equally shows the structure of the * The basal plates proper of IcnTHYOCiiuvus have heretofore been shown by me to be undeveloped externally, or are covered by the summit of the column ; and the lower plates, shown on the exterior of the calyx, are properly subradials, the basais being too nnnuto for representation. huso, (ir«t an.l secoiul rmlials. Both .specimens uiv casts ..f the interiors „r the fossil, and show not only the real strnctnre, hut the ..hscurely anj^iilar Ibrrn of the lower part of the hody. ACTIXOOIUNUS (SaCCOOHINUS) WHITFIELUI, IIaI.L. An evan.ination of the ligure, and a subsequent examination of a specimen labelled Mrol^tocnms marcomnm, in Prof. Maucy's collection, and which appears to have been the original of the figure given, leaves no doubt regarding itn identity with .1. whitJicUi. The bifurcations ol the rays take place in precisely the same manner in the two individuals ; and dilferences as great as those indicated in the plates and lorm ol the body, can be detected between many of the individuals from Waldron, and are of no specilic importance. Proi. W. points out a dillerence ui the nuTnber of interradial plates, stating that they are always less than fifteen But in the two interradial areas of his specimen which show plates, on either of them can be counted lifteen plates, or even more than this number, if we enumerate the smaller ones in the upper part of the area. In one of the areas, sixteen plates can be distinctly counted. Mejistocnnus iufellx, W. & M., is only a snraller hidividual oi the pre- cedino- species, possessing all the ch.aracters of the Waldron specimens and none others. The number of interradial plates may appear less, as those of the upper part of the area are too small to be counted in a cast of the interior, especially since this cast is very indistinctly preserved in some of its parts. The constrictions of the interradial and anal areas between the arm-bases is a character common to all the Waldron speci- mens, when preserving the margin of the dome. This feature is wel shown in Saccocnms speciosus- figured by Rckmkh. Tiie bifurcation of the mys take place at the same height as in the Waldron species ol the .ame si/e ; the ridges along the radial series are subject to much varia- tion but these dilferences are of no specific value. Both Prof. Winohell's figure and specimen leave no doubt of the identity of this form with Actinocrinm tvlntjiddi. Megidocrinus mm, W. & M. The specimen communicated by 1 rol. WiNCHELL, under this name, I should regard as .1. (>S'.) whitliMi with the summit unusually constricted, but showing no marks of specific distinction. • The fossil referred by Dr. Rcemer to Saccoctxnus speciosm is probably not of that species, but more likely identical with the Waldron species. I am ir extra vagal on each s ones in thi of this a I depression This is so nearly more proj] small ante second sh and subct AVKJULA t WlNClIELL oblique at The hii Pteuinea, plate mer of Prof. \ tor a stroi the large not ally ii and until shall leav eric nann scarcely ^ tion to identity ^ inclined may be t 87 •r the interiors the ()l)seureh' L. iniiiuition ol" si cy's collection, •e given, leaves l)iturcutious ol" wo individuals ; md t'orni of the from Waldrou, , a dillerence in ilwajs less than len which show I, or even more tie upper part of jtinctly counted, dual of the pre- Idron specimens y appear less, as sounted in a cast iuctly preserved li and anal areas a Waldron speci- s feature is well lie bifurcation of on species of the t to much varia- Prof. Winohell's f this form with micated by Prof. 'vhitjieldi with the accific distinction. J not of that species, but Pentameuus (Pentameheix.v) ven'tricosus, Hai.l. I am inclined to regurd the /'. clilrajocnsis of W. & M., as only an extravagant form of the above species. Tlieir (igure gives live plications on each side, while the specimen (([uite imperfect) shows two strong ones in the centre, a nmch smaller one adjacent on the side; and outside ol' this a broad, low elevation, while the third one is not delined by any (lepressi(m between it and the margin of the shell. AVICULA UXDATA, HaLL. This is not to be regarded as a true Avicula, but as having characters so nearly identical with tlu)se of that genus, that this reference seemed more proper than any other. The species is not a Pterinea. It has one small anterior tooth in each valve ; and an oblique posterior tooth, with a second shorter one in the right valve. The muscular scar is large and subcentral. These characters appear to me more nearly those of Avicula than of Pterinea. The teeth are correctly described by Prof. W'iNciiELL as "posterior, linear, diverging teeth," which are (piite oblique at the posterior extremity. Amphiu(elia leidyi. Hall. (Piigc 387.) The hinge structure ol this species will not sanction its reference to Pterinea, made by Profs. Winciiell and Maroy. The striated hinge- plate mentioned by them, and which I have seen through the kindness of Prof. Mahcy, appears as if obli(pie or expanding outward, giving space for a strong external ligament, wiiile the large pit beneath the beaks does not ally it very nearly with Pterinea ; and until we know more about it, I shall leave it under its proposed gen- eric name of Amphiccelia, though it is scarcely worth while to seek any rela- tion to Lei'TODomus. In regard to identity with P. negleda^ I have been inclined to the opinion that there may be two species of this genus in ■.VA 88 thr rocks of Wisconsin and Illinois; numerous si.ocinu'.i. presenting dilVerenees of outline, which are easily reeo^^ni/al.le. The accompany- in.^ outline f.gures arc, 1, eopie.l from the ligure given l.y M'CnKSNKV .1 Au,ho,u,rl,ia ncyleda; and 2, from A„phicwUu lehhjl. It n.ay require farther comparison, with larger collections, to deu.onstrate the identity or diiVerence of these forms. PlATYOSTOMA NrAr.AIlKNSIS, IIai.l. (I'ligo aiK).) riahiccras cnmjmmdatum, W. & M., seems to he only one of the many phases assumed hy the above species, in its wide geographical d.stn- bution. PORCELLIA 8ENKX, WlSCM. AND MaU. g. " Shell small, consisting of one and a half or two very rapidly enlarg.n detached whorls, which are somewhat oblique in the young she I, but afterwards continue very nearly in one plane. Toward the aperture the shell is tlattened and subnodulous on the dorsum. The specimen is a cast of the interior of a Platyceras, closely allied to r. niajn,.nm; and the spire is oblique throughout its entire extent, the two sides of the shell being nowhere symmetrical. Ihere are a lew undulations on the back, from inequalities of growth at the aperture, which has been deeply sinuate; but there is no evidence ot the narrow carina (m the dorsum, or slit at the aperture, characteristic ot 1 oucellia. Pleurotomaria halei, Hall. (Page ;j«'2.) Notwithstanding the fact that Prof, Winchku. has identiHed P.nxion .„ the species he referred to P. Imici, the specimens wh.ch he sent to me '„„der the h.tter nan>e are not of that species, but of I'Umtoma.-u, .pecin,ens of the latter species, and one line cast ol P. /«t Thi- cunaitiou is clcul, shown in the original spocunen. jipu'i' tl<> not n ; n»»' '»* there le liitoral lobes, leaily show the «>r..". lohe should ght side be eon- riusr*^ <»t' the axis. ^f^ ' rigH'f ? - 'g ^? ^-??P^'?WP^''ff^^'^^^^^^^ A ^> IMAGE EVALUATION TEST TARGET (MT-3) 1.0 I.I 1.25 — t 1^ M IM M 1.8 U 111.6 Photographic Sciences Corporation 23 WEST MAIN STREET WEBSTER, N.Y. 14580 (716) 872-4503 w sss&sp?cv,f=- '.s^m •«?*::' #? ^ ///// CIHM/ICMH Microfiche Series. CIHIVI/ICMH Collection de microfiches. Canadian Institute for Historical Microreproductions / Institut Canadian de microreproductions historiques III. LIS ♦Cladop *C. c. *c. *c. Fenest *Lichen Polype *Stictoj 91 ^ii- III. LIST OF FOSSILS OF THE NIAGARA GROUP, OCCURRING IN TIIK WISCONSIN, ILLINOIS AND IOWA LIMESTONES. FORAMINIFERA. Receptaculites hemisphiericus, Hall. Geolog. lleport of Wisconsin. 18G1. R. infundibulus, Hall. Id. pa. = hchadites tessellatus, Winch. & MAU.f ZObPHYTA. Diplophyllum cmspitosuin, IIai.l. Pal. N. Y., II, p. 110, pi. 33, fig. 1. Favosite.s favosa, Gold. Pal. N. Y., II, p. 120, pi. 34 bi.s., fig. 5. F. golhlaiidical = V. niagarensi.s, IIai.l. F. niagarensis. Hall. Pal. N. Y., II, p. 12.'i, pi. 34 bis., fig. 4 a, b. F. striata, Say, in Amor. Jour. Sci., VII., p. 381 ^ .' F. favcsa. Gold. F. vemista (Hall), Winch. & Mak. Ilalysites catenulatus, Linn. II. macrostylis, Hall. Pal. N. Y., II, p. 135, pi. 302, fig. 2. lleliolitfS pyriformis, Guktt. Pal. N. Y., 11, p. 133, pi. 30 A, fig. I. ♦Petraia calicula (Hall) = Stnptelasma calicula, Hall. Pal. N. Y., II, p. HI, pi. 32, fig. 1. Stromatopora concentrica, Goldf. •Zaphreutis turbinatum (Hall) = Polydilasma turbinatum, Hall. Pal. N. Y.,II, p. 112. BRYOZOA. ♦Cladopora fibrosa. Hall. Pal. N. V., II, p. 139. *C. lichenoides, Winch. & Mak. C. reticulata. Hall. Pal. N. Y., II, p. 141, pi. 39, fig. 3. *(J. seriata. Hall. Pal. N. Y , II, p. 137. *C. verticillata, Winch. & Mau. Fenestella elegans, Hall. Pal. N. Y., II, p. 104. *Lichenalia concentrica. Hall. Identified by Winch. & Mah. Polypora incepta, Hall. Pal. N. Y., II, p. 107. ♦Stictopora punctipora. Hall. Identified by Winch. & Mak. ECHINODERMATA. Actinocrinus (Saccocrinus) semiradiatus. Hall. A. (Saccocrinus) wliitfteldi, Hall, — Jctinocrinus christyi, Hall. Apiocystitcs imago. Hall. Caryocrinis ornatus. Say. (PI. xi, fig. 17 of this Report.) Crinocystites chrysalis, Hall. Cyathocrinus cora, Hall. C. pusillus. Hall, = Lecanocrinus pusillus, Wixcn. & Mar. C. waukonia, Hall. Echinocystites nodosus, Hall. Eucalyptocrinus ciclatus, Hall. Pal. N. Y., II, p. 210, pi. 47, fig. 4. *E. chicagoensis, Winch. & Mah. E. cornutus, Hall. E. cornutus var. excavatus, Hall. E. crassus. Hall. Eucalyptocrinus obconicus, Hall. E. ornatus, Hall. *SiKH'it'S wlilcli liiive not oonio under tlip obsprvnllcn'. l>itis, ll.M.L. (loniiilincN stiles davus, Hall. (i. oliins, Mai, I.. (!. teiiax, llAi.i.. llciiiicosinites .siibfilolioRiis, IIai.l. llolycystiU'S almiinnis, IIai.l. H. alU'inatus, Hall. H. cyliiuliicus, Hall. II. oviitiis, Hall. n. sciiullatus, Hall. H. .splimiicus, WiNcn. & Mar. II windiolli, Hall. ld.thyoc.inu,s suhangulavis, Hall, - /• corbis, W.Ncn. & Mau. l.ainpterocriniis iiitlatus, Hall. Macoslylocrinus ■^<"''^"«; ";;.';': „ ^,^ _ Actinocnuus (Saccocrinu.s) christyi, Hall. Meglntiicruius marcouunus, A inch. a. mxh., ,.., v,-i, t Mah J/. .-nyWix, Winch. & Ma-... ^ .»/. m«rco,uHU,«, ^\"^^' " ^ ^ f"" W ./ds Win. ... & Mau = Actinocrinus (Saccocnnus) chnsty, Hall. Mclocrnu:::n.cu.H (T.oosx), Hall, =. .Vdmocnn.. .>J>Hra.n.<,h., ^V ikch. & Mau. iihodocrinus.' rectus, Hall, = Cnnoajstilcsl rectus, Hall. H (Lyriocrinus) sculiiiihs, Hall. r«W>.noc-n;L uer«c.n//. Tuuust. = Melocrinus verneu.h (Thoo.t). Hall. BRACHIOPODA. Atrypa nodostriata, Hall. Pal. N. Y., 11. p. 27'2. A reticularis, LiNN- . . , ,, n i v v TT n 2^8 Meristina nitida (Hall), = atrypa nit^da, Hall. Pal. xN. \ ., II, p. 2G8. Obolus conradi. Hall. Orlhis eletiantula, Ualman. 0. Habellilcs, Hall. o' hybrida, Soweuby. . ti , Pentainerus arcuosus.t M'C.esxky, = ? P. ventncosus. Hall. .p crassoradius.t M'Cmk^.nkv. .New Pal. I'oss.ls, p. 8, • 1861. ;;;;;:;::t;;™%iu.nau sy.c.n, =i> ........ m'chk«..v. ,,eideut>dis. HALL l^d. X^U I^ P^341^ ^ , ^ ^^_ ^;^;:::::;iw -^^:^us, hall, = ? r. c/.ca,oe,.ia, w..ou. . mau. Uhynclionellacuncala,UAL.MAN. H. ucjilucta, Hall. Pal. Is. ^ •, H. PP- '^, -'^' ►Spirifera crispa, Sowkuby S. P. P. P. F. P eudora, Hali gibbosa, Hall. ""^"' ^^T'c.,^^ AU ■ in .Jour. Acad. Nat. Soi. Phil., VIII, p. 26i. ;;S:Xuur::: =^'-.-s..s, hall; .......... M'Ou.skky. plicatella var. radiala, Sowkuby. siu.iUor. Winch. & Mau., = Pentamerus. Stropho.uena rhomboidalis Waul. oi. = S/ro^omena magarensis, W. & M. Strophodonta profunda. Hall, l ai. .>. i., ' l^" ' ^ .S'iro^omena macro, AV. & M. c semilasciata. Hall; in irans. Alb. lnh..iv, p.-i". . T;..uato;:;ra n.atthe..oui. M'Cuks.ky ; New Pal. Fossils, p. a. 18oO. .... I .iw.<.> tun sHPclos of Peutanifius as woUas ..^.:,:v:.riu":-t:s>^Si'" Lu":wi:.out ,.... .a. . .xpia.uuu,n ...• so ao..,.. S. s. s. s. s. s Bucania ai B. c B. c B. I Cycloneuii Euneuia ? *Jlolopea c u. ■ I H. *II. Loxoneiiij M urchin' M. M. *Platijcerc *P. 1 Platyosto Pluurotoi P. P. P. P. P. *P. Porcdlii Straparol Subulites 'I'reniano TrochoiK T. 93 .--•'•/ II. & Mau. ,) christyi, Hall. ALL. \Cii. & Mar. NEY. I. & Mar. >6i. 'CtlKSNEY. niagarensis, W. & M- homena macro, \V. & M. 0. of Penlanifrus us wuU as so UolDg. LAMELLIBRANCHIATA. Ambonychia acutirostia, Hail, — ./. mijtiloidcs, Hall. A. apliea, Hall. Ainphiccolia leidyi, Hall = .' Ambonychia neglecta, M'Cm-NEY. Avicula emacerata, Conhad. I'al. N. Y., II, p. 282. A. undata, Hall. I'al. N. Y., 11, p. 283. Conocardiuin niagarensis, Wlncii. & Mak. C. ornatum, VVixcii. it Mau. Cypricardinia arata, Hall. Cyinicarditcs .' (luadiilatera, Hall. Edniondia nilusi, Wlnuu. A Mail, — .' Modiolop.si.s nik'si. Modiolop.si.s dictrjus, Hall. .M. rectu.s, Hall, = Cleidophorus macchesneyanu.s, Wlncii. & Mah. M. .snbulalus, Hall. I'aUeocardia coidiifonnis, Hall. I'terinott brisa, Hall. *!'. cyrlodontoides, VVi.Mii. iV .Mah. *V. revolula. Winch it Mak., — ': 1*. sUia'costa, M'Cuksxev. P. volans, WiNCii. & .Mah. GASTEROPODA. Bucania angustata, Hall. 15. chicagOLMLsis, .M'Oukssky, New Pal Fossils, p. O'J. 1800. H. crassolare, .M'UiiEsXKV, New- Pal. Fossils, p. yi. 1801. 15. pervoluta, M'CiiESNKV, New Pal. Fossils, p. 'J 1. ISOI. L'yclonema ? elevala. Hall. Fuiiema.' tiilineata, Hall. •liolopea chicagoensis, Winch, it Mar. H. • guelphensis, Billixus. 11. bavnionia? Billinus. *II. niagarensis, WiNCU. & Mah. Loxonenia leda, Hall. Murclii.^' ••' conradi, Hall. M. liercyna.'' Billi.vgs. .M. laphami, Hall. *PUityceras campanulaium, Wi.ncu. & Mah., = Platyostoina niagarensis, Hall. *P. niagarensis, Hall, = Acroculia niagarensis, Hall. Pal. N. Y., II, p. 288. Platyostoina niagarensis, Hall. Pal. N. Y., 11, p. 287. Pleurotoinaria axion. Hall. gonopleura. Winch. & Mah. halei, Hall. haki, Winch. & Mah., := Trochone.na (('yi^loneina.') pauper, Hall. (Trochonema) hoyi. Hall. idia. Hall. sigaretoides, Winch. & Mar. Porcdliu nemx, Winch. & xMar., = Platyceras. Straparollus inopsus, Hall. Subulites ventricosus, Hall, = S. brevis, Wi.scii. it Mau. Trenianotus alplieus, Hall, = Jiclleruplwn {/iucania) perforatus. Winch, it Mah. Trochonema (Eunema) t'atua, Hall. T. (Cyclonema?) pauper. Hall. CEPHALOPODA. Cyrtoceras brevicorne. Hall. 0. dardanu.s, Hall. 0. fosteri, Hall. C. hercules (Winch. & Mar ) Liluitt's liercuks, Winch, it Mah. iti 94 Cyrtoceras lateralis Hall. (J. lucilluui, Hall. C. pusilluin, Uai.l. C. rigidum, Uai.l. (ion.i.hoceras scriniiun, 1Iall,= G. marcya, Winch. & Mah. G. septoris, Hall. Ijtuite.s inarshii, Hall. Nautilus capax, Hall, = Liluitea capax, Hall. N. occiduntalis, Hall. Oncnceras orcas, Hall. Urthoceras abnoriiie, Hall. 0. 0. 0. •0. 0. 0. *0. •0. •0. 0. 0. 0. alicmini, Hall. antrulatuin, Hall. aiiiuilatuiii, SowKRUY. cameolare, M'CiiK3NKY. New Pal. Fos.sils. 1861. colunmare, Hall, ^ O. scammmi, M'Ciiesnev. ^ew Pal. Jo.s.s.ls. crebescens, Hall. hoyi, M'CiiESNEY. New Pal. Fossils. 1861. laphami, M'Ciiesney. New Pal. Fcssils. 1861. lineolatum, M'CiiESNEY. New Pal. Fossils. 1861. loxias, Hall. meduUare, Hall. niagarense. Hall. ^ woodworthii, M'Ciiesney, = O. irrefrulare, M Lhesney. Phragmoceras nestor. Hall. Tiochoceras (Gyioceras) bannisteii, Winch. & Mar. X costatuin, Hall. T. desplainense, M'Chesnky. New Pal. Fossils. 1800. T. notum. Hall. CRUSTACEA. Acidaspis danai, Hall. Brouteus acamas, Hall, = lirontms occasus, Winch. & Mar. Calymene bluuieiibacbii var. niagarensis, Hall. Ceiaurus niagareusis, Hall. Halinania vigilans, Hall. EiK'iinurus nereus, Hall. llUviius armatiis, Hall. ]. cuniculus. Hall. I imperator. Hall. I. insignis, Hall, = ?/.«"0W/iena7iu«,WiNCii.& Mar. I. (Buniastus) ioxus, Hall. Lichas breviceps .MIall. ♦L. decipiens, WiNCii. & Mar. Ij. obvius, Hall. L. pugnax, WiNcn. & Mau. Spba;rexochus romingeri, Hall. Leperditia foiiticola, Hall. ISf.' IM'.' KRRATA Page *>7, lint! 2", I'"'' I<-lliijo<;rinuK read hMhi/ncriiuiH. Piigi! :i71, line Id, liolo Scrinus christiji — I'lifc'o :i7fi, line :U, lor Mndsikom roiid Linn. l>ago:WO, lim;:'.!. lor I'l.vrK Vlll reacl I'i.atk XIII. Pagt) -V^' li'"-' -H..'''"" iili'iitilloil »•(•(«/ clcsigiiiili'il. B SI, ill' M'lf I'l.ATK \. I'lmc :i7ii. , ,■ ,i,is MM.il.,. show in- tlu>characn-v> US. loMTibe-i. ., ,.n..c.ntiusj -me of th. int.Tra.lial airas. au.l tu„ of the radial Fi(i. -2.. View <'!' ail mt.TK.r cust, incMiUm!, serios. F... .. La.eva! view of a w.U pn-se.v.i .ast of tins species. ^',-)7'7M.s7>.7.- /•/•;.vv.i.v<.r/..i/.'/.s, //.././.. I'llSIr :ii!H. , , „,• .his snecies i.res.Tvin- tl.e iiupressioii, of tho plates. Fi(5. ^- All iiiteiniil cast ot this >i'u.it. , \ " MKI.nruiMS Vi:i! S lOI U, Tinx.ST. , , ,■ ,u; . <,K.cies Tlie const, in ion l.-.w.vn llu- arms i. not .,nite so deep Fio. .^1. An inlenial castnt lhi>siKon..-.. as in some examples. A.,i//-n;/f«''';/vrs i-.n.iTrs. Il.u.i.. Fui IJ- • the plates in an nmisnal «c ., , A view of the externa, sur.ce as ohta.ed from -. -1-;;;-;,:- ^ !.r''' T 10. Lateral view of an internal cast ot this >pe< ..■>. 1 he Piim' :!7o. „1W «oll „n..'.vi..l ml«ra»l .-ast, on ivl.id. il..- l.mi.d.ries of CUV Hne of the arin-hase: ■'vr^- ^•^(•l•ibe^^. I) of tho radial III unite S'l iltep tlie tiiiii'kiniis of he natural mould. laturnl mould, rokeii otl'. 1 the luvundnries of een thix species and ist being fhe strong upvinsi this position 1 downwards to the . Ml /. ' PLATE Xl. EriAl.YI'TittlilMS OIICOMCIS, ll.ll.l.. f'lQ, 1. Lateral view of « siKHninou of this species, showing the structure of the body and first bifuri'utioii of the rays. , h'rr.{i.yi'T. Basal and lateral views of a gutta percha cast njadu in the natural mould left by the removal of the substance of the crinoid. I'VATIIOCIUMS WAIKOMA, HaLL. I'Hhe .itiT. Figs. U, 12. Lateral and basal views of an internal cast of this species. ('iATUdCNLMS COL'A, HaLL. Fig. 13. View of the anal side of a specimen of this species, shoM-ing the position of the anal plate. " 14. Lateral view of a larger individual of the species, showing more distinct'y the radiating lines of the plates. (Some larger specimens ob.served are very decidedly constricted above the base.) ; < f .1 . \lur- N.l' II. -1 .'ll I III \IIJ III \ If \mi\y and first structure of the >in a gutta-percha the surface inark- i the impressions w,. vated ba^ie. the crinoid. The ,p of the specimen, mould left by the of the anal plate, ict'y the radiating ;idedly constricted Fio Fin Fig PLATE XI— Continued. IVUTUIOVHIM S sritA.Mill.MilS, ILm.U Page litrr. Fio. 15. Lateral view of a specimen from Bridgeiw-t, Illinois, preserving the substance of the plates. . • n 1 " 16 View of a specimen from VValdron, Indiana, from which the species was origmally de- scribed. ('MiYOClUMS 0I{.\ ATI'S, SAY. Fia. 17. Lateral view of an internal cast of a specimen of this species, possessing the usual characters of the species as they occur at these localities. Ciiyi'Toniscis. F.o. 18. The calyx of a Crinoidban ? of a now and peculiar type, for which the name Cbtpto- DisoiJS is suggested. SI. Ill' \ll riA TE All. HohOVYSTITES SCUTKLLATUS, UALL. I'lVge ii')7. Fio. 1. Lateral view of the specimen described. The plates on the left side are obscured by adhering rock. HOLOCYSTITKS UV'ATUS, HaLL. Page 357. Fio. 2. Lateral view of a specimen of this species HOLOVYS'lTl'ES WIXVHELLI, HaLTj. Pa«e 356. Fi8. 3. A view of the specimen described, which is imperfect at the base and summit. HOLOCYSTITES CYLINDRICIH, HaLL. Page 354. Fk>. 4. A view of a well preserved individual of large size, on which the limits of the plates art' strongly marked. " 5 V V,- of a smaller individual. , , x „i,;„k fha « 6 Vkw of a small specimen (preserving a portion of the short column), on wh:ch the angular prominences of the plates and the surface pustules are well preserved. HOLOCYSTITES AliiXOEMIS, HaLL. Pago 355. Fiu 7. Lateral view ot a cast of a large specimen, which preserves the Umits of the plates and the minutely pustulose texture of the surface. . , , t. » 8 View of IsmallL'specimen. The peculiar arrangement of the plates m the lower part of the body is seen in both this and the preceding specimen. HOLOCYSTITES ALTERNATUS, HaLL. Page 355. Fia 9 View of a very distinctly marked specimen of this species, showing the position of the summit apertuve and the arrangement of the plates of the body. ECHINOVYSTITKS .\ODOSUS, HaLL. Pago 'M). Figs. 10, U- Lateral and sun.mit views of the specimen described. Apiocvstites imago, Hall. Page ;io8. Fia. 12. Lateral view of the specimen, .showing the structure of the body and the position of the openings. Hemicosmites suiiOLOBOSUS, Hall. Page 359. Fig. 13. View of a specimen which shows the structure of the body. .,.# I..1.- \ll are obscured by summit. mits of the plates nn), on which the all preserved. ts of the plates and )S in the lower part the position of the d the position of the lib Fig. 14, Fig. 15 PLATE XII— Continued. GOMFHOCYSTITES GLANS, HaLL. Piige ^i. Fm 14 Lateral view of a cast of a specimen, which shows the general form, the position of the F,a. 14. Later^;^;;-;^^^.^^^ ^^^^J^, ^he spiral appendages of the dome, and .mpress.ons of some of the plates of the dou e and body. OOMPHQCYSTITES TENAX, HaIjI'. ,; ■ Page .S52. F.O 15 Enlarged view of a specimen from Lockport. New York, which preserves the plates of Fio. 15. E-l^^^^';^^;;;^^^^ J^^^ ,,,y ,,, d„„,e, showing their spiral arrangement and nodose character. PLATE XUa.* GOMPIIOVYSTITES TENAX, HALL. Page 352. F,« 1 Lateral view of the upper part of the body, showing the arrangement of V^^^^^'^^^ pra grooves indicating the places of the sessile arms are at the upper mar.ms of the ranwlaller platl The plates are more or less irregularly disposed m some parts of the body, but they appear, like others of the genus, to have a generally spiral arrangement. (Enl-.rged to two diameters.) . 2. The summit, shoeing the arrangement of the spiral arms and the ^^^' ^^l^^^^^^J^^ diagram is made from an imperfect specimen, and the position of the eccentric aperture could not be ascertained. GOMPHOVYSTITKS CLAVUS, HaLL. Page 'XiA. Fm. 3. A fragment (natural size), showing the disposition of the spiral arms and the obtusely angular form of the body below. ' ' ' (JoMl'IlOCrSTITEi) GLANS, IIaLL. , , '''"'" Page 352. ■ ■ - 1, F,a. 4. Lateral view of a specimen, showing the entire form and the disposition of the spiral arras. .. 5. The anterior ? view of another individual of the same species. .■ . - -7 HohocYSTiTES alternatus, Hall. ••■'■ ■'■' '- ' ■ Page 355. pia. 6. A posterior ? view of a specimen (natural size), showing the position of the eccentric aperture, form and relation of plates, etc. HOLUCVSTITES CYLINDRICUS, HaLL. Page 3^. View of a nearly entire individual, showing the central aperture in a depression at the summit The plates of the lower part are broken off. A smaller individual, in which the plates have been strongly ridged P^^^-^^^ ;°° of the column. The lower ranges of plates are somewhat obscure, and the dotted Unes indicate depressions, which may be sutures or only grooves m the larger plates. ArlOVYSTITES IMAGO, II ALL. Page ;«8. Lateral view of the specimen, showing the ovarian aperture on the left-hand side of the figure, and the right pectinated rhomb. (Figure natural size.) Crinocystites chrysalis, Hall. Page 302. Fio 7. « 8 Fio. 9. Fio. 10. " 11 View of the gibbous side of the specimen. Lateral view of the same specimen. "7^,^^^ accompanied the original paper «« Plato I. It i. now arranged with the other plates in it. order as XUo. Bute Mui. Nat. Hist. 30. iCYSTIDE^.i PI. 12 a (I) nent of plates; the ipper mariniiis of the rly disposed in some to have a generally ntral aperture. The ion of the eccentric ms and the obtusely position of the spiral sition of the eccentric in a depression at the d, preserving a portion ibscure, and the dotted res in the larger plates. le left-hand side of the •) he other plates in its order I' LATE Mil- DllOhl'S CONUADU llALh. S'mai'JionoNTA pkofvsda. Hall. c .u f ^. of tin. concave val/e of a small individual, with a portion of "".' °" ''',", ""ri, „f il„ .™,r«l ..1« of « largo WivWu.l. Th. «,».c,,l.r •■ ' ''"'';:™:.:,, u:«;il ». r«pr.»„« » .»»« » .ho, .« m .h. 0,1^,.., specimen. SVirlFKllA F.rriOKA, II A LI.. , ram- liTT. ":■ ■;:E;;t;;rLr;rr:3;r...e.i..v«.H, of .^o ,.„», .na *« .o^u and curvature of the area. Sl'IUIFEUA OIHBOSA, ILiLL. Page-378. Fia. 6. View of a dorsal valve of this species. " 8. Cardinal view of a specimen. SPIRIFKUA rUCATFLf.A \An. RAV/ATA, SOWERBV. PiVBe 378. F.r 9 Dor»lvi.wof.™.lli,.dmd™l,sh,«ngthoort..»ionofthoUm.tointhodors.l „' .„. v.nt;:l':i::T:,;:=^ni'i".ho„i„, *» o«.n.of *. !.».„. i. *„»«., valve. " 11. Profile of the specimen. Si'inii'KRA MKTA, Hall. PiiKe :!S0. '"• I. SlriirlAr:iJ\ndividual, showing the height and extent of the straight area. SriRfFFRA NOBIUS, HaLL. Page !W0. Ftg 14 Dorsal view of an individual of medium size. « " 15. Ventral view of a specimen, .showing plications m the mesial sinus. " 16. Ventral view of a large individual. " 17. Cardinal view of the specimen fig. 16. 1||^ il the fll'inif of e, the median ocesses. th a portion of of the ventral The muscular in the original and the height Ite in the dorsal Ibb in the ventral f the straight area PI08.18-21 Figs. 22-2^ PLATE XllI -Continued. ■ PEnTAMERl'S (PKNTAMKHKhl.A ?) VKNTRICOSCS, flM.L Pagi> Wi. Figs 18-21. Dorsal view, profile, cardinal and front views of a tr.^diun.-si.ed individual of the species, showing slight indications of plications on the mesial told and s.nus. PKNTAJrKHUS MVLTU'OSTATVS, HAUL. Pnge 381. Figs 22-24. Dorsal view, profile, and cardinal views of an internal cast of this species, preserving the impressions of the costae on the anterior margin. r I. ATE XIV. I'liKC :1M. „f .Kia «ni«-ies oartly ilenuded of the shell. The and poHterior teeth are also visible . AMIloSYilUA .irrrillOSTnA, IfM-l- PaKO :w:i. F,a. 2. View of the left valve of a full .'-own iiulividual. AMIiONYCIIIA M'll.r.A, IlMI" f „. ,. V»w or .h. « v.,.«, .l...m. i.n,«««o..« of t.» !...«> «>-. MoDIOhOJ'SIS HECTUS, IIALL. Cri'HKAHJtlMA .lAMVVl, //^.l/./- r,„. e. V»w or .be n*. ..r.e or . ....Unc, or Uu. .P.ci«. .r.he n..»^ ..». Moi>iohovsis nn-r.Kis. Uai.i.. Page !W6. P.. 7. View of a cast of the left valve, showln, impressions of the lateral teeth. Page ;w«. Fia. 8. A cast of the right valve of ^^^^^^^ „f ,^^ ,„terior muscular impression near .< 9 View of the anterior slope, shovMU}? tiie nm g " " '''" ^"■^- , of the valve showing the lateral teeth and impression of the elevated <« 10. The posterior .slope of tlie \ai\e, snu b muscular scar. PAh.'KorARDiA cnrwfiFOKMis, Hall. I'litSO .tSII. . ... A „f *i... . N..I lli-l .'II I AMI I I mil \M III M \ IM.,1,' \|\ I'l.ATi: xv Si un.iTKs \h:.\Tia<().:i s, 11m. h. Fi.i. I. View .Jl' an iiulivi.l.ml of tliitt K|K)cie8, Honunvhut ri-Htored in the upper part. Lo.\(t.\h:M.\ i.h:i>\, llM-i.. 1>„K,. ;(iis. Fi.». 2. Fi^ur. Iron, a K«tta-piTC»m cast takc-n in '.l.c nulu.al n.ouW; faint renuins of indistinct tranHverso striiB aro viBililo. KrSEMA? TI/II.I.SK.ITA, llM.h. I'liHr :IH7. Fl«. ;}. Kitturo talicn from a KUtta-perolia cast of il... natnr.l inoul.l in the rock. iVhuSKMA? Kh i:\.\TA, l/.\hl.. Piigo .tttl. Fiii. 4. View of a cast of this species. Th-'X'HO.SHMA {CifLiLXhMA.') rMfl.'H, IIm.L. rii«.' ;tii.",. Frn 5. View of the aperture, taken from a gulta-per.ha cast n.ii.lo in the natural mould. «< (3. Hasal view of tlie same specimen as li^. T,, sh.kwin- tlie nnil.ilicus. " 9. A small internal cast of this species. 7'/,'or//o.v/;.i/.i (/;r.Y /•;.!/. I) /•■.i/r.i, //.iaa. Fi.;. 7. View of an internal cast of this species. ,. . . , ., '« 8. The lij;ure is from a :,Mitta-percha cast, and shows the longitudmal striBB very perfectly. />hh:UliOTOMAIilA {THOCUO.SHMA) llOVI, HaLL. Page 3l«. Fig. 10. View of a cast cf this species. f'LKIh'ilTO.UAUIA (lfrll)i:.\S, HaIJj. rum' :!!fj. Fi« 11 Lateral view of a specimen of this species, which preserves a portion of the surface. <• 12. View of the spire, taken from a gutta-percha cast in the natural mould. PLEUROTOMAHIA llALKh ITai.l. Fio. 13. View of the spire of a cast of this species. " 14. The elevation of the spire. Plkihotomauia idia. Hall. Page 3il3. Figs. 15, 16. Vertical and lateral views of a cast of this species. port. lins of indistinct urul mould. triBB very perfectly. of the surface, uld. ^1 II. Mil- N.il I|i»l .'(» It \MT^°l«tl•>)t>^ n.u.. \v Fig Fig Fig Fks Fig Fig PLATE XV— Continued. Pleurotomahia axiox, Hall. Page 'AM. Fig. 17. View of a specimen of this species taken from a gutta-percha cast. Uo Lor KA a I HL p nKxsrs, B 1 1. 1. ixa s. PaReliid. Fig. 18. View of a cast which has been referred to this species. MVHCHISOXIA COiXHADI, HaLIj. ' Page 396. Fig. 19. View of a specimen of this species taken from a gutta-percha cast. MuRcmsoNiA r. Am A Ml, IT all. Page 31W. Fig. 20. The figure is from an impression taken in the natural mould, and shows the chaiacters of the surface and form of the aperture. S'lKAI'AIiOLJjI'S MOI'SCS, flAl.L. Pagf -.m. Figs. 21, 22. Upper and lower sides of a specimen of this species. Tremanotvs alphevs, Hall. I'age 31)!). Fig. 23. Lateral view of a specimen, showing the umbilicus. " 24. Dorsal view, showing the filling of the dorsal perforations, and the radiating striae near the aperture. PLATE XVI. TliOVUOCERAS NOTUM, HaLL. Page 403. Fio. 1. DorsaWiew of a fragment of this species. ^ ., , « 2. A septum showing its convexity and the position of the siphuncle. CYRTOCERAS RIGIDUM, HALL. Page 408.4 Fia. 3. Lateral view of the outer portion of the cast, showing the curvature of the shell and the character of the undulating ridges. " 4. Dorsal view of the same. " 5. Transverse section, showing the form. LiTUITES MARSHII, HAIjL. PnBe404. F.a. 6. Lateral view of a specimen of the natural size, showing the oblique costae and the out- .. 7. ProS'shotir'^" flattened dorsum, the concavity of the septa and the position of the siphuncle. , . Trociioceras desplainense, M'Chesney. Page 401. Fig. 8. View of the upper side of spire, taken from an impression in the natural mould in the rock, showing the strong oblique costffi. . . ,, . . ,u„ ^„^„ ^f th« << 9. Dorsal view of the outer part of the la-st volution, showing the smus m the margin of the .< 10. TranTverTe'section, showing the convexity of the septa and position of the siphuncle. Cyrtockras FosTERi, Hall. ' » Page 406. Fto. 11. Lateral view of the .specimen described. " 12 Dorsal view of the same. . . , ^,_ ■ v. .i. .. 13'. Transverse section, showing the convexity of the septa and position of the siphuncle. ..• Ml t le shell and the tee and the out- md the position al mould in the he margin of the the siphuncle. the siphuncle. •,: I... \liit- \.i: lli-i .'I' I I IMI \l ill'illi \ i'l.,1. Wl R T' Wl\i" ■•'..; ir. ■ii-'.cti iith PLATE XVIL OyvocKKAS oiiVAS, Hall. l>agu 410. F,G. 1. Dorsal view of a larsrc ^V^'^^- ^^^^ ,^ two-thirds the natural size. «' 2. Lateral view of the same. 1 ho tigurts ai i. ClltTOVEUAS UAHDANUS, HaLL. Page 406. .. 5". Transverse secu.. of the specimen ftg. 4. , ..L^actri IT'S WiNCn. AND MaR. Page 409. third in size. natural size. r and a small por- the dorsal margin. uter chamber, and IS are reduced one- ...•A'.r.'cn ;:'n Fir.. 1. " 2. " 3, Fui. 4. " 5 " G PLATE XV in. GoMPiiocEiiAS siiiiNirM, Hall, l'agL'410. Liiieral view of the outer chamber, the lower end showing the concavity of the septa. View of tlie aperture of the same individual. A transverse section of another individual, showing t'le size and position of the siphuncle, with muscular or vascular markings at the margin CYHTOCKIIAS LATKllALEs If A hi.. I'liKi^ 407. Dorsal view of a specimen, showing sciHa and preserving the remains of faint longitudinal ridges. . Lateral view of the same individual. , Tlie outer circle of the ligure represents the form of .section and the position of the siphuncle of this species,— the innar jwrtion that of C. lucillum. Ci'RTOCEKAS LUCIhLVM, HaLL. Page 406. lateral view of a specimen of this species. The figure is somewhat restored. See inner portion of figure for transvcr.se section. CiRTOCKHAS IlliEVICORXE, If ALL. I»iiKe 407. Lateral view of tlie specimen described. The specimen consists of the filling of the outer chamber and the matri.x of the lower part, which has been represented from a cast in the cavity. " 9. Dorsal view of the same. OkTUOCKKAS ABiXORSIE, HaLL. I'npc 415. Fig 10. View of a specimen of this species having the fdling of the chambers in the lower part broken away, showing the siphuncle, and the inner core with its numerous ranufica- tions uniting with the walls of the siphuncle. The view is taken looking oWiquely upon the specimen, so that the real amount of curvature is not observable. Fig. Fig. 8. i; I of the septa, of the siphuiicle, faint longitudinal e position of the itored. See inner Hling of the outer sented from a cast in the lower part lunierous raniifica- lookiufi obliquely servable. PLATE XIX. OliTUOCKHAa VREBBSCKIfS, HaLL. Page 413. Fio. 1 View of a large specimen, preserving the outer chiimber and several of the septa; the lower end showing the depth of the septa. " 2. View of another individual, having part of the septa in the lower end removed, and exposing the siphuncle. " 3. A smiiUer individual, which preserves traces of the longitudinal ridges. Orthoveras columnark, Hall. Page 411. Fig. 4. A fragment preserving the filling of four chambers, which are very distant. " 5. A transverse section of the lower end of the preceding specimen. «' 6. View of another specimen, preserving nine chambers, which are very irregular in their distances. In the upper part there is a small piece of the shell represented, showing the surface characters. «• 8. A fragment of this species of smaller size, preserving essentially the same characterB. Orthovkras loxias, Hall. Page 416. FtG. 7. Figure of specimen of natural size, preserving about seventeen of the septa, with the shell partially preserved, or replaced by mineral matter on the other parts of the surface. This species is not positively known in the Niagara limestone, and should therefore have been omitted from the index of the fossils of the Niagara group. OUTUOVKRAS ANOULATCM, WaIIL. Page 413. Fig. 9. a fragment of this species of about six inches in length, preserving above twenty septA and a part of the chamber of habitation ; from Racine, Wisconsin. " 10. From an impression of the exterior of a specimen similar to fig. 9, and from the same locality. . «« 11 From an impression of the exterior of a similar form, from Bridgeport, Ilhnois. The specimen , at a p^^ £!> -.Alii f 7"^" .,j»^f''"'''"f ■ MUOiM t » f.W %• 1-'-- •f:^ .«^- ^ 1 ■iw win wi'ja-iV^.y^T^^*' ■r- ■MiMiiiiiMiiil ,-,,,-, ' »' '')i<3«u .^M.f.-':<^%44* «. _.!»■•■*: .*«B<*»A'i«* *ft"w ■ llllll .«.,..> i' ' "' t"'"''^''^' "VH, — n"Mf!«>i Iff! ijj^ , -*- -^S T"' *--:.r ■■ i f r fffr' '1 " ."J^T^t'iV "¥1^^ MpiuuiMnMiji im v»' *^ m ui P W M>«wp||wp||pipti>wiip * i iillf yi ppi ir II I. w ill I I "l^pipp t •) M •4 •t IP In Jit pn J'LA 7'A' AX. OltrHOCKHAS MKDVl.LARS, Hm.L. Fid 1 A frapmcnt of a Ur^ indivia.ml, i.n-siTvii.g HeviTal of the wpta and a portion of the outer chainher. together with .•onHi.leral.le of the shell, showing the character of the exterior snrface. , • u i '■ 2. A section of the same individual, showing its elliptical forn. and the position of siphuncle. ONriioanKAS .\iA(J.\HK.\sj-:, H.\hh. I'llKO 41U Fio. 3. A view of the specimen descril^d, showing the obli(,ue undulations und several of the Hepta. OHTUOVEUAS ANJVULATUM, SoWERHY. PaKe411. Fio 4 A natural cast of the interior of a part of the ou* chamlHir. Tho annulations are very distinct and sharp, while the parallel encircling stri.w are very obscure or scarcely distinguisliable. The longitudinal ri.lges are unusually well preserved, and give a nodose character to the annulations. •' 5. A fragment of the septate portion of a si)t.ciinen of this species, showing the obscure impressions of longitudinal ridges with the annulatioiiH not strongly elevated. '< 6. A view of the upper extremity of Hg. 5, showing the broadly elliptical form of the sec- tion and tho position of the siphuncle. The New York specimens occur in soft calcureous shale, and often preserve the marks of obscure longitudinal ridges, interrupting the parallel transverse stri.u, giving a very obscurely nodose aspect to the surlace. This is shown in I'al. N. Y., Vol. ii, plate 64, tig. 1 a. Ihe same character is more distinctly shown in .Mi ii.ii.s.)n's Ixiautiful figure of this species, which m all its features corresponds with tho better preserved sp. omens in the Niagara group. Those from Illinois and Wisconsin present a great variety in the -legree of this marking, owing to the more or less complete solution and removal of tho shell and the nature of the enclosing material. In many specimens there are no nodes preserved on the surface. The undulating transverse striae are rarely well preserved, but they are quite distinct occasionally. Specimens also occur in which the undulating stria) and nodes are both well preserved The specimen, flg. 4, is quite an extreme one. portion of the le character of in of siphuncle. geveral of tb« itions are very are or scarcely ed, and give a ng the obHcure elevated. orin of the sec- larks of obscure iHCurely nodose same character all its features •oin Illinois and e more or less irial. In many iverse striae are ur in which the in extreme one. 1 of the racter of phuDcle. fil of the are very scarcely (I give a obscure d the sec- ■ obscure ' nodose haracter features nois and or less In many itriae are hich the jme one. |*W»iii**k" cheek of a small spLCuncn. \. enlarged to three diameters. " 7. The pygidium enlarged to two diameters. AcioAsris It A. \ A I. Hall. Page m. F„, 8 A .p«.h„,„ p.-c..vin, ,1k. ^^.* •«■< <'■»'■«« '■< •"« "'•""■'« -"■"■■""■ ™' "■=""■ '' " .. ., .i^::73:;s;:;;i:*x;;'i o,,:,....,,, „. .u. ...,-.. lo.^ of .. ,..- ^ bella. C'A/i'.HA'f.v .v/.k.'.i/.'a;a>7.s, JIall. Page 427. . <■ >f ti, . fi vpd rheeks of a specimen of this spe lies. LivuAS liKEVirKi's? Hall. " Page 424. 11 1 I. ,^f o ciii.piiiien enlarged to two diameters. Fir 12 The glabella and movable cheek of a sptcnntn, eniai,_(. « ' 13" Fi-nire of the internal ...st of a pygidinm ; natnra s./a-. .. u! An enlarged iignre of the lower snrface of a pygiduun. EsciiiM'iii'^ .v/;KA'f/«, Hall. Pago 425. Fm. 15. Figttre of the pygidiun. of this species enlarged to two diameters. DALMAMA VKIILANS, HaLL. , Page 426. disso;>-ed. " 18. Cast of a pygidinm of this species. ^ • liliOSTEUS ACAMAS, HaLL. Page 422. ViG 10 Cast of the glabella of this species, natural size. ^' 20. The pygidinm natural size, but slightly restored on one margin. St, III' Miif. N.ii llirti .'() (Ill s lAI I \ I'l.ll.' \\l the y.ropor- ligures are le fipure is of !S of the glu- es. WlNCHELL. St having been RF WKiUV-U.J PLATE XX 11. Jlla:nus AUMjrra. Hall. PagOB 41S, 433. Fio. 1. Upper view of the head of a well preseived individual. •' 2. Prolile view of tlie same. " 3. Tliu i)yni.liuiii aiul la.st thoracic segment, found associated with the head and supposed to lie of tlie saiiie species. iLI.-EMS (BrMASTIs) tOXi'S, IIaij.. Page 420. Fig. 4. Upper view of the head of a .small individual. " 5. Prolile view of the same. " 6. Upper view of a medium sized individual. '« 7. Lower view of the same, showin-f the extent of the infolding of the border, and the direc- tion of the suture on the under surface. Profile view of the same individual. The movable cheek of a larue specimen. A py-idium of the form commonly found associated with the other remains reterred to this species. A small j;labella, referred with doubt to this species. 8. 9. 10. " 11. Jij,.h;.\rs cvxicuLUS, Haij.. Page 421. Fiii. 12. View of the glabella of this species. jLLyEAUK lASlGNIS, IIaLL. Page 419. Fig. 13. The glabella and fixed cheeks, with the movable cheeks restored in outline. «' 14. The pygidium referred to this species. IiAj.ESUS IMPEHATOR, HaLL. Page 420. Fig. 15. The head of a large individual. The figure is reduced to one-half the natural size. " 16. The pygidium of a very small specimen of the species. " 17. The pygidium and parts of four of the thoracic segments, reduced in size one-half. sind supposed to r, anil the diiec- aiiis referred to ne. atural size, e one-half. •■^l Mil,- \.i| III, I ,'0 (•|l\ >i I \( I \ I'l.ii, Wll ■ III' I'la , an PLA TE XX J II. Ill^nvs (Bumastus) ioxus, Hall. Page 420. Fio. 1. The glahella and palpebral lobes of a large individual. IlL^NUS litfERATOR, HaLL. Page 420. Pis. 2. The glabella and palpebral lobes of a specimen of this species, natural size. " 3. The pygidium and part "r ir thoracic segments of this species, natural size. These figures represent tht ..dtural size of reduced figures 15 and 17 of Plate 22. SI,. I.' Ml Sh.ic- Mi]^ V.il llifi ■.'11 A-. ",! i-V ..V: I'"'. c ii\ >4r.\«v;.v Flm.- \XIII rwowtfa owwi MXM-^t^ feje ?;it;-::rr?rTC, nrsgji v PLATE XXIV. Orthoveras colcmaark, Hall. PaKo4n. Fio 1 View of a very fine specimen of tliis sp(U!ie8, showing the surface markings, form of the septa, size i.nd proportions of the siphuncle. From a specimen in the collection of Prof. Marry. Ortuoceras annvlatvm, Soweruy. Page 411. Fio '> A specimen (a cast of the interior) of this species, showing the septa and siphuncle. '« 3 A fragment, showing the angular form of the annulations and the lines of the septa. " 4. A fragment, showing the transverse or concentric undulating striae, and the longitudmal ridges, foru^ing nodes where they cross the annulations. Cyrtoceras later ale, Hall. Page 407. Fig f) View of a si^ecimen of this species, showing a few of the septa, and the outer chamber strongly constricted below the aperture. This figure is erroneously referred m the text to 0. alienum. Orthoveras alienum, Hall. i Page 414. Fig. 6. View of a cast of the outer chamber of this species, showing the gradually tapering form and the broad constriction near the aperture. " 7. A section of a fragment, showing the septa and siphuncle. Mill.' .Mil"* N.il.ll : 1 I 1 r Yi 7 ■iff ' nx . 1 ^ . 1 f e^^^ 1 ^■^'"•^ tt^3 ; _-; fr" .-■ M ^11 - :■ V\1llth(ild i'::: (I Pl'llAl.iil'iir)A.! I'l _'■». -*ei;:*H»^'«-rJ^.'j,i;^^- PLATE XXV. Oholus coNUAin, Hall. • Pl»K<'37B. Flu. 1. Interior oi' u vmitral viilve, iiinde from n cast in the natural mould. " 2. Interior of a sniulier ventral valve, olttaiiu'd \>\ the same jirrnx'ss as fig. 1. The dotted lines show the extent of the cavities lieneatli the transverse plate. " 3, Interior of a dorsal valve, taken from a trutta-percha cast in the natural mould. The lignre.s 2 ond i! lire from the same casts as those figured on plate 13. ISl'IRlFKHA I'l.lCATKI.LA. var. KADJATA, >So^^^. PBKe378. Fig. 4. Dorsal view of a larj^e cast, showing the cavities left hy the removal of the dental lamellje iind the septum of the dorsal valve. " Ti. Cardinal view of the same specimen as tig. 4, showing also the extent of the area. " 0. An oliliijue view of the interior of Iwth valves, showing the .septa and dental laniell»>. PEyTAMhhTs (PuivTAMKJiKLLA) rKXTHicosus, Hall. riiKe382. FiB». 7, 8. Dorsal a:ul front views of an individual, showing the plications more distinctly than usual. Plkurotomahia oci'wens. Hall. ♦ Pageaicj. Fio. 9. Lateral view of a very fine specimen, showing the external characters of the sjHicies. " 10. View of the aperture. Thi.s specimen is from the Niagara limestone of Lyons, Iowa, received from Dr. Farnsworlh. Plevrotomaria (Trovhonema) Hon, Hall. . Page 393. Figs. 11, 12. Lateral and basal views of a s{)ecimen of this species, showing the surface strire and the wide umbilicus. Trociwaama (CrcLoyhMA?) I'AurER, Hall. Page 395. Fig. 13. Lateral view of a specimen in the collection of the Michigan University, at Ann Arbor, received under the name of Pleurotomaria Halei. CyRTOCERAS BREVICORNE, HaLL. Page 407. Fig. 14. Lateral view of a specimen, showing the septa. Trochoceras costatvm, Hall. Page 402. Fig. 15. Lateral view of the upper surface, from a gutta-percha cast in the natural mould. ,si((i.' .MiM \,ii i / "■t-o^, .», j^ ^^' rjasaBa 15 -V w 9' w5WiJ3SE^^ii?3^«i^»i^e^i^iSi Mal.'Mii>« \.il Mist L'O. 'In' J r' f!^' B'v.'pn* C^ li'V. T'lala dt) Km li'>, Fio. 17. Fio. 18. ' Fro." lit. Fio. Uii. J Fi(» 21. \ Fio. 22. I * Trochoce tenud above nndetuniiiiK moderately oil the l)uck Snrlaoc in Miles of the the foi'incr o This sped flattening: ol wbicli it difl Formatio) FiiriiHworMi -1, 1^1 IM-ATK, XXV— ('(.nliniiwi \-. Fur 1(1. Via. 17, TlKKIKXia.WS .KSKAS.* II.M.t.. Vii-w .it I III. ii|>|>('i hiiil'iuf o," the N|HH-iiii(iii dcNniUMl. Tl{i>rii(,rh.i;.\S ((IVh'inHtAS) IIANMSTKItl. WlXril.d' M.Mt. View .,r the 8|.miii.-h takin In-in n -,ilti.-|.fr.lm .hnI, of tlio iin.l.ilirHl skIo shnwinir It to lie « (li'xtial N|K!('ii'N. Fru. 18. Fto.' lU. VhgP *IA. T.Hiisvor8i' , . M. ot 11 .s|Hriiiu.n. show in;, tli,. i„ii,ifving processes within the siphmiclo. J.lciiAs oinirs. IIai.Ij. I'llK" 4'il View 01 tht .sjiuLplU a...; Imenil lol«..> „r ,•, spcciim.n IVoin the Niagara liniostono at Ii.vonti, IvJivo. l.lrllAS rUOKAX. WlMii.^' Mai{. • I lit' pyfiidiimi of thi.s spe<'iis, finin the smiic sppciiiii'ii uk tlu- tlpiro by Mes.irs. Wincliell iiiiil Miircy, omitting the tiioraeii: segments, (.'ollectioii of Prof. Marcy. liRONTKrS AfAMAS. llAI.h. I'HKC ti2. \'ii'W of a small pygidiuni of this speeies. This llgure is from the ori)i;ina.l of lironteua orcamih, VV. & M. Ii.Ij.kms A um ATI'S, Ha I.I,. , l'airo4IH Pio. 22. A pygidium of this spei^ies, enlarged to two diameters, from a ,spe<'inien loaned by I'rof. Wincliell. The sixjcimen shows a broad oval im|)ressioii on each side of the median line and anterior to the middle. Similar marks have Injen observed on other specimens, and they may have licen tli^^ areas of muscular attachment. Fin. 'in. / Fig 21. ■I • Trockoceria wtiMs, nor. «/>.— Slicll sinUtral. I'loselv .'..ili'il. voliitloiiA s'<'ali'Bt .liametor or IIiiihr niua.^uritil, moderately concave, l.iit appearing nmi'i' deeply h.i IV.ini tlio HattoninK of'tlio volution; Rtronjfly arching forward.) on the bacli. and less stronRly on the ventral siilc .Snrlace marked hy moderately sharp nnitiilations which arc ilirccte.l backwards (Voni the inner to the outer Hides of the volution, and nrrangcd a liille more I'loaely than the septa, eleven of the latter equaling thirteen of the former on tlie doi^sal margin. This species dilTers from T. coKCiitmn. the only ..ther sinistral species occurring in the same association, in the flattening of the upper side; tlie ci.iu'entric nndiilations are liner than any other except T. llanninteri, fVoni wUicli it differs in the flattened ilorsuin formation and Mcn/Wj/.— In rocks of the Niagara group, at Lyons. Iowa. The specimen was received IVom Dr Funis worth . ^-^^^^Bm^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^' '" ^■iVgHF T - 'ig^rg